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Vol. 49 N° 8 - Avril 2010 [texte imprimé] . - 2010 . - p. 3505-3992 : ill. ; 28 cm. Chemical engineering Langues : Français (fre)
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Ajouter le résultat dans votre panierModel predictive control tuning methods / Jorge L. Garriga in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010)
Titre : Model predictive control tuning methods : A review Type de document : texte imprimé Auteurs : Jorge L. Garriga, Auteur ; Masoud Soroush, Auteur Année de publication : 2010 Article en page(s) : pp. 3505–3515 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Control tuning methods Résumé : This paper provides a review of the available tuning guidelines for model predictive control, from theoretical and practical perspectives. It covers both popular dynamic matrix control and generalized predictive control implementations, along with the more general state-space representation of model predictive control and other more specialized types, such as max-plus-linear model predictive control. Additionally, a section on state estimation and Kalman filtering is included along with auto (self) tuning. Tuning methods covered range from equations derived from simulation/approximation of the process dynamics to bounds on the region of acceptable tuning parameter values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900323c
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3505–3515[article] Model predictive control tuning methods : A review [texte imprimé] / Jorge L. Garriga, Auteur ; Masoud Soroush, Auteur . - 2010 . - pp. 3505–3515.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3505–3515
Mots-clés : Control tuning methods Résumé : This paper provides a review of the available tuning guidelines for model predictive control, from theoretical and practical perspectives. It covers both popular dynamic matrix control and generalized predictive control implementations, along with the more general state-space representation of model predictive control and other more specialized types, such as max-plus-linear model predictive control. Additionally, a section on state estimation and Kalman filtering is included along with auto (self) tuning. Tuning methods covered range from equations derived from simulation/approximation of the process dynamics to bounds on the region of acceptable tuning parameter values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900323c Exemplaires
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Titre : Photobioreactor design for commercial biofuel production from microalgae Type de document : texte imprimé Auteurs : aditya M. Kunjapur, Auteur ; R. bruce Eldridge, Auteur Année de publication : 2010 Article en page(s) : pp. 3516–3526 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photobioreactor biofuel Résumé : This review paper describes systems used to cultivate microalgae for biofuel production. It addresses general design considerations pertaining to reactors that use natural light and photosynthetic growth mechanisms, with an emphasis on large-scale reactors. Important design aspects include lighting, mixing, water consumption, CO2 consumption, O2 removal, nutrient supply, temperature, and pH. Though open pond reactors are the most affordable option, they provide insufficient control of nearly all growth conditions. In contrast, a variety of closed reactors offer substantial control, but few feature the likelihood for levels of productivity that offset their high cost. One of the greatest challenges of closed photobioreactor design is how to increase reactor size in order to benefit from economy of scale and produce meaningful quantities of biofuel. This paper also highlights the concept of combining open and closed systems and concludes with a discussion regarding a possible optimal reactor configuration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901459u
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3516–3526[article] Photobioreactor design for commercial biofuel production from microalgae [texte imprimé] / aditya M. Kunjapur, Auteur ; R. bruce Eldridge, Auteur . - 2010 . - pp. 3516–3526.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3516–3526
Mots-clés : Photobioreactor biofuel Résumé : This review paper describes systems used to cultivate microalgae for biofuel production. It addresses general design considerations pertaining to reactors that use natural light and photosynthetic growth mechanisms, with an emphasis on large-scale reactors. Important design aspects include lighting, mixing, water consumption, CO2 consumption, O2 removal, nutrient supply, temperature, and pH. Though open pond reactors are the most affordable option, they provide insufficient control of nearly all growth conditions. In contrast, a variety of closed reactors offer substantial control, but few feature the likelihood for levels of productivity that offset their high cost. One of the greatest challenges of closed photobioreactor design is how to increase reactor size in order to benefit from economy of scale and produce meaningful quantities of biofuel. This paper also highlights the concept of combining open and closed systems and concludes with a discussion regarding a possible optimal reactor configuration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901459u Exemplaires
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Titre : Photodegradation of sulfadiazine by goethite - oxalates uspension under UV light irradiation Type de document : texte imprimé Auteurs : Yan Wang, Auteur ; juan boo Liang, Auteur ; xin di Liao, Auteur Année de publication : 2010 Article en page(s) : pp. 3527–3532 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photodegradation UV light Résumé : Sulfadiazine, a potent antibacterial agent belonging to the group of antibiotics called sulfonamides, has been reported to be present in surface and groundwater. This study investigated the degradation of sulfadiazine in a goethite (α-FeOOH)−oxalate Fenton-like system under UV irradiation. The results showed that sulfadiazine could be effectively photodegraded by the goethite−oxalate Fenton-like system as a result of the formation of the highly oxidizing hydroxyl radicals, •OH. Among the iron oxides tested (α-FeOOH, γ-Fe2O3, γ-FeOOH, and α-Fe2O3), α-FeOOH was found to be the most effective. Degradation of sulfadiazine depended significantly on the pH and initial concentration of oxalic acid in the system, with optimal values of 3.5 and 4.0 mM, respectively, under UV irradiation. Five intermediate products of sulfadiazine degradation were identified using high-performance liquid chromatography−mass spectrometry (HPLC−MS), gas chromatography−mass spectrometry (GC−MS), and ion chromatography (IC), and a possible sulfadiazine degradation pathway in such a system was proposed. Organic sulfur and organic nitrogen mineralization were also observed, and the results indicated that cleavage of the sulfonylurea bridge was easier than the other potential cleavage bonds under the goethite−oxalate system. In addition, results from Biolog assays suggested that the ecological toxicity of the sulfadiazine solution was effectively reduced after degradation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014974
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3527–3532[article] Photodegradation of sulfadiazine by goethite - oxalates uspension under UV light irradiation [texte imprimé] / Yan Wang, Auteur ; juan boo Liang, Auteur ; xin di Liao, Auteur . - 2010 . - pp. 3527–3532.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3527–3532
Mots-clés : Photodegradation UV light Résumé : Sulfadiazine, a potent antibacterial agent belonging to the group of antibiotics called sulfonamides, has been reported to be present in surface and groundwater. This study investigated the degradation of sulfadiazine in a goethite (α-FeOOH)−oxalate Fenton-like system under UV irradiation. The results showed that sulfadiazine could be effectively photodegraded by the goethite−oxalate Fenton-like system as a result of the formation of the highly oxidizing hydroxyl radicals, •OH. Among the iron oxides tested (α-FeOOH, γ-Fe2O3, γ-FeOOH, and α-Fe2O3), α-FeOOH was found to be the most effective. Degradation of sulfadiazine depended significantly on the pH and initial concentration of oxalic acid in the system, with optimal values of 3.5 and 4.0 mM, respectively, under UV irradiation. Five intermediate products of sulfadiazine degradation were identified using high-performance liquid chromatography−mass spectrometry (HPLC−MS), gas chromatography−mass spectrometry (GC−MS), and ion chromatography (IC), and a possible sulfadiazine degradation pathway in such a system was proposed. Organic sulfur and organic nitrogen mineralization were also observed, and the results indicated that cleavage of the sulfonylurea bridge was easier than the other potential cleavage bonds under the goethite−oxalate system. In addition, results from Biolog assays suggested that the ecological toxicity of the sulfadiazine solution was effectively reduced after degradation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014974 Exemplaires
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Titre : Fractional catalytic of hybrid poplar wood Type de document : texte imprimé Auteurs : Foster. A. Agblevor, Auteur ; S. Beis, Auteur ; O. Mante, Auteur Année de publication : 2010 Article en page(s) : 3533-3537 P. Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : pyrolysis Fractional catalytic hybrid poplar wood Résumé : Fractional catalytic pyrolysis is a selective in situ conversion of biopolymers into desired products. Fractional catalytic pyrolysis was used to convert the lignin fraction of hybrid poplar wood into high yields of cresols and phenols while the carbohydrate fraction was selectively converted into gaseous products. Ground air-dried biomass was fractionally pyrolyzed at 450−500 °C in a 2-in fluidized bed reactor. The total liquid, gas, and char/coke yields were 33%, 53%, and 12.5%, respectively. The low viscosity liquid products consisted of almost pure phenolics with minor carbohydrate decomposition products. The major liquid components were phenol, cresols, methyl substituted phenols, and small fractions of indene and substituted naphthalenes. The carbon and oxygen contents and high heating value (HHV) of the oil were 71%, 21%, and 30.5 MJ/kg, respectively. About 90 wt % of the gaseous products was carbon monoxide and carbon dioxide, and the rest was a mixture of hydrocarbons. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901629r?prevSearch=Fractional%2Bcatalytic% [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - 3533-3537 P.[article] Fractional catalytic of hybrid poplar wood [texte imprimé] / Foster. A. Agblevor, Auteur ; S. Beis, Auteur ; O. Mante, Auteur . - 2010 . - 3533-3537 P.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - 3533-3537 P.
Mots-clés : pyrolysis Fractional catalytic hybrid poplar wood Résumé : Fractional catalytic pyrolysis is a selective in situ conversion of biopolymers into desired products. Fractional catalytic pyrolysis was used to convert the lignin fraction of hybrid poplar wood into high yields of cresols and phenols while the carbohydrate fraction was selectively converted into gaseous products. Ground air-dried biomass was fractionally pyrolyzed at 450−500 °C in a 2-in fluidized bed reactor. The total liquid, gas, and char/coke yields were 33%, 53%, and 12.5%, respectively. The low viscosity liquid products consisted of almost pure phenolics with minor carbohydrate decomposition products. The major liquid components were phenol, cresols, methyl substituted phenols, and small fractions of indene and substituted naphthalenes. The carbon and oxygen contents and high heating value (HHV) of the oil were 71%, 21%, and 30.5 MJ/kg, respectively. About 90 wt % of the gaseous products was carbon monoxide and carbon dioxide, and the rest was a mixture of hydrocarbons. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901629r?prevSearch=Fractional%2Bcatalytic% [...] Exemplaires
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Titre : Highly sensitive and selective alcohol sensors based on ag-doped In2 O3 coating Type de document : texte imprimé Auteurs : Yidong Zhang, Auteur ; Zhi Zheng, Auteur ; Fengling Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 3539-3543 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Alcohol Sensors Ag-Doped In2 O3 Coating Résumé : In this paper, we describe how to synthesize Ag-doped In2O3 nano particles and fabricate highly sensitive and selective alcohol sensors by solid-state reaction treatment from In(NO3)3·5H2O and AgNO3 mixtures at room temperature followed by calcination at 600 °C for 2 h. The samples were characterized by X-ray diffraction, scanning electronic microscopy, X-ray photoelectron spectroscopy. The diameter of the as-synthesized particle diameter is 80 nm under different dosage of Ag doping. In comparison with pure In2O3 sensor, all of the Ag-doped sensors showed better sensing performance in sensitivity, selectivity and optimum operating temperature. The effects of Ag content, alcohol vapor concentration, and operating temperature on the sensing characteristics of the Ag-doped In2O3 sensors were also investigated. We found that the Ag-doped sensor containing 10.0 mol % Ag exhibited the maximum sensitivity to alcohol vapor at 150 °C. A possible mechanism for the influence of Ag on the alcohol-sensing properties of Ag-doped In2O3 sensors was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100197b?prevSearch=Highly%2Bsensitive%2Ban [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3539-3543[article] Highly sensitive and selective alcohol sensors based on ag-doped In2 O3 coating [texte imprimé] / Yidong Zhang, Auteur ; Zhi Zheng, Auteur ; Fengling Yang, Auteur . - 2010 . - pp. 3539-3543.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3539-3543
Mots-clés : Alcohol Sensors Ag-Doped In2 O3 Coating Résumé : In this paper, we describe how to synthesize Ag-doped In2O3 nano particles and fabricate highly sensitive and selective alcohol sensors by solid-state reaction treatment from In(NO3)3·5H2O and AgNO3 mixtures at room temperature followed by calcination at 600 °C for 2 h. The samples were characterized by X-ray diffraction, scanning electronic microscopy, X-ray photoelectron spectroscopy. The diameter of the as-synthesized particle diameter is 80 nm under different dosage of Ag doping. In comparison with pure In2O3 sensor, all of the Ag-doped sensors showed better sensing performance in sensitivity, selectivity and optimum operating temperature. The effects of Ag content, alcohol vapor concentration, and operating temperature on the sensing characteristics of the Ag-doped In2O3 sensors were also investigated. We found that the Ag-doped sensor containing 10.0 mol % Ag exhibited the maximum sensitivity to alcohol vapor at 150 °C. A possible mechanism for the influence of Ag on the alcohol-sensing properties of Ag-doped In2O3 sensors was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100197b?prevSearch=Highly%2Bsensitive%2Ban [...] Exemplaires
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Titre : Model-based analysis of reactor feeding policies for methane oxidative coupling Type de document : texte imprimé Auteurs : H. R. Godini, Auteur ; H. Arellano-Garcia, Auteur ; M. Omidkhah, Auteur Année de publication : 2010 Article en page(s) : pp. 3544–3552 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Reactor Feeding Policies Methane Oxidative Coupling Résumé : In this work, a new feeding policy structure for an alternative operation mode of the packed bed membrane reactor (PBMR) is proposed in order to increase the efficiency of the OCM—oxidative coupling of methane—process. This structure has a high potential to improve the process performance in comparison to fixed bed reactors (PFRs) and even to a conventional PBMR design structure. The main drawbacks in operating PFR or PBMR have been to find suitable operation policies toward the enhancement of both yield and selectivity at the same time. In this work, a model-based comparative study of the OCM process performance for these three reactors types is presented. For this purpose, the effect of oxygen accessibility in the different design structures is investigated. Basically, the new proposed feeding policy structure combines the advantages of PFR and the conventional PBMR so as to get a high yield amount by cofeeding methane and oxygen into the reactor entrance while guaranteeing an acceptable level of selectivity by reducing the accessibility to ethylene and oxygen, in particular, at the reactor end. Moreover, using the potential of the proposed operation mode, it is now possible to build a reactor network consisting of the new proposed and the conventional PBMR in order to treat the shell side gas streams, which results from each PBMR structure. The analysis of the proposed reactor network shows a performance of 23.21% yield, 53.93% selectivity, and 42.66% methane conversion, respectively. Besides, a sensitivity analysis is performed in order to analyze the effect of reactant accessibility in the proposed feeding policy structure. The results are analyzed along with the study of the optimal operating range in order to conceptually design a membrane reactor network toward satisfying economical and industrial considerations in terms of selectivity, one-pass yield, and methane conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900182q?prevSearch=Model-based%2Banalysis% [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3544–3552[article] Model-based analysis of reactor feeding policies for methane oxidative coupling [texte imprimé] / H. R. Godini, Auteur ; H. Arellano-Garcia, Auteur ; M. Omidkhah, Auteur . - 2010 . - pp. 3544–3552.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3544–3552
Mots-clés : Reactor Feeding Policies Methane Oxidative Coupling Résumé : In this work, a new feeding policy structure for an alternative operation mode of the packed bed membrane reactor (PBMR) is proposed in order to increase the efficiency of the OCM—oxidative coupling of methane—process. This structure has a high potential to improve the process performance in comparison to fixed bed reactors (PFRs) and even to a conventional PBMR design structure. The main drawbacks in operating PFR or PBMR have been to find suitable operation policies toward the enhancement of both yield and selectivity at the same time. In this work, a model-based comparative study of the OCM process performance for these three reactors types is presented. For this purpose, the effect of oxygen accessibility in the different design structures is investigated. Basically, the new proposed feeding policy structure combines the advantages of PFR and the conventional PBMR so as to get a high yield amount by cofeeding methane and oxygen into the reactor entrance while guaranteeing an acceptable level of selectivity by reducing the accessibility to ethylene and oxygen, in particular, at the reactor end. Moreover, using the potential of the proposed operation mode, it is now possible to build a reactor network consisting of the new proposed and the conventional PBMR in order to treat the shell side gas streams, which results from each PBMR structure. The analysis of the proposed reactor network shows a performance of 23.21% yield, 53.93% selectivity, and 42.66% methane conversion, respectively. Besides, a sensitivity analysis is performed in order to analyze the effect of reactant accessibility in the proposed feeding policy structure. The results are analyzed along with the study of the optimal operating range in order to conceptually design a membrane reactor network toward satisfying economical and industrial considerations in terms of selectivity, one-pass yield, and methane conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900182q?prevSearch=Model-based%2Banalysis% [...] Exemplaires
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Titre : Study on the fuel-reforming-assisted hydrocarbon selective catalytic reduction over silver/alumina catalyst Type de document : texte imprimé Auteurs : Jaewook Lee, Auteur ; Soonho Song, Auteur ; Kwang Min Chun, Auteur Année de publication : 2010 Article en page(s) : pp. 3553–3560 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Hydrocarbon Selective Catalytic Reduction Catalyst Résumé : This study aims to assess the feasibility of fuel-reforming-assisted hydrocarbon selective catalytic reduction (HC-SCR) over 2 wt % Ag/Al2O3 catalyst. For this purpose, the effects of reduction agents and the presence of hydrogen on NOx reduction over silver catalyst were tested, and, after catalytic partial oxidation (CPOx) reforming performances were studied, the DeNOx performance of reformate-assisted HC-SCR was investigated. Although normal heptane/octane/dodecane showed better NOx reduction rates at 300 and 350 °C than the other C2−C4 range hydrocarbons, the performances were still unpractical at the temperature range similar to actual diesel exhaust. To enhance the low temperature activity of the Ag/Al2O3 catalyst, CPOx reforming was tested and applied in the SCR system. By the addition of CPOx products to the HC-SCR reactor, NOx reduction performance was increased to a great extent especially in the low temperature range between 200 and 400 °C. For the reductant condition of C/N = 6 + CPOx/N = 6 without water, about 52.5% of NOx reduction was recorded over C3H6-SCR at 300 °C, whereas nearly zero DeNOx efficiency was measured when only C3H6 was present in the reactants. Also, it was found that C/N = 6 + CPOx/N = 6 showed the better NOx reduction efficiency than C/N = 3 + CPOx/N = 9. Together with the hydrogen model gas tests results, it implies that there is an optimum hydrogen to hydrocarbon ratio in terms of low-temperature activity enhancement assuming that the total amount of fuel used in CPOx-assisted HC-SCR is the same. In addition, inhibition effect by water was reduced to an extent by CPOx products. C3H6-SCR was deactivated so seriously that no NOx conversions were measured at 300 and 400 °C in the presence of water vapor. However, through the addition of CPOx products to the C3H6-SCR reactants, NOx reduction was increased to 20% at 300 °C and 25% at 400 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015528?prevSearch=Study%2Bon%2Bthe%2Bfuel [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3553–3560[article] Study on the fuel-reforming-assisted hydrocarbon selective catalytic reduction over silver/alumina catalyst [texte imprimé] / Jaewook Lee, Auteur ; Soonho Song, Auteur ; Kwang Min Chun, Auteur . - 2010 . - pp. 3553–3560.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3553–3560
Mots-clés : Hydrocarbon Selective Catalytic Reduction Catalyst Résumé : This study aims to assess the feasibility of fuel-reforming-assisted hydrocarbon selective catalytic reduction (HC-SCR) over 2 wt % Ag/Al2O3 catalyst. For this purpose, the effects of reduction agents and the presence of hydrogen on NOx reduction over silver catalyst were tested, and, after catalytic partial oxidation (CPOx) reforming performances were studied, the DeNOx performance of reformate-assisted HC-SCR was investigated. Although normal heptane/octane/dodecane showed better NOx reduction rates at 300 and 350 °C than the other C2−C4 range hydrocarbons, the performances were still unpractical at the temperature range similar to actual diesel exhaust. To enhance the low temperature activity of the Ag/Al2O3 catalyst, CPOx reforming was tested and applied in the SCR system. By the addition of CPOx products to the HC-SCR reactor, NOx reduction performance was increased to a great extent especially in the low temperature range between 200 and 400 °C. For the reductant condition of C/N = 6 + CPOx/N = 6 without water, about 52.5% of NOx reduction was recorded over C3H6-SCR at 300 °C, whereas nearly zero DeNOx efficiency was measured when only C3H6 was present in the reactants. Also, it was found that C/N = 6 + CPOx/N = 6 showed the better NOx reduction efficiency than C/N = 3 + CPOx/N = 9. Together with the hydrogen model gas tests results, it implies that there is an optimum hydrogen to hydrocarbon ratio in terms of low-temperature activity enhancement assuming that the total amount of fuel used in CPOx-assisted HC-SCR is the same. In addition, inhibition effect by water was reduced to an extent by CPOx products. C3H6-SCR was deactivated so seriously that no NOx conversions were measured at 300 and 400 °C in the presence of water vapor. However, through the addition of CPOx products to the C3H6-SCR reactants, NOx reduction was increased to 20% at 300 °C and 25% at 400 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015528?prevSearch=Study%2Bon%2Bthe%2Bfuel [...] Exemplaires
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Titre : Isoamylene trimerzization in liquid-phase over ino exchange resins and zeolites Type de document : texte imprimé Auteurs : Marta Granollers, Auteur ; José F. Izquierdo, Auteur ; Javier Tejero, Auteur Année de publication : 2010 Article en page(s) : pp. 3561–3570 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Isoamylene Trimerization Liquid-Phase Ion Exchange Resins Zeolites Résumé : Liquid-phase trimerization of 2-methyl-1-butene and 2-methyl-2-butene mixtures over solid acid catalysts was carried out in a batch-stirred tank reactor in the temperature range 333−373 K. Diisoamylenes and triisoamylenes were the main products. Cracking products among C6−C9 and C11−C14 were also obtained under the assayed conditions. The catalityc performance of five different acidic ion exchange resins (Amberlyst 15, Amberlyst 35, Amberlyst 70, Purolite CT-252, Purolite CT-276) and four zeolites (H-BEA-25, H-FAU-30, H-FAU-6 and H-MOR-20) was assessed. Experimental results showed that Amberlyst 15 and H-FAU-30 were the best catalysts for isoamylene trimerization, with selectivities above 40% at 373 K. The most influencing physical properties of the catalysts on the selectivity toward dimers and trimers were acid capacity, acid strength, and specific surface area for resins, and microporous surface area for zeolites. Isoamylene trimerization extent was larger at higher temperature. The most probable mechanism of formation of these compounds involves the reaction between one molecule of dimer with one molecule of isoamylenes, although trimers could also be formed directly from three molecules of isoamylenes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901382p?journalCode=iecred
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3561–3570[article] Isoamylene trimerzization in liquid-phase over ino exchange resins and zeolites [texte imprimé] / Marta Granollers, Auteur ; José F. Izquierdo, Auteur ; Javier Tejero, Auteur . - 2010 . - pp. 3561–3570.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3561–3570
Mots-clés : Isoamylene Trimerization Liquid-Phase Ion Exchange Resins Zeolites Résumé : Liquid-phase trimerization of 2-methyl-1-butene and 2-methyl-2-butene mixtures over solid acid catalysts was carried out in a batch-stirred tank reactor in the temperature range 333−373 K. Diisoamylenes and triisoamylenes were the main products. Cracking products among C6−C9 and C11−C14 were also obtained under the assayed conditions. The catalityc performance of five different acidic ion exchange resins (Amberlyst 15, Amberlyst 35, Amberlyst 70, Purolite CT-252, Purolite CT-276) and four zeolites (H-BEA-25, H-FAU-30, H-FAU-6 and H-MOR-20) was assessed. Experimental results showed that Amberlyst 15 and H-FAU-30 were the best catalysts for isoamylene trimerization, with selectivities above 40% at 373 K. The most influencing physical properties of the catalysts on the selectivity toward dimers and trimers were acid capacity, acid strength, and specific surface area for resins, and microporous surface area for zeolites. Isoamylene trimerization extent was larger at higher temperature. The most probable mechanism of formation of these compounds involves the reaction between one molecule of dimer with one molecule of isoamylenes, although trimers could also be formed directly from three molecules of isoamylenes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901382p?journalCode=iecred Exemplaires
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Titre : Kinetice and thermodynamics of zine phosphate hydrate synthesized by a simple rout in aqueous and acetone media Type de document : texte imprimé Auteurs : Banjong Boonchom, Auteur ; Rattanai Baitahe, Auteur ; Samart Kongtaweelert, Auteur Année de publication : 2010 Article en page(s) : pp. 3571–3576 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Thermodynamics Zinc Phosphate Hydrate Acetone Résumé : Zinc phosphate (Zn3(PO4)2·4H2O) was prepared by a simple route using ZnO and H3PO4 in aqueous and acetone media at ambient temperature. Zn3(PO4)2·4H2O decomposes to Zn3(PO4)2 by three dehydration reactions, as revealed by thermal analytical (TG/DTG/DTA) and differential scanning calorimetry (DSC) techniques. The synthesized Zn3(PO4)2·4H2O and its dehydration product Zn3(PO4)2 were characterized by powder X-ray diffraction, Fourier transfer infrared, and scanning electron microscopy. Kinetic triplet parameters (activation energy, E; preexponential, A; Avrami exponent, n) and thermodynamic functions (ΔH*, ΔG*, and ΔS*) of three dehydration reactions are calculated by DSC experiments. Evaluation and control of the specific characteristics of three dehydration processes of Zn3(PO4)2·4H2O are essentially important in the variously oriented studies, which were discussed from the viewpoints of thermal stability based on kinetics and thermodynamics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901626z
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3571–3576[article] Kinetice and thermodynamics of zine phosphate hydrate synthesized by a simple rout in aqueous and acetone media [texte imprimé] / Banjong Boonchom, Auteur ; Rattanai Baitahe, Auteur ; Samart Kongtaweelert, Auteur . - 2010 . - pp. 3571–3576.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3571–3576
Mots-clés : Thermodynamics Zinc Phosphate Hydrate Acetone Résumé : Zinc phosphate (Zn3(PO4)2·4H2O) was prepared by a simple route using ZnO and H3PO4 in aqueous and acetone media at ambient temperature. Zn3(PO4)2·4H2O decomposes to Zn3(PO4)2 by three dehydration reactions, as revealed by thermal analytical (TG/DTG/DTA) and differential scanning calorimetry (DSC) techniques. The synthesized Zn3(PO4)2·4H2O and its dehydration product Zn3(PO4)2 were characterized by powder X-ray diffraction, Fourier transfer infrared, and scanning electron microscopy. Kinetic triplet parameters (activation energy, E; preexponential, A; Avrami exponent, n) and thermodynamic functions (ΔH*, ΔG*, and ΔS*) of three dehydration reactions are calculated by DSC experiments. Evaluation and control of the specific characteristics of three dehydration processes of Zn3(PO4)2·4H2O are essentially important in the variously oriented studies, which were discussed from the viewpoints of thermal stability based on kinetics and thermodynamics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901626z Exemplaires
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Titre : Alternative reforming methods of primary tar released from gas treatment of biomass at low temperature for development of pyrolysis/gasification process Type de document : texte imprimé Auteurs : Weerawut Chaiwat, Auteur ; Isao Hasegawa, Auteur ; Kazuhiro Mae, Auteur Année de publication : 2010 Article en page(s) : pp. 3577–3584 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Alternative Reforming Methods Primary Tar Released Gas Treatment Biomass Temperature Résumé : Primary tars produced from gas treatment in a low-temperature region were confirmed by thermogravimetric analysis of tar-mixed biomass that they would be easily handled by using simple reforming methods. A two-stage reactor was used to investigate the secondary reaction of light tar decomposition. The effect of air on light tar decomposition showed that gas products increased when the upper temperature was increased from 600 to 900 °C. When biomass char pyrolyzed to 900 °C was loaded in the upper reactor, the decomposition of light tar under inert atmosphere occurred by steam reforming to produce fuel gases even at a low temperature of 600 °C. When the upper temperature was increased to 800−900 °C, the yield of light tar significantly decreased and became almost zero because steam reforming and related reactions could proceed to produce CO and CO2 even in the case without biomass char. However, CO could be selectively obtained at the highest yield of 24.0 wt % because of the effect of catalytic char at a high temperature of 900 °C. Finally, alternative methods of light tar reforming are discussed for the development of a biomass gasification process to obtain tar-free gaseous products and/or valuable chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901695r?prevSearch=Alternative%2Breforming [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3577–3584[article] Alternative reforming methods of primary tar released from gas treatment of biomass at low temperature for development of pyrolysis/gasification process [texte imprimé] / Weerawut Chaiwat, Auteur ; Isao Hasegawa, Auteur ; Kazuhiro Mae, Auteur . - 2010 . - pp. 3577–3584.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3577–3584
Mots-clés : Alternative Reforming Methods Primary Tar Released Gas Treatment Biomass Temperature Résumé : Primary tars produced from gas treatment in a low-temperature region were confirmed by thermogravimetric analysis of tar-mixed biomass that they would be easily handled by using simple reforming methods. A two-stage reactor was used to investigate the secondary reaction of light tar decomposition. The effect of air on light tar decomposition showed that gas products increased when the upper temperature was increased from 600 to 900 °C. When biomass char pyrolyzed to 900 °C was loaded in the upper reactor, the decomposition of light tar under inert atmosphere occurred by steam reforming to produce fuel gases even at a low temperature of 600 °C. When the upper temperature was increased to 800−900 °C, the yield of light tar significantly decreased and became almost zero because steam reforming and related reactions could proceed to produce CO and CO2 even in the case without biomass char. However, CO could be selectively obtained at the highest yield of 24.0 wt % because of the effect of catalytic char at a high temperature of 900 °C. Finally, alternative methods of light tar reforming are discussed for the development of a biomass gasification process to obtain tar-free gaseous products and/or valuable chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901695r?prevSearch=Alternative%2Breforming [...] Exemplaires
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Titre : Numerical simulation of fluid dyanmics of a riser : influence of particle rotation Type de document : texte imprimé Auteurs : Zhenhua Hao, Auteur ; Shuai Wang, Auteur ; Huilin Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 3585–3596 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Numerical Simulation Fluid Dynamics Particle Rotation Résumé : Flow behavior of gas and particles in a 2-D riser is simulated using a gas−solid two-fluid model with consideration of the effect of particle rotation. The particle−particle interactions are simulated from the kinetic theory for flow of dense, slightly inelastic, slightly rough spheres proposed by Lun (Lun, C. K. K. Kinetic theory for granular flow of dense, slightly inelastic, slightly rough sphere. J. Fluid Mech. 1991, 233, 539−559). Inelastic binary collisions of particles with normal and tangential restitution coefficients are considered. The modified expressions for energy dissipation and viscosities of particles are proposed as a function of tangential and normal restitution coefficients of particles. The present model is evaluated by the measured solids concentration and velocities of Miller and Gidaspow (Miller, A.; Gidaspow. D. Dense, vertical gas-solid flow in a pipe. AIChE J. 1992, 38, 1801−1815), and the measured solids concentration, mass flux, and pressure drop of Knowlton et al. (Knowlton, T.; Geldart, D.; Matsen, J.; King, D. Comparison of CFB hydrodynamic models. PSRI challenge problem. Presented at the Eighth International Fluidization Conference, Tours, France, May 1995) in the risers. Computed profiles of particles are in agreement with the experimental measurements. The simulated energy dissipation, granular temperature, viscosity, and thermal conductivity of particles exhibit nonmonotonic tangential restitution coefficient dependences due to the energy losses resulting from particle collisions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019243
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3585–3596[article] Numerical simulation of fluid dyanmics of a riser : influence of particle rotation [texte imprimé] / Zhenhua Hao, Auteur ; Shuai Wang, Auteur ; Huilin Lu, Auteur . - 2010 . - pp. 3585–3596.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3585–3596
Mots-clés : Numerical Simulation Fluid Dynamics Particle Rotation Résumé : Flow behavior of gas and particles in a 2-D riser is simulated using a gas−solid two-fluid model with consideration of the effect of particle rotation. The particle−particle interactions are simulated from the kinetic theory for flow of dense, slightly inelastic, slightly rough spheres proposed by Lun (Lun, C. K. K. Kinetic theory for granular flow of dense, slightly inelastic, slightly rough sphere. J. Fluid Mech. 1991, 233, 539−559). Inelastic binary collisions of particles with normal and tangential restitution coefficients are considered. The modified expressions for energy dissipation and viscosities of particles are proposed as a function of tangential and normal restitution coefficients of particles. The present model is evaluated by the measured solids concentration and velocities of Miller and Gidaspow (Miller, A.; Gidaspow. D. Dense, vertical gas-solid flow in a pipe. AIChE J. 1992, 38, 1801−1815), and the measured solids concentration, mass flux, and pressure drop of Knowlton et al. (Knowlton, T.; Geldart, D.; Matsen, J.; King, D. Comparison of CFB hydrodynamic models. PSRI challenge problem. Presented at the Eighth International Fluidization Conference, Tours, France, May 1995) in the risers. Computed profiles of particles are in agreement with the experimental measurements. The simulated energy dissipation, granular temperature, viscosity, and thermal conductivity of particles exhibit nonmonotonic tangential restitution coefficient dependences due to the energy losses resulting from particle collisions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019243 Exemplaires
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Titre : Reaction mechanism and kinetic analysis of the decomposition of phosphogypsum via a solid-state reaction Type de document : texte imprimé Auteurs : Liping Ma, Auteur ; Ping Ning, Auteur ; Shaocong Zheng, Auteur Année de publication : 2010 Article en page(s) : pp. 3597–3602 Note générale : Indusrrial Chemistry Langues : Anglais (eng) Mots-clés : Reaction Mechanism Kinetic Analysis Decomposition Phosphogypsum Solid-State Résumé : Phosphogypsum decomposition is very complex because of its complicated compounds. In this study, using high-sulfur-concentration coal as a reducer, thermogravimetric analysis, differential thermal analysis, scanning electron microscopy, and X-ray diffraction were used to characterize the decomposition process of phosphogypsum in a nitrogen atmosphere at different conditions. Mechanism analysis and experiment results showed that the amount of the intermediate production of CaS depended on the heating rate and the size of coal used, which was produced mainly through the reaction between CaSO4 and C, and production would decrease with an increase of the coal size. 60 mesh was a suitable size of coal for phosphogypsum decomposition to get high recovery of the main production of CaO. Using Kissinger, Flynn−Wall−Ozaw, and Coats−Redfem methods, the mechanism model of phosphogypsum decomposition was confirmed, the decomposition process belonged to the core-form and growing mechanism (n = 2), and the kinetic model was dα/dt = 1.6 × 1016e−475.99×103/RT × 2(1 − α)[−ln(1 − α)]1/2, where α is conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901950y
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3597–3602[article] Reaction mechanism and kinetic analysis of the decomposition of phosphogypsum via a solid-state reaction [texte imprimé] / Liping Ma, Auteur ; Ping Ning, Auteur ; Shaocong Zheng, Auteur . - 2010 . - pp. 3597–3602.
Indusrrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3597–3602
Mots-clés : Reaction Mechanism Kinetic Analysis Decomposition Phosphogypsum Solid-State Résumé : Phosphogypsum decomposition is very complex because of its complicated compounds. In this study, using high-sulfur-concentration coal as a reducer, thermogravimetric analysis, differential thermal analysis, scanning electron microscopy, and X-ray diffraction were used to characterize the decomposition process of phosphogypsum in a nitrogen atmosphere at different conditions. Mechanism analysis and experiment results showed that the amount of the intermediate production of CaS depended on the heating rate and the size of coal used, which was produced mainly through the reaction between CaSO4 and C, and production would decrease with an increase of the coal size. 60 mesh was a suitable size of coal for phosphogypsum decomposition to get high recovery of the main production of CaO. Using Kissinger, Flynn−Wall−Ozaw, and Coats−Redfem methods, the mechanism model of phosphogypsum decomposition was confirmed, the decomposition process belonged to the core-form and growing mechanism (n = 2), and the kinetic model was dα/dt = 1.6 × 1016e−475.99×103/RT × 2(1 − α)[−ln(1 − α)]1/2, where α is conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901950y Exemplaires
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Titre : Prediction of activated carbon injection performance for mercury capture in a full-scale coal-fired boiler Type de document : texte imprimé Auteurs : Wei Zhou, Auteur ; Gilles Eggenspieler, Auteur ; Abu Rokanuzzaman, Auteur Année de publication : 2010 Article en page(s) : pp. 3603–3610 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Prediction Activated Carbon Injection Mercury Coal-Fired Résumé : Activated carbon injection (ACI) is an effective mercury control technology demonstrated in both short-term and long-term full-scale tests. The effectiveness of mercury capture by activated carbon depends on the mercury speciation, total mercury concentration, flue gas composition, method of capture, and activated carbon properties, such as pore size, type of carbon impregnation, and surface area, etc. It is also desired that an ACI system be designed to produce good mixing between the activated carbon and the flue gas.
In recent years, General Electric Energy has conducted both short-term and long-term tests in large-scale coal-fired boilers for ACI mercury capture demonstration. The programs consisted of (1) combustion optimization to improve natural mercury capture by fly ash, (2) computational fluid dynamics (CFD) modeling of activated carbon injection to design ACI lances, (3) a short-term test to select the activated carbon type, and (4) a long-term test to evaluate the mercury capture performance. This paper presents the CFD modeling for an ACI demonstration in Sundance Station Unit 5. The CFD model developed describes the film mass transport, pore diffusion, and carbon surface adsorption and desorption phenomena for the prediction of the mercury capture rate. The model was applied to evaluate the lance design and to calculate the mercury capture rate. The test data were also presented for comparison with the model results.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901967p
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3603–3610[article] Prediction of activated carbon injection performance for mercury capture in a full-scale coal-fired boiler [texte imprimé] / Wei Zhou, Auteur ; Gilles Eggenspieler, Auteur ; Abu Rokanuzzaman, Auteur . - 2010 . - pp. 3603–3610.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3603–3610
Mots-clés : Prediction Activated Carbon Injection Mercury Coal-Fired Résumé : Activated carbon injection (ACI) is an effective mercury control technology demonstrated in both short-term and long-term full-scale tests. The effectiveness of mercury capture by activated carbon depends on the mercury speciation, total mercury concentration, flue gas composition, method of capture, and activated carbon properties, such as pore size, type of carbon impregnation, and surface area, etc. It is also desired that an ACI system be designed to produce good mixing between the activated carbon and the flue gas.
In recent years, General Electric Energy has conducted both short-term and long-term tests in large-scale coal-fired boilers for ACI mercury capture demonstration. The programs consisted of (1) combustion optimization to improve natural mercury capture by fly ash, (2) computational fluid dynamics (CFD) modeling of activated carbon injection to design ACI lances, (3) a short-term test to select the activated carbon type, and (4) a long-term test to evaluate the mercury capture performance. This paper presents the CFD modeling for an ACI demonstration in Sundance Station Unit 5. The CFD model developed describes the film mass transport, pore diffusion, and carbon surface adsorption and desorption phenomena for the prediction of the mercury capture rate. The model was applied to evaluate the lance design and to calculate the mercury capture rate. The test data were also presented for comparison with the model results.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901967p Exemplaires
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Titre : “ Petroleum gas oil-ethanol ” blends used as feeds : increased production of ethylene and propylene over catalytic steam-cracking (CSC) hybrid catalysts. different behavior of methanol in blends with petroleum gas oil Type de document : texte imprimé Auteurs : A. Muntasar, Auteur ; R. Le Van Mao, Auteur ; H. T. Yan, Auteur Année de publication : 2010 Article en page(s) : pp. 3611–3616 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Petroleum Gas Oil− Ethanol Feeds Ethylene Propylene Steam-Cracking Hybrid Catalysts Methanol Oil Résumé : Hybrid catalysts that contain Zn−Pd-based cocatalyst show a higher and more positive sensitivity to ethanol than catalysts that contain supported Ni−Ru cocatalyst. In fact, with the former catalysts, the use of “gas oil−ethanol” blends significantly increases the product yields of light olefins and particularly ethylene. This appears to be actually a good approach for the partial replacement of petroleum feedstocks by bioderived chemicals (particularly, bioethanol). Another advantage of the CSC process is that it can make use of simply concentrated ethanol in aqueous solution as obtained by enzymatic conversion of biomass. This is maybe the first example of the beneficial effect of bioethanol on the performance of the CSC catalysts, suggesting that the integration of a small “biorefinery” to a petrochemical production plant is now possible. On the other hand, over our hybrid catalysts methanol used as coreactant behaves very differently from ethanol. In fact, while ethanol undergoes predominantly dehydration into ethylene, methanol predominantly intervenes directly in the hydrocarbon pool, keeping the product propylene-to-ethylene ratio almost constant and higher than 1.5. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902035m
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3611–3616[article] “ Petroleum gas oil-ethanol ” blends used as feeds : increased production of ethylene and propylene over catalytic steam-cracking (CSC) hybrid catalysts. different behavior of methanol in blends with petroleum gas oil [texte imprimé] / A. Muntasar, Auteur ; R. Le Van Mao, Auteur ; H. T. Yan, Auteur . - 2010 . - pp. 3611–3616.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3611–3616
Mots-clés : Petroleum Gas Oil− Ethanol Feeds Ethylene Propylene Steam-Cracking Hybrid Catalysts Methanol Oil Résumé : Hybrid catalysts that contain Zn−Pd-based cocatalyst show a higher and more positive sensitivity to ethanol than catalysts that contain supported Ni−Ru cocatalyst. In fact, with the former catalysts, the use of “gas oil−ethanol” blends significantly increases the product yields of light olefins and particularly ethylene. This appears to be actually a good approach for the partial replacement of petroleum feedstocks by bioderived chemicals (particularly, bioethanol). Another advantage of the CSC process is that it can make use of simply concentrated ethanol in aqueous solution as obtained by enzymatic conversion of biomass. This is maybe the first example of the beneficial effect of bioethanol on the performance of the CSC catalysts, suggesting that the integration of a small “biorefinery” to a petrochemical production plant is now possible. On the other hand, over our hybrid catalysts methanol used as coreactant behaves very differently from ethanol. In fact, while ethanol undergoes predominantly dehydration into ethylene, methanol predominantly intervenes directly in the hydrocarbon pool, keeping the product propylene-to-ethylene ratio almost constant and higher than 1.5. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902035m Exemplaires
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Titre : Development of a photocatalytic wet scrubbing process for gaseous odor treatment Type de document : texte imprimé Auteurs : Tong-xu Liu, Auteur ; Xiang-Song Li, Auteur ; Fang-bai Li, Auteur Année de publication : 2010 Article en page(s) : pp.3617–3622 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic Wet Scrubbing Gaseous Odor Résumé : In this study, methyl mercaptan (CH3SH) gas was used to prepare synthetic odorous gases, and a photocatalytic wet scrubbing process as a new approach was developed for treating such odorous gases. In this process, gaseous CH3SH is first absorbed by the solution, and the dissolved CH3SH/CH3S− is then adsorbed onto the solid surface of TiO2 particles and oxidized under UV illumination in the aqueous phase. Experiments were conducted under different reaction conditions of CH3SH loading, TiO2 dosage, and pH. The reaction kinetics of CH3SH reduction indicates that the pH of the reaction solution greatly influences the rate of CH3SH absorption by the solution. At pH 11.5, the photoreaction becomes the RDS in such a system. The experiments demonstrated that the efficiency of CH3SH degradation determined by two methyl mercaptan sensors and the ratio of odor removal determined by olfactometry measurements can be well maintained at high levels of >95% for a CH3SH loading of 10 g m−3 h−1. The main intermediates and final products from CH3SH degradation were identified by GC/MS and ion chromatography, and a pathway for CH3SH degradation with three routes is proposed and discussed. Odor samples to simulate real foul gases were also prepared and treated with this new process. An electronic nose technique was applied to indentify the patterns of odor characteristics before and after treatment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000295?prevSearch=Development%2Bof%2Ba%2B [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp.3617–3622[article] Development of a photocatalytic wet scrubbing process for gaseous odor treatment [texte imprimé] / Tong-xu Liu, Auteur ; Xiang-Song Li, Auteur ; Fang-bai Li, Auteur . - 2010 . - pp.3617–3622.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp.3617–3622
Mots-clés : Photocatalytic Wet Scrubbing Gaseous Odor Résumé : In this study, methyl mercaptan (CH3SH) gas was used to prepare synthetic odorous gases, and a photocatalytic wet scrubbing process as a new approach was developed for treating such odorous gases. In this process, gaseous CH3SH is first absorbed by the solution, and the dissolved CH3SH/CH3S− is then adsorbed onto the solid surface of TiO2 particles and oxidized under UV illumination in the aqueous phase. Experiments were conducted under different reaction conditions of CH3SH loading, TiO2 dosage, and pH. The reaction kinetics of CH3SH reduction indicates that the pH of the reaction solution greatly influences the rate of CH3SH absorption by the solution. At pH 11.5, the photoreaction becomes the RDS in such a system. The experiments demonstrated that the efficiency of CH3SH degradation determined by two methyl mercaptan sensors and the ratio of odor removal determined by olfactometry measurements can be well maintained at high levels of >95% for a CH3SH loading of 10 g m−3 h−1. The main intermediates and final products from CH3SH degradation were identified by GC/MS and ion chromatography, and a pathway for CH3SH degradation with three routes is proposed and discussed. Odor samples to simulate real foul gases were also prepared and treated with this new process. An electronic nose technique was applied to indentify the patterns of odor characteristics before and after treatment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000295?prevSearch=Development%2Bof%2Ba%2B [...] Exemplaires
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Titre : Varying gravity force using magnetic-field emulated artificial gravity: application to cocurrent gas−liquid flows in porous media Type de document : texte imprimé Auteurs : F. Larachi, Auteur ; M. C. Munteanu, Auteur Année de publication : 2010 Article en page(s) : pp. 3623–3633 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Gravity Force Artificial Gas− Liquid Flows Media Résumé : A method was proposed to investigate the effects of modifying, via magnetic fields, both modules and directions of the net gravitational body forces of gas and liquid and to follow their incidence on the evolution of pressure drop, wetting efficiency, and liquid holdup in cocurrent gas−liquid downflow and upflow fixed beds. New pseudogravity cases arose and were rationalized in terms of driving or resisting forces in two-phase flows. The method was based on applying on nonmagnetic (paramagnetic and diamagnetic) fluids strong static inhomogeneous magnetic fields generated in the vertical atmospheric bore of a superconducting magnet. Depending on the signs of the magnetic susceptibility and of the gradient of magnetic induction, the gas or liquid was subjected to macrogravity, microgravity, and retrogravity. Gas and liquid in microgravity, gas in macrogravity and liquid in microgravity, gas in retrogravity and liquid in macrogravity, and gas and liquid in retrogravity were the combinations studied. The variations of pressure drop, liquid holdup, and wetting efficiency were rationalized by distinguishing the conditions whereby the total apparent fluids’ weight under the magnetic field was either acting as a driving or as a resisting force. Liquid holdups in cocurrent downflow were found to decrease in retrogravity and increase in microgravity and macrogravity, whereas in upflow liquid holdups increased regardless of the prevailing artificial gravity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100039k?prevSearch=Varying%2Bgravity%2Bfor [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3623–3633[article] Varying gravity force using magnetic-field emulated artificial gravity: application to cocurrent gas−liquid flows in porous media [texte imprimé] / F. Larachi, Auteur ; M. C. Munteanu, Auteur . - 2010 . - pp. 3623–3633.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3623–3633
Mots-clés : Gravity Force Artificial Gas− Liquid Flows Media Résumé : A method was proposed to investigate the effects of modifying, via magnetic fields, both modules and directions of the net gravitational body forces of gas and liquid and to follow their incidence on the evolution of pressure drop, wetting efficiency, and liquid holdup in cocurrent gas−liquid downflow and upflow fixed beds. New pseudogravity cases arose and were rationalized in terms of driving or resisting forces in two-phase flows. The method was based on applying on nonmagnetic (paramagnetic and diamagnetic) fluids strong static inhomogeneous magnetic fields generated in the vertical atmospheric bore of a superconducting magnet. Depending on the signs of the magnetic susceptibility and of the gradient of magnetic induction, the gas or liquid was subjected to macrogravity, microgravity, and retrogravity. Gas and liquid in microgravity, gas in macrogravity and liquid in microgravity, gas in retrogravity and liquid in macrogravity, and gas and liquid in retrogravity were the combinations studied. The variations of pressure drop, liquid holdup, and wetting efficiency were rationalized by distinguishing the conditions whereby the total apparent fluids’ weight under the magnetic field was either acting as a driving or as a resisting force. Liquid holdups in cocurrent downflow were found to decrease in retrogravity and increase in microgravity and macrogravity, whereas in upflow liquid holdups increased regardless of the prevailing artificial gravity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100039k?prevSearch=Varying%2Bgravity%2Bfor [...] Exemplaires
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Titre : Hydrogen storage properties of low--silica type X zeolites Type de document : texte imprimé Auteurs : Lifeng Wang, Auteur ; Ralph T. Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 3634–3641 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Hydrogen Silica Zeolites Résumé : Hydrogen adsorption properties of low-silica type X zeolites (LSX, Si/Al = 1) containing alkali or alkali-earth metal cations (Li+, Ca2+, and Mg2+) have been studied. It was found that the hydrogen adsorption capacities of LSX zeolites at 77 K were determined mainly by the porosity of the zeolite, while at 298 K, the storage capacities depended on both the H2−cation interactions and the porosity. Among the three exchanged zeolites, Li-LSX had the highest H2 capacity of 1.5 wt % at 77 K and 1 atm, and Ca-LSX had the highest capacity of 0.50 wt % at 298 K and 10 MPa. The hydrogen storage in LSX zeolites via spillover was also investigated. Three methods including bridge building with a catalyst, metal doping via incipient wetness impregnation and metal doping via chemical vapor deposition (CVD) were employed to induce hydrogen spillover, and enhance the storage capacities. Thus, the storage capacities were increased to 0.96−1.2 wt % on the Pt-doped zeolites at 298 K and 10 MPa. The differences between the three methods were compared and discussed. Furthermore, 5 and 10 wt % Ni were doped on Ca-LSX zeolite. The 10 wt % Ni-doped Ca-LSX zeolite showed a storage capacity of 1.15 wt % at 100 atm and 298 K. The important volumetric storage capacities of these zeolites were also estimated based on the densities of the densified zeolites. A 21 g/L portion was obtained for Pt-doped Ca-LSX, and 20 g/L was obtained for Ni-doped Ca-LSX, both at 298 K and 10 MPa. The high volumetric capacities were obtained because of the high densities of zeolites which are substantially higher (2−3 times higher) than that of carbons and metal−organic frameworks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003152?prevSearch=Hydrogen%2Bstorage%2Bpr [...]
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3634–3641[article] Hydrogen storage properties of low--silica type X zeolites [texte imprimé] / Lifeng Wang, Auteur ; Ralph T. Yang, Auteur . - 2010 . - pp. 3634–3641.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3634–3641
Mots-clés : Hydrogen Silica Zeolites Résumé : Hydrogen adsorption properties of low-silica type X zeolites (LSX, Si/Al = 1) containing alkali or alkali-earth metal cations (Li+, Ca2+, and Mg2+) have been studied. It was found that the hydrogen adsorption capacities of LSX zeolites at 77 K were determined mainly by the porosity of the zeolite, while at 298 K, the storage capacities depended on both the H2−cation interactions and the porosity. Among the three exchanged zeolites, Li-LSX had the highest H2 capacity of 1.5 wt % at 77 K and 1 atm, and Ca-LSX had the highest capacity of 0.50 wt % at 298 K and 10 MPa. The hydrogen storage in LSX zeolites via spillover was also investigated. Three methods including bridge building with a catalyst, metal doping via incipient wetness impregnation and metal doping via chemical vapor deposition (CVD) were employed to induce hydrogen spillover, and enhance the storage capacities. Thus, the storage capacities were increased to 0.96−1.2 wt % on the Pt-doped zeolites at 298 K and 10 MPa. The differences between the three methods were compared and discussed. Furthermore, 5 and 10 wt % Ni were doped on Ca-LSX zeolite. The 10 wt % Ni-doped Ca-LSX zeolite showed a storage capacity of 1.15 wt % at 100 atm and 298 K. The important volumetric storage capacities of these zeolites were also estimated based on the densities of the densified zeolites. A 21 g/L portion was obtained for Pt-doped Ca-LSX, and 20 g/L was obtained for Ni-doped Ca-LSX, both at 298 K and 10 MPa. The high volumetric capacities were obtained because of the high densities of zeolites which are substantially higher (2−3 times higher) than that of carbons and metal−organic frameworks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003152?prevSearch=Hydrogen%2Bstorage%2Bpr [...] Exemplaires
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Titre : Microencapsulation of epoxidized linseed oil liquid cross-linker in poly(N-vinyl-pyrrolidone) : optimization by a design-of-experiments approach Type de document : texte imprimé Auteurs : Daniela Senatore, Auteur ; Jozua Laven, Auteur ; Rolf A. T. M. van Benthem, Auteur Année de publication : 2010 Article en page(s) : pp. 3642–3653 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Microencapsulation Epoxidized Linseed Oil Liquid Poly N-vinyl-pyrrolidone Résumé : A liquid cross-linker, epoxidized linseed oil (ELO), was encapsulated in a plastic with a high glass transition temperature (poly(N-vinyl-2-pyrrolidone); PVP). The process parameters of the spray-drying employed were optimized by a Design-of-Experiments (DoE) approach. Three factors concerning both the dispersion feed (total concentration of additive and core to encapsulant ratio) and the spray-drying processes (spray flow of the spray-drier) were chosen. A full 23 factorial Design of Experiments with center point was carried out in duplicate. The aim of the Design of Experiments was to understand and to optimize the encapsulation process in terms of total amount of epoxidized linseed oil in the powder (payload) and amount of epoxidized linseed oil enclosed in the polyvinylpyrrolidone (encapsulation efficiency). The results enabled the production of a free-flowing spray-dried powder of ELO encapsulated in PVP with an encapsulation efficiency of 85%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900919g
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3642–3653[article] Microencapsulation of epoxidized linseed oil liquid cross-linker in poly(N-vinyl-pyrrolidone) : optimization by a design-of-experiments approach [texte imprimé] / Daniela Senatore, Auteur ; Jozua Laven, Auteur ; Rolf A. T. M. van Benthem, Auteur . - 2010 . - pp. 3642–3653.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3642–3653
Mots-clés : Microencapsulation Epoxidized Linseed Oil Liquid Poly N-vinyl-pyrrolidone Résumé : A liquid cross-linker, epoxidized linseed oil (ELO), was encapsulated in a plastic with a high glass transition temperature (poly(N-vinyl-2-pyrrolidone); PVP). The process parameters of the spray-drying employed were optimized by a Design-of-Experiments (DoE) approach. Three factors concerning both the dispersion feed (total concentration of additive and core to encapsulant ratio) and the spray-drying processes (spray flow of the spray-drier) were chosen. A full 23 factorial Design of Experiments with center point was carried out in duplicate. The aim of the Design of Experiments was to understand and to optimize the encapsulation process in terms of total amount of epoxidized linseed oil in the powder (payload) and amount of epoxidized linseed oil enclosed in the polyvinylpyrrolidone (encapsulation efficiency). The results enabled the production of a free-flowing spray-dried powder of ELO encapsulated in PVP with an encapsulation efficiency of 85%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900919g Exemplaires
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Titre : Self-cleaning films with high transparency based on tiO2 nanoparticles synthesized via flame combustion Type de document : texte imprimé Auteurs : Huiting Wang, Auteur ; Yanjie Hu, Auteur ; Ling Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 3654–3662 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Self-Cleaning Films with High Transparency Nanoparticles Synthesized Flame Combustion Résumé : Self-cleaning transparent nanoporous films with high photocatalytic properties were obtained based on the self-assembly of TiO2 nanoparticles synthesized by H2/O2 combustion flames. Films were prepared from multilayer deposition of poly(sodium 4-styrenesulfonate)-treated TiO2 nanoparticles and SiO2 nanoparticles with electrostatic interaction by the adsorption of positively charged poly(diallyldimethylammonium chloride) via layer-by-layer assembly processes. The assembly conditions, such as the pH and concentration of a nanoparticle suspension that cause variation of the surface charge densities, were found to strongly affect the thickness and morphology of multilayer films. TiO2/SiO2 coatings assembled with 10 cycles reach effective photocatalysis with a maximum transmittance of 99.3% as well as a water droplet spreading time as short as 0.29 s. The photodegradation kinetics showed that multilayer films fabricated with 10 cycles are 4 times more active than films assembled with 5 cycles, indicating that flame-synthesized TiO2 with well crystallinity can be used to fabricate high transparent self-cleaning films at suitable assembly conditions. The photocatalytic degradation kinetics dominated by control of the number of assembled cycles was also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901782w
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3654–3662[article] Self-cleaning films with high transparency based on tiO2 nanoparticles synthesized via flame combustion [texte imprimé] / Huiting Wang, Auteur ; Yanjie Hu, Auteur ; Ling Zhang, Auteur . - 2010 . - pp. 3654–3662.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3654–3662
Mots-clés : Self-Cleaning Films with High Transparency Nanoparticles Synthesized Flame Combustion Résumé : Self-cleaning transparent nanoporous films with high photocatalytic properties were obtained based on the self-assembly of TiO2 nanoparticles synthesized by H2/O2 combustion flames. Films were prepared from multilayer deposition of poly(sodium 4-styrenesulfonate)-treated TiO2 nanoparticles and SiO2 nanoparticles with electrostatic interaction by the adsorption of positively charged poly(diallyldimethylammonium chloride) via layer-by-layer assembly processes. The assembly conditions, such as the pH and concentration of a nanoparticle suspension that cause variation of the surface charge densities, were found to strongly affect the thickness and morphology of multilayer films. TiO2/SiO2 coatings assembled with 10 cycles reach effective photocatalysis with a maximum transmittance of 99.3% as well as a water droplet spreading time as short as 0.29 s. The photodegradation kinetics showed that multilayer films fabricated with 10 cycles are 4 times more active than films assembled with 5 cycles, indicating that flame-synthesized TiO2 with well crystallinity can be used to fabricate high transparent self-cleaning films at suitable assembly conditions. The photocatalytic degradation kinetics dominated by control of the number of assembled cycles was also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901782w Exemplaires
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Titre : Adsorption of CO2 on hydrotalcite-derived mixed oxides : sorption mechanisms and consequences for adsorption irreversibility Type de document : texte imprimé Auteurs : Marta León, Auteur ; Eva Díaz, Auteur ; Simona Bennici, Auteur Année de publication : 2010 Article en page(s) : pp. 3663–3671 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Adsorption CO2 Hydrotalcite Oxides Sorption Mechanisms Consequences Résumé : Magnesium−aluminum double oxides derived from the thermal treatment of layered hydroxides (hydrotalcites) have been tested for CO2 adsorption. The effects of various preparation parameters, such as the incorporated cation (K or Na), the mode of addition of magnesium and aluminum precursors, the presence of sonication, and the calcination temperature, on the adsorption capacity under mild conditions were studied using thermogravimetry and calorimetry. Calorimetric and FTIR data were used to explain the adsorption mechanisms leading to the undesirable irreversible adsorption. This adsorption was related to the formation of unidentate CO2-adsorbent species with the strongest adsorption sites, whereas bidentate and surface bicarbonates lead to highly reversible adsorption. In conclusion, preparation procedures that lead to an increase in the strength of basic sites do not lead to significant increases in the adsorption capacity, but rather lead to more difficult regeneration of the saturated support. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902072a
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3663–3671[article] Adsorption of CO2 on hydrotalcite-derived mixed oxides : sorption mechanisms and consequences for adsorption irreversibility [texte imprimé] / Marta León, Auteur ; Eva Díaz, Auteur ; Simona Bennici, Auteur . - 2010 . - pp. 3663–3671.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3663–3671
Mots-clés : Adsorption CO2 Hydrotalcite Oxides Sorption Mechanisms Consequences Résumé : Magnesium−aluminum double oxides derived from the thermal treatment of layered hydroxides (hydrotalcites) have been tested for CO2 adsorption. The effects of various preparation parameters, such as the incorporated cation (K or Na), the mode of addition of magnesium and aluminum precursors, the presence of sonication, and the calcination temperature, on the adsorption capacity under mild conditions were studied using thermogravimetry and calorimetry. Calorimetric and FTIR data were used to explain the adsorption mechanisms leading to the undesirable irreversible adsorption. This adsorption was related to the formation of unidentate CO2-adsorbent species with the strongest adsorption sites, whereas bidentate and surface bicarbonates lead to highly reversible adsorption. In conclusion, preparation procedures that lead to an increase in the strength of basic sites do not lead to significant increases in the adsorption capacity, but rather lead to more difficult regeneration of the saturated support. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902072a Exemplaires
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Titre : Extractive dividing wall column : design and optimization Type de document : texte imprimé Auteurs : Christian Bravo-Jonard, Auteur ; Juan Gabriel Segovia-Hernandez, Auteur ; Claudia Gutiérrez-Antonio, Auteur Année de publication : 2010 Article en page(s) : pp. 3672–3688 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : extractive wall multiobjective genetic algorithms distillation process. Résumé : This paper proposes a novel extractive dividing wall distillation column, which has been designed using a constrained stochastic multiobjective optimization technique. The approach is based on the use of genetic algorithms to determine the design that minimizes energy consumption and total annualized cost. Several case studies are used to show the feasibility of performing extractive separations in dividing wall distillation columns. The simulation results show the effect of the main variables on the complex extractive distillation process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9006936
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3672–3688[article] Extractive dividing wall column : design and optimization [texte imprimé] / Christian Bravo-Jonard, Auteur ; Juan Gabriel Segovia-Hernandez, Auteur ; Claudia Gutiérrez-Antonio, Auteur . - 2010 . - pp. 3672–3688.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3672–3688
Mots-clés : extractive wall multiobjective genetic algorithms distillation process. Résumé : This paper proposes a novel extractive dividing wall distillation column, which has been designed using a constrained stochastic multiobjective optimization technique. The approach is based on the use of genetic algorithms to determine the design that minimizes energy consumption and total annualized cost. Several case studies are used to show the feasibility of performing extractive separations in dividing wall distillation columns. The simulation results show the effect of the main variables on the complex extractive distillation process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9006936 Exemplaires
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Titre : Bilevel optimizing control structure for a simulated moving bed process based on a reduced-order model using the cubic spline collocation method Type de document : texte imprimé Auteurs : Kiwoong Kim, Auteur ; Kwang Soon Lee, Auteur ; Jay H. Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 3689–3699 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Bilevel Moving Bed Résumé : A bilevel strategy for optimizing control of a simulated moving bed (SMB) process is proposed. In the lower level, repetitive model predictive control (RMPC) is used to regulate product purities; in the upper level, optimal feed/desorbent flow rates and the switching period are determined. Both levels employ a fundamental SMB model reduced to a set of nonlinear discrete-time dynamic equations using the cubic spline collocation method and exact discretization. For RMPC, the SMB model is linearized successively along the operating trajectories seen in the previous switching period. It is assumed that the flow rates can be varied within a switching period and the average product purities over each switching period can be measured albeit with a significant analysis delay. Numerical studies using linear isotherms showed that the proposed strategy is successful at driving the process to the intended optimum and maintaining it there while robustly regulating the product purities despite various uncertainties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901121y
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3689–3699[article] Bilevel optimizing control structure for a simulated moving bed process based on a reduced-order model using the cubic spline collocation method [texte imprimé] / Kiwoong Kim, Auteur ; Kwang Soon Lee, Auteur ; Jay H. Lee, Auteur . - 2010 . - pp. 3689–3699.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3689–3699
Mots-clés : Bilevel Moving Bed Résumé : A bilevel strategy for optimizing control of a simulated moving bed (SMB) process is proposed. In the lower level, repetitive model predictive control (RMPC) is used to regulate product purities; in the upper level, optimal feed/desorbent flow rates and the switching period are determined. Both levels employ a fundamental SMB model reduced to a set of nonlinear discrete-time dynamic equations using the cubic spline collocation method and exact discretization. For RMPC, the SMB model is linearized successively along the operating trajectories seen in the previous switching period. It is assumed that the flow rates can be varied within a switching period and the average product purities over each switching period can be measured albeit with a significant analysis delay. Numerical studies using linear isotherms showed that the proposed strategy is successful at driving the process to the intended optimum and maintaining it there while robustly regulating the product purities despite various uncertainties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901121y Exemplaires
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Titre : Operational performance assessment and fault isolation for multimode processes Type de document : texte imprimé Auteurs : Jialin Liu, Auteur ; Ding-Sou Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 3700–3714 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Operational Performance Assessment Fault Isolation Multimode Processes Résumé : Industrial processes are usually operated under normal conditions during daily production. For the purpose of improving product quality and productivity, the process engineers need to realize where the process variations come from. In this paper, according to the geometric shapes of clusters on the principal component (PC) subspace, the major variations along variable directions can be identified using a Pareto diagram and the 80/20 rule. In addition, fault isolation charts on the PC subspace are proposed to locate faulty variables when detecting abnormal events. A simulation example is demonstrated where the proposed approach is capable of locating the faulty variables without a smearing effect even in the case of multiple sensor faults. An industrial application of assessing operational performance and isolating faulty variables is presented. The results show that the faulty variables are highly correlated to the variables dominating the data variations in the normal operations, i.e., process-related abnormalities can be prevented by reducing the process variations during normal operations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901634r
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3700–3714[article] Operational performance assessment and fault isolation for multimode processes [texte imprimé] / Jialin Liu, Auteur ; Ding-Sou Chen, Auteur . - 2010 . - pp. 3700–3714.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3700–3714
Mots-clés : Operational Performance Assessment Fault Isolation Multimode Processes Résumé : Industrial processes are usually operated under normal conditions during daily production. For the purpose of improving product quality and productivity, the process engineers need to realize where the process variations come from. In this paper, according to the geometric shapes of clusters on the principal component (PC) subspace, the major variations along variable directions can be identified using a Pareto diagram and the 80/20 rule. In addition, fault isolation charts on the PC subspace are proposed to locate faulty variables when detecting abnormal events. A simulation example is demonstrated where the proposed approach is capable of locating the faulty variables without a smearing effect even in the case of multiple sensor faults. An industrial application of assessing operational performance and isolating faulty variables is presented. The results show that the faulty variables are highly correlated to the variables dominating the data variations in the normal operations, i.e., process-related abnormalities can be prevented by reducing the process variations during normal operations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901634r Exemplaires
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Titre : Optimization of total networks of water-using and treatment units by genetic algorithms Type de document : texte imprimé Auteurs : Raluca Tudor, Auteur ; Vasile Lavric, Auteur Année de publication : 2010 Article en page(s) : pp. 3715–3731 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Networks Water Treatment Genetic Algorithms Résumé : The optimization of an integrated network of water-using (WU) and treatment (TU) units is addressed in this paper, by targeting for maximum treated water reuse as a considerably better alternative to fresh water consumption. An optimal integrated water network (WN) is an oriented graph, starting with inlet contaminant free WUs and then the other WUs ranked by a certain criteria. The outlet wastewater streams are either split to be reused by the next WUs in sequence or sent to treatment. The mathematical model of the integrated WN is based upon total and contaminant species mass balances for each and every WU/TU which is restricted with respect to the inlet and outlet contaminant concentrations. The performance of the approach is tested on a synthetic example. Several scenarios were used, the results being analyzed in connection with the reduction of fresh water consumption and the increase of internal and treated water reuse. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901687z
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3715–3731[article] Optimization of total networks of water-using and treatment units by genetic algorithms [texte imprimé] / Raluca Tudor, Auteur ; Vasile Lavric, Auteur . - 2010 . - pp. 3715–3731.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3715–3731
Mots-clés : Networks Water Treatment Genetic Algorithms Résumé : The optimization of an integrated network of water-using (WU) and treatment (TU) units is addressed in this paper, by targeting for maximum treated water reuse as a considerably better alternative to fresh water consumption. An optimal integrated water network (WN) is an oriented graph, starting with inlet contaminant free WUs and then the other WUs ranked by a certain criteria. The outlet wastewater streams are either split to be reused by the next WUs in sequence or sent to treatment. The mathematical model of the integrated WN is based upon total and contaminant species mass balances for each and every WU/TU which is restricted with respect to the inlet and outlet contaminant concentrations. The performance of the approach is tested on a synthetic example. Several scenarios were used, the results being analyzed in connection with the reduction of fresh water consumption and the increase of internal and treated water reuse. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901687z Exemplaires
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Titre : Gas pressure drop and mass transfer characteristics in a cross-flow rotating packed bed with porous plate packing Type de document : texte imprimé Auteurs : Wei Zhou Jiao, Auteur ; You Zhi Liu, Auteur ; Gui Sheng Qi, Auteur Année de publication : 2010 Article en page(s) : pp. 3732–3740 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Gas Pressure Drop Cross-flow Porous Plate Packing Résumé : Structured packing were proposed and designed according to gas−liquid mass transfer and kinetic balance characteristics in a cross-flow rotating packed bed (RPB). Two types of novel porous plate packing were investigated respectively in a cross-flow RPB to examine their gas pressure drop and mass transfer characteristics with CO2−NaOH solution system. Compared with the literature, the pressure drop of the cross-flow rotating packed bed with new structured packing was slower than that of wire-gauze packing and was no more than a tenth that of the countercurrent rotating packed bed in the same operational condition. The volume mass transfer coefficient of RPB with new structured packing was higher than that with wire-gauze packing, which was higher than that of countercurrent RPB and was 1−2 orders of magnitude higher than that of the conventional packed tower. Moreover, the correlative expressions of gas pressure drop and volume mass transfer coefficients of RPB were obtained using the MATLAB program and in good agreement with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009777
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3732–3740[article] Gas pressure drop and mass transfer characteristics in a cross-flow rotating packed bed with porous plate packing [texte imprimé] / Wei Zhou Jiao, Auteur ; You Zhi Liu, Auteur ; Gui Sheng Qi, Auteur . - 2010 . - pp. 3732–3740.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3732–3740
Mots-clés : Gas Pressure Drop Cross-flow Porous Plate Packing Résumé : Structured packing were proposed and designed according to gas−liquid mass transfer and kinetic balance characteristics in a cross-flow rotating packed bed (RPB). Two types of novel porous plate packing were investigated respectively in a cross-flow RPB to examine their gas pressure drop and mass transfer characteristics with CO2−NaOH solution system. Compared with the literature, the pressure drop of the cross-flow rotating packed bed with new structured packing was slower than that of wire-gauze packing and was no more than a tenth that of the countercurrent rotating packed bed in the same operational condition. The volume mass transfer coefficient of RPB with new structured packing was higher than that with wire-gauze packing, which was higher than that of countercurrent RPB and was 1−2 orders of magnitude higher than that of the conventional packed tower. Moreover, the correlative expressions of gas pressure drop and volume mass transfer coefficients of RPB were obtained using the MATLAB program and in good agreement with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009777 Exemplaires
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Titre : Ion-exchange processing of fermentation media containing lactic acid and oligomeric saccharides Type de document : texte imprimé Auteurs : Beatriz Gullón, Auteur ; Jose Luis Alonso, Auteur ; J. C. Parajó, Auteur Année de publication : 2010 Article en page(s) : pp. 3741–3750 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Ion-Exchange Fermentation Lactic Acid Oligomeric Saccharides Résumé : Ion-exchange processing was employed to separate oligomers and lactic acid (LA) present in fermentation broths derived from apple pomace supplemented with yeast extract (YE) or corn steep liquor (CSL) using Lactobacillus rhamnosus. Experiments were carried out with Amberlite IRA 96 or Amberlite IRA 400 anion-exchange resins. Fermentation media supplemented with YE enabled higher oligosaccharide recovery yields than CSL-supplemented ones, whereas Amberlite IRA 96 provided a better separation of oligomers and LA than Amberlite IRA 400. Starting from a YE-supplemented fermentation medium containing 60.5 g of LA/L and 33.9 g of oligomers/L, column separation with Amberlite IRA 96 led to an effluent during the loading stage, which contained 17.9 g of oligosaccharides/L with an oligosaccharide/LA mass ratio of 90/10 g/g, whereas the regeneration stage provided a solution containing 30 g of LA/L with a oligosaccharide/LA mass ratio of 8/92 g/g. Material balances showed that the regeneration effluent contained about 55% of the LA present in the feed stream, whereas only 2.1% was eluted jointly with oligomers during the loading phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901397k
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3741–3750[article] Ion-exchange processing of fermentation media containing lactic acid and oligomeric saccharides [texte imprimé] / Beatriz Gullón, Auteur ; Jose Luis Alonso, Auteur ; J. C. Parajó, Auteur . - 2010 . - pp. 3741–3750.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3741–3750
Mots-clés : Ion-Exchange Fermentation Lactic Acid Oligomeric Saccharides Résumé : Ion-exchange processing was employed to separate oligomers and lactic acid (LA) present in fermentation broths derived from apple pomace supplemented with yeast extract (YE) or corn steep liquor (CSL) using Lactobacillus rhamnosus. Experiments were carried out with Amberlite IRA 96 or Amberlite IRA 400 anion-exchange resins. Fermentation media supplemented with YE enabled higher oligosaccharide recovery yields than CSL-supplemented ones, whereas Amberlite IRA 96 provided a better separation of oligomers and LA than Amberlite IRA 400. Starting from a YE-supplemented fermentation medium containing 60.5 g of LA/L and 33.9 g of oligomers/L, column separation with Amberlite IRA 96 led to an effluent during the loading stage, which contained 17.9 g of oligosaccharides/L with an oligosaccharide/LA mass ratio of 90/10 g/g, whereas the regeneration stage provided a solution containing 30 g of LA/L with a oligosaccharide/LA mass ratio of 8/92 g/g. Material balances showed that the regeneration effluent contained about 55% of the LA present in the feed stream, whereas only 2.1% was eluted jointly with oligomers during the loading phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901397k Exemplaires
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Titre : Absorber model for CO2 capture by monoethanolamine Type de document : texte imprimé Auteurs : Leila Faramarzi, Auteur ; Georgios M. Kontogeorgis, Auteur ; Michael L. Michelsen, Auteur Année de publication : 2010 Article en page(s) : pp. 3751–3759 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Absorber Model CO2 Capture Monoethanolamine Résumé : The rate-based steady-state model proposed by Gabrielsen et al. (Gabrielsen, J.; Michelsen, M. L.; Kontogeorgis, G. M.; Stenby, E. H. AIChE J. 2006, 52, 10, 3443−3451) for the design of the CO2−2-amino-2-methyl-propanol absorbers is adopted and improved for the design of the CO2−monoethanolamine absorber. The influence of the application of different mass transfer correlations on the model’s performance is investigated. Analytical expressions for the calculation of the enhancement factor for the second order as well as the pseudo-first-order reaction regime are integrated in the model, and their impact on the model’s prediction is compared. The model has been successfully applied to CO2 absorber packed columns and validated against pilot plant data with good agreement. ISSN : 0888-5885 En ligne : Absorber Model for CO2 Capture by Monoethanolamine
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3751–3759[article] Absorber model for CO2 capture by monoethanolamine [texte imprimé] / Leila Faramarzi, Auteur ; Georgios M. Kontogeorgis, Auteur ; Michael L. Michelsen, Auteur . - 2010 . - pp. 3751–3759.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3751–3759
Mots-clés : Absorber Model CO2 Capture Monoethanolamine Résumé : The rate-based steady-state model proposed by Gabrielsen et al. (Gabrielsen, J.; Michelsen, M. L.; Kontogeorgis, G. M.; Stenby, E. H. AIChE J. 2006, 52, 10, 3443−3451) for the design of the CO2−2-amino-2-methyl-propanol absorbers is adopted and improved for the design of the CO2−monoethanolamine absorber. The influence of the application of different mass transfer correlations on the model’s performance is investigated. Analytical expressions for the calculation of the enhancement factor for the second order as well as the pseudo-first-order reaction regime are integrated in the model, and their impact on the model’s prediction is compared. The model has been successfully applied to CO2 absorber packed columns and validated against pilot plant data with good agreement. ISSN : 0888-5885 En ligne : Absorber Model for CO2 Capture by Monoethanolamine Exemplaires
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Titre : Low-energy distillation-membrane separation process Type de document : texte imprimé Auteurs : Yu Huang, Auteur ; Richard W. Baker, Auteur ; Leland M. Vane, Auteur Année de publication : 2010 Article en page(s) : pp. 3760–3768 Langues : Anglais (eng) Mots-clés : Energy Distillation-membrane Separation process Résumé : A low-energy separation process combining distillation and membrane vapor permeation is introduced as an alternative to conventional distillation. The process can be applied to any liquid mixture for which appropriate selective membranes are available. However, in this paper, the discussion is limited to water/organic solvent mixtures using membranes that preferentially permeate water. Such membranes are available. The process is illustrated with two mixtures: ethanol (light component)/water (heavy component) and acetic acid (heavy component)/water (light component) mixtures. In both cases, the combination process reduces the energy consumption of the separation to half that of simple distillation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901545r
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3760–3768[article] Low-energy distillation-membrane separation process [texte imprimé] / Yu Huang, Auteur ; Richard W. Baker, Auteur ; Leland M. Vane, Auteur . - 2010 . - pp. 3760–3768.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3760–3768
Mots-clés : Energy Distillation-membrane Separation process Résumé : A low-energy separation process combining distillation and membrane vapor permeation is introduced as an alternative to conventional distillation. The process can be applied to any liquid mixture for which appropriate selective membranes are available. However, in this paper, the discussion is limited to water/organic solvent mixtures using membranes that preferentially permeate water. Such membranes are available. The process is illustrated with two mixtures: ethanol (light component)/water (heavy component) and acetic acid (heavy component)/water (light component) mixtures. In both cases, the combination process reduces the energy consumption of the separation to half that of simple distillation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901545r Exemplaires
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Titre : Effect of collector interfacial tension on coal flotation of different particle sizes Type de document : texte imprimé Auteurs : Li Ping Ding, Auteur Année de publication : 2010 Article en page(s) : pp. 3769–3775 Langues : Anglais (eng) Mots-clés : Interfacial Tension Coal Flotation Particle Résumé : Collectors are important for the effective operation of flotation process. In this work, a new collector was evaluated and compared with diesel oil to investigate its effect on coal flotation. The kinetics of collector spreading on hydrophobic and hydrophilic coal surfaces was studied by measuring the contact angle at coal−oil−water three-phase contact line versus time for the new collector and diesel oil, respectively. The interfacial tensions of each collector with water, as well as their binary mixtures at different compositions, were also studied to elucidate the difference between these two collectors. The performance of the new collector on bench-scale flotation of a hard-to-float coal was compared with that of diesel oil. Both flotation recovery and selectivity were improved with the adoption of the new collector. Comparing with diesel oil, the better flotation results obtained using the new collector can be attributed to the lower interfacial tension of the latter, resulting in faster collector spreading on coal particle surface and possible smaller collector droplet size formed by dispersion in a mechanical stirring cell. The size assay of the flotation concentrates indicated that the flotation recovery of medium-to-coarse coal particles (38−600 μm) increased as the collector interfacial tension decreased. However, there may be an optimal value of collector interfacial tension, corresponding to the maximum flotation recovery for ultrafine coals of −38 μm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901813j
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3769–3775[article] Effect of collector interfacial tension on coal flotation of different particle sizes [texte imprimé] / Li Ping Ding, Auteur . - 2010 . - pp. 3769–3775.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3769–3775
Mots-clés : Interfacial Tension Coal Flotation Particle Résumé : Collectors are important for the effective operation of flotation process. In this work, a new collector was evaluated and compared with diesel oil to investigate its effect on coal flotation. The kinetics of collector spreading on hydrophobic and hydrophilic coal surfaces was studied by measuring the contact angle at coal−oil−water three-phase contact line versus time for the new collector and diesel oil, respectively. The interfacial tensions of each collector with water, as well as their binary mixtures at different compositions, were also studied to elucidate the difference between these two collectors. The performance of the new collector on bench-scale flotation of a hard-to-float coal was compared with that of diesel oil. Both flotation recovery and selectivity were improved with the adoption of the new collector. Comparing with diesel oil, the better flotation results obtained using the new collector can be attributed to the lower interfacial tension of the latter, resulting in faster collector spreading on coal particle surface and possible smaller collector droplet size formed by dispersion in a mechanical stirring cell. The size assay of the flotation concentrates indicated that the flotation recovery of medium-to-coarse coal particles (38−600 μm) increased as the collector interfacial tension decreased. However, there may be an optimal value of collector interfacial tension, corresponding to the maximum flotation recovery for ultrafine coals of −38 μm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901813j Exemplaires
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Titre : Study of the heat of absorption of CO2 in aqueous ammonia : comparison between experimental data and model predictions Type de document : texte imprimé Auteurs : Feng Qin, Auteur ; Shujuan Wang, Auteur ; Inna Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 3776–3784 Langues : Anglais (eng) Mots-clés : Heat Absorption CO2 Aqueous Ammonia Experimental Data Model Résumé : Differential enthalpies of absorption of CO2 in aqueous ammonia were predicted based on reaction equilibrium constants using the Gibbs−Helmholtz equation. The reaction equilibrium constants were selected from the literature and integrated into an electrolyte-NRTL model and the model proposed by Edwards, in which the interaction parameters were previously and solely fitted from the NH3−CO2−H2O vapor−liquid equilibrium (VLE) data. The heat contributions of the individual reactions were taken into account in the total heat of absorption in both of the models. The heat of absorption was presented as a function of the CO2 loading and temperature. The predicted heats of absorption were compared with experimental data for temperatures ranging from 35 to 80 °C obtained in this work and also some other modeling results. The predicted results fit the experimental data well at lower temperatures, and also well at lower loadings when the temperature was higher, but the model was not good at high loadings and high temperature. The paper suggested that the heat of absorption data should also be included when parameters were fit together with VLE data in order to predict the heat of absorption well over a wide range of temperatures and loadings. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901869j
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3776–3784[article] Study of the heat of absorption of CO2 in aqueous ammonia : comparison between experimental data and model predictions [texte imprimé] / Feng Qin, Auteur ; Shujuan Wang, Auteur ; Inna Kim, Auteur . - 2010 . - pp. 3776–3784.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3776–3784
Mots-clés : Heat Absorption CO2 Aqueous Ammonia Experimental Data Model Résumé : Differential enthalpies of absorption of CO2 in aqueous ammonia were predicted based on reaction equilibrium constants using the Gibbs−Helmholtz equation. The reaction equilibrium constants were selected from the literature and integrated into an electrolyte-NRTL model and the model proposed by Edwards, in which the interaction parameters were previously and solely fitted from the NH3−CO2−H2O vapor−liquid equilibrium (VLE) data. The heat contributions of the individual reactions were taken into account in the total heat of absorption in both of the models. The heat of absorption was presented as a function of the CO2 loading and temperature. The predicted heats of absorption were compared with experimental data for temperatures ranging from 35 to 80 °C obtained in this work and also some other modeling results. The predicted results fit the experimental data well at lower temperatures, and also well at lower loadings when the temperature was higher, but the model was not good at high loadings and high temperature. The paper suggested that the heat of absorption data should also be included when parameters were fit together with VLE data in order to predict the heat of absorption well over a wide range of temperatures and loadings. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901869j Exemplaires
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Titre : Separation of an acetone−methanol mixture by pressure-swing batch distillation in a double-column system with and without thermal integration Type de document : texte imprimé Auteurs : Gabor Modla, Auteur ; Peter Lang, Auteur Année de publication : 2010 Article en page(s) : pp. 3785–3793 Langues : Anglais (eng) Mots-clés : Acetone− Methanol Mixture Batch Distillation Thermal Integration Résumé : Pressure-swing batch distillation in a double-column system is suggested for the separation of an acetone−methanol pressure-sensitive azeotropic mixture. The studied column configuration is the double-column batch stripper in open mode. We investigated this separation by rigorous simulation using a professional dynamic flow-sheet simulator. The influence of the most important operational parameters is studied. The energy demand of the separation is converted to carbon dioxide emission. The two columns can be thermally integrated to save energy. The effectiveness of thermal coupling is also investigated at different pressure gaps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019352
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3785–3793[article] Separation of an acetone−methanol mixture by pressure-swing batch distillation in a double-column system with and without thermal integration [texte imprimé] / Gabor Modla, Auteur ; Peter Lang, Auteur . - 2010 . - pp. 3785–3793.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3785–3793
Mots-clés : Acetone− Methanol Mixture Batch Distillation Thermal Integration Résumé : Pressure-swing batch distillation in a double-column system is suggested for the separation of an acetone−methanol pressure-sensitive azeotropic mixture. The studied column configuration is the double-column batch stripper in open mode. We investigated this separation by rigorous simulation using a professional dynamic flow-sheet simulator. The influence of the most important operational parameters is studied. The energy demand of the separation is converted to carbon dioxide emission. The two columns can be thermally integrated to save energy. The effectiveness of thermal coupling is also investigated at different pressure gaps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019352 Exemplaires
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Titre : Minimization of chemicals use during adsorptive recovery of succinic acid Type de document : texte imprimé Auteurs : Çağri Efe, Auteur ; Mervin Pieterse, Auteur ; Jorge Gascon, Auteur Année de publication : 2010 Article en page(s) : pp. 3794–3801 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Chemicals Adsorptive Succinic Acid Résumé : In adsorptive separation processes, regeneration of the adsorbent plays an important role. Depending on the type of product the regeneration strategy might differ from one process to another. In this study, the desorption of succinic acid from a high silica ZSM-5 adsorbent is studied, using displacement by an organic solvent or CO2, or temperature swing. According to a number of process criteria and solvent selection criteria, 2-butanone performed better than the other displacing agents studied. However, the subsequent regeneration step involved desorption of butanone, which proved to be difficult and required a temperature above the normal boiling point of water under elevated pressures. Such a temperature swing with hot water can also be applied for direct succinic acid desorption without intermediate displacement by butanone. A countercurrent continuous adsorption process was modeled to compare these options. Direct temperature swing using pressurized water at >100 °C proved to be more attractive to achieve a sustainable process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000168
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3794–3801[article] Minimization of chemicals use during adsorptive recovery of succinic acid [texte imprimé] / Çağri Efe, Auteur ; Mervin Pieterse, Auteur ; Jorge Gascon, Auteur . - 2010 . - pp. 3794–3801.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3794–3801
Mots-clés : Chemicals Adsorptive Succinic Acid Résumé : In adsorptive separation processes, regeneration of the adsorbent plays an important role. Depending on the type of product the regeneration strategy might differ from one process to another. In this study, the desorption of succinic acid from a high silica ZSM-5 adsorbent is studied, using displacement by an organic solvent or CO2, or temperature swing. According to a number of process criteria and solvent selection criteria, 2-butanone performed better than the other displacing agents studied. However, the subsequent regeneration step involved desorption of butanone, which proved to be difficult and required a temperature above the normal boiling point of water under elevated pressures. Such a temperature swing with hot water can also be applied for direct succinic acid desorption without intermediate displacement by butanone. A countercurrent continuous adsorption process was modeled to compare these options. Direct temperature swing using pressurized water at >100 °C proved to be more attractive to achieve a sustainable process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000168 Exemplaires
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Titre : Improved coating window for slot coating Type de document : texte imprimé Auteurs : Chih-Ping Chin, Auteur ; Ho-Shing Wu, Auteur ; Shaw S. Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 3802–3809 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Coating low viscosity with high Résumé : Slot die is a premetered coating operation in which the coating solution is extruded from a feed slot onto the surface of a substrate passing through. The defect-free region of operation is known as the “coating window”, and the wider it is, the more versatile the operation will be. The slot-coating experiments reported here were carried out with two types of coating solutions, a hard coating solution with low viscosity and a polysilica solution with high viscosity. The coating windows were measured as flow rates q versus minimum and maximum coating speeds, Vmin and Vmax, respectively. Therefore, at a given flow rate of the coating solution, there exists a minimum speed and a maximum speed that border the corresponding coating window, outside which coating defects occur. Also, in our experiments, the coating windows shifted to higher coating speed and obtained thinner coating film thicknesses through different settings of the die angle to the substrate and different geometries of die lips. The data showed that the coating windows shifted to higher speed and thinner film thicknesses when the die angle and the geometry of the die lips were varied appropriately. These results have important practical implications. The fundamental principles involved here are also applicable to other premetered coating processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801900t
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3802–3809[article] Improved coating window for slot coating [texte imprimé] / Chih-Ping Chin, Auteur ; Ho-Shing Wu, Auteur ; Shaw S. Wang, Auteur . - 2010 . - pp. 3802–3809.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3802–3809
Mots-clés : Coating low viscosity with high Résumé : Slot die is a premetered coating operation in which the coating solution is extruded from a feed slot onto the surface of a substrate passing through. The defect-free region of operation is known as the “coating window”, and the wider it is, the more versatile the operation will be. The slot-coating experiments reported here were carried out with two types of coating solutions, a hard coating solution with low viscosity and a polysilica solution with high viscosity. The coating windows were measured as flow rates q versus minimum and maximum coating speeds, Vmin and Vmax, respectively. Therefore, at a given flow rate of the coating solution, there exists a minimum speed and a maximum speed that border the corresponding coating window, outside which coating defects occur. Also, in our experiments, the coating windows shifted to higher coating speed and obtained thinner coating film thicknesses through different settings of the die angle to the substrate and different geometries of die lips. The data showed that the coating windows shifted to higher speed and thinner film thicknesses when the die angle and the geometry of the die lips were varied appropriately. These results have important practical implications. The fundamental principles involved here are also applicable to other premetered coating processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801900t Exemplaires
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Titre : Membrane emulsification with oscillating and stationary membranes Type de document : texte imprimé Auteurs : Richard G. Holdich, Auteur ; Marijana M. Dragosavac, Auteur ; Goran T. Vladisavljević, Auteur Année de publication : 2010 Article en page(s) : pp. 3810–3817 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Membrane Emulsification Stationary Membranes Résumé : Membrane emulsification of sunflower oil in aqueous solutions of 2% (v/v) Tween 20 was performed using a stationary disk membrane with a rotating paddle stirrer and, for comparison, a tubular membrane oscillating normal to the direction of oil flow in an otherwise stationary continuous phase. The oscillation frequency ranged from 10 to 90 Hz. The oil was injected through a sieve-type membrane with a 10 μm pore size and 180 μm between pore spacing at low flux rates to minimize any droplet interference. Using the same membrane material under identical peak shear conditions in both systems, smaller and more uniform drops (30−50 μm median sizes) were produced in the oscillating system. In oscillation, the drop size was modeled by a force balance, including a correction for neck formation at the pore surface, but in the rotating paddle system, neck formation did not appear to be relevant. Drop size was not found to be frequency of oscillation dependent, apart from its influence on the shear stress at the membrane surface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900531n
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3810–3817[article] Membrane emulsification with oscillating and stationary membranes [texte imprimé] / Richard G. Holdich, Auteur ; Marijana M. Dragosavac, Auteur ; Goran T. Vladisavljević, Auteur . - 2010 . - pp. 3810–3817.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3810–3817
Mots-clés : Membrane Emulsification Stationary Membranes Résumé : Membrane emulsification of sunflower oil in aqueous solutions of 2% (v/v) Tween 20 was performed using a stationary disk membrane with a rotating paddle stirrer and, for comparison, a tubular membrane oscillating normal to the direction of oil flow in an otherwise stationary continuous phase. The oscillation frequency ranged from 10 to 90 Hz. The oil was injected through a sieve-type membrane with a 10 μm pore size and 180 μm between pore spacing at low flux rates to minimize any droplet interference. Using the same membrane material under identical peak shear conditions in both systems, smaller and more uniform drops (30−50 μm median sizes) were produced in the oscillating system. In oscillation, the drop size was modeled by a force balance, including a correction for neck formation at the pore surface, but in the rotating paddle system, neck formation did not appear to be relevant. Drop size was not found to be frequency of oscillation dependent, apart from its influence on the shear stress at the membrane surface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900531n Exemplaires
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Titre : Ferrous Ion effects on the stability and properties of oil-in-water emulsions formulated by membrane emulsification Type de document : texte imprimé Auteurs : Xavier Bernat, Auteur ; Emma Piacentini, Auteur ; Fabio Bazzarelli, Auteur Année de publication : 2010 Article en page(s) : pp. 3818–3829 Langues : Anglais (eng) Mots-clés : Ferrous Ion Oil Water Emulsions Membrane Emulsification Résumé : This study aimed at investigating the effect of the presence of Fe(II) cations on the stability of oil-in-water (O/W) emulsions produced by membrane emulsification. Both stirred and cross-flow emulsification methods have been used. The influence of fluid dynamics parameters and phases composition has been investigated. Results have shown that Fe(II) negatively affects the stability of O/W emulsions and that the destabilization effect increases with Fe(II) concentration. However, emulsion stability also depended on emulsification variables, such as percentage of emulsifier, emulsified oil percentage, and membrane pore size. In particular, the main destabilization phenomenon is the decrease on the net charge of the emulsion droplets, which causes agglomeration of the droplets resulting in coalescence and, in some cases, breakage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901491k
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3818–3829[article] Ferrous Ion effects on the stability and properties of oil-in-water emulsions formulated by membrane emulsification [texte imprimé] / Xavier Bernat, Auteur ; Emma Piacentini, Auteur ; Fabio Bazzarelli, Auteur . - 2010 . - pp. 3818–3829.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3818–3829
Mots-clés : Ferrous Ion Oil Water Emulsions Membrane Emulsification Résumé : This study aimed at investigating the effect of the presence of Fe(II) cations on the stability of oil-in-water (O/W) emulsions produced by membrane emulsification. Both stirred and cross-flow emulsification methods have been used. The influence of fluid dynamics parameters and phases composition has been investigated. Results have shown that Fe(II) negatively affects the stability of O/W emulsions and that the destabilization effect increases with Fe(II) concentration. However, emulsion stability also depended on emulsification variables, such as percentage of emulsifier, emulsified oil percentage, and membrane pore size. In particular, the main destabilization phenomenon is the decrease on the net charge of the emulsion droplets, which causes agglomeration of the droplets resulting in coalescence and, in some cases, breakage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901491k Exemplaires
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Titre : The Characteristics of Pressure Drop in Microchannels Type de document : texte imprimé Auteurs : Hongjiu Su, Auteur ; Haining Niu, Auteur ; Liwei Pan, Auteur Année de publication : 2010 Article en page(s) : pp. 3830–3839 Langues : Anglais (eng) Mots-clés : Microchannels Résumé : The characteristics of the pressure drop of fluid were investigated in three different kinds of stainless steel microchannels with diameter of 0.56, 1.00, and 1.80 mm based on the absorption in the microchannels. For the single-phase flow pressure drop, nitrogen being used as the test fluid, it was found that the transition between the laminar and turbulent flow occurred at the Reynolds number of about 2000, which was different from some previous reports in which the early flow transition was observed in microchannels. For the two-phase flow pressure drop, an industrial chemical absorbent (40 wt % MDEA solution) and nitrogen being taken as the working fluid, it was found that the existing correlations including the homogeneous flow model and separated flow model failed to predict the experimental results because of the special operating condition in which the ratio of volumetric flow rate of gas to liquid phase ranged from 100 to 3400. A new correlation to predict the two-phase flow pressure drop was developed in the form of the Lockhart−Martinelli type which considered the effect of surface tension, gas phase inertial force, Reynolds number of liquid phase, and the Martinelli parameter. The predicted data with new correlation showed good agreement with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015045
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3830–3839[article] The Characteristics of Pressure Drop in Microchannels [texte imprimé] / Hongjiu Su, Auteur ; Haining Niu, Auteur ; Liwei Pan, Auteur . - 2010 . - pp. 3830–3839.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3830–3839
Mots-clés : Microchannels Résumé : The characteristics of the pressure drop of fluid were investigated in three different kinds of stainless steel microchannels with diameter of 0.56, 1.00, and 1.80 mm based on the absorption in the microchannels. For the single-phase flow pressure drop, nitrogen being used as the test fluid, it was found that the transition between the laminar and turbulent flow occurred at the Reynolds number of about 2000, which was different from some previous reports in which the early flow transition was observed in microchannels. For the two-phase flow pressure drop, an industrial chemical absorbent (40 wt % MDEA solution) and nitrogen being taken as the working fluid, it was found that the existing correlations including the homogeneous flow model and separated flow model failed to predict the experimental results because of the special operating condition in which the ratio of volumetric flow rate of gas to liquid phase ranged from 100 to 3400. A new correlation to predict the two-phase flow pressure drop was developed in the form of the Lockhart−Martinelli type which considered the effect of surface tension, gas phase inertial force, Reynolds number of liquid phase, and the Martinelli parameter. The predicted data with new correlation showed good agreement with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015045 Exemplaires
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Titre : Study of liquid weeping at a tapered orifice in a bubble column reactor by a computer-aided image analysis algorithm Type de document : texte imprimé Auteurs : Md. Iqbal Hossain, Auteur ; Si Qi Pang, Auteur ; Qing Xi Pang, Auteur Année de publication : 2010 Article en page(s) : pp. 3840–3848 Langues : Anglais (eng) Mots-clés : Liquid Weeping Algorithm Résumé : Understanding the phenomenon of liquid weeping requires knowledge of the bubbling and weeping cycle. Hence, an image analysis algorithm is developed and subsequently coupled with high-speed imaging techniques to examine the different stages in the bubbling and weeping cycle automatically. The bubbling and weeping cycle is studied under various operating conditions, using the developed algorithm, coupled with high-speed imaging techniques and the pressure fluctuation measurement. The effect of orifice angle (where the orifice angle is a measure of the orifice taperness) on the liquid weeping rate is evaluated over a range of superficial orifice gas velocities and justified with the aid of the developed algorithm, coupled with high-speed imaging techniques. A gas distributor plate with negative angle orifices is recommended for improved operation of industrial bubble column reactors over the range of superficial orifice gas velocities considered in this study, because it substantially decreases the liquid weeping rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901516f
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3840–3848[article] Study of liquid weeping at a tapered orifice in a bubble column reactor by a computer-aided image analysis algorithm [texte imprimé] / Md. Iqbal Hossain, Auteur ; Si Qi Pang, Auteur ; Qing Xi Pang, Auteur . - 2010 . - pp. 3840–3848.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3840–3848
Mots-clés : Liquid Weeping Algorithm Résumé : Understanding the phenomenon of liquid weeping requires knowledge of the bubbling and weeping cycle. Hence, an image analysis algorithm is developed and subsequently coupled with high-speed imaging techniques to examine the different stages in the bubbling and weeping cycle automatically. The bubbling and weeping cycle is studied under various operating conditions, using the developed algorithm, coupled with high-speed imaging techniques and the pressure fluctuation measurement. The effect of orifice angle (where the orifice angle is a measure of the orifice taperness) on the liquid weeping rate is evaluated over a range of superficial orifice gas velocities and justified with the aid of the developed algorithm, coupled with high-speed imaging techniques. A gas distributor plate with negative angle orifices is recommended for improved operation of industrial bubble column reactors over the range of superficial orifice gas velocities considered in this study, because it substantially decreases the liquid weeping rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901516f Exemplaires
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Titre : Effect of blockage on heat transfer from a sphere in power-law fluids Type de document : texte imprimé Auteurs : Daoyun Song, Auteur ; Rakesh K. Gupta, Auteur Année de publication : 2010 Article en page(s) : pp. 3849–3861 Langues : Anglais (eng) Mots-clés : BlockageHeat Transfer Heat Tranphere Power-Law Fluids Résumé : This work endeavors to elucidate the influence of confining walls on the convective heat transfer from a sphere to power-law fluids. The governing equations (mass, momentum, and thermal energy) have been solved numerically over the following ranges of conditions: power-law index, 0.2−1, i.e., only for shear-thinning fluid behavior; sphere Reynolds number, 5−100; sphere-to-tube-diameter ratio, 0−0.5; and Prandtl number, 1−100. Extensive results of the local and surface averaged values of the Nusselt number are presented herein to delineate the influence of each of the aforementioned parameters on the rate of heat transfer from a sphere. Broadly speaking, the Nusselt number shows positive dependence on both the Reynolds and Prandtl numbers. All else being equal, shear-thinning fluid behavior is seen to facilitate heat transfer with reference to that in Newtonian fluids. Indeed, it is possible to augment the rate of heat transfer by up to 60−70% under appropriate conditions. However, the imposition of confining walls is seen to limit the enhancement in heat transfer, especially at low Reynolds and/or Prandtl numbers. Therefore, the severity of confinement together with the values of the Reynolds and Prandtl numbers influences the value of the Nusselt number in an intricate manner. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901524h
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3849–3861[article] Effect of blockage on heat transfer from a sphere in power-law fluids [texte imprimé] / Daoyun Song, Auteur ; Rakesh K. Gupta, Auteur . - 2010 . - pp. 3849–3861.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3849–3861
Mots-clés : BlockageHeat Transfer Heat Tranphere Power-Law Fluids Résumé : This work endeavors to elucidate the influence of confining walls on the convective heat transfer from a sphere to power-law fluids. The governing equations (mass, momentum, and thermal energy) have been solved numerically over the following ranges of conditions: power-law index, 0.2−1, i.e., only for shear-thinning fluid behavior; sphere Reynolds number, 5−100; sphere-to-tube-diameter ratio, 0−0.5; and Prandtl number, 1−100. Extensive results of the local and surface averaged values of the Nusselt number are presented herein to delineate the influence of each of the aforementioned parameters on the rate of heat transfer from a sphere. Broadly speaking, the Nusselt number shows positive dependence on both the Reynolds and Prandtl numbers. All else being equal, shear-thinning fluid behavior is seen to facilitate heat transfer with reference to that in Newtonian fluids. Indeed, it is possible to augment the rate of heat transfer by up to 60−70% under appropriate conditions. However, the imposition of confining walls is seen to limit the enhancement in heat transfer, especially at low Reynolds and/or Prandtl numbers. Therefore, the severity of confinement together with the values of the Reynolds and Prandtl numbers influences the value of the Nusselt number in an intricate manner. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901524h Exemplaires
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Titre : Fast high-resolution method for solving multidimensional population balances in crystallization Type de document : texte imprimé Auteurs : Aniruddha Majumder, Auteur ; Vinay Kariwala, Auteur ; Santosh Ansumali, Auteur Année de publication : 2010 Article en page(s) : pp. 3862–3872 Note générale : Industriay Chemistry Langues : Anglais (eng) Mots-clés : Multidimensional Population Balances Crystallization Résumé : High-resolution (HR) finite-volume methods can provide an accurate numerical solution of population balance equations describing crystallization processes. To satisfy the stability requirements, the time step (Δt) for the available HR methods needs to be selected conservatively, rendering them computationally expensive for processes with size-dependent growth rates. In this paper, we propose a coordinate transformation scheme to improve the solution time of HR methods applied to batch crystallization processes with nucleation and size-dependent growth. The coordinate transform takes advantage of the functional form that is used to describe the size dependency of the growth rate. Using benchmark examples, we demonstrate that the proposed method provides a more significant reduction in the solution time than existing HR methods, while retaining the same level of accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016946
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3862–3872[article] Fast high-resolution method for solving multidimensional population balances in crystallization [texte imprimé] / Aniruddha Majumder, Auteur ; Vinay Kariwala, Auteur ; Santosh Ansumali, Auteur . - 2010 . - pp. 3862–3872.
Industriay Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3862–3872
Mots-clés : Multidimensional Population Balances Crystallization Résumé : High-resolution (HR) finite-volume methods can provide an accurate numerical solution of population balance equations describing crystallization processes. To satisfy the stability requirements, the time step (Δt) for the available HR methods needs to be selected conservatively, rendering them computationally expensive for processes with size-dependent growth rates. In this paper, we propose a coordinate transformation scheme to improve the solution time of HR methods applied to batch crystallization processes with nucleation and size-dependent growth. The coordinate transform takes advantage of the functional form that is used to describe the size dependency of the growth rate. Using benchmark examples, we demonstrate that the proposed method provides a more significant reduction in the solution time than existing HR methods, while retaining the same level of accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016946 Exemplaires
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Titre : Morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate)/polycarbonate blends Type de document : texte imprimé Auteurs : Indose Aravind, Auteur ; Alain Boumod, Auteur ; Yves Grohens, Auteur Année de publication : 2010 Article en page(s) : pp. 3873–3882 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Morphology Dynamic Mechanical Thermal Crystallization Behaviors Poly Trimethylene terephthalate Polycarbonate Résumé : The phase morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/polycarbonate (PC) blends were studied. The phase morphology of the blends, investigated as a function of the composition, indicated a two-phase structure. Dynamic mechanical thermal analysis (DMTA) studies revealed that there is a shift in tan δmax toward each other especially in higher PTT contents. This is attributed to the small number of transesterification reactions most likely to occur under the reaction conditions that are more pronounced at higher PTT content. Thermogravimetric analysis revealed that PTT is more susceptible to thermal degradation than PC. The blends with a higher PC content showed a higher degradation temperature. However, the blends with a higher PTT content exhibited the lowest initial degradation temperature, which might be ascribed to its higher extent of transesterification reaction. The addition of PC to PTT increases the activation energy of the blends, which indicates an improvement in the thermal stability. The crystallization behavior of the blends was analyzed by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The DSC results showed that the crystallization behavior of PTT/PC blends was very much affected by the PC content. The onset and peak crystallization temperatures shifted to lower temperatures and the area of the crystallization exotherm decreased with an increase in the PC content. This suggests that the crystallization process of PTT was suppressed by the presence of PC. WAXD analysis revealed that that the intensity of the crystalline diffraction peaks of PTT decreased with an increase in the PC content in the blends. The amount of transesterification reactions occurring between PTT and PC is quantified by Fourier transform IR techniques; it is found that the amount of copolymer formed as a result of transesterification reactions is small, and hence this merely enhances the compatibility between the components. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901767y
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3873–3882[article] Morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate)/polycarbonate blends [texte imprimé] / Indose Aravind, Auteur ; Alain Boumod, Auteur ; Yves Grohens, Auteur . - 2010 . - pp. 3873–3882.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3873–3882
Mots-clés : Morphology Dynamic Mechanical Thermal Crystallization Behaviors Poly Trimethylene terephthalate Polycarbonate Résumé : The phase morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/polycarbonate (PC) blends were studied. The phase morphology of the blends, investigated as a function of the composition, indicated a two-phase structure. Dynamic mechanical thermal analysis (DMTA) studies revealed that there is a shift in tan δmax toward each other especially in higher PTT contents. This is attributed to the small number of transesterification reactions most likely to occur under the reaction conditions that are more pronounced at higher PTT content. Thermogravimetric analysis revealed that PTT is more susceptible to thermal degradation than PC. The blends with a higher PC content showed a higher degradation temperature. However, the blends with a higher PTT content exhibited the lowest initial degradation temperature, which might be ascribed to its higher extent of transesterification reaction. The addition of PC to PTT increases the activation energy of the blends, which indicates an improvement in the thermal stability. The crystallization behavior of the blends was analyzed by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The DSC results showed that the crystallization behavior of PTT/PC blends was very much affected by the PC content. The onset and peak crystallization temperatures shifted to lower temperatures and the area of the crystallization exotherm decreased with an increase in the PC content. This suggests that the crystallization process of PTT was suppressed by the presence of PC. WAXD analysis revealed that that the intensity of the crystalline diffraction peaks of PTT decreased with an increase in the PC content in the blends. The amount of transesterification reactions occurring between PTT and PC is quantified by Fourier transform IR techniques; it is found that the amount of copolymer formed as a result of transesterification reactions is small, and hence this merely enhances the compatibility between the components. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901767y Exemplaires
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Titre : Prediction of partition coefficients of organic compounds in Ionic liquids : use of a linear solvation energy relationship with parameters calculated through a group contribution method Type de document : texte imprimé Auteurs : Anne-Laure Revelli, Auteur ; Fabrice Mutelet, Auteur ; Jaubert, Jean-Noël, Auteur Année de publication : 2010 Article en page(s) : pp. 3883–3892 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : PredictionOrganic Compounds CoLiquids Energy Relationship Résumé : A group contribution method is proposed to determine linear solvation energy relationship parameters (GC-LSER) in view of estimating the gas-to-ionic liquid partition coefficients and water-to-ionic liquid partition coefficients. Large sets of partition coefficients were analyzed using the Abraham solvation model to determine the contributions of 21 groups: 12 groups characterizing the cations and 9 groups for the anions. The derived equations correlate the experimental gas-to-ionic liquid and water-to-ionic liquid partition coefficient data to within 0.15 and 0.17 log units, respectively. The 21 group-parameters can be used to predict the partition coefficients of solutes in alkyl or functionalized ionic liquids with a good accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901776z
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3883–3892[article] Prediction of partition coefficients of organic compounds in Ionic liquids : use of a linear solvation energy relationship with parameters calculated through a group contribution method [texte imprimé] / Anne-Laure Revelli, Auteur ; Fabrice Mutelet, Auteur ; Jaubert, Jean-Noël, Auteur . - 2010 . - pp. 3883–3892.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3883–3892
Mots-clés : PredictionOrganic Compounds CoLiquids Energy Relationship Résumé : A group contribution method is proposed to determine linear solvation energy relationship parameters (GC-LSER) in view of estimating the gas-to-ionic liquid partition coefficients and water-to-ionic liquid partition coefficients. Large sets of partition coefficients were analyzed using the Abraham solvation model to determine the contributions of 21 groups: 12 groups characterizing the cations and 9 groups for the anions. The derived equations correlate the experimental gas-to-ionic liquid and water-to-ionic liquid partition coefficient data to within 0.15 and 0.17 log units, respectively. The 21 group-parameters can be used to predict the partition coefficients of solutes in alkyl or functionalized ionic liquids with a good accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901776z Exemplaires
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Titre : Measurement and prediction of vapor−liquid equilibrium of aqueous 1-ethyl-3-methylimidazolium-based Ionic liquid systems Type de document : texte imprimé Auteurs : Luke D. Simoni, Auteur ; Lindsay E. Ficke, Auteur ; Caitlin A. Lambert ,, Auteur Année de publication : 2010 Article en page(s) : pp. 3893–3901 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Measurement Prediction Vapor− Liquid Equilibrium Aqueous Ethy methylimidazolium Ionic Liquid Résumé : Isothermal vapor−liquid equilibria were determined for two binary ionic liquid + water systems, from 323.3 to 368.2 K, and water mole fractions greater than 0.5. The ionic liquids used were 1-ethyl-3-methylimidazolium trifluoromethanesulfonate and 1-ethyl-3-methylimidazolium trifluoroacetate. In addition, predictive thermodynamic modeling of the vapor−liquid equilibrium was performed by correlating the nonrandom two-liquid,(39) universal quasi-chemical,(40) and electrolyte-NRTL(41) models to previously measured excess enthalpy and infinite dilution activity coefficient data from the literature. For each of the systems studied at least two of the models provided adequate predictions of vapor pressure and water activity coefficients. The good predictions of vapor−liquid equilibria by these common activity coefficient models lead us to favor excess enthalpy and infinite dilution activity coefficient data over vapor−liquid equilibria data, since predictions of excess enthalpies from vapor−liquid equilibria are not satisfactory. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017868
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3893–3901[article] Measurement and prediction of vapor−liquid equilibrium of aqueous 1-ethyl-3-methylimidazolium-based Ionic liquid systems [texte imprimé] / Luke D. Simoni, Auteur ; Lindsay E. Ficke, Auteur ; Caitlin A. Lambert ,, Auteur . - 2010 . - pp. 3893–3901.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3893–3901
Mots-clés : Measurement Prediction Vapor− Liquid Equilibrium Aqueous Ethy methylimidazolium Ionic Liquid Résumé : Isothermal vapor−liquid equilibria were determined for two binary ionic liquid + water systems, from 323.3 to 368.2 K, and water mole fractions greater than 0.5. The ionic liquids used were 1-ethyl-3-methylimidazolium trifluoromethanesulfonate and 1-ethyl-3-methylimidazolium trifluoroacetate. In addition, predictive thermodynamic modeling of the vapor−liquid equilibrium was performed by correlating the nonrandom two-liquid,(39) universal quasi-chemical,(40) and electrolyte-NRTL(41) models to previously measured excess enthalpy and infinite dilution activity coefficient data from the literature. For each of the systems studied at least two of the models provided adequate predictions of vapor pressure and water activity coefficients. The good predictions of vapor−liquid equilibria by these common activity coefficient models lead us to favor excess enthalpy and infinite dilution activity coefficient data over vapor−liquid equilibria data, since predictions of excess enthalpies from vapor−liquid equilibria are not satisfactory. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017868 Exemplaires
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Titre : Significant differences in the hydrolysis behavior of amorphous and crystalline portions within microcrystalline cellulose in hot-compressed water Type de document : texte imprimé Auteurs : Yun Yu, Auteur ; Hongwei Wu, Auteur Année de publication : 2010 Article en page(s) : pp. 3902–3909 Note générale : Idustrial Chemistry Langues : Anglais (eng) Mots-clés : Microcrystalline Cellulose Hot-Compressed Water Hydrolysis Résumé : Due to the presence of amorphous structure in microcrystalline cellulose, the reactivity of microcrystalline cellulose exhibits a considerable reduction in the initial stage during hydrolysis in hot-compressed water (HCW). Further analysis of the liquid products obtained at various temperatures suggests that the amorphous portion within microcrystalline cellulose contains some short glucose chain segments hinged with crystalline cellulose via weak bonds (e.g., hydrogen bonds). These short chain segments are reactive components responsible for the formation of C4−C13 oligomers in the primary liquid products during hydrolysis in HCW at temperatures as low as 100 °C. The minimal temperature for breaking the glycosidic bonds in those short chain segments to form glucose monomer from amorphous portion within microcrystalline cellulose is 150 °C. However, the minimal temperature at which glucose monomer starts to be produced from the crystalline portion within microcrystalline cellulose is around 180 °C, apparently due to the limited accessibility of the glycosidic bonds in the crystalline portion to HCW as a result of the strong intra- and intermolecular hydrogen bonding networks. The differences of chain length and hydrogen bonding pattern between amorphous and crystalline cellulose also greatly affect the distribution of glucose oligomers in their liquid products during hydrolysis in HCW. Generally, amorphous cellulose produces more glucose monomers and oligomers at the same hydrolysis temperature, but the selectivity ratios of glucose oligomers in the primary liquid products from amorphous and crystalline portions do not show a monotonic trend with the degree of polymerization, at least partly resulting from the presence of shorter glucose chain segments in the amorphous portion within the microcrystalline cellulose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901925g
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3902–3909[article] Significant differences in the hydrolysis behavior of amorphous and crystalline portions within microcrystalline cellulose in hot-compressed water [texte imprimé] / Yun Yu, Auteur ; Hongwei Wu, Auteur . - 2010 . - pp. 3902–3909.
Idustrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3902–3909
Mots-clés : Microcrystalline Cellulose Hot-Compressed Water Hydrolysis Résumé : Due to the presence of amorphous structure in microcrystalline cellulose, the reactivity of microcrystalline cellulose exhibits a considerable reduction in the initial stage during hydrolysis in hot-compressed water (HCW). Further analysis of the liquid products obtained at various temperatures suggests that the amorphous portion within microcrystalline cellulose contains some short glucose chain segments hinged with crystalline cellulose via weak bonds (e.g., hydrogen bonds). These short chain segments are reactive components responsible for the formation of C4−C13 oligomers in the primary liquid products during hydrolysis in HCW at temperatures as low as 100 °C. The minimal temperature for breaking the glycosidic bonds in those short chain segments to form glucose monomer from amorphous portion within microcrystalline cellulose is 150 °C. However, the minimal temperature at which glucose monomer starts to be produced from the crystalline portion within microcrystalline cellulose is around 180 °C, apparently due to the limited accessibility of the glycosidic bonds in the crystalline portion to HCW as a result of the strong intra- and intermolecular hydrogen bonding networks. The differences of chain length and hydrogen bonding pattern between amorphous and crystalline cellulose also greatly affect the distribution of glucose oligomers in their liquid products during hydrolysis in HCW. Generally, amorphous cellulose produces more glucose monomers and oligomers at the same hydrolysis temperature, but the selectivity ratios of glucose oligomers in the primary liquid products from amorphous and crystalline portions do not show a monotonic trend with the degree of polymerization, at least partly resulting from the presence of shorter glucose chain segments in the amorphous portion within the microcrystalline cellulose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901925g Exemplaires
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Titre : Solubility of CO2 in aqueous solutions of methionine and in aqueous solutions of (K2CO3 and methionine) Type de document : texte imprimé Auteurs : Jacek Kumełan, Auteur ; Álvaro Pérez-Salado Kamps, Auteur ; Maurer, Gerd, Auteur Année de publication : 2010 Article en page(s) : pp. 3910–3918 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Aqueous Solutions Methionine Résumé : The influence of the amino acid d,l-methionine on the solubility of carbon dioxide in pure water and in aqueous solutions of potassium carbonate was investigated. The solubility was measured with a high-pressure view-cell technique operating on the synthetic method. Temperature and total pressure ranged from about 353 to 393 K and 1 to 10 MPa, respectively. The molality of methionine was between about 0.42 mol·(kg H2O)−1 and 0.83 mol·(kg H2O)−1. The molality of potassium carbonate was about 1.25 and 2.5 mol·(kg H2O)−1. The solubility of carbon dioxide in aqueous solutions of potassium carbonate and methionine is influenced by chemical reactions: On one side, dissolving carbon dioxide in an aqueous solution of potassium carbonate shifts the chemical reaction equilibrium from carbonate to bicarbonate and, on the other side, methionine is a zwitterionic substance. The new experimental results are correlated using an extension of a previously published thermodynamic model for the solubility of carbon dioxide in aqueous solutions of potassium carbonate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902032n
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3910–3918[article] Solubility of CO2 in aqueous solutions of methionine and in aqueous solutions of (K2CO3 and methionine) [texte imprimé] / Jacek Kumełan, Auteur ; Álvaro Pérez-Salado Kamps, Auteur ; Maurer, Gerd, Auteur . - 2010 . - pp. 3910–3918.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3910–3918
Mots-clés : Aqueous Solutions Methionine Résumé : The influence of the amino acid d,l-methionine on the solubility of carbon dioxide in pure water and in aqueous solutions of potassium carbonate was investigated. The solubility was measured with a high-pressure view-cell technique operating on the synthetic method. Temperature and total pressure ranged from about 353 to 393 K and 1 to 10 MPa, respectively. The molality of methionine was between about 0.42 mol·(kg H2O)−1 and 0.83 mol·(kg H2O)−1. The molality of potassium carbonate was about 1.25 and 2.5 mol·(kg H2O)−1. The solubility of carbon dioxide in aqueous solutions of potassium carbonate and methionine is influenced by chemical reactions: On one side, dissolving carbon dioxide in an aqueous solution of potassium carbonate shifts the chemical reaction equilibrium from carbonate to bicarbonate and, on the other side, methionine is a zwitterionic substance. The new experimental results are correlated using an extension of a previously published thermodynamic model for the solubility of carbon dioxide in aqueous solutions of potassium carbonate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902032n Exemplaires
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Titre : Evolution of primary liquid products and evidence of in situ structural changes in cellulose with conversion during hydrolysis in hot-compressed water Type de document : texte imprimé Auteurs : Yun Yu, Auteur ; Hongwei Wu, Auteur Année de publication : 2010 Article en page(s) : pp. 3919–3925 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Liquid Evidence Cellulose Hydrolysis Hot-Compressed Water Résumé : This study shows the dynamic evolution of the primary liquid products with conversion during the hydrolysis of both amorphous and crystalline cellulose in hot-compressed water (HCW). The results suggest that the dynamic changes in cellulose structure occur during conversion and strongly depend on reaction temperature. Results from a set of purposely designed two-step experiments further confirm at least two mechanisms which may be responsible for such structural changes. One is the selective consumption of the reactive components within the intrinsically heterogeneous cellulose at early conversions. This mechanism dominates during the hydrolysis of at low temperatures, e.g., 180−200 °C for amorphous cellulose and 230 °C for microcrystalline cellulose. The other is the combined effects of various parallel reactions during hydrolysis in HCW, including cleavage of hydrogen bonds, degradation reactions, and cross-linking reactions. Enhanced hydrogen bond cleavage increases the production of glucose oligomers. However, parallel degradation reactions and cross-linking reactions decrease the selectivity of glucose oligomers. The effect of cross-linking of cellulose in HCW appears to increase with temperature and becomes significant at 270 °C, leading to a structural condensation and hence a reduction in the specific reactivity of cellulose and the selectivity of glucose oligomers in the primary liquid products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902020t
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3919–3925[article] Evolution of primary liquid products and evidence of in situ structural changes in cellulose with conversion during hydrolysis in hot-compressed water [texte imprimé] / Yun Yu, Auteur ; Hongwei Wu, Auteur . - 2010 . - pp. 3919–3925.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3919–3925
Mots-clés : Liquid Evidence Cellulose Hydrolysis Hot-Compressed Water Résumé : This study shows the dynamic evolution of the primary liquid products with conversion during the hydrolysis of both amorphous and crystalline cellulose in hot-compressed water (HCW). The results suggest that the dynamic changes in cellulose structure occur during conversion and strongly depend on reaction temperature. Results from a set of purposely designed two-step experiments further confirm at least two mechanisms which may be responsible for such structural changes. One is the selective consumption of the reactive components within the intrinsically heterogeneous cellulose at early conversions. This mechanism dominates during the hydrolysis of at low temperatures, e.g., 180−200 °C for amorphous cellulose and 230 °C for microcrystalline cellulose. The other is the combined effects of various parallel reactions during hydrolysis in HCW, including cleavage of hydrogen bonds, degradation reactions, and cross-linking reactions. Enhanced hydrogen bond cleavage increases the production of glucose oligomers. However, parallel degradation reactions and cross-linking reactions decrease the selectivity of glucose oligomers. The effect of cross-linking of cellulose in HCW appears to increase with temperature and becomes significant at 270 °C, leading to a structural condensation and hence a reduction in the specific reactivity of cellulose and the selectivity of glucose oligomers in the primary liquid products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902020t Exemplaires
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Titre : Methane gas visualization using infrared imaging system and evaluation of temperature dependence of methane gas emissivity Type de document : texte imprimé Auteurs : Anisa Safitri, Auteur ; M. Sam Mannan, Auteur Année de publication : 2010 Article en page(s) : pp. 3926–3935 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Methane Gas Visualization Infrared Imaging System Temperature Emissivity Résumé : Infrared (IR) camera has been used widely in the industry to visualize gases that cannot be seen by the naked eye or a visual camera. The use of an infrared camera for gas imaging offers several advantages such as faster locating of gas leaks and easier understanding on how the gas travels and disperses. In addition, several types of infrared cameras have the capability to measure the temperature of target objects especially solid body objects. However, this facility has not been applied for measurement of gas temperature due to complex analysis on the physics of infrared imaging and some uncertainties related to the radiation heat transfer processes during temperature measurement that have not been well understood. The objective of this research is to make use of the infrared or thermal imaging system to provide a concise temperature distribution of a methane gas plume presented in the infrared image. However, the current technology in infrared imaging cannot provide the true temperature of a gas plume because the emissivity value is always assumed as unity, and the actual emissivity value of the gas is not integrated in the camera’s algorithm. The visualization of dispersed liquefied natural gas (LNG) vapor from LNG spills on the ground using a midwave thermal camera is presented in this work. Two types of infrared cameras were used: Amber Radiance 1 and GasFindIR, also known in industry as hydrocarbon camera. The infrared images or thermograms show that several factors affecting the temperature measurement are weather conditions, wind rose, atmospheric attenuation due to the presence of other radiation absorbing gases along the optic path, and gas emissivity. Gas emissivity is the main uncertainty in gas temperature measurement using thermal cameras. This research proposed a method to correct the gas temperature measured by a thermal camera by applying the emissivity factor calculated from a theoretical analysis on methane gas emissivity using the band absorption method. The study demonstrates that methane gas emissivity is a strong function of gas temperature; however, the effect of optical depth is insignificant. Because in this work, the infrared camera is used to visualize the LNG vapor, temperature dependence of methane emissivity at temperatures 110−300 K is evaluated and presented in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901340g
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3926–3935[article] Methane gas visualization using infrared imaging system and evaluation of temperature dependence of methane gas emissivity [texte imprimé] / Anisa Safitri, Auteur ; M. Sam Mannan, Auteur . - 2010 . - pp. 3926–3935.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3926–3935
Mots-clés : Methane Gas Visualization Infrared Imaging System Temperature Emissivity Résumé : Infrared (IR) camera has been used widely in the industry to visualize gases that cannot be seen by the naked eye or a visual camera. The use of an infrared camera for gas imaging offers several advantages such as faster locating of gas leaks and easier understanding on how the gas travels and disperses. In addition, several types of infrared cameras have the capability to measure the temperature of target objects especially solid body objects. However, this facility has not been applied for measurement of gas temperature due to complex analysis on the physics of infrared imaging and some uncertainties related to the radiation heat transfer processes during temperature measurement that have not been well understood. The objective of this research is to make use of the infrared or thermal imaging system to provide a concise temperature distribution of a methane gas plume presented in the infrared image. However, the current technology in infrared imaging cannot provide the true temperature of a gas plume because the emissivity value is always assumed as unity, and the actual emissivity value of the gas is not integrated in the camera’s algorithm. The visualization of dispersed liquefied natural gas (LNG) vapor from LNG spills on the ground using a midwave thermal camera is presented in this work. Two types of infrared cameras were used: Amber Radiance 1 and GasFindIR, also known in industry as hydrocarbon camera. The infrared images or thermograms show that several factors affecting the temperature measurement are weather conditions, wind rose, atmospheric attenuation due to the presence of other radiation absorbing gases along the optic path, and gas emissivity. Gas emissivity is the main uncertainty in gas temperature measurement using thermal cameras. This research proposed a method to correct the gas temperature measured by a thermal camera by applying the emissivity factor calculated from a theoretical analysis on methane gas emissivity using the band absorption method. The study demonstrates that methane gas emissivity is a strong function of gas temperature; however, the effect of optical depth is insignificant. Because in this work, the infrared camera is used to visualize the LNG vapor, temperature dependence of methane emissivity at temperatures 110−300 K is evaluated and presented in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901340g Exemplaires
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Titre : Thermodynamics model of predicting gas hydrate in porous media based on reaction−adsorption two-step formation mechanism Type de document : texte imprimé Auteurs : Li-Tao Chen, Auteur ; Chang-Yu Sun, Auteur ; Guang-Jin Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 3936–3943 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Thermodynamics Predicting Gas Hydrate Porous Adsorption Résumé : A thermodynamics model is improved to predict the hydrate−water−gas equilibria in micropores based on the reaction−adsorption two-step formation mechanism by considering the effect of capillarity. The interfacial tension values between hydrate and water for different gas species are determined by the Gibbs−Thomson relationship or generalized as a linear function of temperatures. The hydrate phase equilibrium conditions for carbon dioxide, methane, ethane, propane, and (6.7% methane + 2.1% ethane + 91.2% propane) gas mixtures in porous media with different pore diameters predicted by the thermodynamics model developed in this work are equivalent to or superior to those of the traditional van der Waals−Platteeuw type models if the interfacial tension values are fixed. The absolute average deviations for all porous media systems can be decreased to 5.08% after a linear relation of interfacial tension and temperatures are introduced. It was found that the interfacial tension values between hydrate and water are in the magnitude order of propane, ethane, carbon dioxide, and methane, which is related to hydrate structure type and the occupancy of linked cavities for different gas species. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901878p
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3936–3943[article] Thermodynamics model of predicting gas hydrate in porous media based on reaction−adsorption two-step formation mechanism [texte imprimé] / Li-Tao Chen, Auteur ; Chang-Yu Sun, Auteur ; Guang-Jin Chen, Auteur . - 2010 . - pp. 3936–3943.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3936–3943
Mots-clés : Thermodynamics Predicting Gas Hydrate Porous Adsorption Résumé : A thermodynamics model is improved to predict the hydrate−water−gas equilibria in micropores based on the reaction−adsorption two-step formation mechanism by considering the effect of capillarity. The interfacial tension values between hydrate and water for different gas species are determined by the Gibbs−Thomson relationship or generalized as a linear function of temperatures. The hydrate phase equilibrium conditions for carbon dioxide, methane, ethane, propane, and (6.7% methane + 2.1% ethane + 91.2% propane) gas mixtures in porous media with different pore diameters predicted by the thermodynamics model developed in this work are equivalent to or superior to those of the traditional van der Waals−Platteeuw type models if the interfacial tension values are fixed. The absolute average deviations for all porous media systems can be decreased to 5.08% after a linear relation of interfacial tension and temperatures are introduced. It was found that the interfacial tension values between hydrate and water are in the magnitude order of propane, ethane, carbon dioxide, and methane, which is related to hydrate structure type and the occupancy of linked cavities for different gas species. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901878p Exemplaires
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Titre : Pressure drop of structured packing of carbon nanofiber composite Type de document : texte imprimé Auteurs : Yaojie Cao, Auteur ; Ping Li, Auteur ; Jinghong Zhou, Auteur Année de publication : 2010 Article en page(s) : pp. 3944–3951 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Carbon Nanofiber Composite Pressure Structured Packing Résumé : Carbon nanofibers (CNFs) are grown on graphite fiber felt with a desired shape and dimension to form a structured carbon nanofiber composite. This CNF composite has a bimodal porous structure, containing macropores due to the intertexture of graphite fibers and mesopores due to the intertwist of CNFs. The pressure drop of the composite is derived from the convective flow of fluid through the macropores and is independent of the mesopores. Both viscous and turbulent resistance increases with the CNF’s loading. After being wetted with cyclohexane and dried in the air, the CNF’s layer shrinks and becomes smoother, and the composite has a much smaller viscous and turbulent resistance for the fluid. An extended Ergun equation is developed and is shown to be able to predict very well the pressure drop from the structural parameters that are related to the CNF’s loading, i.e., macropore porosity and expanded diameter of the graphite fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020446
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3944–3951[article] Pressure drop of structured packing of carbon nanofiber composite [texte imprimé] / Yaojie Cao, Auteur ; Ping Li, Auteur ; Jinghong Zhou, Auteur . - 2010 . - pp. 3944–3951.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3944–3951
Mots-clés : Carbon Nanofiber Composite Pressure Structured Packing Résumé : Carbon nanofibers (CNFs) are grown on graphite fiber felt with a desired shape and dimension to form a structured carbon nanofiber composite. This CNF composite has a bimodal porous structure, containing macropores due to the intertexture of graphite fibers and mesopores due to the intertwist of CNFs. The pressure drop of the composite is derived from the convective flow of fluid through the macropores and is independent of the mesopores. Both viscous and turbulent resistance increases with the CNF’s loading. After being wetted with cyclohexane and dried in the air, the CNF’s layer shrinks and becomes smoother, and the composite has a much smaller viscous and turbulent resistance for the fluid. An extended Ergun equation is developed and is shown to be able to predict very well the pressure drop from the structural parameters that are related to the CNF’s loading, i.e., macropore porosity and expanded diameter of the graphite fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020446 Exemplaires
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Titre : Developing a cost minimizing power load prediction model for steelwork industries Type de document : texte imprimé Auteurs : Jun-Hyung Ryu, Auteur ; Dong Joon Yoo, Auteur ; In-Beum Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 3952–3956 Langues : Anglais (eng) Mots-clés : Minimizing Power Steelwork Industries Résumé : The key issue of power systems is to match power demand and supply with the minimum gap and delay. In the steelmaking industry that is well-known for intensive power demand, multiple types of power supply sources are thus prepared. One is to use gas turbine generators consuming byproduct gases, another is to purchase power from external electricity companies, and yet another is to use in-house self-generators to prevent any interruptions. Because we have to prepare the power supply before demands are actually realized, the fuels for generators should be purchased based upon a relatively long-term plan, and redundant power should be consumed by being resold or in other ways. It is economically important to predict power load accurately for the profitability of the steelworks. A load prediction model is therefore mathematically formulated as a linear programming (LP) problem with a view to minimizing the overall power cost. A case of an actual steelmaking company in Korea is addressed to illustrate the applicability of the proposed model with some remarks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900227e
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3952–3956[article] Developing a cost minimizing power load prediction model for steelwork industries [texte imprimé] / Jun-Hyung Ryu, Auteur ; Dong Joon Yoo, Auteur ; In-Beum Lee, Auteur . - 2010 . - pp. 3952–3956.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3952–3956
Mots-clés : Minimizing Power Steelwork Industries Résumé : The key issue of power systems is to match power demand and supply with the minimum gap and delay. In the steelmaking industry that is well-known for intensive power demand, multiple types of power supply sources are thus prepared. One is to use gas turbine generators consuming byproduct gases, another is to purchase power from external electricity companies, and yet another is to use in-house self-generators to prevent any interruptions. Because we have to prepare the power supply before demands are actually realized, the fuels for generators should be purchased based upon a relatively long-term plan, and redundant power should be consumed by being resold or in other ways. It is economically important to predict power load accurately for the profitability of the steelworks. A load prediction model is therefore mathematically formulated as a linear programming (LP) problem with a view to minimizing the overall power cost. A case of an actual steelmaking company in Korea is addressed to illustrate the applicability of the proposed model with some remarks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900227e Exemplaires
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Titre : Epoxidation of 2-butene from raffinate 2 feedstock Type de document : texte imprimé Auteurs : Torsten Berndt, Auteur Année de publication : 2010 Article en page(s) : pp 3957–3960 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Epoxidation Butene Raffinate Feedstock Résumé : The gas-phase epoxidation of 2-butene (trans or cis) has been conducted in a flow-through reactor at a pressure of 0.5 bar and a temperature of 325 °C using a N2/O2 mixture as the carrier gas. The primary oxidizing agent in the feed gas is ozone. Selectivity to epoxide (trans- and cis-epoxide in total) of about 90% is observed. Investigations using mixtures of trans-2-butene with 1-butene or n-butane revealed a clearly preferred reaction of trans-2-butene. Kinetic analysis of the overall process yielded ratios for the corresponding rate coefficients of k(trans-2-butene)/k(1-butene) = 5.4−7.2 and k(trans-2-butene)/k(n-butane) 67. A few experiments showed a similar behavior for cis-2-butene. Using raffinate 2 (1-butene, 2-butene, n-butane, and iso-butane) as the feedstock for epoxidation, a selective production of 2-butene oxide (trans/cis mixture) is feasible. Additions of methane (1.7−12.5 vol %), H2O vapor (1.7−4.2 vol %), or CO2 (1.7−25 vol %) in the carrier gas do not influence the epoxidation reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901349n
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp 3957–3960[article] Epoxidation of 2-butene from raffinate 2 feedstock [texte imprimé] / Torsten Berndt, Auteur . - 2010 . - pp 3957–3960.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp 3957–3960
Mots-clés : Epoxidation Butene Raffinate Feedstock Résumé : The gas-phase epoxidation of 2-butene (trans or cis) has been conducted in a flow-through reactor at a pressure of 0.5 bar and a temperature of 325 °C using a N2/O2 mixture as the carrier gas. The primary oxidizing agent in the feed gas is ozone. Selectivity to epoxide (trans- and cis-epoxide in total) of about 90% is observed. Investigations using mixtures of trans-2-butene with 1-butene or n-butane revealed a clearly preferred reaction of trans-2-butene. Kinetic analysis of the overall process yielded ratios for the corresponding rate coefficients of k(trans-2-butene)/k(1-butene) = 5.4−7.2 and k(trans-2-butene)/k(n-butane) 67. A few experiments showed a similar behavior for cis-2-butene. Using raffinate 2 (1-butene, 2-butene, n-butane, and iso-butane) as the feedstock for epoxidation, a selective production of 2-butene oxide (trans/cis mixture) is feasible. Additions of methane (1.7−12.5 vol %), H2O vapor (1.7−4.2 vol %), or CO2 (1.7−25 vol %) in the carrier gas do not influence the epoxidation reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901349n Exemplaires
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Titre : Photocatalytic degradation of nitrobenzene in an aqueous system by transition-metal-exchanged ETS-10 zeolites Type de document : texte imprimé Auteurs : Praveen K. Surolia, Auteur ; Rajesh J. Tayade, Auteur ; Raksh V. Jasra, Auteur Année de publication : 2010 Article en page(s) : pp 3961–3966 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic Nitrobenzene Metal-Exchanged Zeolites Résumé : Engelhard titanosilicate ETS-10 was synthesized using Degussa P25 as the titanium source. Metal-exchanged microporous titanium silicate M−ETS-10 (M = Fe, Co, Ni, Cu, and Ag) samples were prepared by ion exchange with respective metal salt solutions. The synthesized samples were characterized by powder X-ray diffraction, BET surface area, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and UV−vis diffuse reflectance measurements (DRS). The photocatalytic activity of these samples was investigated for the decomposition of nitrobenzene (NB). The pristine ETS-10 and transition-metal-ion-exchanged ETS-10 samples were found to be active photocatalysts that can decompose nitrobenzene under UV irradiation. Results demonstrated that silver-ion-exchanged ETS-10 shows the highest photocatalytic activity for degradation and mineralization of nitrobenzene. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901603k
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp 3961–3966[article] Photocatalytic degradation of nitrobenzene in an aqueous system by transition-metal-exchanged ETS-10 zeolites [texte imprimé] / Praveen K. Surolia, Auteur ; Rajesh J. Tayade, Auteur ; Raksh V. Jasra, Auteur . - 2010 . - pp 3961–3966.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp 3961–3966
Mots-clés : Photocatalytic Nitrobenzene Metal-Exchanged Zeolites Résumé : Engelhard titanosilicate ETS-10 was synthesized using Degussa P25 as the titanium source. Metal-exchanged microporous titanium silicate M−ETS-10 (M = Fe, Co, Ni, Cu, and Ag) samples were prepared by ion exchange with respective metal salt solutions. The synthesized samples were characterized by powder X-ray diffraction, BET surface area, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and UV−vis diffuse reflectance measurements (DRS). The photocatalytic activity of these samples was investigated for the decomposition of nitrobenzene (NB). The pristine ETS-10 and transition-metal-ion-exchanged ETS-10 samples were found to be active photocatalysts that can decompose nitrobenzene under UV irradiation. Results demonstrated that silver-ion-exchanged ETS-10 shows the highest photocatalytic activity for degradation and mineralization of nitrobenzene. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901603k Exemplaires
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Titre : Retrofitting heat exchanger networks based on simple pinch analysis Type de document : texte imprimé Auteurs : Bao-Hong Li, Auteur Année de publication : 2010 Article en page(s) : pp. 3967–3971 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Retrofitting Heat Exchanger Networks Based Pinch Analysis Résumé : It has been well-established that the energy and capital costs of a heat exchanger network are both dependent upon the minimum allowable temperature approach ΔTmin. As a result of the rapidly growing oil prices in recent years, there appears to be an urgent need to retrofit the existing “optimal” networks so as to reduce the current utility consumption rates with smaller ΔTmin values. A simple pinch-based approach is proposed here to accomplish this task while keeping additional capital investment to a reasonable level. In particular, every cross-pinch match is removed, and its heat loads on the hot and cold streams are both divided into two according to the pinch temperatures. At either side of the pinch, the divided heat loads on each stream are combined and then matched according to a systematic procedure derived from simple pinch analysis. Two examples are provided to illustrate this procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016607
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3967–3971[article] Retrofitting heat exchanger networks based on simple pinch analysis [texte imprimé] / Bao-Hong Li, Auteur . - 2010 . - pp. 3967–3971.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3967–3971
Mots-clés : Retrofitting Heat Exchanger Networks Based Pinch Analysis Résumé : It has been well-established that the energy and capital costs of a heat exchanger network are both dependent upon the minimum allowable temperature approach ΔTmin. As a result of the rapidly growing oil prices in recent years, there appears to be an urgent need to retrofit the existing “optimal” networks so as to reduce the current utility consumption rates with smaller ΔTmin values. A simple pinch-based approach is proposed here to accomplish this task while keeping additional capital investment to a reasonable level. In particular, every cross-pinch match is removed, and its heat loads on the hot and cold streams are both divided into two according to the pinch temperatures. At either side of the pinch, the divided heat loads on each stream are combined and then matched according to a systematic procedure derived from simple pinch analysis. Two examples are provided to illustrate this procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016607 Exemplaires
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Titre : New method of catalytic cracking of hydrocarbon fuels using a highly dispersed nano-HZSM-5 catalyst Type de document : texte imprimé Auteurs : Shiguo Bao, Auteur ; Guozhu Liu, Auteur ; Xiangwen Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 3972–3975 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Catalytic Cracking Hydrocarbon Fuels Highly Dispersed Nano Résumé : A pseudohomogeneous method of catalytic cracking of hydrocarbon fuels using a highly dispersed nano-HZSM-5 catalyst is developed. Hydrophilic nano-HZSM-5 is transformed into a hydrophobic form via organic silanization of the zeolite surface, which makes it dispersible in a model endothermic fuel such as n-dodecane. Compared with thermal cracking, catalytic cracking of n-dodecane with highly dispersed nano-HZSM-5 catalyst exhibits remarkably enhanced conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901801q
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3972–3975[article] New method of catalytic cracking of hydrocarbon fuels using a highly dispersed nano-HZSM-5 catalyst [texte imprimé] / Shiguo Bao, Auteur ; Guozhu Liu, Auteur ; Xiangwen Zhang, Auteur . - 2010 . - pp. 3972–3975.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3972–3975
Mots-clés : Catalytic Cracking Hydrocarbon Fuels Highly Dispersed Nano Résumé : A pseudohomogeneous method of catalytic cracking of hydrocarbon fuels using a highly dispersed nano-HZSM-5 catalyst is developed. Hydrophilic nano-HZSM-5 is transformed into a hydrophobic form via organic silanization of the zeolite surface, which makes it dispersible in a model endothermic fuel such as n-dodecane. Compared with thermal cracking, catalytic cracking of n-dodecane with highly dispersed nano-HZSM-5 catalyst exhibits remarkably enhanced conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901801q Exemplaires
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Titre : Ice−clathrate hydrate−gas phase equilibria for air, oxygen, nitrogen, carbon monoxide, methane, or ethane + water system Type de document : texte imprimé Auteurs : Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur Année de publication : 2010 Article en page(s) : pp. 3976–3979 Note générale : Industrail Chemistry Langues : Anglais (eng) Mots-clés : ice clathrate hydrate− gas air oxygen nitrogen carbon monoxide methane ethane Résumé : In this work, we report ice−clathrate hydrate−gas equilibrium data (dissociation data) for the air, oxygen, nitrogen, carbon monoxide, methane, or ethane + water system. The equilibrium data for methane and ethane clathrate hydrates are compared with the equilibrium data reported in the literature to demonstrate the reliability of the isothermal pressure-search method used in our measurements. The equilibrium data generated for nitrogen and oxygen clathrate hydrates are compared with few sets of experimental data reported in the literature. It is shown that the existing ice−clathrate hydrate−gas equilibrium data reported in the literature for the nitrogen or oxygen + water system are not reliable. A comparison is finally made on the equilibrium conditions of air, oxygen, nitrogen, and carbon monoxide clathrate hydrates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901820u
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3976–3979[article] Ice−clathrate hydrate−gas phase equilibria for air, oxygen, nitrogen, carbon monoxide, methane, or ethane + water system [texte imprimé] / Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur . - 2010 . - pp. 3976–3979.
Industrail Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3976–3979
Mots-clés : ice clathrate hydrate− gas air oxygen nitrogen carbon monoxide methane ethane Résumé : In this work, we report ice−clathrate hydrate−gas equilibrium data (dissociation data) for the air, oxygen, nitrogen, carbon monoxide, methane, or ethane + water system. The equilibrium data for methane and ethane clathrate hydrates are compared with the equilibrium data reported in the literature to demonstrate the reliability of the isothermal pressure-search method used in our measurements. The equilibrium data generated for nitrogen and oxygen clathrate hydrates are compared with few sets of experimental data reported in the literature. It is shown that the existing ice−clathrate hydrate−gas equilibrium data reported in the literature for the nitrogen or oxygen + water system are not reliable. A comparison is finally made on the equilibrium conditions of air, oxygen, nitrogen, and carbon monoxide clathrate hydrates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901820u Exemplaires
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Titre : Feed-stage multiplicity in multicomponent distillation Type de document : texte imprimé Auteurs : William L. Luyben, Auteur Année de publication : 2010 Article en page(s) : pp. 3980–3982 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Feed Multicomponent Distillation Résumé : Finding the optimum feed-stage location in distillation design usually is achieved by determining what location minimizes reboiler energy consumption. There is a minimum in a plot of energy versus feed stage in ideal distillation columns. However, in multicomponent systems, multiple steady states may occur as feed-stage location is varied. This note presents a numerical example of this phenomenon. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001108
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3980–3982[article] Feed-stage multiplicity in multicomponent distillation [texte imprimé] / William L. Luyben, Auteur . - 2010 . - pp. 3980–3982.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3980–3982
Mots-clés : Feed Multicomponent Distillation Résumé : Finding the optimum feed-stage location in distillation design usually is achieved by determining what location minimizes reboiler energy consumption. There is a minimum in a plot of energy versus feed stage in ideal distillation columns. However, in multicomponent systems, multiple steady states may occur as feed-stage location is varied. This note presents a numerical example of this phenomenon. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001108 Exemplaires
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Titre : Polysulfide distribution during kraft pulping Type de document : texte imprimé Auteurs : Sujit Banerjee, Auteur ; Yang, Rallming, Auteur Année de publication : 2010 Article en page(s) : pp. 3983–3985 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Polysulfi Kraft Pulping Pul Résumé : Polysulfides increase yield from kraft pulping by selectively oxidizing the reducing end groups of the polysaccharides thereby protecting them from hydrolysis. The principal polysulfide homologue formed in white liquor after addition of elemental sulfur was found to be the S22− species. Analysis of both cooking liquor and wood chips during early cooking suggests that the polysulfide present in the chips degrades more slowly than the fraction dissolved in the bulk liquor. The alkalinity inside the chips is lower than that in the bulk liquor. We propose that the rate of degradation of the polysulfides contained within the chip is correspondingly reduced. As pulping proceeds and the structure of the chips open up, the diffusion barrier across the chip is reduced and the polysulfide concentration in the chip and in the bulk liquor begins to even out. It follows that pre-equilibration of wood chips with polysulfide before pulping may reduce the optimum polysulfide dose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100176x
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3983–3985[article] Polysulfide distribution during kraft pulping [texte imprimé] / Sujit Banerjee, Auteur ; Yang, Rallming, Auteur . - 2010 . - pp. 3983–3985.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3983–3985
Mots-clés : Polysulfi Kraft Pulping Pul Résumé : Polysulfides increase yield from kraft pulping by selectively oxidizing the reducing end groups of the polysaccharides thereby protecting them from hydrolysis. The principal polysulfide homologue formed in white liquor after addition of elemental sulfur was found to be the S22− species. Analysis of both cooking liquor and wood chips during early cooking suggests that the polysulfide present in the chips degrades more slowly than the fraction dissolved in the bulk liquor. The alkalinity inside the chips is lower than that in the bulk liquor. We propose that the rate of degradation of the polysulfides contained within the chip is correspondingly reduced. As pulping proceeds and the structure of the chips open up, the diffusion barrier across the chip is reduced and the polysulfide concentration in the chip and in the bulk liquor begins to even out. It follows that pre-equilibration of wood chips with polysulfide before pulping may reduce the optimum polysulfide dose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100176x Exemplaires
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Titre : Cigarette butts and their application in corrosion inhibition for N80 steel at 90 °C in a hydrochloric acid solution Type de document : texte imprimé Auteurs : Jun Zhao, Auteur ; Ningsheng Zhang, Auteur ; Chengtun Qu, Auteur Année de publication : 2010 Article en page(s) : pp. 3986–3991 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Cigarette Corrosion Inhibition Steel Hydrochloric Acid Résumé : Cigarette butts, one of the most ubiquitous forms of garbage in the world, need to be recycled because their toxicity can kill saltwater and freshwater fish. In this study, the cigarette butts are applied as corrosion inhibitors for N80 steel at 90 °C in hydrochloric acid. Weight loss and electrochemical techniques are used to evaluate the corrosion inhibitive effect of cigarette butt water extracts. Results show that the inhibition efficiencies arrive at 94.6% and 91.7% in 10% and 15% (wt %) HCl solution, respectively, by adding 5% (wt %) inhibitor. In 20% HCl solution, they show a maximum inhibition efficiency of 88.4% by adding 10% inhibitor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100168s
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3986–3991[article] Cigarette butts and their application in corrosion inhibition for N80 steel at 90 °C in a hydrochloric acid solution [texte imprimé] / Jun Zhao, Auteur ; Ningsheng Zhang, Auteur ; Chengtun Qu, Auteur . - 2010 . - pp. 3986–3991.
Industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3986–3991
Mots-clés : Cigarette Corrosion Inhibition Steel Hydrochloric Acid Résumé : Cigarette butts, one of the most ubiquitous forms of garbage in the world, need to be recycled because their toxicity can kill saltwater and freshwater fish. In this study, the cigarette butts are applied as corrosion inhibitors for N80 steel at 90 °C in hydrochloric acid. Weight loss and electrochemical techniques are used to evaluate the corrosion inhibitive effect of cigarette butt water extracts. Results show that the inhibition efficiencies arrive at 94.6% and 91.7% in 10% and 15% (wt %) HCl solution, respectively, by adding 5% (wt %) inhibitor. In 20% HCl solution, they show a maximum inhibition efficiency of 88.4% by adding 10% inhibitor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100168s Exemplaires
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