[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp 8334–8339

Titre :	Realistic models for distillation columns with partial condensers producing both liquid and vapor products
Type de document :	texte imprimé
Auteurs :	William L. Luyben, Auteur
Année de publication :	2012
Article en page(s) :	pp 8334–8339
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Distillation  columns  Liquid  Vapor
Résumé :	Distillation columns frequently produce both vapor and liquid distillate product streams from the reflux drum when the feed stream contains small amounts of light components that would require high pressures or low temperatures if a total condenser were used to completely condense the overhead product. Since removing heat using cooling water in the condenser is much less expensive than using refrigeration, many columns are designed to operate with reflux-drum temperatures of about 120 °F so that cooling water at 90 °F can be used. Fixing reflux-drum temperature and selecting a reasonable pressure determines the split between the amount of vapor product and the amount of liquid product. In the operation of these systems, we usually want to condense as much as possible so as to minimize compression costs of dealing with the vapor product. Therefore the flow rate of cooling water should be maximized. This paper demonstrates a realistic way to model a partial-condenser distillation system using Aspen simulation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300818b

[article] Realistic models for distillation columns with partial condensers producing both liquid and vapor products [texte imprimé] / William L. Luyben, Auteur . - 2012 . - pp 8334–8339.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp 8334–8339

Mots-clés :	Distillation  columns  Liquid  Vapor
Résumé :	Distillation columns frequently produce both vapor and liquid distillate product streams from the reflux drum when the feed stream contains small amounts of light components that would require high pressures or low temperatures if a total condenser were used to completely condense the overhead product. Since removing heat using cooling water in the condenser is much less expensive than using refrigeration, many columns are designed to operate with reflux-drum temperatures of about 120 °F so that cooling water at 90 °F can be used. Fixing reflux-drum temperature and selecting a reasonable pressure determines the split between the amount of vapor product and the amount of liquid product. In the operation of these systems, we usually want to condense as much as possible so as to minimize compression costs of dealing with the vapor product. Therefore the flow rate of cooling water should be maximized. This paper demonstrates a realistic way to model a partial-condenser distillation system using Aspen simulation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300818b

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8326–8333

Titre :	Integrated process configuration for high - temperature sulfur mitigation during biomass conversion via indirect gasification
Type de document :	texte imprimé
Auteurs :	Abhijit Dutta, Auteur ; Singfoong Cheah, Auteur ; Richard Bain, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8326–8333
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biomass  Gasification
Résumé :	Sulfur present in biomass often causes catalyst deactivation during downstream operations after gasification. Early removal of sulfur from the syngas stream post-gasification is possible via process rearrangements and can be beneficial for maintaining a low-sulfur environment for all downstream operations. High-temperature sulfur sorbents have superior performance and capacity under drier syngas conditions. The reconfigured process discussed in this paper is comprised of indirect biomass gasification using dry recycled gas from downstream operations, which produces a drier syngas stream and, consequently, more-efficient sulfur removal at high temperatures using regenerable sorbents. A combination of experimental results from NREL’s fluidizable Ni-based reforming catalyst, fluidizable Mn-based sulfur sorbent, and process modeling information show that using a coupled process of dry gasification with high-temperature sulfur removal can improve the performance of Ni-based reforming catalysts significantly.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202797s

[article] Integrated process configuration for high - temperature sulfur mitigation during biomass conversion via indirect gasification [texte imprimé] / Abhijit Dutta, Auteur ; Singfoong Cheah, Auteur ; Richard Bain, Auteur . - 2012 . - pp. 8326–8333.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8326–8333

Mots-clés :	Biomass  Gasification
Résumé :	Sulfur present in biomass often causes catalyst deactivation during downstream operations after gasification. Early removal of sulfur from the syngas stream post-gasification is possible via process rearrangements and can be beneficial for maintaining a low-sulfur environment for all downstream operations. High-temperature sulfur sorbents have superior performance and capacity under drier syngas conditions. The reconfigured process discussed in this paper is comprised of indirect biomass gasification using dry recycled gas from downstream operations, which produces a drier syngas stream and, consequently, more-efficient sulfur removal at high temperatures using regenerable sorbents. A combination of experimental results from NREL’s fluidizable Ni-based reforming catalyst, fluidizable Mn-based sulfur sorbent, and process modeling information show that using a coupled process of dry gasification with high-temperature sulfur removal can improve the performance of Ni-based reforming catalysts significantly.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202797s

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8315–8325

Titre :	Determination and chemical modeling of phase equilibria for the glycine – KCl – NaCl – H2O system and its application to produce crystals with anticaking characteristics
Type de document :	texte imprimé
Auteurs :	Wencheng Gao, Auteur ; Zhibao Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8315–8325
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Phase  equilibria  Crystals
Résumé :	The phase equilibria of the glycine–KCl–NaCl–H2O system were determined in the concentrations up to 3.33 mol·kg–1 over the temperature range from 283.2 to 363.2 K using a dynamic method. A rigorous chemical model for the glycine–KCl–NaCl–H2O system was established by the Pitzer model with the help of an OLI platform. With the equilibrium constants of dissociation reactions obtained by standard-state thermodynamic data, the new Pitzer model parameters were harvested by regressing solubility of the system. These newly obtained parameters were used to accurately predict the multiple saturated points at the temperature range from 283.2 to 363.2 K. The phase behavior of the ternary glycine–KCl–H2O and glycine–NaCl–H2O system at 298.2 and 343.2 K were successfully visualized with lucidity on an equilateral triangle. To investigate the effect of glycine on the morphology of KCl, the KCl crystals were produced from glycine solution with different concentration (17–25% w/v) by evaporation at ambient temperature. The glycine (25% w/v)-modified KCl crystal changed its morphology from native cubic to hexagonal prism form with the angle of repose from 32° to 23.8–25.8°, indicating a good flowability and anticaking characteristics. Finally, KCl supersaturation variation with evaporation time was simulated with aid of the chemical model established in present study to elucidate the influence of glycine concentration on the anticaking characteristics of KCl crystal. All the results generated from this study will provide the fundamentals for industrial application to produce crystals with anticaking characteristics.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300787k

[article] Determination and chemical modeling of phase equilibria for the glycine – KCl – NaCl – H2O system and its application to produce crystals with anticaking characteristics [texte imprimé] / Wencheng Gao, Auteur ; Zhibao Li, Auteur . - 2012 . - pp. 8315–8325.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8315–8325

Mots-clés :	Phase  equilibria  Crystals
Résumé :	The phase equilibria of the glycine–KCl–NaCl–H2O system were determined in the concentrations up to 3.33 mol·kg–1 over the temperature range from 283.2 to 363.2 K using a dynamic method. A rigorous chemical model for the glycine–KCl–NaCl–H2O system was established by the Pitzer model with the help of an OLI platform. With the equilibrium constants of dissociation reactions obtained by standard-state thermodynamic data, the new Pitzer model parameters were harvested by regressing solubility of the system. These newly obtained parameters were used to accurately predict the multiple saturated points at the temperature range from 283.2 to 363.2 K. The phase behavior of the ternary glycine–KCl–H2O and glycine–NaCl–H2O system at 298.2 and 343.2 K were successfully visualized with lucidity on an equilateral triangle. To investigate the effect of glycine on the morphology of KCl, the KCl crystals were produced from glycine solution with different concentration (17–25% w/v) by evaporation at ambient temperature. The glycine (25% w/v)-modified KCl crystal changed its morphology from native cubic to hexagonal prism form with the angle of repose from 32° to 23.8–25.8°, indicating a good flowability and anticaking characteristics. Finally, KCl supersaturation variation with evaporation time was simulated with aid of the chemical model established in present study to elucidate the influence of glycine concentration on the anticaking characteristics of KCl crystal. All the results generated from this study will provide the fundamentals for industrial application to produce crystals with anticaking characteristics.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300787k

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8308-8314

Titre :	Preparation and performance of antifouling PVC / CPVC blend ultrafiltration membranes
Type de document :	texte imprimé
Auteurs :	Jiazhen Liu, Auteur ; Su, Yanlei, Auteur ; Jinming Peng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8308-8314
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Membrane  separation  Ultrafiltration  Preparation
Résumé :	Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) were used as membrane materials to fabricate blend ultrafiltration membranes. Polyethylene glycol (PEG2000) and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (Pluronic F127) were used as both pore forming agent and surface modifier to improve the permeability. The advantage of amphiphilic Pluronic F127 is that it enables higher ―CH2―CH2―O― segment coverage on the membrane surfaces. The increase of CPVC proportion in membrane materials could improve the water fluxes of PVC/CPVC blend membranes with the slight change of protein rejection ratios. All the PVC/CPVC blend membranes with an additive of Pluronic F 127 have excellent antifouling property. The blend method is an appropriate way to prepare new antifouling PVC/ CPVC ultrafiltration membranes which have lower cost and better performance.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029666

[article] Preparation and performance of antifouling PVC / CPVC blend ultrafiltration membranes [texte imprimé] / Jiazhen Liu, Auteur ; Su, Yanlei, Auteur ; Jinming Peng, Auteur . - 2012 . - pp. 8308-8314.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8308-8314

Mots-clés :	Membrane  separation  Ultrafiltration  Preparation
Résumé :	Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) were used as membrane materials to fabricate blend ultrafiltration membranes. Polyethylene glycol (PEG2000) and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (Pluronic F127) were used as both pore forming agent and surface modifier to improve the permeability. The advantage of amphiphilic Pluronic F127 is that it enables higher ―CH2―CH2―O― segment coverage on the membrane surfaces. The increase of CPVC proportion in membrane materials could improve the water fluxes of PVC/CPVC blend membranes with the slight change of protein rejection ratios. All the PVC/CPVC blend membranes with an additive of Pluronic F 127 have excellent antifouling property. The blend method is an appropriate way to prepare new antifouling PVC/ CPVC ultrafiltration membranes which have lower cost and better performance.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029666

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8302–8307

Titre :	Liquid–Liquid Phase Equilibria of Systems of Palm and Soya Biodiesels : Experimental and Modeling
Type de document :	texte imprimé
Auteurs :	Masoume Rostami, Auteur ; Sona Raeissi, Auteur ; Maziyar Mahmoudi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8302–8307
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling  Phase  equilibrium  Liquid  liquid  equilibrium
Résumé :	Liquid–liquid phase equilibria of two systems of concern in the biodiesel production process are determined experimentally. The first system is the binary mixture of water + biodiesel within a temperature range of 297.2 to 333.2 K, in order to determine water solubilities in two biodiesels prepared from palm and soya oil. The experimental results showed that water solubilities were limited to values below 0.05 mol % and that the solubility increased with increasing temperature and biodiesel unsaturation. Next, the phase diagrams of ternary mixtures of glycerol + methanol + mentioned biodiesels were determined at three temperatures (293.2, 303.2, and 313.2 K). The reliability of the experimental data of tie lines was ascertained using the Othmer-Tobias relation. The UNIQUAC model was then used to model both the binary and ternary experimental data. Results showed the suitability of this model in correlating the phase behavior of such systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029665

[article] Liquid–Liquid Phase Equilibria of Systems of Palm and Soya Biodiesels : Experimental and Modeling [texte imprimé] / Masoume Rostami, Auteur ; Sona Raeissi, Auteur ; Maziyar Mahmoudi, Auteur . - 2012 . - pp. 8302–8307.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8302–8307

Mots-clés :	Modeling  Phase  equilibrium  Liquid  liquid  equilibrium
Résumé :	Liquid–liquid phase equilibria of two systems of concern in the biodiesel production process are determined experimentally. The first system is the binary mixture of water + biodiesel within a temperature range of 297.2 to 333.2 K, in order to determine water solubilities in two biodiesels prepared from palm and soya oil. The experimental results showed that water solubilities were limited to values below 0.05 mol % and that the solubility increased with increasing temperature and biodiesel unsaturation. Next, the phase diagrams of ternary mixtures of glycerol + methanol + mentioned biodiesels were determined at three temperatures (293.2, 303.2, and 313.2 K). The reliability of the experimental data of tie lines was ascertained using the Othmer-Tobias relation. The UNIQUAC model was then used to model both the binary and ternary experimental data. Results showed the suitability of this model in correlating the phase behavior of such systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029665

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8293–8301

Titre :	Biobutanol recovery using nonfluorinated task - specific ionic liquids
Type de document :	texte imprimé
Auteurs :	Lesly Y. Garcia-Chavez, Auteur ; Christian M. Garsia, Auteur ; Boelo Schuur, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8293–8301
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biobutanol  Nonfluorinated  Ionic  liquids
Résumé :	Biobutanol has received major attention as an alternative for and additive to fossil fuels. Biobutanol produced via fermentation is hampered by low butanol concentrations in the fermentation broth. An efficient separation process is required to make biobutanol production economically viable. In this work, liquid–liquid extraction of butanol from water, employing nonfluorinated task-specific ionic liquids (TSILs) has been evaluated against distillation and extraction with conventional solvents. Experimental data for the equilibrium distribution ratios of butanol and water were used in a conceptual process design study to find the most promising solvent. The results show that the IL with the best distribution coefficient and very high selectivity was [TOAMNaph] (DBuOH = 21, S = 274), performing much better than the benchmark solvent oleyl alcohol (DBuOH = 3.42, S = 192). The conceptual design study showed that butanol extraction with [TOAMNaph] requires 73% less energy than in conventional distillation (5.65 MJ/kg BuOH vs 21.3 MJ/kg for distillation).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201855h

[article] Biobutanol recovery using nonfluorinated task - specific ionic liquids [texte imprimé] / Lesly Y. Garcia-Chavez, Auteur ; Christian M. Garsia, Auteur ; Boelo Schuur, Auteur . - 2012 . - pp. 8293–8301.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8293–8301

Mots-clés :	Biobutanol  Nonfluorinated  Ionic  liquids
Résumé :	Biobutanol has received major attention as an alternative for and additive to fossil fuels. Biobutanol produced via fermentation is hampered by low butanol concentrations in the fermentation broth. An efficient separation process is required to make biobutanol production economically viable. In this work, liquid–liquid extraction of butanol from water, employing nonfluorinated task-specific ionic liquids (TSILs) has been evaluated against distillation and extraction with conventional solvents. Experimental data for the equilibrium distribution ratios of butanol and water were used in a conceptual process design study to find the most promising solvent. The results show that the IL with the best distribution coefficient and very high selectivity was [TOAMNaph] (DBuOH = 21, S = 274), performing much better than the benchmark solvent oleyl alcohol (DBuOH = 3.42, S = 192). The conceptual design study showed that butanol extraction with [TOAMNaph] requires 73% less energy than in conventional distillation (5.65 MJ/kg BuOH vs 21.3 MJ/kg for distillation).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201855h

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8286–8292

Titre :	Adsorption of four representative biological compounds onto graphite nanofibers
Type de document :	texte imprimé
Auteurs :	Dorothy W. Skaf, Auteur ; Michael A. Smith, Auteur ; Kevin C. Brodwater, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8286–8292
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption  Nanofibers
Résumé :	The present study investigates the adsorption of four compounds important in carbon adsorption hemoperfusion. Graphite nanofibers (GNFs) having different carbon plane orientations have structural features that make them potentially attractive in this application compared to activated carbon. Generally, adsorption capacity increased in the order of ribbon > herringbone > platelet fiber types. All fibers were poor adsorbents for creatinine. Herringbone and platelet fibers had sorption capacities less than 25% of activated carbon for all adsorbates on a mass basis. Except for vitamin B12, behavior of ribbon fibers was similar; vitamin B12 adsorption was nearly 50% greater than activated carbon on a mass basis. In contrast, on the basis of surface area, all of the fibers were comparable to or outperformed activated carbon for the adsorption of all adsorbates. This suggests that in addition to BET surface area, interactions between adsorbate and exposed basal planes in carbon are important in determining adsorption capacity. Chemical treatment with hydrochloric acid or with urea followed by thermal treatment did not significantly change the fiber surface area, micropore volume, or equilibrium adsorption. Nitric acid treatment of herringbone and ribbon fibers slightly decreased the surface area but did not enhance adsorption, whereas this treatment degraded platelet fibers.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201788j

[article] Adsorption of four representative biological compounds onto graphite nanofibers [texte imprimé] / Dorothy W. Skaf, Auteur ; Michael A. Smith, Auteur ; Kevin C. Brodwater, Auteur . - 2012 . - pp. 8286–8292.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8286–8292

Mots-clés :	Adsorption  Nanofibers
Résumé :	The present study investigates the adsorption of four compounds important in carbon adsorption hemoperfusion. Graphite nanofibers (GNFs) having different carbon plane orientations have structural features that make them potentially attractive in this application compared to activated carbon. Generally, adsorption capacity increased in the order of ribbon > herringbone > platelet fiber types. All fibers were poor adsorbents for creatinine. Herringbone and platelet fibers had sorption capacities less than 25% of activated carbon for all adsorbates on a mass basis. Except for vitamin B12, behavior of ribbon fibers was similar; vitamin B12 adsorption was nearly 50% greater than activated carbon on a mass basis. In contrast, on the basis of surface area, all of the fibers were comparable to or outperformed activated carbon for the adsorption of all adsorbates. This suggests that in addition to BET surface area, interactions between adsorbate and exposed basal planes in carbon are important in determining adsorption capacity. Chemical treatment with hydrochloric acid or with urea followed by thermal treatment did not significantly change the fiber surface area, micropore volume, or equilibrium adsorption. Nitric acid treatment of herringbone and ribbon fibers slightly decreased the surface area but did not enhance adsorption, whereas this treatment degraded platelet fibers.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201788j

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8273-8285

Titre :	Comparative performance analysis of coordinated model predictive control schemes in the presence of model – plant mismatch
Type de document :	texte imprimé
Auteurs :	Abhay Anand, Auteur ; Lakshminarayanan Samavedham, Auteur ; Sitanandam Sundaramoorthy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8273-8285
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Predictive  control  Modeling
Résumé :	Large-scale systems are formed by the interconnection of several subsystems, whose different spatial and temporal characteristics make them significantly heterogeneous. The optimal management of such systems must generally deal not only with issues related to large dimensionality and strong nonlinearity, but also with the presence of several interactions between the subsystems, which have a significant influence on the local control decisions and the overall system optimality. For such large-scale systems, model predictive control (MPC) is an attractive control strategy and can be implemented in centralized or decentralized configurations. It has been shown that, to achieve a flexible and reliable control structure with optimum overall system performance, individual decentralized controllers have to be coordinated and driven toward the performance of a centralized controller. In this work, three coordination strategies that have been reported in the literature, viz., communication based coordination, cooperation based coordination, and price driven coordination, are evaluated for controlling multivariable processes. These three strategies have been evaluated on a benchmark chemical engineering system and on a quadruple tank system (via simulations), on the basis of their robustness, stability, and performance in comparison to that of a centralized MPC implementation. The ability to deal with a variety of model uncertainties and the coordination between the controllers within and across a hierarchy are some important aspects that have been investigated.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029662

[article] Comparative performance analysis of coordinated model predictive control schemes in the presence of model – plant mismatch [texte imprimé] / Abhay Anand, Auteur ; Lakshminarayanan Samavedham, Auteur ; Sitanandam Sundaramoorthy, Auteur . - 2012 . - pp. 8273-8285.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8273-8285

Mots-clés :	Predictive  control  Modeling
Résumé :	Large-scale systems are formed by the interconnection of several subsystems, whose different spatial and temporal characteristics make them significantly heterogeneous. The optimal management of such systems must generally deal not only with issues related to large dimensionality and strong nonlinearity, but also with the presence of several interactions between the subsystems, which have a significant influence on the local control decisions and the overall system optimality. For such large-scale systems, model predictive control (MPC) is an attractive control strategy and can be implemented in centralized or decentralized configurations. It has been shown that, to achieve a flexible and reliable control structure with optimum overall system performance, individual decentralized controllers have to be coordinated and driven toward the performance of a centralized controller. In this work, three coordination strategies that have been reported in the literature, viz., communication based coordination, cooperation based coordination, and price driven coordination, are evaluated for controlling multivariable processes. These three strategies have been evaluated on a benchmark chemical engineering system and on a quadruple tank system (via simulations), on the basis of their robustness, stability, and performance in comparison to that of a centralized MPC implementation. The ability to deal with a variety of model uncertainties and the coordination between the controllers within and across a hierarchy are some important aspects that have been investigated.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029662

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8262-8272

Titre :	Isothermal Crystallization Behavior of Biodegradable P(BS-b-PEGS) Multiblock Copolymers
Type de document :	texte imprimé
Auteurs :	Xi Lu, Auteur ; Jian-Bing Zeng, Auteur ; Cai-Li Huang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8262-8272
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization
Résumé :	Biodegradable multiblock copolymers poly(butylene succinate-b-poly(ethylene glycol) succinate) (P(BS-b-PEGS)) were prepared by direct polycondensation. The thermal and crystallization behavior of P(BS-b-PEGS) with weight fraction of PEGS component from 6 to 26 wt % were comparatively investigated with those of neat poly(butylene succinate) (PBS) by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and polarized optical microscopy (POM). P(BS-b-PEGS) showed the same crystal structure as neat PBS, but the degree of crystallinity of copolymers was lower than that of neat PBS and decreased with increase in PEGS content The isothermal crystallization kinetics study suggests that incorporation of PEGS component did not change the crystallization mechanism, but reduced the crystallization rate of the samples, and that increasing crystallization temperature decreased the crystallization rate of all the samples. The spherulites of neat PBS and P(BS-b-PEGS) showed banded morphologies. The spherulitic growth rate of the samples also decreased with increase of PEGS content and crystallization temperature. A transition from crystallization regime II to III occurred for all the samples, and the transition shifted to lower temperatures with increase in PEGS content.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029661

[article] Isothermal Crystallization Behavior of Biodegradable P(BS-b-PEGS) Multiblock Copolymers [texte imprimé] / Xi Lu, Auteur ; Jian-Bing Zeng, Auteur ; Cai-Li Huang, Auteur . - 2012 . - pp. 8262-8272.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8262-8272

Mots-clés :	Crystallization
Résumé :	Biodegradable multiblock copolymers poly(butylene succinate-b-poly(ethylene glycol) succinate) (P(BS-b-PEGS)) were prepared by direct polycondensation. The thermal and crystallization behavior of P(BS-b-PEGS) with weight fraction of PEGS component from 6 to 26 wt % were comparatively investigated with those of neat poly(butylene succinate) (PBS) by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and polarized optical microscopy (POM). P(BS-b-PEGS) showed the same crystal structure as neat PBS, but the degree of crystallinity of copolymers was lower than that of neat PBS and decreased with increase in PEGS content The isothermal crystallization kinetics study suggests that incorporation of PEGS component did not change the crystallization mechanism, but reduced the crystallization rate of the samples, and that increasing crystallization temperature decreased the crystallization rate of all the samples. The spherulites of neat PBS and P(BS-b-PEGS) showed banded morphologies. The spherulitic growth rate of the samples also decreased with increase of PEGS content and crystallization temperature. A transition from crystallization regime II to III occurred for all the samples, and the transition shifted to lower temperatures with increase in PEGS content.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029661

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8253-8261

Titre :	Studies on mechanical poperties, thermal degradation, and combustion behaviors of poly(1,4 - butylene terephthalate)/glass fiber/cerium hypophosphite composites
Type de document :	texte imprimé
Auteurs :	Wei Yang, Auteur ; Ningning Hong, Auteur ; Lei Song, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8253-8261
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Composite  material  Glass  fiber  Combustion  Thermal  degradation  Mechanical  properties
Résumé :	This work aims to develop glass-fiber reinforced poly(1,4-butylene terephthalate) (GRPBT) composites with enhanced mechanical, thermal stability, and flame retardancy properties using a novel compound, cerium hypophosphite (CHP). Mechanical performance studies showed that both the storage modulus and the tensile strength increased first and then decreased with increasing CHP content. For the GRPBT composite with 15 wt % of CHP, the storage modulus value at 30 °C was 3 times that of GRPBT. Thermogravimetric analysis (TGA) illustrated that low loading of CHP could improve the thermal stability of GRPBT composites. The volatilized esters measured by TGA coupled with FTIR (TGA-FTIR) in the decomposition of GRPBT with 20 wt % of CHP are decreased by about 69%. The combustion properties were evaluated by limiting oxygen index (LOI), Underwriters Laboratories 94 (UL 94), and cone calorimeter testing. For GRPBT containing 20 wt % of CHP, it achieved a V-0 classification with a high LOI (28.5%). Additionally, the peak heat release rate (PHRR) and total smoke production (TSP) were respectively reduced by around 76% and 45% as compared to the results obtained from GRPBT.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029660

[article] Studies on mechanical poperties, thermal degradation, and combustion behaviors of poly(1,4 - butylene terephthalate)/glass fiber/cerium hypophosphite composites [texte imprimé] / Wei Yang, Auteur ; Ningning Hong, Auteur ; Lei Song, Auteur . - 2012 . - pp. 8253-8261.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8253-8261

Mots-clés :	Composite  material  Glass  fiber  Combustion  Thermal  degradation  Mechanical  properties
Résumé :	This work aims to develop glass-fiber reinforced poly(1,4-butylene terephthalate) (GRPBT) composites with enhanced mechanical, thermal stability, and flame retardancy properties using a novel compound, cerium hypophosphite (CHP). Mechanical performance studies showed that both the storage modulus and the tensile strength increased first and then decreased with increasing CHP content. For the GRPBT composite with 15 wt % of CHP, the storage modulus value at 30 °C was 3 times that of GRPBT. Thermogravimetric analysis (TGA) illustrated that low loading of CHP could improve the thermal stability of GRPBT composites. The volatilized esters measured by TGA coupled with FTIR (TGA-FTIR) in the decomposition of GRPBT with 20 wt % of CHP are decreased by about 69%. The combustion properties were evaluated by limiting oxygen index (LOI), Underwriters Laboratories 94 (UL 94), and cone calorimeter testing. For GRPBT containing 20 wt % of CHP, it achieved a V-0 classification with a high LOI (28.5%). Additionally, the peak heat release rate (PHRR) and total smoke production (TSP) were respectively reduced by around 76% and 45% as compared to the results obtained from GRPBT.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029660

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8246–8252

Titre :	Microstructure Variations in Paper Coating : Direct Observations
Type de document :	texte imprimé
Auteurs :	Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8246–8252
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Microstructure  Paper  coating
Résumé :	Nonuniformities in the coating layer, such as porosity variations and binder distributions, are known to affect print uniformity and barrier properties. However, in the literature the results are rather scarce or sometimes conflicting. We acquired high-quality images of coated paper cross sections using field emission scanning electron microscopy in combination with a new argon-ion-beam milling technique to directly observe and analyze the coating microstructures in relation to underlying base sheet structures. The results showed that coating porosity varied with mass density of the underlying base sheet for the relatively bulky clay/GCC coating, whereas for the more compact clay coating, the effect was small. Areas with more fibers in the base sheet were more compressed by calendering, resulting in a decreased coating porosity. A unique binder enriched layer of less than 500 nm thickness was found at the coating surface as well as at the coating/base sheet interface.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202874z

[article] Microstructure Variations in Paper Coating : Direct Observations [texte imprimé] / Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur . - 2012 . - pp. 8246–8252.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8246–8252

Mots-clés :	Microstructure  Paper  coating
Résumé :	Nonuniformities in the coating layer, such as porosity variations and binder distributions, are known to affect print uniformity and barrier properties. However, in the literature the results are rather scarce or sometimes conflicting. We acquired high-quality images of coated paper cross sections using field emission scanning electron microscopy in combination with a new argon-ion-beam milling technique to directly observe and analyze the coating microstructures in relation to underlying base sheet structures. The results showed that coating porosity varied with mass density of the underlying base sheet for the relatively bulky clay/GCC coating, whereas for the more compact clay coating, the effect was small. Areas with more fibers in the base sheet were more compressed by calendering, resulting in a decreased coating porosity. A unique binder enriched layer of less than 500 nm thickness was found at the coating surface as well as at the coating/base sheet interface.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202874z

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8237–8245

Titre :	Gamma decomposition and powder formation of γ - U8Mo nuclear fuel alloys via a hydration – dehydration process
Type de document :	texte imprimé
Auteurs :	Fábio Branco Vaz de Oliveira, Auteur ; Adriano Michael Bernardin, Auteur ; Humberto Gracher Riella, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8237–8245
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Alloys  Nuclear  fuel
Résumé :	Gamma uranium–molybdenum alloys have been considered as the fuel phase in plate type fuel elements for material test reactor (MTR) reactors, mainly owing to their acceptable performance under irradiation and metallurgical processing. Regarding their usage as a dispersion phase in aluminum matrix, it is necessary to convert the as cast structure into powder, and one of the techniques considered for this purpose at IPEN/CNEN (Brazil) is by means of the HDH (hydration–dehydration) reactions. This paper shows that, under specific conditions of heating and cooling, hydration–dehydration is sometimes unnecessary, and γUMo fragmentation occurs in a nonreaction predominant mechanism, as shown by the curves of hydrogen absorption/desorption by the gamma uranium–molybdenum alloys as a function of time and temperature. Our focus was on the experimental results presented by the addition of 8% weight molybdenum. Subsequent to their production by induction melting, samples of the alloys were thermally treated under a constant flow of hydrogen for temperatures varying from 500 to 600 °C and for time of 2 to 4 h. The curves relating mass incorporation and time for the above-mentioned temperatures were obtained, and the results were related to the fragmentation. The main conclusion is that, even without a massive hydration–dehydration process, the samples could be fragmented under specific conditions of thermal treatment under the thermal shock phase of the experiments and that there is a strong correlation between absorption and the rate of gamma decomposition or the gamma phase stability of the alloy. In addition, a suggested value of 568.4 °C was obtained for the maximum rate of gamma decomposition, which can also be related to its eutectoid transformation temperature.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202708d

[article] Gamma decomposition and powder formation of γ - U8Mo nuclear fuel alloys via a hydration – dehydration process [texte imprimé] / Fábio Branco Vaz de Oliveira, Auteur ; Adriano Michael Bernardin, Auteur ; Humberto Gracher Riella, Auteur . - 2012 . - pp. 8237–8245.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8237–8245

Mots-clés :	Alloys  Nuclear  fuel
Résumé :	Gamma uranium–molybdenum alloys have been considered as the fuel phase in plate type fuel elements for material test reactor (MTR) reactors, mainly owing to their acceptable performance under irradiation and metallurgical processing. Regarding their usage as a dispersion phase in aluminum matrix, it is necessary to convert the as cast structure into powder, and one of the techniques considered for this purpose at IPEN/CNEN (Brazil) is by means of the HDH (hydration–dehydration) reactions. This paper shows that, under specific conditions of heating and cooling, hydration–dehydration is sometimes unnecessary, and γUMo fragmentation occurs in a nonreaction predominant mechanism, as shown by the curves of hydrogen absorption/desorption by the gamma uranium–molybdenum alloys as a function of time and temperature. Our focus was on the experimental results presented by the addition of 8% weight molybdenum. Subsequent to their production by induction melting, samples of the alloys were thermally treated under a constant flow of hydrogen for temperatures varying from 500 to 600 °C and for time of 2 to 4 h. The curves relating mass incorporation and time for the above-mentioned temperatures were obtained, and the results were related to the fragmentation. The main conclusion is that, even without a massive hydration–dehydration process, the samples could be fragmented under specific conditions of thermal treatment under the thermal shock phase of the experiments and that there is a strong correlation between absorption and the rate of gamma decomposition or the gamma phase stability of the alloy. In addition, a suggested value of 568.4 °C was obtained for the maximum rate of gamma decomposition, which can also be related to its eutectoid transformation temperature.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202708d

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8222-8236

Titre :	On the Consistent Modeling of Porous Catalyst Pellets : Mass and Molar Formulations
Type de document :	texte imprimé
Auteurs :	Jannike Solsvik, Auteur ; Stian Tangen, Auteur ; Hugo A. Jakobsen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8222-8236
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pellet  Catalyst  Modeling
Résumé :	Accurate modeling ofintrapartide heat and mass transport is a prerequisite for the design of many industrial processes and the interpretation of experiments. In the recent literature, deviations are noticed between simulation results of mole and mass formulated pellet model equations. For this reason, in this study, a comprehensive mathematical and numerical analysis has been performed. Several pellet model complexities are simulated to elucidate the effects of modeling assumptions on the behavior of the mass and mole formulated pellet model equations. Noted findings are as follows: (i) The simulation results show that the Wilke and Wilke-Bosanquet models with respect to the mass and mole average velocity definitions are not consistent. The Maxwell―Stefan and dusty gas closures are recommended; identical simulation results can be obtained with the mass and mole formulated pellet equations where the species mole and mass diffusion fluxes are defined relative to the respective average mixture velocities. (ii) Considering simplified models in which the convective terms are neglected, the species mole balance should be manipulated with the continuity equation to enforce the continuity balance of the mole number change. For the rigorous models retaining the convective terms, model manipulation by use of the continuity equation is still beneficial simplifying the model complexity and thus the implementation. Moreover, it is important to identify the velocity definitions used in the pellet equations and apply them consistently.
DEWEY :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029657

[article] On the Consistent Modeling of Porous Catalyst Pellets : Mass and Molar Formulations [texte imprimé] / Jannike Solsvik, Auteur ; Stian Tangen, Auteur ; Hugo A. Jakobsen, Auteur . - 2012 . - pp. 8222-8236.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8222-8236

Mots-clés :	Pellet  Catalyst  Modeling
Résumé :	Accurate modeling ofintrapartide heat and mass transport is a prerequisite for the design of many industrial processes and the interpretation of experiments. In the recent literature, deviations are noticed between simulation results of mole and mass formulated pellet model equations. For this reason, in this study, a comprehensive mathematical and numerical analysis has been performed. Several pellet model complexities are simulated to elucidate the effects of modeling assumptions on the behavior of the mass and mole formulated pellet model equations. Noted findings are as follows: (i) The simulation results show that the Wilke and Wilke-Bosanquet models with respect to the mass and mole average velocity definitions are not consistent. The Maxwell―Stefan and dusty gas closures are recommended; identical simulation results can be obtained with the mass and mole formulated pellet equations where the species mole and mass diffusion fluxes are defined relative to the respective average mixture velocities. (ii) Considering simplified models in which the convective terms are neglected, the species mole balance should be manipulated with the continuity equation to enforce the continuity balance of the mole number change. For the rigorous models retaining the convective terms, model manipulation by use of the continuity equation is still beneficial simplifying the model complexity and thus the implementation. Moreover, it is important to identify the velocity definitions used in the pellet equations and apply them consistently.
DEWEY :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029657

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8211-8221

Titre :	Optimization of integrated electro - bio process for bleaching effluent treatment
Type de document :	texte imprimé
Auteurs :	Soloman Poopana Antony, Auteur ; Balasubramanian Natesan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8211-8221
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bleaching  Optimization
Résumé :	The technical and economic feasibility of various electrochemical processes as pretreatment step for biological treatment for the management of kraft bagasse pulp bleach effluent has been studied, and the results are compared with that of the conventional chemical coagulation followed by biological treatment. A modeling methodology for integrating processes involving electrochemical and biological methods is proposed. Optimal combinations of operating variables giving a definite completion of pollutant removal are derived from the empirical models of each process. However, both the electrochemical steps as electrocoagulation and electro-oxidation were observed to perform technically better, and the former was noticeably more attractive based on the overall operating cost The cost of electrocoagulation-biological (EC-Bio) treatment giving 80% COD removal was determined to be US $0.166/m3. A 41% reduction in the treatment cost was achieved when the conventional chemical coagulation―biological (CC-Bio) methodology replaced by an EC-Bio system. The research revealed the feasibility of electrochemical steps as a primer in the reduction of organic load and improvement in the biodegradability of pulp-bleaching effluent.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029656

[article] Optimization of integrated electro - bio process for bleaching effluent treatment [texte imprimé] / Soloman Poopana Antony, Auteur ; Balasubramanian Natesan, Auteur . - 2012 . - pp. 8211-8221.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8211-8221

Mots-clés :	Bleaching  Optimization
Résumé :	The technical and economic feasibility of various electrochemical processes as pretreatment step for biological treatment for the management of kraft bagasse pulp bleach effluent has been studied, and the results are compared with that of the conventional chemical coagulation followed by biological treatment. A modeling methodology for integrating processes involving electrochemical and biological methods is proposed. Optimal combinations of operating variables giving a definite completion of pollutant removal are derived from the empirical models of each process. However, both the electrochemical steps as electrocoagulation and electro-oxidation were observed to perform technically better, and the former was noticeably more attractive based on the overall operating cost The cost of electrocoagulation-biological (EC-Bio) treatment giving 80% COD removal was determined to be US $0.166/m3. A 41% reduction in the treatment cost was achieved when the conventional chemical coagulation―biological (CC-Bio) methodology replaced by an EC-Bio system. The research revealed the feasibility of electrochemical steps as a primer in the reduction of organic load and improvement in the biodegradability of pulp-bleaching effluent.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029656

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8194-8210

Titre :	Electrochemical investigation of substituted pyranopyrazoles adsorption on mild steel in acid solution
Type de document :	texte imprimé
Auteurs :	Dileep Kumar Yadav, Auteur ; M. A. Quraishi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8194-8210
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mild  steel  Adsorption
Résumé :	Four substituted pyranopyrazole derivatives (PPZs) were synthesized and their effects on the electrochemical behavior of mild steel in 1 M HCl were investigated using gravimetric measurements, Tafel extrapolation method, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS). Tafel polarization measurements revealed that these compounds effectively suppressed both the anodic and cathodic processes of mild steel corrosion in add solution and acted as mixed-type inhibitors. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) examinations of electrode surface confirmed the existence of adherent layer of inhibitor on electrode surface. The UV―visible absorption spectrum of inhibitor solution containing mild steel indicated the formation of Fe―PPZ complex. Quantum chemical calculations have been used to evaluate the structural, electronic, and reactivity parameters of the selected pyranopyrazole derivatives in relation to their inhibition action.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029655

[article] Electrochemical investigation of substituted pyranopyrazoles adsorption on mild steel in acid solution [texte imprimé] / Dileep Kumar Yadav, Auteur ; M. A. Quraishi, Auteur . - 2012 . - pp. 8194-8210.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8194-8210

Mots-clés :	Mild  steel  Adsorption
Résumé :	Four substituted pyranopyrazole derivatives (PPZs) were synthesized and their effects on the electrochemical behavior of mild steel in 1 M HCl were investigated using gravimetric measurements, Tafel extrapolation method, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS). Tafel polarization measurements revealed that these compounds effectively suppressed both the anodic and cathodic processes of mild steel corrosion in add solution and acted as mixed-type inhibitors. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) examinations of electrode surface confirmed the existence of adherent layer of inhibitor on electrode surface. The UV―visible absorption spectrum of inhibitor solution containing mild steel indicated the formation of Fe―PPZ complex. Quantum chemical calculations have been used to evaluate the structural, electronic, and reactivity parameters of the selected pyranopyrazole derivatives in relation to their inhibition action.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029655

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012)

Titre :	Vaterite synthesis via gas – liquid route under controlled pH conditions
Type de document :	texte imprimé
Auteurs :	Ion Udrea, Auteur ; Constantin Capat, Auteur ; Elena A. Olaru, Auteur
Année de publication :	2012
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas  liquid  pH
Résumé :	The purpose of this work was to obtain precipitated calcium carbonate (PCC) particles in polymorphic form of vaterite via gas―liquid route in controlled pH conditions. The effect of CO2 concentration (12.5―100%), feed gas (CO2―air) flow rate, pH, and conductivity of solution upon the PCC particles properties was studied. On the basis of the experimental data, the main factors leading to vaterite formation as major product were established. It was found that the buffer solution has a decisive role in determining polymorphic phase of PCC while CO2 concentration and feed gas flow rate have no significant influence. It was demonstrated that spherical vaterite particles of high purity can be produced under controlled reaction conditions. Also, some considerations on the mechanism of carbonation process were formulated.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202221m

[article] Vaterite synthesis via gas – liquid route under controlled pH conditions [texte imprimé] / Ion Udrea, Auteur ; Constantin Capat, Auteur ; Elena A. Olaru, Auteur . - 2012.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012)

Mots-clés :	Gas  liquid  pH
Résumé :	The purpose of this work was to obtain precipitated calcium carbonate (PCC) particles in polymorphic form of vaterite via gas―liquid route in controlled pH conditions. The effect of CO2 concentration (12.5―100%), feed gas (CO2―air) flow rate, pH, and conductivity of solution upon the PCC particles properties was studied. On the basis of the experimental data, the main factors leading to vaterite formation as major product were established. It was found that the buffer solution has a decisive role in determining polymorphic phase of PCC while CO2 concentration and feed gas flow rate have no significant influence. It was demonstrated that spherical vaterite particles of high purity can be produced under controlled reaction conditions. Also, some considerations on the mechanism of carbonation process were formulated.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202221m

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8178-8184

Titre :	Preparation, characterization, and flame retardancy of novel rosin - based siloxane epoxy resins
Type de document :	texte imprimé
Auteurs :	Lianli Deng, Auteur ; Minmin Shen, Auteur ; Jing Yu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8178-8184
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Flame  Preparation
Résumé :	A series of novel rosin-based siloxane epoxy resins (AESE copolymers) were prepared by the reaction of ethylene glycol diglycidyl ether modified acrylpimaric acid (AP-EGDE) with poly(methylphenylsiloxane). The chemical structures of the produced epoxy resins were determined by FTIR, 1H-NMR, 13C-NMR, and epoxy equivalent weight (EEW) test. After modification, the tensile strengths of AESE (20-40) are slightly lower than that of AP-EGDE; however their breaking elongations are higher than that of AP-EGDE remarkably. TGA results reveal that the thermal stability of AESE serials is better than that of AP-EGDE due to the formation of a protective residue. The char residue of AESE increases at 700 °C with its silicon content increases. Nevertheless, there is a peak LOI value for AESE when its silicon content is 30%. Moreover, the chemical structures of char at the end of the LOI test were analyzed by FTIR The results confirmed the formation of the protective residue.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029653

[article] Preparation, characterization, and flame retardancy of novel rosin - based siloxane epoxy resins [texte imprimé] / Lianli Deng, Auteur ; Minmin Shen, Auteur ; Jing Yu, Auteur . - 2012 . - pp. 8178-8184.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8178-8184

Mots-clés :	Flame  Preparation
Résumé :	A series of novel rosin-based siloxane epoxy resins (AESE copolymers) were prepared by the reaction of ethylene glycol diglycidyl ether modified acrylpimaric acid (AP-EGDE) with poly(methylphenylsiloxane). The chemical structures of the produced epoxy resins were determined by FTIR, 1H-NMR, 13C-NMR, and epoxy equivalent weight (EEW) test. After modification, the tensile strengths of AESE (20-40) are slightly lower than that of AP-EGDE; however their breaking elongations are higher than that of AP-EGDE remarkably. TGA results reveal that the thermal stability of AESE serials is better than that of AP-EGDE due to the formation of a protective residue. The char residue of AESE increases at 700 °C with its silicon content increases. Nevertheless, there is a peak LOI value for AESE when its silicon content is 30%. Moreover, the chemical structures of char at the end of the LOI test were analyzed by FTIR The results confirmed the formation of the protective residue.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26029653

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8149–8177

Titre :	State - of - the - art of CO2 capture with ionic liquids
Type de document :	texte imprimé
Auteurs :	Mahinder Ramdin, Auteur ; Theo W. de Loos, Auteur ; Thijs J.H. Vlugt, Auteur
Année de publication :	2012
Article en page(s) :	pp. 8149–8177
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic  liquids
Résumé :	Economical and environmental aspects are the main motivation for research on energy efficient processes and the search for environment friendly materials for CO2 capture. Currently, CO2 capture is dominated by amine-based (e.g., monoethanolamine) technologies, which are very energy intensive and less attractive from an environmental point of view due to emissions of the used volatile solvent components. Ionic liquids have been proposed as a promising alternative to the conventional volatile solvents, because of their low volatility and other interesting properties. This remarkable interest has led to a rapid growth of literature on this specific subject. The aim of the present review paper is to provide a detailed overview of the achievements and difficulties that has been encountered in finding a suitable ionic liquid for CO2 capture from flue-gas streams. A major part of this review includes an overview of the experimental data of CO2 solubility, selectivity, and diffusivity in different ionic liquids. The effect of anions, cations, and functional groups on the CO2 solubility, biodegradability, and toxicity of the ionic liquids are highlighted. Recent developments on task-specific ionic liquids and supported ionic liquid membranes are also discussed. Scarcely available results of molecular simulations, which is a valuable tool in designing and evaluating ionic liquids, are also reviewed. The trends highlighted here can be used by solvent designers to navigate through the massive amount of theoretically possible ILs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3003705

[article] State - of - the - art of CO2 capture with ionic liquids [texte imprimé] / Mahinder Ramdin, Auteur ; Theo W. de Loos, Auteur ; Thijs J.H. Vlugt, Auteur . - 2012 . - pp. 8149–8177.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8149–8177

Mots-clés :	Ionic  liquids
Résumé :	Economical and environmental aspects are the main motivation for research on energy efficient processes and the search for environment friendly materials for CO2 capture. Currently, CO2 capture is dominated by amine-based (e.g., monoethanolamine) technologies, which are very energy intensive and less attractive from an environmental point of view due to emissions of the used volatile solvent components. Ionic liquids have been proposed as a promising alternative to the conventional volatile solvents, because of their low volatility and other interesting properties. This remarkable interest has led to a rapid growth of literature on this specific subject. The aim of the present review paper is to provide a detailed overview of the achievements and difficulties that has been encountered in finding a suitable ionic liquid for CO2 capture from flue-gas streams. A major part of this review includes an overview of the experimental data of CO2 solubility, selectivity, and diffusivity in different ionic liquids. The effect of anions, cations, and functional groups on the CO2 solubility, biodegradability, and toxicity of the ionic liquids are highlighted. Recent developments on task-specific ionic liquids and supported ionic liquid membranes are also discussed. Scarcely available results of molecular simulations, which is a valuable tool in designing and evaluating ionic liquids, are also reviewed. The trends highlighted here can be used by solvent designers to navigate through the massive amount of theoretically possible ILs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3003705