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Bubbling reactor technology for rapid synthesis of uniform, small MFI-type zeolite crystals / Wei Liu in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7241-7250 Titre : Bubbling reactor technology for rapid synthesis of uniform, small MFI-type zeolite crystals Type de document : texte imprimé Auteurs : Wei Liu, Auteur ; Yuxiang Rao, Auteur ; Haiying Wan, Auteur Année de publication : 2011 Article en page(s) : pp. 7241-7250 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite  Reactor  Bubbling Résumé : MFI-type zeolite is an important family of materials used in today's industries as catalysts and adsorbents. Preparation of this type of zeolite material as uniform and pure crystals with sizes from tens to hundreds of nanometers are not only desired for current catalytic and adsorption processes for enhanced reaction kinetics and/or selectivity, but also much needed for some new applications, such as CO2 capture adsorbents and composite materials. However, it has been a major challenge in the field of zeolite synthesis to prepare small crystals of MFI-type zeolite over a range of Si/Al ratios with very high throughput. In this work, a gas-bubbling flow reactor was used to conduct hydrothermal growth of the zeolite crystals with controllable Si/Al ratios and crystal sizes. Distinctive, uniform ZSM-5 crystals were successfully synthesized within 2 h ofreaction time, which is exceptionally short compared to the conventional synthesis process. The crystals were small enough to form a stable milk-like suspension in water. The Si/Al ratio was controlled by adjusting the growth solution composition and reaction conditions over a range from about 9 to infinity. Characterization by SEM/EDS, XRD, TEM, N2 adsorption/desorption, and NMR spectroscopy confirmed the ZSM-5 crystal structures and revealed the presence of mesoporosity in the resulting crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239038 [article] Bubbling reactor technology for rapid synthesis of uniform, small MFI-type zeolite crystals [texte imprimé] / Wei Liu, Auteur ; Yuxiang Rao, Auteur ; Haiying Wan, Auteur . - 2011 . - pp. 7241-7250. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7241-7250 Mots-clés : Zeolite  Reactor  Bubbling Résumé : MFI-type zeolite is an important family of materials used in today's industries as catalysts and adsorbents. Preparation of this type of zeolite material as uniform and pure crystals with sizes from tens to hundreds of nanometers are not only desired for current catalytic and adsorption processes for enhanced reaction kinetics and/or selectivity, but also much needed for some new applications, such as CO2 capture adsorbents and composite materials. However, it has been a major challenge in the field of zeolite synthesis to prepare small crystals of MFI-type zeolite over a range of Si/Al ratios with very high throughput. In this work, a gas-bubbling flow reactor was used to conduct hydrothermal growth of the zeolite crystals with controllable Si/Al ratios and crystal sizes. Distinctive, uniform ZSM-5 crystals were successfully synthesized within 2 h ofreaction time, which is exceptionally short compared to the conventional synthesis process. The crystals were small enough to form a stable milk-like suspension in water. The Si/Al ratio was controlled by adjusting the growth solution composition and reaction conditions over a range from about 9 to infinity. Characterization by SEM/EDS, XRD, TEM, N2 adsorption/desorption, and NMR spectroscopy confirmed the ZSM-5 crystal structures and revealed the presence of mesoporosity in the resulting crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239038

Effect of hemicellulose pre - extraction on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp / Wei Liu in Industrial & engineering chemistry research, Vol. 51 N° 34 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11122-11127 Titre : Effect of hemicellulose pre - extraction on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp Type de document : texte imprimé Auteurs : Wei Liu, Auteur ; Qingxi Hou, Auteur ; Changbin Mao, Auteur Année de publication : 2012 Article en page(s) : pp. 11122-11127 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemithermomechanical  pulp Résumé : Pre-extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other byproducts will provide additional revenue to the traditional pulp and paper industry. The effect of hemicelluloses pre-extraction with dilute sulfuric acid on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp (CTMP) was investigated. The acid pre-extraction significantly reduced refining energy consumption to a given freeness. However, at the same freeness, the acid pre-extraction resulted in the reduction of bulk, tensile index, and zero-span breaking length, fewer long fibers and more fines, but an increase of the Scott bond strength. Alkaline peroxide bleaching can compensate the strength loss, but the bleachability of pulps with acid pre-extraction was lower than that of the control. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299437 [article] Effect of hemicellulose pre - extraction on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp [texte imprimé] / Wei Liu, Auteur ; Qingxi Hou, Auteur ; Changbin Mao, Auteur . - 2012 . - pp. 11122-11127. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11122-11127 Mots-clés : Chemithermomechanical  pulp Résumé : Pre-extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other byproducts will provide additional revenue to the traditional pulp and paper industry. The effect of hemicelluloses pre-extraction with dilute sulfuric acid on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp (CTMP) was investigated. The acid pre-extraction significantly reduced refining energy consumption to a given freeness. However, at the same freeness, the acid pre-extraction resulted in the reduction of bulk, tensile index, and zero-span breaking length, fewer long fibers and more fines, but an increase of the Scott bond strength. Alkaline peroxide bleaching can compensate the strength loss, but the bleachability of pulps with acid pre-extraction was lower than that of the control. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299437

Externally heat-integrated double distillation column (EHIDDiC) / Kejin Huang in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010)

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1333–1350 Titre : Externally heat-integrated double distillation column (EHIDDiC) : basic concept and general characteristics Type de document : texte imprimé Auteurs : Kejin Huang, Auteur ; Wei Liu, Auteur ; Jiangpeng Ma, Auteur Année de publication : 2010 Article en page(s) : pp. 1333–1350 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Externally--Heat-Integrated--Double  Distillation--Column  (EHIDDi--Basic  Concept--General  Characteristics Résumé : In terms of the thermodynamic characteristics of simple distillation columns, a novel schematic of an externally heat-integrated double distillation column (EHIDDiC) is proposed and studied in this work. It consists of high-pressure and low-pressure distillation columns, with external heat integration between the whole rectifying section of the former and the whole stripping section of the latter. In comparison with conventional distillation systems (i.e., direct and indirect separation sequences), the EHIDDiC was found to require relatively small capital investment and low operating costs. It can even outperform conventional distillation systems with the condenser/reboiler type of heat integration under some favorable operating conditions. In terms of the separation of a ternary ideal mixture containing hypothetical components A, B, and C, the EHIDDiC was evaluated through intensive comparisons with its conventional counterparts. Sensitivity analysis was also conducted with respect to some relevant physical properties and design parameters, including the relative volatilities, feed composition, external heat-transfer area per stage, product specifications, and utility costs. It was confirmed that the EHIDDiC can be advantageous over conventional distillation systems with and without condenser/reboiler-type heat integration, and the results obtained reflect the salient characteristics of the EHIDDiC. ISSN : 0888-5885 [article] Externally heat-integrated double distillation column (EHIDDiC) : basic concept and general characteristics [texte imprimé] / Kejin Huang, Auteur ; Wei Liu, Auteur ; Jiangpeng Ma, Auteur . - 2010 . - pp. 1333–1350. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1333–1350 Mots-clés : Externally--Heat-Integrated--Double  Distillation--Column  (EHIDDi--Basic  Concept--General  Characteristics Résumé : In terms of the thermodynamic characteristics of simple distillation columns, a novel schematic of an externally heat-integrated double distillation column (EHIDDiC) is proposed and studied in this work. It consists of high-pressure and low-pressure distillation columns, with external heat integration between the whole rectifying section of the former and the whole stripping section of the latter. In comparison with conventional distillation systems (i.e., direct and indirect separation sequences), the EHIDDiC was found to require relatively small capital investment and low operating costs. It can even outperform conventional distillation systems with the condenser/reboiler type of heat integration under some favorable operating conditions. In terms of the separation of a ternary ideal mixture containing hypothetical components A, B, and C, the EHIDDiC was evaluated through intensive comparisons with its conventional counterparts. Sensitivity analysis was also conducted with respect to some relevant physical properties and design parameters, including the relative volatilities, feed composition, external heat-transfer area per stage, product specifications, and utility costs. It was confirmed that the EHIDDiC can be advantageous over conventional distillation systems with and without condenser/reboiler-type heat integration, and the results obtained reflect the salient characteristics of the EHIDDiC. ISSN : 0888-5885

Preparation of robust, thin zeolite membrane sheet for molecular separation / Wei Liu in Industrial & engineering chemistry research, Vol. 50 N° 20 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11677-11689 Titre : Preparation of robust, thin zeolite membrane sheet for molecular separation Type de document : texte imprimé Auteurs : Wei Liu, Auteur ; Jian Zhang, Auteur ; Nathan Canfield, Auteur Année de publication : 2011 Article en page(s) : pp. 11677-11689 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite  Inorganic  membrane  Preparation Résumé : This paper reports a feasibility study on the preparation of zeolite membrane films on a thin, porous metal support sheet (50 μm thick). Zeolite sodium A (NaA) and silicalite zeolite frameworks are chosen to represent syntheses of respective hydrophilic-type and hydrophobic-type zeolite membranes on this new support. It is found that a dense, continuous intergrown zeolite crystal layer at a thickness less than 3 μm can be directly deposited on such a support by using direct and secondary growth techniques. The resulting membrane shows excellent adhesion on the metal sheet. Molecular-sieving functions of the prepared membranes are characterized with ethanol/water separation, CO2 separation, and air dehumidification. The results show great potential to make flexible metal-foil-like zeolite membranes for a range of energy conversion and environmental applications. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612393 [article] Preparation of robust, thin zeolite membrane sheet for molecular separation [texte imprimé] / Wei Liu, Auteur ; Jian Zhang, Auteur ; Nathan Canfield, Auteur . - 2011 . - pp. 11677-11689. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11677-11689 Mots-clés : Zeolite  Inorganic  membrane  Preparation Résumé : This paper reports a feasibility study on the preparation of zeolite membrane films on a thin, porous metal support sheet (50 μm thick). Zeolite sodium A (NaA) and silicalite zeolite frameworks are chosen to represent syntheses of respective hydrophilic-type and hydrophobic-type zeolite membranes on this new support. It is found that a dense, continuous intergrown zeolite crystal layer at a thickness less than 3 μm can be directly deposited on such a support by using direct and secondary growth techniques. The resulting membrane shows excellent adhesion on the metal sheet. Molecular-sieving functions of the prepared membranes are characterized with ethanol/water separation, CO2 separation, and air dehumidification. The results show great potential to make flexible metal-foil-like zeolite membranes for a range of energy conversion and environmental applications. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612393

Reactive deposition of palladium nanoparticles onto zeolite membranes in supercritical CO2 / Xiufeng Liu in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8826–8831 Titre : Reactive deposition of palladium nanoparticles onto zeolite membranes in supercritical CO2 Type de document : texte imprimé Auteurs : Xiufeng Liu, Auteur ; Wei Liu, Auteur ; Jian Li, Auteur Année de publication : 2010 Article en page(s) : pp. 8826–8831 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanoparticles  Zeolite  membranes Résumé : Pd/Si-MFI membranes are fabricated by depositing palladium nanoparticles onto Si-MFI membranes via opposing reactants chemical fluid deposition in supercritical carbon dioxide. Palladium hexafluoroacetylacetonate [Pd(hfac)2] and ethanol are used as the Pd precursor and the reducing agent, respectively, in the deposition process. The resulting Pd/Si-MFI membrane is characterized using SEM, XRD, EPMA, TEM, and EDX techniques. It is demonstrated that a continuous layer of Pd particles with size of 10 nm is covered on the matrix surface while 30-nm Pd particles are plugged into the defects within the matrix. The H2/N2 permselectivity has been significantly increased due to the deposition of Pd nanoparticles in the Si-MFI membrane, which could keep stable below the critical temperature. This bifunctional membrane and similar membranes possess the application potential to achieve various one-step syntheses. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100655m [article] Reactive deposition of palladium nanoparticles onto zeolite membranes in supercritical CO2 [texte imprimé] / Xiufeng Liu, Auteur ; Wei Liu, Auteur ; Jian Li, Auteur . - 2010 . - pp. 8826–8831. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8826–8831 Mots-clés : Nanoparticles  Zeolite  membranes Résumé : Pd/Si-MFI membranes are fabricated by depositing palladium nanoparticles onto Si-MFI membranes via opposing reactants chemical fluid deposition in supercritical carbon dioxide. Palladium hexafluoroacetylacetonate [Pd(hfac)2] and ethanol are used as the Pd precursor and the reducing agent, respectively, in the deposition process. The resulting Pd/Si-MFI membrane is characterized using SEM, XRD, EPMA, TEM, and EDX techniques. It is demonstrated that a continuous layer of Pd particles with size of 10 nm is covered on the matrix surface while 30-nm Pd particles are plugged into the defects within the matrix. The H2/N2 permselectivity has been significantly increased due to the deposition of Pd nanoparticles in the Si-MFI membrane, which could keep stable below the critical temperature. This bifunctional membrane and similar membranes possess the application potential to achieve various one-step syntheses. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100655m

Thermodynamics studies on the solubility of inorganic salt in organic solvents / Bingwen Long in Industrial & engineering chemistry research, Vol. 51 N° 28 (Juillet 2012) 

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