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Sourav Mondal Raka Mukherjee Somak Chatterjee Sirshendu De 《American Institute of Chemical Engineers》2014,60(6):2354-2364
Adsorption has been found to be significant in ultrafiltration by mixed matrix membrane. Removal of very low molecular weight solutes compared to the molecular weight cut off of the membrane is facilitated by adsorption. The modeling of the adsorption coupled with concentration polarization is presented based on the mathematical approach developed by Gekas et al. (Gekas et al. Chem Eng Sci. 1993;48:2753–2765), from the first principles. However, extensive modifications were included in theoretical development including those suggested by Ruiz‐Bevia et al. (Ruiz‐Bevia et al. Chem Eng Sci. 1997;52:2343–2352). The developed model captured the rejection dynamics with the help of retention factor. The model equations were solved under the framework of boundary layer analysis, using the integral approach. Effects of the adsorption isotherm and the different parameters affecting the system performance were also investigated. Further, experimental validation of the model results with two different mixed matrix ultrafiltration studies was also elucidated. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2354–2364, 2014 相似文献
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In current or next-generation reuse systems, the development of new classes of antifouling membranes is needed before viable membrane-based approaches for wastewater reclamation can be achieved. In this study, ZrO2/PES hybrid ultrafiltration membranes with uniform ZrO2 nanoparticles were prepared by combining an ion-exchange process with a traditional immersion precipitation process. Hydrous ZrO2 sol was synthesized by addition of anion-exchange resin in N,N-dimethylformamide solvent containing zirconyl chloride. Homogeneous ZrO2/PES casting solution was then obtained by dissolving PES polymer in the ZrO2 sol. The existence and dispersion states of ZrO2 nanoparticles in the resultant membrane matrix were examined by X-ray photoelectron spectrometer, thermogravimetric analysis, scanning electron microscope and transmission electron microscope. The results indicate that the ZrO2 nanoparticles were well dispersed throughout the PES matrix and the diameter of the formed nanoparticles was about 5–10 nm. The hydrophilicity of the membranes was determined by measuring the contact angles. The antifouling property was determined by antifouling experiments and atomic force microscopy. The results confirm that the existence of ZrO2 nanoparticles improves the hydrophilicity and reduces protein adsorption of membranes. 相似文献
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A new air-gap membrane distillation (AGMD) module for desalination with internal latent-heat-recovery which consisted of parallel hollow fiber membranes and heat exchange hollow fibers was successfully developed. The influences of feed flow rate, feed temperature and feed initial concentration on AGMD process were investigated. The vapor pressure polarization coefficient (η) was introduced to measure the reduction in the effective driving force for mass transfer with regard to the driving force imposed. Among all AGMD experiments, the maximum water vapor permeate flux (JD) of 5.30 kg/m2 h and the gained output ratio (GOR) of 5.70 were obtained. A theoretical model based on the mass and energy balances of the hot feed side was established to calculate the temperature and the local water vapor permeate flux distributions along the hollow fiber membrane, which showed that the temperature drop and local water vapor permeate flux drop were much larger at the upper part than those at the lower part of the membrane module in the hot feed side. 相似文献
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Partial oxidation of methane in hollow‐fiber membrane reactors based on alkaline‐earth metal‐free CO2‐tolerant oxide 下载免费PDF全文
Yanying Wei Qing Liao Zhong Li Haihui Wang Armin Feldhoff Juergen Caro 《American Institute of Chemical Engineers》2014,60(10):3587-3595
The U‐shaped alkaline‐earth metal‐free CO2‐stable oxide hollow‐fiber membranes based on (Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+δ (PLNCG) are prepared by a phase‐inversion spinning process and applied successfully in the partial oxidation of methane (POM) to syngas. The effects of temperature, CH4 concentration and flow rate of the feed air on CH4 conversion, CO selectivity, H2/CO ratio, and oxygen permeation flux through the PLNCG hollow‐fiber membrane are investigated in detail. The oxygen permeation flux arrives at approximately 10.5 mL/min cm2 and the CO selectivity is higher than 99.5% with a CH4 conversion of 97.0% and a H2/CO ratio of 1.8 during 140 h steady operation. The spent hollow‐fiber membrane still maintains a dense microstructure and the Ruddlesden‐Popper K2NiF4‐type structure, which indicates that the U‐shaped alkaline‐earth metal‐free CO2‐tolerant PLNCG hollow‐fiber membrane reactor can be steadily operated for POM to syngas with good performance. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3587–3595, 2014 相似文献