توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱The Effect of settled bed height and bed expansion on hydrodynamic behavior of expanded bed adsorption for protein purification
نویسنده(ها): ، ،
اطلاعات انتشار: دهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۲
Fluidized\Expanded bed adsorption (EBA) has received increasing attentions as an effective technique for the purification of proteins directly from cell homogenates or fermentation broths in downstream processing .To widely extend the EBA technology in biological industries, better understanding of the expanded–bed behavior is necessary to maximize its efficient applications .In this study streamline–DEAE adsorbent was loaded into 1.6cm and 1cm column and comparison of liquid phase mixing with different settled bed height(SBH) (SBH=5,6,7,8,9,10,11,12cm) and different bed expansion (30%,80%, 130%,180%),respectively ,for obtaining the optimal SBH and bed expansion has been carried out. Hydrodynamic characteristics (based on RTD experiments )of 9 cm for SBH and 130% for bed expansion demonstrated a minimal mixing which is desirable for Macromolecular and Nanoparticle purification. The generic effect of settled bed height and bed expansion and subsequently bioseperation performance in such integrated processes is fully discussed.<\div>

۲A generic model for prediction of separation performance of olefin\paraffin mixtures by glassy polymer membranes
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۱۲
In this study, separation behavior of olefin\paraffin mixtures through glassy polymer membranes was modeled by three different approaches. The so–called dual transport model, the basic adsorption–diffusion theory and the general Maxwell–Stefan formulation. A critical examination of dual transport mode revealed that this model fails clearly to predict even the proper trend for selectivities. The results obtained from the examination the basic adsorption–diffusion theory show a good agreement with the experimental data. However, in this approach mixed permeability data were used for estimation of diffusion coefficients, which fades out the advantages of prediction of multicomponent separation performance from pure component data. Finally, It was demonstrated by the modeling results that the generic model developed based on Maxwell–Stefan theory is capable to describe effectively the separation behavior of olefin\paraffin mixtures using only pure component sorption and permeation data. The success of this model in prediction of separation performance can be attributed to the proper consideration of thermodynamic and kinetic interactions in multicomponent transport across the membrane.<\div>

۳Solubility and diffusional coupling effects on mixed gas transport through glassy polymeric membranes.
نویسنده(ها): ، ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۸
The presence of a second component in a two component penetrant system has been shown to affect the transport and separation properties of a glassy polymer. However, such coupling effects appear to be absent in the rubbery polymer. The estimation of gas solubility and diffusion
coefficients for mixed gas under individual gases permeation conditions assists us in better understanding of the true transport phenomena involved. In this study, the equilibrium sorption of mixtures in various polymers was modeled using the experimental data available in the
literature. The non–ideal effects arising from the presence of other gas is the objective of this research and is presented in this work.<\div>

۴Modeling of an isothermal and non–isothermal tubular membrane reactor for conversion of synthesis gas to methanol
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۱۱
Production yield of methanol from syngas in a traditional fixed bed reactor at the temperature and pressure required for the optimum catalyst activity is restricted by the thermodynamic equilibrium. By selective removal of the reaction products from the catalytic reactor bed using a membrane, it is possible to improve the reaction yield. In order to investigate the effect of the presence of the membrane as a selective separation barrier on the methanol yield, the performance of a tubular membrane reactor was simulated by a mathematical model. The model was developed using differential material, energy and momentum balances and the set of describing equations were solved numerically to give the composition, temperature and pressure profile along the reactor. The model validated using the experimental data available in the literature for two kinds of zeolite membranes (methanol selective and water selective). The modeling results show that in either cases methanol yield is improved by using the membrane reactor in comparison to the traditional reactor. In addition, the yield improvement is more considerable using a zeolite membrane with a higher permeability of methanol over water.<\div>
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