A novel surface deposition modified ceramic m embrane was developed to decrease the membrane pore size.Accordingly r-alumina supported membranes modified by calcium carbonate were prepared.Pore size distribution deter...A novel surface deposition modified ceramic m embrane was developed to decrease the membrane pore size.Accordingly r-alumina supported membranes modified by calcium carbonate were prepared.Pore size distribution determination and SEM photographs of membranes mdicated that this modi fied membrane can reduce pore size effectively and improve the membrane separation property obviously.Comparisons of vapor permeation separation of ethanol/water mixtures between alumina membranes unmodified and those modified by CaCO3 also supported the improvement.展开更多
The separation characteristics of the PVA-CS (polyvinyl alcohol-chitosan) blended composite membrane for dehydration of ethanol-water mixture are examined. The relationships of flux and separation factor with the feed...The separation characteristics of the PVA-CS (polyvinyl alcohol-chitosan) blended composite membrane for dehydration of ethanol-water mixture are examined. The relationships of flux and separation factor with the feed concentration and operation temperature are established. Using this correlated equation, the continuous-flow pervaporation process about 500 kilolitres/year dehydrated ethanol is designed. The numbers of stage and reheater are calculated by stage-by-stage method for two kinds of cascades: one with equal membrane area and the other with 10℃ of temperature decrement per section. The results show that when the numbers of stage and reheater are the same, the cascade with 10℃ of temperature decrement has more advantages than that with equal membrane area. The influences of feed concentration and flow rate on the numbers of stage and reheater in the cascades are discussed.展开更多
Four empirical models are tested for fitting the T-y-x equilibrium data of ethanol-water mixture by minimizing the Root Mean Square （RMS） between equilibrium data and theoretical points. The total pressure of the co...Four empirical models are tested for fitting the T-y-x equilibrium data of ethanol-water mixture by minimizing the Root Mean Square （RMS） between equilibrium data and theoretical points. The total pressure of the correspondent data is 101.3 kPa. All models parameters are also identified. The study suggests that NRTL model fits the equilibrium data best with RMS = 0.4 %.展开更多
文摘A novel surface deposition modified ceramic m embrane was developed to decrease the membrane pore size.Accordingly r-alumina supported membranes modified by calcium carbonate were prepared.Pore size distribution determination and SEM photographs of membranes mdicated that this modi fied membrane can reduce pore size effectively and improve the membrane separation property obviously.Comparisons of vapor permeation separation of ethanol/water mixtures between alumina membranes unmodified and those modified by CaCO3 also supported the improvement.
基金Supported by the National Natural Science Foundation of China(No.29836160) and Commission of Science & Technology of Zhejiang Province(No.924010,No.85-12-02-05).
文摘The separation characteristics of the PVA-CS (polyvinyl alcohol-chitosan) blended composite membrane for dehydration of ethanol-water mixture are examined. The relationships of flux and separation factor with the feed concentration and operation temperature are established. Using this correlated equation, the continuous-flow pervaporation process about 500 kilolitres/year dehydrated ethanol is designed. The numbers of stage and reheater are calculated by stage-by-stage method for two kinds of cascades: one with equal membrane area and the other with 10℃ of temperature decrement per section. The results show that when the numbers of stage and reheater are the same, the cascade with 10℃ of temperature decrement has more advantages than that with equal membrane area. The influences of feed concentration and flow rate on the numbers of stage and reheater in the cascades are discussed.
文摘Four empirical models are tested for fitting the T-y-x equilibrium data of ethanol-water mixture by minimizing the Root Mean Square （RMS） between equilibrium data and theoretical points. The total pressure of the correspondent data is 101.3 kPa. All models parameters are also identified. The study suggests that NRTL model fits the equilibrium data best with RMS = 0.4 %.
