乙醇连续发酵与膜超滤耦合过程研究

RESEARCH OF PROCESS OF ETHANOL CONTINUOUS FERMENTATION COUPLING WITH SEPARATION BY CA-Ti UF TUBULAR MEMBRANE

采用ＣＡ－Ｔｉ复合管式膜组件与发酵釜耦合操作，用啤酒酵母从葡萄糖连续发酵乙醇是一个从不稳态到稳态的过程。稳态的最佳操作参数为：初始葡萄糖浓度为１４０ｇ／Ｌ，稀释率为０．３ｈ－１，轴出比为０．６３８，相应的细胞浓度为２×１０９ｃｅｌｌｓ／ｍｌ，葡萄糖利用率为９２％，生产率为２２９／Ｌ·ｈ。ＣＡ－Ｔｉ复合管式膜经松弛法处理后，可使膜的渗透通量得到恢复。当细胞浓度增加到一定程度时，乙醇生产率和酵母比生长速率的增长减缓。

The study of continuous fermentation of ethanol coupling with separation by UF membrane is one of the key points in the biochemical engineering field at present.This coupling course says that it is a course from unsteadiness to steadiness.The main parameters to reach steadiness are bleed ratio,which can be defined symptomatically with the dilution ratio,the growth rate of cells and the function of the membrane.The finest operations are:S0=140g/L,D=0.3h-1,B=0.638.The concentration of the cell is 2×109 cells/ml,the utilization ratio of glucose is more than 90%, and tie productivity is 22g/(L·h).The method is to efficiently resume the flux which we name the relaxation of CA-Ti UF tubular membrane module.The ethanol productivity and yeast growth rate decrease as the cell concertration increase beyond a certain level.The cell mass in the reactor is maintained by a proper manipulation of dilution rate and bleed ratio depending on the growth rate.