【摘要】 将硅橡胶膜(PDMS)渗透汽化分离与酵母细胞固定床耦合构成连续发酵系统,进行了乙醇发酵实验。发酵操作连续进行了378.5h,发酵液内的乙醇质量浓度最高达到了70g/L,启动PDMS膜分离后,降低并维持在50g/L左右;实验得到固定化颗粒和发酵液内的最高细胞浓度分别为1.76×1010个/g和9.8×108个/mL;乙醇体积产率3.67g/L·h,为游离连续发酵的2.1倍,葡萄糖消耗速率11.05g/L·h,为游离连续发酵的2.5倍;膜总通量400～690g/m·2h,乙醇通量为80～190g/m·2h,分离因子2.5～7.2,下游产品的平均质量浓度191.57g/L。更多还原

【Abstract】 A continuous ethanol fermentation system by immobilized yeast cells associated with prevaporation by PDMS membrane was constructed. A continuous fermentation experiment was conducted and 378.5 h continuous fermentation was achieved. The mass concentration of ethanol in the broth reached up to 70 g/L, and dropped to about 50 g/L after PDMS membrane separation started. The cell density in immobilized particles and in the broth were up to 1.76×1010 cells/g and 9.8×108 cells/mL respectively. The ethanol productivity rate was 3.67 g/ (L·h) and the glucose utilization rate was 11.05 g/(L·h), 2.1 times and 2.5 times of continuous ethanol fermentation by free cells respectively. The total flux and the ethanol flux of the membrane were 400 g/(m2·h)～690 g/(m2·h) and 80 g/(m2·h)～190 g/(m2·h), while the selectivity varied between 2.5 and 7.2. The average mass concentration of ethanol of the permeate was 191.57 g/L.更多还原