利用改性的纤维介质作为酵母固定化载体,在1 m3发酵罐中,考察温度、初始pH及循环量对固定化酵母发酵的影响.结果显示:在温度34℃、初始pH 4.4和循环量为2.0 m3/h的条件下,淀粉利用率可达86.7％,生产1 t乙醇的粮耗达2.89 t.在最优的工艺条件下,进行了30 t罐模拟放大试验,分析不同淀粉质原料条件下的淀粉转化率和粮耗.结果表明:固定化酵母发酵淀粉转化率和产1 t乙醇粮耗分别为85.8％和2.93 t;在高浓度糖条件下,酒精度可达15.3％(体积分数),实现高浓酒精发酵;利用玉米原料,同样可以达到长期稳定发酵的效果,满足工业原料多元化的生产.从本次实验的小试和中试结果来看,利用基于微生物集群效应的固定化酵母发酵体系具有较强的工业应用价值.%Modified fibrous materials was used as yeast immobilization carrier for ethanol fermentation,and effects of temperature, initial pH and circulation on the immobilized yeast fermentation in a 1-m3 fermentation tank were analyzed. The starch utilization rate increased to 86. 7％ and cereal consumption reduced to 2. 89 t for 1 t ethanol production at temperature of 34 ℃,initial pH of 4. 4,and circulating volume of 2. 0 m3/h. We further carried out the scaling-up experiment of 30 tons to simulate industrial production under the optimal process condition, which showed that starch conversion rate and cereal consumption were 85. 8％ and 2. 93 t per ton ethanol, respectively. Under the condition of high concentration of sugar, alcohol degrees reached 15. 3％( V/V ) , high concentration alcohol fermentation was obtained; corn fermentation also achieved long-term, stable fermentation, and meets the need of industrial fermentation. The results of laboratory scale experiment and pilot scale experiments show the surface immobilized yeast cell fermentation has potential for industrial application.
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