利用SSF制取纤维乙醇的工艺研究

Study on production of ethanol by simultaneous saccharification and fermentation from cellulose

利用同步糖化发酵(SSF)技术,以汽爆玉米秸秆为主要原料,对纤维乙醇的发酵工艺进行研究。玉米秸秆经蒸汽爆破预处理后,酶解得率增大到85.0%。进一步利用Box-Behnken实验设计方法,选取酶用量、发酵温度和发酵时间为影响乙醇产率的主要因素,通过响应面分析得到了较优的工艺条件:底物浓度15%(w/v),酶用量35FPU/g(底物),发酵温度37℃,发酵时间90h。在优化的工艺条件下,乙醇浓度为42.2g/L,达到理论产量的82.6%。和分步糖化发酵(SHF)工艺结果比较,SSF具有更高的生产效率。

The production technology of cellulose ethanol from steam exploded corn stalk by simultaneous saccharification and fermentation （SSF） was studied in this paper.After pretreated by steam explosion,the hydrolysis yield of corn stalk increased to 85.0%.According to the design of Box-Behnken,enzyme amounts,temperature and time were chosen as three important factors,and the optimal conditions were achieved by response surface analysis （RSA）.Result shows that the optimal conditions are enzyme amounts 35FPU/g （material）,temperature37℃,time 96h.Under the optimal conditions,the ethanol concentration can reach to 42.2g/L,an yield of 82.6% （related to theoretical result） was obtained.Further comparison shows that SSF has higher productivity than SHF.