Abstract:

Pretreatment of corncobs is critical for cellulosic ethanol production. In this study, response surface methodology was used to optimize the pretreatment conditions of corncobs, mathematical model of regarding the ethanol concentration as response value was established. The optimizing experiments were established on the basis of BoxBehnken Design. The results indicated that the optimum conditions were 88.6℃ temperature, 19.8 h, of 6.5∶1 liquidtosolid ratio, and 1.86%(v/v) H2SO4 concentration. After such pretreatment, corncobs cellulose content was 53.36%, which was 66.49% higher than the untreated ones, and the hemicellulose removal rate reached to 7758%. The ethanol concentration was 12.4 g/L after simultaneous saccharification and fermentation by SPSC01, which was very close to the predicted value 12.64 g/L. The ethanol concentration could increase to 20.54 g/L, when the added enzyme dosage was 35 FPU/g.

Key words: corncobs, response surface methodology, ethanol, pretreatment, selfflocculating yeast

摘要：

预处理是利用木质纤维素转化生成乙醇的关键步骤。实验基于BoxBehnken试验设计，应用Design Expert 8.0软件对玉米芯预处理条件进行响应面分析，建立以同步糖化发酵终点乙醇浓度为响应值的数学模型，结果表明：最佳预处理条件温度为88.6℃、时间为19.81 h、液固比为6.5、硫酸浓度为1.86%(v/v)。与未预处理的玉米芯相比，经预处理后的固体物料中半纤维素去除率达到77.58%，纤维素含量提高66.49%，利用自絮凝酵母SPSC01进行同步糖化发酵，终点乙醇浓度为12.4 g/L，接近预测值12.64 g/L。当加酶量为35 FPU/g时，发酵终点乙醇浓度可达20.54 g/L。

关键词: 玉米芯;响应面法;乙醇;预处理;自絮凝酵母