Bioethanol Production Based on Simultaneous Saccharification and Fermentation of Wheat Straw

The potential of wheat straw as raw materials for ethanol production was investigated. Ethanol cooking at 190 ¿ for 60 min was adopted as pretreatment method for dilute sulfuric acid impregnated wheat straw. The pretreated wheat straw was used as substrate for the production of ethanol by simultaneous saccharification and fermentation (SSF) through orthogonal experiment design in the present study. The in¿uence of different parameters in SSF, such as reaction temperature, substrate concentration, initial medium pH and enzyme concentration, on the ethanol concentration and yield was investigated and the SSF conditions were optimized. The ranking, from high to low, of influential extent of the SSF affecting factors to ethanol concentration and yield was substrate concentration, enzyme loading, initial fermentation liquid pH value, reaction temperature, orderly. The optimum SSF condition was 35¿ for reaction temperature, 100 gl-1 for substrate concentration, 5.0 for initial fermentation liquid pH value, 30 FPUg-1 for enzyme loading. Under the optimum SSF condition, 23.1 gl-1 of the ethanol concentration and 68.2% of the ethanol yield were obtained respectively after 72 h.