Conversion of Wheat Straw to Ethanol by Simultaneous Saccharification and Fermentation

Ethanol from lignocellulosic biomass is an attractive substitute for oil with low net carbon dioxide emission. This work investigated the potential of wheat straw as raw materials for ethanol production. Ethanol cooking at 190°C for 60 min was adopted as pretreatment method for acetic acid impregnated wheat straw. From the pretreated wheat straw, ethanol was produced by simultaneous saccharification and fermentation (SSF) in the present study. The influence of process 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 optimization of the SSF conditions was attempted using a orthogonal experiment design. The optimum reaction temperature, substrate concentration, initial pH, amount of added enzyme for the SSF of wheat straw were 35°C, 100 gl^-1, 5.0 and 30 FPUg^-1, respectively. Under the optimum conditions, 18.8 gl^-1 of the ethanol concentration and 43.5% of the ethanol yield were obtained respectively after 72 h.