关键词: 乙醇, 同步糖化发酵, 玉米秸秆, 真空分离

Abstract: The effects of various simultaneous saccharification fermentation (SSF) technologies on ethanol yield from cellulose were investigated. Using steam-exploded corn stalks as raw materials, five SSF technologies, including traditional SSF, SSF combined with preliminary enzymatic hydrolysis,fed-batch SSF coupled with preliminary enzymatic hydrolysis,SSF united with preliminary enzymatic hydrolysis coupling with vacuum separation and fed-batch SSF associated with preliminary enzymatic hydrolysis coupling with vacuum separation,were used for decomposition of the stalks. By comparing the fermentation process with higher solid concentration including 15% (mass) and 30% (mass), it was found that the fed-batch SSF combined with preliminary enzymatic hydrolysis is an effective way for raising substrate concentration. However, higher substrate concentration may lead to decrease of final ethanol yield. Moreover, SSF coupled with vacuum separation can weaken the product inhibition, and increase the ethanol yield. The ethanol productivity by the fed-batch SSF associated with preliminary enzymatic hydrolysis coupling with vacuum separation is 0.40 g·L^-1·h^-1,the highest value obtained,indicating that this technology can be a potential new technology.

Key words: ethanol, simultaneous saccharification and fermentation, corn stalk, vacuum separation