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.