This study was conducted to investigate the possibility of
enhancing ethanol production yield by applying a twin-screw
extruder under low temperature and sodium hydroxide conditions
for biofuel production. Barley straw was pretreated with
sodium hydroxide in the twin-screw reactor and pretreated barley
straw in optimal conditions was fermented using the simultaneous
saccharification and fermentation (SSF) process. Since cellulase is
inhibited by glucose as it is formed, rapid conversion of the glucose
into ethanol by yeast results in faster rates, higher yields,
and greater ethanol concentrations than possible for separate
hydrolysis and fermentation [18,20]. Also, we applied response
surface methodology (RSM) to delineate the effects of five levelthree
factors and their reciprocal interactions on pretreatment to
optimize pretreatment conditions. We calculated the biomass to
glucose ratio (BTGR) and the biomass to ethanol ratio (BTER) to
evaluate the efficiency of bioethanol production from lignocellulosic
biomass. The specific surface area of the pretreated biomass
was investigated, as twin-screw extrusion has a good effect on
dispersibility. Additionally, the optimum dosage of enzymes and
pretreated biomass for the SSF process were determined for efficient
bioethanol production.