Dilute acid pretreatment, enzymatic saccharification and fermentation of elephantgrass and sudangrass to ethanol

摘要

In order to evaluate ethanol production potential of elephantgrass, sudangrass and their combined material, dilute-acid pretreatment, enzymatic hydrolysis, and fermentation of the biomasses were investigated in the study. Ground biomasses at a solid loading of 12.5%(w/v) were pretreated with H_2SO_4 at concentration of 0.5%, 1%, 1.5%(w/v), and enzymatic hydrolysis was performed using commercial cellulose, and fermentation was investigated with Candida tropicalis and S. cerevisiae. Monomeric sugars, lignin and ash content in the prehydrolyzate, and ethanol yields were analyzed in the experiment. The yield of xylose from the hydrolyzate was between 56.96-100.34mg g~(-1). The glucose concentration in the prehydrolyzate was 21.31-57.46mg g~(-1) and the maxim yield of total sugars in elephantgrass and sudangrass was 141.73 and 124.177 mg g~(-1) respectively. And the release of sugars after enzymatic hydrolysis was 139.15-195.94mg g~(-1). The ethanol yield per unit biomass was comparable to those reported from other agriculture biomass: 0.09-0.12g g dry~(-1).The mixture biomass gave a 16.36% higher ethanol yield than others. The results suggested that the two species are suitable for ethanol production. And the combination of sudangrass with elephantgrass had a positive effect on the ethanol yield.