Study on the Structural Changes of Hemicellulose of Corn Stover during Ethanol Pretreatment
In this paper,corn stover was chosen as raw material and ethanol was used to pretreat it at the following condition:retention time 60 minutes at 160℃,S/L 1∶ 8,ethanol concentration 50％.Then hemicellulose was extracted and purified from corn stover before and after ethanol pretreatment respectively.The results of corn stover's component analysis showed that during pretreatment 66.6％ lignin and 61.3％ extractives were removed,part of cellulose and hemicellulose were also degraded.According to the results,it was concluded that hemicellulose from corn stover was composed mainly with xylan,then arabinan,with trace amount of glucan and glactan.Besides,lignin and uronic acid were also present.The results of hemicellulose's component analysis showed that glucan from hemicellulose was the easiest to be degraded,then arabinan,xylan was the most stable in the process of ethanol pretreatment.And the content of uronic acid was not changed obviously during ethanol pretreatment.From the analysis of FT-IR,UV-V is spectrum and liquid chromatogram,it was found that hemicellulose from corn stover after ethanol pretreatment contained more-CH3 and-CH2-units,indicating that hemicellulose was degraded to some extent during the pretreatment process.In addition,a decrease in molecular weight and increase in polydispersity of hemicelluloses were the result of the degradation of hemicelluloses during ethanol pretreatment.
国家科技期刊平台
NSTL
万方数据
维普
