Abstract: Four main non-lignin constituents in corn stover, including cellulose, hemicellulose, hot water extractives, and ethanol extractives, were prepared and pretreated with dilute sulfuric acid, respectively. Their water soluble degradation products profiles were analyzed by high performance liquid chromatography detection. During dilute sulfuric acid pretreatment, glucose, formic acid (FA), levulinic acid (LA), and 5-hydroxymethylfurfural (HMF) were released from cellulose degradation. Xylose, arabinose, glucuronic acid, galacturonic acid, acetic acid (AA), and furfural were released from hemicellulose degradation. The hot water extractives degradation produced glucose, xylose, arabinose, FA, AA, LA, HMF, and furfural, and only trace of glucose, xylose, AA, LA, and HMF were found in the hydrolyzates of ethanol extractives. Totally, FA, LA, and HMF mainly originated from cellulose degradation at the yields of 1.4%, 2.7%, and 2.2%, while AA and furfural came from hemicellulose degradation at the yields of 3.1% and 7.8% on the basis of corn stove weight, respectively. Orthogonal tests showed that the AA production was significantly affected by the concentration of sulfuric acid, while the FA, LA, HMF, and furfural formations were seriously affected by the pretreatment temperature.

Key words: corn stover, non-lignin constituents, dilute sulfuric acid pretreatment, degradation reaction, profiles of degradation chemicals