Hydrolysis Of Lignocellulose By Dilute Acid Pretreatment And Enzymatic Saccharification

In this paper, the hydrolysis of lignocellulose by two steps was studied. The first step is the hydrolysis of hemicellulose for xylose from bagasse pith by dilute acid hydrolysis at low temperature and for furfural from corncob with dilute acid as catalyst. The second step is the enzymatic hydrolysis of cellulose including the investigation and optimization of the enzymatic hydrolysis process for obtaining the maximum glucose yield.In order to get the maximum xylose yield from bagasse pith hydrolysis, the main factors of acid hydrolysis was analyzed, and the optimum conditions for depolymerization of hemicellulose bagasse pith was obtained at liquid to solid ratio10:1, reaction temperature120℃, the concentration of hydrochloric acid1.0%, retention time16min, where the maximum xylose yield was84.41%(26.39g/L), glucose yield was1.72g/L (3.42%), and the fermentation inhibitors were1.05g/L acetic acid and0.98g/L furfural. It could be concluded that there was little xylose decomposition and cellulose degradation, and the hydrolysate was good for subsequent fermentation process. In the continuous process of corncob hydrolysis, the influence of main factors and their interaction on the yield of furfural was analyzed, and the maximum furfural total yield47.07%was obtained.The enzymatic hydrolysis of hemicellulose residue was to achieve a multi-stage utilization of raw material. The maximum glucose yield88.38%(71.56g/L) was obtained at solid enzyme dosage24FPU/g, solid content10%, temperature50℃, with a small amount of cellobiase.