The chemical compositions of lignin, hemicellulose and cellulose are so far unascertained to various lignocellulose in respect to effect of cellulose enzymatic hydrolysis . The novel and environment-friendly gluconic acid (GA) pretreatment technology showed impressive results on the enzymatic hydrolysis of cellulose in various agricultural straws. However, only few of the main reasons or critical issues pertaining to this reaction are known. Therefore, the novel GA pretreatment was carried out to remove hemicellulose from the three representative waste straws under different conditions. Next, for the enzymatic hydrolysis of the residual cellulose fraction in the pretreated straws, some mathematical correlations have been investigated between enzyme accessibility, hemicellulose removal rate, and cellulose crystallinity index. Both linear and nonlinear models were compared using five-parameter logic curve, four-parameter logic curve, and Deming regression. Hemicellulose removal was logically ascribed to be the trigger for cellulose saccharification efficiency during GA pretreatment of these waste straws.
Dandan Zhou,Zhiheng Zhang,Shiyu Zhang,Di Meng,Qiulu Chu,Jing Wang,Shufang Wu,Jinguang Hu
The recalcitrance of softwood towards enzymatic hydrolysis is one of the major bottlenecks hindering its profitable use as feedstock for lignocellulosic biorefinery. This study presents double in-situ lignin modification in an acid-alkaline combinational pretreatment. Results indicated that complete delignification was not essential to achieve theoretical hydrolysis of cellulose. Alternatively, partial lignin removal accompanied by selective modification of the lignin gave rise to significantly inproved ease of enzymatic hydrolysis. Several analyses, including (GPC, 31 P NMR, 2D HSQC NMR, QCM and DLS) were performed to reveal the underlying mechanism of the double in-situ lignin modification in enhancing ease of cellulose hydrolysis. Moreover, detaching behavior of lignin during enzymatic hydrolysis was also elucidated, which provided new insights into understanding the role lignin repolymerization inhibitors and combinational pretreatments played in improving enzymatic digestibility of lignocellulosic biomass.
危险品化学品经营许可证（带存储）