RESPONSE SURFACE OPTIMIZATION OF ENZYMATIC HYDROLYSIS PROCESS OF WET OXIDATION PRETREATED WOOD PULP WASTE

摘要

The bioconversion of lignocellulosic waste (known as wood pulp waste) from the pulping production process into fermentable sugar is a promising way to implement the integrated forest biorefinery concept. The enzymatic hydrolysis process is a feasible step for the bioconversion process. In this paper, the enzymatic hydrolysis process was optimized by a two-level three factor (2 3) full factorial central composite design through varying temperature, time and enzyme loading. The results showed that the optimum conditions were: temperature of 50 degrees C, time of 48 h and enzyme loading of 35 FPU/g substrate, which gave an 85.4% of cellulose conversion ratio. Additionally, the X-ray diffraction (X-RD) and scanning electronic microscopy (SEM) of the substrates showed decreases of the crystallinity index and degradation of cellulose after enzymatic hydrolysis. The optimization of enzymatic hydrolysis provides an economical and efficient approach to implement the bioconversion process of pretreated wood pulp waste.