响应面法优化Fenton氧化预处理杨木的研究

Optimization of Fenton Oxidation Pretreatment of Poplar by Response Surface Methodology

在单因素实验的基础上,以Fenton氧化预处理得率和纤维素酶解过程中葡萄糖得率为考察指标,通过中心组合-响应面法优化得到Fenton氧化预处理杨木的最佳条件为:H2O2/FeCl3(体积比)=10%、pH值2.5、FeCl3浓度50 mmol/L;在此条件下,葡萄糖得率可达51.4%。响应面分析表明,FeCl3浓度对Fenton氧化预处理杨木葡萄糖得率的影响最显著,H2O2/FeCl3对脱木质素影响最显著。Fenton氧化预处理脱除了杨木中部分木质素,但木质素的脱除率与葡萄糖得率之间没有直接关系。另外,Fenton氧化预处理后,杨木纤维素的结晶度和比表面积分别提高了12.8%和80.2%,其中比表面积的提高有利于促进纤维素的酶降解,这也是Fenton氧化预处理提高杨木酶解性能的机理之一。

In this study,on the basis of single factor experiment and response surface method,the optimum conditions for Fenton oxidation pretreatment of poplar for bioethanol production were obtained:H2O2/FeCl3=10%,pH value 2.5,FeCl3 concentration 50 mmol/L,and the yield of glucose under these conditions was 51.4%.Analysis by response surface showed that FeCl3 concentration had the most significant effect on the yield of glucose,H2O2/FeCl3 had the most significant effect on delignification ratio.Component analysis of pretreated poplar indicated that lignin was removed partly during Fenton oxidation pretreatment.But there was no correlation between lignin removal and cellulose conversion.Furthermore,the cellulose crystallinity and specific surface area of pretreated poplar were increased by 12.8% and 80.2%,respectively,compared with the control.The increased specific surface area is beneficial to the enzymatic degradation of cellulose,which is one of the mechanisms of improving enzymatic degradation of poplar with the help of Fenton oxidation pretreatment.