响应面法优化玉米秸秆穰发酵燃料乙醇的研究

Optimization of Fuel Ethanol Production by Corn Stalk Pulp Fermentation with Response Surface Methodology

为提高玉米秸秆的综合利用,以玉米秸秆穰为发酵原料进行乙醇固态发酵,通过单因素试验考察pH、发酵温度、发酵时间、酶浓度4个因素对玉米秸秆穰发酵燃料乙醇的影响,在单因素试验基础上利用响应面法建立玉米秸秆穰发酵乙醇产量的数学模型。根据此模型进行工艺参数优化,以乙醇生成率为指标,确定玉米秸秆穰发酵燃料乙醇的最佳工艺条件:pH 5.1、发酵温度39℃、发酵时间28 h和酶浓度45 U/g。在此条件下,玉米秸秆穰发酵燃料乙醇的理论产率为0.2490 g/g,实际得率为(0.2376±0.0007)g/g,生产1 t燃料乙醇需要4.002 t的玉米秸秆穰干料,玉米秸秆穰发酵燃料乙醇的理论转化率为95.77%,进行3组验证试验,乙醇转化率实测值为(95.44±0.28)%,验证了数学模型的有效性,为提高以玉米秸秆穰为原料发酵燃料乙醇提供参考。

In order to improve the comprehensive utilization of corn stalk,pulp of corn stalk is used as raw material for solid-state fermentation of ethanol.The effects of pH,fermentation temperature,fermentation time and enzyme concentration on fuel ethanol production by corn stalk pulp fermentation are investigated by single factor experiment.Based on the single factor test,a mathematical model for ethanol production by corn stalk pulp fermentation is established by response surface methodology.Based on the model,the process parameters are optimized.The conversion rate of ethanol is taken as the index,and the optimum enzymolysis conditions for fuel ethanol production by corn stalk pulp fermentation are determined:pH 5.1,fermentation temperature 39℃,fermentation time 28 h and enzyme concentration 45 U/g,under which the theoretical yield of fuel ethanol production by corn stalk pulp fermentation is 0.2490 g/g dry pulp of corn stalk,and the actual yield is(0.2376±0.0007)g/g dry pulp of corn stalk.According to it,it needs 4.002 t dry pulp of corn stalk to produce 1 t fuel ethanol,and the theoretical prediction conversion rate of ethanol by corn stalk pulp fermentation is 95.77%.Three groups of validation tests are carried out,and the actual ethanol conversion rate reaches(95.44±0.28)%,which verifies the validity of the mathematical model.The results of the optimal technology will provide a reference for improving fermentation of fuel ethanol with pulp of corn stalk as raw material.