响应面法优化猪粪和玉米秸秆混合厌氧发酵产沼气工艺

摘要

The effects of feces to straw ratio, fermentation temperature and fermentation concentration on biogas production with mixed pig manure and corn straw were investigated by Box-Behnken designed experiment. The process parameters were optimized by response surface methodology (RSM). The results showed that the quadratic regression mathematics model established according to experimental data had highly significant (P < 0.0001) , in which the correlation coefficient R2 was 0. 9866. This illustrated that the predicted value fit the experimental value very well. The optimum process parameters of this mixed pig manure and com straw fermentation were obtained through inverse matrix of quadratic regression mathematic model, which were as follows: the 30% of corn straw (dry matter) , fermentation temperature of 35℃ and substrate concentration of 12.74%. Under these conditions, the predicted gas production was 291.8 mL ? gTS-1, while the experimental value was 288.5 mL ? gTS -1, and the relative deviation was 1.14%. Therefore, it is feasible and reliable that the response surface methodology ( RSM) could be used for optimizing the biogas production process, and could well predict the biogas productivity.%利用中心组合设计试验考察粪秸比、发酵温度和发酵底物浓度3个因素对猪粪和玉米秸秆混合厌氧发酵产沼气的影响,运用响应面法对其工艺参数进行优化.研究结果表明,根据试验数据建立的二次多项式数学模型具有高度显著性(P ＜0.0001),相关系数R2=0.9866,说明预测值和试验值之间具有很好的拟合度.通过对二次回归数学模型解逆矩阵得到粪秸混合厌氧发酵产沼气的最优化条件为:粪秸比(玉米秸秆干物质占发酵原料干物质的质量分数)为30％,发酵温度为35℃和发酵底物浓度为12.74％.在此条件下,粪秸混合厌氧发酵的沼气产率的预测值为291.8 mL·g-1TS,试验值为288.5 mL·g1TS,二者相对偏差为1.14％.因此,利用响应面分析法进行粪秸混合厌氧发酵产沼气工艺参数的优化是可行可靠的,可以较好地预测沼气产率.