牛粪搅拌式固定床沼气发酵条件的优化

Optimization of Fermentation Conditions of Mixing Type Fixed Bed Reactor Using Cow Manure as the Feedstock

以牛粪为沼气发酵原料,利用连续搅拌式反应器(Continuous stirred tank reactor,CSTR)和碳纤维载体构建搅拌式固定床反应器,研究料液浓度(TS)、碳氮比(C/N)、温度、p H、水力停留时间(HRT)和搅拌转速对甲烷产量的影响,通过响应面设计进行回归分析,结合满意度函数确定牛粪搅拌式固定床厌氧发酵工艺的最佳参数。研究结果表明最佳工艺条件为:TS 8%,C/N 25∶1,温度39℃,pH 7.5,HRT 10 d。验证分析表明,模型预测值与试验值相吻合(偏差2.27%),模型拟合度较好。

Mixing type fixed bed reactor was built combining the Continuous Stirred Tank Reactor（CSTR）and carbon fiber carrier.The effects of total solid（TS）,carbon and nitrogen ratio（C/N）,temperature,pH,hydraulic retention time（HRT） and stirring speed on biogas production were investigated using cow manure as the feedstock. According to the analysis of response surface method logy and desirability function,the optimum conditions for biogas yield was as follows：materials density 8%,hydraulic retention time 10 d,temperature 39 ℃,pH 7.5,carbon and nitrogen ratio 25∶1. After model validation,experimental and predictive value was consistent and the test result and the relative deviation was 2.27%.