鸡粪与玉米秸秆混合发酵沼气产量影响因子研究

Factors Affecting Biogas Yields of Manure-Straw Mixture

为探索物料配比、发酵温度、初始发酵浓度与产气量之间的关系以及各因素的重要性,通过自行研究设计的可控性恒温发酵装置,以玉米秸秆和鸡粪混合物为原料,在20、25、30、35、40℃下按不同干物质配比及初始发酵浓度分别进行厌氧发酵,分析不同物料配比、发酵温度、初始发酵浓度对发酵过程中pH值、累积产气量和TS产气量的影响,并对影响沼气发酵的各因子进行重要性排序。结果表明,物料配比、初始发酵浓度和发酵温度是影响产气量的重要因子,鸡粪与玉米秸秆2∶1、初始发酵浓度为20%时沼气产量最大;发酵温度在35℃左右时,各处理均能达到最优发酵效果;各因子对沼气产量影响的重要性依次为温度>初始发酵浓度>配比。因此,适当调整发酵温度以及初始发酵浓度将会有效提高沼气发酵利用效率。

To study the importance of material mixture ratio, temperature, initial fermentation concentration, biogas production and also the relationship among them, a simulation experiment using self-designed constant-temperature anaerobic fermentation equipment was conduct- ed in indoor conditions. In the present study, chicken manure and rice straw mixture with different ratio and initial concentration at 20 ℃, 25 ℃, 30 ℃, 35℃, 40 ℃ was used as the digestion material, aiming at investigating the biogas production of chicken manure and corn straw mixture, and analyzing the effect of material mixture ratio, initial fermentation concentration and the temperature on the pH value, cumulative biogas production and biogas yield of TS, and also sequencing their importance in the fermentation. The results showed that the mixture ratio, initial fermentation concentration and temperature affected the biogas production significantly. The highest biogas production was found at 2：1 of manure-corn straw when the initial fermentation concentration was 20%; and 35℃ was the best temperature for fermentation. The stepwise aggression showed that the importance of temperature, initial fermentation concentration, material mixture ratio on biogas production was ranked by an order：temperature〉initial fermentation concentration〉material mixture ratio. Therefore appropriate adjustment of tempera- ture and initial fermentation concentration can increase the efficiency of biogas production.