搅拌频率对粪秸高含固率连续产甲烷反应器启动性能的影响

Effect of Stirring Frequency on Startup Performance of Continuous Reactor with High Solid Content of Rape Straw and Dairy Manure

为实现粪秸清洁化、高效化厌氧产甲烷,试验在自制的纤维质物料高含固率连续产甲烷反应器中,以油菜秸秆和牛粪为原料,在中温条件(37℃±1℃)下研究了2个搅拌频率(8 r·min^(-1)和35 r·min^(-1))对该反应器启动阶段产甲烷效率的影响。结果表明,在仅添加牛粪和出料回填的条件下,低频率搅拌反应器(R1)和高频率搅拌反应器(R2)均能在5 d后稳定产气,产甲烷效率没有显著差异。在牛粪和秸秆混合进料、含固率分别为10%和15%的条件下,低搅拌频率会提高反应器甲烷产率,且会使物料在反应器内产生更加明显的空间异质性,反应器上部VFAs浓度显著高于下部。当TS=10%,进料VS为0.46 kg·d^(-1)时,R1的平均比甲烷产率和容积甲烷产分别为123.54 L·kg^(-1)VS_(added)和1.13 L·d^(-1),比R2高11.08%和10.78%;当TS=15%,进料VS为0.69 kg·d^(-1)时,R1的平均特殊甲烷产率和容积甲烷产率分别为94.84 L·kg^(-1)VS_(added)和1.31 L·d^(-1),比R2高11.68%和11.82%。上述研究结果为该反应器利用粪秸在高含固率条件下实现快速启动和高效产甲烷提供了理论依据和工艺参数。

In order to obtain clean and efficient methane production from straw and manures, the home-made reactor was fitting to continuous anaerobic digestion for high solid content of lignocellulosic feedstock and was adopted to carry out the startup experiment. Effect of the two different stirring frequency （ 8 r · min-1 and 35 r· min - 1 ） on the methane production rate at the startup phase with rape straw and diary manure as substrate were investigated under the temperature of 37℃±1℃. The results showed that both the R1 with the low frequency stirring and R2 with the high frequency stirring could pro- duce biogas stably after 5 days＇ startup with sole dairy manure as feedstock and backfilling of discharges, and the methane production rate had no significant difference between them. With the mixture of rape straw and diary manure as substrate at TS concentration of 10% and 15%, the low stirring frequency could improve＇methane production rate, and the obvious spa- tial heterogeneity of feedstock in the reactor was formed. Meanwhile, the VFAs concentration of up-layer in the reactor was significant higher than that of bottom. Under the TS concentration of 10% and VS loading of 0.46 kg·d-1 , the average specific methane production rate （SMPR） and volumetric methane production rate （VMPR） of R1 were 123.54 L · kg-1 VS.aded and 1.13 L· d -1 respectively, which were 11.08% and 10.78% higher than that of R2 respectively. Under the TS concentration of 15% and VS loading of 0.69 kg· d-1 , the average SMPR and VMPR of R1 were 94.84 L· kg-1VS,dd＋d and 1.31 L· d-1 respectively, which were 11.68% and 11.82% higher than that of R2 respectively.