农作物秸秆的厌氧消化试验研究

Study on Anaerobic Digestion of Straw Stalk

采用厌氧消化技术,研究了秸秆在中温、高温及环温条件下的生物气产量、发酵液乙酸浓度及甲烷含量的变化情况,比较了不同条件下TS和VS的去除率及产气率。结果显示,在试验的各个温度条件下,秸秆的厌氧消化都可以进行,在高温时干物质产气率可达到0.24m3·kg-1,比环温及中温时产气率分别提高42%和21%,但高温引起的酸化会使得系统的正常运行受到影响,中温和环温的甲烷含量在第8d都可以达到50%以上,系统启动快且在试验期间运行稳定,因此从能量投入产出、产气稳定性等因素综合考虑,中温厌氧消化是比较理想的农作物废弃物的处理方法。

The biogas yield, concentration of acetic acid and percentage of methane during anaerobic digestion of straw stalk under different temperatures （thermophilic, mesophilic and ambient） were investigated. The removal rates of total solid （TS） and volatile solid （VS） and biogas yield per kilogram were compared among different treatments. The results showed that the anaerobic digestion of straw stalk in every temperature can successfully progress, the biogas conversion rates at thermophilic temperature reached 0.24 m^3· kg^-1 TS, increasing by 42% and 21% compared to that at mesophilic and ambient digestion respectively, but acidification in thermophilic anaerobic digestion had serious effect on the normal function of the system. The percentage of methane in mesophilic and ambient digestion was up to over 50% on the 8th day. Considered the energy generating and consuming and biogas production, the anaerobic digestion under mesophilic condition, with quickly starting up and steadily functioning, could be one of the effective approaches for deposal of straw stalk.