稻秸不同粒度对沼气发酵浮渣结壳层的影响

Influence of Different Straw Particle-size on Scum Crusting in Anaerobic Fermentation

秸秆沼气工程中因原料上浮易产生料液分层结壳的现象,从而影响产气效率。文章以稻秸为原料,采用批式试验,研究不同粒度对沼气发酵结壳层特性的影响。结果表明:粒度为5 cm,2 cm和过筛10目时,结壳层密度随沼气发酵时间增加而增加,随粒度的减小而增大;到36 d,35 d和20 d,结壳层进入稳定期,密度不再增加,最终分别为54.84 g·L-1,62.67 g·L-1和99.71 g·L-1。但破壳强度随着粒度减小而减小,发酵60 d,分别为3.14 k Pa,2.10 k Pa和1.24 k Pa。综上所述,在一定粒度范围内,粒度越小越有利于减少破壳能耗。

The crusting was likely to form upon fermentation liquor due to the characteristic of floating, and significantly re- duced the biogas yield in the anaerobic digestion of rice straw. In this study, the influence of different particle sizes of rice straw on the crust characteristics was investigated by batch experiments. Results showed that scum layer density increased with the increase of time and the decrease of the particle size. The scum layer reached the stable stage after 36 d, 35 d and 20 d for particle sizes of 5 cm, 2 cm and 10 meshes sieved particles, respectively, and the incrustation layer density were 54.84, 62.67 and 99.71 g · L-1 respectively. After 60 d, breaking strength were 3.14, 2.10 and 2.10 kPa, respective- ly, which were decreased with the decrease of the particle size. In short, the smaller the particle size was, the more benefits were gained to reduce the thickness of scum layer and the breaking energy consumption in a certain range of particle size.