好氧预处理对干法沼气发酵产气量的影响及能量损失

摘要

To make clear the impact of different aerobic fermentation pre-treatments to gas production and energy loss of dry anaerobic fermentation, the experiments were done in controllable constant temperature fermentation device with material of cow dung and mixed straw. The energy loss was also analyzed. The results indicated that aerobic pre-treatment had significant effect on gas production. The longer time and the higher temperature of aerobic fermentation pre-treatment, the more gas production and energy was lost. The energy loss of aerobic fermentation pre-treatment was better when the temperature of aerobic fermentation approached to the anaerobic (35 °C). But when aerobic fermentation temperature significantly higher than anaerobic fermentation (55°C), it would cause a great energy loss. Therefore, it was important to control the time and temperature of aerobic fermentation on membrane covered trough bioreactor. In order to reduce the gas production and energy loss, once it reached the required temperature, the system should be immediately convert to anaerobic fermentation state.%研究好氧发酵预处理对干法沼气发酵产气效果的影响及能量损失情况,是以好氧发酵升温为预处理方式的干法沼气工程经济运行的重要依据.该文采用恒温沼气发酵装置,以牛粪及少量混合秸秆粉作为发酵原料,研究了不同好氧发酵预处理条件下,干法沼气发酵的产气效果并对其能量损失情况进行了分析探讨.结果表明:以牛粪为主要发酵原料时,好氧预处理对物料干法沼气发酵的产气量有较明显影响,随着好氧发酵时间增加和温度提高,总产气量减少,能量损失增大；好氧发酵预处理温度与沼气发酵温度相同(均为35℃)时,能量损失较少,好氧发酵升温法合理；好氧发酵预处理温度(55℃)显著高于沼气发酵温度,好氧发酵升温法会带来较大能量损失.因此,在对覆膜槽生物反应器操作时,应准确把握好氧发酵的时间和温度,一旦达剑所需温度,应立即转入沼气发酵,以提高沼气产量,减少能量损失.