Effects of aerobic fermentation pre-treatment on dry anaerobic fermentation gas production and its energy loss

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℃). But when aerobic fermentation temperature significantly higher than anaerobic fermentation (55℃), 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.