发酵液循环对互花米草沼气发酵的影响

Effect of Fermenting Liquid Circulation on Biogas Fermentation of Spartina aterniflora

互花米草产沼气属于固态发酵,发酵过程介质传递效果差,并且很难通过传统搅拌技术得到克服。本文通过试验,研究发酵液循环促进互花米草沼气发酵过程中介质传递,提升发酵效率的可能性。试验设置发酵液循环和无循环两组,反应温度控制在(35±2)℃,反应周期45天。结果表明,发酵液循环对互花米草沼气发酵的产气速率、总产气量和原料利用率等方面均有较大的积极效果。发酵液循环组第9天就达到产气峰值,比无循环组早13天;发酵液循环组总产气量达到49270 m l,比无循环组多6125 m l,高出14.17%;日累积达50%和60%总产气日期,发酵液循环组比无循环组分别前移8天和7天。产气趋于完成时开始出现维持性低水平产气,其出现的时间发酵液循环组在第23天,比无循环组提前4天。此外,发酵液循环组的发酵过程也比无循环组相对稳定和呈规律性。

Biogas fermentation of Spartina aterniflora belongs to solid fermentation, so efficiency of medium transfer is low in the process, and difficult to overcome with stirring. The experiments were made to investigate the possibility of improving fermentation efficiency through ameliorating medium transfer by fermentation liquid circulation. The result showed that fermentation liquid circulation could obtain higher biogas production rate and total biogas yield. The daily biogas production peak of circulation group achieved on the 9th day, which was 13 days earlier than the contrast. The total biogas yield of circulation group was 49270 ml, which was 6125 ml higher than the contrast. And the circulation group reached the 50% and 60% cumulative biogas production was 7 and 8 days earlier than contrast, respectively. In addition, the fermentative process of circulation group was relatively stable and regular compared with contrast.