外源氢气连续导入沼气发酵系统原位合成甲烷的实验研究

In Situ Synthesis of CH_(4) in an Anaerobic Fermentation System by Continuous Introduction of Exogenous H_(2)

搭建能实现外源H_2连续通入沼气厌氧发酵体系的小试装置,达到原位转化CO_2合成CH_4的目的。利用秸秆进行中温(35℃)和高温(55℃)厌氧发酵,探索外源H_2的通入对发酵过程的影响。结果表明:外源H_2的通入使得沼气产量和沼气中CH_4相对含量明显提高,但沼气产量不与外源H_2通入量成正比,外源H_2通入量以CO_2产生量的5倍为宜,此时外源H_2转化率也达到最高,平均约为86%(中温发酵)和91%(高温发酵),消耗的外源H_2几乎全部转化为CH_4;高温发酵比中温发酵更具优势。

Experimental system was set up for continuous introduction of exogenous H2into a biogasanaerobic fermentation system to convert CO2in the biogas into CH4in situ.Anaerobic fermentation under bothmesophilic and thermophilic conditions were carried out using straw,and the effect of exogenous H2on thefermentation process was explored.The results show that both biogas production and CH4relative contentincrease significantly after H2addition,but biogas production is not proportional to exogenous H2flow rates.The optimal exogenous H2flow rate is5times of CO2production,and the average conversion of exogenous H2is about86%for mesophilic fermentation and91%for thermophilic fermentation under such conditions.Almostall exogenous H2consumed is converted to methane.The results show that thermophilic fermentation is moreadvantageous than mesophilic fermentation.