【摘要】 降低沼气中CO2的体积分数是提高沼气利用效率的重要途径.分别以营养液和水稻秸秆作为发酵底物,在发酵瓶(500mL)中利用外源H2和CO2厌氧发酵原位合成CH4.实验探索发酵温度、外源气体组成(H2与CO2体积比)对发酵过程中的产气规律和组成的影响,以确定适宜的反应条件;根据不同条件下食氢产甲烷菌利用H2和CO2的发酵表现,解析沼气中各组分的变化规律.沼气中CH4的相对体积分数随着温度、外源气体组成(H2与CO2体积比)的升高而升高;以营养液为底物的厌氧发酵中,外源氢气的引入能明显提高厌氧发酵沼气产量和CH4的体积分数,外源气体H2与CO2的体积比以5∶1为宜,发酵适宜的温度在55~65℃之间.以秸秆为底物的厌氧发酵中,温度以55℃为宜,以纯H2作为外源气为宜,流量为180mL/(L·d)的条件下,沼气中CH4相对体积分数达到75.5%.更多还原

【Abstract】 Reducing the content of carbon dioxide in biogas is an important way to promoting the utilization of biogas.The exogenous H2 and CO2 were used to synthesize CH4 in-situ in a fermentation bottle(500 mL)based on taking nutrient solution or rice straw as a substrate respectively.The effects of parameters such as temperature and exogenous H2 proportion(H2/CO2)on the biogas production and its components were investigated to determine the suitable technological conditions.The change laws of the biogas contents and production rate were discussed according to the performance of M.thermautotrophicus deltaH using H2 and CO2under different conditions. With the increasing of temperature and H2 proportion(H2/CO2),the content of methane increased.In the anaerobic fermentation process with nutrient solution as the substrate,the addition of exogenous gas can promote the content of methane and also the production of biogas.The optimum temperature was between 55-65 ℃ and exogenous gas ratio(H2/CO2)was 5∶1.Pure H2 was suitable exogenous gas in the anaerobic fermentation with straw as a substrate.The appreciate temperature is 55 ℃ and H2 flow is 180mL/(L·d)under which the relative methane content in biogas could reach 75.5%.更多还原