Study on biogas production from corn straw pretreated by compound microorganisms

Abstract

The pretreated corn straw is pretreated by Fomes fomentarius, Trichoderma adaptatum and the compound microbial agent of Fomes fomentarius and Trichoderma adaptatum under the same conditions. Then biogas was produced by anaerobic fermentation of pretreated straw. According to the experimental results, it has been found that the straw pretreatment with complex microorganisms can not only promote the process of straw anaerobic fermentation biogas production, but also improve the gas production and gas production efficiency, among which the compound microbial agent pretreatment shows the best effect. Compared with the untreated straw, the degradation of lignin and cellulose in straw pretreated with compound microbial agent is much higher, and the lignin content is decreased from 16.6% to 6.8%, and the cellulose content is decreased from 32.3% to 19.8%. Besides, the gas production of compound microbial agent pretreatment has increased by 14.86%, the gas production time is 6 d earlier, the gas production peak is 17 d earlier, the volume gas production rate reaches 2.008 mL/(mL⋅d), and the gas production rate of raw materials reaches 526.66 mL/g. The straw pretreatment with only Fomes fomentarius also has a good effect. However, the effect of straw pretreatment by Trichoderma adaptatum is poor, which has indicated that straw pretreatment by lignin-degrading strain plays an important role in improving the anaerobic fermentation efficiency of straw.