Zhang Wei, Wang Zebin, Guo Hongyu, Li Libo, Zhang Minglu, Zhang Wen, Sun Xiaoguang, Sun Shixuan, Kou Congliang, Zhao Weizhong
China University of Mining and Technology, Xuzhou 221018, China.
PetroChina Coalbed Methane Company Limited, Beijing 100028, China.
ACS Omega. 2022 Aug 23;7(35):31138-31148. doi: 10.1021/acsomega.2c03331. eCollection 2022 Sep 6.
The combined anaerobic fermentation of coal and straw can increase the production of biogas. To explore the mechanism of adding corn straw to increase methane production, coal with different metamorphic degrees and corn straw were collected for biogas production simulation experiments under different substrate ratios. The changes in liquid products, the structure of lignocellulose in corn straw, and microbial evolution were monitored. The results showed that the combined fermentation of bituminous coal A with corn straw and bituminous coal C with corn straw at a mass ratio of 2:1 each ((AC-2) and (CC-2)) and that of bituminous coal B and corn straw at a mass ratio of 3:1 (BC-3) had the best gas production, and methane yields reached 17.28, 12.51, and 14.88 mL/g, respectively. The fermentation liquid had organic matter with more types and higher contents during the early and peak stages of gas production, and fewer types of organic matter were detected in the terminal stage. The degradation of lignocelluloses in the corn straw of AC-2 was higher. With the increase in fermentation time, the carbohydrates in the fermentation system increased and the degradation rate of cellulose decreased gradually. The abundance of genes related to nitrate reduction gradually increased, while that of sulfate reduction was on the contrary. Bacteria in the cofermentation system mainly metabolized carbohydrates. During cofermentation with high metamorphic coal, corn straw would be preferentially degraded. The structure of the archaea community changed from and to .
煤与秸秆的联合厌氧发酵能够提高沼气产量。为探究添加玉米秸秆提高甲烷产量的机制，收集了不同变质程度的煤和玉米秸秆，在不同底物比例下进行沼气生产模拟实验。监测了液体产物的变化、玉米秸秆中木质纤维素的结构以及微生物的演化。结果表明，烟煤A与玉米秸秆、烟煤C与玉米秸秆质量比均为2:1（分别记为(AC - 2)和(CC - 2)）以及烟煤B与玉米秸秆质量比为3:1（BC - 3）时产气效果最佳，甲烷产量分别达到17.28、12.51和14.88 mL/g。发酵液在产气初期和高峰期含有更多种类和更高含量的有机物，而在末期检测到的有机物种类较少。AC - 2中玉米秸秆的木质纤维素降解程度更高。随着发酵时间的增加，发酵体系中的碳水化合物增加，纤维素降解率逐渐降低。与硝酸盐还原相关的基因丰度逐渐增加，而硫酸盐还原相关基因的丰度则相反。共发酵体系中的细菌主要代谢碳水化合物。在与高变质煤共发酵时，玉米秸秆会优先被降解。古菌群落结构从 变为 。
