Experimental study on gas production from Zhaotong lignite degradation by microbial community in mine water

In order to explore the potential of microbial degradation and gas production in Zhaotong lignite, anaerobic methanogenic bacteria were collected from the coal mine water of Baode coalbed methane well in Xinzhou, Shanxi Province. The characteristics of coal, liquid, bacteria and gas in the biosimulated gas production process were analyzed by means of GC-MS, Fourier infrared spectrometer and high-throughput sequencing. The experimental research results show that the gas production cycle of Zhaotong lignite is 49 days, the cumulative gas production of the experimental group is 10.76 mL/g, and the cumulative gas production of the control group (without coal added) is 13.83 mL. The abundance of volatile fatty acids and methyl compounds in the simulated biogas production system was significantly higher than that in the control group. The absorption peaks of hydroxyl and oxygen-containing functional groups in lignite were weakened after biological gas production. The analysis of microbial community structure shows that the enriched anaerobic methanogenic bacteria are mainly Firmicutes, Bacteroidetes, Clostridia, Synaptites, and Proteobacteria, while Petrimonas, W27, Soehngenia, Proteiniphilum and other bacterial genera are important functional bacteria in the degradation process of lignite.