Inhibitory effects of three fungi on active microstructure in the oxidation process of lignite coal

Abstract

To investigate the effect of microorganisms derived from coal on the natural oxidation process of coal. Three fungi strain were isolated from the Shengli lignite in Inner Mongolia, China. After two rounds of domestication, these strains were separately reacted to coal. Results indicate that microorganisms have a reduction in S content was observed. The influence of the Penicillium chrysogenum strain on the contents of N, O, Al and S was particularly notable. The experimental microorganisms contributed to a decrement in the peak area of OH–O and the content of oxygenated functional groups. Specifically, the Aspergillusustus strain eliminated the vibration peak of C=O in coal. The impact of microorganisms on methylene and methyl was crucial, but it did not alter the dominance of methylene in fatty hydrocarbons. The characteristic temperatures and endothermic heat of the coal increased. The Bjerkandera adusta strain resulted in a reduction of 25.17 J/mg in the early-stage endothermic heat and 42.62 J/mg in the slow exothermic stage heat release. Microorganisms can increase the activation energy of coal and delay the development of coal spontaneous combustion (CSC). The findings offer a theoretical basis for exploring the impact of microorganisms on CSC.