Yang Lin, Zhang Yongfeng, Hao Zhifei, Zhang Junying
College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China.
Inner Mongolia Key Laboratory of Efficient Cyclic Utilization of Coal-Based Solid Waste, Hohhot, 010051, China.
Heliyon. 2023 Jul 16;9(8):e18352. doi: 10.1016/j.heliyon.2023.e18352. eCollection 2023 Aug.
The chemical structure of lignite plays a fundamental role in microbial degradation, which can be altered to increase gas production. In this study, the structural changes in lignite were analyzed by conducting pretreatment and biomethane gas production experiments using crushing and ball milling processes, respectively. The results revealed that different particle size ranges of lignite considerably influence gas production. The maximum methane yield under both treatments corresponded to a particle size range of 400-500 mesh. The gas production after ball milling was higher than that after crushing, irrespective of particle size. Compared with lignite subjected to crushing, that subjected to ball milling exhibited more oxygen-containing functional groups, less coalification, more disordered structures, and small aromatic ring structures, demonstrating more unstable properties, which are typically favorable to microbial flora for the utilization and degradation of lignite. Additionally, a symbiotic microbial community comprising multiple species was established during the microbial degradation of lignite into biogas. This study provides new insights and a strong scientific foundation for further research on microbial lignite methanation.
褐煤的化学结构在微生物降解中起着基础性作用，其结构可被改变以提高气体产量。在本研究中，分别通过破碎和球磨工艺进行预处理及生物甲烷产气实验，分析了褐煤的结构变化。结果表明，不同粒径范围的褐煤对产气有显著影响。两种处理方式下的最大甲烷产量均对应于400 - 500目的粒径范围。无论粒径大小，球磨后的产气均高于破碎后的产气。与经破碎处理的褐煤相比，经球磨处理的褐煤具有更多的含氧官能团、更低的煤化程度、更无序的结构以及更小的芳香环结构，表明其性质更不稳定，这通常有利于微生物菌群对褐煤的利用和降解。此外，在褐煤微生物降解为沼气的过程中建立了一个包含多个物种的共生微生物群落。本研究为进一步开展微生物褐煤甲烷化研究提供了新的见解和坚实的科学基础。
