为提高褐煤转化生物甲烷的效率，探讨废弃油脂与褐煤混合发酵的产气效果，采用NMR碳谱、三维荧光及宏转录组学分析转化效率变化的的内在机理，研究结果表明，废弃油脂的添加促进褐煤的累计甲烷产量增加了3.89倍，单位甲烷产量达到31.2 mL。褐煤中脂肪族碳相对含量降低11.4%，类富里酸酚羟基、酮羰基、羰基等基团含量增加明显。同时微生物菌群高峰期时活性产甲烷古菌例如Methanothrix, Methanoculleus占比增长50%以上。糖苷水解酶、脂肪酰辅酶A脱氢酶等与碳水化合物及脂肪酸降解相关的酶丰度增加明显。废弃油脂添加使乙酸及CO₂转化甲烷途径分别占比59.2%、40.4%，甲酰甲烷呋喃脱氢酶以及乙酸激酶等功能性酶也得到提升，促进了生物甲烷的转化。褐煤中脂碳率降低表明了在厌氧发酵中微生物菌群更易与褐煤中碳骨架大分子结构中脂甲基碳、芳香甲基碳、亚甲基及甲氧基等发生生物化学反应转化甲烷。高峰期厌氧发酵液相中生物可降解有机分子含量增加，其来源于微生物作用在褐煤有机质中致使微生物发生生物化学反应产生酚羟基、酮羰基等易于合成甲烷的小分子物质。废弃油脂添加可显著改变微生物群落组成，使其基因功能表达改善，促进甲烷的生成。研究结果为提高褐煤的生物气化率和废弃油脂清洁转化提供了参考。

In order to improve the conversion efficiency of lignite to biomethane, the gas production effect of mixed fermentation of waste oil and lignite was discussed in this paper. NMR carbon spectroscopy, three-dimensional fluorescence and macro transcriptomics were used to analyze the internal mechanism of transformation efficiency changes. The study showed that the addition of waste oil increased the cumulative methane yield of lignite by 3.89 times, and the unit methane yield reached 31.2 mL. The percentage of aliphatic carbon in lignite decreased by 11.4%, and the content of fulvic acid like phenol hydroxyl, ketone carbonyl, carbonyl and other groups increased significantly. At the same time, the proportion of active methanogenic archaea such as Metanothrix and Metanoculleus increased by more than 50% at the peak of microbial flora. Glycoside hydrolase, fatty acyl coenzyme A dehydrogenase and other enzymes related to carbohydrate and fatty acid degradation increased significantly. With the addition of waste oil, the conversion of acetic acid and CO₂ to methane accounted for 59.2% and 40.4%, respectively. Functional enzymes such as formylmethane furan dehydrogenase and acetic acid kinase were also improved, promoting the conversion of biomethane. The addition of waste oil can significantly promote the production of biomethane from lignite, which provides a practical solution to the problem of low gas production from single lignite anaerobic fermentation. The reduction of fat carbon rate in lignite indicates that microbial flora is more likely to react with aliphatic methyl carbon, aromatic methyl carbon, methylene and methoxy in the carbon skeleton macromolecular structure of lignite in anaerobic fermentation to convert methane. The analysis results of liquid components show that the content of biodegradable organic molecules increases, which comes from the function group shedding of lignite due to the action of microorganisms and the biochemical reaction of microorganisms. The addition of waste oil can significantly change the composition of microbial community, improve its gene function expression, and promote the generation of methane.