Study on the relationship between pyrolysis volatile products and structure of Shengli lignite using TG-FTIR-GC/MS

The composition and structural characteristics of Shengli lignite were characterized by ultimate analysis, 13C-NMR, and FTIR. Pyrolysis volatiles products of lignite were studied by TG-FTIR-GC/MS. Solid 13C-NMR analysis showed that the most abundant in Shengli lignite skeleton structure was aromatic carbon, followed by aliphatic carbon, and some carbonyl carbon. TG-FTIR-GC/MS analysis indicated that the main components of the small molecular gas released by Shengli lignite were CO2, CO, CH4, light arenes, etc., mainly from the carboxyl, carbonyl, aliphatic chains and aromatic structure in the lignite. Normalization method was used to describe the distribution of volatiles products. The release temperature of aliphatic, aromatic, phenolic and naphthalene substances is concentrated around 450–600 °C. The relative content of CO released at 540 °C is the highest, mainly from the pyrolysis of phenol. And the initial release temperature of CO is about 300 °C which is higher than that of CO2 and lower than that of CH4.