(250e) Insight into Coal Structure Based on Benzene Carboxylic Acids from the Coal Via Oxidation

Fan Yang¹, Yucui Hou², Muge Niu¹, Shuhang Ren¹, Weize Wu^1,*

¹State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China

²Department of Chemistry, Taiyuan Normal University, Taiyuan 030031, China

Coal structures, the basis of its applications, have been widely studied. Benzene carboxylic acids (BCAs, 12 types) can be generated from different aromatic clusters of coal via oxidation, and it has been found the 12 BCAs have different yield distributions for different coals. The results suggest that there is a certain relationship between BCAs and coal structure that provides a favorable basis for us to study the coal structures. In this work, based on the BCAs distributions and ¹³C-NMR analyses, we investigated the structure characters of coal with different ranks. The results indicate that with the increase of coal rank, the yield of BCAs increase, and the structures of coal becomes more and more difficult to be degraded. There are great differences in the yield distributions of BCAs with the increase of coal rank, and more and more BCAs with a small number of carboxyl are obtained in high rank coal. Single-ring aromatic clusters and double-ring aromatic clusters are mainly aromatic structures in low rank coal. With an increase in the process of coalification, the aromatic clusters increase in size and the degree of condensed of aromatic rings also increases. When the carbon content of coal was approximate 87 %, the structure of coal had a mutation. At last, we proposed a structural model of Huolinhe lignite based on the yield distribution of BCAs. The work provides a new way to study the coal structures and construct the structural model of coal.

The project is financially supported by the National Natural Science Foundation of China (No. 21676019 and 21076138).

Keywords: Coal structure; Benzene carboxylic acid; Oxidation; ¹³C-NMR