Preliminary study on macromolecular structure characteristics of Shenhua long flame coal

By using ASE 350 (Accelerated Solvent Extraction) Shenhua long flame coal was extracted with mixed solvent of carbon disulfide/N-methyl pyrrolidone (CS₂/NMP) under high temperature and high pressure, and the extraction rate was about 25%. The extracted residue was degraded by ruthenium ion catalytic oxidation (RICO), then the products were examined with IC and GC/MS, which depends on thermal auxiliary-methyl esterification of tetramethyl ammonium hydroxide (TMAH, 25% methanol solution). The results show that the macromolecular structure of Shenhua coal contains alkyl side chains at a length of C_2~28 and alkyl bridge between aromatic rings at a length of C_2~22. The aromatic condensation level is relatively low (most are conjugated structure of 2~4 benzene rings). And there are many ether linked aromatic structures, oxygen groups like hydroxyl (-OH), carbonyl (C=O), methoxy (-OCH₃), and heteroatom compounds with sulfur and nitrogen.