Title: Sequential thermal dissolution and oxidative depolymerisation of Cheji coal

Authors: Wen-Han Wei; Xiang Bai; Xing Fan; Zhen-Yu Gao; Ran-Ran Hou; Guo-Ming Zhao; Qing Liu; Hai-Feng Zhou; Peng Liang

Addresses: College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' Key Laboratory of Chemistry and Chemical Engineering on Heavy Carbon Resources of Yili Kazakh Autonomous Prefecture, Yili Normal University, Yining, Xinjiang 835000, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China; Key Laboratory of Chemistry and Chemical Engineering on Heavy Carbon Resources of Yili Kazakh Autonomous Prefecture, Yili Normal University, Yining, Xinjiang 835000, China; State Key Laboratory of Coal Mining and Clean Utilization, Beijing 100013, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China ' College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China

Abstract: Organic matter in soft coal (SC) and hard coal (HC) from the same mine was extracted by sequential thermal dissolution (TD) followed by oxidative depolymerisation (OD) to obtain soluble components, which were studied using both gas chromatography/mass spectrometry (GC/MS) and Orbitrap-MS to acquire detailed molecular structure information. Toluene (TOL), tetrahydrofuran (THF), and methanol (ME) were the three solvents used in sequential TD. TOL relaxes the macromolecular structure in coals and exhibits a good solubilisation effect on arenes, THF further destroys non-covalent bonds through swelling, and ME weakens hydrogen bonds among macromolecules and attacks the weak -C-O- bridged bonds. With a higher coalification degree, soluble components from HC show more aromatised structure compared to SC. After the OD treatment, aromatic compounds with a higher degree of condensation were detected in the OD products, and HC contains more fused aromatic rings. [Received: 13 March 2023; Accepted: 28 August 2023]

Keywords: sequential thermal dissolution; oxidative depolymerisation; Orbitrap-MS; coal.

DOI: 10.1504/IJOGCT.2024.136543

International Journal of Oil, Gas and Coal Technology, 2024 Vol.35 No.2, pp.136 - 158

Received: 11 Mar 2023
Accepted: 28 Aug 2023
Published online: 06 Feb 2024 *

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