Title: Reactivity and spontaneous combustion characteristics of high-sulphur coal during low-temperature oxidation

Authors: Li Ma; Li Zou; Lifeng Ren; Jianli Wang; Weifeng Wang

Addresses: School of Safety Science and Engineering, Xi'an University of Science and Technology, China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China ' School of Safety Science and Engineering, Xi'an University of Science and Technology, China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China ' School of Safety Science and Engineering, Xi'an University of Science and Technology, China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China ' Hancheng Mining Co., Ltd., Jinta East Rd., Hancheng, Shaanxi 715400, China ' School of Safety Science and Engineering, Xi'an University of Science and Technology, China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China

Abstract: This study investigated the spontaneous combustion characteristics and the microscopic reaction mechanism of high-sulphur coal during low-temperature oxidation. Five coal samples with different levels of sulphur content (including 3.13, 4.18, 5.06, 6.28 and 7.00%) were selected and experiments were conducted with a temperature-programmed system and Fourier transform infrared spectroscopy (FTIR). It was shown that the O₂ consumption rate, CO and CO₂ production rates all rose with increased sulphur content, while they gradually fell after the sulphur content exceeded 5.06%. Conversely, when the sulphur content went up, the apparent activation energy dropped and showed a minimum at a sulphur content of 5.06% and was higher thereafter. The key functional groups participating in the oxidation reaction before the critical temperature was reached were methyl and carbonyl. Furthermore, the key functional groups were alkyl ether and carbonyl before and after the crack temperature, respectively. [Received: July 6, 2018; Accepted: September 24, 2018]

Keywords: coal spontaneous combustion; low-temperature oxidation; sulphur in coal; apparent activation energy; characteristic temperature; key functional groups.

DOI: 10.1504/IJOGCT.2019.100230

International Journal of Oil, Gas and Coal Technology, 2019 Vol.21 No.3, pp.375 - 389

Received: 06 Jul 2018
Accepted: 24 Sep 2018
Published online: 19 Jun 2019 *

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