文献类型：期刊文献

英文题名：Effect of hydrothermal treatment on the carbon structure of Inner Mongolia lignite

作者：Liu, Peng[1];Zhang, Dexiang[2]

机构：[1]Changzhou Univ, Inst Urban & Rural Min, Natl Local Joint Engn Res Ctr Biomass Refining &, Changzhou 213164, Jiangsu, Peoples R China;[2]East China Univ Sci & Technol, Dept Chem Engn Energy Resources, Shanghai 200237, Peoples R China

年份：2020

卷号：7

期号：3

起止页码：493

外文期刊名：INTERNATIONAL JOURNAL OF COAL SCIENCE & TECHNOLOGY

收录：EI(收录号：20203409084973);WOS:【ESCI(收录号:WOS:000703998400008)】；

基金：This study was funded by National Key Basic Research Development Program of China (973Program, No. 2011CB201304), Natural Science Foundation of China (51906021 and 51703014), National Key R&D Program of China (2018YFC1901203), Research Foundation for Advanced Talents of Jiangsu University (16JDG022) and Changzhou University (ZMF17020034), Natural Science Foundation of Colleges in Jiangsu Province (19KJB480005), Changzhou Applied Basic Research Plan (CJ20190081), and Science and Technology Project of Guangdong Province, PR China (No. 2016A010105017) and (No. 2017B040404009).

语种：英文

外文关键词：Lignite; Hydrothermal treatment; Carbon structure; Solid C-13 nuclear magnetic resonance

摘要：Understanding the structural properties of lignite during hydrothermal treatment would aid in predicting the subsequent behavior of coal during the pyrolysis, liquefaction, and gasification processes. Here, hydrothermal treatment of Inner Mongolia lignite (IM) was carried out in a lab autoclave. The distribution of carbon in the lignite was monitored via solid C-13 nuclear magnetic resonance spectroscopy, and the functional groups of oxygen in lignite were determined by Fourier transform infrared spectroscopy. The curve-fitting method was used to calculate the content of the functional groups quantitatively. The results show that hydrothermal treatment is an effective method for upgrading the lignite. The side chains of the aromatic ring in lignite are altered, while the main macromolecular structure remains nearly the same. The hydrothermal treatment of IM could be divided into three temperature-dependent stages. The first stage (<493 K) is the decomposition reaction of oxygen functional groups, where the O/C ratio decreases from 0.203 in raw IM to 0.185 for the IM treated at 493 K. In the second stage (493-533 K), hydrolysis of functional groups and hydrogen transfer between water and lignite occur. Here, the ratio of methylene to methyl increases from 0.871 in IM-493 to 1.241 for IM-533, and the content of quinone generates from the condensation of free phenol increased. The third stage (>533 K) involves breakage of the covalent bond, and the content of CH4 and CO in the emission gas clearly increase.