Effect of microwave-assisted acidification on the microstructure of coal:XRD,^(1)H-NMR, and SEM studies

作     者：He Li Wuche Liu Jiexin Lu Yi Lu Shiliang Shi Zheng Wang Qing Ye Zhenzhen Jia He Li;Wuche Liu;Jiexin Lu;Yi Lu;Shiliang Shi;Zheng Wang;Qing Ye;Zhenzhen Jia

作者机构：School of ResourceEnvironment and Safety EngineeringHunan University of Science and TechnologyXiangtan 411201China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2023年第33卷第7期

页      面：919-926页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：supported by the National Natural Science Foundation of China (Nos. 52274195, 52274196, 51904103, and 52174180) the Science and Technology Innovation Program of Hunan Province (No. 2022RC1178) Hunan Provincial Natural Science Foundation of China (Nos. 2022JJ20024, and 2021JJ30254) Scientific Research Foundation of Hunan Provincial Education Department (No. 21B0465) 

主　　题：Microwave-assisted acidification Microstructure XRD ^(1)H-NMR SEM 

摘      要：Microwave heating contributes to coal fracturing and gas desorption. However, problems of low penetration depth, local overheating and fracture closure exist. Coal demineralisation by acids has advantages in coal unblocking and permeability improvement, while it is difficult for acid to enter ***-asisted acidification may offer an alternative. In this work, XRD,^(1)H-NMR, and SEM were used to evaluate the effect of microwave-assisted acidification on the microstructure of coal. Results show that kaolinite, calcite, and dolomite can be dissolved by acid. After microwave irradiation, the graphitization of microcrystalline structure of carbon improves. Microwave-assisted acidification erodes minerals in coal and enhances the graphitization degree of microcrystalline structure. Compared to individual microwave irradiation or acidification, the pore volume and pore connectivity can be greatly enhanced by microwave-assisted acidification. The NMR permeability of coal increased by 28.05%. This study demonstrates the potential of microwave-assisted acidification for coalbed methane recovery.