1. State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
2. Key Laboratory of Coal Science and Technology, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
3. Shanxi Huaxin Gas Energy Research Institute Co., Ltd., Taiyuan 030032, Shanxi, China