1. State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan030024, Shanxi, P. R. China
2. College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan030024, Shanxi, P. R. China
3. Departments of Chemical and Petroleum Engineering, University of Wyoming, Laramie, Wyoming82071, United States
4. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia30332, United States
5. School of Energy Resources, University of Wyoming, Laramie, Wyoming82071, United States