1. State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China
2. Liaoning Key Laboratory of Petrochemical Technology and Equipment, Dalian University of Technology, Dalian 116024, P. R. China
3. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 Shanxi, P. R. China