1. State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, Institute of New Energy, China University of Petroleum (East China), Qingdao 266580, P. R. China
2. Sinopec Qingdao Refining & Chemical CO., LTD, Qingdao 266500, P. R. China
3. Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, U.K.
4. National Engineering Research Center of Coal Gasification and Coal-Based Advanced Materials, ShanDong Energy Group CO., LTD, Jinan 250101, P. R. China