1. School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
2. State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
3. Biomass and Plasma Technologies, Renewable Energy and Green Technology, TNB Research Sdn. Bhd., Research Institution Area, Kajang 43000, Selangor, Malaysia