Integration and Evaluation of Power Generation System with Extract Residue of Coal Liquefaction Residue

Abstract

Extract residue of coal liquefaction residue (ERCLR) is a solid mixture of high carbon, high ash, high sulfur, and complex composition, mainly including unconverted coal, inorganic minerals, and coal liquefaction catalyst. The effective use of ERCLR, which has high utilization value based on high hydrogen-to-carbon ratio, not only improves the thermal efficiency and economy of coal liquefaction process, but also reduces the emissions of pollutants. The energy efficiency analysis, environmental impact, and economic analysis of three power generation systems were calculated and analyzed by Aspen Plus. The three power generation systems are ERCLR gasification combined cycle power generation system, ERCLR combustion power generation system, and ERCLR pyrolysis combustion power generation system. The results show that the energy efficiency of ERCLR gasification combined cycle power generation system is 47.5%, which is better than that of ERCLR combustion power generation system (43%) and ERCLR pyrolysis combustion power generation system (45.3%). The flue gas emission of ERCLR gasification combined cycle power generation system has lower impact on environment than that of the other two systems. ERCLR gasification combined cycle power generation system provides a lower cost of electricity (0.44 CNY/kWh), compared with ERCLR combustion power generation system (0.48 CNY/kWh) and ERCLR pyrolysis combustion power generation system (0.69 CNY/kWh). Therefore, ERCLR gasification combined cycle power generation system has significant advantages over the other two utilization approaches. For the recovery and utilization of ERCLR, ERCLR gasification combined cycle can be given priority to power generation.

Keywords

• extract residue of coal liquefaction residue
• power generation
• energy efficiency
• environmental impact
• power generation cost