Impact of the Choice of Entrained-flow Bed Gasification Technology on the Energy Efficiency of IGCC Systems

Gasifier is one of the critical devices in an integrated gasification combined cycle(IGCC) power plant,and the selection of gasifiers has significant impact on the overall efficiency of the whole system.In this study,four different IGCC configurations,employing Shell gasifier,GE gasifier with quench,GE gasifier with heat recovering,and MHI air-blown gasifier,were designed and simulated by GT Pro software respectively.Based on the obtained performance parameters through simulation,both of the efficiency variations of IGCC system when employing various entrained-flow gasification technologies and the inherent mechanisms causing these changes were analyzed.Results show that the energy conversion and distribution of the whole system depend heavily on the feedstock characteristics,choosing of oxidants and methods of syngas sensible heat recovery.In the IGCC system employing Shell gasifier,most of the energy in coal is converted to the chemical energy of syngas,which can contribute to a high overall efficiency,whereas in the systems employing GE gasifier with heat recovery and MHI air-blown gasifier,a larger portion of energy in coal is converted to the sensible heat of syngas,which could be utilized in the following processes.