Investigation on oxy-fuel biomass integrated gasification combined cycle system with flue gas as gasifying agent

Abstract

A biomass integrated gasification combined cycle with oxy-fuel combustion technology is established to realize negative CO2 emissions in power plants. CO2 and H2O from flue gas are adopted as gasifying agents in the proposed system. The effects of gas turbine pressure ratio and inlet temperature with increasing CO2/C on the system performance are studied using Aspen Plus. The results show that as CO2/C increases, the concentration of CO in the syngas first increases and subsequently decreases. The concentration of H2 and the lower heating value of syngas decrease monotonously as CO2/C increases. The system efficiency increases when the CO2/C value, gas turbine pressure ratio, and gas turbine inlet temperature increase, and the influence of the inlet temperature is more significant than that of pressure ratio. When CO2/C, gas turbine pressure ratio, and inlet temperature are 1.0, 20, and 1150 °C, respectively, the energy efficiency reaches 29.1%, and the corresponding exergy efficiency and net power output are 28.4% and 116 MW. Levelized cost of electricity is estimated to be 0.17 $/kWh in the system. The performance results obtained in this study can provide theoretical support for the application of biomass integrated gasification combined cycle with oxy-fuel combustion technology.