Comparative analysis of four gas-fired, carbon capture-enabled power plant layouts

Emission of carbon dioxide from fossil fuel-fired thermal power plants is a major concern for energy providers all around the world. In this context, carbon capture from thermal power plants and the energy penalty incurred in the process are important issues. The present work reports on a detailed analysis of gas-fired power plant layouts with in-built carbon capture, i.e. the flue gas from these power plants contains mainly carbon dioxide and water vapour. Four layouts, two of which are based on pressurized oxyfuel combustion and two on chemical looping combustion (CLC), have been considered. Based on detailed mass balance, energy and thermodynamic analyses of the power plant layouts, the net efficiencies for each plant have been computed. After accounting for thermodynamic irreversibilities and CO2 compression to 110 bar, these have been found to vary between 31 and 52 % for the four plants. Despite the technological maturity of oxyfuel combustion, it is concluded that CLC-based plants would be future-ready in the sense that they can readily accommodate CCS with only 2 % loss in overall thermal efficiency for CO2 capture.