A novel IGCC plant with membrane oxygen separation and carbon capture by carbonation-calcinations loop

Environmental degradation due to large emission of pollutants including green house gases from conventional coal based power plants is presently of great concern. On the other hand, existing dependence on the coal based power plants to meet the increasing electricity demand cannot be changed abruptly. Hence developing efficient coal based power plants with low emissions is of great demand. IGCC plants are established technologies for this purpose. However, CO2 capture still causes substantial reduction in efficiency. In this paper, a novel IGCC plant integrating oxygen separation from air by ceramic membrane and post combustion CO2 capture by a twin fluidized bed carbonation-calcinations loop has been proposed. A simulation of this conceptualized plant shows significant increase in efficiency than a comparable IGCC plant with conventional pre-combustion capture. The new IGCC concept reached a net efficiency of 43.2% based on LHV for hard coal. Furthermore, the concept allows CO2 recovery of almost 98% resulting in substantially lower specific CO2 emissions of 22.1 g/kWh. A complete description of the plant and detailed simulation results in comparison with the previous IGCC plant are discussed. Additionally, a short parametric study is performed to demonstrate basic process interaction and further thermodynamic potential. (C) 2011 Elsevier Ltd. All rights reserved.