Thermodynamic Performance of IGCC with Oxy-Combustion CO2 Capture

This paper discusses the relevant thermodynamic aspects of IGCC plants with CO2 capture, mainly focusing on oxy-combustion techniques. The following plant configurations were considered here, all based on a dry-feed oxygen-blown entrained-flow gasifier with syngas quench (Shell type) and a FB class gas turbine: (i) two reference cases, one without CO2 cap-ture and one with ‘conventional’ pre-combustion capture, (ii) three oxy-combustion cases, the first one with today’s technology and the other two with advanced technology, including CO2/SO2 co-sequestration or, alternatively, Hot Gas Desulfurization. It is concluded that oxy-combustion techniques in IGCC cycles may deserve some attention in the near future, because they have the potential of achieving better thermodynamic and en-vironmental performance, in comparison with more conventional capture concepts: in the best case, 45% net efficiency and near-zero emissions were predicted. However, some tech-nological challenges are an obstacle to their development, especially as far as the re-design of the gas turbine is concerned.