Oxy-Fuel Combustion Supercritical CO2 Power Cycle – A Critical Look

Abstract

There has been a significant research and development effort directed at development of power generation cycles with supercritical carbon dioxide (sCO2) as the working fluid. Due to the unique properties of CO2 at pressures and temperatures above its critical point, it is possible to design compact turbomachinery with high efficiency for diverse applications ranging from nuclear power to waste heat recovery. A particular variant of sCO2 power cycles combines the basic semi-closed, recuperated cycle with oxy-fuel combustion to achieve high efficiency with the inherent capability of capturing excess CO2 for subsequent disposal via utilization (e.g., enhanced oil recovery or as an industrial product) or underground sequestration. This feature makes the oxy-fuel combustion (or oxycombustion), sCO2 cycle-based power generation technology a strong competitor with conventional fossil fuel combustion-based systems with pre- or post-combustion carbon capture, e.g., coal-fired thermal power plants and natural gas-fired gas turbine combined cycle power plants. This paper takes a close look at the oxycombustion sCO2 cycle to gauge whether it can be developed into a credible alternative for the latter (since coal-fired power plants are being phased out in developed countries at an increasingly rapid pace).