Here, we investigate a novel system for CO2 capture from a gas turbine. The aim is to boost the concentration of CO2 in the exhaust of the system by partially recycling the gas. We will also investigae the potential for a radically new cycle involving oxygen firing (with recycled CO2 to keep the temperature down).
Studies of the impact of exhaust gas recycling, including selective CO2 recycling using separation membranes, to enhance exhaust gas CO2 levels, reduce volumetric flow rates and therefore to reduce the size and costs of the capture plant have been carried out during the past five years by the applicants (e.g. GASFACTS, SELECT, Call-1-UKCCSRC4). Our research has demonstrated significant changes to combustion and hot gas path environments, and potential impacts on operability, materials and component lives while maintaining pollutant emissions within limits. CCGT power plants with EGR/CO2-rich strategies, can be "recoded" with a closed supercritical CO2 (s-CO2) cycle with oxy fuel high pressure combustion for improved efficiency and plant flexibility. Furthermore, the S-CO2/oxy-combustion strategy can be an effective solution for the full integration of Power-to-Gas, CCS, and S-CO2 pumping (Enhanced Oil Recovery, water-free shalegas extraction). Availability of detailed reaction schemes is essential to design the high pressure combustor by providing information on the timescale of chemical reactions. However, the use of validated reaction schemes at high pressure is subject to many uncertainties. We will focus on the following tasks: i) assessing the capability of the available reaction scheme for NG combustion at high pressure by collecting available data generated by different investigators using Quantum Mechanic simulation and Boxed Molecular Dynamic simulation (up to 200 bar). ii) evaluating kinetic models for both direct fired oxy-combustion and an indirect fired sCO2 energy system iii) developing a reduced reaction scheme and then integrating with CFD for flow field design. Finally, different cycles will be evaluated and optimised to determine combustor design parameters, cycle layout and efficiency, including optimal start and enhanced operational flexibility.