CO2-argon-steam oxy-fuel (CARSOXY) combustion for CCS inert gas atmospheres in gas turbines

Abstract

CO2 emitted from gas turbines in power plants is considered a major contributor to the global environmental damage. Carbon Capture and Storage (CCS) integrated with oxy-fuel (OF) combustion is an advanced and innovative approach that may be used in turbines to reduce these emissions. This method is based on CO2 recycling, however the obstacle to using this recirculation approach in gas turbines is reduction in their performance and reliability. This paper attempts to address the problem in a novel way by investigating theoretically a number of blends that can overcome the performance and reliability issues of pure CO2. These blends, comprising of argon, H2O and CO2, can be used as a working fluid with oxygen and methane as reactants. Additionally, a numerical model for an industrial gas turbine is employed. The aim is to find the optimum blend for complete NOx elimination with a recirculation of products. This study uses 0-D chemical kinetic software (Gaseq), an empirical selection approach with design of experiments and, 1-D chemical kinetic software (CHEMKIN-PRO). Results identify the optimum blend which is numerically assessed in an industrial gas turbine that has been experimentally correlated. The efficiency of this turbine running the selected blend is 1.75–13.93% higher than when running with natural gas/air conditions. This shows the promising use of this blend for a future high efficiency CCS-Oxyfuel approach in gas turbine combustors.