Simulation of the Effects of Turbine Exhaust Recirculation on the Composition of Flue Gas for A CO2 Capture Unit

Abstract

The main objective of this paper is to study the effects of Flue Gas Recirculation (FGR) ratio and Excess Air (EA) in a natural gas-fired turbine for an effective CO 2 absorption by amines. To achieve this goal, the flue gas should contain at least 10% (mol.) of CO 2 . Moreover, in order to avoid technical problems related to the oxidative degradation of amines, the flue gas should also contain less than 5% (mol.) of O 2 . The simulation results indicate that, for a gas turbine that limits the temperature of the exhaust gas leaving the combustor at 1100°C, an excess air (EA) of 200% and a Flue Gas Recirculation (FGR) ratio of 0.65 are needed to fit the requirements of an effective absorption process by amines. For a turbine that allows temperatures as high as 1500°C, the operating parameters (EA=100% and FGR ratio of 0.4) will be selected.