Optimization of CO₂ Capture from Natural Gas Combined Cycle with Hydrogen-Assisted Exhaust Gas Recirculation

¹ SINTEF Energy Research, Trondheim, Norway
² University of Florence, Florence, Italy
³ Baker Hughes, Florence, Italy

^* Corresponding author: mario.ditaranto@sintef.no

Abstract

CO₂ capture and storage (CCS) is crucial for reducing emissions in areas with limited renewable energy or to balance their intermittent nature. CCS, however, reduces the efficiency of gas turbine combined cycles due to the high air-to-fuel ratio, resulting in low CO₂ concentration in exhaust gases. Exhaust Gas Recirculation (EGR) can increase CO₂ levels but is limited to about 35% due to combustion stability issues. The EU project TRANSITION explores using hydrogen to pilot burners, allowing higher EGR rates without compromising combustion stability. Experimental data on emissions and Lean Blowout resistance were used to model the impact of hydrogen-assisted EGR on CO₂ capture and overall efficiency. Results indicate that higher EGR rates reduce CO₂ capture energy requirements and equipment sizes, with minimal additional energy costs for EGR systems. The study aims to optimize hydrogen use for maximum efficiency gains while considering costs, safety, and auxiliary energy use. Additionally, the integration of hydrogen-assisted EGR shows promise in enhancing the overall performance of gas turbines, making them viable for lowcarbon power generation. This approach could significantly contribute to the energy transition by enabling more efficient and stable CCS in gas turbine systems.