Absorption-based carbon capture energy penalty reduction for low CO2 content applications: Comparison of performance using different solvents and process configurations on micro gas turbine application

Amine(s)-based post-combustion Carbon Capture (CC) is the most mature technology to retrofit existing Combined Cycle Gas Turbine (CCGT) plants. However, its high energy demand, mainly due to the low CO2 content in flue gases, limits its deployment. Minimizing energy penalty is therefore crucial to enhance the efficiency of low-carbon gas turbines, but limited research has focused on low CO2 applications. To this end, this study evaluates solvent and process selection’s impact on reducing the CC energy penalty in gas turbines, focusing on micro Gas Turbines (mGTs) with Exhaust Gas Recirculation (EGR) to replicate CCGT flue gas properties. Plant performance is assessed through validated Aspen Plus models at a semi-industrial scale. The results showed that replacing 30 wt.% monoethanolamine (MEA) solvent with 10 wt.% of methyldiethanolamine (MDEA)/ 20 wt.% of piperazine (PZ) blend reduces the Specific Reboiler Duty (SRD) by 15.44% and the total cooling load of the CC plant by 16%. However, configurations like Rich Solvent Recycle (RSS) and Rich Solvent Split (RSS) yield only minor SRD reductions (4.7% and 2.5%). While replacing MEA with MDEA/PZ improves mGT electrical (+0.5%) and thermal (+6%) efficiencies, RSR and RSS have a limited impact. These findings provides key insights into optimizing the CC process for CCGTs.