Comprehensive Thermo-economic Optimization of a Retrofit Amine-based Carbon Capture Process Applied to a Pulverized Coal-fired Power Plant

Carbon dioxide abatement strategies are becoming crucial in the net-zero strategy defined by IEA, especially in those countries where the dependency on fossil fuels and specifically on coal is hard to abate in the short-medium term future. In this work, an in-house model, successfully developed and validated by the authors in UniSim^®, was used to simulate an amine-based carbon capture system, designed to capture 90 % of the carbon dioxide emissions of a 500 MW_e supercritical coal fired power plant. Leveraging the interface between UniSim^® and MATLAB^®, a thermo-economic model has been developed and optimized to minimize energy consumption and the cost associated with the installation and the operation. The optimization is performed for a range of nominal lean CO₂ loading and absorber/stripper stages to investigate the influence of key design variables on the thermo-economic performance of the system. The retrofit case study is presented to demonstrate the usefulness of the proposed design and optimization framework and to provide practical guidelines and conceptual techno-economic insights for the design of a coal-fired power plant with CO₂ capture. The results show that the methodology is capable of capturing the optimal point of techno-economic design of the carbon capture plant with a specific reboiler heat duty of 3.26 MJ/kgCO₂ and a LCOE of 107.5 USD/MWh_e, representing for the latter indicator a 64 % increase compared to the case without capture. The achieved reduction of the power plant carbon intensity (156 gCO₂/kWh_e) comes at the cost of an additional heat requirement that in the retrofit case study triggers a significant energy penalty of the power plant (18 %).

Carbon capture, Coal-fired power plants, MEA solvent, Thermo-economic optimisation, Mitigation technologies

10.1016/j.energy.2026.142422

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