CO2 concentration-based comparison of EMAR and MCFC technologies for carbon capture: Energy and life cycle cost assessments

Carbon capture and storage (CCS) is vital for limiting global temperature rise, particularly to the 1.5°C target. While thermal amine-based CCS technologies are among the most established, they face challenges such as high energy consumption and amine degradation. This has driven interest in alternative electrochemical approaches that promise greater energy efficiency. This study compares the performance of two advanced CCS technologies: molten carbonate fuel cells (MCFCs) and electrochemically mediated amine regeneration (EMAR). Optimized configurations for both systems were developed, and their energy performance and lifecycle costs were evaluated. The EMAR system was modeled using mass and energy balance equations, reaction equilibrium constants, and ionic activity models, and the MCFC system was based on electrochemical principles and Gibbs free energy minimization. Models were validated for accuracy before conducting a comprehensive lifecycle cost analysis and parametric studies. These studies assessed the impact of CO₂ concentration in emission sources and system design parameters on carbon capture work and life cycle costs. At a comparable minimum energy consumption of 72.6 kJ/molCO2 for both systems, MCFC demonstrated lower capture costs (71–85 $/ton) compared to EMAR (90.4–91.2 $/ton). Under a minimum cost scenario of 91 $/ton, MCFC achieved carbon capture work between 12.5–65 kJ/molCO2, whereas EMAR operated consistently within the range of 72–72.6 kJ/molCO2. The results highlight MCFC superior energy efficiency and cost advantages, while EMAR offers operational stability. These findings underline the potential of both technologies for advancing CCS, though their feasibility may vary with fluctuations in electricity and natural gas prices.