From MEA to demixing solvents and future steps, a roadmap for lowering the cost of post-combustion carbon capture

Carbon Capture and Storage is one of the main option for CO2 mitigation [1]. Post-combustion capture processes using amines are considered as one of the preferred options for CCS; however, the cost of avoided CO2 is very large and must be significantly reduced [2]. Many works are presently dealing with identifying new solvents, with a particular focus on the energy consumption needed at regeneration step, the latter representing most of the energy penalty of solvent based post-combustion capture processes. In the present article, it is shown from a macro-scale technico-economic analysis, that, for the reference MEA process, reboiler energy consumption is indeed the main target to reduce. A detailed sensitivity analysis is performed to clearly identify and further quantify the relative impact of each parameter (thermodynamics properties, kinetics, and corrosion). Using that cost analysis, the present article shows the methodology used to develop new post-combustion processes, with a particular focus on the main contributions to CO2 costs. Following this methodology, IFP Energies nouvelles developed the new DMX™ process, based on the use of demixing solvents. This process is briefly described and is compared with other original processes based on phase change systems known as promising solutions for lowering CO2 capture costs. Some insights are also given about technologies (G/L contactors and heat exchangers) for further reduction of capital costs.