CO2 Capture Cost Reduction: Use of a Multiscale Simulations Strategy for a Multiscale Issue

Carbon Capture and Storage (CCS) is one important option for CO2 mitigation (International Energy Agency, 2009) . Post-combustion capture processes using amines are considered one of the preferred options for CCS. However, the cost of avoided CO2 is very large and must be reduced. The present article aims to show that combining different simulation tools used on different scales makes possible afine analysis of CO2 capture costs and the associatedparameters responsible for these costs on different scales. It is first shown, from a macro-scale techno-economic analysis, that investments represent about one half of the total CO2 cost. Focusing on this cost, a sensitivity analysis, via Aspen calculations performed on a meso-column scale, enables one to identify key mass-transfer parameters that control absorption column design. It is shown that the most important mass-transfer parameter is the interfacial area, the gas and liquid mass transfer coefficients having almost no influence. Finally, from CFD (Computational Fluid Dynamics ) simulations performed both on a large and on a local scale, some insights are given in order to optimize column design, first via the determination of large-scale distributor/packed bed interactions, and second via the determination of local pressure drop or local mass transfer parameters. It is also discussed how simulations should be performed on different scales in a two-way coupling approach in order to ensure fruitful results in the development of new technologies and further in CO2 capture cost reduction.