LAUSR

Abstract This paper focuses on identifying the cost limits of two single-stage pressure–vacuum swing adsorption (PVSA) cycles for post-combustion CO 2 capture if the “ideal” zero-cost adsorbent can be discovered. Through an integrated techno-economic optimisation, we simultaneously optimise the adsorbent properties (adsorption isotherms and particle morphology) and process design variables to determine the lowest possible cost of CO 2 avoided (excluding the CO 2 conditioning, transport and storage) for different industrial flue gas CO 2 compositions and flow rates. The CO 2 avoided cost for PVSA ranges from 87.1 to 10.4 € per tonne of CO 2 avoided, corresponding to CO 2 feed compositions of 3.5 mol% to 30 mol %, respectively. The corresponding costs for a monoethanolamine based absorption process, using heat from a natural gas plant, are 76.8 to 54.8 € per tonne of CO 2 avoided, respectively showing that PVSA can be attractive for flue gas streams with high CO 2 compositions. The “ideal” adsorbents needed to attain the lowest possible CO 2 avoided costs have a range of CO 2 affinities with close to zero N 2 adsorption, demonstrating promise for adsorbent discovery and development. The need for simultaneously optimising the particle morphology and the process conditions are emphasised.