Our results show that within the range studied (i.e., the design space of amine-functionalised adsorbents), the optimal adsorbent for either a TVSA or an S-TVSA process should have the highest possible thermal conductivity and density. Meanwhile, the CO2 LDF constant should be as high as possible up to a value of 0.01 s -1 (after which there is no improvement in process performance).