Figure shows scatter plots of work equivalent versus productivity with the points coloured by the CO2 LDF constant for values of work equivalent below 2.5 MJ kg -1 . We observe that CO2 LDF constants of 0.003 s -1 and above are requisite to reaching the lowest work equivalent for both the TVSA and S-TVSA processes. This is equal to the value of the CO2 LDF constant of Lewatit® VP OC 1065.