The performance of the PSA cycle is optimised by coupling the PSA process model with the Non-dominated Sorting Genetic Algorithm (NSGA-II). We conduct two separate optimisation stages in this study. The first is an unconstrained maximisation of the CO2 purity and recovery. For this stage, the genetic algorithm is terminated after 70 generations. The second stage is a multi-objective optimisation, whereby we maximise the productivity while simultaneously minimising the energy penalty subject to the two CCS constraints: CO2 purity ≥ 0.9 and CO2 recovery ≥ 0.9. For this stage, the genetic algorithm is terminated after 250 generations. We confirm that 70 and 250 generations for the CO2 purity-recovery and energy-productivity optimisations, respectively, are sufficient to guarantee convergence of the Pareto fronts.