Commercially available techniques for the removal of 90% of CO 2 from power station flue gas were investigated by H&G for British Coal Corporation. This work was part of British Coal's studies of CO 2 abatement technologies. The two cases examined were based on:- 1. A A gas containing a low concentration of CO 2 produced by a 500 MW e conventional pulverised fuel (PF) power station. 2. B A gas containing a high concentration of CO 2 produced by a novel power station design in which coal is burnt in a mixture of oxygen and recycled flue gas. A screening of commercially proven CO 2 removal processes established that for Case A either aqueous monoethanolamine (MEA) or hot potassium carbonate (HPC) were suitable. For Case B either HPC or gas permeation membranes were identified as suitable. An analysis of operating costs including the impact on plant efficiency, but excluding the cost of oxygen in Case B , revealed that for Case A the use of MEA would be 30% cheaper than the use of HPC;whereas for Case B a 50% operating cost advantage was identified for the use of membranes compared with HPC. Thus MEA and membranes were selected for further evaluation for cases A and B respectively. Capital cost estimates for the CO 2 removal process areas were subsequently derived for the preferred options for the two cases. For a UK greenfield site, the capital costs of the CO 2 removal sections were estimated to be £98 million for Case A. For Case B an estimated £36 million was obtained for purification of CO 2 with a gas permeation membrane. Some major technical constraints for the selected process routes were identified including the detrimental effect on operability of particulate carryover from the FGD and the high levels of SO 2.