Systematic selection of amine mixtures as post-combustion CO2 capture solvent candidates

A systematic approach is proposed for the preliminary screening of binary amine mixtures as CO2 capture candidates considering several important properties as selection criteria. The approach consists of several decision making stages which account for solvent-solvent and solvent-solvent-CO2 interactions using standard group contribution models as well as equations of state and activity coefficient models for a wide range of molecular structures. A multi-criteria assessment methodology is combined with a systematic uncertainty quantification approach to unveil important trade-offs among several important properties and to propose the mixtures that appear to be promising as CO2 capture candidates. The aim of the proposed approach is to support the identification of few valid amine combinations which may then be evaluated using rigorous prediction models or experiments, while quickly avoiding amine options of poor performance. The proposed method is applied in mixtures resulting from numerous binary combinations of amines which have been previously investigated in their pure aqueous form as CO2 capture solvents. A mixture of 4-diethylamino-2-butanol (DEAB) and 2-amino-1-hexanol (2A1H) appears to be promising among other useful options.