High pressure measurement and thermodynamic modelling of the solubility of carbon dioxide in N-methyldiethanolamine and 1-butyl-3-methylimidazolium acetate mixture

For thermodynamic modelling, a new equation of state (PR-TS EoS) is extended by combining the Peng-Robinson (PR) equation of state as a cubic term for non-specific energy contribution and the Two-State Association Model (TSAM) for association energy contribution based on the frame of the cubic plus equation of state. Furthermore, the PR-TS EoS is applied to correlate the new experimental data of this work. To model the ternary (CO2 + MDEA + [bmim][acetate]) system, the parameters of the PR-TS EoS are first adjusted for the pure components. Subsequently, the solubility of CO2 in pure [bmim][acetate] is correlated so that the binary molecular interaction parameters for this binary sub system are optimised. Finally, the equilibrium solubility of CO2 in ternary mixture of {MDEA + [bmim][acetate]} correlates with the per cent average absolute deviation (AAD%) of 11.78 between the calculated and experimental partial pressure of CO2.