Toward Nonaqueous Alkanolamine-Based Carbon Capture Systems: Parameterizing Amines, Secondary Alcohols, and Carbon Dioxide-Containing Systems in s-SAFT-γ Mie

Replacement of aqueous alkanolamine-based carbon capture fluids with nonaqueous alternatives may be a promising route to reduce the energy requirements of current postcombustion carbon capture processes. In line with this, the s-SAFT-γ Mie predictive group contribution Equation of State is developed toward a description of the thermodynamic properties of nonaqueous alkanolamine-based carbon capture systems in this work. A consistent and systematic methodology is used to develop s-SAFT-γ Mie group interaction parameters required for modeling these systems. This entails extending the model to the primary amine (CH2NH2/NH2) and secondary alcohol (CHOH) groups, as well as their interactions with the n-alkane (CH2 and CH3) and primary alcohol (CH2OH/OH) groups. Parameters were also developed for the interactions of CO2 with the n-alkane, primary alcohol, and secondary alcohol groups, respectively. The model, with its active parameter sets, generally provides a robust description of the phase equilibria of the systems considered. This renders the developed parameters suitable for expanding the model to ternary-component alkanolamine-based nonaqueous carbon capture systems in further work.