In future work, equilibrium compositions calculated from our equilibrium constant predictions may be used in conjunction with the individual reaction enthalpies obtained in this work to predict both integral and differential overall heat (physical absorption + chemical reaction) of CO 2 absorption in the amine-water system, which is a fundamentally important quantity for solvent selection in the PCC process. For such calculations, isocoulombic reactions have the intrinsic advantage that the ionic activity coefficient contributions to the reaction free energy change cancel for simple models such as the Davies extension of the Debye-Hückel model, which become numerically equivalent to an ideal solution model.