Modeling of solubility characteristics in carbon dioxide-alkanolamine systems using optimization technique

Most of the CO$sb2$-alkanolamine solubility prediction studies in the past were based on the Kent-Eisenberg model (1976), which assumed that the CO$sb2$-alkanolamine systems are ideal (activity and fugacity coefficients of the system taken to be unity). Since the systems are, in fact, highly non-ideal, Kent and Eisenberg suggested that the concentration-based equilibrium constants of the alkanolamine protonation and/or the carbamate reaction should be fitted to the given experimental data.;In the present study, the concept of using multiple apparent constant parameters and sensitivity analysis was developed based on a modified Kent-Eisenberg model. To overcome the weakness of the Kent-Eisenberg model, apparent (non-ideal or real "concentration-based") equilibrium constants were introduced for all the important reactions in the alkanolamine solutions. Since the apparent equilibrium constants are the combined terms of the activity coefficients, the fugacity coefficient, the water activity and the ideal constants, they are realistic constants that would accurately represent the non-idealities of the systems.;In this thesis, the new model was tested with the solubility of CO$sb2$-2-amino-2-methyl-1-propanol (AMP) system. Three apparent equilibrium constants of protonated alkanolamine dissociation, bicarbonate ion formation and physical dissolution of CO$sb2$ were identified to be the most significant parameters in this system. Previously published data was used to determine these three constants utilizing nonlinear and linear least-squares techniques. The predictions from the present model agree well with the 121 experimental data points available in the literature. (Abstract shortened by UMI.).