CO2 solubility modelling in Non-Precipitating aqueous solutions of potassium lysinate

Abstract

Modelling of CO2 solubility in aqueous solutions of potassium lysinate (LysK) is mainly hindered by scarcity of experimental vapor–liquid equilibrium data and lack of chemical equilibrium constants associated to the reaction mechanism for the CO2/LysK/H2O system. Therefore, Kent-Eisenberg (KE) correlation stands out from the literature, being among the most used approaches for the description of the equilibrium CO2 partial pressure at different loadings. In this work, a Kent-Eisenberg-like approach has been developed, enhancing the empirical Kent-Eisenberg with Debye-Hückel activity coefficients in order to guide model calibration with reference to selected experimental data for CO2 solubility in 33.1 and 33.5 %w/w aqueous LysK solution; moreover, the KE edition provides an estimation of the missing equilibrium constants. This information has been embedded in a first thermodynamically sound and predictive Deshmukh-Mather (DM) model (average absolute deviation equal to 7 %) validated against additional experimental data in a wide temperature and concentration range.