A review of semi-empirical equilibrium models for CO2-alkanolamine-H2O solutions and their mixtures at high pressure

The knowledge of vapour-liquid equilibrium (VLE) the carbon dioxide-alkanolamine-water system at high pressure plays a critical role in design natural gas sweetening systems. Semi-empirical thermodynamic models have been widely used to estimate VLE pressure. However, understanding their correlation behaviour is limited. Therefore, this study reviews chronological development and analyse performance two types semi-empirical for pressure-high loadings. effect process parameters first analysed on theoretical basis then modelled with use correction factors, defining systematic contribution different such models. analysis shows that require small corrections good pressure, if constants are well-determined. reports both reliable improved values alkanolamines, where applicable. In addition, combined constant based modified estimating said system, which were previously limited low equilibria loadings only. presents comprehensive review models, highlighting key issues, challenges future recommendations.