Solubility of CO2 in 3-amino-1-propanol and in N-methyldiethanolamine aqueous solutions: Experimental investigation and correlation using the CPA equation of state

Abstract

The solubility of CO2 in 1.3M and 2M aqueous N-methyldiethanolamine (MDEA) and 3-amino-1-propanol (MPA) solutions was experimentally measured at 298, 313, 323 and 333 K, using a pressure decay method. Since only limited experimental data exist in literature for MPA aqueous systems, the results of this study were compared with literature data mainly for 2M MDEA solutions, showing satisfactory agreement. The obtained new experimental data were used to parameterize the Cubic-plus-Association (CPA) equation of state using a pseudo chemical reaction approach, i.e. to account for chemical interactions as very strong specific intermolecular interactions, which is a crude approximation, but is necessary for applying equation of state models. It was found that the model satisfactorily describes the experimental data using six or four binary parameters for the CO2-MPA or CO2-MDEA interactions, respectively, which, however, are less than the number of adjustable parameters in similar literature models.