Solubility of carbon dioxide in aqueous solution of monoethanolamine or 2-amino-2-methyl-1-propanol: Experimental measurements and modelling

Despite the importance of the accurate measurement of vapour–liquid equilibria (VLE) data, the reported values, even for well-studied systems such as MEA–H2O–CO2, are scattered. This work centres on the development of an experimental method to measure accurately the VLE of various aqueous amine systems. A static-analytic type of VLE apparatus has been constructed and employed to measure the VLE of CO2 in aqueous monoethanolamine and 2-amino-2-methyl-1-propanol. Gas chromatography was used to analyse the liquid phase compositions. The setup has been validated against literature data for 30 mass% MEA (monoethanolamine) at T = 313 and 393 K and was shown to be capable of generating reliable and repeatable data. New measurements for 30 mass% aqueous AMP (2-amino-2-methyl-1-propanol) solutions are also presented at temperatures between 313 and 393 K and a total pressure range of 23–983 kPa. A quasi-chemical model has been employed to interpret the experimental data for the MEA–H2O–CO2 and AMP–H2O–CO2 systems. The average absolute deviation (ΔAAD) between model prediction and experimental data is within 7%.

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► A new static-analytic apparatus has been constructed which is capable of generating reliable and repeatable VLE results.
► New VLE data for MEA–H2O–CO2 system at T = 313 and 393 K were reported.
► Experiments were conducted to fill the gap of existing VLE data for AMP–H2O–CO2 systems from T = 313–393 K.
► A quasi-chemical model was used to satisfactorily correlate experimental data for MEA–H2O–CO2 and AMP–H2O–CO2 systems.
► Speciation results from the model for MEA–H2O–CO2 and AMP–H2O–CO2 are presented and compared with experimental measurements from other studies.