Representation of CO2 and H2S absorption by aqueous solutions of diethanolamine using an electrolyte equation of state

The electrolyte equation of state published in 1993 by Furst and Renon (AIC hE J. 1993, 39, 335) has been applied to the representation of CO2 and H2S solubility in diethaloamine (DEA) aqueous solutions. This equation of state extends the classical Redlich-Kwong-Soave equation of state associated wit h a Wong-Sandler mixing rule to the case of systems containing ions. The st udy of binary systems allowed us to determine the parameters of the nonelec trolyte part of the equation of state. The ionic parameters have been fitte d from experimental solubility data covering a wide range of experimental c onditions (temperature range, 25-100 degrees C; amine concentration, from 0 .5 to 3.5 M; loadings up to 2.34 mol(CO2)/mol(amine)). With the assumption used in previous applications of our model to various electrolyte systems, the adjusted ionic parameters are interaction ones involving protonated ami ne and anions as well as molecular compounds. The resulting model represent s experimental data with deviations consistent with the experimental ones a nd dose to the deviations obtained in previous studies.