A method for thermodynamic modeling of H2S solubility using PC-SAFT equation of state based on a ternary solution of water, methyldiethanolamine and hydrogen sulfide.

In this research, in order to determine the solubility of hydrogen sulfide in the aqueous solution of normal methyldiethanolamine, the PC-SAFT equation of state is used. The main focus of the paper is to provide a method for calculating the association term in this equation of state, so that the simplistic assumptions that Huang and Radosz and Najafloo considered based on the type and number of sites on each molecule are avoided, and concentrations are calculated more accurately. Also, by using the parameters in the articles and parameters set in this work, a prediction of the equilibrium solubility of hydrogen sulfide has been carried out for a temperature range of 298 to 413 K and a pressure range of 0.0013 to 5840 KPa. The average percentage of the absolute value of the relative error (AAD%) is 0.000102%. • H 2 S absorption by aqueous Methyl Diethanolamine solution is modeled. • The electrolyte PC-SAFT equation of state has been used for modeling. • For showing the predictability of the PC-SAFT EoS, all of the binary interaction parameters assume zero values. [ABSTRACT FROM AUTHOR]