Solubility Of Hydrogen Sulfide In Aqueous Alkanolamine Solutions: Experimental Work And Modeling

Aqueous amine solutions are widely used in the industry for acid gas removal. Although the acid gases removal is a well known industrial operation that has been in use over70years; it has been found that the acid gases solubility data reported in literature by different investigators are inconsistent.In order to treat natural gas or refinery process streams, an accurate knowledge of acid gases solubility data such as Hydrogen Sulfide in aqueous amine solutions is required. In this work, new equilibrium measurements on5.6wt%MEA,8.5wt%MEA,11.6wt%MEA,26.3wt%MDEA,36.3wt%MDEA,46.3wt%MDEA,26.3wt%MDEA+5.6wt%MEA, and36.3wt%MDEA+8.5wt%MEA aqueous solutions with H2S have been produced. The experimental Hydrogen Sulfide partial pressure and temperature were varied from0.358to49.491kPa and from298.15to333.15K respectively while the system total pressure was kept around atmospheric pressure.All the systems considered in this work consist of a two phase vapor-liquid multicomponent systems. Gases were supplied to the Stirred Equilibrium Cell which was operated under the Static Mode. A Vapor-Liquid Equilibrium was established in a Stirred Equilibrium Cell surrounded by a glass vessel jacket through which circulates heated water from the water bath. The equilibrium composition of both liquid and vapor phases was determined by Iodometric Titration.A thermodynamic model is used to predict the VLE composition. Liquid phase non-idealities are accounted by the electrolyte-NRTL equation treating both long-range electrostatic interactions and short-range binary interactions between liquid phase species whereas vapor phase non-idealities are accounted by the Redlich-Kwong-Soave Equation of State. The predicted H2S partial pressures have been found to be in good agreement with experimental data based on the fact that for most of solubility data presented in this work the deviation error is less than5%.