The solubility of hydrogen sulfide in aqueous N-methyldiethanolamine solutions

Abstract

Abstract:In this work the electrolyte equation of state as developed previously for the system MDEA-H 2 O-CO 2 -CH 4 [Huttenhuis et al. (2008), pp.99-112] was further developed for the system MDEA-H 2 O-H 2 S-CH 4 . With this thermodynamic equilibrium model the total solubility of hydrogen sulfide and the speciation in aqueous solutions of N-methyldiethanolamine can be described quantitatively. The model results were compared to experimental H 2 S solubility data in aqueous MDEA in absence and presence of methane respectively. The application of equation of state models for this kind of acid gas -amine systems is a rather new development in the literature. An accurate description is difficult for this kind of complex systems with significant amount of both molecular and ionic species present in the liquid phase. The Schwarzentruber's modification of the Redlich-Kwong-Soave EOS with a Huron-Vidal mixing rule is used as molecular part of the equation of state and ionic interactions terms are added to account for non-idealities caused by these interactions. With the new developed model a comparison with experimental data as presented was made.

Modeling of H2S, CO2 + H2S, and CH4 + CO2 Solubilities in Aqueous Monoethanolamine and Methyldiethanolamine Solutions

“…Solbraa has used a Schwarzentruber’s modification of the Redlich–Kwong–Soave EoS with a Born term and the Huron–Vidal mixing rules to model CH 4 –CO 2 –MDEA–H 2 O mixtures. The results of the model are close to the experimental data of Addicks et al The same model was used by Huttenhuis et al − Dicko et al studied the effect of methane on the partial pressure and fugacities of acid gases in aqueous MDEA. They found that changes in the partial pressure of methane affect the partial pressure of acid gases.…”

Solubility of Carbon Dioxide and Hydrogen Sulfide in Aqueous N-Methyldiethanolamine Solutions

“…During simulations, it appeared that the model results were not sensitive to the value of the CO 2 −H 2 S interaction parameter. The values for all other parameters used in the E-EOS model were identical to those used for the single-gas systems. ,, …”

“…In this work, an electrolyte equation of state (E-EOS) is used to describe the CO 2 −H 2 S−MDEA−H 2 O−CH 4 system. This model has already been applied to the systems CO 2 −MDEA−H 2 O−CH 4 and H 2 S−MDEA−H 2 O−CH 4 . The reason for the selection of this thermodynamic E-EOS model instead of the commonly used activity-based models (such as NRTL) is that extrapolation to other process conditions, extension to different types of inert components, and vapor−liquid equilibrium (VLE) predictions at high pressure seem to be feasible with the former.…”

Experimental Study of a Hydrophobic Solvent for Natural Gas Sweetening Based on the Solubility and Selectivity for Light Hydrocarbons (CH4, C2H6) and Acid Gases (CO2 and H2S) at 298–353 K

“…The method is described thoroughly by Versteeg and Van Swaaij . The physical absorption of the CO 2 and H 2 S in a given solvent can be described using the N 2 O analogy proposed by Versteeg and Van Swaaij and Huttenhuis et al and given as the following equations: Solubilities of N 2 O and CO 2 in water were taken from the work of Versteeg and Van Swaaij, while solubilities of H 2 S in water were taken from Kohl and Nielsen . A simplified HPS-based gas sweetening process using a gas–liquid absorber was performed in this work to validate the technical feasibility and project the acid removal performance of HPS.…”

“…The method is described thoroughly by Versteeg and Van Swaaij. 16 The physical absorption of the CO 2 and H 2 S in a given solvent can be described using the N 2 O analogy proposed by Versteeg and Van Swaaij 16 and Huttenhuis et al 17 and given as the following equations:…”