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

Abstract

In this work, 72 new experimental solubility data points for H2S and CO2 mixtures in aqueous N-methyldiethanol amine (MDEA) solutions at different methane partial pressures (up to 69 bara) are presented. They are correlated using an electrolyte equation of state (E-EOS) thermodynamic model. This model has already been used to estimate the CO2 solubility in aqueous MDEA ( Huttenhuis Fluid Phase Equilib.200826499112) and the H2S solubility in aqueous MDEA ( Huttenhuis Int. J. Oil, Gas Coal Technol.20081399424). Here, the model is further extended to predict the behavior of CO2 and H2S when they are present simultaneously in aqueous MDEA. The application of an equation of state is a new development for this type of system, i.e., of acid-gas−amine systems. The molecular interactions are described by Schwarzentruber et al.’s modification of the Redlich−Kwong−Soave equation of state, with terms added to account for ionic interactions in the liquid phase. The model is used to describe acid-gas solubility data for the CO2−H2S−MDEA−H2O system reported in the open literature and experimental data reported here for the CO2−H2S−MDEA−H2O−CH4 system.

Vapor–Liquid Equilibria of H2S in Aqueous Mixtures of N-Methyldiethanolamine + Piperazine + Sulfolane

“…However, there are no data on the solubility of H 2 S in MDEA + PZ + SFL mixed solvent. In recent years, some H 2 S equilibrium solubility measurements in alkanolamine solutions have been reported in three categories of MDEA, MDEA-based, ,− and non-MDEA-based ,,,− solutions in aqueous and hybrid context with and without inert gas makeup. ,,,− The corresponding reports, together with the temperature and pressure ranges, are shown in Table .…”

Modeling CO2, H2S, COS, and CH3SH Simultaneous Removal Using Aqueous Sulfolane–MDEA Solution

“…With the development of society, natural gas is increasingly used in industry and daily life due to its economic and environmental advantages [1][2][3]. Since mined natural gas contains acid components (CO 2 and H 2 S) and organic sulfur (COS and CH 3 SH), it needs further treatment before it can be used [4][5][6][7]. Conventional gas processing includes distillation, adsorption, membrane separation, and absorption [8].…”

Thermodynamic modelling of acid gas removal from natural gas using the Extended UNIQUAC model

“…Natural gas is usually contaminated with acid gases (CO2 and H2S). 1 Natural gas sweetening is carried out in order to remove these gases.…”

“…2 Stripping acid gases from natural gas is commonly done by use of aqueous alkanolamines in an absorber-desorber system. 1 In natural gas treatment process, the typical absorber pressure is around 5 to 10 MPa, but the stripper pressure is between 0.1 and 0.3 MPa. In the absorber, mixtures of acid gashydrocarbons, mainly methane, are contacted counter currently with aqueous amines while in the stripper, mixtures of acid gas-amine-water are present as methane and other hydrocarbons are already separated.…”