Modelling of equilibrium solubility of CO₂ and H₂S in aqueous diglycolamine (DGA) solutions

Abstract

Information on acid gas solubility in solvents utilized is needed for the design of gas plants. A mathematical model for the prediction of equilibrium solubility of COz and H2S in aqueous 2-amino-2-(ethoxy)ethanol (DGA) solutions is presented. The equilibrium constants, K , and Kz. representing a simple proton transfer reaction and the carbamate formation reaction, respectively, were found to be functions of temperature and free acid gas concentration. In addition, K?, was affected by DGA concentration as well. Model predictions agree favourably with experimental data.Des donnkes sur la solubilitk des gaz acides dans les solvants sont nkcessaires pour la conception des usines gaz. On prksente un modde mathkmatique pour la prkdiction de la solubilitk d'kquilibre du COz et du H, dans des solutions aqueuses de 2-amino-2(kthoxy)kthanol (DGA). On a trouvk que les constantes d'kquilibre, K , et K 2 , reprksentant une rkaction de transfert de protons simples et une rkaction de formation de carbamate, respectivement, ktaient des fonctions de la tempkrature et de la concentration de gaz acide libre. De plus, la concentration de DGA a influe sur K 2 . Les prkdictions du modttle concordent favorablement avec les donnkes expCrimentales.Keywords: CO, solubility in diglycolamine. H,S solubility in diglycolamine, diglycolamine solvent. emoval of acid gases such as C02 and H2S from

Dynamic simulation of MEA absorption process for CO2 capture from power plants

“…In that study, temperature, amine concentration and acid gas (H 2 S and CO 2 ) loading factors were included in the equilibrium constant of amine protonation. Hu and Chakma (1990a) incorporated a dependence of amine concentration and acid gas partial pressure for the equilibrium constant correlation of aqueous diglycolamine (DGA) solutions. Hu and Chakma (1990b) also successfully fitted the VLE data of CO 2 and H 2 S in aqueous amino methyl propanol (AMP) using the same method.…”

Review and selection criteria of classical thermodynamic models for acid gas absorption in aqueous alkanolamines

“…Li and Shen 1993 CO 2 MEA, MDEA -The model was an extension of the work of Hu and Chakma (1990b) in CO 2 solubility in MEA, MDEA, and their mixtures.…”

Analysis of equilibrium CO2 solubility and thermodynamic models for aqueous 1‐(2‐hydoxyethyl)‐piperidine solution

“…In the semi empirical model, the apparent equilibrium constants in terms of concentration (K C ) were applied thus the activity coefficients of the species were not considered during the calculation. 17,19,20 The…”

“…17 The succinct model and its modification were widely adopted in research as they were capable to give reasonable predictive equilibrium CO 2 solubility with little computation. [18][19][20] A robust activity coefficient model was proposed by Deshmukh and Mater based on the extended Debye-Huckel theory to predict CO 2 partial pressure over MEA aqueous solutions. 21 Benamor and Aroua applied the model for mixed DEA and MDEA solutions using a reduced polynomial equation.…”