Vapor−Liquid Equilibria of Acid Gas−Aqueous Ethanolamine Solutions Using the PC-SAFT Equation of State

Abstract

Using the perturbed-chain statistical associating fluid theory (PC-SAFT), the vapor pressure, saturated liquid density, and heat of vaporization for monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA) were calculated. PC-SAFT accurately described the properties of the pure ethanolamines along the coexistence curve. Then, the vapor−liquid equilibria (VLE) of the aqueous ethanolamine solutions were calculated by temperature-independent binary interaction parameters. Using the binary interaction parameters for the systems DEA + water, DEA + methanol, and methanol + water, the VLE of the ternary system DEA + water + methanol was predicted. The results indicated that PC-SAFT successfully described the equilibrium properties of the aqueous ethanolamine solutions. Finally, the solubilities of carbon dioxide and hydrogen sulfide in the aqueous ethanolamine solutions were predicted and compared to the experimental data. While no adjustable parameters were used, PC-SAFT reasonably described the solubility data.

Experimental investigation and thermodynamic modeling of wax disappearance temperature for n-undecane+n-hexadecane+n-octadecane and n-tetradecane+n-hexadecane+n-octadecane ternary systems

“…[41][42]. In this work, the liquid phase is described by PC-SAFT model [43][44][45] (24) where res a is the reduced residual Helmholtz free energy RT A res / and res A is the residual Helmholtz free energy. According to PC-SAFT model, in the absence of associating and polar molecules, the residual Helmholtz free energy is expressed by [45]:…”

“…description of PC-SAFT and the necessary parameters for calculating properties are provided in Refs [43][44][45]…”

Long chain multifunctional molecules with GC-PPC-SAFT: Limits of data and model

“…Among other applications of SAFT models to alkanolamines we can mention: Button and Gubbins [8] which have applied CK-SAFT to MEA/DEA-water-CO 2 systems, Nasrifar and Tafazzol [9] which have described CO 2 /H 2 S-water-alkanolamine systems with PC-SAFT and Mac Dowell et al [10] which have used SAFT-VR to model CO 2 -MEA-water system.…”

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

“…Button and Gubbins (1999) used SAFT for the modelling of CO 2 -loaded aqueous MEA and DEA solutions, neglecting chemical reactions. The model was improved by Nasrifar and Tafazzol (2010). They considered perturbed-chain SAFT (PC-SAFT) equation of state (EoS) along with chemical equilibria for the correlation of acid gas solubility in aqueous ethanolamine solutions.…”

“…The statistical approach is quite developed and shows promising results in comparison to its counterparts in classical thermodynamics. The detailed development and application of the technique has been aptly discussed elsewhere (Nasrifar andTafazzol 2010, Uyan et al 2015). However, the excessive complexity associated with calculations and the need of sophisticated and nontransparent pure compound data for regression causes a major hindrance to their common application in the field.…”