Thermodynamics and Equilibrium Solubility of Carbon Dioxide in Diglycolamine/Morpholine/Water

Abstract

Carbon dioxide solubility was studied in 3.5 m (23.5 wt %) morpholine (MOR), 17.7 m (65 wt %) 2-aminoethoxyethanol (diglycolamine or DGA), and 3.6 m MOR + 14.7 m DGA (11 wt % MOR + 53 wt % DGA). CO 2 solubility was determined by dynamic measurements with a wetted wall contactor. Carbamate and bicarbonate concentrations were determined by 13 C NMR in solutions loaded with 13 CO 2 . The data are represented by the electrolyte NRTL model. At a given CO 2 loading (mol/mol amine), the CO 2 vapor pressure over 3.5 m MOR is 10 to 1000 times greater than 17.7 m DGA. In 3.6 m MOR + 14.7 m DGA, the CO 2 vapor pressure is 5 to 7 times greater than in 17.7 m DGA at high CO 2 loading, but the same below 0.2 loading. MOR carbamate is less stable than DGA carbamate by a factor of 7 to 10 from (300 to 333) K. The model predicts that MOR vapor pressure is 100 times greater than DGA over 3.6 m MOR + 14.7 m DGA from (313 to 333) K. The heat of CO 2 absorption in the blend is equivalent to 17.7 m DGA up to 0.35 loading but is 40 % lower at 0.5 loading. The working capacity of the blend is 17 % less than 17.7 m DGA.

Fixation of Ethylenediamine Using Magnesium Tetraphenylporphyrin for CO2 Capture

“…The values of the thermodynamic parameters are shown in Table-1. From Fig. 5, MgTPP can interacts with ethylenediamine to form 1: 1 molecular adducts at T = (298.15 to 313.15) K. From the Table 1, the Kassoc value of the interaction is 3.901 at T = 298.15 K. However, the binding constants between CO2 and amines are about 10 24,25 . So CO2 gas can compete with MgTPP for ethylenediamine easily.…”

Experiments and Modeling of Absorption of CO2 by Amino-cation and Amino-anion Dual Functionalized Ionic Liquid with the Addition of Aqueous Medium

“…The principle of distinguishing the chemical dissolution and the physical dissolution in the total solubility of CO 2 had been discussed in ref . The equilibrium constants for reactions – can be found in ref . The constants in eq for K 1 to K 7 , are listed in Table .…”

Understanding the corrosion of CO2-loaded 2-amino-2-methyl-1-propanol solutions assisted by thermodynamic modeling

“…The temperatur p n nt nry's l w onst nt of CO 2 in AMP was selected from literature (Dash et al, 2011). The employed and estimated parameters for the temperature p n n of th nry's l w onst nt (P /mol fr tion) of CO 2 in AMP and water and for the mole fraction based equilibrium constants of reactions 3 through 7 are listed in Tables 1 and 2 (Al-Juaied and Rochelle, 2006;Austgen et al, 1989;Dash et al, 2011).…”

“…The parameters for the temperature dependent equilibrium constant for dissociation of protonated AMP, reaction 7, were selected from the default values in the Aspen Plus ® version 8.0 data bank without any alteration. a (Al-Juaied and Rochelle, 2006) In this study, the activity coefficient model based on electrolyte nonrandom twoliquid (electrolyte-NRTL) theory for aqueous electrolyte systems is used to represent liquid-phase activity coefficients (Austgen et al, 1989;Chen et al, 1982;Chen and Evans, 1986;Mock et al, 1986).…”