Absorption of CO₂ in aqueous blend of methyldiethanolamine and arginine

Abstract

The objective of this research is to study for the first time the effect of adding L-arginine (Arg) amino acid on the solubility of carbon dioxide in aqueous solution of N-methyldiethanolamine (MDEA). The study was carried out at different mixing ratios of MDEA and Arg at a total concentration of 2 moles per litre. The CO 2 partial pressure varied from about 10 to 100 kPa, and the temperature varied from 293 K to 323 K. The experimental results showed improved solubility of CO 2 with the addition of Arg at CO 2 partial pressures below 20 kPa. However, for CO 2 partial pressure of above 20 kPa, the addition of Arg caused a decrease in the solubility of CO 2 . The obtained loading data were correlated using a semiempirical (SE) vapour liquid equilibrium (VLE) model with an average absolute deviation (AAD) less than 4.1% between the predicted and the experimental values. An estimation of the heat of CO 2 absorption in the solution was obtained using an analytical expression for ΔH abs derived from the SE model and was found to be in the range of 29-to 40-kJ/mole CO 2 . From the finding of this work, it is anticipated that the studied novel blended solvent will effectively reduce CO 2 capture costs as the CO 2 content of most gas streams is less than 20% by volume, which is specifically true for natural gas and a large number of industrial flue gas streams.

Intensification of Amino Acid Ionic Liquids with Different Additives for CO2 Capture

“…As illustrated in Figure , the solubility of CO 2 increases with the rising pressure and decreasing temperature. Considering the 1:1 reaction mechanism, the well-known thermodynamic model was shown in eq to correlate CO 2 solubility data with temperatures ranging from 298.15 to 323.15 K. , where x is the amount of CO 2 absorbed in the absorbent (mol/kg), and P x is the partial pressure of CO 2 at absorption of x (bar).…”

Comparison of CO2 absorption performance between methyl‐di‐ ethanolamine and tri‐ethanolamine solution systems and its analysis in terms of amine molecules

“…Nevertheless, these two tertiary amines are not used as the main solvents to absorb CO 2 in the process due to their slow absorption rate. Therefore, tertiary amines have not been significantly studied as the independent absorbents, but rather as subsidiary solvents to improve the absorption performance and the stability of the process using other main solvents 23–25 . However, the CO 2 absorption capacity of MDEA and TEA solutions can be theoretically maximized to 1.0 mol CO 2 ·mol −1 amine even with a high‐concentration solution because they follow different absorption mechanisms from primary and secondary amine systems.…”

Experimental Measurement of Carbon Dioxide Solubility in Aqueous N-Methyldiethanolamine + 2-(2-Aminoethylamino) Ethanol + Sulfolane and Diethanolamine + 2-(2-Aminoethylamino) Ethanol + Sulfolane Hybrid Solvents at Various Temperatures and High Pressure

“…9 Although the amines remove CO 2 efficiently, they pose specific inherent economic and environmental problems such as high regeneration cost, high thermal and oxidative degradation, volatility, and toxicity. 5,10,11 Accordingly, these weaknesses have led to the development of "physical" methods. 12 Despite chemical solutions, the noncorrosive physical ones do not have stoichiometric limitations for CO 2 absorption.…”

“…On the other hand, it was publicized that adding an insignificant quantity of fast-reacting alkanolamines (like AEEA) to conventional tertiary alkanolamines (like MDEA) represents the advantages of combining the high CO 2 capture ability of tertiary alkanolamines and a high absorption rate caused by the additive. 10 Therefore, among the alkanolamines that may be employed as an additive to aqueous MDEA solutions, it was found that AEEA is a great candidate in the gas treatment process. 22 Guo et al 23 reported the solubility of CO 2 in aqueous solutions of AEEA and its blend with MDEA and 2-amino-2-methyl-1-propanol (AMP) at three different temperatures and partial pressures of CO 2 up to 800 kPa.…”