Determination of the Structural Features of Distinct Amines Important for the Absorption of CO₂ and Regeneration in Aqueous Solution

Abstract

A study of carbon dioxide (CO 2 ) absorption/desorption has been carried out to estimate the influence of the structural features of distinct amines on their CO 2 absorption and regeneration. The absorption has been made at two different CO 2 flow rates with a series of aqueous 5 wt % ammonia, monoethanolamine (MEA), triethanolamine (TEA), triethylamine, pyridine, pyrrolidine, 2-(2-aminoethylamino)ethanol (AEE), and N-(2-aminoethyl)-1,3-propanediamine (AEP-DNH 2 ) solutions, while the CO 2 desorption has been performed by heating these solutions. The presence of two or three amino groups in AEE and AEPDNH 2 , the structure of tertiary amine and alkanolamine, and a nonaromatic ring of pyrrolidine might favor the CO 2 absorption, while the structural features of ammonia and pyridine seem to be unfavorable. The tertiary alkanolamine is the most easy to regenerate and looses less of its CO 2 loading after regeneration. It appears that AEE and AEPDNH 2 would represent interesting compounds which could be used as CO 2 absorbents in industrial technologies to prevent CO 2 release into the atmosphere.

Carbon dioxide uptake as ammonia and amine carbamates and their efficient conversion into urea and 1,3-disubstituted ureas

“…The chemical absorption of CO 2 by aqueous alkanolamines is an efficient methodology for CO 2 separation in ammonia and hydrogen plants, natural gas sweetening and, in general, for CO 2 removing from industrial exhaust streams [1][2][3][4][5][6][7][8][9][10][11]. However, the critical questions facing this technology are the high energy costs of the amine regeneration and the environmental concerns because of the amine loss by thermal and oxidative degradation [12][13][14][15][16][17].…”

Absorption of CO2 in Biogas with Amine Solution for Biomethane Enrichment

“…An increase in the amine concentration enhanced the amount of CO 2 absorption. Bonenfant, et al [5] studied carbon dioxide absorption with various amine solutions. The absorption solutions were a series of aqueous 5 %wt ammonia, monoethanolamine, triethanolamine, triethylamine, pyridine, pyrrolidine, 2-(2-aminoethylamino) ethanol, and N-(2-aminoethyl)-1,3-propanediamine solutions.…”

An FTIR Spectroscopic Study on the Effect of Molecular Structural Variations on the CO2 Absorption Characteristics of Heterocyclic Amines

“…The lack of a free proton on the nitrogen atom of these amines inhibits carbamate formation. [11][12][13] Instead, tertiary amines are thought to behave as catalysts to facilitate the CO 2 hydrolysis reaction that forms bicarbonate. [11,12,14] This pathway is kinetically and thermodynamically less favourable than that of carbamate formation.…”