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 (AEPDNH 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.