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 (CO2) absorption/desorption has been carried out to estimate the influence of the structural features of distinct amines on their CO2 absorption and regeneration. The absorption has been made at two different CO2 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 (AEPDNH2) solutions, while the CO2 desorption has been performed by heating these solutions. The presence of two or three amino groups in AEE and AEPDNH2, the structure of tertiary amine and alkanolamine, and a nonaromatic ring of pyrrolidine might favor the CO2 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 CO2 loading after regeneration. It appears that AEE and AEPDNH2 would represent interesting compounds which could be used as CO2 absorbents in industrial technologies to prevent CO2 release into the atmosphere.