Correlation of CO2 absorption performance and electrical properties in a tri-ethanolamine aqueous solution compared to mono- and di-ethanolamine systems.

Abstract

The study investigates the correlation of CO2 absorption performance and electrical properties in a tri-ethanolamine (TEA) aqueous solution compared to the mono-ethanolamine (MEA) and di-ethanolamine (DEA) systems. While the absorption rate of the MEA and DEA systems varies with amine concentration, and the maximum rate is observed at 30.0 and 50.4 wt% amine solution, respectively, the rate of the TEA system according to concentration follows a parabolic curve and the maximum rate is observed at 15.0 wt% solution. The ionic conductivity of carbamic acid in the TEA system is estimated to be the smallest with 37.60 S cm2/mol z and the decreasing ratio of ionic activity coefficient according to the concentration is the largest. The results are mostly attributed to differences in amine molecular structure and the unique reaction mechanism. Finally, based on these values, the correlation equations are obtained to estimate CO2 absorption capacity by measuring electrical conductivity in situ.