We have studied the formation rates of chemical species such as 2-/HCO3 -, amine/protonated amine, and carbonate/protonated carbonate in the course of CO2 absorption at room temperature and concentration changes after CO2 release upon heating at 93 °C for 30 min for aqueous solutions of 12 kinds of tertiary alkanolamines using 13C-NMR spectroscopy. A positive linear correlation was found between the CO2 capture rates of alkanolamines having a normal hydroxyalkyl group and their pKa values. The CO2 capture rates of alkanolamines having a branched hydroxyalkyl group were lower than those in this relationship. The CO2 release amount of each tertiary amine increased with decreasing pKa, as a general trend. Nethyldiethanolamine (EDEA) showed the largest CO2 release amount and a moderately high rate of CO2 absorption.
|Number of pages||6|
|Publication status||Published - 2014 Jan 1|
|Event||12th International Conference on Greenhouse Gas Control Technologies, GHGT 2014 - Austin, United States|
Duration: 2014 Oct 5 → 2014 Oct 9
- Acid dissociation constant
- Tertiary amine
ASJC Scopus subject areas