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Enhancing CO2 capture of an aminoethylethanolamine‐based non‐aqueous absorbent by using tertiary amine as a proton‐transfer mediator: From performance to mechanism.
- Source :
-
Journal of Environmental Sciences (Elsevier) . Jun2024, Vol. 140, p146-156. 11p. - Publication Year :
- 2024
-
Abstract
- Non-aqueous absorbents (NAAs) have attracted increasing attention for CO 2 capture because of their great energy-saving potential. Primary diamines which can provide high CO 2 absorption loading are promising candidates for formulating NAAs but suffer disadvantages in regenerability. In this study, a promising strategy that using tertiary amines (TAs) as proton-transfer mediators was proposed to enhance the regenerability of an aminoethylethanolamine (AEEA, diamine)/dimethyl sulfoxide (DMSO) (A/D) NAA. Surprisingly, some employed TAs such as N,N -diethylaminoethanol (DEEA), N,N,N',N'',N'' -pentamethyldiethylenetriamine (PMDETA), 3-dimethylamino-1-propanol (3DMA1P), and N,N -dimethylethanolamine (DMEA) enhanced not only the regenerability of the A/D NAA but also the CO 2 absorption performance. Specifically, the CO 2 absorption loading and cyclic loading were increased by about 12.7% and 15.5%–22.7%, respectively. The TA-enhanced CO 2 capture mechanism was comprehensively explored via nuclear magnetic resonance technique and quantum chemical calculations. During CO 2 absorption, the TA acted as an ultimate proton acceptor for AEEA-zwitterion and enabled more AEEA to form carbamate species (AEEACOO−) to store CO 2 , thus enhancing CO 2 absorption. For CO 2 desorption, the TA first provided protons directly to AEEACOO− as a proton donor; moreover, it functioned as a proton carrier and facilitated the low-energy step-wise proton transfer from protonated AEEA to AEEACOO−. Consequently, the presence of TA made it easier for AEEACOO− to obtain protons to decompose, resulting in enhanced CO 2 desorption. In a word, introducing the TA as a proton-transfer mediator into the A/D NAA enhanced both the CO 2 absorption performance and the regenerability, which was an efficient way to "kill two birds with one stone". [Display omitted] [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10010742
- Volume :
- 140
- Database :
- Academic Search Index
- Journal :
- Journal of Environmental Sciences (Elsevier)
- Publication Type :
- Academic Journal
- Accession number :
- 175298044
- Full Text :
- https://doi.org/10.1016/j.jes.2023.06.009