Two-stage interaction performance of CO2 absorption into biphasic solvents: Mechanism analysis, quantum calculation and energy consumption

Yao Shen, Han Chen, Junliang Wang, Shihan Zhang, Chenkai Jiang, Jiexu Ye, Lidong Wang and Jianmeng Chen

Applied Energy, 2020, vol. 260, issue C, No S0306261919320306

Abstract: The CO2 capture capabilities of amine-based biphasic solvents have been extensively investigated. However, the mechanism of CO2 absorption into the biphasic solvents has not been adequately examined, even if it is very important for the solvent screening, composition optimization, efficiency improvement and heat duty reduction. In this work, a two-stage interaction mechanism is proposed through CO2 absorption performance, 13C nuclear magnetic resonance analysis, and quantum calculation. The experimental results and quantum calculation revealed that the shift of the absorption mechanism depended on the active amine group in the biphasic solvents. In the first stage, for a high concentration of the active amine group, a proton was transferred from zwitterion to tertiary amines with the primary amines as intermediates. The CO2 absorption rate was controlled by reaction kinetics, which resulted in a high absorption rate and inconspicuous phase change. In the second stage, for a low concentration of the active amine group, the thermodynamics-controlled absorption rate decreased sharply (by 65.2% for 1,4-butanediamine/N,N-dimethylcyclohexylamine) because the proton transferred from zwitterion to tertiary amines directly. Kinetic analysis revealed that, with an increase in the temperature from 298 to 333 K, the reaction rate constants increased by 285–362% at the first stage. However, the equilibrium constants decreased by 17.7–21.3% at the second stage. Taking both the kinetics and energy penalty into account, the triethylenetetramine/N,N-dimethylcyclohexylamine solution with a lean loading of 0.4 mol mol−1 is promising to achieve the high absorption rate and low-energy consumption.

Keywords: CO2 capture; Chemical absorption; Biphasic solvent; Reaction mechanism; Quantum calculation; Energy penalty (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261919320306
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:260:y:2020:i:c:s0306261919320306

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2019.114343

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().