- Title
- Characterisation and kinetic study of carbon dioxide absorption by an aqueous diamine solution
- Creator
- Yu, Bing; Yu, Hai; Li, Kangkang; Yang, Qi; Zhang, Rui; Li, Lichun; Chen, Zuliang
- Relation
- Applied Energy Vol. 208, p. 1308-1317
- Publisher Link
- http://dx.doi.org/10.1016/j.apenergy.2017.09.023
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2017
- Description
- Aqueous monoamine solvents have been extensively studied for the purpose of CO₂ absorption to reduce emissions from sources such as industrial power stations. However, to improve the economic viability of carbon capture technologies, solvents with higher CO₂ absorption capacity and faster kinetics are urgently required. Diamines comprising two amino groups have potentially higher CO₂ absorption capacity and rates than monoamine solvents, such as monoethanolamine, and could be superior liquid absorbents for CO₂ absorption. In this study, we selected six linear diamines with a structure of NH₂(CH₂)n-R (n = 2 or 3; R = NH₂, NHCH₃ or N(CH₃)₂) and four monoamines with a structure of NH₂(CH₂)n-R (R = OH, CH₃ or CH(OH)CH₃). We then investigated the effect of diamine molecular structure on absorption kinetics and capacity using a bubble column, and confirmed the observed kinetic behaviours of selected diamines at different concentrations using a wetted-wall column and stopped-flow reactor. Under the conditions studied, all selected diamines had an absorption capacity of more than 0.78 moles of CO₂ per mole of amine, which far outstrips the capacity of monoamines. The hydroxyl group decreased the rate of CO₂ absorption, while the methyl group and longer chain lengths increased CO₂ absorption rate and capacity; the tertiary amino group exhibited the lowest kinetic performance. N-methylpropane-1,3-diamine (MAPA) had both the fastest absorption rate and the highest mass transfer coefficient. Using Fourier-transform infrared spectroscopy and ¹³C nuclear magnetic resonance, we elucidated the mechanism involved in the reaction of MAPA with CO₂. Our research provides a method for the future selection and design of new diamines for post-combustion CO₂ capture.
- Subject
- diamine; CO₂ capture; molecular structure; kinetics
- Identifier
- http://hdl.handle.net/1959.13/1395599
- Identifier
- uon:33909
- Identifier
- ISSN:0306-2619
- Language
- eng
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