The volume expansion effect of amine during CO2 adsorption process: An experimental study combined with theoretical calculations

Yi Chen; Huili Yuan; Haian Xia; Wei Jiang; Can Yang; Gengshen Hu; Youzhao Lan; Maohong Fan

doi:10.1016/j.jcis.2020.03.088

The volume expansion effect of amine during CO₂ adsorption process: An experimental study combined with theoretical calculations

J Colloid Interface Sci. 2020 Jul 15:572:190-197. doi: 10.1016/j.jcis.2020.03.088. Epub 2020 Mar 24.

Authors

Yi Chen¹, Huili Yuan¹, Haian Xia², Wei Jiang³, Can Yang¹, Gengshen Hu⁴, Youzhao Lan¹, Maohong Fan⁵

Affiliations

¹ College of Engineering and College of Chemistry, Zhejiang Normal University, Jinhua 321004, China.
² Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
³ College of Engineering and College of Chemistry, Zhejiang Normal University, Jinhua 321004, China. Electronic address: jiangwei@zjnu.edu.cn.
⁴ College of Engineering and College of Chemistry, Zhejiang Normal University, Jinhua 321004, China. Electronic address: gshu@zjnu.edu.cn.
⁵ Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071, USA.

PMID: 32244079
DOI: 10.1016/j.jcis.2020.03.088

Abstract

The volume expansion effect of amine supported on mesoporous silica during CO₂ adsorption process was found for the first time through well-designed experiments and was further confirmed by theoretical calculations. It was found that the residual pore volume of mesocellular silica foam (MCF) based solid amine sorbent (tetraethylenepentamine (TEPA) supported on MCF) gradually decreased with the increase of CO₂ uptake. Moreover, the surface area, the average diameters of window and cell of MCF show a similar changing trend. This is due to the volume expansion effect of TEPA during CO₂ adsorption process, i.e., the total volume of reaction products of TEPA and CO₂ is larger than that of pure TEPA. The products are very sticky and almost lose the liquidity totally even at 80 °C. The sticky products and the volume expansion effect may increase the mass transfer resistance and are not beneficial to higher CO₂ uptakes especially for solid amine sorbent with higher amine loading due to the decrease of pore size and the residual pore volume. DFT calculations based on simple models also indicate that the total volume of the generated products is much larger than that of unreacted amine, further confirming the volume expansion effect of amine during CO₂ adsorption process. DFT calculations also indicate that the volume is even doubled in the presence of moisture. The volume expansion effect of solid amine sorbent found in this study may help to design the sorbent with high CO₂ capture performance and less the mass transfer resistance.

Keywords: CO(2) capture; Mesoporous silica; TEPA; Volume expansion.