Sorption equilibria, kinetics, and temperature-swing adsorption performance of polyethyleneimine-impregnated silica for post-combustion carbon dioxide capture

Lei Liu, Seongmin Jin, Yongha Park, Kyung Min Kim, Chang Ha Lee

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The sorption equilibria and kinetics of CO2, N2, and H2O on polyethyleneimine (PEI)-impregnated silica (PEI–silica) were studied to determine CO2 capture by temperature-swing adsorption (TSA). The experimental isotherms of CO2 were correlated well by the dual-site Langmuir (DSL) model while those of H2O were well-predicted by the Brunauer–Emmett–Teller (BET) model. The amounts of the components adsorbed at equilibrium were in the order of qH2O>qCO2≫qN2. The isosteric heat of adsorption (Qst) of CO2 on PEI–silica changed from 70 to 55 kJ/mol along the sorption amount. The highly enhanced adsorption affinity of PEI–silica for CO2 resulted in chemisorption, while the adsorptions of H2O and N2 exhibited typical physisorption. PEI–silica exhibited higher selectivity than KOH-treated activated carbon (KOH–AC) for the simulated flue gases, i.e., the mixture of CO2 and N2. Although PEI–silica became hydrophobic, the H2O molecules were expected to affect the CO2 capture process because of their high adsorption amount and rate. The variation in the non-isothermal kinetic behavior of CO2 caused by pressure differed from that of H2O because of the difference between chemisorption and physisorption. PEI–silica exhibited a high CO2-sorption capacity of 2.3 mmol/g (pure CO2 at 70 °C) with a high sorption rate (>90% of saturation within 1 min). Compared with the cyclic test that employs desorption in hot N2, the working capacity decreased more when the desorption was conducted in hot CO2 flow.

Original languageEnglish
Article number118582
JournalSeparation and Purification Technology
Volume266
DOIs
Publication statusPublished - 2021 Jul 1

Bibliographical note

Funding Information:
The authors acknowledge Professor Colin Snape, University of Nottingham, UK, for supplying PEI silica. This work was supported by the National Research Foundation of Korea (NRF) and funded by the Ministry of Science and ICT (2020K1A4A7A02095371).

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) and funded by the Ministry of Science and ICT (2020K1A4A7A02095371).

Publisher Copyright:
© 2021 Elsevier B.V.

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Filtration and Separation

Fingerprint

Dive into the research topics of 'Sorption equilibria, kinetics, and temperature-swing adsorption performance of polyethyleneimine-impregnated silica for post-combustion carbon dioxide capture'. Together they form a unique fingerprint.

Cite this