Chemisorption of carbon dioxide on potassium-carbonate-promoted hydrotalcite

K. B. Lee, A. Verdooren, H. S. Caram, S. Sircar

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158 Citations (Scopus)


New equilibrium and column dynamic data for chemisorption of carbon dioxide from inert nitrogen at 400 and 520 °C were measured on a sample of potassium-carbonate-promoted hydrotalcite, which was a reversible chemisorbent for CO2. The equilibrium chemisorption isotherms were Langmuirian in the low-pressure region (pCO2 < 0.2   atm) with a large gas-solid interaction parameter. The isotherms deviated from Langmuirian behavior in the higher pressure region. A new analytical model that simultaneously accounted for Langmuirian chemisorption of CO2 on the adsorbent surface and additional reaction between the gaseous and sorbed CO2 molecules was proposed to describe the measured equilibrium data. The model was also capable of describing the unique loading dependence of the isosteric heat of chemisorption of CO2 reported in the literature. The column breakthrough curves for CO2 sorption from inert N2 on the chemisorbent could be described by the linear driving force (LDF) model in conjunction with the new sorption isotherm. The CO2 mass-transfer coefficients were (i) independent of feed gas CO2 concentration in the range of the data at a given temperature and (ii) a weak function of temperature. The ratio of the mass-transfer zone length to the column length was very low due to highly favorable CO2 sorption equilibrium.

Original languageEnglish
Pages (from-to)30-39
Number of pages10
JournalJournal of Colloid and Interface Science
Issue number1
Publication statusPublished - 2007 Apr 1
Externally publishedYes

Bibliographical note

Funding Information:
The authors are grateful to J. McMullen, M. Beaver, and J. Purcell for construction of the test apparatus. The work was partly supported by the Pennsylvania Infrastructure Technology Alliance grants (PITA-442-04 and PITA-542-5), by the U.S. Department of Energy under cooperative agreement DE-PS26-04NT-42454, and by a donation from Air Products and Chemicals, Inc.


  • Carbon dioxide
  • Chemisorption
  • Equilibrium
  • Kinetics
  • Model isotherm
  • Promoted hydrotalcite

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry


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