A thermodynamic model for gas adsorption isotherms

Journal Article · Mon Feb 15 04:00:00 EST 1999 · Journal of Colloid and Interface Science

DOI:https://doi.org/10.1006/jcis.1998.5911· OSTI ID:328307

Riazi, M R; Khan, A R ^[1]

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1. Kuwait Univ., Safat (Kuwait). Chemical Engineering Dept.

In this paper based on the principle of solution thermodynamics for gas-solid equilibrium, a relation is developed to express gas adsorption isotherms. An activity coefficient model based on weight fraction of sorbate in the solid phase has been derived that well describes the behavior of various gases on different types of adsorbents. The proposed model has been evaluated and compared with four other models commonly used for gas adsorption isotherms in the literature. For 12 different systems at various isotherms for the temperature range {minus}128 to 100 C and the pressure range 0.02 to 1219 kPa for 689 data points, the proposed model predicts equilibrium pressure with an average deviation of 5.3%, which is about half of the error obtained from other methods. The proposed model clearly outperforms other available methods such as the vacancy solution theory, the ideal adsorption solution model, and other various modified forms of the Langmuir isotherm. Unique features of the proposed model are its simplicity, generality, and accuracy over the entire pressure and temperature ranges.

• OSTI ID: 328307
• Journal Information: Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 2 Vol. 210; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

2-METHYLPROPANE
40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
ADSORBENTS
ADSORPTION ISOTHERMS
ALLENE
CARBON DIOXIDE
CARBON MONOXIDE
ETHANE
ETHYLENE
HYDROGEN SULFIDES
MATHEMATICAL MODELS
PROPANE
PROPYLENE
THERMODYNAMICS