Prediction of VOCs adsorption equilibria on activated carbon in supercritical carbon dioxide over a wide range of temperature and pressure by using pure component adsorption data: Combined approach of the Dubinin–Astakhov equation and the non-ideal adsorb

• A new predictive model for VOCs adsorption equilibria in supercritical CO2 was proposed.
• The model was developed by using the Dubinin–Astakhov equation and the non-ideal solution theory.
• VOC and CO2 pure adsorption data were measured with a gravimetric method.
• The proposed model demonstrated accurate prediction compared to conventional models.

A new prediction methodology by using the non-ideal adsorbed solution theory (NIAST) coupled with the Dubinin–Astakhov (DA) equation is proposed for volatile organic compounds (VOCs) (acetone, n-hexane, toluene, methanol and n-decane) adsorption equilibria under supercritical carbon dioxide conditions at temperatures from 313 to 353 K and at pressures from 4.2 to 15.0 MPa. Pure components adsorption data of the each adsorbate were measured by using a gravimetric method, and these pure component data were used to predict the binary systems. The proposed DA–NIAST model could provide accurate predictions at a wide range of temperature and pressure in comparison with the conventional methodologies by combination of the ideal adsorbed solution theory (IAST) and the Langmuir equation.

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