Quantitative Study of the Adsorption of Aromatic Hydrocarbons (Benzene, Toluene, and p-Xylene) on Dealuminated Clinoptilolites

Adsorption of benzene, toluene, and p-xylene (BTX) on dealuminated clinoptilolites was investigated in the temperature range of 398-498 K by way of the inverse gas chromatography method. The dealuminated zeolites were prepared via a chosen number of acid treatments of natural clinoptilolite precursors with aqueous HCl. Both natural and acid-leached substrates were characterized by X-ray diffraction, N2 adsorption at 76 K, and BTX adsorption. The Freundlich, Langmuir, and Dubinin-Astakhov adsorption models were found to approximately fit the BTX adsorption data, within the selected temperature range. The uptake degree of these aromatic hydrocarbons was temperature-dependent. Additionally, the degree of interaction between these BTX vapors and the dealuminated clinoptilolite samples was examined through the evaluation of the isosteric heat of adsorption by employing the Clausius-Clapeyron equation.