The sterols mixture containing almost the same percentage of compesterol over B-sitosterol and that increasing stirring spedd tends to increase the amount of adsorbed sterols. Temperature has negligible effect on the adsorption selectivity of campesterol and B-sitosterol. Thermodynamic parameters of the adsorption further confirmed the endothermic nature of the adsorption process as shown by the positive heat of enthalpy, accompanied by a positive value of entropy change. The overall Gibbs free energy change during the adsorption process was negative for the experimental range of temperatures, corresponding to spontaneous adsorption. Keywords: adsorption, campesterol, B-sitosterol, zeolite, thermodynamic properties. Arief Widjaja and Yu-Hsuan Chung
