Determination by Modeling of the Interactions during the Adsorption Equilibrium of N-Propanol and Ortho Xylene on Activated Carbon Surface

Abstract

Temperature Programmed Adsorption Equilibrium (TPAE) procedure was used to determine the heats of adsorption of ortho xylene and 1-propanol on activated carbon at 300 K. The evolutions of the surface coverage with the adsorption temperature (θ e =f(T a )) were compared to the Temkin model in order to determine the heats of adsorption and reveal the affinity to the surface of activated carbon regarding the polarity of each adsorbate. It has been shown that the heats of adsorption of ortho xylene were E θ0 =100 kJ/mol and E θ1 =62 kJ/mol at 185 Pa, respectively, at low and high surface coverage. Whereas the heats of adsorption of 1-propanol at the adsorption equilibrium was found to be dependent to the surface coverage with E θ0 =67 kJ/mol and E θ1 =58 kJ/mol at 475 Pa. It was shown that ortho-xylene molecules have more affinity to the activated carbon surface than 1-propanol regarding the difference in the heats of adsorption.