Adsorção de metanol em zeólita 4A em célula diferencial.

Abstract

In last years adsorption was been a very attractive process, principally after the introduction of zeolite adsorbents. However, to project and to optimize adsorption equipment, not only the thermodynamic knowledge but also the kinetic behavior are indispensable. Experimental techiniques are largely used in order to obtain the equilibrium and kinetic parameters. In this work, studies on the kinetics of the adsorption of methanol in 4A zeolites were made by means of a differential cell with contínuos recirculation. All the experiments used an initial concentration of methanol in toluene of about 10% in weight. The influence of liquid flow rate, pellets size and temperature on the rate of adsorption was investigated. The experimental results show that the microporous diffusion is the controlling step. So, the respective model was applied to obtain the diffusion coefficients in the range of temperature between 16°C and 35 °C. The estimation of parameters was made by non linear fitting using the Levenberg-Marquardt algorithm. The proposed model show a good agrement with the experimental data. The energy of activation was calculated from the linearized form of the Arrhenius equation, obtaining a value of 3.36 ± 0.79 Kcal/mol. This value and the diffusion coefficient are in agreement with previous literature data.