Estudos de equilíbrio e da cinética da adsorção de metanol-tolueno em zeólitas 4A.

Abstract

In the last years the adsorption has been utilized as an alternative separation process more efficient from the energetic pont of view. For a better comprehension of the adsorption phenomenon of methanol in zeolites 4A, basic studies on the equilibrium and kinetics are necessary. The experimental data of the equilibrium isoterms were obtained by the static method at 15°C, 25°C and 30°C, with concentration varying between 0% to 15,5% in weight of methanol. Batch experiments in finite bath were conduced for the kinetics studies at 15°C and 30°C, looking to the effects of rotation velocity and concentration. Informations for the modelling were obtained from the experiments data, choising the parameters: Langmuir consents in the equilibrium isotherms and the coefficient off diffusion in the microporous for the kinetics of adsorption. The Langmuir model has a good agreement with the experimente data, the saturation constant qs is independent of the temperature in the investigated range. The K parameter is lower for the higher temperatures, except for the 30°C data. The adsorption kinetics depends on the initial concentration of methanol, but no significative influence of temperature was detected. The diffusion coefficients in microporous, obtained by parametic identification from the "Uptake" curves were 5,48 x 10"16 m2/s and 5,99 x 10"16 m2/s for 15°C and 30°C respectively. The propesed kinetics model predicts with good agreement the behavior of methanol adsorption in zeolites 4A in the operational range used is this work.