Chemical Engineering Science, Vol.66, No.5, 897-906, 2011
Separation of p-xylene from binary xylene mixture over silicalite-1 membrane: Experimental and modeling studies
The permeation of single component and binary mixture containing p-xylene and o-xylene through silicalite-1 membrane was studied experimentally in the temperature range of 150-250 degrees C at feed partial pressure of 0.26 kPa for p-xylene and 0.22 kPa for o-xylene. The model for single component flux based on the combination of dual-site Langmuir isotherm and Maxwell-Stefan formulation was derived. The adsorption parameters were estimated by minimizing the difference between the experimental flux and simulated flux. The heat of adsorption and entropy values obtained were in good agreement with the reported values. The effect of feed partial pressure in the range of 0.20-1.50 kPa on xylene flux was predicted using the adsorption parameters and compared with the experimental values. The Maxwell-Stefan diffusion model, in combination with the ideal adsorbed solution (IAS) theory and single-component adsorption parameters was used to predict the permeation flux of p-xylene and o-xylene for binary xylene mixture through the silicalite-1 membrane. The simulated results were in good agreement with the experimental data. The simulated adsorption isotherm in higher temperature range of 150-250 degrees C using the model and derived adsorption parameters could provide useful information for adsorption of xylene molecules on silicalite-1 membrane at a higher operating temperature. (C) 2010 Elsevier Ltd. All rights reserved.