Adsorption of chlorinated volatile organic compounds on hydrophobic faujasite: correlation between the thermodynamic and kinetic properties and the prediction of air cleaning

This work deals with a thermodynamic and kinetic study of the adsorption of single volatile organic compounds (VOCs) (dichloromethane (DCM), 1,2-dichloroethane (DCA), trichloroethene (TCE) and tetrachloroethene (PCE)) on a dealuminated faujasite Y by simultaneous measurements of the adsorbed amounts, adsorption heats and diffusivities. The type V isotherms and the weak values of derivative enthalpies allowed us to predict that the competitive adsorption of their mixture would be similar to a distillation. This prediction was verified experimentally: the breakthrough curves of VOC mixtures showed that the adsorbate with the higher boiling point displaced the adsorbate with the lower boiling point from the zeolite. The selectivity of the dealuminated faujasite thus decreased as PCE>TCE>DCA>DCM. The regeneration of this zeolite was total at 80 degrees C. (C) 1998 Elsevier Science B.V. All rights reserved.