ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Mechanism of Ethanol Vapours Diffusion in Particles of Activated Carbons

D. Bobok and E. Besedová

Department of Chemical and Biochemical Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, SK-812 37 Bratislava

E-mail: daniel.bobok.@stuba.sk

Received: 1 April 2003

Abstract: A gravimetric sorption method was employed for the estimation of effective diffusion coefficients of ethanol vapours in particles of activated carbons Supersorbon HS-4, Dezorex FB-4, Silcarbon SIL-15 Extra. The course of the stepwise adsorption of ethanol from a stream of air and the course of the stepwise desorption of ethanol by a stream of air with lower content of ethanol compared with that used for adsorption, or by a stream of pure air were examined. From measured data the effective diffusion coefficient D_e was calculated for each adsorption and desorption step. The calculated values of D_e were ranging from 4.06x10⁻¹¹ to 1.42x10⁻⁹m²s⁻¹ and the dependences of D_e on adsorbate concentration were found for all activated carbons. The transport of ethanol vapours in pores of activated carbons proceeds via combination of Knudsen diffusion and surface diffusion.

Full paper in Portable Document Format: 581a55.pdf

Chemical Papers 58 (1) 55–63 (2004)