Batch adsorption of trichlorotrifluoroethane (freon-113) onto activated carbon — surface diffusivity and pore diffusivity

Activated carbon was found more active than molécular sieve 13X and silica gel in adsorbing 1,1,2 trichloro-1,2,2 trifluoroethane (CFE). Batch adsorption experiments were carried out with activated carbon to adsorb CFE at 15, 25 and 30°C. The adsorption isotherms of CFE on activated carbon were of the Langmuir type: q(C) = q_m KC / (1 + KC) where q^m and K were evaluated for the three temperatures. The measured bulk concentration-time data were interpreted equally well with the surface diffusion model and the pore diffusion model; for the former model the surface diffusivity increased with increasing initial CFE concentration, and for the latter the pore diffusivity was independent upon the initial CFE concentration.