EFFECTIVE DIFFUSIVITIES IN ACTIVATED CARBON PELLETS BY A DYNAMIC WICKE-KALLENBACH APPARATUS

Abstract

A simple step response technique is presented to determine effective diffusivities in adsorbent pellets using non-adsorbing tracers NaCl and KCl. The diffusion cell used consists of a pellet and two stirred vessels of extremely different sizes which are connected to both sides of the pellet.
An analytical solution is presented for boundary conditions different from those reported previously. The effective diffusivities can be evaluated from an arbitrary datum point of a breakthrough curve which is a function only of diffusion time, provided the volume ratio of pellet to detector chamber is specified.
Experimental values of effective diffusivities were reasonable in comparison with those reported for these kinds of activated carbon pellets.