PROBLEMS IN THE DETERMINATION OF EFFECTIVE DIFFUSION COEFFICIENTS OF GASES AND LIQUIDS USING THE UP-TAKE TECHNIQUE

Abstract

Diffusion processes play an important role in many areas of science and technology. Since pore diffusion processes strongly depend on the pore texture of the porous solid, a desired value of an effective diffusion coefficient, D, has to be determined experimentally. Although, several measuring techniques have been described in the open literature, only a few of them can be used to set up a routine procedure. One of these methods is the so-called Up-Take Technique. The evaluation of the experimental data in this case, however, can lead to difficulties which will be discussed in detail.