Chromatographic techniques are used with nonadsorbable and slightly adsorbable tracers to evaluate mass transfer parameters in packed beds. If accurate values of intraparticle diffusivities are to be obtained, it appears that long beds of relatively large particles must be used. Otherwise the moments of the chromatographic peaks are too small for accurate analysis. With adsorbable gases, such precautions are not necessary, and, in addition, the adsorption rate constant can be estimated. However, the intraparticle diffusivity determined for adsorbable gases can include a contribution due to surface migration. The method is applicable to all types of porous particles used as catalysts or catalyst carriers. A combination of measurements of slightly adsorbable and nonabsorbable tracers can be used to approximate the adsorption rate constant for a slightly adsorbable gas such as nitrogen.
No takes yet. Share an insight, caveat, or question.
Cerro et al. (1970) studied this question.