M. Giona et al., 2-STEP ADSORPTION MODELS IN MOLECULAR-SIEVES, Chemical engineering journal and the biochemical engineering journal, 58(1), 1995, pp. 21-32
Starting from analysis of the behaviour of peak retention time vs. the
adsorption constant and vs. the mass transfer coefficient, we propose
a simple macroscopic model describing adsorption in molecular sieves
at high Peclet numbers and at low temperatures. The model is based on
the hypothesis that adsorption kinetics evolve through the superpositi
on of an instantaneous adsorption step and a slower step controlled by
mass transfer resistance. A detailed moment analysis is performed by
comparing the results of the two-step model with those deriving from c
lassical adsorption models (linear driving force model and macropore-m
icropore model) and with experimental chromatographic data of H-2-D-2
adsorption on NaCa-Mordenite. The experimental results at low temperat
ures validate the proposed model.