Premium
Modelling highly skewed chromatographic response curves
Author(s) -
Gelbin D.,
Wolff H.J.,
Friedrich S.
Publication year - 1982
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690280202
Subject(s) - tracer , diffusion , yield (engineering) , adsorption , particle (ecology) , breakthrough curve , chemistry , skew , porosity , chromatography , constant (computer programming) , materials science , thermodynamics , geology , composite material , physics , organic chemistry , oceanography , astronomy , computer science , nuclear physics , programming language
A model is presented in which damaged pores are distributed throughout a network of undamaged pores within a spherical particle. The differential equations are solved according to the numerical procedure of Haynes, Jr. (1975). The model is intended to simulate more highly skewed chromatographic response curves than the two‐zone model recently proposed by Chou and Hegedus (1978). Pulse chromatographic measurements in fresh NaMgA zeolites using i‐butane as a tracer which only enters the macropores yield response curves with relatively low skew, which are readily fitted by a system of equations accounting for diffusion in a monodisperse pore system. For hydrothermally treated zeolites effective diffusivities and Henry constants are considerably lower and the skew higher than in fresh samples. Curve fitting with the model proposed below is quite satisfactory, and the characteristic parameters determined are approximately constant at the flowrates studied. Application of the model should not be restricted to hydrothermally treated zeolites, but may be extended to catalysts or adsorbents with macroporous structures damaged by other forms of ageing.