Mathematical modeling of chloroform adsorption onto fixed‐bed columns of highly siliceous granular zeolites

Abstract

Adsorption of chloroform to granular ZSM‐5 zeolite in fixed‐bed columns was measured and the breakthrough curves predicted with a film‐pore and surface diffusion (FPSD) model. Parameters for the FPSD model were estimated from published correlations and from data taken from batch adsorption rate studies. It was found that the adsorption rate was enhanced with decrease in particle size, however, the total adsorption capacity using granular ZSM‐5 with different particle sizes remained constant. The FPSD model accounted for the effects of axial dispersion, external film transfer resistance, and intraparticle mass transfer resistances. Generally, good agreement between the simulated results and the experimental data was obtained. Furthermore, a sensitivity analysis was carried out to investigate the relative impact of kinetic parameters on the FPSD model predicted breakthrough profiles and showed that the model calculations were insensitive to either the effective pore diffusivity coefficient (Dp,e) or the axial dispersion coefficient (Ez), but were sensitive to the external mass transfer coefficient (kf). The large impact of kf on the results and the relatively low Biot numbers determined by the FPSD model indicated that under the experimental conditions employed in the study, film diffusion was the primary controlling mass transfer mechanism. © 2011 American Institute of Chemical Engineers Environ Prog, 2011

Mathematically modeling fixed-bed adsorption in aqueous systems

“…Currently, a variety of mathematical models have been used to describe and predict the breakthrough curves of a column adsorption system in liquid or gaseous phase (Abu-Lail et al, 2012;Cheknane et al, 2012;Meng et al, 2012;Nwabanne and Igbokwe, 2012;Yi et al, 2012;Zhao et al, 2012), but there is still lack of a comprehensive review of these models. The main objective of the present review is to introduce the modeling of dynamic adsorption in liquid phase.…”

Calibration and uncertainty analysis of a fixed-bed adsorption model for CO2 separation

“…Compared to the wealth of literature on equilibrium and kinetic parameters for mass transfer, relatively few papers have considered sensitivity to heat transfer parameters 9,21,23,31,[40][41][42][43] . This is partially due to the simplifying assumption made in many studies [2][3][4][5][6][7][8][10][11][12][13][14][15][16][17][24][25][26]30,32,34 to neglect heat transfer and treat the entire bed as isothermal. This assumption is made despite the fact that system-level models of cyclic pressure and temperature-swing-adsorption processes are known to be highly sensitive to temperature variations 20 .…”

“…Conclusions in the literature regarding sensitivity to axial dispersion are less consistent; while many researchers concluded that adsorption models are insensitive to axial dispersion 3,4,10,12,14,21,26,30 , others found the opposite to be true 16,24,25,33 . Yet others are equivocal in their conclusions.…”