Time and Bed Height Dependent Concentration vs. Particle Radius Profiles in Packed-bed Adsorption Columns: Non-equilibrium Model Simulation Studies
Advancing the chemical engineering fundamentals
Transport Phenomena in Porous/Granular Media - III (T2-7c)
Keywords: Transport phenomena in granular media, Dynamic modelling, Adsorbent particle concentration profiles, Packed bed adsorption.
Time and Bed Height Dependent Concentration vs. Particle Radius Profiles in Packed-bed Adsorption Columns: Non-equilibrium Model Simulation Studies
Ahmet R. Özdural
Chemical Engineering Department, Hacettepe University, 06532 Ankara/TR.
A new mathematical model and a simulation program have been developed for prediction of the intra-particle uptake profiles during packed bed adsorption process. Usually the understanding of packed-bed adsorption and mathematical modeling approaches to describe intraparticle adsorption and transport of solutes are limited to data obtained from finite bath and packed bed breakthrough studies, with the change of solute concentration in the fluid phase as the only source of information. On the other hand, this approach corresponds to the end result of the actual amount of adsorbed solutes overlaid within the adsorbent, and are therefore of limited use for the development and verification of models describing intraparticle transport.
In packed-bed adsorption column simulation and modeling studies, the complexity of the problem increases if the usually assumed local equilibrium (LE) condition, which neglects all transient resistances, is not invoked. However, the assumption of LE conditions prevail throughout a column is not valid in the dynamic state that exists in a packed-bed adsorption column. In this work, the non-equilibrium model [1] is applied to packed-bed adsorption columns modeling studies. The present study allows the simulation of dynamic intraparticle adsorption and transport profiles during packed bed adsorption process. The simulation results are presented as 2D and 3D plots giving information on the time dependence of “concentration vs. particle radius profiles” at different bed heights. The change of the particle uptake profiles with; (a) interstitial velocity, (b) particle diameter, (c) external film mass transfer coefficient, (d) homogeneous solid diffusivity, and (e) non-linear adsorption isotherm parameters were investigated so as to gain an insight on the effective design of adsorption processes.
Reference
[1] Özdural, A.R., Alkan, A., Kerkhof, P.A.J.M., “Modeling chromatographic columns: Non-equilibrium packed-bed adsorption with non-linear adsorption isotherms”, Journal of Chromatography A, 1041, 77-85, 2004.
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Presented Wednesday 19, 11:40 to 12:00, in session Transport Phenomena in Porous/Granular Media - III (T2-7c).
