Mathematical Modeling of Single and Multi-Component Adsorption Fixed Beds to Rigorously Predict the Mass Transfer Zone and Breakthrough Curves

Abstract

The aim of the present work is to prepare an adsorption package to simulate adsorption / desorption operation for both single and multi-component systems in an isothermal condition by different mechanisms such as; local adsorption theory and mass transfer resistance (rigorous and approximated methods). Different mass transfer resistance mechanisms of pore, solid and bidispersed diffusion, together with nonlinear isotherms (Longmuir, Frendlich, Sips and Toth) are taken into account in modeling the fixed bed adsorbers. The Extended Longmuir isotherm was found to explain properly the binary and ternary mixtures in adsorption/desorption process.Almost all the mass transfer approximations were explained by the linear driving force, LDF, although the alternative driving force, ADF, approximation was examined in some cases. The numerical solution was the Implicit Method of Lines which converted the partial differential equations to the ODEs then solving them by the Runge-Kutta method. Validation of the models was performed by the experimental data derived from the literature for different types of adsorbents and adsorbates. The sensitivity analyses was carried out to find out variation of the breakthrough curves against some physical and operational parameters such as; temperature, flow rate, initial and inlet concentration and particle adsorbent size. The results revealed excellent agreement of simulated and previously published experimental data.