The Open Transport Phenomena Journal

2011, 3 : 40-48
Published online 2011 September 19. DOI: 10.2174/1877729501103010040
Publisher ID: TOTPJ-3-40

Effect of Isotherm Shape on Mass Transfer in an Adsorbent Particle; An Isothermal Adsorption Process

Zeynep Elvan Yildirim , Gamze Gediz Ilis , Moghtada Mobedi and Semra Ulku
Energy Engineering Program, Izmir Institute of Technology, Urla 35410 Izmir, Turkey.

ABSTRACT

The mass diffusion equation and corresponding initial and boundary conditions were non-dimensionalized for a spherical adsorbent particle in an infinite adsorptive medium to reduce number of independent governing parameters into two as mass transfer Biot number and dimensionless isotherm. The changes in local and average adsorbate concentration throughout the adsorption process were calculated and plotted for different values of mass transfer Biot numbers (ranging from 0.5 to 750) and for five different isotherm shapes. The obtained results indicated that the isotherm shape influences dimensionless period of adsorption, if the external mass transfer resistance is significant in the process. For those cases, the total dimensionless adsorption period for a convex shape isotherm is shorter than a concave one.

Keywords:

Isotherm shape, mass transfer, physical adsorption, solid diffusion.