PHILIPPINE ENGINEERING JOURNAL PEJ 2013; Vol. 34, No. 1: 47-65 Copyright © 2013 Philippine Engineering Journal Received: June 28, 2012 Accepted: November 5, 2012 HEAT AND MASS TRANSFER IN AN ADSORPTION PANEL WITH ROD FINS HEATED BY A RADIANT SOURCE: 3D MATHEMATICAL MODEL Rizalinda L. de Leon 1 , Arturo B. Cortes 2 , Richard Q. Chu 1 1 Department of Chemical Engineering, College of Engineering, University of the Philippines, Diliman, Quezon City 2 Department of Mining, Metallurgical and Materials Engineering College of Engineering, University of the Philippines, Diliman, Quezon City ABSTRACT A 3-D modified equilibrium, static-bed model of adsorption in an adsorption panel with rod fins heated by a radiant heat source is developed and solved using the Method of Lines. The energy equation is transformed to have only one dependent variable hence the accumulation, conduction and generation terms are all expressed in terms of rate of change and gradient of the local bed temperature. Results are compared with experimental data for insight into the heat and mass transfer process occurring in the bed during the cooling and heating phases. Effective surface diffusivities derived agree with literature values obtained by other authors. Keywords: diffusivity, effective thermal conductivity, method of lines 1. INTRODUCTION Adsorption or physical adsorption is a process wherein gas or liquid molecules attach to solid surfaces by van der Waals and electrostatic forces. Adsorption systems can be classified as either dynamic or static. Dynamic adsorption involves fluid flowing through the fixed or fluidized adsorbent bed. The fluid is usually some inert gas that may or may not contain the adsorbate, depending on the operation required. Dynamic beds are characterized by relatively high heat and mass transfer rates that are strongly dependent on fluid velocities. On the other hand, static adsorption occurs in closed systems that are characterized by relatively lower heat and mass transfer rates since the adsorbate does not flow through the bed, but rather disperses into the bed by diffusion or low-velocity convection. Dynamic adsorption has found application in a number of separation processes, such as in the separation of nitrogen and oxygen from air using molecular sieves, waste treatment and purification processes. Static adsorption, on the other hand, is used in refrigeration and heat pump applications. The advantages of adsorption-type refrigerators and heat pumps over the conventional refrigeration systems are that they do not require compressors, are driven by relatively low-temperature heat sources such as solar energy or waste heat, and they have no moving parts. ___________ *Corresponding author: Telefax: +632 929 6640, e-mail address: rldeleon@up.edu.ph (R.L. de Leon)