Effective Radial Thermal Conductivity of a Parallel Channel Corrugated Metal Structured Adsorbent

The effective radial thermal conductivity (k eff) of a 2-D analog of a 3-D, parallel channel, corrugated metal, structured adsorbent bed was studied using COMSOL Multiphysics. This 2-D structure consisted of alternating sections of corrugated and flat metal foil sheets, with k eff predicted in 1-D perpendicular to the flat metal foil sheet, i.e., the radial direction in a 3-D cylindrical bed. The effect of the thickness of zeolite coating, thickness of metal, type of metal, type of contact between the metal foil sheets (i.e., metal-to-metal, coating-to-coating and metal-to-coating point contacts, and metal-to-metal imbedded contacts), air gap size between the corrugated and flat metal foil sheets, coating on just one or both sides of the metal foil sheets, alignment of the corrugation between sections, and type of stagnant gas medium on k eff was studied. In all cases, temperature contour plots revealed the minute region around the point contacts, being mostly stagnant gas medium, manifested a significant resistance to thermal conductivity, with the imbedded contacts minimizing the effect. The parametric study revealed direct metal-to-metal contact had the most positive effect on k eff, whether being a point or imbedded contact: k eff respectively varied between 0.561 and 0.726 W m–1 K–1 for SS and 6.66 W m–1 K–1 for Al, showing strong dependence on the metal conductivity and weak dependence on the gas medium and all other parameters. When the corrugated and flat metal foil sheets were either coated with zeolite or separated by an air gap, k eff was significantly reduced, varying between 0.090 and 0.125 W m–1 K–1 in air for SS or Al; k eff also depended strongly on the gas medium but only weakly on the metal conductivity and all other parameters.