Properties of ceramic foam catalyst supports: mass and heat transfer

Mass and heat transport properties have been determined for 30 PPI alpha-Al2O3 ceramic foam containing 6 wt.% gamma-Al2O3 washcoat. The foam was loaded with 5 wt.% platinum and the rate of carbon monoxide oxidation measured for a 0.3 cm, cylindrical segment of the foam operating with mass transfer controlling at 550degreesC. This gave a mass transfer factor versus Reynolds number correlation that was equivalent to a packed bed of particles. A correlation for the radial heat transfer coefficient in a bed of ceramic foam was determined by measuring outlet temperatures achieved when air at varying flow rates and inlet temperatures was passed through a bed of foam pellets. Correlation parameters of a 1D model were fitted from 700 to 1000degreesC using a Simplex optimization routine. Radial heat transfer coefficients were two to five times higher than those predicted from packed bed correlations. (C) 2003 Elsevier Science B.V All rights reserved.