Catalysis Today, Vol.105, No.3-4, 378-384, 2005
Optimization of structured catalyst carriers for VOC combustion
Typical catalytic afterburners do not offer sufficient mass transport properties for volatile organic compounds (VOC) combustion. Therefore, displaying highly increased transport properties, short-channel microstructures of various geometries and wire gauze structures have been designed and evaluated as an alternative to monoliths. The structures have been deposited with Pd promoted cobalt oxide catalyst using Langmuir-Blodgett technique. The catalyst has proved to meet the specific requirements of VOC combustions and also not to change the microstructure geometry. According to the models of mass transfer proposed in this study, short-channel and gauze structures have up to 15 times higher mass transfer coefficients, and up to 90 times higher volumetric coefficients than standard monoliths. The results of experiments performed using the stacked wire gauze structure were in accordance with the results derived from modelling giving high convergence for higher Reynolds number values (> 15). According to the evaluation criteria proposed by us, the majority of short-channel microstructures have shown very high mass transfer efficiency both in diffusional regime (40 times higher than monoliths) and in levelled diffusional and kinetic regime (over 20 times higher). (c) 2005 Elsevier B.V. All rights reserved.
Keywords:microstructured catalyst;gauze;mass transfer;diffusional limitation;performance efficiency;Langmuir-Blodgett deposition