Combustion of volatile organic compounds over platinum-based catalytic membranes

A study of the deep catalytic oxidation of volatile organic compounds (VOCs) contained in air streams on catalytic membrane tubes is presented. The complete combustion of toluene and methyl ethyl ketone as single components and in binary mixtures, with concentrations between 100 and 7000 ppm, was achieved by permeating the VOC-containing stream through a Pt/gamma-Al2O3 catalytic membrane operating under the Knudsen diffusion regime. The membrane combustor performed efficiently, allowing total VOC destruction at low temperatures. In addition, substantial changes in the gas feedrate were accommodated, with only a small variation in the combustion temperatures required. A discussion is presented regarding the ability of the flow-through membrane combustor to attain a lower mass-transfer resistance than a conventional catalytic reactor.