The concept of a Knudsen contactor for total combustion of methyl-ethyl ketone (MEK) in diluted streams using Fe2O3 as catalyst has been investigated in this work. In this type of gas-solid contactor, mass transfer resistances are greatly reduced since reactants are forced to permeate across the membrane wall where the catalyst is dispersed. Essentially, complete combustion of methyl-ethyl ketone (used as an example of volatile organic compounds (VOCs)) in the range 500-2000 ppm V was achieved at temperatures as low as 255 degreesC. (C) 2003 Elsevier B.V. All rights reserved.