Use of Zeolite Membrane Reactors for the Combustion of VOCs Present in Air at Low Concentrations

ZSM-5 membranes prepared by liquid phase hydrothermal synthesis on tubular commercial supports and subsequently ion-exchanged with Pt were used in a membrane reactor for the combustion of n-hexane present at low concentrations in air. The investigation deals mainly with the relationship between the permeation properties of the membrane and the performance of the membrane as a reactor. It was found that, rather than aiming for a high-quality membrane, membrane synthesis should be tailored to achieve the presence of a certain concentration of defects, as this improves the performance of the membrane reactor for the reaction tested. For catalytic membranes with suitable permeation properties, nearly complete n-hexane combustion was achieved at 210°C.