Department of Chemistry

Department of Chemistry University of Oxford

Microwaving Coke

Microwaving Coke

Many industrial petrochemical reactions are carried out over zeolite-based catalysts. The build-up of hydrocarbon side-products (coke) on zeolite catalysts leads to their deactivation and is a ubiquitous problem in the petrochemical and energy transformation industries. Characterising the coke that forms is important to understanding and mitigating catalyst deactivation. Tiancun Xiao, Peter Edwards, and colleagues in the UK and Saudi Arabia have developed a microwave cavity perturbation method to examine the type and quantity of coke produced. They measured the dielectric properties of the coked catalysts by positioning the sample in an electric field that is generated inside a microwave resonant cavity. The dielectric loss value, normalised by the weight of coke formed, provides a unique identifier for various types of coke that can be deposited. Measurements take milliseconds to perform and the technique is non-invasive and fully penetrates the sample, allowing even coke that is contained deep within the porous structure of the catalyst to be probed. more........