Possibilities of process intensification using microwaves applied to catalytic microreactors

Pd loaded polymer/carrier composites and their utilisation in catalytic microreactors are presented. The characteristic dimensions on a micro- and nanometre scale make these composites well suited for studying the heating of the catalyst under microwave irradiation compared with traditional heating methods. Using an experimental and a theoretical approach the presence of hot spots during microwave irradiation was investigated. A comparison of the computed results with the experimental ones reveals the accuracy of the mathematical model as well as the absence of a pronounced hot-spot effect. An increase in the reaction rate caused by a temperature rise in the hot spots is a fundamental requirement for process intensification by the combination of microwaves, heterogeneous catalysis and microreactors. Therefore, the developed model has been used to investigate which of the composite material properties would allow a higher increase in the aforementioned effect, opening paths for a realistic combination of all these technologies. (C) 2007 Elsevier B.V. All rights reserved.