Process intensification in a microwave heated fine-chemical milli-plant at large scale operation

The integration of micro reactor technology and microwave heating has been investigated for two important classes of fine-chemical reactions, leading to improved catalyst surface and selective catalyst heating. A wall-coated micro reactor and a micro fixed-bed millireactor were designed and applied in the Ullmann-type C-O coupling of phenol and 4-chloropyridine and the Simmons-Smith cyclopropanation of styrene with ethyl diazoacetate. Volumetric microwave heating of the reactant fluids and local heating of CuZn/TiO2 catalyst could be established and resulted into an unprecedented continuous Cu-catalyzed liquid phase C-O coupling reaction with product yields up to 80%.