The realization of efficient microrectification equipment that can be operated intermittently or continuously is reported. The equipment can be used for both analytical and preparative separations of mixtures of liquid substances. Different binary systems were separated. A theoretical separation stage number of 12 was obtained, together with a height equivalent to one theoretical plate of 1.08 cm. Compared to the state of microtechnology, this can be regarded as excellent progress.

Significant process intensification was achieved for the continuously operated Kolbe-Schmitt synthesis of 2,4-dihydroxybenzoic acid (b-resorcylic acid) on laboratory scale by using different approaches opening novel process windows. The results of the optimal process variant, both from the economic and ecological view, were scaled up to the pilot scale. In a first step, the synthesis from resorcinol in aqueous potassium hydrogen carbonate solution was transferred from the capillary reactor to a tailor-made electrically heated microstructured reactor comprising 40 microchannels and enabling a 25-fold increase of the capacity. In a second step, a pilot plant comprising three of such reactors operated in parallel was built and successfully tested with the same reaction.