Performing multiphase reactions in microchannels has a great potential to increase the process efficiency, because in addition to the heat transfer the mass transport is intensified and takes place in in the plug flow regime. Parallelization of the reactors is necessary for an industrial application, but is often not economical compared to conventional reactor systems. Economic modules for the parallelization of plug flow reactors have been developed which allow a homogeneous equal distribution of plug flow without parallelization of the expensive equipment. The active measurement and control system enables robust operation of microchannel plug flow reactors with optimal reactor performance and also the use as a multipurpose plant.