Direct Fluorination in Mini- and Microreactors

• Applicants: Professor Dr. Ingo Krossing; Professor Dr.-Ing. Peter Woias
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Inorganic Molecular Chemistry - Synthesis and Characterisation ; Chemical and Thermal Process Engineering
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 234539006

This Transfer Project builds upon work performed in the DFG project Direct Fluorination in Microreactors. Together with Solvay Fluor GmbH, mini- and microreactors for direct fluorination will be developed, tested and applied. The Woias lab will be responsible for the design and fabrication of specifically adapted mini- and microreactors with integrated sensor technologies. Quantum chemical calculations, as well as thermodynamic and kinetic investigations will be performed in the Krossing lab in order to gain deeper insight into the reaction mechanisms and to support the following process optimization at Solvay. Also, tests of the reactor resistance to fluorine, as well as characterization under realistic reaction conditions, will be carried out there. The reactor technology will subsequently be transferred to Solvay Fluor GmbH to be further adapted for company-specific research and application interests, with a specific focus on integration into existing infrastructure. The process will be carried out via iterative design and test of both mini- and microreactors.Research in prior phases has yielded a well characterized minireactor as well as a completed microreactor design process. The completed DFG project, a close collaboration between the Krossing and Woias labs, focused on the concept of a two-phase microreactor for direct fluorination. The fundamental behavior of such devices and chemical reactions was theoretically and numerically modeled and taken as a basis for their design and fabrication as mini- and microreactors. In the Krossing lab significant experience was gained in the direct fluorination of organic and inorganic substrates with these reactors, with a particular focus on cyclic carbonates. In the Woias lab, design, fluid simulation and fabrication were performed. In addition a passivation technique was developed based on electroless nickel plating. This novel nickel technology shall be used as a fabrication platform for micro process engineering, especially for direct fluorination reactors. The project goals include: development of free-standing, self-supporting metallic microchannels for optimized thermal management of the highly exothermic reactions via direct contact with a surrounding cooling medium; direct integration of microsensors in the immediate vicinity of the reaction volume, specifically micro-thermocouples and micro-pressure sensors for process control; realization of reactor walls with transparent segments to allow for optical inline spectroscopy.Solvay Fluor GmbH has longstanding experience with the above-mentioned cyclic carbonates, both in basic research and in commercial manufacturing. To date, the commercial synthesis is performed in classical batch reactors. This project is intended to realize the potential of carrying out direct fluorination in continuous-flow mini- and microreactors, for known as well as for hitherto unknown substances.

• DFG Programme: Research Grants (Transfer Project)
• Major Instrumentation: TBI (1H,19F-BB) NMR Messkopf
• Instrumentation Group: 1790 Spektrometer (Massen-, NMR-, außer 170-178)
• Participating Institution: Solvay Flour GmbH; SFLU-SBURA