Multiphase minireactor system for direct fluorination of ethylene carbonate

In this article, we report the design, fabrication and characterization of a chemical minireactor for direct fluorination. The minichannels (1 mm × 1 mm) were investigated for gas–liquid flow in a slug-flow regime. The generated slugs were analyzed for a variation of gas and liquid flow rates and the measured lengths correspond with microfluidic models and measurements. From the slug lengths, the interfacial area per liquid flow was determined. As a first test reaction, the fluorination of ethylene carbonate (EC) was investigated. The multiphase minireactor facilitates a continuous direct fluorination of EC at 22 °C with up to 88% fluorine concentration. The reaction could be run almost isothermic in the entire reaction minichannel and the chemically resistant nickel coating showed no corrosion after 100 h of process time. Nuclear magnetic resonance (NMR) spectroscopy showed the cyclically running reaction to have unprecedented fluorine conversation rates of up to 95% and yields of 60–79%.

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► Multiphase minireactor system for exothermic reactions with a T-shaped nozzle, a meander reaction minichannel and an active heat sink.
► The multiphase in the reaction minichannel is analyzed for slug length and the resulting interfacial area.
► Direct fluorination of EC is performed in the minireactor system and analyzed with NMR.