In this article, we report the design, fabrication and characterization of a chemical minireactor for direct fluorination. The minichannels (1 mm x 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 degrees 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%. (C) 2011 Elsevier B.V. All rights reserved.