Ionic liquids are molten salts with low melting temperatures of ≤ 100 °C and diverse technical applications have been developed within the last decade, due to their attractive properties. Conventional industrial manufacturing methods for ionic liquids show a number of drawbacks, including the use of noxious starting materials, generation of huge amounts of waste and contamination of the final product with corrosive halides and other byproducts.
The Carbonate Based Ionic Liquid Synthesis (CBILS®) is a greener, halide free manufacturing process and is based on the use of alkyl-carbonates as alkylating agents. In In this work the development of CBILS® up to a multi-100kg scale is presented. Critical side reactions typical for alkyl-carbonates could be suppressed by the use of alcohols as solvents, byproducts could be removed by hydrolysis reactions. A large number of diverse starting materials have been screened experimentally and quantum-chemical calculation methods have been established, in order to model thermodynamic functions for the development and application of the CBILS® process. A continuous flow method with improved space-time yield and ultra-high purity was developed and scaled up by a factor of 1000. Several technical application examples are presented, including commercialized products