Fine-chemical and initial ionic-liquid syntheses in microstructured reactors

An overview about inhouse and world-wide use of microstructured reactors and their plants in particular referring to industrial fine-chem. uses will be given. Some conclusions will be drawn which can be transferred also for ionic liq. synthesis. Furthermore, first inhouse results on the use of microstructured reactors for ionic-liq. synthesis will be presented. Chem. micro processing can both improve current chem. processes and act as an enabling technol. towards novel chem. Recently, microstructured reactors step into chem. prodn. and thus micro-reactor process and plant design, including economic incentives, is the issue at this time. The potential of using microstructured reactors and their plants with exemplary new process developments. The formation of ionic liqs. often uses reaction paths which comprise at least one feature which render reactions tailored for use in microstructured reactors - large heat releases which may result in impurity formation, if heat transfer is insufficient. The aim of the performed investigations was to obtain some generic relationships between heat release with connected temp. profile (hot spot formation)in a reactor set-up for continuous and solvent-free ionic-liq. synthesis. For this purpose, a typical micromixer-tube reactor (1/16 in. or 1/8 in.) embedded in a thermostated bath was equipped with seven temp. sensing elements distributed over the length of the tube. Total flow rate was varied from 100 to 400 mL/h and temp. between 30°C to 60°C. Hot spot formation up to 100°C was obsd. esp. for the higher bath temps. Using two tube-reactor sections with smaller internal diam. (1/16 in.) in advance to other larger-sized sections resulted in better temp. control, which demonstrates the multi-scale reactor concept.