(83s) µ2 - Microwave Assisted Microreactor Processing: Synthesis of Ionic Liquids

Examining the opportunity to prepare ionic liquids in a continuous route the synthesis of 1-methyl-3-hexyl-imidazolium-bromide was investigated under different continuous procedures, using the micro-wave irradiation as well. Experiments were performed in a PARR Multiwave 3000TM microwave oven equipped with a ducts for insertion of tube to ensure a continuous flow. As reactor a micromixer-tube setup made of PEEK and PTFE was used. The tube diameter was 1/8? and different residence times could be adjusted by the tube length as well as by the flow rates of the supply pumps.

As a result it can be turned out that a low microwave energy-supply, partially less than 50 W, and a short residence time of approx. 10 min led to high conversion and selectivity of the targeted product. Also at higher microwave energies (>200W) the residence time could be shortened to less than two minute.