Large-scale synthesis of ionic liquid [BMIM]Br in a microbore tube

Abstract Large-scale continuous synthesis of ionic liquid [BMIM]Br in solvent-free mode is carried out in a 862 μm diameter microbore tube. A 750 μm diameter T-junction is used to mix the two reactant streams. The effects of reaction temperature, residence time and flow velocity on product yield, space-time-yield (STY), production rate (PR) and specific power consumption are studied. Product yield is observed to increase with an increase in residence time and reaction temperature. The conditions which maximize STY and PR while ensuring that the overall reaction is kinetically controlled and yield is close to 100% are obtained. Maximum STY of 213.1 g/min-L could be attained at reaction temperature of 90 °C and a residence time of 4.93 min. At the same conditions maximum PR of 7.1 kg/day could be attained with 100% yield, the specific power consumption being 27.67 W/kg. Plug flow reactor (PFR) model is found to reproduce experimental data better compared to a laminar flow reactor (LFR) model. Performance of a simple T-junction micromixer is compared with commercially available micromixers and is found to be at par with them.