Flow synthesis of 1-ethyl-3-methylimidazolium ethyl sulfate in a PTFE micro-capillary: an experimental and numerical study

In this work, we have reported continuous flow synthesis of 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid in a PTFE micro-capillary. A Y-shaped microfluidic junction is used to mix the incoming reactants. Effects of independent parameters like velocity, reaction temperature, and micro-capillary diameter on product yield, rate of production, and space–time yield are reported. Yield is seen to increase monotonically as reaction temperature is increased, while it reduces with an increase in diameter of the micro-capillary. A maxima in yield is observed as flow velocity is increased. A space–time yield of 1258.4 g/min.L is obtained at a reaction temperature of 80 ⁰C using a 300 µm micro-capillary. A two-dimensional computational fluid dynamics (CFD) model of the reacting system has been developed to confirm and explain the observed experimental trends. The simulations were able to qualitatively predict the experimental trends. The simulations also investigated the effect of shapes of different obstacles placed in the flow path.