Anti-solvent crystallization: Particle size distribution with different devices

Particle size distribution (PSD) is one of the critical attributes of crystals. PSD not only influences downstream  processes but also controls final product performance in crystallization. In this work, we have used the model  system of methanol–water-paracetamol for carrying out anti-solvent crystallization to produce paracetamol  crystals. With reference to a base case of anti-solvent crystallization in a stirred tank, we have used three devices  connected to the stirred tank with an external loop with full recycling. A peristaltic pump was used to circulate  the contents of the stirred tank in an external loop comprising a simple tube, a fluidic oscillator (FO), and a  vortex diode (VD). Anti-solvent was introduced at a point lying between the pump and these three devices to  understand the influence of these devices on mixing and potential particle breakage. The PSD of crystals obtained  with these three devices are compared with that of the base case for one supersaturation ratio (SSR = 1.63). The  results indicated the potential of manipulating the PSD of crystals with a strategy of using fluidic devices in an  external loop. The overall arrangement can be potentially extended to continuous crystallization.