Module: Advanced Separation Processes

2. The crystallization of a pharmaceutical product ( c=2000kg/m3,kV=0.525 ) has been found to exhibit the following kinetic rates: G=5106c1.1B=11014c4 where G=m/s,c=g solute /g solvent, B=#/m3s The product solubility is given by c(T)=0.4722T313.929T2+620.6T+4571 where c= g solute/g solvent, T=C. (i) Estimate the average crystal size (volume-basis) obtained in a batch crystallizer seeded with 50mg of 20m seeds, if the supersaturation is maintained at a constant level of 0.03 g solute/g solvent. Assume the batch time is 2 hours, and the batch volume is 1L. (ii) If the batch process is seeded at 60C and cooled to 20C over 4 hours, compare the productivity of the batch and continuous modes of operation. Assume the solvent has the density of water, and that both systems have an operating volume of 1L