The
present work experimentally studies the antisolvent continuous
crystallization of flufenamic acid using the coiled flow inverter
(CFI) as a novel crystallization device. A multistage antisolvent
addition strategy was evaluated. The experimental results show that
the mean crystal size increased with the number of antisolvent addition
points in the CFI. The continuous CFI crystallizer produced crystals
of a smaller size with narrower size distributions as compared to
the Kenics crystallizer and tube crystallizer without mixing elements
at the same process conditions. The effect of the number of flow inversions
on the size distribution of the flufenamic acid crystals was studied.
The mean crystal size and the coefficient of variation decreased as
the number of equally spaced 90° bends increased. Using the population
balance equation, it was found that an ideal plug flow model can accurately
describe the CFI continuous crystallization process. Overall, this
work shows that the CFI crystallizer successfully intensifies the
continuous antisolvent crystallization process.