Abstract
Oiling out phenomena (liquid-liquid phase separation phenomena) was often observed in crystallization of low molecular organic compounds such as pharmaceutical and/or agrochemical active ingredients. Oiling out phenomena was reported to affect crystal size, crystal habit and polymorphs of product crystals, but little operation design methods have been reported. In this study, oiling out phenomena of Mono Sodium Glutamate (MSG) was reported, and operational design for the profile of antisolvent addition was suggested in drowning out crystallization of Mono Sodium Glutamate (MSG). Three components solid-liquid equilibrium in the existence of MSG crystals (MSG- water- ethanol systems) was obtained by measuring the equilibrium solution concentration through HPLC, GC and Karl Fischer moisture meter. Over the critical zone, separated two liquid phases were observed (water rich and ethanol rich phase), and then MSG crystallized mainly from the water rich phase non-agitated supersaturated solution. To control optimum supersaturation it was suggested that operation design of antisolvent addition profile was needed, considering oiling out phenomena using the obtained phase diagram. The proposed crystallizaion operation would contribute to prevent nucleation, in order to control crystal size distribution.
