Separation of Mixture of Fatty Acids by Melt Crystallization Using Annular-Cylindrical-Type Cooling Apparatus

Abstract

　Employing a Couette-Taylor-type cooling apparatus equipped with coaxially positioned inner and outer cylinders, we applied melt crystallization to a binary mixture containing stearic acid and oleic acid, with the aim of forming a stearic acid-rich phase as a solid layer on the inner cylinder. As a result of the formation of a Taylor vortex flow in the annular space between the two cylinders, the solid layer exhibited a unique wavy surface. The molar ratio of stearic acid in the solid layer increased on increasing the rotational speed of the inner cylinder. A comparison of the composition of the concave and convex parts of the solid layer revealed the molar ratio of stearic acid on the concave parts to be greater than that on the convex parts, presumably because of the lower growth rate of the solid layer on the concave parts than on the convex parts.