Method for purifying ethylene carbonate through dynamic crystallization

A method for purifying ethylene carbonate through dynamic crystallization, comprising the following steps:

• adding an ethylene carbonate-containing raw material into a cavity of a crystallization device through a feeding port of the crystallization device under a condition of stirring for dynamic crystallization, wherein the crystallization device further comprises a jacket attached to an outer wall of the cavity and circumferentially disposed along the outer wall of the cavity, the jacket is provided with cooling water therein, a water temperature of the cooling water in the jacket is controlled to be 1-2.5° C. lower than the temperature in the cavity, and a seed crystal is put to initiate crystallization until a granular ethylene carbonate crystal is generated;
• and the crystallization device is a rake dryer;
• wherein the dynamic crystallization comprises stirring performed by rotating a plurality of stirring parts disposed on an inner wall of the cavity at a rotating speed of 15-25 r/min;
• wherein a temperature of the ethylene carbonate-containing raw material entering the cavity is 40-80° C., a water temperature of the cooling water in the jacket is 25-35° C., and when the temperature in the cavity is decreased to 33° C., the water temperature of the cooling water in the jacket is controlled to be 1-2.5° C. lower than the temperature in the cavity;
• wherein the crystal formation in the process of crystallization is initiated by adding the seed crystal at a temperature of 28-29° C.;
• wherein a time for the crystallization is 2-8 h, and the temperature in the cavity during the crystallization is 29-31° C.