Catalyst separation in synthesis of ethylene glycol through ethylene carbonate route

To promote industrial application of the ethylene glycol (EG) synthesis through ethylene carbonate method, density and viscosity of the NY-2 catalyst, EG and diethylamide glycol ( DEG) ternary system were determined. Both the viscosity and density decreased with rise of the system temperature. There were a nonlinear relationship between the viscosity and the temperature, and a linear relationship between the density and the temperature. Solubility of NY-2 catalyst in the mixed EG and DEG solvent was investigated. The theoretical recovery of NY-2 catalyst was calculated according to the solubility. Activity of recovered NY-2 catalyst was studied. The results indicated that the NY-2 catalyst could be recovered through cooling crystallization and DEG mass fraction in the tower bottom solvent should be more than 80% to ensure catalyst recovery more than 75%. The temperature of EG and DEG rectifying tower bottom should be below 180°C , which could ensure epoxy ethane conversion declined less than 10%.