Ethylene glycol and diethylene glycol separation method

The present invention relates to a method for separating ethylene glycol and diethylene glycol, the crude ethylene glycol solution is fed to a refining column, a side draw ethylene glycol to the purified product purified groove, and part of ethylene glycol diethylene glycol taken from the column reactor, to ensure the bottoms temperature below the thermal decomposition temperature of diethylene glycol; ethylene glycol purification column bottom liquid to the recycle column top product returned glycol purification column, kettle liquid is a mixture of diethylene glycol and heavies; bottoms liquid circulating ethylene glycol to the column, the overhead product recovery diethylene glycol, glycerin kettle liquid is a mixture of heavies. The method glycol product high quality, high recovery rate, while high-quality recycled product diethylene glycol, can be used for industrial production of ethylene glycol.