乙二醇单乙酸酯和双乙酸酯的盐析萃取分离

It purified the ethylene glycol monoacetate and ethylene glycol diacetate in the esterification products of the ethylene glycol and acetic acid by using the sodium chloride-ethyl acetate salt extraction system and studied the effects of extraction conditions on the separation result, as well as to compare with the direct esterification-distillation method. The results showed that, the purity of the ethylene glycol monoacetate and ethylene glycol diacetate which preparation by direct esterification-distillation method was too low. Using system of sodium chloride-ethyl acetate for salt-out extraction, when concentration of the sodium chloride was 2 mol/L and the temperature of the system was 25 ℃ can make the monoester and diester effective separation and the monoester can be effectively reclaim when the concentration of sodium chloride increased to saturation. The purity of the obtained monoester was 97~98% and the purity of the diester reached to 99%, moreover the monoester and the diester had no unreacted ethylene glycol.