abstract |
A process for preparation of glycols in which the vapor remaining after the partial condensation of a conventional ethylene oxide stripper overhead vapor stream is contacted with an aqueous solution of ethylene carbonate to recover ethylene oxide. No water need be removed from the enriched ethylene carbonate stream. Carbon dioxide is added and ethylene carbonate is formed by reaction at about 50° to 200° C. and 5 to 150 kg/cm 2 gauge in the presence of a suitable catalyst, preferably about 0.5-20 wt % of an organic phosphonium halide. After stripping off unreacted components, the ethylene carbonate is hydrolyzed to glycols in the presence of the same carbonation catalyst and at temperatures in the range of about 100° to 200° C. and pressures of about 5 to 150 kg/cm 2 gauge. Optionally, ethylene oxide and ethylene carbonate may be co-produced. |