METHOD FOR REMOVAL OF MW176 CYCLIC ACETAL AND SOLID ACID CATALYZED REACTIVE STRIPPING OF IMPURITIES FORMED DURING THE PRODUCTION OF 1, 3-PROPANEDIOL

摘要

THIS INVENTION DESCRIBES IMPROVEMENTS UPON A PROCESS FOR THE PRODUCTION OF 1,3-PROPANEDIOL (PDO) WHEREIN AN AQUEOUS SOLUTION OF 3-HYDROXYPROPANAL (HPA) IS FORMED AND THE HPA IS SUBJECTED TO HYDROGENATION TO PRODUCE A CRUDE PDO MIXTURE. ONE IMPROVEMENT ON THIS PROCESS COMPRISES TREATING THE CRUDE PDO MIXTURE WITH AN ACIDIC ZEOLITE, AN ACID FORM CATION EXCHANGE RESIN, OR A SOLUBLE ACID TO CONVERT THE MW176 CYCLIC ACETAL TO MORE VOLATILE MATERIALS WHICH CAN BE EASILY SEPARATED FROM PDO BY DISTILLATION. ANOTHER IMPROVEMENT INVOLVES REMOVING WATER FROM THE CRUDE 1,3-PROPANEDIOL MIXTURE, CONTACTING THE RESULTING MIXTURE WITH A SOLID ACID PURIFIER AT A TEMPERATURE OF FROM ABOUT 50 TO ABOUT 250 °C TO CONVERT THE MW 132 CYCLIC ACETAL TO MORE VOLATILE CYCLIC ACETALS, AND SEPARATING THE MORE VOLATILE CYCLIC ACETALS FROM THE 1,3-PROPANEDIOL BY DISTILLATION OR GAS STRIPPING.