The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 2026
Filed:
Oct. 07, 2021
Evonik Operations Gmbh, Essen, DE;
Evonik Operations GmbH, Essen, DE;
Abstract
A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide, in the presence of a phase transfer catalyst and a heteropolytungstate, in a liquid two phase reaction mixture with an organic phase containing an alkylaromatic hydrocarbon solvent. The method then involves separating the reaction mixture into an aqueous phase containing 1,2-propanediol and an organic phase, recycling the oxygen depleted organic phase to the reaction, and recovering 1,2 propanediol from the aqueous phase. The reaction and separation are carried out in liquid flooded vessels at a pressure high enough to suppress desorption of gas from the liquid reaction mixture. The separated organic phase is contacted with a stream of a non-flammable gas to desorb from 10 to 75% of the oxygen dissolved in the organic phase into the stream of non-flammable gas, before recycling the organic phase which purges oxygen safely with little loss of propene.