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:
Nov. 04, 2025
Filed:
Oct. 07, 2021
Evonik Operations Gmbh, Essen, DE;
Holger Wiederhold, Darmstadt, DE;
David Bolz, Frankfurt, 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 catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase (P), containing 1,2-propanediol and phosphoric acid esters of 1,2-propanediol, and an organic phase (P). The method further involves recycling at least part of the separated organic phase (P) to the reaction; heating at least a part of the separated aqueous phase (P) to a temperature of more than 140° C. at a pressure sufficient to maintain at least part of the aqueous phase as a liquid; and recovering 1,2-propanediol from the heated aqueous phase. The heating cleaves phosphoric acid esters of 1,2-propanediol into 1,2-propanediol and phosphoric acid.