US 11,873,285 B2
Process for making propene oxide
Maik Bernhard, Radeburg (DE); Juliette Halli, Frankfurt am Main (DE); Marc Brendel, Bruchkoebel (DE); Sören Götz, Kahl am Main (DE); and Hans-Christian Dietz, Hattersheim (DE)
Assigned to Evonik Operations GmbH, Essen (DE); and thyssenkrupp Uhde GmbH, Dortmund (DE)
Filed by Evonik Operations GmbH, Essen (DE); and thyssenkrupp Uhde GmbH, Dortmund (DE)
Filed on Oct. 12, 2022, as Appl. No. 18/046,150.
Claims priority of application No. 21202651 (EP), filed on Oct. 14, 2021.
Prior Publication US 2023/0120363 A1, Apr. 20, 2023
Int. Cl. C07D 301/12 (2006.01); C07D 301/32 (2006.01); C07D 303/04 (2006.01)
CPC C07D 301/12 (2013.01) [C07D 301/32 (2013.01); C07D 303/04 (2013.01)] 16 Claims
 
1. A process for making propene oxide, comprising:
a) reacting propene with hydrogen peroxide in the presence of a methanol solvent, of a titanium zeolite epoxidation catalyst, and of at least one nitrogen containing compound present in an amount of from 100 to 3,000 mg/kg of hydrogen peroxide, at a molar excess of propene to hydrogen peroxide, to provide a reaction mixture;
b) separating all or a part of non-reacted propene from the reaction mixture of a), to provide a propene depleted reaction mixture;
c) subjecting the propene depleted reaction mixture of b) to a distillation in a distillation column, to provide an overhead product stream comprising propene oxide and methanol and a bottoms product stream comprising methanol and water; and
d) separating the propene oxide from the overhead product stream of c);
wherein c) is performed after contact with and/or in the presence of an acid provided in an amount providing an apparent pH in the bottoms product stream of from 3 to 4.5.