Evonik Operations Gmbh

Thyssenkrupp Industrial Solutions Ag

Evonik Degussa Gmbh

Thyssenkrupp Uhde Gmbh

Hans-Christian Dietz

Marc Brendel

Thomas Haas

Willi Hofen

Bernd Jaeger

Matthias Pascaly

Wolfgang Wöll

Bärbel Kolbe

Michael Kleiber

Manfred Bärz

Franz Schmidt

Jürgen Schemel

Maik Bernhard

Sören Götz

Juliette Halli

A process for making propene oxide involves reacting propene with hydrogen peroxide in the presence of methanol, a titanium zeolite epoxidation catalyst, and nitrogen containing compounds present in an amount of from 100 to 3000 mg/kg of hydrogen peroxide. Non-reacted propene is separated from the reaction mixture; the propene depleted reaction mixture is continuously distilled in a distillation column providing an overhead product stream containing propene oxide and methanol and a bottoms product stream; and propene oxide is separated from the overhead product stream. An acid is added to the propane depleted reaction mixture and/or to the distillation column at the same level or above the feed point for the propene depleted reaction mixture and/or contacted to the feed to the distillation column to provide an apparent pH in the bottoms product stream of from 3 to 4.5, which reduces the nitrogen content of the separated propene oxide.

Process for making propene oxide

In a process for the epoxidation of propene, comprising continuously reacting a propene feed with hydrogen peroxide in the presence of an epoxidation catalyst in a reaction step, using propene in excess to hydrogen peroxide, to provide a liquid reaction mixture comprising non-reacted propene, extra safety measures caused by the presence of oxygen during work-up of the liquid reaction mixture of the epoxidation reaction can be avoided by stripping liquid reaction mixture from step a) with an inert gas to provide an oxygen depleted stripped liquid reaction mixture and a strip gas stream, selecting the amount of inert gas to provide an oxygen concentration in the strip gas stream in the range of from 0.1 to 10% by weight, separating non-reacted propene from the strip gas stream and recycling it to the reaction step, and separating propene oxide from the stripped liquid reaction mixture.

Process for the epoxidation of propene

In a process for the epoxidation of propene, comprising the steps of reacting propene with hydrogen peroxide, separating propene oxide and a recovered propene stream from the reaction mixture, separating propane from all or a part of the recovered propene stream in a Csplitter column, and passing the overhead product stream of the Csplitter column to the epoxidation step, a propane starting material with a propane fraction of from 0.002 to 0.10 is used, the epoxidation is operated to provide a propane fraction in the reaction mixture of from 0.05 to 0.20 and the Csplitter column is operated to provide an overhead product stream which comprises a propane fraction of at least 0.04 in order to reduce the size and the energy consumption of the Csplitter column.

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Hattersheim, Germany

Hans-Christian Dietz