Evonik Degussa Gmbh

Thyssenkrupp Industrial Solutions Ag

Evonik Operations Gmbh

Thyssenkrupp Uhde Gmbh

Maik Bernhard

Marc Brendel

Norbert Ullrich

Bernd Jaeger

Wolfgang Wöll

Bärbel Kolbe

Willi Hofen

Johannes Kowoll

Matthias Pascaly

Niels Bredemeyer

David Bolz

Peter Porscha

Franz Schmidt

Manfred Bärz

Johan Anton

Jürgen Schemel

Hans-Christian Dietz

Michael Dopfer

Dana Pfenning

Sören Götz

Juliette Halli

Thomas Noll

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

During start-up of a continuous epoxidation of propene with hydrogen peroxide in a methanol solvent with a shaped titanium silicalite catalyst in a tube bundle reactor with a cooling jacket, cooling medium is fed at the rate for full load of the reactor with a constant entry temperature of from 20&#xb0; C. to 50&#xb0; C., methanol solvent is fed at a rate of from 50 to 100% for full load of the reactor, hydrogen peroxide is fed at a rate that starts with no more than 10% of the rate for full load and is increased continuously or stepwise to maintain a maximum temperature in the fixed bed of no more than 60&#xb0; C. and a difference between the maximum temperature in the fixed bed and the cooling medium entry temperature of no more than 20&#xb0; C., and propene is fed at a rate of from 20 to 100% of the rate for full load, increasing the feeding rate when the molar ratio of propene to hydrogen peroxide reaches the molar ratio for full load.

Process for the epoxidation of propene

Propene is continuously reacted with hydrogen peroxide in a tube bundle reactor comprising a multitude of parallel reaction tubes in the presence of a titanium silicalite catalyst arranged as a fixed bed in the reaction tubes. A cooling jacket encloses the reaction tubes, which has a feed point for cooling medium near the entry of the reaction tubes, a withdrawal point for cooling medium near the end of the reaction tubes and at least one additional withdrawal point upstream of the withdrawal point near the end of the reaction tubes. Cooling medium is fed to the feed point for cooling medium, a part of the cooling medium is withdrawn at the at least one additional withdrawal point and the remainder exits at the withdrawal point near the end of the reaction tubes.

Process and reactor for the epoxidation of propene

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Frankfurt-am-Main, Germany

Maik Bernhard