Evonik Degussa Gmbh

Thyssenkrupp Industrial Solutions Ag

Evonik Operations Gmbh

Thyssenkrupp Uhde Gmbh

Marc Brendel

Wolfgang Wöll

Willi Hofen

Bernd Jaeger

Maik Bernhard

Jürgen Schemel

Thomas Haas

Michael Benje

Bärbel Kolbe

Manfred Bärz

Hans-Christian Dietz

Norbert Ullrich

Niels Bredemeyer

Michael Dopfer

Johannes Kowoll

Matthias Pascaly

David Bolz

Hubertus Eickhoff

Michael Kleiber

Peter Porscha

Robert Jahn

Johan Anton

Dana Pfenning

Florian Lode

Eduardo Arevalo

Claudia Wallert

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

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 an olefin by continuously reacting the olefin with hydrogen peroxide in a methanol solvent on a fixed bed epoxidation catalyst comprising a titanium zeolite, the hydrogen peroxide is used as an aqueous hydrogen peroxide solution made by an anthraquinone process, the aqueous hydrogen peroxide solution is mixed with methanol to give a feed mixture and this feed mixture is filtered before being contacted with the fixed bed epoxidation catalyst.

Process for the epoxidation of an olefin

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.

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.

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

The invention is directed to a process for concentrating aqueous hydrogen peroxide solution to give at least two hydrogen peroxide streams of different concentration in an apparatus which includes a preevaporator (), a distillation column () and a vapour compressor (). The aqueous hydrogen peroxide solution to be concentrated () is continuously fed into the preevaporator; vapour () produced by evaporation in the preevaporator is fed to the distillation column; bottom product () obtained in the preevaporator is withdrawn as a first concentrated hydrogen peroxide stream (); vapour () produced in the distillation column is withdrawn from the distillation column at the top of the column, compressed by the vapour compressor and used for heating the preevaporator; and the bottom product () obtained in the distillation column is withdrawn as a second concentrated hydrogen peroxide stream (); Concentrated hydrogen peroxide solutions having differing concentrations in the range from 50 to 70% by weight of hydrogen peroxide can be produced at the same time in a freely selectable ratio by feeding part of the bottom product obtained in the preevaporator in liquid form to the distillation column.

Method for concentrating an aqueous hydrogen peroxide solution

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Bruchköbel, Germany

Marc Brendel