Evonik Degussa Gmbh

Thyssenkrupp Industrial Solutions Ag

Degussa Aktiengesellschaft

Uhde Gmbh

Evonik Operations Gmbh

Thyssenkrupp Uhde Gmbh

Wolfgang Wöll

Thomas Haas

Willi Hofen

Guido Stochniol

Claudia Brasse

Bernd Jaeger

Norbert Ullrich

Marc Brendel

Georg Thiele

Bärbel Kolbe

Jürgen Glenneberg

Niels Bredemeyer

Manfred Bärz

Maik Bernhard

Jürgen Schemel

Hans-Christian Dietz

Johannes Kowoll

Matthias Pascaly

David Bolz

Hubertus Eickhoff

Michael Kleiber

Peter Porscha

Werner Pohl

Franz Schmidt

Robert Jahn

Percy Kampeis

Michael Dopfer

Dana Pfenning

Gerald Moroff

José Berges

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.

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

In a process for the epoxidation of propene, comprising the steps: reacting propene with hydrogen peroxide in the presence of a titanium silicalite catalyst and a methanol solvent; separating non-reacted propene and propene oxide from the resulting reaction mixture to provide a solvent mixture comprising methanol and water in a combined amount of at least 90% by weight; and feeding this solvent mixture as a feed stream to a continuously operated methanol distillation column at a feed point in the middle section of said column to provide an overhead product comprising at least 90% by weight methanol and a bottoms product comprising at least 90% by weight water; the addition of a liquid defoamer, having a solubility in the feed stream of less than 10 mg/kg at 25&#xb0; C. and a surface tension at the liquid air interface of less than 22 mN/m at 20&#xb0; C., at or above the feed point in an amount exceeding the solubility of the liquid defoamer in the feed stream suppresses foam formation in the methanol distillation column.

In a process for the epoxidation of an olefin, where a mixture comprising olefin, hydrogen peroxide, water and methanol with a weight ratio of water to methanol of less than 1 is passed through a catalyst fixed bed comprising a shaped titanium silicalite catalyst, catalyst breakage is reduced by conditioning the dry catalyst with at least one conditioning liquid comprising water and from 25 to 45% by weight methanol.

Process for the epoxidation of an olefin

An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkof less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.

Aqueous hydrogen peroxide solutions and method of making same

A process for the catalytic epoxidation of olefins in the presence of a titanium containing zeolite catalyst and a polar solvent whereby the deactivation of the catalyst upon recycling of the solvent has been considerably reduced. In the process one or more nitrogen containing compounds are introduced at some stage, a solvent stream is recovered, treated to contain less than 50 wppm nitrogen in the form of organic nitrogen compounds and at least a part of it is recycled to the epoxidation step. Also disclosed is a process for the catalytic epoxidation of propene which integrates the treatment and recycle of the solvent into the workup of the reaction mixture.

Process for the epoxidation of olefins

A process for the epoxidation of olefins which includes

A process for the purification of a crude propene oxide containing methanol and acetaldehyde by a continuously operated extractive distillation using an extraction solvent lowering the volatility of methanol and feeding a compound containing an unsubstituted NHgroup capable of reacting with acetaldehyde to a distillation column at a point above the feeding point of the crude propene oxide to give a purified propene oxide containing less than 100 ppm methanol and less than 100 ppm acetaldehyde. There is also disclosed a process for the catalytic epoxidation of propene that includes this purification stage.

Process for the purification of crude propene oxide

A process for the continuous epoxidation of propene with hydrogen peroxide in the presence of a titanium silicalite catalyst and a methanol solvent, wherein the catalyst is periodically regenerated by washing with a methanol solvent at a temperature of at least 100&#xb0; C. and the epoxidation reaction is carried out for periods of more than 300 h between two regeneration steps.

A continuous process for the epoxidation of olefins with hydrogen peroxide in the presence of a heterogeneous catalyst promoting the epoxidation reaction, whereby the aqueous reaction mixture contains i) an olefin; ii) hydrogen peroxide; iii) less than 100 wppm of alkali metals, earth alkali metals, both irrespective whether in ionic, complex or covalently bonded form, bases or cations of bases having a pkof less than 4.5, or combinations thereof; and, iv) at least 100 wppm of bases or cations of bases having a pkof at least 4.5 or combinations thereof, whereby the wppm are based on the total weight of hydrogen peroxide in the reaction mixture.

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Maintal, Germany

Wolfgang Wöll