Evonik Roehm Gmbh

Rohm Gmbh

Evonik Rohm Gmbh

Rudolf Burghardt

Steffen Krill

Torsten Balduf

Alexander Lygin

Matthias Groemping

Martin Koestner

Gerhard Koelbl

Eduard Rundal

Florian Zschunke

Daniel Helmut König

Torsten Panak

Andreas Tepperis

Matthias Grömping

Gerhard Kölbl

Frederik Gluth

Melanie Raczek

Reed Zhao

Martin KÖSTNER

Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Continuous process for preparing methacrolein

A process and a preparation plant prepares methacrolein from formaldehyde and propionaldehyde, in presence of water and a homogeneous catalyst based at least on an acid and a base. A reaction mixture is introduced into a methacrolein workup plant and separated in a first distillation column, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed and, in a first phase separator, the organic phase and the aqueous phase of the condensate are separated from one another. The aqueous phase is introduced into a second distillation column, that is not part of the methacrolein workup plant, and is separated into a third distillation mixture in a gas phase at the top and a fourth distillation mixture at the bottom. The third distillation mixture is introduced into the methacrolein workup plant.

Process for preparing methacrolein from formaldehyde and propionaldehyde and preparation plant for the purpose

A process and a preparation plant can prepare methacrolein from formaldehyde and propionaldehyde in the presence of a homogeneous catalyst mixture based at least on an acid and a base. For a good workup of the reaction mixture leaving the reactor, with a good energy balance and where the process has simplified apparatus implementation, the liquid reaction mixture under pressure is expanded in an expansion vessel and separated into a first expansion mixture in a gas phase and a second expansion mixture in a liquid phase. The first expansion mixture is condensed in a first condenser and the second expansion mixture is introduced into a first distillation column and separated therein, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed in the first condenser.

The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Method for producing methylmethacrylate

The present invention relates to a process for producing methyl methacrylate, comprising the following steps:

The present invention relates to an optimized process for preparing methacrylic acid, wherein methacrolein is prepared in a first stage from propionaldehyde and formaldehyde by means of a Mannich reaction and oxidized in a second stage to methacrylic acid. More particularly, the present invention relates to the reduction in the amounts of catalyst to be used in the first stage, especially to the reduction in the amounts of acid to be used here, by virtue of the additional installation of recycling streams suitable for the purpose.

Optimized process for preparing methacrylic acid

The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavorings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

Optimized method for producing methacrolein

The present invention relates to a catalytic continuous process for producing methyl methacrylate, said process comprising the step of reacting methacrolein with oxygen and methanol in the presence of a heterogeneous noble-metal-containing catalyst in an oxidative esterification reaction to give methyl methacrylate, characterized in that the stationary concentration of the starting material methacrolein is equal to or less than 12% by weight based on the total weight of the reaction mixture in the reactor, and the ratio F between the total liquid volume within the reactor expressed in liters divided by the total weight of catalyst in the reactor expressed in kilograms is equal to or less than 4.

Process for producing methyl methacrylate

The present invention relates to the oxidative combustion of amine-containing wastewaters, especially in a process for preparing methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for preparation of methacrylic acid, methyl methacrylate, or else of active ingredients, odorants or flavorings. More particularly, the present invention relates to an oxidative combustion of the amine-containing wastewaters with only low nitrogen oxide formation.

Recirculation and disposal of aqueous catalyst solutions in amine catalytic processes

The invention relates to a process for preparation of at least one of methacrylic acid and a methacrylic acid ester, comprising the process stepsgas phase oxidation of at least one Ccompound, quenching of the reaction phase, separation and purification of the obtained methacrylic acid and optionally esterification, wherein the Ccompound is a methacrolein comprising mixture, originating from at least two different methacrolein sources, a first methacrolein source being a feed stream obtained by the heterogeneously catalyzed gas phase oxidation of isobutylene or tert-butyl alcohol or isobutylaldehyde or a mixture of two or more thereof, a second methacrolein source being a feed stream obtained by the reaction of propionaldehyde with a Cextending agent, preferably formaldehyde, and where said methacrolein can be obtained either completely from the first methacrolein source, or completely from the second methacrolein source or from any mixture of both.

Process for preparation of methacrylic acid and methacrylic acid esters

The present invention relates to a process for preparing methyl methacrylate by a direct oxidative esterification of methacrolein with oxygen and methanol, which is conducted in the liquid phase at a pressure of 2 to 100 bar with a gold catalyst. According to the invention, the liquid phase is withdrawn continuously from the reactor and optionally enriched with oxygenous gas, the pH, after the withdrawal, is adjusted to a pH between 5 and 9 by means of addition of a basic solution and this liquid phase is conducted back into the reactor again to an extent of at least 50%.

Process for preparing unsaturated esters proceeding from aldehydes by direct oxidative esterification

The present invention concerns regulating the water content in a process for production of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for production of methacrylic acid, methyl methacrylate or else of active, aroma or flavor chemicals. The present invention is particularly concerned with regulating the water content in a process for production of methacrolein from formaldehyde and propionaldehyde via a Mannich condensation.

Method of regulating the water content in a continuous method for producing methacrolein

The present invention relates to a process for preparing methyl methacrylate by direct oxidative esterification of methacrolein and the preparation of methacrolein. It is a feature of this novel process that it was possible to distinctly increase the yield and the efficiency of the process compared to the prior art through a sequence of different distillation steps.

Growing community of inventors

Darmstadt, Germany

Rudolf Burghardt