Evonik Stockhausen Gmbh

Evonik Degussa Gmbh

Huels Aktiengesellschaft

Stockhausen Gmbh

Günther Bub

Jürgen Mosler

Andreas Sabbagh

Franz-Felix Kuppinger

Guido Stochniol

Torsten Balduf

Axel Hengstermann

Franck Furno

Arndt Selbach

Markus Winterberg

Jörg Leistner

Dietrich Maschmeyer

Horst-Werner Zanthoff

Udo Knippenberg

Jörg Sauer

Roland Fornika

Jürgen Kohn

Thorsten Schwärtzke

Günter Latoschinski

Stefan Nordhoff

Axel Kobus

Manfred Zur Hausen

Werner Fuhrmann

Thomas Rathke

Dennis Thong

Matthias Peuckert

Michael Bernd Fricke

Dr Jörg Leistner

Hans-Rolf Lausch

Stephan Gross

In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Superabsorbent polymers and methods of making the same

The present invention relates to a process for the production of polymers, such as water-absorbing polymer structures, by radical polymerization of acrylic acid, whereby the acrylic acid has been obtained by a synthesis process which comprises as a process step the splitting of an organic material by means of an enzyme or at least one component of an enzyme. The invention also relates to the water-absorbing polymers obtainable by this process, water-absorbing polymers which are based to at least about 25 wt % upon partially neutralized acrylic acid, a composite, a process for the production of a composite, the composite obtainable by this production, the use of acrylic acid in the production of polymers, preferably in the production of water-absorbing polymer structures, a device for the production of acrylic acid, and a process for the production of acrylic acid.

Water-absorbent polymer structures based on renewable resources and method for producing said structures

The invention relates to producing a superabsorbent polymer comprising (I) producing a (meth)acrylic acid comprising the steps of (a) synthesizing a crude (meth)acrylic acid phase; (b) distillatively working-up the crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase comprising (meth)acrylic acid dimers and/or (meth)acrylic acid oligomers; (c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain a (meth)acrylic acid-comprising a low boiling phase and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; (d) separating at least a part of the (meth)acrylic acid from the low boiling phase by forming crystals to obtain a pure (meth)acrylic acid, and a residue; (II) polymerizing a monomer phase comprising the pure (meth)acrylic acid to obtain a polymer phase; and (III) working-up the polymer phase to obtain the polymer.

The present invention relates to a process for producing a superabsorbent a polymer comprises (I) producing a pure (meth)acrylic acid comprising the steps of (a) synthesizing a crude (meth)acrylic acid phase; (b) distillatively working-up the crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase comprising (meth)acrylic acid dimers or (meth)acrylic acid oligomers or both; (c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain a (meth)acrylic acid-comprising low boiling phase and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; (d) separating at least a part of the (meth)acrylic acid from the low boiling phase to obtain a pure (meth)acrylic acid, and a residue; (II) polymerizing a monomer phase comprising the pure (meth)acrylic acid to obtain a polymer phase; and (III) working-up the polymer phase to obtain the polymer.

In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a) provision of a fluid Fhaving a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a) dehydration of said hydroxypropionic acid to give a fluid Fcontaining acrylic acid; and (a) purification of said fluid Fto give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

The present invention relates to superabsorbent polymer comprising acrylic acid made by the process comprising the steps of heating an aqueous glycerine solution to form glycerine; transporting the glycerine to the dehydration reactor; dehydrating the glycerine to an acrolein-comprising dehydration product; gas phase oxidating of the acrolein-comprising dehydration product to obtain an acrylic acid-comprising monomer gas; bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; working-up the quench phase to obtain an acrylic acid-comprising monomer phase; and polymerizing the acrylic acid-comprising monomer phase; wherein a plurality of gas bubbles is generated and wherein the dehydration occurs at least partially in the liquid phase. The superabsorbent polymer has certain properties for biodegradability and sustainability. Further, at least about 25% of the acrylic acid is based on glycerine. The superabsorbent polymer has a sustainability factor of at least about 80%.

Water-absorbing polymer structures based on renewable raw materials and process for their production by dehydration

The invention relates to a process for the preparation of acrylic acid and a process for the preparation of polyacrylic acid comprising the process steps: (a1) preparation of 3-hydroxypropionic acid from a biological material to give a fluid, in particular aqueous, phase containing 3-hydroxypropionic acid; (a2) dehydration of the 3-hydroxypropionic acid to give a fluid, in particular aqueous, solution containing acrylic acid; (a3) purification of the solution containing acrylic acid by a suspension crystallization or a layer crystallization to give a purified phase; and corresponding devices for carrying out these processes, and acrylic acid and polyacrylates. The invention is distinguished in that acrylic acid and polyacrylates can thereby be prepared efficiently, inexpensively, and sustainably with simple means and with a high purity on the basis of regenerable raw materials.

Process for preparing acrylic acid purified by crystallization from hydroxypropionic acid and apparatus therefore

A process for production of (meth)acrylic acid is disclosed. The process includes synthesizing and distillatively working-up a crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase including (meth)acrylic acid dimers and/or (meth)acrylic acid oligomers. At least a part of the (meth)acrylic acid dimers and/or of the (meth)acrylic acid oligomers from the dimer phase is split to obtain a (meth)acrylic acid including a low-boiling phase and a high-boiling phase including less (meth)acrylic acid than the low-boiling phase. At least a part of the (meth)acrylic acid from the low-boiling phase is separated by forming of one or more crystals to obtain a pure (meth)acrylic acid and a residue. Also disclosed is a device for production of (meth)acrylic acid, a process for production of a polymer as well as chemical products based on or including (meth)acrylic acid or a polymer as well as the use of (meth)acrylic acid or polymers in chemical products.

Process for production of (meth)acrylic acid with high boiling fraction work-up by means of crystallization

The present invention relates to a process for production of acrylic acid, comprising the steps of a) dehydration of glycerine to an acrolein-comprising dehydration product; b) gas phase oxidation of the dehydration product to obtain an acrylic acid-comprising monomer gas; c) bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; and d) work-up of the quench phase to obtain an acrylic acid-comprising monomer phase; whereby, during the dehydration a liquid phase a1 and a gas phase a2 is present, whereby in the liquid phase a1 a plurality of gas bubbles is generated, as well as a process for production of polymers by polymerization of acrylic acid, preferably for production of water-absorbing polymers, the water-absorbing polymers obtainable by this process, a composite, a process for production of a composite, the composite obtainable by this process, and further chemical products.

Acrylic acid and water-absorbing polymer structures based on renewable raw materials and process for their production by dehydration

The present invention relates to processes for purifying a composition containing (meth)acrylic acid, at least one impurity and water, wherein the composition has a water content in the range of 0.55 to 90, based on the composition, to form a purified phase containing (meth)acrylic acid and at least one impurity, wherein, in the purified phase, the quantity of at least one impurity is less than 7% by weight, based on (meth)acrylic acid in the purified phase.

(Meth)acrylic acid crystal and process for producing aqueous (meth)acrylic acid

The present invention relates to a process for the production of acrylic acid (AA) comprising the steps wherein: a) a 1st gas mixture comprising propylene, oxygen, an inert gas and steam is subjected to a 1st catalytic oxidation reaction stage thereby converting the propylene in the presence of a catalyst mainly into acrolein being contained in a 2nd gas mixture from said 1st catalytic oxidation reaction, b) said 2nd gas mixture from the 1st catalytic oxidation reaction stage is subjected to a 2nd catalytic oxidation reaction stage thereby converting the acrolein in the presence of a catalyst mainly into AA, being contained in a product gas, c) said product gas is subjected to a quench tower, wherein said AA is recovered as an aqueous solution comprising said AA being contained in the process water, wherein a process vent gas is obtained at the top of said quench tower, wherein, said 1st gas mixture has a steam/propylene ratio of &#x3e;0.3 and &#x3c;2 and, the amount of said process water is less or equal to the amount of water in said aqueous solution withdrawn from the quench tower.

Process for the production of acrylic acid

A method of producing aliphatic and cycloaliphatic diols by catalytic hydrogenation of dicarboxylic acid esters by the use of a copper chromite catalyst in which the copper content (calculated as CuO) is 40-47 wt. %, and the chromium content (calculated as Cr.sub.2 O.sub.3) is 40-47 wt. %, and barium is also present in the amount of up to 10 wt. % (calculated as BaO) under mild temperature and pressure conditions is disclosed. The method produces diols without the formation of high boiling materials and does not require purification of the product diols by overhead distillation.

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Marl, Germany

Günther Bub