Degussa Aktiengesellschaft

Evonik Stockhausen Gmbh

Uhde Gmbh

Evonik Degussa Gmbh

Stefan Gross

Stefan Nordhoff

Torsten Balduf

Axel Kobus

Roland Fornika

Guenther Bub

Hans-Rolf Lausch

Georg Markowz

Rudolf M Wagner

Olaf Von Morstein

Ruediger Schuette

Steffen Schirrmeister

Elias Johannes Klemm

Johannes Ehrlich

Matthias Creutz

Johannes Albrecht

Armin Lange De Oliveira

Rudolf Wagner

The invention relates to a superabsorbent polymer that includes a (meth)acrylic acid made by a process that comprises the following process steps: a) (meth)acrylic acid is crystallized out from a mother liquor; b) crystallized (meth)acrylic acid is separated from the mother liquor; c) at least part of the separated (meth)acrylic acid crystals are melted; d) the melted part is at least partially recycled to the step a) or step b). The superabsorbent polymer according to the present invention includes an process to make (meth)acrylic acid, the apparatus suitable for implementing the process, and the use of the apparatus for the production of (meth)acrylic acid characterized by a high purity of the thereby obtainable (meth)acrylic acid as well as by a high efficiency with regard to the achievable yield and necessary energy requirement, thereby providing an improved superabsorbent polymer.

Superabsorbent polymer made from acrylic acid

The invention relates to a process for the purification of (meth)acrylic acid in a process stage that comprises the following process steps: a) (meth)acrylic acid is crystallized out from a mother liquor; b) crystallized (meth)acrylic acid is separated from the mother liquor; c) at least part of the separated (meth)acrylic acid crystals are melted; d) the melted part is at least partially recycled to the step a) or step b). The process according to the invention, the apparatus suitable for implementing the process, and the use of the apparatus according to the invention for the production of (meth)acrylic acid are characterized by a high purity of the thereby obtainable (meth)acrylic acid as well as by a high efficiency with regard to the achievable yield and necessary energy requirement.

Continuous process for the production and purification of acrylic acid

A modular construction micro-reactor with parallel microchannels on fluid guide plates for chemical reactions, but not for evaporation purposes is known. A modular construction falling film evaporator is disclosed, comprising a stack of alternate gap-like evaporation chambers and sheet-like evaporator modules with an assembly of parallel microchannels, whereby the evaporation chambers are open above and/or below across the whole width of the module and the stack is arranged in a container. The falling film evaporator is used in a method for obtaining a gaseous phase from a liquid medium on a technical scale and is suitable for the concentration of thermolabile solutions and rapidly adjustable production of a gas stream.

Method for obtaining a gaseous phase from a liquid medium and device for carrying out the same

A process for the continuous preparation of very highly concentrated hydrogen peroxide having a content of greater than 80 wt.%, especially over 98 wt.%, by suspension crystallization and after-treatment of the H O crystals. The after-treatment takes the form of countercurrent washing in a hydraulic or mechanical washing column with a packed crystal bed. Hydrogen peroxide is disclosed having a concentration of from 99.9 to 100 wt.% and a content of TOC, nitrate, phosphate, nickel and tin of in each case less than 4 mg/l.

Crystallization process for producing highly concentrated hydrogen peroxide

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Langenselbold, Germany

Stefan Gross