Degussa Aktiengesellschaft

Degussa - Huls Ag

Evonik Degussa Gmbh

Matthias Creutz

Rudolf M Wagner

Stefan Nordhoff

J&uuml;rgen Glenneberg

Thomas Haas

Rudolf Vanheertum

J&ouml;rg Sauer

Hubertus Eickhoff

Bernhard Maurer

Stefan Gross

Dieter M&ouml;ller

Rudolf Wagner

The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Continuous hydrogenation process

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

A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H O starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H O concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H O concentration in the crystal layer is increased further.

Process for the concentration of aqueous hydrogen peroxide by crystallization

In carrying out the hydrogenation stage of the anthraquinone process for the preparation of hydrogen peroxide in a hydrogenation reactor on a fixed bed catalyst of a particulate catalyst, the service life of the catalyst is increased in that the working solution comprising the reaction carrier and a gas phase comprising hydrogen, are passed through the hydrogenation reactor from the bottom upwards. The empty tube speed of the working solution is 0.05 to 100 m/h, preferably 10 to 50 m/h.

Process for the preparation of hydrogen peroxide

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Frankfurt-am-Main, Germany

Matthias Creutz