Degussa Aktiengesellschaft

Degussa - Huls Ag

J&uuml;rgen Glenneberg

Rudolf M Wagner

Matthias Creutz

Hubert Angert

Thomas Haas

Rudolf Vanheertum

Stefan Nordhoff

J&ouml;rg Sauer

Holger Sauerstein

Eugen Staab

Gustaf Goor

Dieter M&ouml;ller

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

A method for producing 2-(4-methyl-3-pentenyl)anthraquinone (IHEAQ) that includes a Diels-Alder addition of naphtho-1,4-quinone and myrcene and an oxidation of the resulting adduct. The oxidation step is carried out in the presence of a solvent mixture that contains a polar and a nonpolar solvent. The oxidation takes place with air or an O -containing gas in the presence of a combination of a strong inorganic base and an organic, especially a nitrogen-containing base. The method leads to a higher space-time yield and higher product purity.

Method for producing 2-(4-methyl-3-pentenyl) anthraquinone

A cyclic anthraquinone process for producing hydrogen peroxide using at least two differently substituted 2-alkylanthraquinones and/or their tetrahydro derivatives. The working solution to be used contains (i) at least one reaction carrier from the series 2-(4-methyl-3-pentenyl) anthraquinone (IHEAQ), 2-(4-methylpentyl) anthraquinone (IHAQ) and their di- and tetrahydro derivatives such as, in particular 2-(4-methylpentyl)-&bgr;-tetrahydroanthraquinone (THIHAQ), and (ii) at least one reaction carrier from the series of the 2-(C - to C )-alkylanthraquinones, especially 2-ethylanthraquinone (EAQ), and their tetrahydro derivatives. The reaction carriers according to (i) make up 5 to 95 molar %, especially 20 to 50 molar % of all reaction carrier. The method is distinguished by greater H O capacity, improved hydrogenation kinetics and lesser susceptibility to disturbances. A method for making THIHAQ is also disclosed.

Method of producing hydrogen peroxide and reaction promoters therefor

Growing community of inventors

Offenbach, Germany

Jürgen Glenneberg

Growing community of inventors

Offenbach, Germany

J&uuml;rgen Glenneberg

Jürgen Glenneberg