Degussa Aktiengesellschaft

Degussa - Huls Ag

Evonik Degussa Gmbh

Uhde Gmbh

Thyssenkrupp Industrial Solutions Ag

Hubertus Eickhoff

Thomas Haas

Guido Stochniol

Willi Hofen

Georg Thiele

Norbert Ullrich

Wolfgang Wöll

Rudiger Schutte

Claudia Brasse

Marc Brendel

Werner Pohl

Bernhard Maurer

Matthias Creutz

Wedigo Von Wedel

John Tarabocchia

Percy Kampeis

Ernst-Robert Barenschee

R&uuml;diger Sch&uuml;tte

Manfred Weck

Ulrich Schelbert

José Berges

Wegido Von Wedel

Wolfgang Woell

Gerald Moroff

Claudia Wallert

Eduardo Arevalo

Florian Lode

The invention is directed to a process for concentrating aqueous hydrogen peroxide solution to give at least two hydrogen peroxide streams of different concentration in an apparatus which includes a preevaporator (), a distillation column () and a vapour compressor (). The aqueous hydrogen peroxide solution to be concentrated () is continuously fed into the preevaporator; vapour () produced by evaporation in the preevaporator is fed to the distillation column; bottom product () obtained in the preevaporator is withdrawn as a first concentrated hydrogen peroxide stream (); vapour () produced in the distillation column is withdrawn from the distillation column at the top of the column, compressed by the vapour compressor and used for heating the preevaporator; and the bottom product () obtained in the distillation column is withdrawn as a second concentrated hydrogen peroxide stream (); Concentrated hydrogen peroxide solutions having differing concentrations in the range from 50 to 70% by weight of hydrogen peroxide can be produced at the same time in a freely selectable ratio by feeding part of the bottom product obtained in the preevaporator in liquid form to the distillation column.

Method for concentrating an aqueous hydrogen peroxide solution

A process for the epoxidation of olefins which includes

Process for the epoxidation of olefins

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

The invention relates to a process for carrying out gas-liquid reactions in a continuous flow reactor having several reactor chambers arranged parallel to one another, open in the direction of flow. The space-time yield can be increased in that a reactor is used with at least three chambers, the ratio of chamber width b to slit width s of which is, on average, greater than 3 and the slit width s of which is in the range of 5 to 100 mm. Preferably, s is in the range of 5 to 50 mm and s/b in the range of 5 to 100. The continuous flow reactor according to the invention with the at least three reactor chambers and the above ratio s/b is preferably tubular and contains one or more plate stacks.

Process for carrying out gas-liquid reactions and continuous flow reactor for this purpose

Bubble column and the use thereof

Disclosed is a process for the degradation of highly toxic halogenated organic compounds, in particular polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF), contained in gases containing no SO.sub.2 by oxidation using preferably hydrogen peroxide. The SO.sub.2 -free gas is passed, in the presence of hydrogen peroxide, over a substantially inorganic solid contact catalyst, in particular pyrogenic or precipitated silica or aluminum silicate. A residual PCDD/PCDF content of below 0.1 ng TE/Nm.sup.3 may be achieved in the thus treated gas; the highly toxic compounds are oxidized on the solid contact catalyst.

Process for the degradation of highly toxic halogenated organic

A process is described for the removal of nitrogen oxides from waste gases with the recovery of nitric acid or a nitrate solution. The waste gas is reacted with hydrogen peroxide in an amount appropriate to the desired degree of removal of nitrogen oxides, on a catalyst, at a temperature of less than 800.degree. C., preferably in the range of 20.degree. to 100.degree. C., to give the valuable product, nitric acid or a nitrate solution. This may be done in accordance with the invention by bringing the hydrogen peroxide as a solution, i.e., in the liquid phase, into contact with the catalyst through which the waste gas is flowing. The reaction product is either utilized in a gaseous form or processed to nitric acid or a nitrate solution. Alternatively, the hydrogen peroxide may be introduced in a gaseous form, using a honeycombed catalyst, and wherein the hydrogen peroxide is present in at least one half of the stoichiometrically determined amount. Regardless of whether the hydrogen peroxide is introduced in a liquid or vapor form, the resulting nitric acid solution may be scrubbed, preferably with a nitrate salt solution, to provide the concentrated product.

Process for the oxidative purification of waste gases containing

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Alzenau, Germany

Hubertus Eickhoff