Degussa Aktiengesellschaft

Degussa - Huls Ag

Birgit Bertsch-Frank

Thomas Lieser

Martin Bewersdorf

Klaus Mueller

Ina Hemme

Claas-Juergen Klasen

Torsten Balduf

Lothar Kaiser

Rainer Kohlen

Werner Wildner

Wolfgang Lortz

Harald Jakob

Stipan Katusic

Georg Markowz

Friedrich Bittner

Rudiger Schutte

Alexander Ruhs

Claas-Jurgen Klasen

Ralph Overdick

Rüdiger Schütte

Peter Schubert

Michael Scheibe

Catrin Becker-Balfanz

Jürgen Rollmann

Petra Look-Herber

J&uuml;rgen Rollmann

Juergen Rollmann

Catrin Becker

Lukas Von Hoppel

Jurgen Rollmann

Axel Duker

Gert Rossler

Joerg Herzig

Wolfgang Zikofsky

Klaus Muller

Reactions between at least two fluid reactants are performed in a reactor comprising wall elements (), slot-shaped reaction spaces () and cavities () for conducting a fluid heat-carrier through. Depending on the process and throughput, a modular structural design is chosen wherein an arbitrary number of wall elements () are assembled to a right-parallelepipedal block (), the reaction spaces () are formed between lateral surfaces () of right-parallelepipedal wall elements (), the reactants are introduced into the reaction spaces () from edge regions of one side of the block () and are conducted through the reaction spaces () in parallel flows and the fluid heat-carrier is conducted through the tubular cavities () extending in the interior of the wall elements ().

Process and device for carrying out reactions in reactor with slot-shaped reaction spaces

The invention relates to a process for the production, by fluid-bed spray granulation, of granular sodium percarbonate having a low TAM value. According to the invention, in the fluid-bed spray granulation, an Mg compound in a quantity of 50 to 2,000 ppm, in particular 100 to 1,000 ppm, or/and a complexing agent from among the hydroxycarboxylic acids, aminocarboxylic acids, aminophosphonic acids and phosphonocarboxylic acids, hydroxyphosphonic acids and their alkali metal salts, ammonium salts or Mg salts, in a quantity of 50 to 2,000 ppm, in particular 200 to 1,000 ppm, are added as stabilisers to the soda solution and/or HOsolution. Preferably a combination of an Mg compound in a quantity of 100 to 1,000 ppm Mgand waterglass in a quantity of 0.1 to 1 wt. %, in particular 0.1 to 0.5 wt. %, is used, and in this case granules having a TAM value of about or below 6 &#x3bc;W/g and simultaneously a short dissolving time, are obtainable.

Granular sodium carbonate obtained by fluid-bed spray granulation and a process for its production

A process for the direct synthesis of hydrogen peroxide from hydrogen and oxygen is carried out in the presence of a noble metal catalyst. The selectivity for H and/or the maximum H O concentration can be increased by using a catalyst of palladium or at least two metals selected from Group VIII and Group I of the Periodic Table of Elements, which catalyst has been produced by spray pyrolysis or flame pyrolysis.

Process for producing hydrogen peroxide by direct synthesis

The invention relates to a fluidized bed reactor for the continuous production of fluidized bed granules. The reactor is characterized by a discharge device designed as a siphon pipe or siphon weir. The fluidized bed reactor permits a trouble-free continuous operation of the fluidized bed stage and of a connected, continuous subsequent stage. A preferred fluidized bed reactor comprises two chambers that are in communication via the discharge device according to the invention.

Fluidized bed reactor and a process of using the same

A process for the preparation of coated peroxygen compounds, in particular sodium percarbonate, by fluidized bed coating. By using a fluidized bed reactor with a radial inflow base, the passage openings of which allow the fluidized bed gas to emerge in the region of the opening at an angle of less than 35&deg;, measured with respect to the horizontal, in the form of directed part streams, and in which are arranged spray nozzles, the pulse of which points in the same direction as the pulse of the fluidizing gas, it is possible to obtain products with an increased active oxygen stability. A circular reactor, the inflow base of which has lamellae overlapping like turbine blades and nozzles aligned in the direction of rotation of the fluidized bed is preferred.

Process for preparation of coated peroxygen compounds

An aqueous solution of hydrogen peroxide is produced by direct synthesis from hydrogen and oxygen in the presence of a heterogeneous catalyst. According to the invention, a gas mixture comprising H.sub.2 and O.sub.2, essentially saturated or supersaturated with water (=containing fog) is fed into a reactor containing the catalyst. The volume ratio of the gas mixture fed in (standard liters per hour) to liquid removed (liters per hour) is adjusted to a value equal to or greater than 15,000, especially 20,000 to 50,000, and the gas mixture leaving the reactor is recycled after replenishment with H.sub.2, O.sub.2, and H.sub.2 O vapor. Solutions with high H.sub.2 O.sub.2 concentration can be obtained according to the invention without additional concentration.

Coated sodium percarbonate particles contain, in the coating, sodium carbonate and also one or more magnesium compounds, preferably magnesium sulfate, optionally in a partially hydrated form, in a single layer or in separate layers in the coating. Preferred coated sodium percarbonate particles contain two layers. Particles are prepared by spraying aqueous solutions containing the coating components onto sodium percarbonate in a fluidized bed with simultaneous evaporation of the water. The particles are suitable for use in detergents, bleaches and cleansing agents.

Coated sodium percarbonate particles, a process for their preparation

A process for reducing dissolution time in the production of sodium percarbonate particles containing an alkali metal silicate as stabilizer by fluidized bed spray granulation and/or by coating sodium percarbonate particles with a coating containing an alkali metal silicate, wherein a solution containing alkali metal silicate is sprayed during production and/or coating which contains alkali metal silicate having a modulus in the range from less than 3 to greater than 1. Sodium percarbonate produced by fluidized bed spray granulation is distinguished by elevated Oa stability and short dissolution times and may thus readily be used in detergents and cleaning products containing silicate builders.

Process for reducing dissolution time in the production and/or coating

Coated sodium percarbonate particles, a process for their production and

Method for the preparation of stabilized sodium percarbonate

Sodium percarbonate is produced by means of fluidized bed granulation. The process includes spraying an aqueous sodium carbonate solution and a hydrogen peroxide solution onto nuclei in a fluidized bed and evaporating the water. In the process of the invention, it is not necessary to use a phosphorus-containing crystallization inhibitor in order to avoid cloggings and incrustations in and on the nozzle. This is accomplished by spraying the solutions through separate channels in a single ternary atomizer nozzle, to provide external mixing of the solutions with respect to the nozzle.

Method for producing granulated sodium percarbonate

The invention relates to sodium perborate hydrate granulates and a method for producing sodium perborate hydrate granulates with an available oxygen content of 14 to 18% by weight, especially 15 to 16% by weight; an abrasion index according to ISO test 5937 of not more than 10%; with a rate of dissolution of below 1.5 minutes, preferably below 1.0 minutes (for 1 gram of the granulate in 500 cm.sup.3 water, at 15.degree. C.); and with a bulk weight in the range of 0.6 to 1.2 kg/dm.sup.3. The sodium perborate hydrate granulate can be produced by compacting spray-dried, essentially amorphous sodium perborate hydrate starting material which exhibits a bulk weight below that of the granulate product, and a particle size of 90% less than 100 micrometers. The hydrate starting material is further characterized in that it loses 0.2 to 2.0% of its weight when stored at 60.degree. C. and 100 Pa for 30 minutes. The starting material is compacted between rollers at a contact pressure of 5.times.10 to 2.times.10.sup.4 N/cm, and the resultant product is comminuted and the granulate is sieved according to particle size. The compacted granulate particles may be rounded off by means of a mechanical stressing prior to the sieving step. This method produces granulates with the above-mentioned characteristics which are desired in the market. The granulates are produced in a simple manner, without thermal stressing of the perborate.

Method for the production of sodium perborate hydrate granulates

Previously known peroxymonosulfate solutions exhibit an unsatisfactory storage stability and/or can only be used with technical limitations. According to the invention, storage-stable, aqueous sodium peroxymonosulfate solutions can be prepared with a content of 5% to 50% by weight NaHSO.sub.5 in an economic manner by means of the partial neutralization of a solution containing sulfuric acid and Caro's acid if a such a solution containing H.sub.2 SO.sub.4 and H.sub.2 SO.sub.5 is added which contains less than 3 parts by weight hydrogen peroxide per 100 parts by weight Caro's acid and the partial neutralization is carried out up to an equivalent proportion of total SO.sub.3 to sodium ions in a range of 1 to 1 up to 1 to 1.3 and if the solution is diluted or concentrated as required.

Method of preparing storage-stable aqueous sodium peroxymonsulfate

The spray drying of a solution containing hydrogen peroxide and sodium metaborate to obtain primary particles which are immediately conveyed after leaving the drying zone to a granulating device and are then granulated in the presence of free and/or perborate water of crystallization. The granulated materials are dried, if necessary. The generally amorphous primary particles are converted into granulated materials with at least partially crystalline structure and significantly improved shelf life. The work is performed with advantage in a spray dryer with integrated fluid bed or in a compressing granulating device. The method is suitable for preparing perborate granulated materials with an active oxygen content of over 10% by weight, especially perborate monohydrate granular materials with 14 to 16% by weight active oxygen. A rapidly dissolving product is produced with an acceptable apparent weight for ease in packaging.

High active oxygen content granulated sodium perborate product and

The spray drying of a solution containing hydrogen peroxide and sodium metaborate to obtain primary particles which are immediately conveyed after leaving the drying zone to a granulating device and are then granulated in the presence of free and/or perborate water of crystallization. The granulated materials are dried, if necessary. The generally amorphous primary particles are converted into granulated materials with at least partially crystalline structure and significantly improved shelf life. The work is performed with advantage in a spray dryer with integrated fluid bed or in a compressing granulating device. The method is suitable for preparing perborate granulated materials with over 10% by wt., especially perborate monohydrate granular materials with 14-16% by wt. active oxygen.

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Rheinfelden, Germany

Birgit Bertsch-Frank