Basf Aktiengesellschaft

Basf Aktiengsellschaft

Franz-Josef Weiss

Hugo Fuchs

Josef Ritz

Erwin Thomas

Heinz-Walter Schneider

Rudolf Kummer

Gerald Neubauer

Elmar Frommer

Otto-Alfred Grosskinsky

Volker Taglieber

Werner Steigleiter

Wolfgang Hoelderich

Wolfgang Habermann

Peter Hammes

Peter Thoma

Werner Biffar

Luc Guns

Rolf Platz

Peter Magnussen

Otto Hofstadt

Klaus Kartte

Frans Van Deyck

Otto Lemann

Paul Pijl

Benedikt Mangelschots

Roger Verberckt

A hydrogenation catalyst, obtainable by carrying out essentially the following steps:

Hydrogenation catalyst based on a platinum metal partially poisoned with

A process of use of hydrogenation catalyst, obtainable by carrying out essentially the following steps:

Method of use of a hydrogenation catalyst based on a platinum metal

A hydrogenation catalyst, obtainable by carrying out essentially the following steps: (a) treatment of a platinum metal salt with finely divided sulfur followed by (b) reduction of the platinum metal salt to metallic platinum metal.

A process for the preparation of hydroxylammonium salts by the reduction of nitrogen oxide (NO) with hydrogen in dilute aqueous mineral acid in the presence of a suspended platinum catalyst which is partially poisoned with arsenic, at elevated temperature, wherein the catalyst used is one which has been produced by precipitation of metallic platinum from an aqueous solution on to a suspended support in the presence of an oxidic arsenic compound, by means of a reducing agent.

Preparation of hydroxylammonium salts

A platinum-on-graphite catalyst having a platinum content of from 0.01 to 5% w/w, wherein the graphite support has an apparent density of from 1.7 to 2.2 g/ml and the use thereof as a hydrogenation catalyst.

Platinum-on-graphite catalysts

A method of regenerating noble metal catalysyts used for the catalytic reduction of nitrogen oxide with hydrogen, wherein the noble metal catalyst is treated with an aqueous alkaline solution having a pH of more than 9.

Method of regenerating inactive and poisoned platinum catalysts

A platinum-on-graphite catalyst having a platinum content of from 0.01 to 5% w/w, wherein the graphite support has a particle size of from 1 to 600 .mu.m and the following particle size distribution:

Platinum-on-graphite catalysts and the use thereof

Crystalline hydroxylammonium sulfate is prepared by a process which comprises the following steps:

Preparation of crystalline hydroxylammonium sulfate having a low

Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen in dilute aqueous mineral acids at elevated temperature in the presence of suspended supported platinum catalysts obtainable by precipitating metallic platinum from aqueous solutions of platinum salts onto carriers suspended therein by means of reducing agents in the presence of one or more water-soluble substituted or unsubstituted thioureas.

Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid in the presence, in suspension, of a supported platinum catalyst obtainable by precipitating metallic platinum from an aqueous platinum solution onto a support by means of a reducing agent in the presence of an organic chelating agent and partially poisoned with sulfur.

Pure hydroxylammonium salts of fatty acids of 1 to 4 carbon atoms are prepared by reacting hydroxylammonium sulfate and alkali metal salts of fatty acids with 1 to 4 carbon atoms in solution at elevated temperatures and separating off the hydroxylammonium salts of fatty acids of 1 to 4 carbon atoms by

Preparation of pure hydroxylammonium salts of fatty acids of 1 to 4

Aqueous solutions of free hydroxylamine are prepared by a process in which

Preparation of aqueous solutions of free hydroxylamine

Hydroxylamine-O-sulfonic acid is prepared by

Preparation of hydroxylamine-O-sulfonic acid

Wastewaters containing hydroxylamine or its salts are worked up by a process in which the said wastewaters are passed over a strongly acidic ion exchanger, after which a 5-15% strength by weight aqueous sulfuric acid is passed over the said ion exchanger and a solution of hydroxylammonium sulfate in aqueous sulfuric acid is obtained.

Working up wastewaters containing hydroxylamine or its salts

Noble metal catalyst, in particular platinum catalysts, which are applied on carriers and have become poisoned by metals as a result of being used for many years in the preparation of hydroxyl-ammonium salts by catalytic reduction of nitric oxide with hydrogen in an aqueous mineral acid are regenerated by a process in which the metallic impurities are dissolved using nitric acid or aqua regia, the solution is neutralized, the troublesome metals are precipitated from the neutralized solution by means of a selective precipitating reagent, and the purified platinum solution is reused for the preparation of the catalyst. Organic complexing agents which form insoluble or sparingly soluble complexes with the metallic impurities are preferably used as precipitating reagents.

Growing community of inventors

Neuhofen, Germany

Franz-Josef Weiss