Basf Aktiengesellschaft

Basf Aktiengsellschaft

Erwin Thomas

Franz-Josef Weiss

Josef Ritz

Elmar Frommer

Otto-Alfred Grosskinsky

Hugo Fuchs

Guenther Rapp

Wolfgang Habermann

Peter Hammes

Peter Thoma

Gunther Rapp, Deceased

Rolf Muenster

Peter Zehner

Otto Hofstadt

Klaus Kartte

Ruediger Schmitz

Werner Biffar

Frans Van Deyck

Dieter Wolf

Kuerten, Heribert

Kurt Jockers

Guenther Rapp, Deceased

Alfred-Otto Grosskinsky

Paul Pijl

Benedikt Mangelschots

Roger Verberckt

Thomas M Jones

Philip A Cyr

Brodus E Caffall

Gunther Rapp

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.

Preparation of hydroxylammonium salts

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.

Regeneration of inactive and poisoned platinum catalysts

Aqueous solutions of hydroxylamine are prepared from aqueous hydroxylammonium salt solutions by electrodialysis by a method in which the aqueous hydroxylammonium salt solution is fed into the middle zone of an electrolysis cell, which is divided into a cathode zone, an anode zone and a middle zone by means of semipermeable membranes, and is electrolyzed, and the catholyte used is an alkali metal hydroxide solution containing ammonia and/or amines.

Preparation of aqueous hydroxylamine solutions

Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing the lactone of the formula ##STR1## and their preparation.

Stabilized solutions of hydroxylamine or its salts in water or alcohols,

Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing 8-hydroxyquinaldines, and their preparation.

Aqueous solutions of hydroxylammonium carbonate are prepared from aqueous hydroxylammonium salt solutions by electrodialysis by a method in which the aqueous hydroxylammonium salt solution is fed into the middle zone of an electrolysis cell, which is divided into a cathode zone, an anode zone and a middle zone by means of semipermeable membranes, and is electrolyzed, and the catholyte used is an aqueous solution of an ammonium carbonate or an alkali metal carbonate or of one of the corresponding bicarbonates.

Preparation of aqueous solutions of hydroxylammonium carbonate

Stabilized solutions of hydroxylamine or its salts in water or alcohols, containing hydroxyanthraquinones, and their preparation.

Stabilized solutions of hydroxylamine or its salts

Stabilized solutions of hydroxylamine or its salts, containing anthocyans of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen, hydroxyl or C.sub.1 -C.sub.4 -alkoxy and X is an anion of a strong mineral acid, and their preparation.

Nitrous oxide is removed from gases containing hydrogen, nitric oxide and nitrous oxide by a process in which the gases are treated with molecular sieves.

Removal of nitrous oxide from gases containing hydrogen, nitric oxide

Hydroxylammonium salts are manufactured by a process comprising the catalytic reduction of nitric oxide with hydrogen in a dilute aqueous mineral acid in the presence of a suspended platinum catalyst at an elevated temperature, wherein the reaction is carried out in vessels of which the walls consist of conventional copper-containing austenitic chromium-nickel steels which contain from 16 to 28% by weight of chromium, from 32 to 50% by weight of nickel, from 1 to 4% by weight of molybdenum, up to 4% by weight of copper and at most 0.1% by weight of carbon and which in addition contain an amount of titanium which is at least 5 times the amount of carbon but is not more than 1% by weight, or an amount of niobium or tantalum which is at least 8 times the amount of carbon but is not more than 1.5% by weight.

Manufacture of hydroxylammonium salts

An improved process for the continuous preparation of hydroxylammonium salts by catalytic reduction of nitric oxide with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended noble metal catalyst at an elevated temperature in several reaction zones connected in series, wherein the improvement comprises maintaining a pH of &lt;2.0 in the last reaction zone.

Continuous preparation of hydroxylammonium salts

Hydroxylammonium salts are prepared by an improved process, wherein nitric oxide is reduced catalytically with hydrogen in a dilute aqueous solution of a mineral acid in the presence of a suspended supported platinum catalyst and at elevated temperatures, and wherein the improvement comprises avoiding the formation of foam at the surface of the reaction mixture.

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Freinsheim, Germany

Erwin Thomas