Preparation of hydroxylammonium salts

US5554353A · kind A · utility

Assignee

• BASF SE

Inventors

• Heinz-Walter Schneider · Ludwigshafen, DE
• Axel Wilms · Bad Dürkheim, DE
• R udiger Schmitz · Lambsheim, DE
• Robert Schulz · Lampertheim, DE
• Klaus Michelsen · Hamburg, DE

Key dates

• Filing date: Feb 1, 1995
• Grant date: Sep 10, 1996
• Expiry date: Feb 1, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B21/1418
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for the preparation of hydroxylammonium salts by catalytic reduction of nitrogen monoxide using hydrogen in the presence of a hydrogenation catalyst, comprises (a) in a first step, filtering the reaction mixture obtained after the reaction, giving a solution of essentially hydroxylammonium salt and a filter residue essentially comprising a mixture of hydrogenation catalyst and a solution of essentially hydroxylammonium salt, and (b) in a second step, subjecting the filter residue to a further separation process in order to concentrate the hydrogenation catalyst, giving a mixture having a higher concentration of hydrogenation catalyst than the filter residue and a mixture having a lower concentration of hydrogenation catalyst than the filter residue.