Process for providing hydrogen chloride for chemical reactions

US10815193B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Jan Busch · Düsseldorf, DE
• Jürgen Arras · Itzehoe, DE
• Christian Steffens

Key dates

• Filing date: Jun 27, 2016
• Grant date: Oct 27, 2020
• Expiry date: Jan 31, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/80
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention relates to an improved process for making available the coproduct hydrogen chloride obtained in the preparation of an isocyanate by phosgenation of the corresponding amine for a desired subsequent use (i.e. a chemical reaction), in which part of the total hydrogen chloride obtained is isolated in gaseous form at a pressure which is higher than the pressure desired for the subsequent use of the hydrogen chloride by lowering the pressure of the crude product from the phosgenation and the remaining part of the total hydrogen chloride obtained is separated off at a pressure lower than that desired for the subsequent use from the liquid crude product from the phosgenation remaining after lowering of the pressure and is subsequently compressed to a pressure which is higher than that desired for the subsequent use, and in which the two hydrogen chloride streams obtained in this way are, preferably together after having been combined, purified so as to give a purified hydrogen chloride at a pressure which is higher than the pressure desired for the subsequent use.