The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 12, 2017
Filed:
Mar. 24, 2015
Covestro Deutschland Ag, Leverkusen, DE;
Thomas Knauf, Dormagen, DE;
Wolfgang Lorenz, Dormagen, DE;
Friedhelm Steffens, Leverkusen, DE;
Rainer Bruns, Bergisch Gladbach, DE;
Wolfgang Taube, Neuss, DE;
Covestro Deutschland AG, Leverkusen, DE;
Abstract
This invention relates to a process for operating a gas phase phosgenation plant () to form an isocyanate () by reacting an amine () with phosgene (), in which the gas phase phosgenation plant is started up by first charging the plant with phosgene. At the same time as, or after the first charge of phosgene, the amine supply devices are rendered inert using a hot inert gas stream (). Then, amine is admixed for the first time. In this way and by maintaining a pressure drop in the amine and phosgene devices to the mixing zone, the back mixing of phosgene into the amine-containing reactant stream during start-up is prevented.