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. 19, 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 shut down by first stopping the amine stream and still maintaining the phosgene stream. After a period of time which corresponds to at least 10 times the residence time of phosgene () in the main parts of the gas phase phosgenation plant () in regular operation, calculated from the time at which the amine inflow has been completely stopped, the feed of phosgene is also stopped. An inert gas stream () is maintained through the amine and phosgene feeding devices and through all the other essential parts of the gas phase phosgenation plant () during the shutdown.