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:
Jul. 23, 2013
Filed:
Apr. 07, 2009
Hagen Wilmer, Ludwigshafen, DE;
Jürgen Zühlke, Speyer, DE;
Thomas Lautensack, Birkenau, DE;
Hans-martin Allmann, Neunkirchen, DE;
Frank Rosowski, Mannheim, DE;
Cornelia Katharina Dobner, Ludwigshafen, DE;
Hagen Wilmer, Ludwigshafen, DE;
Jürgen Zühlke, Speyer, DE;
Thomas Lautensack, Birkenau, DE;
Hans-Martin Allmann, Neunkirchen, DE;
Frank Rosowski, Mannheim, DE;
Cornelia Katharina Dobner, Ludwigshafen, DE;
BASF SE, Ludwigshafen, DE;
Abstract
What is described is a process for starting up a gas phase oxidation reactor for oxidation of o-xylene to phthalic anhydride, said reactor comprising at least one catalyst layer and being temperature-controllable by means of a heat carrier medium, wherein a) the catalyst layer is interrupted by a moderator layer which is less catalytically active than the catalyst layer or is catalytically inactive, b) a gas stream is passed through the reactor with an initial loading of o-xylene and at an initial temperature of the heat transfer medium, c) the loading of the gas stream is increased to a target loading and, in parallel, the temperature of the heat transfer medium is lowered to an operating temperature. The introduction of the moderator layer allows the loading to be increased more rapidly and the startup time to be shortened.