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:
Oct. 14, 2014
Filed:
Jun. 30, 2011
Stefan Altwasser, Wachenheim, DE;
Jürgen Zühlke, Speyer, DE;
Hans-martin Allmann, Neunkirchen, DE;
Frank Rosowski, Mannheim, DE;
Stefan Altwasser, Wachenheim, DE;
Jürgen Zühlke, Speyer, DE;
Hans-Martin Allmann, Neunkirchen, DE;
Frank Rosowski, Mannheim, DE;
BASF SE, , DE;
Abstract
The present invention relates to a multilayer catalyst for preparing phthalic anhydride which has a plurality of catalyst layers arranged in succession in the reaction tube, with the individual catalyst layers having alkali metal contents which decrease in the flow direction. The present invention further relates to a process for the oxidation of naphthalene or o-xylene/naphthalene mixtures over such a multilayer catalyst and the use of such multilayer catalysts for the oxidation of naphthalene or o-xylene/naphthalene mixtures to phthalic anhydride.