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:
Aug. 05, 2014
Filed:
Sep. 08, 2010
Hans-jörg Wölk, Rosenheim, DE;
Gerhard Mestl, München, DE;
Hans-Jörg Wölk, Rosenheim, DE;
Gerhard Mestl, München, DE;
Süd-Chemie IP GmbH & Co. KG, Munich, DE;
Abstract
A method for producing phthalic anhydride by catalytic gas-phase oxidation of o-xylene and/or naphthalene, carried out by means of a catalyst arrangement which has a first catalyst layer at the gas inlet side and at least one second catalyst layer after the first catalyst layer in the gas flow direction with different catalytic activity, wherein when the gas-phase oxidation is being carried out a lower maximum temperature is formed in the first catalyst layer than in the second catalyst layer. Furthermore, a method for producing the catalyst arrangement, as well as the catalyst arrangement itself.