Patent · US Active

Method for producing a multi-layer catalyst for obtaining phthalic anhydride

US7592293B2 · kind B2 · utility

4Cited by

20References

25Claims

0Family size

Assignee

Sud Chemie, Inc. · US

Inventors

Christian Guckel · Birkenfeld, DE
Harald Dialer · Munich, DE
Marvin Estenfelder · Ebersberg, DE
Werner Pitschi · Bogen, DE

Key dates

Filing date	Aug 29, 2007
Grant date	Sep 22, 2009
Priority date	—
Expiry date	Aug 29, 2027

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB01J2523/00
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

The present invention relates to processes for improving or optimizing a catalyst for the preparation of phthalic anhydride by gas-phase oxidation of o-xylene and/or naphthalene, which comprises the following steps: a) provision of a starting catalyst (C) comprising at least one first catalyst zone located towards the gas inlet and a second catalyst zone located closer to the gas outlet, with the catalyst zones preferably each having an active composition comprising TiO2; b) replacement of part of the first catalyst zone by an upstream zone of a catalyst having a higher activity than the first catalyst zone in order to provide an improved catalyst. Furthermore, an improved catalyst obtainable by this process is described.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.