Patent · US Expired

Use of a multi-layer catalyst for producing phthalic anhydride

US7615513B2 · kind B2 · utility

8Cited by

20References

25Claims

0Family size

Assignee

Süd-Chemie AG · US

Inventors

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

Key dates

Filing date	Mar 2, 2006
Grant date	Nov 10, 2009
Priority date	—
Expiry date	Mar 2, 2026

Classification

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

Abstract

The present invention relates to the use of a catalyst comprising at least one first catalyst zone located towards the gas inlet, a second catalyst zone located closer to the gas outlet and a third catalyst zone located even closer to or at the gas outlet for the preparation of phthalic anhydride by gas-phase oxidation of o-xylene and/or naphthalene, with the catalyst zones preferably each having an active composition comprising TiO2, characterized in that the catalyst activity of the first catalyst zone is higher than the catalyst activity of the second catalyst zone. Furthermore, a preferred process for the preparation of phthalic anhydride is described.

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