Patent · US Expired

Generation of reduced pressure in apparatuses in the preparation of phthalic anhydride and maleic anhydride

US4675420A · kind A · utility

8Cited by

1References

4Claims

0Family size

Assignee

BASF SE

Inventors

Ulrich Block · Ludwigshafen, DE
Wolf Muff · Laumersheim, DE
Klaus Nixdorf · Frankenthal (Pfalz), DE
Joachim Wagner · Ludwigshafen, DE

Key dates

Filing date	Sep 11, 1985
Grant date	Jun 23, 1987
Priority date	—
Expiry date	Sep 11, 2005

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C51/31
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

In apparatuses for the preparation of phthalic anhydride and/or maleic anhydride by catalytic oxidation of naphthalene or o-xylene with air, reduced pressure is generated using liquid-jet pumps, and wash liquid is removed from the exit gas washer as a pump fluid for the liquid-jet pumps and is subsequently recycled to the exit gas washer.

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