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:
Apr. 14, 1981
Filed:
Apr. 28, 1980
Abraham P Gelbein, Morristown, NJ (US);
Chem Systems Inc., New York, NY (US);
Abstract
In a process for preparing phthalic anhydride, o-xylene is oxidized with air in a dilute phase transported bed reactor. The reaction is initiated with an o-xylene concentration above the upper flammability limit. Air is injected to a plurality of points along the reactor so as to prevent the oxygen concentration in the reactor from falling too low to maintain catalyst activity, while, at the same time, staying outside of the flammability envelope of the organic-oxygen mixtures. The process permits use of overall o-xylene/oxygen ratios which are substantially higher than were heretofore possible because of safety considerations, thereby minimizing the quantity of inert gases in the system, which reduces the size the complexity of the product recovery system.