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:
May. 25, 1993
Filed:
May. 07, 1991
Francis J Healy, Florham Park, NJ (US);
Herbert P Dengler, Baton Rouge, LA (US);
Exxon Chemical Patents Inc., Linden, NJ (US);
Abstract
A system for producing phthalic anhydride by vapor phase oxidation of orthoxylene, naphthalene or the like which comprises an oxidation section, and a finishing section comprising: a means for decomposing crude phthalic anhydride liquid such that water, various other by-products and small amounts of phthalic anhydride are removed from the crude phthalic anhydride liquid as decomposer vapor; a means for venting decomposer vapor directly to a top portion of a first fractionation column; the first fractionation column being capable of distilling crude phthalic anhydride liquid received from the decomposer means for the purpose of removing light ends therefrom and which is also capable of recovering phthalic anhydride contained within vapors being vented therefrom; and a second fractionation column capable of distilling the crude phthalic anhydride liquid from the first fractionation column and removing tailings therefrom to produce substantially pure phthalic anhydride; whereby phthalic anhydride is recovered from the decomposer vapor and whereby use of a decomposer condenser and associated jet ejectors or vacuum pumps are avoided.