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. 07, 1985
Filed:
Dec. 28, 1983
James T Wrobleski, St. Louis, MO (US);
Monsanto Company, St. Louis, MO (US);
Abstract
Maleic anhydride is produced by the oxidation of a nonaromatic hydrocarbon having at least four carbon atoms in a straight chain with molecular oxygen or a molecular oxygen-containing gas in the vapor phase in the presence of a phosphorus-vanadium mixed oxide catalyst. Such catalysts are prepared by contacting a tetravalent vanadium compound, dissolved in an aqueous, non-oxidizing acid medium, with crystalline diphosphoric acid to form a phosphorus-vanadium mixed oxide catalyst precursor. The resulting catalyst precursor-containing solution is subjected to a series of concentration/dilution cycles to induce crystallization of the catalyst precursor. The crystals are collected, dried, formed into desired structures, and calcined at temperatures from about 300.degree. C. to about 600.degree. C.