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:
Sep. 02, 1980
Filed:
Jan. 25, 1979
Kurt Halcourt, Leverkusen, DE;
Paul Losacker, Leichlingen, DE;
Manfred Martin, Cologne, DE;
Norbert Schenk, Leverkusen, DE;
Wulf Schwerdtel, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process has been found for the preparation of anthraquinone by catalytic oxidation of naphthalene in the gas phase to provide a reaction product, obtained by quenching, cooling or quenching and cooling, containing naphthaquinone and phthalic anhydride, treating said reaction product directly with butadiene to provide tetrahydroanthraquinone, oxidation by means of molecular oxygen to the tetrahydroanthraquinone contained in this reaction product, to give anthraquinone, and separation of naphthalene, phthalic anhydride, anthraquinone and by-products by distillation, the gases produced in the quenching and/or cooling of the gases from the naphthalene oxidation and the gases from the oxidation of the tetrahydroanthraquinone to give anthraquinone being completely or partially recycled to the oxidation of naphthalene, in which a compound with an alkaline reaction is introduced between the reactor in which naphthalene is oxidized and the reactor in which the reaction with butadiene takes place, and/or into the gas streams which are recycled to the oxidation of naphthalene. The process of the invention reduces considerably the formation of higher-boiling products formed in the continuous preparation of anthraquinone from naphthalene and increases the selectivity of the conversion of naphthalene to anthraquinone. In addition, the process of the invention provides greater freedom in separation of the reaction products since the production of troublesome high-boilers is minimized; and the process results in a reduced formation of carbon dioxide in the oxidation of naphthalene.