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. 09, 2002
Filed:
Apr. 23, 1999
Tadanori Hara, Kitakyushu, JP;
Nobuyoshi Nakamura, Kitakyushu, JP;
Nippon Steel Chemical Co., Ltd., Tokyo, JP;
Abstract
This invention relates to the vapor-phase oxidation of hydrocarbons by passing a gaseous mixture comprising of a molecular oxygen-containing gas and hydrocarbons which may contain substituents to a fixed bed of catalyst and provides a process for vapor-phase oxidation to be effected by passing a gaseous mixture of raw materials to a fixed bed of catalyst in which the void ratio of the catalyst layers increases by stages in one step or more from upstream downward in the flow of the gaseous mixture of raw materials. For example, the process can oxidize in vapor phase such hydrocarbons as naphthalene, xylene, benzene, toluene, durene, butene, acenaphthene, anthracene, indene and their derivatives in high yields with high productivity. Moreover, the process can prepare phthalic anhydride in high yields with high productivity by the vapor-phase oxidation of naphthalene or ortho-xylene.