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. 16, 2006
Filed:
Mar. 12, 2003
Hiromi Yunoki, Himeji, JP;
Michio Tanimoto, Himeji, JP;
Hiromi Yunoki, Himeji, JP;
Michio Tanimoto, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
The object of the present invention is to provide a process in which, when the unsaturated carboxylic acid is produced, or when the unsaturated aldehyde and/or the unsaturated carboxylic acid are produced by carrying out the catalytic gas phase oxidation reaction by using the fixed-bed multitubular reactor which is packed with the molybdenum-containing catalyst, the reaction can be continued for a long time while a high yield is maintained, regardless of where the hot spot portion occurs and also even if the concentration of the raw gas is high. To solve this object, the present invention production process for an unsaturated carboxylic acid is characterized in: a particulate catalysts including, as catalytic components, an oxide and/or a complex oxide including Mo and V, or Mo, Fe and Bi as essential components, and having a hole are used; and a catalyst-packed layer of each reaction tube of the fixed-bed multitubular reactor is divided into at least two reaction zones in a tubular axial direction, wherein the packing of the catalysts is such that the diameters of the holes of the catalysts differ between at least two of the reaction zones.