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:
Jun. 18, 2002
Filed:
Mar. 07, 2001
Yukihiro Matsumoto, Kobe, JP;
Takeshi Nishimura, Himeji, JP;
Kazuhiko Sakamoto, Himeji, JP;
Hidefumi Haramaki, Himeji, JP;
Nippon Shokubai Co., Ltd., , JP;
Abstract
In a method for producing acrylic acid by the steps of a reaction of catalytic gas phase oxidation, absorbing the acrylic acid with an absorbent, and dehydrating the acrylic acid-containing aqueous solution, the method is characterized that the step of dehydration comprises adding and an azeotropic solvent, distilling the resultant mixture, and adjusting the acrylic acid concentration at the top of the column in the range of 0.06-0.80 wt. %, thereby preventing the bottoms of the azeotropic dehydration column from substantially containing the azeotropic solvent and water. As results, the acrylic acid is kept from forming a polymer in any of the distillation columns involved in the production, and effective utilization of acrylic acid.