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. 24, 1994
Filed:
Jan. 04, 1993
Kazuhiko Sakamoto, Himeji, JP;
Hiroaki Tanaka, Himeji, JP;
Masatoshi Ueoka, Himeji, JP;
Yoji Akazawa, Himeji, JP;
Masao Baba, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
A process for producing acrylic acid is described, which process comprising providing a mixed gas of acrylic acid and by-products produced by catalytic gas phase oxidation of propylene and/or acrolein, contacting the mixed gas with water to obtain an aqueous solution, and adding an azeotrope solvent to the aqueous solution for distillation to obtain a mixture of the by-products, water and the azeotrope solvent from a tower top and acrylic acid from a tower bottom. Highly pure acrylic acid is obtained by using, as the azeotrope solvent, a mixed solvent of solvent A selected from diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl-tert-butyl ketone, n-propyl acetate and mixtures thereof and solvent B selected from toluene, heptane, methyl cyclohexane and mixtures thereof.