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:
Jan. 22, 1991
Filed:
Jun. 27, 1988
Morimasa Kuragano, Sakai, JP;
Kozo Iwasaki, Yokohama, JP;
Takeshi Isobe, Takaishi, JP;
Isao Fukada, Takaishi, JP;
Minoru Koshibe, Sakai, JP;
Yoshihiro Sezaki, Izumi, JP;
Hirozo Segawa, Kitakanbara, JP;
Katsuji Yoguchi, Kitakanbara, JP;
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Kyowa Gas Chemical Industry Co., Ltd., Tokyo, JP;
Abstract
In order to recover methacrolein and/or methacrylic acid by quenching a reaction product gas obtained by catalytic oxidation of isobutylene or the like, the reaction product gas is charged into a quench column through a double-wall pipe and is then brought into contact with a condensate as a cooling medium. Deposition of terephthalic acid and the like inside the column is prevented by controlling the temperature of a bottom in the quench column and that of an overhead gas of a quench column unit. An aromatic carboxylic acid, aromatic aldehyde, metal powder is added to an aqueous solution of methacrylic acid, which contains terephthalic acid and the like, so that the terephthalic acid and the like are caused to precipitate for their removal.