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. 03, 1986
Filed:
Jul. 27, 1984
Hiroshi Hashizume, Kurashiki, JP;
Yoshiaki Izumisawa, Kitakyushu, JP;
Mitsubishi Chemical Industries Limited, Tokyo, JP;
Abstract
A process for producing terephthalic acid from p-xylene continuously, wherein p-xylene is oxidized to terephthalic acid by air in the presence of a catalyst containing cobalt, manganese and bromine at a temperature of 180.degree. to 230.degree. C. in a water containing acetic acid solvent in which the concentration of oxygen gas contained in an exhaust gas obtained from the reaction vessel used for oxidizing p-xylene is 2 to 8% by volume, said process comprising, (a) preparing an oxidation exhaust gas by condensing a gas withdrawn from said reaction vessel for removing condensates from said gas, (b) dividing the prepared oxidation exhaust gas into a discharged gas and a recycled gas, in which the volume ratio of said recycled gas to said discharged gas is 0.3 to 5, said discharged gas being exhausted to the outside of the reaction system, (c) supplying continuously said recycled gas to the liquid phase of said reaction vessel, and (d) carrying out the oxidation reaction of p-xylene under reaction pressure higher than the pressure of the reaction system when gas is not recycled to the system.