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. 08, 1982
Filed:
Mar. 16, 1981
Jacques D Hanotier, Lasne Chapelle St. Lambert, BE;
Monique J Hanotier-Bridoux, Lasne Chapelle St. Lambert, BE;
Labofina S.A., Brussels, BE;
Abstract
Disclosed is a process for the continuous production of terephthalic acid from p-xylene, comprising the steps of oxidizing p-xylene in a first oxidation zone in the presence of not more than about 10 weight % of water and a cobalt/manganese catalyst up to a conversion of about 15% terephthalic acid; oxidizing the partially-oxidized compounds in a second oxidation zone in the presence of an additional amount of water up to about 20 to 70% by weight and in the presence of an additional amount of the catalyst up to a conversion of about 50% by weight terephthalic acid; stripping p-xylene vapors from the second oxidation zone; separating crystals of crude terephthalic acid from the effluent from the second oxidation zone from the soluble components of the effluent; countercurrently washing the separated crystals with fresh water to produce a slurry; recycling a part of soluble components to the second oxidation zone, and another part of the first oxidation zone to provide the latter with heavy metal catalyst; and recovering purified terephthalic acid by recyrstallizing the crystals contained in the slurry.