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. 22, 1976
Filed:
Oct. 25, 1974
Applicant:
Inventors:
Friedrich Wirth, Ludwigshafen, DT;
Erich Renauer, Ludwigshafen, DT;
Hans Von Ammon, Gruenstadt, DT;
Curt Schneider, Kirchheim, DT;
Hubert Suter, Ludwigshafen, DT;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen (Rhine), DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D / ; B01D / ; C07C / ;
U.S. Cl.
CPC ...
2603 / ; 159 49 ;
Abstract
Maleic anhydride is recovered by evaporating the effluent from the production of phthalic anhydride at from 40.degree. to 150.degree.C and from 50 to 760 mm to a water content of less than 10% by weight, heating the concentrate in a thin-film or falling-film evaporator at from 100 to 600 mm at from 120.degree. to 180.degree.C and distilling it in a column. The pure maleic anhydride is withdrawn laterally and the aqueous condensate is recycled to the offgas scrubber.