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:
Jul. 02, 2013
Filed:
Mar. 23, 2009
Gunther Windecker, Ludwigshafen, DE;
Jens Weiguny, Freinsheim, DE;
Alexander Weck, Freinsheim, DE;
Ellen Dahlhoff, Limburgerhof, DE;
Wolf-steffen Weiβker, Lambsheim, DE;
Jörg Heilek, Bammental, DE;
Thomas Krug, Worms, DE;
Ralf Freyberger, Shanghai, CN;
Gunther Windecker, Ludwigshafen, DE;
Jens Weiguny, Freinsheim, DE;
Alexander Weck, Freinsheim, DE;
Ellen Dahlhoff, Limburgerhof, DE;
Wolf-Steffen Weiβker, Lambsheim, DE;
Jörg Heilek, Bammental, DE;
Thomas Krug, Worms, DE;
Ralf Freyberger, Shanghai, CN;
BASF SE, , DE;
Abstract
Processes for decreasing fumaric acid deposits in preparing maleic anhydride by heterogeneously catalyzed oxidation of a hydrocarbon with molecular oxygen. Maleic anhydride is absorbed from the crude mixture in an absorbent in an absorption column and desorbed in a desorption column, the entirety or portion of absorbent depleted in maleic anhydride, for controlled precipitation of fumaric acid, being cooled and/or concentrated by evaporating a portion of absorbent such that the difference between the concentration of fumaric acid in the recycle stream at the outlet of the desorption column under existing conditions and the equilibrium concentration of fumaric acid according to the solubility curve after cooling and/or evaporation of a portion of absorbent is ≧250 ppm by weight, and the fumaric acid precipitated as a solid is removed completely or partly from the absorbent recycling system and the fumaric acid-depleted absorbent is recycled completely or partly to the absorption column.