公开(公告)号：EP2294060A1

公开(公告)日：2011-03-16

申请号：EP09728771.8

申请日：2009-03-23

Applicant: BASF SE

Inventor： WINDECKER, Gunther ,  WEIGUNY, Jens ,  WECK, Alexander ,  DAHLHOFF, Ellen ,  WEIßKER, Wolf-Steffen ,  HEILEK, Jörg ,  KRUG, Thomas ,  FREYBERGER, Ralf

IPC: C07D307/60

CPC classification number: C07C51/573 ,  C07C57/145

Abstract: Process for decreasing fumaric acid deposits during the production of maleic anhydride by heterogeneous catalytic oxidation of a hydrocarbon with molecular oxygen in which the maleic anhydride is absorbed from the crude product mixture in an absorbent in an absorption column and desorbed again in a desorption column, wherein the total amount or a subquantity of the maleic anhydride-depleted absorbent, for targeted precipitation of the fumaric acid, is cooled and/or concentrated by vaporizing a part of the absorbent until the difference between the concentration of fumaric acid in the recycle stream at the outlet of the desorption column, under the conditions prevailing there and the equilibrium concentration of fumaric acid according to the solubility curve after the cooling and/or evaporation of a part of the absorbent is greater than or equal to 250 ppm by weight and the fumaric acid which is precipitated out as solid is removed in whole or in part from the absorbent recycle and the fumaric acid-depleted absorbent is recycled in whole or in part to the absorption column.