公开(公告)号：DE10344264A1

公开(公告)日：2005-04-21

申请号：DE10344264

申请日：2003-09-23

Applicant: BASF AG

Inventor： BORGMEIER FRIEDER ,  ROSOWSKI FRANK ,  LINTZ HANS-GUENTHER ,  GRISSTEDE INA

IPC: C07C51/215 ,  C07C57/05 ,  B01J23/31

Abstract: Preparation of (meth)acrylic acid involves heterogeneously catalyzed gas phase partial oxidation of at least one saturated hydrocarbon precursor compound (C1) at elevated temperature by conducting a starting reaction gas mixture comprising (C1), molecular oxygen, and at least one inert gas through at least one catalyst bed (I). The oxidation reaction in catalyst bed (I) is interrupted at least once by continuing in a catalyst bed (II). Preparation of (meth)acrylic acid involves heterogeneously catalyzed gas phase partial oxidation of at least one saturated hydrocarbon precursor compound (C1) at elevated temperature by conducting a starting reaction gas mixture comprising (C1), molecular oxygen, and at least one inert gas through at least one catalyst bed (I), whose catalysts (I) have active composition containing at least one multimetal oxide (I) which contains the elements Mo and V, at least one element from Te and Sb, and at least one element selected from Nb, Ta, W, Ce or Ti; and whose X-ray diffractogram (I) is as given in the specification. The gas phase partial oxidation of the reaction gas mixture over the catalysts (I) in at least one catalyst bed (I) is interrupted at least once by continuing the gas phase partial oxidation in at least one catalyst bed (II), whose catalysts (II) have their active composition containing at least one multimetal oxide (II), and whose X-ray diffractogram (II) is different from the X-ray diffractogram (I) and has a stoichiometry of general formula: Mo12BiaFeb(X1>)c(X2>)d(X3>)e(X4>)fOn, (A); or a general formula: [(Y1>)a'(Y2>)b'Ox]p[(Y3>)c'(Y4>)d'(Y5>)e'(Y6>)f'(Y7>)g'(Y2>)h'Oy]q, (B). X1>nickel and/or cobalt; X2>thallium, alkali metal and/or alkaline earth metal; X3>zinc, phosphorus, arsenic, boron, antimony, tin, cerium, lead and/or tungsten; X4>silicon, aluminum, titanium and/or zirconium; a : 0.2 - 5; b : 0.01 - 5; c and f : 0 - 10; d : 0 - 2; e : 0 - 8; n : number determined by the valency and frequency of the elements in formula (A) other than oxygen; Y1>only bismuth or bismuth and at least one of tellurium, antimony, tin or copper; Y2>molybdenum and/or tungsten; Y3>alkali metal, thallium and/or samarium; Y4>alkaline earth metal, nickel, cobalt, copper, manganese, zinc, tin, cadmium and/or mercury; Y5>iron, or iron and at least one element from vanadium, chromium, and cerium; Y6>phosphorus, arsenic, boron and/or antimony; Y7>a rare earth metal, titanium, zirconium, niobium, tantalum, rhenium, ruthenium, rhodium, silver, gold, aluminum, gallium, indium, silicon, germanium, lead, thorium and/or uranium; a' : 0.01 - 8; b' : 0.1 - 30; c' : 0 - 4; d' : 0 - 20; e' : greater than 0 - 20; f' : 0 - 6; g' : 0 - 15; h' : 8 - 16; x and y : numbers determined by the valency and frequency of the elements other than oxygen in formula (B); and p and q : numbers whose p/q ratio is 0.1 - 10.