Shaped catalyst body for partial oxidation reactions
View Patent ↗The invention relates to a shaped catalyst body for preparing maleic anhydride, which comprises mixed oxides of vanadium and of phosphorus as catalyst components. To develop a generic shaped catalyst body further so that it has improved properties, it is proposed that the basic geometric body enveloping the shaped catalyst body ( 100; 200 ) be a prism ( 180 ) having a first triangular face and a second triangular face and the shaped catalyst body ( 100; 200 ) be provided with three through openings ( 111, 121, 131; 211, 221, 231 ) which extend from a first face of the shaped body ( 100; 200 ) which contacts the first triangular face of the prism ( 180 ) to a second face of the shaped body ( 100; 200 ) which contacts the second triangular face of the prism ( 180 ).
1. A shaped catalyst body for preparing maleic anhydride, comprising mixed oxides of vanadium and of phosphorus as catalyst component, having a fundamental geometric shape of the envelope of the shaped catalyst body ( 100 ; 200 ) of a prism ( 180 ) having a first and a second triangular face, the shaped catalyst body ( 100 ; 200 ) being provided with continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) which extend from a first face of the shaped body ( 100 ; 200 ) forming the first triangular face of the prism ( 180 ) to a second face of the shaped body ( 100 ; 200 ) which forms the second triangular face of the prism ( 180 ).
2. The shaped catalyst body as claimed in claim 1 , wherein the shaped body ( 100 ; 200 ) has an essentially triangular cross section with rounded vertices.
3. The shaped catalyst body as claimed in claim 1 , wherein the shaped body ( 100 ; 200 ) has an essentially trilobal cross section and each lobe ( 110 , 120 , 130 ) is provided with a continuous orifice ( 111 , 121 , 131 ; 211 , 221 , 231 ).
4. The shaped catalyst body as claimed in claim 3 , wherein two of the three lobes ( 110 , 120 , 130 ) have the same external diameter ( 150 ).
5. The shaped catalyst body as claimed in claim 3 , wherein all of the lobes ( 110 , 120 , 130 ) have a different external diameter ( 150 ).
6. The shaped catalyst body as claimed in claim 3 , having a ratio of the length ( 160 ) of the shaped body ( 100 ; 200 ) to the minimum width of the end face ( 170 ) of the trilobal shaped body ( 100 ) of from 0.5 to 2.
7. The shaped catalyst body as claimed in claim 1 , wherein the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) have a circular or oval cross section.
8. The shaped catalyst body as claimed in claim 1 , wherein the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) have a diameter ( 140 ; 240 ) of from 0.5 mm to 3 mm.
9. The shaped catalyst body as claimed in claim 1 , wherein the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) have the same diameter ( 140 ; 240 ).
10. The shaped catalyst body as claimed in claim 1 , wherein each of the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) has a different diameter ( 140 ; 240 ).
11. The shaped catalyst body as claimed in claim 1 , wherein the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) run essentially parallel to one another.
12. The shaped catalyst body as claimed in claim 1 , wherein the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) are essentially equally spaced apart from one another.
13. The shaped catalyst body as claimed in claim 1 , having a the ratio of the intermediate spacing between the continuous orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) to the diameter ( 140 ; 240 ) of the orifices ( 111 , 121 , 131 ; 211 , 221 , 231 ) of from 1.15 to 1.5.
14. The shaped catalyst body as claimed in claim 1 , wherein the shaped body ( 100 ; 200 ) has a length ( 160 ) of from 2 to 20 mm.
15. The shaped catalyst body as claimed in claim 1 , having a ratio of the volume of the shaped body ( 100 ; 200 ) V shaped body to the volume of the envelope prism ( 180 ) V prism of from 0.71 to 0.9.
16. The shaped catalyst body as claimed in claim 1 , wherein the geometric surface area of the shaped body ( 100 ; 200 ) is from 0.15 cm 2 to 5 cm 2 .
17. The shaped catalyst body as claimed in claim 1 , having a ratio of geometric surface areas of the shaped body ( 100 ; 200 ) to the volume of the shaped body ( 100 ; 200 ) is from 0.5 to 20 mm −1 .
18. The shaped catalyst body as claimed in claim 1 , having a bulk density of the shaped body of from 0.4 g/cm 3 to 1.4 g/cm 3 .
19. The shaped catalyst body as claimed in claim 1 , having a mechanical strength of the shaped body ( 100 ; 200 ) of from 4.0 N to 300 N.
20. The shaped catalyst body as claimed in claim 1 , having a BET surface area of the shaped body of from 5 to 300 m 2 /g.
21. The shaped catalyst body as claimed in claim 1 , having an integral pore volume>100 mm 3 /g.
22. The shaped catalyst body as claimed in claim 1 , having a content of the catalyst component of from 3% by weight to 50% by weight, based on the total weight of the shaped catalyst body.
23. The shaped catalyst body as claimed in claim 1 , wherein the catalyst component has the formula
VP x O y M z
in which M is at least one promoter, x is from 0.1 to 3, y is a number according to the valences of V, P and M, and z is from 0 to 1.5.
24. The shaped catalyst body as claimed in claim 23 , wherein the promoter is present and is chromium, nickel, magnesium, aluminum, silicon, tungsten, niobium, antimony, lithium, zinc, tellurium, silver, iron, bismuth, molybdenum and/or cesium or mixtures thereof.
25. The shaped catalyst body as claimed in claim 23 , having a proportion of the promoter in the form of an oxide or in the form of a compound convertible to an oxide of from 0.005% to 5% by weight based on the total weight of the shaped body.
26. A method for preparing maleic anhydride from hydrocarbons, comprising subjecting said hydrocarbons to partial oxidation in the presence of a catalyst according to claim 1 .
27. A method as claimed in claim 26 , where n-butane is used as the hydrocarbon.