Composite material containing a bismuth-molybdenum-nickel mixed oxide or a bismuth-molybdenum-cobalt mixed oxide and SiO.SUB.2

Abstract

The present invention relates to a process for producing a composite material and also the composite material itself. The composite material contains a bismuth-molybdenum-nickel mixed oxide or a bismuth-molybdenum-cobalt mixed oxide and a specific SiO2 as pore former. The present invention also relates to the use of the composite material according to the invention for producing a washcoat suspension and also a process for producing a coated catalyst using the composite material according to the invention. Furthermore, the present invention also relates to a coated catalyst which has a catalytically active shell comprising the composite material according to the invention on a support body. The coated catalyst according to the invention is used for preparing [alpha],[beta]-unsaturated aldehydes from olefins.

Claims

1. A composite material containing bismuth-molybdenum-nickel mixed oxide or bismuth-molybdenum-cobalt mixed oxide and SiO.sub.2, the SiO.sub.2 having a pore volume in the range from 0.1 to 10 ml/g and an average particle size in the range from 3 to 20 m.

2. The composite material according to claim 1, wherein the composite material is a spray-calcined product of a spray composition comprising particulate porous SiO.sub.2 having a pore volume in the range from 0.1 to 10 mL/g and an average particle size in the range from 3 to 20 m; and salts of nickel, bismuth and molybdenum.

3. The composite material according to claim 2, wherein the spray-calcined product is made by spray-calcining the spray composition at a temperature in the range of 200600 C.

4. The composite material according to claim 1, wherein the composite material is a spray-calcined product of a spray composition comprising particulate porous SiO.sub.2 having a pore volume in the range from 0.1 to 10 mL/g and an average particle size in the range from 3 to 20 m; and precipitated salts of nickel, bismuth and molybdenum.

5. The composite material according to claim 4, wherein the spray-calcined product is made by spray-calcining the spray composition at a temperature in the range of 200600 C.

6. The composite material according to claim 1, wherein the composite material is made by a method comprising: (a) preparing a first aqueous solution containing salts of bismuth and of nickel; (b) preparing a second aqueous solution containing a molybdenum compound; (c) adding the first aqueous solution to the second aqueous solution, forming a first suspension; (d) adding a second suspension to the first suspension to form a third suspension, the second suspension containing SiO.sub.2 which has a pore volume in the range from 0.1 to 10 ml/g and an average particle size in the range from 3 to 20 m; and (e) spray-calcining the third suspension at a temperature in the range from 200 to 600 C., to give the composite material containing a bismuth-molybdenum-nickel mixed oxide or bismuth-molybdenum-cobalt mixed oxide.

7. The composite material according to claim 1, wherein the particulate porous SiO.sub.2 has a pore volume in the range of 0.5 to 5 mL/g.

8. The composite material according to claim 1, wherein the particulate porous SiO.sub.2 has a pore volume in the range of 1 to 2 mL/g.

9. The composite material according to claim 1, wherein the particulate porous SiO.sub.2 has an average particle size in the range of 5 to 15 m.

10. The composite material according to claim 1, wherein the particulate porous SiO.sub.2 has an average particle size in the range of 8 to 11 m.

11. The composite material according to claim 1, wherein the particulate porous SiO.sub.2 an oil absorption value in the range of from 250 g/100 g to 400 g/100 g.

12. The composite material according to claim 1, having a BET surface area in the range of 20 to 60 m.sup.2/g.

13. The composite material according to claim 1, having a pore volume in the range of 0.08 to 0.24 cm.sup.3/g.

14. The composite material according to claim 1, having a pore volume in the range of 0.12 to 0.20 cm.sup.3/g.

15. The composite material according to claim 1, wherein particles of the composite material have a d.sub.90 particle size of less than 125 m, a d.sub.50 particle size less than 50 m, and a d.sub.10 particle size less than 7 m.

Description

FIGURES

(1) FIG. 1: FIG. 1 shows, in a diagram, the conversion of propene as a function of the reactor temperature, using an inventive coated catalyst as per example 3 and using a solid extrudate catalyst as per comparative example 1.

(2) FIG. 2: FIG. 2 shows the sum of selectivity to acrolein and acrylic acid as a function of the amount of converted propene for an inventive coated catalyst as per example 3 and a solid extrudate catalyst as per comparative example 1.

(3) FIG. 3: FIG. 3 shows the sum of yield of acrolein and acrylic acid as a function of the amount of consumed propene for an inventive coated catalyst as per example 3 and a solid extrudate catalyst as per comparative example 1.

(4) FIG. 4: FIG. 4 shows, in a diagram, the conversion of propene as a function of the reactor residence time, using an inventive coated catalyst as per example 3 and using a coated catalyst as per comparative example 2.

(5) FIG. 5: FIG. 5 shows the sum of yield of acrolein and acrylic acid as a function of the amount of consumed propene for an inventive coated catalyst as per example 3 and a coated catalyst as per comparative example 2.

(6) FIG. 6: FIG. 6 shows the sum of selectivity to acrolein and acrylic acid as a function of the amount of converted propene for an inventive coated catalyst as per example 3 and a coated catalyst as per comparative example 2.

(7) FIG. 7: FIG. 7 shows, in a diagram, the conversion of propene as a function of the reactor residence time, using an inventive coated catalyst as per example 3 and using a coated catalyst as per comparative example 3.

(8) FIG. 8: FIG. 8 shows the sum of selectivity to acrolein and acrylic acid as a function of the amount of converted propene for an inventive coated catalyst as per example 3 and a catalyst as per comparative example 3.

(9) FIG. 9: FIG. 9 shows the sum of yield of acrolein and acrylic acid as a function of the amount of consumed propene for an inventive coated catalyst as per example 3 and a catalyst as per comparative example 3.

EXAMPLES

Example 1

Production of an Inventive Composite Material

(10) A 5 liter glass beaker is charged with 0.727 kg of distilled water, which is heated to 60 C. Then 1.02 kg of iron nitrate nonahydrate (Honeywell; batch: B1960) are added. Without further heating, 2.37 kg of nickel nitrate hexahydrate (ALFA Aesar; batch: 61101000) and 0.62 kg of magnesium nitrate hexahydrate (Honeywell; batch: 90140) are then added, and the mixture is stirred until this has likewise dissolved. Following renewed heating to 50 C., 0.039 kg of 1M KOH (Merck; batch: HC111978) is added. Following the addition of the potassium hydroxide, a brown precipitate can be seen, but quickly dissolves again. Then 0.3 kg of bismuth nitrate pentahydrate (ALFA Aesar; batch: 42060004) is added. The solution is stirred at 35 C. for about 12 hours.

(11) In a further batch, 8.3 kg of distilled water are initially introduced. Then 2.62 kg of ammonium heptamolybdate tetrahydrate (HC Starck; batch: 1163/048) are added to the solution and dissolved with stirring at 35 C. 1.1 kg of Bindzil 2034Di (Akzo Nobel; batch: N00210) are added thereto. Measurement of the pH at a temperature of 33 C. gave a pH of 5.33.

(12) The solution prepared first, and stirred overnight, was pumped using a peristaltic pump (WATSON MARLOW 323E/D), into the freshly prepared solution with the ammonium heptamolybdate. The pumping procedure took about 26 minutes. Then the resulting suspension was admixed with 1.88 kg of a 0.1% solution of Praestol 611BC (Ashland 004041281623233) and 0.19 kg of Syloid C809 (Grace Davison; batch: 1000214955). The pH of the resulting suspension was 1.26. The resulting solution was stirred for 3 hours, before being sprayed into a pulsation reactor from IBU-tec (model: PR-4). The temperature in the pulsation reactor was 500 C. and the residence time was in the range from 200 ms to 2 s.

(13) The yield of the resulting inventive composite material following discharge from the pulsation reactor was 2.20 kg. The BET surface area of the composite material was 40 m.sup.2/g. The pore volume of the composite material was 0.16 cm.sup.3/g. The particle size distribution was as follows:

(14) d.sub.10=122 m

(15) d.sub.50=47 m

(16) d.sub.90=4.2 m

Example 2

Production of an Inventive Washcoat Suspension

(17) In the first production step, 2. 20 g of Geniosil GF95 (Wacker GD18168) and 1.69 g of 1M potassium hydroxide solution are introduced into 200 ml of distilled H.sub.2O. Then first 128.21 g of the composite material produced in example 1, 9.62 g of Coconit 300 (Mahlwerk Neubauer-Friedrich Geffers) and 3.21 g of Syloid C809 (Grace Davison; batch: 1000214955) are suspended in the distilled water/Geniosil/KOH mixture produced in the 1.sup.st step.

(18) This is followed by an Ultra-Turrax treatment at 8000 rpm for about 2.5 minutes (T50 from IKA).). After the Turrax treatment, the suspension is transferred, with a further 300 ml of distilled H.sub.2O, into a glass beaker, and 28.28 g of Bindzil 2034 Di (N00210) are added. This is followed by brief stirring and then by addition of 25.64 g of the organic binder EP 16 (from Wacker).

Example 3

Production of an Inventive Coated Catalyst

(19) 200 g of steatite spheres measuring 4.5 mm (EXACER # N.27/11) are swirled with air in an Innojet Aircoater 025 to form a fluidized bed, the temperature of the process air being 90 C. Subsequently, at a nozzle pressure of 1.0 bar and at a spraying rate of 4 g/min per 200 g of support body for coating, the washcoat suspension produced according to example 2 was introduced by spraying.

(20) After the end of the spraying operation, the fluidization by the process air is halted, and the coated support bodies are discharged from the coating apparatus and then calcined in a calcining oven first at 400 C. for 2 hours and then, subsequently, at 610 C. for 3 hours.

(21) The shell thickness of the catalytically active coating was 761 m and the weight fraction of the applied coating was 27.4%.

(22) In the present specification, the shell thickness is determined using the so-called slide caliper. In this case, an electronic slide caliper is used to measure the diameter of 40 catalyst beads, the average is formed, and then the diameter of the pure support beads is subtracted.

Comparative Example 1

Production of a Solid Extrudate Catalyst

(23) First of all a bismuth-molybdenum mixed oxide powder was produced as per example 2 of DE 10 2008 017 308.

(24) 400 g of bismuth-molybdenum mixed oxide powder are introduced together with 23-53 g. of Syloid C809 (Grace Davison 1000214955), 35.29 g of Zusoplast C 92 (ZSCHWIMMER & SCHWARZ Ch. 143048 001) and 11.76 g of corn starch (batch QF05012412) into an extruder (Herrman Linde extruder model: LKII2) and mixed dry for 5 minutes. Then 117.65 g of Ludox AS 40 (Grace Davison batch: 510311) are added. Water is then added until an extrudable mass is produced (250 ml, approximately 50 ml every 3 minutes). Following the addition of 200 ml of water, compounding takes place for 15 minutes, and a further 50 ml are added in portions. Then 14.12 g g of steatite oil (Freidling from PA 10.12.10) are added, and compounding continues for 5 minutes more. (total compounding time: 40 min).

(25) The compounded material thus obtained is introduced gradually into an ECT extruder. Die: 6 mm extrudates, 3 hole die; settings: drive screw: 30 rpm; pressure 7 to 8 bar.

(26) The extrudates obtained are then dried in a VENTI-Line drying cabinet at 120 C. for one day. The dried extrudates are then calcined in a Nabertherm forced air oven at 590 C. for 8 hours. Calcining produces a weight loss of approximately 11% in the extrudates.

Comparative Example 2

Production of a Noninventive Coated Catalyst

(27) First of all a composite material was produced as per example 1, with the difference that no pore formers were used for this purpose and the calcination was carried out in a calcining oven rather than in an IBU-tec pulsation reactor.

(28) In accordance with example 2, a washcoat suspension was produced from the composite material produced accordingly, with the difference that, here again, no pore formers were added.

(29) The resulting washcoat suspension was used to produce a coated catalyst in the same way as for example 3.

Comparative Example 3

(30) First of all, a composite material was produced as per example 1, with the difference that no pore formers were used for this purpose. In accordance with example 2, a washcoat suspension was produced from the composite material produced accordingly, with the difference that, here again, no pore formers were added.

(31) The resulting washcoat suspension was used to produce a coated catalyst in the same way as for example 3.

Catalytic Tests

(32) The inventive coated catalyst of example 3 and the solid extrudate catalyst of comparative examples 1 to 3 were investigated for their catalytic performance in the conversion of propene to acrolein and acrylic acid. The feed composition here was 8.0 vol % water, 9.0% propene and 14.4% oxygen, the remainder being inert gas. The total flow rate in this case was 78 ml/min for each tube of the catalyst apparatus.

(33) The catalytic performances of the inventive coated catalyst and of the solid extrudate catalyst are apparent from FIGS. 1 to 3. The catalytic performances of the inventive coated catalyst and of the catalyst of comparative example 2 are evident from FIGS. 4 to 6. The catalytic performances of the inventive coated catalyst and of the catalyst of comparative example 3 are evident from FIGS. 7 to 9.