Hydrogenation catalyst and process for production thereof by the use of uncalcined starting material

Abstract

The invention relates to a process for preparing a shaped CuAl catalyst body for the hydrogenation of organic compounds containing a carbonyl function. More particularly, the shaped catalyst body is suitable for the hydrogenation of aldehydes, ketones and of carboxylic acids or esters thereof, specifically of fatty acids or esters thereof, such as fatty acid methyl esters, to the corresponding alcohols such as butanediol. The present invention further relates to CuAl catalysts obtainable by the preparation process.

Claims

1. A tableted shaped catalyst body containing copper, aluminum and optionally a transition metal selected from the group consisting of Zn, Si, Ti, Mn, Ni, Cr, Fe, Co, Mo, Ca, Ba, Ce and Zr and mixtures thereof, wherein the tableted shaped catalyst body has a bimodal pore radius distribution which has a first maximum in the range from 10 to 30 nm and a second maximum in the range from 500 to 2500 nm, and wherein from 5 to 30% of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 500 to 2500 nm and from 40 to 90% of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 5 to 50 nm.

2. The tableted shaped catalyst body according to claim 1 containing copper, aluminum and manganese.

3. The tableted shaped catalyst body according to claim 1, wherein the second maximum is in the range from 700 to 2000 nm.

4. The tableted shaped catalyst body according to claim 1, in a reduced form, having copper in an amount in the range from 20 to 50% by weight.

5. The tableted shaped catalyst body according to claim 1, made by a method comprising: (a) combining of (i) at least one aqueous solution of copper compounds, aluminum compounds and optionally transition metal compounds and (ii) at least one aqueous carbonate-containing solution to form a precipitate, isolation of the precipitate, optionally washing of the isolated precipitate and drying of the isolated precipitate to give a dried precipitate, and (b) tableting of the dried precipitate obtained in step (a), wherein step (b) comprises: (b1) calcination of dried precipitate obtained in step (a) at a temperature in the range from 250 to 900 C., to give a calcined precipitate, (b2) mixing of dried precipitate obtained in step (a) with calcined precipitate obtained in step (b1) in a weight ratio of dried precipitate to calcined precipitate in the range from 2:98 to 98:2, to give a mixture, and (b3) tableting of the mixture obtained in step (b2); (c) after-calcination of the tableted shaped catalyst body at a temperature in the range from 250 to 900 C., to give an after-calcined shaped catalyst body; and (d) reduction of the tableted shaped catalyst body obtained from step (b) and/or the after-calcined shaped catalyst body obtained from step (c) to give a reduced shaped catalyst body.

6. A tableted shaped catalyst body containing copper, aluminum and optionally a transition metal selected from the group consisting of Mn, Zn, Ce, Zr and mixtures thereof, wherein the tableted shaped catalyst body has a bimodal pore radius distribution which has a first maximum in the range from 10 to 30 nm and a second maximum in the range from 500 to 2500 nm, and wherein from 10 to 25% of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 500 to 2500 nm and from 45 to 80% of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 5 to 50 nm.

7. The tableted shaped catalyst body according to claim 6 containing copper, aluminum and manganese.

8. The tableted shaped catalyst body according to claim 6, wherein the second maximum is in the range from 700 to 2000 nm.

9. The tableted shaped catalyst body according to claim 6, having a pore volume in the range from 0.1 to 0.6 cm.sup.3/g, determined by the Hg intrusion method in accordance with DIN 66133.

10. The tableted shaped catalyst body according to claim 6, having a pore volume in the range from 0.13 to 0.40 cm.sup.3/g, determined by the Hg intrusion method in accordance with DIN 66133.

11. The tableted shaped catalyst body according to claim 6, in a reduced and stabilized form, having a pore volume in the range from 0.20 to 0.80 cm.sup.3/g, as determined by the Hg intrusion method in accordance with DIN 66133.

12. The tableted shaped catalyst body according to claim 6, in a reduced form, having copper in an amount in the range from 20 to 50% by weight.

13. The tableted shaped catalyst body according to claim 6, free of zinc.

14. The tableted shaped catalyst body according to claim 6, made by a method comprising: (a) combining of (i) at least one aqueous solution of copper compounds, aluminum compounds and optionally transition metal compounds and (ii) at least one aqueous carbonate-containing solution to form a precipitate, isolation of the precipitate, optionally washing of the isolated precipitate and drying of the isolated precipitate to give a dried precipitate, and (b) tableting of the dried precipitate obtained in step (a), wherein step (b) comprises: (b1) calcination of dried precipitate obtained in step (a) at a temperature in the range from 250 to 900 C., to give a calcined precipitate, (b2) mixing of dried precipitate obtained in step (a) with calcined precipitate obtained in step (b1) in a weight ratio of dried precipitate to calcined precipitate in the range from 2:98 to 98:2, to give a mixture, and (b3) tableting of the mixture obtained in step (b2).

15. The tableted shaped catalyst body according to claim 14, wherein the process further comprises: (c) after-calcination of the tableted shaped catalyst body at a temperature in the range from 250 to 900 C., to give an after-calcined shaped catalyst body; and (d) reduction of the tableted shaped catalyst body obtained from step (b) and/or the after-calcined shaped catalyst body obtained from step (c) to give a reduced shaped catalyst body.

16. The tableted shaped catalyst body according to claim 6, made by a method comprising the precipitation of an aqueous solution of copper compounds, aluminum compounds and optionally transition metal compounds and formation of the tableted shaped catalyst body from a resulting precipitate.

17. The tableted shaped catalyst body according to claim 16, wherein the formation of the tableted shaped catalyst body is performed in the absence of a pore former.

18. The tableted shaped catalyst body according to claim 6, made by a method comprising the precipitation of an aqueous solution of copper compounds, aluminum compounds and optionally transition metal compounds and formation of the tableted shaped catalyst body from a resulting precipitate.

19. The tableted shaped catalyst body according to claim 18, wherein the formation of the tableted shaped catalyst body is performed in the absence of a pore former.

20. A tableted shaped catalyst body containing copper, aluminum and optionally a transition metal selected from the group consisting of Mn, Zn, Ce, Zr and mixtures thereof, wherein the tableted shaped catalyst body has a bimodal pore radius distribution which has a first maximum in the range from 10 to 30 nm and a second maximum in the range from 500 to 2500 nm, and wherein from 15 to 25% of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 500 to 2500 nm and from 50 to 70%, of the pore volume of the tableted shaped catalyst body is formed by pores having a pore radius in the range from 5 to 50 nm.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the pore radius distribution, measured using the Hg intrusion method in accordance with DIN 66133, of catalyst 1A as per example 5 after after-calcination but before reduction.

(2) FIG. 2 shows the pore radius distribution, measured by the Hg intrusion method in accordance with DIN 66133, of catalyst 1A as per example 5 after after-calcination and reduction by means of 5% by volume of hydrogen in nitrogen at 200 C. for 4 hours.

EXAMPLES

(3) The invention is illustrated by the following, nonlimiting examples. Even when these examples describe specific embodiments of the invention, they serve merely to illustrate the invention and should not be interpreted as restricting the invention in any way. As a person skilled in the art will know, numerous modifications can be made to these embodiments without going outside the scope of protection of the invention as defined by the accompanying claims.

(4) Determination of Physical Parameters

(5) The physical parameters described here are, unless indicated otherwise, determined as follows:

(6) Conductivity is determined in accordance with DIN 38404, part 8.

(7) Lateral compressive strength is determined in accordance with DIN EN 1094-5.

(8) Remaining loss on ignition is determined in accordance with DIN EN 196-2.

(9) Pore volume and pore radius distribution are determined by the Hg intrusion method in accordance with DIN 66133.

(10) Carbonate content is determined in accordance with DIN ISO 10693.

Example 1 (Production of the Uncalcined Material)

(11) The production of the uncalcined material is carried out via precipitation of the metal nitrates by means of sodium carbonate to form the carbonates thereof, and the precipitate is subsequently filtered off, washed and spray dried.

(12) Solution 1 is produced from 617 g of Cu(NO.sub.3).sub.2.3 H.sub.2O, 106 g of Mn(NO.sub.3).sub.2.4 H.sub.2O, 875 g of Al(NO.sub.3).sub.3.9 H.sub.2O and 5 l of H.sub.2O. Solution 2 is produced from 850 g of Na.sub.2CO.sub.3 and 3.8 l of H.sub.2O. The two solutions are heated to 80 C. and stirred. They are subsequently metered into a precipitation vessel. The pH in the precipitation vessel is 6.8. The volume flows of solutions 1 and 2 are set so that this pH is established. As soon as the two solutions have been consumed, the precipitate formed is filtered off and washed with water. The filter cake is then resuspended in about 1 l of water and spray dried. The resulting dried but still uncalcined powder is the starting material for the further preparations.

Example 2 (Production of the Calcined Material)

(13) The calcined material is produced by calcining the uncalcined dried powder from example 1 at 750 C. in a convection furnace for 2 hours. The remaining loss on ignition of the calcined material at 1000 C. (LOI) is about 5% by weight.

Example 3 (Production of the Comparative Catalyst)

(14) The comparative catalyst is produced by mixing 100 g of calcined powder produced as per example 2 with 3% by weight of graphite and subsequently tableting the mixture to form shaped bodies having a diameter of about 3 mm and a height of about 3 mm. The lateral compressive strength of the comparative catalyst is 85 N, determined in accordance with DIN EN 1094-5.

Example 4 (Production of Catalyst 1)

(15) To produce catalyst 1, 75 g of calcined powder (from example 2) are mixed with 25 g of uncalcined powder (from example 1) and 3 g of graphite and tableted to form shaped bodies having a diameter of about 3 mm and a height of about 3 mm. The lateral compressive strength is 85 N.

Example 5 (Production of Catalyst 1A)

(16) Catalyst 1A is produced in a manner analogous to catalyst 1, but the pellets are calcined at 750 C. in a convection furnace for 2 hours after tableting.

Example 6 (Production of Catalyst 2)

(17) To produce the catalyst 2, 50 g of calcined powder (from example 2) are mixed with 50 g of uncalcined powder (from example 1) and 3 g of graphite and tableted to form shaped bodies having a diameter of about 3 mm and a height of about 3 mm. The lateral compressive strength is 75 N.

Example 7 (Production of Catalyst 2A)

(18) Catalyst 2A is produced in a manner analogous to catalyst 2, but the pellets are calcined at 750 C. in a convection furnace for 2 hours after tableting.

Example 8 (Production of Catalyst 3)

(19) To produce the catalyst 3, 25 g of calcined powder (from example 2) are mixed with 75 g of uncalcined powder (from example 1) and 3 g of graphite and tableted to form shaped bodies having a diameter of about 3 mm and a height of about 3 mm. The lateral compressive strength is 75 N.

Example 9 (Production of Catalyst 3A)

(20) Catalyst 3A is produced in a manner analogous to catalyst 3, but the pellets are calcined at 750 C. in a convection furnace for 2 hours after tableting.

Example 10 (Production of Catalyst 4)

(21) To produce the catalyst 4, 100 g of uncalcined powder (from example 1) and 3 g of graphite are mixed and tableted to form shaped bodies having a diameter of about 3 mm and a height of about 3 mm. The lateral compressive strength is 70 N.

Example 11 (Production of Catalyst 4A)

(22) Catalyst 4A is produced in a manner analogous to catalyst 4, but the pellets are calcined at 750 C. in a convection furnace for 2 hours after tableting.

Example 12 (Activity Measurements)

(23) The activity of the catalysts in respect of the hydrogenation of methyl esters of fatty acids (FAME) is examined. An electrically heated fixed-bed reactor having a reactor volume of 25 ml is used for this purpose. Methyl laurate (C12-methyl ester) is used for the test. To evaluate the conversion of the ester and the selectivity to the fatty alcohol or the formation of bi-products, the reaction product formed is analyzed by gas chromatography. The conversion is calculated from the molar amount of the ester used and the remaining molar amount of ester in the product.

(24) For the analysis by gas chromatography, 6.0000 g of the product formed are mixed with 0.2000 g of 5-nonanol (internal standard). The sample is subsequently analyzed twice by means of a gas chromatograph.

(25) Equipment Used:

(26) GC: Agilent 7890A with FID

(27) Column: ZB-1, 60 m0.25 mm from Phenomenex

(28) Software: EZ Chrom Elite Version 3.3.2 SP1

(29) Test conditions in the hydrogenation of methyl laurate: Temperature points: 240, 180, 160 C., Pressure: 280 bar GHSV (H.sub.2): 20000 h.sup.1 LHSV (ester): 1.4 h.sup.1

(30) Table 1 shows the values for the conversions of C12-methyl ester obtained by the above-described method at 240 C., 180 C. and 160 C. for the comparative catalyst and the catalysts 1 to 4 and 1A to 4A (examples 4 to 11). The improved activity on the catalysts 1 to 4 and 1A to 4A compared to the comparative catalyst can clearly be seen, in particular at 160 C. As the values for the catalysts 1A, 2A, 3A and 4A show, a renewed improvement in the activity is obtained by means of an after-calcination.

(31) TABLE-US-00001 TABLE 1 Conversions of C12-methyl ester at 240, 180 and 160 C. Ratio of uncalcined Conversion of C12-methyl material to ester [%] Catalysts calcined material 240 C. 180 C. 160 C. Comparative 0/100 97.1 81 62.5 catalyst Catalyst 1 25/75 97.9 83.9 72.4 Catalyst 1A 25/75, after- 99.5 98 81.8 calcined Catalyst 2 50/50 97.9 83 70 Catalyst 2A 50/50, after- 98.8 95.2 77.3 calcined Catalyst 3 75/25 97.8 82 67 Catalyst 3A 75/25, after- 98.3 93.5 75.6 calcined Catalyst 4 100/0 97.6 81 66 Catalyst 4A 100/0, after- 98.1 90.1 73.3 calcined

(32) Table 2 shows the values for the carbonate content and the pore volume of the various catalysts after tableting but before an after-calcination, after tableting and after-calcination and also after tableting, after-calcination and reduction. Reduction was carried out at 200 C. for 4 hours using 5% by volume of hydrogen in nitrogen. The pore volume was determined by the mercury intrusion method in accordance with DIN 66133. Particularly after reduction, the shaped catalyst bodies according to the invention have a higher pore volume than the comparative catalyst.

(33) TABLE-US-00002 TABLE 2 Carbonate content and pore volume Pore volume [cm.sup.3/g] Carbonate After After After content [%] tableting calcination reduction Comparative 0.15 0.2 catalyst Catalyst 1 2.3 0.13 0.24* 0.29 Catalyst 2 4.5 0.19 0.33* 0.46 Catalyst 3 6.8 0.24 0.36* 0.5 Catalyst 4 8.9 0.3 0.37* 0.52 *values correspond to the catalysts 1A to 4A

(34) The analytical data show that the carbonate content of the catalysts varies as a function of the proportion of uncalcined material.

(35) It can be seen from table 1 that the catalysts produced according to the invention have a significantly increased conversion of methyl laurate compared to the comparative catalyst. This increase could be observed at all three temperatures selected, 160 C., 180 C. and 240 C. The proportion of unreacted C12-methyl ester could be reduced to less than one fifth (from 2.9% in the case of the comparative catalyst to 0.5% in the case of catalyst 1A).

(36) In summary, it can therefore be said that an improvement in the economics, in particular an increase in the conversion to the target product, is achieved by means of the catalyst of the invention.