METHOD FOR THE PREPARATION OF C3-C12-ALCOHOLS BY CATALYTIC HYDROGENATION OF THE CORRESPONDING ALDEHYDES

Abstract

The present invention relates to a process for preparing C.sub.3-C.sub.12 alcohols by catalytically hydrogenating the corresponding aldehydes at a temperature in the range of 50-250 C. and a pressure in the range of 5-150 bar in the presence of a supported activated Raney-type catalyst, characterized in that the support body is a metal foam and the metal is selected from the group consisting of cobalt, nickel and copper and mixtures thereof.

Claims

1-12. (canceled)

13. A process for preparing C.sub.3-C.sub.12 alcohols by catalytically hydrogenating the corresponding aldehydes at a temperature in the range of 50-250 C. and a pressure in the range of 5-150 bar in the presence of a supported activated Raney-type catalyst, wherein the supported activated Raney-type catalyst comprises a support body that is a metal foam and the metal is selected from the group consisting of: cobalt; nickel; copper; and mixtures thereof.

14. The process of claim 13, wherein a C.sub.3-C.sub.9 aldehyde is used in the hydrogenation.

15. The process of claim 13, wherein isononanal or butyraldehyde is used as the aldehyde in the hydrogenation.

16. The process of claim 13, wherein the metal is nickel.

17. The process of claim 13, wherein the supported activated Raney-type catalyst contains 85-95% by weight of nickel and 5-15% by weight of aluminium, based on the total weight of the catalyst.

18. The process of claim 17, wherein the supported activated Raney-type catalyst additionally contains up to 3% by weight of molybdenum, based on the total weight of the catalyst.

19. The process of claim 13, wherein the supported activated Raney-type catalyst has the following properties: a) a BET surface area of 1-200 m.sup.2/g, and b) macroscopic pores in the range of 100-5000 m.

20. The process of claim 13, wherein the supported activated Raney-type catalyst is cylindrical, annular, cuboidal, parallelepipedal or cubic.

21. The process of claim 20, wherein the supported activated Raney-type catalyst is used in the form of a fixed bed of bulk material.

22. The process of claim 21, wherein the supported activated Raney-type catalyst is cuboidal and has a maximum edge length of 50 mm.

23. The process of claim 13, wherein the hydrogenation is conducted continuously.

24. The process of claim 13, wherein the aldehyde is obtained by an oxo process.

25. The process of claim 17, wherein the supported activated Raney-type catalyst has the following properties: a) a BET surface area of 1-200 m.sup.2/g, and b) macroscopic pores in the range of 100-5000 m.

26. The process of claim 25, wherein the supported activated Raney-type catalyst is cylindrical, annular, cuboidal, parallelepipedal or cubic.

27. The process of claim 26, wherein the supported activated Raney-type catalyst is used in the form of a fixed bed of bulk material.

28. The process of claim 27, wherein the supported activated Raney-type catalyst is cuboidal and has a maximum edge length of 50 mm.

29. The process of claim 25, wherein the hydrogenation is conducted continuously.

30. The process of claim 25, wherein the aldehyde is obtained by an oxo process.

31. The process of claim 25, wherein a C.sub.3-C.sub.9 aldehyde is used in the hydrogenation.

32. The process of claim 25, wherein isononanal or butyraldehyde is used as the aldehyde in the hydrogenation.

Description

EXAMPLES

Abbreviations

[0026] [00001]$\mathrm{INAL}=\mathrm{isononanal}$$\mathrm{INA}=\mathrm{isononanol}$$\mathrm{WHSV}=\mathrm{Weight}.Math..Math.\mathrm{Hourly}.Math..Math.\mathrm{Space}.Math..Math.\mathrm{Velocity}.Math..Math.\left(\frac{{\stackrel{.}{m}}_{\mathrm{reactant}}}{m_{\mathrm{cat}}}\right)$$\mathrm{LHSV}=\mathrm{Liquid}.Math..Math.\mathrm{Hourly}.Math..Math.\mathrm{Space}.Math..Math.\mathrm{Velocity}.Math..Math.\left(\frac{{\stackrel{.}{V}}_{\mathrm{liquid}}}{V_{\mathrm{cat}}}\right)$$X\left(\mathrm{INAL}\right)=\mathrm{conversion}.Math..Math.\mathrm{of}.Math..Math.\mathrm{isononanal}$$S\left(\mathrm{INA}\right)=\mathrm{selectivity}.Math..Math.\mathrm{for}.Math..Math.\mathrm{isononanol}$

[0027] Preparation of Catalysts:

[0028] Catalyst 1 (Supported Activated Nickel Foam)

[0029] A nickel foam commercially available as roll material and having a thickness of 1.9 mm, a width of 300 mm and an average pore size of 580 m was sprayed with a commercially available polyethyleneimine adhesion promoter solution, coated with likewise commercially available aluminium powder having a particle size <63 m (d.sub.5040 m), and subjected to a heat treatment with exclusion of oxygen at 725 C. The mass ratios of nickel foam used and aluminium powder were chosen here such that the ratio of aluminium to the total mass of the supported alloy was 282%. After cooling, the material was comminuted with a laser into cuboidal particles having an edge length of 441.9 mm. The resulting bulk material was activated by treatment in a 10% by weight sodium hydroxide solution at 60 C. for 60 minutes. Subsequently, the catalyst was washed with demineralized water until a pH of <10 had been attained.

[0030] Catalyst 2 (Molybdenum-Doped)

[0031] 2.24 g of MoO.sub.3 were dissolved in 100 ml of boiling demineralized water by gradual addition of 1.48 g of Na.sub.2CO.sub.3. Once the MoO.sub.3 had dissolved, the solution was made up to 150 ml.

[0032] 160 g of supported activated nickel foam in water were washed with ammonium chloride solution until a pH of the supernatant solution of 7.5-8 had been attained. Then the catalyst was impregnated with the molybdate solution at 40 C. until no molybdenum was detectable any longer in the solution with Merckoquant or Quantofix test strips. Subsequently, the catalyst was washed twice with demineralized water.

[0033] The composition of catalysts 1 and 2 was analysed by ICP-OES; the results are reported in Table 1 below.

TABLE-US-00001 TABLE 1 Catalyst 1 Catalyst 2 Nickel (% by wt.) 88 87 Aluminium (% by wt.) 11 11.3 Molybdenum (% by wt.) 0.74 Bulk material (mm) 4*4*1.9 4*4*1.9

Use Example 1 (Inventive)Hydrogenation of Isononanal Over Catalyst 1 or Catalyst 2

[0034] In a first experiment, catalyst 1 was positioned in a circulation reactor (cf. FIG. 2) in the form of a fixed bed of bulk material. At a constant hydrogen pressure of 25 bar, the reactor was supplied continuously with isononanal, with a simultaneous circulation flow rate of 25 l/h through the fixed bed and establishment of an H.sub.2 offgas rate of 5 l/h. Further reaction parameters can be found in Table 2. The reaction conditions were chosen such that, in the continuous operation established, isononanal conversion rates of 97.5% were achieved.

[0035] The experiment was repeated with catalyst 2.

Use Example 2 (Comparative Experiment)Hydrogenation of Isononanal Over Specialyst 103

[0036] The experiment described in Use example 1 was repeated with the comparative catalyst Specialyst 103 from Evonik Industries (catalyst 3). The detailed experimental conditions can be found in Table 2. The preparation, composition and structure of Specialyst 103 are disclosed in EP 3 037 400 B1 (cf. in particular paragraphs 0024 and 0027 therein).

TABLE-US-00002 TABLE 2 Catalyst 1 Catalyst 2 Catalyst 3 Pressure [bar] 25 Circulation flow rate 25 [l/h] H.sub.2 offgas [l/h] 5 Temperature [ C.] 150 170 150 170 150 180 INAL feed (l/h) 0.76 1.5 0.76 1.5 0.76 0.76 WHSV [h.sup.1] 8 15 8 15 4 5.5 LHSV [h.sup.1] 4 8 4 8 3.5 4 X (INAL) 98 98.5 98.5 98.6 94 97.6 S (INA) 102 102 102.6 102 ~102

[0037] Since the experiments were run at the same conversion (X(INAL)97.5%), the following can be inferred from the results:

[0038] With catalyst 3 (comparative experiment), the target conversion is achieved under the reaction conditions chosen with a temperature of 180 C.

[0039] At a load of 760 ml/h, both catalyst 1 and catalyst 2 already reach this target conversion at a temperature of 150 C.

[0040] At a load of 1500 ml/h, both catalyst 1 and catalyst 2 already reach this target conversion at a temperature of 170 C.

[0041] The supported activated Raney-type catalysts have a much higher activity than the comparative catalyst based on the catalyst volume. These catalysts reach identical conversions to the catalyst according to prior art even when the amount of the INAL reactant metered in is doubled. Given the same reactor size, doubling of the production volume per unit time is thus possible.

[0042] The crucial advantage of the supported activated Raney-type catalysts over the comparative catalyst is the fact that comparable conversions and yields can be achieved at much lower temperature. It is known from the thesis by Arne Reinsdorf (Deaktivierung heterogener Katalysatoren zu Hydrierung von Oxo-Alkoholen; Thesis 2017, University of Bayreuth, Arne Reinsdorf, Shaker Verlag) that the reaction temperature in particular has a great influence on the formation of high-boiling oligomers. These oligomers in turn are responsible for catalyst fouling and resultant limitations on service life. The use of supported activated Raney-type catalysts in the process according to the invention enables lowering of the reaction temperature without production losses. The lowering of the operating temperature results in a decline in aldol condensation reactions that can result in high-boiling oligomers. It is to be expected that a production plant which is operated by the process according to the invention will achieve higher production outputs with simultaneously elevated service life of the catalysts and hence will work in a more energy- and resource-efficient manner than production plants according to the prior art.

Use Example 3 (Inventive)Hydrogenation of Butyraldehyde

[0043] In a stirred tank autoclave having a volume of 0.65 l, catalyst 1 (volume: 5 ml) is positioned in a catalyst basket having an internal volume of 7 ml directly above the stirrer unit at a distance of 5 mm from the reactor wall, such that the catalyst is arranged optimally in the sparging zone of the reactor. Before the start of the reaction, butyraldehyde is pumped into the reactor in water as solvent, heated to 100 C. while stirring at 100 rpm and pressurized to 80 bar with hydrogen. The reaction was started by increasing the stirrer speed to 1000 rpm. The reaction was stopped once no significant absorption of hydrogen per unit time was observed any longer. The reaction mixture was cooled down to 40 C. and the reactor was emptied. Further reaction conditions and the conversion of butyraldehyde to 1-butanol achieved are reported in Table 3.

TABLE-US-00003 TABLE 3 Catalyst 1 Hydrogen pressure [bar] 80 Temperature [ C.] 100 LHSV [h.sup.1] 2.6 Conversion 98.3

[0044] This experiment shows that the process according to the invention can also be used to hydrogenate other aldehydes, such as butyraldehyde here, with good results in conversion and yield.

[0045] The process according to the invention thus has the following advantages resulting from the use of supported activated Raney-type catalysts: [0046] Broad field of use, suitable for all C.sub.3-C.sub.12 aldehydes [0047] No activation with alkali in the reactor necessary [0048] Allows lower reaction temperature (costs) [0049] Reduces formation of thermal by-products [0050] Mechanically stable (no abrasion in filling or operation) [0051] Very low pressure drop