PROCESS FOR CONTINUOUS HYDROGENATION OR HYDROGENATING AMINATION

• US 20120232267A1
• Filed: 03/19/2012
• Published: 09/13/2012
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Hoffer, Bram Willem, Voss, Hartwig, Schwab, Ekkehard, Rheude, Udo, Kaibel, Gerd, Haake, Mathias, Eberhardt, Jan, Karcher, Michael
• Granted Patent: US 8,557,985 B2
• Time in Patent Office: Days
• US Class Current: 544/178
• CPC Class Codes: C07C 45/62 by hydrogenation of carbon-to-carbon double or triple bonds
• CPC Class Codes: C07C 47/02 Saturated compounds having —CHO groups bound to acyclic carbon atoms or to hydrogen
• CPC Class Codes: C07C 47/228 containing six-membered aromatic rings, e.g. phenylacetaldehyde
• CPC Class Codes: C07C 49/04 Saturated compounds containing keto groups bound to acyclic carbon atoms

Abstract

A process continuously hydrogenating unsaturated compounds, in which particles of a first hydrogenation catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved, the liquid phase, in the presence of a hydrogenous gas at a first partial hydrogen pressure and at a first temperature, is conducted through a packed bubble column reactor in cocurrent counter to the direction of gravity, the effluent from the bubble column reactor is sent to a gas-liquid separation, the liquid phase is sent to a crossfiltration to obtain a retentate and a filtrate, the retentate is recycled into the bubble column reactor and the filtrate, in the presence of a hydrogenous gas at a second partial hydrogen pressure and at a second temperature, is passed over a bed of a second hydrogenation catalyst, the second partial hydrogen pressure is at least 10 bar higher than the first partial hydrogen pressure.

Claims

1-21. -21. (canceled)

22. A process for continuously hydrogenating unsaturated compounds, in which

a) particles of a first hydrogenation catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved,

b) the liquid phase, in the presence of a hydrogenous gas at a first partial hydrogen pressure and at a first temperature, is conducted through a packed bubble column reactor in cocurrent counter to the direction of gravity,

c) the effluent from the bubble column reactor is sent to a gas-liquid separation,

d) the liquid phase from step c) is sent to a crossfiltration to obtain a retentate and a filtrate,

e) the retentate is recycled into step b),

f) the filtrate, in the presence of a hydrogenous gas at a second partial hydrogen pressure and at a second temperature, is passed over a bed of a second hydrogenation catalyst,

wherein the unsaturated compound is an enamine.

23. The process according to claim 22, wherein the liquid phase is conducted through the packed bubble column reactor in step b) at a superficial velocity of at least 100 m³/m²h.

24. The process according to claim 22, wherein, in step f), the filtrate is introduced at the top of a fixed bed reactor and the filtrate trickles over the bed of the second hydrogenation catalyst under the influence of gravity.

25. The process according to claim 22, wherein, in step f), the filtrate is passed through the bed of the second hydrogenation catalyst counter to the direction of gravity.

26. The process according to claim 22, wherein the second partial hydrogen pressure is at least 10 bar higher than the first partial hydrogen pressure.

27. The process according to claim 22, wherein the first partial hydrogen pressure is from 1 to 100 bar.

28. The process according to claim 22, wherein the second partial hydrogen pressure is from 15 to 130 bar.

29. The process according to claim 22, wherein the second temperature is at least 10°

C. higher than the first temperature.

30. The process according to claim 22, wherein the first temperature is from 25 to 150°

C.

31. The process according to claim 22, wherein the second temperature is from 50 to 250°

C.

32. The process according to claim 22, wherein the enamine is prepared in situ from a carbonyl compound and a primary or secondary amine.

33. The process according to claim 32, wherein the carbonyl compound is 2-methyl-3-(p-tert-butylphenyl)propanal.

34. The process according to claim 33, wherein the amine is cis-2,6-dimethylmorpholine.

35. The process according to claim 22, wherein the liquid phase comprises substantially no external solvent or diluent.

36. The process according to claim 22, wherein the liquid phase comprises an external solvent or diluent.

37. The process according to claim 22, wherein the first hydrogenation catalyst comprises palladium on a carbon support.

38. The process according to claim 22, wherein the second hydrogenation catalyst comprises palladium on an alumina support.