Hydrogenation Process

Abstract

The present invention relates to a continuous flow hydrogenation process and process apparatus.

Claims

1. A flow-type hydrogenation apparatus for performing hydrogenation, comprising a heat exchanger, a mixing vessel, one or more hydrogenation reactors, a back pressure regulator, a hydrogen source, and a mass flow controller; the mixing vessel having one or more inlet ports, wherein the or each inlet port is configured to receive therethrough a liquid and/or hydrogen from the hydrogen source, and an outlet port in fluid communication with the one or more hydrogenation reactors; the mass flow controller being located downstream of the hydrogen source and upstream of the mixing vessel; each one or more hydrogenation reactors having an inlet port in fluid communication with the mixing vessel and an outlet port; each one or more hydrogenation reactors being a packed bed reactor; wherein the heat exchanger is located downstream of the one or more hydrogenation reactors and upstream of the back pressure regulator.

2. (canceled)

3. Apparatus according to claim 1 which further comprises a pump located upstream of the mixing vessel to pump the liquid into the mixing vessel via the or one of the inlet ports.

4. (canceled)

5. Apparatus according to claim 3 wherein the mixing vessel comprises at least one of inert packing material and a heater to effect heating.

6. (canceled)

7. Apparatus according to claim 5, which further comprises a heater located upstream of the mixing vessel.

8. Apparatus according to claim 7 which further comprises a junction, having two inlet ports and an outlet port, located downstream of the mixing vessel and upstream of the one or more hydrogenation reactors; one inlet port is in fluid communication with the mixing vessel outlet port and the second inlet port is configured to receive a second liquid; the outlet port is in fluid communication with the one or more hydrogenation reactors, optionally wherein the apparatus further comprises a pump located upstream of the junction to pump the second liquid into the junction via the inlet port configured to receive a second liquid, and/or optionally wherein the apparatus further comprises a liquid reservoir in fluid communication with the inlet port configured to receive a second liquid.

9-10. (canceled)

11. Apparatus according to claim 8, which further comprises a pre-reactor heat exchanger being located between, and in fluid communication with the outlet port of the mixing vessel and the one or more hydrogenation reactors, optionally wherein the pre-reactor heat exchanger is connected to the one or more hydrogenation reactors via one or more pipes packed with inert material.

12. (canceled)

13. Apparatus according to claim 11, wherein the or each hydrogenation reactor is at least one of an adiabatic reactor and a liquid-phase hydrogen reactor.

14. (canceled)

15. Apparatus according to claim 13, wherein the or each hydrogenation reactor has a packed bed comprising catalyst particles, optionally wherein the D50 value of the catalyst particles is less than 100 m, optionally less than 50 m, and/or optionally wherein the span is less than 1; or wherein the or each packed bed hydrogenation reactor has a packed bed comprising inert particles, optionally wherein the D50 value of the inert particles is less than 100 m, optionally less than 50 m, and/or optionally wherein the span is less than 1.

16-21. (canceled)

22. Apparatus according to claim 15, which further comprises a hydrogen compressor.

23. (canceled)

24. Apparatus according to claim 22, which further comprises temperature sensors located at the inlet port and outlet port of each hydrogenation reactor to measure the temperature of the liquid composition in use.

25. Apparatus according to claim 24, which comprises two or more hydrogenation reactors, each hydrogenation reactor being located between, and in fluid communication with, the outlet port of the mixing vessel and the heat exchanger, optionally wherein the two or more hydrogenation reactors comprise a first hydrogenation reactor and a second hydrogenation reactor and optionally wherein the apparatus comprises a further heat exchanger located between, and in fluid communication with, the first and second hydrogenation reactors.

26. (canceled)

27. A continuous flow hydrogenation process comprising: i) providing a liquid composition; ii) providing hydrogen gas; iii) mixing the liquid composition with the hydrogen gas in a mixing vessel; iv) transferring the mixture of liquid composition and hydrogen to a packed bed hydrogenation reactor to effect hydrogenation; v) transferring the reacted liquid composition to a heat exchanger to effect cooling to a predetermined temperature.

28. A process according to claim 27 which further comprises the step of transferring the liquid composition to a heater to effect heating to a pre-determined mixing temperature following step (ii) prior to step (iii), and/or wherein step (iii) comprises heating and mixing the liquid composition with the hydrogen gas in the mixing vessel at a pre-determined mixing temperature.

29. (canceled)

30. A process according to claim 28 wherein the mixing vessel comprises inert packing material.

31. A process according to claim 30, which further comprises transferring the mixture of liquid composition and hydrogen at a pre-determined mixing temperature following step (iii) to a pre-reactor heat exchanger to effect cooling to a pre-determined reaction temperature prior to transferring the mixture of liquid composition and dissolved hydrogen to a packed bed hydrogenation reactor to effect hydrogenation in step (iv), optionally wherein the mixture of liquid composition and hydrogen is transferred from the pre-reactor heat exchanger to a packed bed hydrogenation reactor via a pipe packed with inert material.

32. (canceled)

33. A process according to claim 31, wherein the liquid composition comprises a starting compound to be hydrogenated, or which further comprises the steps of a) providing a second liquid composition comprising a starting compound to be hydrogenated and b) adding the second liquid composition to the mixture of liquid composition and dissolved hydrogen following step (iii) prior to step (iv).

34. (canceled)

35. A process according to claim 33 wherein the hydrogen gas is compressed to a pressure greater than 100 bar.

36. A process according to claim 35 wherein hydrogenation is effected in step (iv) in the presence of a catalyst.

37. A process according to claim 36 wherein the packed bed hydrogenation reactor has a packed bed comprising catalyst particles, optionally wherein the D50 value of the catalyst particles is less than 100 m, optionally less than 50 m, and/or optionally wherein the span is less than 1; or wherein the packed bed hydrogenation reactor has a packed bed comprising inert particles, optionally wherein the D50 value of the inert particles is less than 100 m, optionally less than 50 m, and/or optionally wherein the span is less than 1.

38-42. (canceled)

43. A process according to claim 37 wherein temperature and pressure within the packed bed hydrogenation reactor to effect hydrogenation in step (iv) is such that the liquid composition remains in the liquid phase; and/or wherein the hydrogenation in step (iv) is an adiabatic process; and/or wherein the delivery of hydrogen gas is controlled to achieve a pre-determined increase in temperature of the liquid composition as a result of hydrogenation in the packed bed reactor.

44-46. (canceled)

Description

[0273] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0274] FIG. 1 is a schematic diagram of a flow-type hydrogenation apparatus for performing hydrogenation according to the invention.

[0275] For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms upstream, and downstream refer to the position of the components as found in the apparatus in normal use defined in relation to the process flow.

[0276] A flow-type hydrogenation apparatus 1 according to the invention is shown in FIG. 1.

[0277] The flow-type hydrogenation apparatus 1 comprises a hydrogen source 20, a hydrogen compression module 30, a hydrogen delivery system 40, a liquid delivery module 50, a mixing module 60, a hydrogenation module 70 and a back pressure regulator 80. The hydrogen source 20 is in fluid communication with the hydrogen compression module 30; the hydrogen compression module 30 is in fluid communication with the hydrogen delivery module 40; the hydrogen delivery module 40 and the liquid delivery module 50 are both in fluid communication with the mixing module 60; and the mixing module 60 is in fluid communication with the hydrogenation module 70; the hydrogenation module is in fluid communication with the back pressure regulator 80.

[0278] The hydrogen compression module 30 comprises a hydrogen compressor 31 and a hydrogen reservoir 32. The supply pressure of hydrogen into the compressor 31 is controlled by a hydrogen pressure regulator 33. The supply pressure of the hydrogen from the reservoir 32 is controlled by a pressure regulator 34. The flow of the hydrogen is controlled by a one-way valve 35.

[0279] The hydrogen delivery system 40 comprises a mass flow controller 43, and a one-way valve 44 and is in fluid communication with the hydrogen reservoir 32 and the mixing module 60. The one way valve 44 allows hydrogen gas to flow when the pressure upstream of the valve is greater than the pressure downstream. As described above, it is highly desirable that hydrogen addition is well controlled in order to control the highly exothermic hydrogenation reaction and limit over-reduced impurities.

[0280] The liquid delivery module 50 comprises a liquid reservoir 51, a pump 52, and a pulse dampener 53 to provide a constant and stable flow of liquid.

[0281] The mixing module 60 comprises a heater 61 and a mixing vessel 62 which can effect mixing. The mixing vessel 62 comprises inert packing material wherein the mean particle diameter of the packing material is less than 100 m.

[0282] The hydrogenation module 70 comprises a packed bed hydrogenation reactor 71 and a heat exchanger 72

[0283] The hydrogenation reactor 71 has a packed bed comprising catalyst particles (not shown), wherein the volume mean particle diameter of the catalyst is less than 100 m. By way of example, the catalyst may be alumina supported platinum wherein the D50 value of the catalyst particles is 70 m; D10 is 45 m; D90 is 110 m.

[0284] The hydrogenation module 70 further comprises a pair of thermocouples 73 (not shown) located at the inlet port and outlet port of the hydrogenation reactor 71 to measure the temperature of the liquid composition in use.

[0285] The pump 52 pumps the liquid composition comprising the starting compound from the liquid reservoir 51 to the heater 61 where it is heated to a pre-determined mixing temperature, e.g. 200 C. with hydrogen gas delivered via the hydrogen delivery system and transferred to the mixing vessel 62. The mixture of liquid composition and hydrogen is then transferred into the packed bed hydrogenation reactor 71 to effect hydrogenation. The delivery of hydrogen gas is controlled to achieve a predetermined increase in temperature of the liquid composition as a result of hydrogenation e.g from 150 C. to 170 C. as measured by the thermocouples 73 in use. The hydrogenated liquid composition is then transferred to the heat exchanger 72 to effect cooling to a pre-determined temperature, e.g. 40 C. The hydrogenated liquid composition then passes through the back pressure regulator valve 80 before collection

[0286] The skilled person will appreciate that further hydrogenation reactors may be added to the embodiment described hereinabove. Provided that the process of reacting the partially hydrogenated liquid composition in a further hydrogenation reactor and then cooling in a further heat exchanger is followed, any number of hydrogenation reactors could theoretically be added.