METHOD AND APPARATUS FOR PERFORMING A CHEMICAL REACTION UNDER ELEVATED PRESSURE

Abstract

The invention relates to a method of performing a chemical reaction under elevated pressure. It is suggested that the method comprises the steps of pressurizing a first vessel (3) and a second vessel (5) with reactant-containing liquid and gas to a predetermined pressure, providing reaction conditions in one of the vessels (3, 5) such that the chemical reaction is effected and a product-containing liquid is obtained, withdrawing liquid from the respective vessel (3, 5) as reaction product when a predetermined amount of reaction product has formed, preferably after the chemical reaction in the respective vessel (3, 5) has concluded, and synchronously supplying reactant-containing liquid to the respective other vessel (3, 5), wherein the first and second vessels (3, 5) are in fluid communication by way of a gas communication passage (27). The invention also relates to an apparatus and use thereof for performing said chemical reaction.

Claims

1. A method of performing a chemical reaction under elevated pressure, the method comprising: pressurizing a first vessel and a second vessel with i) reactant-containing liquid and ii) gas to a predetermined pressure, providing reaction conditions in one of the first vessel and the second vessel such that the chemical reaction is effected and a product-containing liquid is obtained, withdrawing the product-containing liquid from the respective vessel when a predetermined amount of product has been produced, and simultaneously supplying reactant-containing liquid to the respective other vessel, wherein the first vessel and the second vessel are in fluid communication by way of a gas communication passage.

2. The method of claim 1, wherein withdrawing the product-containing liquid is effected at a predetermined withdrawal flow rate, and supplying the reactant-containing liquid is effected at a predetermined feed flow rate, the feed flow rate being substantially equal to the withdrawal flow rate.

3. The method of claim 1, wherein providing reaction conditions such that the chemical reaction is effected and a product-containing liquid is obtained is performed in the second vessel, and the method further comprises: supplying reactant-containing liquid from the first vessel to the second vessel after withdrawing the product-containing liquid from the second vessel.

4. The method of claim 3, wherein supplying the reactant-containing liquid from the first vessel to the second vessel is effected by gravity.

5. The method of claim 3, wherein supplying the reactant-containing liquid from the first vessel to the second vessel is effected by or assisted by a fluid conveying device.

6. The method of claim 1, wherein providing reaction conditions such that the chemical reaction is effected and a product-containing liquid is obtained is alternatingly performed in both the first vessel and the second vessel.

7. The method of any ene of claim 1, wherein the gas comprises a reactant-containing gas comprising at least one of: carbon monoxide for effecting a carbonylation reaction, or hydrogen for effecting a hydroformylation or hydrogenation reaction.

8. The method of claim 1, wherein the reactant-containing liquid comprises an alcohol.

9. The method of claim 1, further comprising: determining if the pressure in the first vessel and the second vessel drops below the predetermined pressure, and replenishing gas to the first vessel and the second vessel until the predetermined pressure is reached again.

10. The method of claim 1, wherein after the predetermined amount of product has been produced in the respective vessel, the respective vessel contains several liquid phases, and the method further comprises: separately withdrawing a select liquid phase or phases from the respective vessel.

11. The method of claim 7, wherein the reactant-containing liquid, the gas and the reaction conditions are selected such that a carbonylation reaction is performed.

12. The method of claim 1, wherein the reaction is effected in the presence of a catalyst.

13. The method of claim 1, wherein the reactant-containing liquid, the gas and the reaction conditions are selected such that a carbonylation product, a hydrogenation product or a hydroformylation product is produced.

14. An apparatus for performing a chemical reaction under elevated pressure, the apparatus comprising: a first vessel that is configured to be pressurized with liquid and gas at a predetermined pressure and comprises at least one liquid inlet configured for receiving pressurized, reactant-containing liquid, and a liquid outlet for withdrawing liquid from the first vessel, and a second vessel that is configured to be pressurized with liquid and gas at a predetermined pressure and comprises at least one liquid inlet for receiving reactant-containing liquid, and a liquid outlet for withdrawing liquid from the second vessel, wherein at least one of the is configured to provide reaction conditions, and the first vessel and the second vessel are connected to be in fluid communication by way of a gas communication passage.

15. The apparatus of claim 14, further comprising: a pump upstream of the liquid inlet of the first vessel and the second vessel, the pump being configured to transport liquid at a predetermined flow rate.

16. The apparatus of claim 15, wherein the pump is a first pump and the apparatus further comprises a second pump downstream of the liquid outlet of the second vessel (5), the first pump and the second pump being configured to simultaneously transport liquid at a predetermined flow rate.

17. The apparatus of claim 15, wherein the first vessel is a buffer vessel and the second vessel is a reactor vessel, and the liquid outlet of the first vessel is connected to be in fluid communication with the liquid inlet of the second vessel.

18. The apparatus of claim 14, wherein the liquid outlet of the first vessel is positioned above the liquid inlet of the second vessel.

19. The apparatus of claim 14, wherein the first vessel and the second vessel both are reactor vessels.

20. The apparatus (1″, 1″′) of claim 19, wherein the liquid inlet of the first vessel and the liquid inlet of the second vessel are connected to an inlet manifold, and the liquid outlet of the first vessel and the liquid outlet of the second vessel are connected to an outlet manifold.

21. The apparatus of claim 20, further comprising: a first pump arranged upstream of the inlet manifold, and a second pump arranged downstream of the outlet manifold.

22. The apparatus of claim 19, further comprising: an inlet valve associated with each liquid inlet of the first vessel and the second vessel, and an outlet valve associated with each liquid outlet of the first vessel and the second vessel.

23. The apparatus of claim 22, wherein the inlet valve of the first vessel is configured to open and close synchronously with the outlet valve of the second vessel, and the inlet valve of the second vessel is configured to open and close synchronously with the outlet valve of the first vessel.

24. The apparatus of claim 14, further comprising: a dip tube associated with the liquid outlet of at least one of the first vessel and the second vessel, wherein the dip tube extends downwards into the respective vessel to a predetermined depth.

25. The apparatus of claim 14, wherein at least one of the first vessel and the second vessel comprises a gas inlet for receiving pressurized gas from a gas source.

26. The apparatus of claim 15, further comprising: a control device that is operatively coupled with the pump and configured to synchronize the feed flow rate of liquid introduced into the first vessel with the withdrawal flow rate of liquid withdrawn from the second vessel, and the feed flow rate of liquid introduced into the second vessel with the withdrawal flow rate of liquid withdrawn from the first vessel.

27. The apparatus of claim 26, wherein the control device is configured to carry out the method of claim 1.

28. A method for performing a chemical reaction, the method comprising: producing a carbonylation product, a hydrogenation product or a hydroformylation product with the apparatus of claim 14.

Description

[0079] Herein,

[0080] FIG. 1: apparatus for performing a chemical reaction according to a first embodiment,

[0081] FIG. 2: apparatus similar to the FIG. 1 in a second embodiment,

[0082] FIG. 3: apparatus or performing a chemical reaction on the elevated pressure according to a third embodiment, and

[0083] FIG. 4: apparatus similar to FIG. 3 in a fourth embodiment.

[0084] When describing the preferred embodiments, functionally or structurally identical elements have identical reference signs across the embodiments. It shall be understood that some features are only shown with respect one or a select number of embodiments while being omitted in the remaining embodiment or embodiments. However, the description of the preferred embodiments is to be understood in context with the description hereinabove. Embodiments of one figure can be combined with embodiments of other figures as far as they are covered by the above description and claimed subject-matter.

[0085] FIG. 1 shows an apparatus 1 for performing a chemical reaction under elevated pressure. The apparatus 1 is particularly designed for performing a carbonylation reaction of isobutylphenylethanol as a reactant-containing liquid and carbon monoxide as a reactant-containing gas. The apparatus 1 comprises a first vessel 3 and a second vessel 5. Both vessels 3, 5 are configured to receive pressurized liquid and gas at a predetermined pressure of for example 90 bar or above, preferably 150 bar and above.

[0086] The first vessel 3 comprises a liquid inlet 7 and a liquid outlet 9 positioned at respectively suitable portions of the first vessel 3. Exemplarily but not exclusively, the liquid inlet 7 is shown in an upper portion of the first vessel 3 while the outlet is shown in a lower portion of the first vessel 3. Further, the first vessel 3 comprises a gas port 11 connecting to the first vessel 3. Likewise, the gas port 11 is positioned suitably on the first vessel 3 and is exemplarily but not exclusively shown as positioned in the upper region of the vessel to avoid inadvertent liquid transfer through the gas port 11.

[0087] Inside the first vessel 3, a gas volume 13 extends above a liquid volume 15.

[0088] The second vessel 5 comprises a liquid inlet 17 and a liquid outlet 19, each positioned at a respective suitable position on the second vessel 5. Further, the second vessel 5 comprises a gas port 21. Inside the second vessel 5, a gas volume 23 extends above a liquid volume 25.

[0089] The gas ports 11, 21 of the first and second vessels 3, 5 are interconnected by a gas communication passage 27 such that the gas volumes 13, 23 may communicate freely with one another. The gas communication passage 27 optionally comprises a valve 29 which, however, normally is closed throughout the chemical reaction and open while filling and withdrawing from the vessels to allow free gas communication as well as while transferring the starting material from the buffer tank to the reactor. The valve 29 may also be closed for installation, deinstallation and maintenance purposes. If the first and second vessels 3, 5, and the type of reaction to be performed allow for the valve 29 to be open, the valve 29 does not need to be closed during the reaction. Having the valve 29 open during the reaction facilitates efforts to maintain a constant pressure inside both vessels 3, 5 by only having to feed pressurized gas to one of the vessels 3, 5 instead of both.

[0090] The liquid outlet 9 of the first vessel 3 is interconnected with the liquid inlet 17 of the second vessel 5 to be in fluid communication with one another. Interposed between the liquid outlet 9 and the liquid inlet 17 is a valve 14, which preferably is a control valve. The first and second vessels 3, 5 are connected by way of a liquid communication passage 16.

[0091] Upstream of the first vessel 3, a first pump 31 is associated with the liquid inlet 7 and configured to supply reactant-containing liquid from a source 35 thereof. Downstream of the second vessel 5, a second pump 33 is optionally connected with the liquid outlet 19 and configured to withdraw liquid from the second vessel 5. Said second pump 33 is particularly beneficial for performing reactions at the lower end of the inventive ranges of elevated pressure, e.g. at pressures below 4 MPa. For higher pressures, e.g. in the range of 9 MPa and above, the second pump can be omitted since the pressure inside the vessels 3,5 is sufficient for driving the liquid through the respective outlets.

[0092] In operation, liquid and gas communication between the first and second vessels 3, 5 occurs in the manner described below. Firstly, pressurized reactant-containing liquid and gas is supplied to the second vessel 5 which is a reactor vessel. The second vessel 5 is then operated by providing reaction conditions in the second vessel 5 such that the chemical reaction, which preferably is a carbonylation reaction, is effected in the second vessel 5, and a product-containing liquid is contained, the reaction product preferably being isobutylphenyl propionic acid. The chemical reaction is generally known in the art, and reference is made to the comments hereinabove.

[0093] After a predetermined amount of reaction product has formed, preferably when the reaction has concluded, in the second vessel 5, product-containing liquid has formed in the liquid volume 25 in the second vessel 5. The product-containing liquid is withdrawn through liquid outlet 19, optionally assisted by operating the second pump 33. Synchronously, the first pump 31 is actuated to supply new reactant-containing liquid to the first vessel 3 such that the sum of the liquid volume 15 in the first vessel 3 and the liquid volume 25 in the second vessel 5 remains substantially constant. This is achieved substantially isobarically by allowing the gas volumes 13, 23 in the first and second vessels 3, 5 to communicate freely through gas communication passage without pressure loss. In order to achieve isobaric conditions as closely as possible, preferably supplemental pressurized gas is fed to the vessels 3, 5 such as to compensate for solubility losses and gas consumed by the reaction itself, if any.

[0094] During this stage, the valve 14 is preferably maintained in a closed position. After the liquid transfers out of the second vessel 5 and into the first vessel 3 have respectively concluded, the liquid volume 15 in the first vessel 3 will be large while the liquid volume 25 in the second vessel 5 will be low. By now opening valve 14, and preferably closing liquid inlets 7 and 19, the second vessel 5 is replenished with reactant-containing liquid from the first vessel 3 through the liquid communication passage 16. Simultaneously, gas may flow freely between the gas volumes 13, 23 such that constant pressure is maintained within the system of the two vessels 3, 5. The liquid movement is indicated by arrows P.sub.1 and P.sub.2 during the liquid transfer phase. During that phase, gas flows in the direction of arrow P.sub.4. In the ensuing phase, when liquid is transferred from the first vessel 3 to the second vessel 5 in the direction of arrow P.sub.3, gas flows in the direction of arrow P.sub.5.

[0095] Particularly preferred, the apparatus 1 comprises a control device 37 which is in signal communication with the first pump 31 and the optional second pump 33, or with optional control valves associated with the respective inlets and outlets of the vessels 3, 5 (control valves not shown) and preferably also with the valve 14 in order to administer the operation of the first and second pumps 31, 33 and, if necessary, the valve 14 to carry out the method described hereinabove.

[0096] FIG. 2 shows a modified apparatus 1′ for performing a chemical reaction under elevated pressure. The apparatus 1′ is structurally and systematically very similar to apparatus 1 shown in FIG. 1. Apparatus 1′ may also comprise a control device 37 in the manner shown in FIG. 1 which, however, has been omitted from FIG. 2 for ease of legibility. The apparatus 1′ differs from the apparatus 1 shown in FIG. 1 in that the second vessel 5 comprises a dip tube 39 that is connected to the liquid outlet 19 of the second vessel 5 and extends into the second vessel 5 to a predetermined depth. This setup is considered particularly beneficial whenever the reaction product contains multiple liquid phases, and thus the liquid volume inside the second vessel is split into volume portions 25a, b. With the dip tube 39, it is possible to selectively remove only a desired liquid phase or number of liquid phases from the second vessel 5. This is particularly advantageous when the reaction-product is not equally distributed among all liquid phases, but predominantly or exclusively resides within one liquid phase or a select number of liquid phases. It shall be understood that while not explicitly shown, also the apparatus of FIG. 1 may comprise a dip tube connected to the corresponding liquid outlet of the second vessel 5.

[0097] The operation is however essentially identical to the operation of the apparatus 1 shown in FIG. 1.

[0098] While the embodiments shown in FIGS. 1 and 2 relate to an apparatus having one reactor vessel, namely the second vessel 5, and one buffer vessel, namely the first vessel 3, the embodiments shown in FIGS. 3 and 4 have a slightly deviating functional principle. The apparatus 1″ shown in FIG. 3 and the apparatus 1″′ shown in FIG. 4 comprise two reactor vessels 3, 5, respectively. In other words, in addition to the second vessel 5, also the first vessel 3 is a reactor vessel. The two vessels 3, 5 are operated alternatingly. An efficient liquid supply is achieved by providing a liquid manifold 47 to which both inlets 7, 17 of the first vessel 3 and second vessel 5 are connected. Similarly, the outlets 9, 19 of the first and second vessels 3, 5 are connected to a liquid outlet manifold 49.

[0099] The apparatus 1″ and 1″′ respectively comprise a dedicated gas inlet suitably positioned and connected to the gas ports 11, 21 associated with the first and second vessels 3, 5. The gas ports 11, 21 are thus also configured to receive pressurized gas, preferably reactant-containing gas from a source 45 of said gas.

[0100] The liquid inlet 7 of the first vessel 3 is associated with a valve 8, preferably a control valve. The liquid inlet 17 of the second valve 5 is associated with a valve, preferably control valve 18.

[0101] Both liquid outlets 9, 19 are associated with an outlet valve arrangement 20, which may, as depicted, be formed as a manifold valve or an assembly of multiple separate valves.

[0102] In operation, one of the two vessels 3, 5, for example the first vessel 3 is initially supplied with pressurized reactant-containing liquid and gas depending on the size of the vessels 3, 5, also the second vessel 3, 5 is provided with some pressurized liquid but mainly with gas. The amount of the reactant-containing liquid in the second vessel 5 will initially be lower than in the first vessel 3.

[0103] Subsequently, reaction conditions are provided in the first vessel 3 and the reaction, preferably a carbonylation reaction, hydrogenation reaction or hydroformylation reaction as mentioned herein above, is effected. After a predetermined amount of reaction product has formed, preferably when the reaction has concluded, the outlet valve 20 is operated such that liquid may be withdrawn from the first vessel 3 and simultaneously, the inlet valve 18 associated with the liquid inlet 17 of the second vessel 5 is opened such that liquid may flow in the direction of arrow P.sub.8 into the second vessel 5. This is preferably achieved by operating the first and second pumps 31, 33, respectively. The flow rate provided by the first and second pumps preferably is such that the amount of liquid withdrawn from the first vessel 3 is equal to the amount of liquid supplied to the second vessel 5. After replenishing the second vessel 5 with reactant-containing liquid, the necessary amount of pressurized gas is resupplied until the pressure inside the gas volume 13, 23 maintains a predetermined level. This may also occur continuously during the operation of the apparatus 1″, 1″′.

[0104] While liquid is withdrawn from the first vessel 3 and supplied to the second vessel 5, gas flows in the direction of arrow P.sub.10.

[0105] Next, the second vessel 5 is ready for performing the chemical reaction. After a predetermined amount of reaction product has formed, preferably when the reaction has concluded, in the second vessel 5, a liquid exchange is performed by withdrawing product-containing liquid from the second vessel 5 in the direction of arrow P.sub.7, and supplying reactant-containing liquid in the direction in arrow P.sub.6 to the first vessel 3 again by operating the first and second pumps 31, 33 and switching the valves 8, 20 correspondingly.

[0106] The embodiment of apparatus 1″′ shown in FIG. 4 is structurally and systematically similar to the apparatus 1″ shown in FIG. 3, with the exception of both vessels 3, 5 being shown as containing multiple liquid phases after a predetermined amount of reaction product has formed, preferably when the reaction has concluded. Similar to the operation of FIG. 2, both vessels 3, 5 comprise dip tubes 39, 40 associated with the respective liquid outlet 9, 19 of the vessels 3, 5 which extend into the vessel to a predetermined depth which allows for selectively removing the desired liquid phase or phases. It shall be understood that while not explicitly shown, also the apparatus 1″ of FIG. 3 may comprise a dip tube connected to the corresponding liquid outlet of the second vessel.

[0107] Generally for all embodiments making use of a dip tube in the reactor vessel, it shall be understood that the second vessel may comprise one or more additional liquid outlets to withdraw material from the vessel that is not extracted through the respective dip tube which are not shown in an effort to keep the drawings easily legible. If for example, the dip tube is used to extract only a desired phase or portion of material from the reactor vessel, the remaining material will eventually be withdrawn through the suitably positioned additional liquid outlet or outlets.

[0108] The preferred embodiments shown in FIGS. 1 to 4 relate to an apparatus 1, 1′, 1″, 1″′ having a first vessel 3 and a second vessel 5. The invention is, however, not limited to operating exclusively two vessels. Likewise, it is within the scope of the invention to operate an apparatus having more than two vessels while still adhering to the general teaching shown in the embodiments described hereinabove. Insofar, mentioning a plurality of objects does not exclude an apparatus comprising more than those objects.