WO2003047744A1

WO2003047744A1 - Reaction vessel containing a liner

Info

Publication number: WO2003047744A1
Application number: PCT/EP2002/013894
Authority: WO
Inventors: Anton John Nagy; Bashir Husein Harji
Original assignee: Avantium International B.V.
Priority date: 2001-12-07
Filing date: 2002-12-06
Publication date: 2003-06-12
Also published as: AU2002361025A1

Abstract

A reaction vessel (1) for conducting a reaction involving one or more reactants. The reaction vessel comprises a pressure resistant outer vessel (2), said outer vessel having an inner wall, and a liner (3) which is removable contained within the outer vessel and which lines the inner wall of the outer vessel and thereby avoids contact between the inner wall of the outer vessel and the one or more reactants. A space is present between the outer vessel and the liner. The liner is chemically inert and resistant to the one or more reactants to be contained inside the liner and the liner has at least one opening in communication with the inside of the liner. The reaction vessel further comprises a sealing means (5) arranged near the opening (4) of the liner and sealing the space between the outer vessel and the liner from the inside of the liner at least as the pressure difference across the sealing means is below a threshold pressure difference.

Description

REACTION VESSEL CONTAINING A LINER

The invention relates to a reaction vessel for conducting a reaction involving one or more reactants, said reaction vessel comprising:

- a pressure resistant outer vessel, said outer vessel having an inner wall;

- a liner which is removable contained within the outer vessel and which lines the inner wall of the outer vessel and thereby avoids contact between the inner wall of the outer vessel and the one or more reactants, wherein a space is present between the outer vessel and the liner, the liner being chemically inert and resistant to the one or more reactants to be contained inside the liner and the liner having at least one opening in communication with the inside of the liner. Reaction vessels of the above kind are known from practice, e.g. from US 6 132 686. In this prior art document a chemically resistant liner is used to avoid contamination of the inside of the pressure resistant outer vessel. The liner contains the liquid reactant(s) and is itself contained inside the outer vessel. The liner with its contents may be quickly removed, if desired, and replaced by an other liner, without the necessity of cleaning the outer vessel.

In order to place and remove the liner a space is present between the liner and the outer vessel. As in US 6 132 686 the liner is made of a brittle material and as a high pressure gas is introduced into the reaction vessel in the course of the reaction, provision is made for a pathway between the inside of the liner and the space between the liner and the outer vessel. Hereby a pressure equilibrium is effected on both side of the liner, which prevents the liner from breaking. A problem resulting from the reaction vessel disclosed in US 6 132 686 is that, especially when the reaction vessel is used at elevated temperatures and pressures, the one or more reactants held in the liner produce vapour which may leave the liner via the opening in the liner and enter the space between the liner and the outer vessel via said pathway. Said vapour can under circumstances already contaminate or damage the outer vessel. Also, especially when a hot reaction vessel is cooled, the vapour can condense in said space. Usually, cooling of the reactor (after reaction) is effected from outside. This results in the outer vessel walls being cooled faster than the reactant(s) contained in the liner. The decreasing temperature gradient from the reactant(s) inside the liner to the outer vessel provides a driving force for the transport of condensable vapour from the inside of the liner via the opening of the liner to the space between the liner and the outer vessel. This ultimately results in the condensation of condensable vapour in the space between liner and the outer vessel. The effect of the cooling is thus that a reactant or product in liquid form may come between the pressure resistant outer vessel and the liner, resulting in contamination, or worse, in corrosion of the pressure resistant outer vessel. Also, reactants or products may be lost.

Further, the occurrence of condensation between the liner and outer vessel is disadvantageous, as this may impair the temperature control in the reaction vessel and result in reactant and/or product loss.

Therefore it is an object of the invention to avoid the above and other problems and to provide a reaction vessel in which the occurrence of contamination and/or corrosion of the pressure resistant outer vessel can be prevented or at least minimised.

A further object of the invention is to prevent the occurrence of condensation between the liner and pressure resistant outer vessel.

The inventions achieves one or more of the above objects by providing a reaction vessel according to the preamble of claim 1, which is characterised in that the reaction vessel further comprises a sealing means arranged near the opening of the liner and sealing the space between the outer vessel and the liner from the inside of the liner at least as the pressure difference between said space and the inside of the liner is below a threshold pressure difference. The sealing means can be embodied such for a particular reaction that the pressure inside the liner does not cause a pressure difference between said space and the inside of the liner which exceeds the threshold pressure difference, either during the entire reaction or during one or more stages of the reaction.

In particular it is envisaged that the threshold pressure difference is chosen such that in a reaction wherein a vapour pressure is established by vapour produced by the one or more reactants, said vapour does not enter the space between the liner and the outer vessel.

In order to achieve the above effect is a practical if the threshold pressure difference is between 5 and 20 bar, preferably between 5 and 10 bar. This would for many reactions prevent the entry of vapour (s) into the space between the liner and the outer vessel.

Many reactions are in practice conducted at a high pressure, which pressure is commonly established by introducing a pressurised gas into the reaction vessel via a gas inlet connected to a gas source. In an embodiment wherein the threshold pressure difference would exceed the pressure difference created by the introduced high-pressure gas, the result would be a high load on the liner. In particular in case the liner is made of a brittle material, such as glass, and/or embodied with a thin wall, e.g. to promote thermal conductivity, the load could impose undesired limitations.

In a preferred embodiment of the reaction vessel it is envisaged that the threshold pressure difference is such that the high pressure gas leaks past the sealing means and enters the space between the liner and the outer vessel thereby essentially equilibrating the pressure on either side of the liner. In an example the threshold pressure difference of a particular reaction vessel is at 8 bars. If a high-pressure gas is introduced at e.g. 100 bars, some of the gas will leak past the sealing means effectively equilibrating the pressure on either side of the liner. If during the reaction vapour is formed at a vapour pressure below 8 bars, the vapour will not be able to leak past the sealing means. As in many reactions gas is used which is not detrimental to the outer vessel and/or in fact does not require any later cleaning of the outer vessel, the potentially detrimental vapours are kept away from the lined wall of the outer vessel whereas at the same time the load on the liner wall is limited.

In particular reactions it is possible that vapour (s) is produced in the reaction vessel before a high-pressure gas is introduced into the reaction vessel. The result would be that a minimal amount of the vapour flows with the gas past the sealing means and enters the space between the liner and the outer vessel. For many practical situations this will be acceptable. The embodiment disclosed above allows the use of fragile, inert liners even for high-pressure applications and prevents or at least minimises the contact of corrosive reactants/product vapours with the reactor walls.

Further, the reaction vessel prevents or at least minimises the occurrence of condensation between the liner and outer vessel.

A further advantage of the reaction vessel is that a thermal conduction enhancing substance, e.g. a paste, a liquid or a solid could be placed between the liner and the outer vessel to improve thermal conduction. The presence of the sealing means prevents any vapour produced by the thermal conduction enhancing substance from contaminating the contents of the liner.

For the pressure resistant outer vessel any suitable material may be used, providing for pressure resistance. Usually, a metal will be used such as stainless steel or aluminum. For the liner any suitable material may be used as long as the material is inert, gas tight, liquid tight and resistant to the reactants to be contained therein. Usually, the liner will be made from glass, plastic or metal, depending on the conditions and the reactants used. In most cases the reaction vessel will be operated at elevated temperatures and pressures, wherein the liner has only one opening. The person skilled in the art will however readily understand that also two or more openings may be present, if desired.

According to a preferred embodiment the sealing means are placed between the outer vessel and the liner. In this embodiment the sealing means may be O-rings. Such O-rings are not limited to a substantially circular cross-sectional form, but can have any suitable form for sealing, as will be well understood by a person skilled in the art. Further, the O-rings can be made from any suitable material such as metal or an elastomer. Instead of O-rings the sealing means may have any other suitable form known to the person skilled in the art. For example, multiple layers of tape or V-shaped metal rings may also be used.

In a possible design the outer vessel of the reaction vessel comprises a flange at or adjacent to one or more of the openings .

Herewith an easy sealing, especially of a reaction vessel having only one opening at one end, may be obtained. Also a surprisingly simple sealing of a plurality of parallel reaction vessels may be obtained. The person skilled in the art will understand that for obtaining a simple sealing of one or more reaction vessels, instead of a flange, also other means may be used. For example, the outer vessel may be provided with a threaded screw fitting, whereby the reaction vessel may be screwed into a top plate or lid.

According to a further preferred embodiment the outer vessel comprises a flange surrounding the opening for the introduction and removal of the liner, and the sealing means form an integral part of the liner, e.g. embodied as a flange on said liner, such that the sealing means also at least partially line the flange of the outer vessel. Herewith no O-rings or the like are necessary to prevent fluid from entering the space between the liner and the outer vessel. This embodiment is in particular suitable for low-pressure applications. In a possible embodiment of the above design the liner, at least the sealing means thereof, is made from a flexible material, to enable a simple sealing of the space between the liner and the outer vessel, and also to act as a seal between the flange of the outer vessel and a closure element, e.g. a cover or lid, of said outer vessel. More preferably, the flexible material is a compressible material, preferably selected from the group consisting of Teflon, PTFE, FEP, polypropylene, PET, nylon, polysulfides and other elastomers.

As the inner vessel is removable from the outer vessel one type of pressure resistant outer vessel may be used for all applications while a suitable liner may be selected and inserted into the outer vessel, depending on the conditions and reactants to be used.

In a further aspect the invention relates to an apparatus, in particular suitable for high throughput experimentation, comprising at least one reaction vessel according to the invention. Hereinafter the invention will be illustrated in more detail by a drawing. Herein shows:

Figure 1 a schematic cross-sectional view of a first embodiment of a reaction vessel according to the invention;

Figure 2 a schematic cross-sectional view of a plurality of parallel reaction vessels according to Figure 1; and

Figure 3 a schematic cross-sectional view of a second embodiment of a reaction vessel of the invention.

Figure 1 shows a schematic cross-sectional view of a reaction vessel 1 comprising a pressure resistant outer vessel 2 and an inert inner vessel or liner 3.

The liner 3 a tubular liner having a closed bottom and a single opening 4 at the top. The liner is removable contained within the outer vessel 2 and lines the inner wall of the outer vessel 2.

The inert liner 3 is designed such that it is resistant to the materials to be contained therein.

The reaction vessel 1 comprises sealing means 5, such as an O-ring, between the outer vessel 2 and the inner vessel 3, which sealing means 5 are formed here by a separate part, which surrounds the liner 3 at the height of the opening 4. Using the sealing means 5 substantially any fluid connection from the inside of the liner 3 to the space between the liner 3 and the outer vessel 2 is prevented as will be discussed below. The person skilled in the art will understand that in Fig. 1 the space between the outer vessel 2 and inner vessel 3 is greatly exaggerated. In fact the space commonly will be no more than to allow a sliding fit between the liner 3 and the outer vessel 2.

Further the reaction vessel 1 comprises a flange 6 in the vicinity of opening for introducing and removing the liner 3. Herewith an easy closing of the reaction vessel 1 may be obtained, especially when several reaction vessels 1 are used in parallel as will be illustrated in Fig. 2.

The persons skilled in the art will readily understand that other or additional sealing means 5 may be provided.

As can be seen in figure 1, the liner 3 may be easily removed from the outer vessel 2 and may, if desired, e.g. be exchanged for a liner made of a different material.

Figure 2 shows a schematic cross-sectional view of a plurality of parallel reaction vessels 1 as described in Figure 1. On top of the reaction vessels 1 a cover element 7 is placed to simultaneously close the reaction vessels 1. Also further sealing means 8 are provided to prevent undesired fluid leakage between the inside of the outer vessel 2 and the environment via a leak along the flange 6 or other sealing means.

The cover element 7 is provided with a gas inlet 9 connectable to a source of a gas, e.g. to build up a high pressure in the reaction vessel 1.

The person skilled in the art will understand that many modifications may be made. For example, an assembly such as a rack or a reaction block, for housing the reaction vessels 1 may be provided. Also grooves may be provided in the flange 6 and/or the sidewall of the outer vessel 2 as is shown in Fig. 2, for at least partial incorporation of the sealing means 8 and 5. Further, stirring means (magnetic or overhead) such as an orbital shaker, multiple inlets and outlets, and various sensors may be included, if desired, optionally via sealable connections in the cover element 7.

Also, as is mentioned above, the sealing means 5 may, if a gas such as N2 is added via inlet 9, be designed such that they leak above a certain threshold pressure difference between the inside of the liner and the space between the liner and the outer vessel, to equilibrate the pressure on either side of the liner 3. In that case, the liner 3 may be constructed of relatively mechanically weak or brittle materials even if the reaction is performed at a high pressure. In this respect it is noted that it is not the condensable vapour resulting from evaporation of liquid reactant contained in the liner 3 which leaks (as this would possibly result in corrosion of the outer vessel 2) but the gas fed by inlet 9.

The invention allows the use of fragile inner vessels even for high-pressure applications and prevents the contact of corrosive reactant/product vapour from contacting the walls of the pressure resistant outer vessel. A further advantage of the reaction vessel of the invention is that a thermal conducting paste, liquid or solid may be placed between the liner and the outer vessel to improve thermal conduction. The use of the sealing means prevents any vapour produced by the thermal conducting material from contaminating the contents of the inner vessel .

It has been found that good results are obtained when the sealing means between the outer vessel and the liner is designed to resist a pressure of 10 bar.

Note that the gas, which should be allowed to leak between the liner and the outer vessel is not vapour resulting from evaporation of the liquid contained within the liner. The seal between the liner and outer vessel should only leak if a permanent gas (like hydrogen or air) for reaction is added. Hydrogenation reactions, for example, may take place at high pressure (> 100 bar) . It is desirable, therefore, that the hydrogen leaks to the space between the liner and outer vessel until a small pressure difference between the inner vessel and outer vessel is created. This small pressure difference is essentially the vapour pressure of the liquid component, and this is the pressure to be contained by the sealing means. Figure 3 shows a schematic cross-sectional view of a second embodiment of the reaction vessel of the invention. The preferably tubular reaction vessel 1 comprises a pressure resistant outer vessel 2 and a inert liner 3, which liner 3 is contained within the outer vessel 2 and lines the inside of the outer vessel 2. At least the upper portion of the liner 3, e.g. the part lining the flange 6 is, in this embodiment, made from a flexible material, such as Teflon. The outer vessel 2 further comprises a flange 6 in the vicinity of opening 4. The liner 3 is designed such that it also at least partially lines the flange 6. Therefore the liner 3 also functions as sealing means when a closure element, such as a cover, is placed on top of the flange 6.

Again, the liner 3 may be easily removed from the outer vessel 2 and may, if desired, be exchanged for another liner 3 containing a different material to be treated or reacted therein or for an liner made of a different material.

Claims

C L A I M S

1. Reaction vessel (1) for conducting a reaction involving one or more reactants, said reaction vessel comprising: - a pressure resistant outer vessel (2) , said outer vessel having an inner wall; - a liner (3) which is removable contained within the outer vessel (2) and which lines the inner wall of the outer vessel

(2) and thereby avoids contact between the inner wall of the outer vessel (2) and the one or more reactants, wherein a space is present between the outer vessel (2) and the liner (3) , the liner (3) being chemically inert and resistant to the one or more reactants to be contained inside the liner and the liner

(3) having at least one opening (4) in communication with the inside of the liner (3) , characterised in that the reaction vessel (1) further comprises a sealing means (5) arranged near the opening (4) of the liner (3) and sealing the space between the outer vessel (2) and the liner (3) from the inside of the liner (3) at least as the pressure difference across the sealing means (5) is below a threshold pressure difference.

2. Reaction vessel according to claim 1, wherein the threshold pressure difference is such that if a vapour pressure is established by vapour produced by the one or more reactants, said vapour does not enter the space between the liner and the outer vessel.

3. Reaction vessel according to claim 1 or 2, wherein said reaction vessel is provided with a gas inlet connectable to a gas source for introducing a gas into the reaction vessel at a high pressure, and wherein the threshold pressure difference is such that the gas leaks past the sealing means and enters the space between the liner and the outer vessel thereby equilibrating the pressure on either side of the liner.

4. Reaction vessel according to any of claims 1-3, wherein the threshold pressure difference is between 5 and 20 bar, preferably between 5 and 15 bar, in a practical embodiment 10 bar.

5. Reaction vessel according to one or more of the preceding claims, wherein the sealing means (5) are placed between the outer vessel (2) and the inner vessel (3) .

6. Reaction vessel according to claim one or more of claims 1-4, wherein the outer vessel (2) comprises a part, e.g. a flange (6) surrounding an opening for introducing and removing the liner, and wherein the liner (3) has integral sealing means (4) which at least partially line said part of the outer vessel.

7. Reaction vessel according to claim 6, wherein the sealing means are embodied as an annular flange of the liner (3) .

8. Reaction vessel according to one or more of the preceding claims, wherein the sealing means (5) are, at least partially, made from a flexible material.

9. Reaction vessel according to claim 8, wherein the flexible material is a compressible material such as Teflon.

10. Reaction vessel according to one or more of the preceding claims, wherein a thermal conduction enhancing substance is placed in the space between liner and the outer vessel to improve thermal conduction between the liner and the outer vessel .

11. Reaction vessel according to one or more of the preceding claims, wherein the material of the liner is brittle, e.g. glass .

12. Reaction vessel according to one or more of the preceding claims, wherein the liner contains a flexible part forming the sealing means.

13. Reaction vessel according to claim 12, wherein the liner is entirely made from a flexible material.

14. Reaction vessel according to one or more of the preceding claims, wherein the liner is tubular having a closed bottom and a single opening at the top, and the outer vessel is tubular having a closed bottom and an opening at the top for placing and removing the liner, said outer vessel comprising a closure element for closing the opening of the outer vessel.

15. Method for conducting a reaction, wherein use is made of a reaction vessel according to one or more of the preceding claims .

16. Method according to claim 15, wherein said reaction vessel containing the one or more reactants is heated to a reaction temperature, thereby producing vapour having a vapour pressure at said reaction temperature, and wherein the sealing means prevent the vapour from entering the space between the liner and the outer vessel.

17. Method according to claim 15 or 16, wherein a gas, preferably a permanent gas, e.g. hydrogen, is introduced into the reaction vessel containing the one or more reactants, the reaction vessel being heated to the reaction temperature prior to or after the introduction of the gas.

18. Method according to any of claims 15-17, wherein the reaction vessel is cooled down.

19. Apparatus, in particular suitable for high throughput experimentation, comprising at least one reaction vessel (1] according to one or more of the preceding claims.