DEVICE AND METHOD FOR EXAMINING REACTIONS

Abstract

The invention relates to an apparatus for analyzing reactions, comprising at least one reactor (1) and at least two sample vessels (13), wherein, in the case of an apparatus having one reactor (1), the reactor (1) is connected to at least two sample vessels (13), and, in the case of an apparatus having more than one reactor (1), each reactor (1) is connected to at least one sample vessel (13). The invention further relates to a method of analyzing reactions in such an apparatus.

Claims

1. An apparatus for analyzing reactions, comprising multiple reactors (1), wherein each reactor (1) is connected to at least two sample vessels (13), wherein each sample vessel (13) has an adjustable volume.

2. The apparatus according to claim 1, wherein each sample vessel (13) comprises a cylinder with a piston (17) movable therein.

3. The apparatus according to claim 2, wherein sensors (31, 33) by which the position of the movable piston (17) is detected are mounted on the sample vessel (13).

4. The apparatus according to claim 1, wherein each reactor (1) comprises an outlet connected to a multiway valve (51), and each outlet of the multiway valve (49) is connected to a sample vessel.

5. The apparatus according to claim 1, wherein a switchable valve by which the feed into the sample vessel (13) can be controlled is accommodated between the reactor (1) and the sample vessel (13).

6. The apparatus according to claim 1, wherein reaction media can flow continuously through the reactors (1).

7. The apparatus according to claim 1, wherein the sample vessels (13) are heatable.

8. The apparatus according to claim 1, wherein the sample vessels (13) are connected to a source of an inert medium.

9. A method of analyzing reactions in an apparatus according to claim 1, comprising: (a) performing a reaction in each of the reactors (1), where all reactions are conducted under the same reaction conditions or where the reaction conditions are varied in each reactor (1); (b) taking a sample from each reactor (1) at a given time into the sample vessel (13), wherein a sample is taken at the given time from each reactor (1), or pulsed sampling, wherein reaction medium taken from the reactor (1) with each sampling pulse is introduced into a new sample vessel (13); (c) analyzing the samples present in the sample vessels (13).

10. The method according to claim 9, wherein pressure and/or temperature is detected during the reaction in each reactor (1).

11. The method according to claim 9, wherein the sample taken from the reactor (1) is mixed with an inert medium in the sample vessel (13).

12. The method according to claim 9, wherein samples taken successively from the reactor, before being analyzed in step (c), are transferred from the sample vessel (13) to a further vessel, and the mixture of samples taken at various times that is produced in the vessel is analyzed.

13. The method according to claim 9, wherein the analysis of the sample is performed by means of an analytical method from the group of chromatographic, spectrometric and spectroscopic methods or a combination thereof.

14. The method according to claim 9, wherein the mixture of samples taken at different times is used to generate models of chemometric methods.

Description

[0044] The figures show:

[0045] FIG. 1 a section of an apparatus for analysis of reactions, having a reactor and a sample vessel,

[0046] FIG. 2 an apparatus for analysis of reactions, having a separator,

[0047] FIG. 3 an apparatus for analysis of reactions, having one reactor and multiple sample vessels,

[0048] FIG. 4 an apparatus for analysis of reactions, having multiple reactors,

[0049] FIG. 5 an apparatus for analysis of reactions, having multiple reactors, in a further embodiment.

[0050] FIG. 1 shows a section of an apparatus for analysis of reactions, having a reactor and a sample vessel.

[0051] For analysis of a reaction, reactants are supplied to a reactor 1 via a feed 3. These are converted to a reaction product in the reactor, with the possibility of complete or partial conversion of the reactants depending on the reaction. In addition, it is also possible to supply the reactor with an inert medium. The reactants may be supplied to the reactor either individually via respectively separate feeds 3 or alternatively, as shown here, mixed in a mixer 5 and then introduced into the reactor via the feed 3.

[0052] It is possible to use any desired catalyst suitable for the reaction to be analyzed in reactor 1. When a homogeneous catalyst is used, this is preferably mixed into the reactants. Even if further substances that do not take part in the reaction, for example initiators, are required, these are either introduced directly into the reactor or alternatively already mixed with the reactants prior to introduction into the reactor, for example in the mixer 5.

[0053] In the case of a heterogeneously catalyzed reaction, the catalyst is preferably accommodated in the reactor in a fixed manner, for example as a packing or bed. Alternatively, however, it is also possible to use the catalyst in the form of a fluidized bed or moving bed. A moving bed is preferred especially when the catalyst has to be regularly exchanged or regenerated.

[0054] An outflow conduit 7 is used to withdraw the reaction mixture generated in the reactor 1 from the reactor. In order to be able to analyze the reaction mixture, samples of the reaction mixture have to be taken. For this purpose, a sample conduit 9 branches off from the outflow conduit 7. This is connected via a first valve 11 to a sample vessel 13. If the intention is to analyze the entire reaction mixture generated in the reactor, it is unnecessary to provide a sample conduit 9 branching off from the outflow conduit 7. In this case, the outflow conduit 7 may be connected directly to the sample vessel 13, in which case the first valve 11 upstream of the feed into the sample vessel 13 is also required in order to be able to stop the flow of the reaction mixture into the sample vessel 13.

[0055] In order to take a sample, the first valve 11 is opened. With the first valve 11 open, it is then possible for reaction mixture to flow out of the reactor 3 via the sample conduit 9 into a sample chamber 15 in the sample vessel 13. The sample chamber 15 is preferably bounded, as shown here, on one side by a piston 17 movable within the sample vessel 13. The piston 17 can be used to adjust the volume of the sample chamber 15 in the sample vessel 13. At the start of the sampling, the piston 17 is preferably in a first position in which the volume of the sample chamber 15 is at a minimum. With commencement of sampling, the piston 17 then moves in the direction of a second position in which the volume of the sample chamber 15 is at a maximum. As soon as the piston 17 has reached the second position or if the sampling is to be ended before the piston has reached the second position 17, the valve 11 is closed, such that no further reaction mixture can flow into the sample chamber 15 in the sample vessel 17.

[0056] The movement of the piston 17 can be assisted for sampling in that a pressure lower than the pressure of the reaction mixture is applied to the side of the piston 17 remote from the sample chamber 15. This simultaneously leads to suction of reaction mixture into the sample chamber 15. In order to apply the lower pressure to the side of the piston 17 remote from the sample chamber 15, it is possible, for example, for a gas conduit 19 on the side of the piston 17 remote from the sample chamber 15 to open into the sample vessel 13. In order to apply the lower pressure, the gas conduit 19 sucks gas out of the sample vessel, such that the piston 17 moves in the direction of its second position. As soon as the sampling is to be ended, the suction of the gas is ended.

[0057] The reaction mixture present in the sample chamber 15 is then sent to an analysis unit 21 in a next step. It is possible here to use any desired analysis unit with which the desired analyses on the gas mixture can be conducted. Customary analysis units are especially those with which the composition of the reaction mixture can be determined. In order to be able to supply the reaction mixture to the analysis unit 21, the analysis unit 21 is connected via a measurement conduit 23 to the sample chamber 15 in the sample vessel 13. In order to be able to close the measurement conduit 23, a second valve 25 is accommodated in the measurement conduit 23. During the sampling, the second valve 25 is closed.

[0058] In order to supply the sample to the analysis unit 21, the second valve 25 is opened. Then the piston 17 is moved in the direction of its first position, such that the reaction mixture present in the sample chamber 15 is forced out of the sample chamber 15 into the measurement conduit 23 by the movement of the piston 17 and supplied to the analysis unit 21 through the measurement conduit 23. The piston 17 can be moved either with a suitable drive or, as shown here, with the aid of pressurized gas which flows into the sample vessel via the gas conduit 19 and thus acts on the side of the piston 17 remote from the sample chamber 15. The pressure exerted on the piston 17 by the pressurized gas forces it in the direction of the sample chamber, such that the reaction mixture present in the sample chamber is forced into the measurement conduit 23. As soon as the piston 17 has reached its first position at which the volume of the sample chamber is at a minimum, the supply of pressurized gas is ended. For this purpose, a third valve 27 is preferably provided in the gas conduit 19. The supply of pressurized gas is ended by closing the third valve 27.

[0059] After the sample chamber 15 has been emptied completely, another sample can then be taken.

[0060] Especially in the case of a hot reaction mixture, it is advantageous when the sample vessel is heatable. For this purpose, preference is given to using an electrical heater 29. The electrical heating can be implemented, for example, by means of heating coils surrounding the sample vessel 13. Alternatively, it is also possible to use a heating jacket.

[0061] For control of the movement of the piston 17, position sensors are preferably provided. A first position sensor 31 detects whether the piston 17 is in the first position, and a second position sensor 33 whether the piston 17 is in the second position. The position sensors 31, 33 are especially utilized in order to control the movement of the piston by application of reduced pressure or elevated pressure. If a sample is taken, the removal of gas to generate a pressure below the pressure of the reaction mixture is ended when the second position sensor 33 detects that the piston 17 has reached its second position. Accordingly, the pressurized gas supply in the removal of the sample from the sample chamber 15 is ended when the first position sensor 31 detects that the piston 17 has reached its first position.

[0062] As an alternative to the above-described embodiment with pneumatic movement of the piston 17, it is also possible for the piston to be moved hydraulically. In this case, rather than a gas, a fluid is used, which is sucked out of the sample vessel 13 when the piston 17 is to move into the second position, and forced into the sample vessel 13 in order to move the piston 17 into its first position.

[0063] As well as the pneumatically or hydraulically assisted movement of the piston, movement of the piston is alternatively also possible with the aid of a drive, for example with a step motor. When a step motor is used, it is directly also possible to detect the position of the piston, such that the position sensors 31, 33 can be dispensed with in this case. When a drive that does not permit determination of the piston position is used for the piston, however, the use of the position sensors 31, 33 is advantageous in order to end the movement of the piston in the respective direction by stopping the drive as soon as the corresponding position sensor 31, 33 has detected the piston.

[0064] FIG. 2 shows an alternative embodiment of a section from an apparatus for analysis of reactions, comprising a reactor and a sample vessel connected to the reactor. By contrast with the embodiment shown in FIG. 1, the reactor 1 here has been provided with a separator 35. In the separator 35, it is possible to separate out liquid formed in the reaction. This is necessary especially when the analysis unit 21 must not be supplied with any gas. For this purpose, the outflow conduit 7 from the reactor opens into the separator 35, such that the reaction mixture from the reactor 1 is supplied to the separator 35 through the outflow conduit 7. Liquid is then separated out of the reaction mixture in the separator and withdrawn via a withdrawal conduit 37. The withdrawal conduit 37 can be closed by a fourth valve 39, such that the separator 35 can in each case be emptied at desired or defined times. This is possible, for example, at defined time intervals or on attainment of a defined liquid level. In addition, it is also possible to supply the liquid separated out in the separator 35 to an analysis unit in order to quantitatively and/or qualitatively analyze the liquid separated out, especially to determine the components present in the liquid and optionally also the quantity of the individual components present in the liquid.

[0065] In addition, it is possible to conduct an inert gas conduit 41 into the separator. By means of the inert gas conduit, it is possible to dilute the reaction mixture. This may be necessary, for example, when the concentration of individual components would otherwise be too high for the analysis. Alternatively, it is also possible to use the gas supplied via the inert gas conduit 41 to drive out gas still present in the liquid that collects in the separator. This is necessary, for example, for quantitative analysis of the reaction mixture. In order still to be able to drive gas out of the liquid, the inert gas conduit 41 preferably opens into the liquid collected in the separator 35 as an immersed tube. In order to ensure this, liquid is preferably removed in that case only to such a degree as to attain a minimum liquid level that is still sufficiently high for the inert gas conduit 41 to be immersed in the liquid. Suitable inert gases that are supplied via the inert gas conduit 41 are, for example, nitrogen or noble gases, preferably nitrogen.

[0066] At a position above the maximum liquid level, the sample conduit 9 branches off from the separator 35, through which gaseous reaction mixture can be introduced into the sample vessel 13. Sampling is effected in the same way as described above for FIG. 1.

[0067] In order to facilitate sampling from the separator 35, a vacuum pump 43 is provided. The vacuum pump 43 can be used to apply a pressure lower than the pressure in the separator to the side of the piston 17 differing from the sample chamber 15. As a result, with the first valve 11 open, gaseous reaction mixture is sucked out of the separator 35 into the sample chamber 15. The vacuum pump 43 is especially advantageous when the reaction is performed under ambient pressure or a pressure below ambient pressure. When the reaction is performed at a pressure above ambient pressure, in general, one outlet to the environment is sufficient, since, in this case, the positive pressure of the reaction mixture forces the reaction mixture into the sample chamber 15 and moves the piston 17 upward. In order to prevent the piston from being forced upward too quickly, it is possible in this case either to provide the piston with a weight or preferably to insert a valve in the outlet to the environment that can be opened only to such an extent that the piston is raised at the desired speed. A construction as shown in FIG. 1 is sufficient for this purpose.

[0068] Alternatively, it is also possible to dispense with the pump 43 and to generate the positive pressure needed in the separator 35 by the supply of the inert gas through the inert gas conduit 41. In order that the reaction mixture can be withdrawn from the sample chamber 15, as described above, a positive pressure is then applied to the opposite side of the piston 17 from the sample chamber 15, such that the piston 17 is forced in the direction of the sample chamber 15 and hence the mixture present in the sample chamber 15 is guided out of the sample chamber 15 through the measurement conduit 23 to the analysis unit 21.

[0069] For control of the piston 17, in the embodiment shown in FIG. 2, a controllable valve 45 is accommodated in the gas conduit 19. For this purpose, the pressure is measured in the gas conduit 19 between the sample vessel 13 and the controllable valve 45, and the valve is controlled with a pressure regulator 47. When the pressure measured in the gas conduit 19 differs from the desired pressure, the controllable valve 45 is set correspondingly. The controllable valve 45 is opened further if too low a pressure is measured, and closed further if too high a pressure is measured. If too low a pressure is measured, during the sampling, the piston 17 is moved too quickly into its second position and the volume of the sample chamber 15 is increased; when the piston 17 is moved into its first position, the piston 17 is moved too slowly and the reaction mixture present in the sample chamber 15 is guided too slowly from the sample chamber 15 into the analysis unit 21. If too high a pressure is measured, during the sampling, the piston 17 is moved too slowly, such that the sampling is not fast enough, or the pressure that acts on the piston 17 is even so high that it does not move and hence no sample is taken. When the piston 17 is moved into its first position, the effect of an excessively high pressure is excessively rapid movement in the first position, such that the reaction mixture is displaced too quickly from the sample chamber 15.

[0070] In order to analyze the progression of the reaction over a longer period, multiple sample vessels are connected to the reactor, which can each successively accommodate a sample. This is shown by way of example for a reactor in FIG. 3.

[0071] In order to be able to successively take multiple samples from the reactor, the reactor is connected via a multiway valve 49 to multiple sample vessels 13. There is additionally a 3-way valve 51 between the reactor and the multiway valve 49. The 3-way valve 51 is utilized either to establish a connection from the reactor 1 to the sample vessels 13 or alternatively from the sample vessels 13 to the analysis unit 21. In order to be able to take a sample, the 3-way valve 51 is adjusted such that a connection from the reactor 1 to the multiway valve 49 is open, and the connection from the multiway valve 49 to the analysis unit 21 is closed. The multiway valve 49 is then used to open the connection to the respective sample vessel 13 that is to be filled during the sampling. Accordingly, for the analysis of the samples present in the sample vessels 13, the 3-way valve 51 is connected such that the connection from the 3-way valve 51 to the analysis unit 21 is open and, by the multiway valve 49, the connection to the sample vessel 13 from which the desired sample is to be taken and guided to the analysis unit 21.

[0072] With the multiway valve 49, it is possible in a simple manner to successively take multiple samples by, after sampling into a sample vessel 13 has ended, switching over the multiway valve 49 and opening the connection to the next sample vessel 13. This can be repeated until samples are present in all sample vessels 13. Accordingly, it is then also possible to supply the samples from the individual sample vessels 13 successively to the analysis unit 21 by, in the course of sampling too, switching over the multiway valve 49 to a further sample vessel 13 as soon as a sample vessel 13 has been emptied. In order to assist the movement of the pistons 17 in the sample vessels, each sample vessel 13 is connected to a gas conduit 19 here too, such that—as described above for FIGS. 1 and 2—the movement of the piston 17 can be assisted by application of pressure on the side remote from the sample chamber 15 or by application of a reduced pressure on the side remote from the sample chamber 15. In this case, it is possible to simultaneously exert the pressure on all pistons or simultaneously to apply reduced pressure to all pistons 17, since only in the sample vessel 13 to which the connection through the multiway valve 49 is open is it possible to move the piston 17 for accommodation of a sample or for emptying. In the other sample vessels, owing to the closed connection, a pressure equilibrium is established, which prevents the movement of the piston.

[0073] Here too, the third valve 27 is accommodated in the gas conduit 19 through which the gas is guided to assist the piston movement. The valve may be equipped with a pressure gauge 52 in order thus to have control over whether a sample vessel 13 is currently being filled or emptied. In the case of a pressure below the reactor pressure, a sample vessel 13 is being filled, and, in the case of a pressure above the reactor pressure, the sample from a sample vessel 13 is being supplied to the analysis unit 21.

[0074] FIG. 4 shows a further embodiment of an apparatus for analysis of reactions.

[0075] The embodiment shown in FIG. 4 differs from that shown in FIG. 3 by the connection of multiple reactors 1 to the sample vessels 13. In order to connect the reactors 1 to the sample vessels, a second multiway valve 53 is included, via which the reactors 1 are connected to the 3-way valve 51. In the embodiment shown here, a sample can be taken from one reactor 1 in each case. For this purpose, the second multiway valve 53 is connected such that a connection from the reactor 1 from which the sample is to be taken to the 3-way valve 51 is open. The connection from the other reactors 1 to the 3-way valve 51 is closed. By virtue of the multiway valve 49, it is then possible to take multiple samples successively. Alternatively, it is also possible to take just one sample from each reactor. In this case, after the taking of a sample, both multiway valves 49, 53 are switched in order to open the connection from a further reactor 1 to a further sample vessel 13. This can be repeated until samples have been taken from all reactors and all sample chambers 15 comprise a sample.

[0076] After the sampling, the samples can be supplied to the analysis unit 21. This is effected as described above for FIG. 3. By the construction shown here, it is only possible to take one sample or to guide one sample from a sample vessel 13 to the analysis unit 21. It is not possible simultaneously to take a sample from a reactor and to supply a sample already taken from another sample vessel 13 to the analysis unit 21.

[0077] In order to perform the same reaction in multiple reactors, it is advantageous to connect all reactors that are to be supplied with the same reactant composition to a common mixer 55. Reactors that are to be supplied with a different reactant composition are connected to a different mixer 5. If a different composition is to be examined in each reactor, it is necessary to connect each reactor 1 to a separate mixer 5.

[0078] Alternatively, in all embodiments, it is of course also possible to introduce the reactants directly into the reactors 1 and to dispense with the upstream mixers 5, 55. It is also possible for the mixing to be effected in the feed 3 in that the individual reactants are introduced into the feed 3 via a suitable connection site.

[0079] In addition, it is possible to configure the apparatus such that multiple reactors are provided, each connected to multiple sample vessels. In this case, the second multiway valve 53 is not required since each reactor has its own group of sample vessels.

[0080] FIG. 5 shows an apparatus for analysis of reactions in a further embodiment. By contrast with FIG. 4, in the embodiment shown in FIG. 5, the reactors 1 are each connected to a separator 35. The construction of reactor and separator corresponds to that shown in FIG. 2. The sampling is effected as described above for FIG. 4.

[0081] Unlike the embodiments described above for FIGS. 1 to 4, the analysis region comprises multiple analysis units 21. For this purpose, multiple 3-way valves 59, 63 are accommodated in the measurement conduit 23. It is possible either for each 3-way valve 59, 63 to be used to open a connection to an analysis unit 61, 65 or for a connection to be opened to a downstream 3-way valve or an outlet 57. For example, it is possible first to switch the first 3-way valve 59 such that reaction mixture is supplied to the first analysis unit 61. Subsequently, the first 3-way valve 59 is switched such that the reaction mixture is guided past the first analysis unit 61 to the second 3-way valve 63. The second 3-way valve 63 is then switched such that the reaction mixture is guided into the second analysis unit 65. If no sample is to be taken, both 3-way valves 59, 63 are switched such that the reaction mixture goes to the outlet 57. It is also possible here to guide a sample only to one analysis unit 61, 65 in each case, the analysis unit 61, 65 utilized being dependent on the analysis to be conducted. In addition, it is also possible, especially in the case of longer-lasting analyses, to supply a sample to the first analysis unit 61 and, while the sample is still being analyzed, a further sample from another sample vessel to the second analysis unit 65. If the analyses take a very long time, it is also possible for acceleration of the analyses to use further analysis units that can each be operated in parallel.

LIST OF REFERENCE NUMERALS

[0082] 1 reactor

[0083] 3 feed

[0084] 5 mixer

[0085] 7 outflow conduit

[0086] 9 sample conduit

[0087] 11 first valve

[0088] 13 sample vessel

[0089] 15 sample chamber

[0090] 17 piston

[0091] 19 gas conduit

[0092] 21 analysis unit

[0093] 23 measurement conduit

[0094] 25 second valve

[0095] 27 third valve

[0096] 29 heater

[0097] 31 first position sensor

[0098] 33 second position sensor

[0099] 35 separator

[0100] 37 withdrawal conduit

[0101] 39 fourth valve

[0102] 41 inert gas conduit

[0103] 43 pump

[0104] 45 controllable valve

[0105] 47 pressure regulator

[0106] 49 multiway valve

[0107] 51 3-way valve

[0108] 52 pressure gauge

[0109] 53 second multiway valve

[0110] 55 common mixer

[0111] 57 outlet