EP3856403A1

EP3856403A1 - Apparatus and method for analyzing reactions

Info

Publication number: EP3856403A1
Application number: EP19773079.9A
Authority: EP
Inventors: Armin Lange De Oliveira
Original assignee: HTE GmbH the High Throughput Experimentation Co
Current assignee: HTE GmbH the High Throughput Experimentation Co
Priority date: 2018-09-24
Filing date: 2019-09-23
Publication date: 2021-08-04
Also published as: US20220040661A1; US11752484B2; WO2020064624A1

Abstract

The invention relates to an apparatus for analyzing reactions, comprising a reactant distributor (7) and at least two reactors (3) which are connected in parallel and which are each connected, via a connection line (5), to an outlet of the reactant distributor (7). In order to set the inflow, each connection line (5) contains, between the reactant distributor (7) and the reactors (3), a pressure regulator (33) and a restrictor (19), or branching off from each connection line (5) there is an outlet line (13) which contains a restrictor (19) and a pressure regulator (33). The invention also relates to a method for analyzing reactions in such an apparatus.

Description

Device and method for analyzing reactions

description

The invention is based on a device for analyzing reactions, comprising an educt distributor and at least two reactors connected in parallel, each of which is connected to an outlet of the educt distributor via a connecting line. The invention further relates to a method for analyzing reactions in such a device.

Devices for analyzing reactions with at least two reactors connected in parallel can be used, for example, to examine reaction parameters such as pressure or temperature. However, such a device is particularly suitable for testing catalysts, the same educt volume flow being fed to each reactor of the device in order to obtain comparable reaction conditions and thus to be able to investigate the influence of the catalyst on the reaction.

Such a device with fixed bed reactors arranged in parallel with a device which largely uniformly distributes the feed streams to the reactors is described, for example, in WO-A 99/64160. In order to obtain an even distribution of the input streams across the reactors, restrictors are used to increase the flow resistance. Capillaries, microchannels and diaphragms in one channel are mentioned as restrictors, for example. For example, WO-A 2015/080572 discloses the use of microchannels in the feed to the individual reactors.

A disadvantage of the restrictors known from WO-A 99/64160 and WO-A 2015/080572 is that they do not allow variable adjustment of the flow resistance and therefore no individual adjustment of the feed streams to the reactors arranged in parallel is possible. In order to vary the volume flow of the educt streams, it is necessary to replace the restrictors. Furthermore, an exact setting of the feed streams is not possible because small differences in the geometry of the restrictors, which cannot be prevented due to the manufacturing process, lead to small deviations in the volume flows.

In order to be able to adjust the educt streams, a liquid distributor with capillaries as restrictors for the distribution of educt streams to the reactors is known from WO-A 2009/145614, in which the capillaries can be heated so that the flow resistance can be varied. However, these thermally adjustable restrictors have the disadvantage that they have to be calibrated regularly and are very complex in terms of circuitry. In addition, the heatable capillaries also have restrictions with regard to possible process parameters, in particular the temperature and the adjustable range of the volume flow as a function of the process pressure, so that here too, if necessary, an exchange for other re capillaries may be necessary if the desired volume flow cannot be set with the existing capillary.

If an individual flow control is designed by tempering a capillary, the temperature dependence of the viscosity must be known. In particular for complex hydrocarbon mixtures such as vacuum gas oil, the temperature dependence of the viscosity can be determined experimentally. Alternatively, there is only the option of determining the flow and empirically adapting the temperature of the capillary, which, however, requires a great deal of regulation and measurement. Furthermore, the measurement of small flows at high temperatures (> 180 ° C) is only possible or not possible to a limited extent. Another disadvantage is that changing or adapting the temperature-controlled capillary is complex, since it has to be brought into good thermal contact with the individual heating system.

The effects of varying the temperature of a capillary are usually minor because the viscosity of ideal gases, for example, only changes according to the root of the absolute temperature. The viscosity of ideal liquids changes exponentially with the inverse absolute temperature (Arrhenius-Andrade relationship), so that depending on the liquid and temperature, the flow change can be very small to very large.

Furthermore, the temperature cannot be set arbitrarily because, for example, the melting point, boiling point or decomposition point of a medium must be taken into account. The operation of a capillary at a higher temperature can also lead to the accelerated formation of deposits in the capillary, which increase the flow resistance of the capillary, so that a further temperature increase is necessary. This creates feedback that can lead to premature system failure.

From WO-A 2014/062056 it is known to use a pressure regulator for setting the pressure in the individual reactors at the outlet of each reactor, which uses an auxiliary fluid, the reference pressure of which is used to set the flow cross-section for the reaction medium flowing through the pressure regulator. The pressure of the auxiliary fluid is set by using two restrictors, at least one of which can be temperature-controlled. The pressure in the reactor can be set using the pressure regulator connected to the reactor. If the reactor pressure is changed, the flow rate is also changed when restrictors are used in the feed. The disadvantage is that the reactor pressure and flow are not controlled independently of each other.

It is therefore an object of the present invention to provide a device for analyzing reactions in which an individual adjustment of the pressure difference with the required precision is possible for each restrictor upstream of the reactors under operating conditions which does not require any permanent calibration effort and in particular also for high ones Temperatures is suitable. The object is achieved by a device for analyzing reactions, comprising a starting material distributor and at least two reactors connected in parallel, each of which is connected to an outlet of the starting material distributor via a connecting line, with the setting of the inflow in each connecting line between the starting material distributor and the Reactors a pressure regulator and a restrictor are included or that an outlet line branches off from each connecting line, in which a restrictor and a pressure regulator are accommodated.

The combination of restrictor and pressure regulator enables an improved fine tuning of the fluid flows into the individual reactors. In particular, the fluid flow flowing through the restrictor can be regulated without the fluid flow being adjusted without permanent calibration, as in the regulation known from the prior art by adjusting the temperature of the capillaries. Also, particularly when using pressure regulators with high accuracy and short settling times, rapid changes in the educt flow through the pressure regulator and restrictor are possible. In addition, when regulating by setting the temperature, the melting point, boiling point or decomposition point of a medium must be taken into account, whereas in the case of individual flow control on the basis of the upstream and downstream pressure, these aspects need not be taken into account, so that the control system has a larger working range.

The alternative embodiment with an outlet line in the connecting line, with a restrictor and a pressure regulator being accommodated in the outlet line, allows the flow into the reactor to be adjusted by removing part of the feed stream supplied. This has the advantage that no further pressure increase is effected on the feed side into the reactor and, furthermore, if the pressure difference between the reactor and the outlet channel is large, the educt flow can be set with greater accuracy.

Suitable pressure regulators are, for example, diaphragm pressure regulators, piston pressure regulators, bellows pressure regulators or proportional pressure relief valves. These can be spring-loaded, cathedral-loaded or both. Furthermore, the pressure regulators can be single-stage or multi-stage. Depending on the position of the pressure regulator, primary pressure regulators or secondary pressure regulators are used, whereby electronically controlled pressure regulators can also be used. However, it is preferred to use spring-loaded diaphragm or piston pressure regulators, which can be used directly acting or which serve to control the diaphragm pressure reducers, since they do not require any further control device of their own. Dome-loaded pressure reducers in particular have the advantage that they can also be operated at very high temperatures, that is to say temperatures up to 300 ° C and even up to 700 ° C for lower pressures, and thus the pressure control of vapors from high-boiling products Enable substances. The dome pressure can be finely controlled outside the heated area, while the actual diaphragm pressure regulator in the hot area is supplied with the dome pressure by means of a pipe connection. Dome-loaded membrane upstream pressure regulators, as described, for example, in WO-A 2012/178132, are particularly suitable for small flow rates. The device is suitable both for reactions to which liquid educt streams are fed and for those to which gaseous educt streams are fed. In addition to the addition of liquid feed streams or gaseous feed streams, it is also possible to supply liquid and gaseous feed streams, the gaseous feed streams and the liquid feed streams each being fed to the reactor via separate feed lines. In this case, it is also possible to bring the feed lines together in a connection point and to feed the starting material mixture of liquid and gaseous starting material formed in the connection point to the reactor. In this case, if there are more than two starting materials, at least one starting material can be gaseous and all other starting materials can be liquid or at least one starting material can be liquid and all other starting materials can be gaseous . The device for analyzing reactions in the gas phase, to which the starting materials are supplied in gaseous form, is particularly suitable.

In one embodiment of the invention, the pressure regulator is accommodated between the educt distributor and the restrictor. In this embodiment, the pressure regulator is a holding pressure regulator in order to adjust the pressure difference across the restrictor and thus the volume flow of the educt flow through the restrictor.

Alternatively, it is also possible for the pressure regulator to be accommodated between the restrictor and the reactor. In this embodiment, the pressure regulator is a pre-pressure regulator in order to adjust the pressure difference across the restrictor and thus the volume flow of the educt flow through the restrictor.

If a drain line with a pressure regulator and restrictor is provided, a pre-pressure regulator is also used if the pressure regulator is arranged downstream of the restrictor and a hold pressure regulator if the pressure regulator is positioned upstream of the restrictor.

In particular, if particularly small educt flows are desired, as is desirable in the parallel test, it is preferred to arrange the pressure regulator in the flow direction behind the restrictor and to use a pre-pressure regulator.

The pressure difference that is present at the restrictor is controlled with the pressure regulator. This pressure difference determines the educt flow for a given flow resistance in the restrictor. In this way, the educt flow fed to the reactor can be set precisely with the aid of the pressure regulator, and deviations in the educt flow which cause a change in the pressure difference in the restrictor can be quickly corrected. The pressure drop across the restrictor usually results from the reactor pressure and the pressure in the supply line. The pressure in the supply line arises from the pressure drop across all restrictors that is generated when the total volume flow flows through and is therefore dependent on Total volume flow, the viscosity of the flowing medium and the geometry of the remaining restrictors. With a given flow resistance, which depends on the medium used and the geometry of the restrictor, the pressure regulator adjusts the pressure difference along a restrictor and thus regulates the volume flow through the restrictor. Flow resistance here means the variable that describes the ratio of pressure difference to volume flow for non-compressible fluids and is constant for laminar flow. In the case of compressible fluids, it refers to the ratio of a difference of the squares of inlet pressure and outlet pressure to volume flow standardized to normal pressure and is also a constant for a laminar flow, which in the case of pipe flow, for example, is determined by the inside diameter and length of the pipe and by the Viscosity of the medium is determined. Alternatively, it is also possible to set the pressure in the educt distributor, for example by using a pressure relief valve or a pressure regulator and thus to maintain a constant pressure on the inlet side in the restrictor, so that at a given pressure in the feed before and after the restrictor the flow in the reactor can be adjusted. The pressure in the reactor is preferably controlled by a pressure regulator which is positioned behind the reactor in the direction of flow. This can also be connected to the analysis unit, for example.

All restrictors known to those skilled in the art can be used as restrictors. Here, restrictors are components that have a high flow resistance and thus generate a high pressure loss. In order to obtain a uniform distribution of the fluid flow over the reactors connected in parallel, it is necessary that the pressure loss generated in the restrictor is greater than the pressure loss across the other parts of the plant. Suitable restrictors are in particular capillaries, microstructured components, orifices or nozzles. Capillaries are particularly preferably used as restrictors. This has the advantage that the educt flow through the restrictor designed as a capillary can be easily determined using the Hagen-Poiseuille law for laminar pipe flow. As an alternative to this, it is also possible to check and adjust the feed stream by analyzing the reaction mixture leaving the reactor in the analysis unit.

In order to be able to supply the reactors with a second feed stream or an inert stream for diluting the reaction media, it is advantageous if the reactors are connected to a further distributor. It is also possible, when the reactors are connected to an educt distributor and a further distributor, to feed an educt via each distributor, which are then mixed in the reactor and brought to reaction. If more than two material streams are to be fed to the reactor, it is also possible to provide more than two distributors which are connected to the reactors, with each distributor being supplied with a different material stream which is then distributed to the reactors via the distributor . A restrictor is positioned between the further distributor or the further distributors and each reactor in order to adjust the material flow which is fed to the reactors via the distributors. In each case there is a restrictor between the further distributor and the reactors connected to the further distributor In particular, it is sufficient if the material flow fed to the reactors via the further distributor does not have to be set and even slight fluctuations have no discernible influence on the reaction. This is particularly the case if a stream of material is fed via the further distributor which is very much larger than the stream of material supplied via the educt distributor or if an inert gas stream is fed via the further distributor if the dilution caused by the inert gas stream Educts supplied via the educt distributor has no influence on the reaction.

If a precise adjustment of the material flow supplied via the further distributor or distributors is required, for example when a further starting material is supplied via the further distributor or distributors, it is advantageous to also between the further distributor and each restrictor or between each additional distributor downstream restrictor and the subsequent reactor to accommodate a pressure regulator. The same pressure regulators can be used as pressure regulators as are also used in the connecting lines between the educt distributor and the reactors.

In addition to the dosing of starting materials and inert streams, the dosing of moderators for catalytic reactions is also important. The moderators are not inert, but do not react in the actual target reaction, but rather in a reversible manner with the catalyst, for example by adsorbing onto the active component of the catalyst like CO or reacting like ethyl chloride with the active component and reversibly forming a chloride. Properties of the catalyst are changed, the metering amounts of moderators having to be adapted to the catalyst in order to optimally carry out the target reaction. For this, very precise dosing quantities must be observed and these must be variably adjustable for each catalyst. In such cases, it is preferred to be able to adjust the material flow of gas containing moderator precisely and variably.

If several starting materials or at least one starting material and at least one inert stream are fed via several distributors and feed lines, it is also possible to combine the individual feed lines in front of the reactor to form a common feed line in the reactor, so that the individual material flows are introduced into the reactor via the common feed line will. In this case, the pressure regulator can also be positioned in the common supply line after the material flows have been brought together. If an outlet line is additionally provided before it is fed into the reactor, it can branch off from the common feed line either in the direction of flow of the material flows upstream of the pressure regulator or in the direction of flow of the material flows behind the pressure regulator. It is preferred if the outlet line branches off from the common supply line behind the pressure regulator. This enables improved control of the flows or the respective pressures because the pressure regulators are connected in series and not in parallel. If a pressure regulator is accommodated in the common feed line, restrictors for the educt streams and / or inert streams are preferably accommodated in all feed lines. In this embodiment, since the pressure regulator is positioned between the restrictors and the reactor, the pressure regulator is preferably a pre-pressure regulator.

A large number of reactors is required, in particular in order to carry out serial examinations, for example for testing catalysts. For this purpose, it is preferred if the device comprises 2 to 80 reactors. It is further preferred if the device comprises 4 to 50 reactors and in particular 4 to 20 reactors. The maximum number of reactors depends, among other things, on the volume of the individual reactors, the size of the components and the available space. In addition, it is necessary that the length of the pipelines connecting the reactors to the educt distributor and possibly further distributors does not differ too much in order to prevent fluctuations in the material flows to the individual due to the different pressure losses due to different lengths of the pipelines Reactors occur. If the material flows are measured with a suitable flow measuring device immediately before entering the reactors or on the basis of inert flows after the reactors, for example in the analysis unit, this pressure loss can, however, be adjusted by adjusting the pressure regulator in the connecting line between the reactant distributor or further Distributor and reactor compensated and the desired flow rate can be set.

If more reactions have to be carried out for an examination than is possible with one device at the same time, it is possible to either operate several devices in parallel or to carry out the tests in succession in the same device. In order to be able to carry out different reactions or to test different catalysts, it is particularly advantageous if the reactors can be replaced. This allows the reactors to be simply filled with a different catalyst or the use of a different reactor, for example with a different geometry or also a different type of reactor.

Reactors that can be used with the device according to the invention are, in particular, continuously operated reactors, in particular tubular reactors. In addition to tubular reactors, other types of reactors can also be used, for example back-mixed reaction vessels such as stirred tank reactors, jet circulation reactors or cascades, as well as combinations of optionally different or identical reactors, optionally with circulation.

The internal volume of the reactors is preferably 0.1 to 500 ml, more preferably 0.5 to 100 ml and in particular 1 to 50 ml. Like the number of reactors, the size of the reactors also depends, among other things, on the available space. Another parameter for the choice of the size of the reactors are the starting materials to be used or the properties of the reactions to be carried out, such as the reaction rate and thus the necessary residence time in the reactor. In the case of slow reactions that result in a require a long residence time, this can be set, for example, by the length and diameter of a continuously operated tubular reactor.

For the investigation of catalysts or catalytically activated reactions, the catalyst is introduced into the reactor, for example in the form of a bed, suspension, solution or packing. Alternatively, the catalyst can also be designed as a monolith with flow channels accommodated therein. If a catalyst is present in the reactor, it preferably takes up a volume in the form of the bed, suspension, solution, packing or monolith, which is 0.1% to 100% of the reactor volume. Regardless of whether the catalyst is in the form of a bed, a packing or a monolith, the catalytically active material can be introduced directly into the reactor or be supported. Any material known to the person skilled in the art which is used for supported catalysts is suitable as the support material. Suitable carrier materials are, for example, metal oxides, zeolites, ceramics or carbon and mixtures thereof.

In order to be able to investigate the reactions which are carried out in the individual reactors of the device, each reactor is preferably connected to an analysis unit. Alternatively, it is also possible to collect the reaction mixture generated in the reactor in a storage container and to analyze it at a later point in time. The connection of each reactor with an analysis unit has the advantage, however, that time-dependent examinations of the course of the reaction can also be carried out.

Analysis units that can be used are, on the one hand, those with which physical data, for example pressure or temperature, can be recorded, and those with which the components in the reaction mixture can be recorded qualitatively and / or quantitatively. Suitable analysis units are, for example, those that work with chromatographic methods, for example a gas chromatograph or a high-performance liquid chromatograph (HPLC), or those that work according to spectroscopic methods, such as an infrared spectrometer. It is also possible to use different analysis units.

The device is particularly suitable for the investigation of reactions in the gas phase. In such a method for analyzing reactions in a device for analyzing reactions, gaseous starting materials are supplied to each reactor via the starting material distributor, the flow rate of the starting materials being regulated via the pressure regulators and the reaction product from each reactor being evaluated in the analysis unit.

Depending on the parameters to be examined, the device allows the reactors to be loaded with different volume flows of starting material and / or with different partial pressures of the starting materials. This makes it possible to investigate the influence of different parameters such as the composition of the reaction mixture, amount of moderator or residence time on the reaction. In particular, if different catalysts are to be tested, it is necessary that the same conditions prevail in all reactors in order to recognize the influence of the different catalysts on the reaction. For this it is necessary that the reactors are all loaded with the same volume flow, the same composition and with the same pressure. For such an investigation of catalysts, each reactor is filled with a catalyst. It is possible to fill several reactors with the same catalyst to detect deviations in the test conditions or fluctuations in the course of the reaction. Alternatively, however, each reactor can also be filled with a different catalyst.

The educts can be fed in together via the educt distributor. In this case, the educts are mixed upstream of the educt distributor and then fed to the individual reactors via the educt distributor. This is possible in particular if the starting materials only react with one another in the presence of a catalytic converter or only when energy is supplied, for example by increasing the temperature. If the starting materials immediately react with one another on contact, it is advantageous to supply one starting material via the starting material distributor and at least one further starting material via the further distributor. Alternatively, it is also possible to supply dilution gases via the further distributor, for example in order to vary partial pressures. If the starting materials are supplied via different distributors, the diluent gas can then be supplied via a separate distributor or together with a starting material. If all starting materials are supplied via the starting material distributor, the diluent gas is preferably supplied via the further distributor.

Embodiments of the invention are shown in the figures and are explained in more detail in the following description. Show it:

FIG. 1 shows a schematic representation of a device for analyzing reactions,

FIG. 2 shows a reactor of a device for analyzing reactions with a holding pressure regulator for adjusting the flow,

FIG. 3 shows a reactor of a device for analyzing reactions with a pre-pressure regulator for adjusting the flow,

FIG. 4 shows a reactor of a device for analyzing reactions with two educt feeds,

FIG. 5 shows a reactor of a device for analyzing reactions with a pressure regulator in the outlet line, FIG. 6 shows a reactor of a device for analyzing reactions with two educt feeds in a further embodiment,

FIG. 7 shows a reactor of a device for analyzing reactions with two educt feeds in a further embodiment.

Figure 1 shows a schematic representation of a device for analyzing reactions.

A device for analyzing reactions 1 comprises at least two reactors 3, which are connected in parallel and are each connected to an educt distributor 7 via a connecting line 5. If it is not possible to mix the starting materials to be fed to the reactor or if a variable starting material composition is to be obtained, a further distributor 9 is provided, as shown here, via which further starting materials can be supplied. For this purpose, the further distributor 9 is connected to the reactor 3 via a further connecting line 11. The further connecting line 11 can, as shown here, open into the connecting line 5, with which the educt distributor 7 is connected to the reactor 3, before entering the reactor 3. Alternatively, it is also possible for both connecting lines 5, 1 1 to open into the reactor 3 and for the starting materials supplied via the connecting lines 5, 1 1 to come into contact with one another only in the reactor 3. This is particularly useful if a reaction is triggered immediately when the starting materials come into contact with one another.

The starting materials fed to the reactors 3 are preferably gaseous. However, it is also possible to supply liquid educts.

In the embodiment shown in FIG. 1, an outlet line 13 is additionally provided, which branches off from the connecting line 5. The outlet line 13 is used in particular to discharge part of the educt, so that the flow can be regulated by removing part of the educt from the process by adding an educt in excess and always withdrawing such an amount of educt via the outlet line 13 is that the desired amount is fed into the reactor 3. If a supply control takes place via the connecting line 5 or the further connecting line 11, the outlet line 13 can also be dispensed with.

The starting materials supplied via the connecting line 5 and possibly the further connecting line 11 are fed to the reactor 3, in which a chemical reaction takes place. The reactor 3 is preferably a continuously operated reactor, for example a tubular reactor. If the device is to be used for the investigation of catalysts or also for the investigation of reactions which are activated catalytically, the reactor 3 is filled with a catalyst. In the case of a tubular reactor, a catalyst bed 15 is usually introduced into the reactor 3 for this purpose. The starting materials fed to the reactor 3 then flow through the catalyst bed 15 and form a reaction mixture which gives the reaction product. if necessary contains by-products and possibly unreacted starting materials. If an inert gas is supplied to the reactor to dilute the reaction mixture, for example via the further distributor 9 or a third distributor not shown here, the reaction mixture also contains the inert gas, since this does not react with the starting materials supplied. If a gas containing moderator is fed to the reactor, the reactivity of the catalyst changes and the reaction mixture contains both unreacted or desorbed moderator and reaction products of the moderator.

After flowing through the reactor 3, the reaction mixture leaves the reactor 3 through a removal line 17. The removal line 17 can either open into a container in which the reaction mixture is collected, in order to be subsequently fed to an analysis, or it will be fed directly to an analysis unit 37, so that a so-called “online measurement” is carried out, by means of which even short-term fluctuations in the course of the reaction can be recorded. An analysis unit is used for the analysis, in which the reaction mixture can be examined qualitatively and / or quantitatively, for example by chromatographic methods such as gas chromatography or high-performance liquid chromatography or also by spectroscopic methods such as infrared spectroscopy, whereby combinations of different methods are also possible . The reaction mixture is usually fed to the analysis unit with the aid of a selection valve in order to be able to use the analysis unit for several reactors.

In order to supply the same starting materials to all reactors, the starting material distributor 7 is connected to a central starting material feed 25 via which the starting materials are fed to the starting material distributor and, if a further distributor 11 is present, it is connected to a further central inlet 27 via to which either further starting materials or also an inert gas are supplied and then, as described above, are distributed to the reactors 3 in the further distributor 11. If an outlet line 13 is provided on each reactor 3, these preferably open into a collector 29. The material flows collected and combined in the collector 29 are then removed from the process via a central outlet channel 31 from the collector 29.

In the device, several reactions can either be carried out simultaneously under the same conditions, it being necessary here in particular to feed the same reactant volume flows to all reactors at the same pressure, or under different conditions, for example to determine the influence of pressure and / or volume flow of an educt to investigate the reaction. In order to be able to set exactly the same volume flows at the same pressure or to be able to set different volume flows in a targeted manner, in one embodiment a restrictor and a pressure regulator are incorporated into the connecting line 5 between the feed distributor 7 and the reactor 3. FIG. 2 shows an embodiment with a back pressure regulator and FIG. 3 shows an embodiment with a back pressure regulator. For the sake of simplicity, only one reactor 3 is shown in FIGS. 2 and 3. In the overall device with several reactors, each reactor 3 is connected to the reactant distributor 7 in the same way. In contrast to the embodiment shown in FIG. 1, the embodiments shown in FIGS. 2 and 3 only have the educt distributor 7. In this case, all components fed to the reactor are fed to the reactors 3 via the feed distributor 7. For this purpose, the individual components are mixed in front of the educt distributor and then fed to the educt distributor 7 via the educt feed 25. The components can be mixed by any mixing device known to the person skilled in the art, as is already used for devices for analyzing reactions with several reactors connected in parallel.

In the embodiment shown in FIG. 2, a restrictor 19 and a secondary pressure regulator 21 are accommodated in each connecting line 5 between the reactor 3 and the educt distributor 7 as a pressure regulator. The restrictor 19 generates an essentially equal volume flow from the educt distributor 7 to the reactors 3. For this purpose, a pressure loss is generated in the restrictor 19 which is higher than the pressure loss in the pipelines and the rest of the system parts upstream of the restrictor 19 in the flow direction of the educts, starting from the distributor 7 and downstream up to the pressure maintenance. The pressure of the material flow supplied via the feed distributor 7 through the connecting line 5 is individually adjusted via the holding pressure regulator 21 before it enters the restrictor 19. For this purpose, the holding pressure regulator 21 is located between the educt distributor 7 and the restrictor 19. By setting the pressure in the material flow before entering the restrictor 19, the known flow resistance in the restrictor 19 can be used to set the exact volume flow of the material flow. For this purpose, a pressure measurement is carried out between the pressure regulator 33 of the secondary pressure regulator 21 and the restrictor 19, and if the measured pressure deviates from a specified target value, the pressure regulator 33, preferably a valve, is opened or closed further in order to set the pressure. If the pressure measured between the restrictor 19 and the pressure regulator 33 is lower than the desired setpoint, the pressure regulator is further closed to lower the pressure and opened accordingly at a measured pressure which is higher than the desired setpoint to reduce the pressure in the connecting line 5 before the restrictor 19. In this way it is possible to always feed the material flow to the restrictor 19 at a substantially the same pressure, so that the volume flow that is fed to the reactor 3 remains constant. Alternatively, it is of course also possible, if this is desired for the reaction to be investigated, to vary the volume flow, the predetermined setpoint for the pressure in the material flow being varied in accordance with the desired volume flow before entry into the restorator 19.

In the alternative embodiment shown in FIG. 3, the pressure regulator 33 is positioned between the restrictor 19 and the reactor 3. In this case, a pre-pressure regulator 23 is used, in which the pressure of the material stream that leaves the restrictor 19 is measured. Depending on the pressure measured at the outlet from the restrictor 19, the Pressure regulator 33 is set in order to obtain a predetermined pressure on the outlet side from restorre 19. In this way, the volume flow of the material flow fed to the reactor 3 can also be adjusted.

FIG. 4 shows an embodiment with an educt distributor and a further distributor for supplying educts or inert gases.

In contrast to the embodiments shown in FIGS. 2 and 3, the embodiment shown in FIG. 4 additionally includes the further distributor 9, which is connected to the reactor 3 by a further connecting line 11, the in the embodiment shown here being the further connecting line 1 1 opens into the connecting line 5 at a connecting point 35.

The further distributor 9 can be connected without a restrictor or pressure regulator. However, it is alternative and preferred to also provide a restrictor in the further connecting line 11. In addition, a pressure regulator can also be provided, in which case both the volume flow of the material flow supplied via the educt distributor 7 and the volume flow of the material flow supplied via the further distributor 9 can be set exactly. If an educt gas, rather than an educt gas, is supplied as a diluent gas via the further distributor 9, it is generally sufficient to provide a restrictor 19.

A restrictor 19 and a pressure regulator 33 are accommodated in the connecting line 5 for the exact setting of the volume flow. Here, the pressure regulator - as shown here - can be arranged between the educt distributor 7 and the restrictor 19. Alternatively, however, as shown in FIG. 3, the pressure regulator 33 can also be arranged between the restrictor 19 and the reactor 3, in which case the pressure regulator 33 is preferably a pre-pressure regulator.

If, in addition, a pressure regulator is provided in the further connecting line 11, this can also be positioned, as shown in FIGS. 2 and 3, either in front of the restrictor or behind the restrictor, with an upstream pressure regulator and an arrangement in front of the restrictor Positioning behind the restrictor a pre-pressure regulator is used.

If only a pressure regulator 33 is provided between the educt distributor 7 and the reactor 3 and no pressure regulator is positioned in the further connecting line 11 between the further distributor 9 and the reactor 3, it is also possible not to use the educt distributor 7 but via the to supply further distributors 9 and, for example, a diluent gas via the educt distributor 7. Usually, however, the educts are passed via the distributor 7 and / or 9, in which the material flow can be set precisely. The educts over the white Passing another distributor 9 and a gas containing moderator over distributor 7 is preferred if the influence of the amount of moderator on the reaction is to be investigated.

If educts are fed in both via the educt distributor 7 and the further distributor 9, it is particularly preferred if one restrictor 19 and one in each case in the connecting line 5 between the educt distributor 7 and the reactor 3 and in the further connecting line 11 between the further distributor 9 and the reactor 3 Pressure regulator 33 are added.

In the embodiments shown in FIGS. 2, 3 and 4, there is no outlet line for branching off part of the starting material. Depending on the reaction to be carried out, however, an outlet line as shown in FIG. 1 can also be provided. If the device is to be used to investigate various reactions, it is also possible to additionally provide a valve in the outlet line 13 with which it can be closed if no starting material is to be discharged from the device via the outlet lines 13.

Another alternative embodiment is shown in FIG. 5. In contrast to the embodiments shown in FIGS. 2, 3 and 4, in the embodiment shown in FIG. 5, the material flow fed to the reactor 3 is adjusted by adjusting the material flow drawn off via the outlet line 13. For this purpose, the restrictor 19 and the pressure regulator 33 are accommodated in the outlet line 13. In the connecting lines 5, 11 between the educt distributor 7 and the reactor 3 and, if present, between the further distributor 9 and the reactor 3, a restrictor and no pressure regulator is preferably contained, as shown here.

In this embodiment, the setting of the material flow supplied to the reactor 3 is not carried out directly but indirectly by setting the material flow which is taken off through the outlet line 13. For this purpose, the pressure regulator 33 is positioned between the reactor 3 and the restrictor 19 in the outlet line 13, the pressure regulator 33 being a secondary pressure regulator here. The material flow not supplied to the reactor 3 can be determined by the pressure measured in the outlet line 13 before entering the restrictor 19, so that the material flow supplied to the reactor 3 can be adjusted in this way on the basis of the pressure in the outlet line 13. As an alternative to the embodiment shown in FIG. 5, it is also possible to use a pre-pressure regulator to adjust the material flow, which is then positioned behind the restrictor 19 in the direction of flow.

FIG. 6 shows a further embodiment of a reactor of a device for analyzing reactions with two reactant feeds. In contrast to the embodiments shown in FIGS. 4 and 5, here the pressure regulator 33 is not accommodated in the connecting line 5 or 11 but in a common inlet line 39 in front of the reactor 3 and in the direction of flow of the fluids behind the connecting point 35 the connecting line 5 and the other connecting line 1 1 are merged. As in FIG. 5, an outlet line 13 is also possible here, but this is not always necessary depending on the tests to be carried out and the material flows supplied. If there are more than two educt streams, further educt distributors and connecting lines (not shown here) from the educt distributors into the reactor or to the connection point 35 can also be present. In the embodiment shown in FIG. 6, an inert gas can also be supplied via one of the connecting lines 5, 11 instead of a further educt. In particular, if changes in the partial pressure have no influence on the reaction carried out in the reactor, it is possible to dispense with a restrictor, at least in the connecting line through which the inert gas is supplied.

FIG. 7 shows a further embodiment of a reactor of a device for analyzing reactions with two reactant feeds. In contrast to the embodiment shown in FIG. 4, the restrictor 19 in the embodiment shown in FIG. 7 is positioned in the common feed line 39. This embodiment requires that a lower volume flow is supplied via the additional connecting line 11 than can flow to a maximum via the common inlet line 39, so that there is no backflow into the connecting line 5. It is advantageous in this embodiment that the total flow remains essentially constant with the same or comparable viscosity of the material flows from distributor 7 and further distributor 9 via the feed line 39 and only the composition of the total flow changes when the metered quantity exceeds the further connecting line 1 1 is changed.

Examples:

In a test setup with 3 parallel single metering lines analogous to that shown in Figure 3, an individual flow control was examined. The pressure pi in the reactant distributor was generated via a secondary pressure regulator upstream of the reactant distributor by metering corresponding amounts of nitrogen from the secondary pressure regulator upstream of the reactant distributor. The actual reactors were not installed and the respective outflow of the subsystem was measured in a time-resolved manner using a mass flow meter. A capillary with length L and inside diameter ID as a restrictor and a downstream pressure regulator (manufacturer "Pressure Control Solutions"; type: LF1 SNN12B-) were inserted into the individual metering lines (analogous to connecting lines 5 to the reactor in FIG. 3). NSMP1000T150G10VVB / Equilibar LF Series Precision Back Pressure Regulator) installed. The individual pressure behind the restrictor generated by this pre-pressure regulator is called p2 below. For individual tests, a further upstream pressure regulator (same equilibrium from Pressure Control Solutions) was installed at the outlet of the metering line to investigate the effect of a non-atmospheric reactor pressure. This pressure is called p ₃ in the following and is stated as 0 bar g for tests without this additional pressure regulator. For experiments on individual gas dosing, the corresponding pressure p1 was generated with nitrogen. The following experiments were carried out with capillaries of 1 m length and a nominal inner diameter of 80pm as a restrictor at room temperature (23-24 ° C). p _o is the ambient pressure p-term denotes the term: (pi ² -p2 ² ) / po.

Table 1: Investigation of the individual flow metering of nitrogen

The deviation of the flow regulation was 0.1% of the respective flow. Only in the case of high pressure differences of the admission pressure regulator for p ₂ , ie large difference p ₂ and p _3, could deviations in the flow control of max. 1% can be observed. For experiments on n-hexadecane flow regulation, a 100 ml container was integrated into the feed line of the educt distributor, which was filled with n-hexadecane. For the duration of the test, this filled container was pressurized with nitrogen, with regulation being carried out using the existing pressure regulator. The liquid streams from the individual metering lines were fed into test vessels, which were weighed out before and after the test. The corresponding mass flow delivered was determined by recording the dosing time and converted into a volume flow based on the density.

The following experiments were carried out with capillaries of 3 m length and a nominal inner diameter of 127 pm at room temperature (23-24 ° C).

Table 2: Investigation of the individual flow metering of n-hexadecane

The test examples clearly show that the flow dependence on the upstream and downstream pressure for a capillary (here 3m length 125pm internal diameter or 1m or 80pm) as a restrictor element for flows in the laminar flow regime surprisingly very well due to the known physical relationships for compressible media ( ideal gases; here nitrogen) or incompressible media (ideal liquids; here n-hexadecane) can be described. The result of this is that a prediction for the required upstream and downstream pressures for a desired flow is possible directly from a starting value without substance-specific or mixture-specific properties such as the temperature dependence of the viscosity having to be known. Another advantage results from the fact that the control quality is achieved by pressure control and measurement, so that if the control quality is too low, there is an increase in the flow resistance of the restrictor (for example lengthening a capillary) and a corresponding increase in the difference between the upstream and downstream pressure can achieve improved control quality.

Since the individual regulation of the flow takes place by checking the upstream or downstream pressure at the rest rictor through pneumatic lines and does not have to contain any electronic components, for example for flow measurement, the set-up can be operated at very high temperatures, so that the individual can also be operated Flow control for mixtures with very high dew points (for example hydrocarbon mixtures of medium boiling range evaporated under high pressures (for example up to 200 ° C.) or mixtures containing evaporated water with high water vapor partial pressures) is possible.

Likewise, it has surprisingly been shown on the basis of the experimental examples that, in addition to large flow changes by a factor of 10, small changes in the flow by 1% are also possible with a technical structure. Another aspect is that pressure changes can take place quasi ad hoc, whereas temperature changes are limited in time by the thermal mass of the respective structure and heat dissipation and supply.

Reference list

I device for analyzing reactions

3 reactor

5 connecting line

7 educt distributor

9 further distributors

I I further connecting line

13 outlet pipe

15 catalyst bed

17 Extraction line

19 restrictor

21 pressure regulator

23 pre-pressure regulator

25 educt feed

27 further inflows

29 collectors

31 outlet duct

33 pressure regulator

35 connection point

37 analysis unit

39 common supply line

Claims

1. Device for analyzing reactions, comprising a reactant distributor (7) and at least two reactors (3) connected in parallel, each of which is connected via a connecting line (5) to an outlet of the reactant distributor (7), characterized in that Adjustment of the inflow in each connecting line (5) between the feed distributor (7) and the reactors (3), a pressure regulator (33) and a restrictor (19) are included or that an outlet line (13 ) branches off, in which a restrictor (19) and a pressure regulator (33) are accommodated.

2. Device according to claim 1, characterized in that the pressure regulator (33) is a secondary pressure regulator and is accommodated between the educt distributor (7) and the restrictor (19).

3. Device according to claim 1, characterized in that the pressure regulator (33) is a pre-pressure regulator and is received between the restrictor (19) and the reactor (3).

4. Device according to one of claims 1 to 3, characterized in that the restrictor (19) is a capillary, a microstructured component, an aperture or a nozzle.

5. Device according to one of claims 1 to 4, characterized in that the

Reactors (3) are connected to a further distributor (9).

6. Device according to one of claims 1 to 5, characterized in that

a restrictor (19) is positioned between the further distributor (9) and each reactor (3).

7. The device according to claim 5 or 6, characterized in that between the further distributor (9) and each restrictor (19) or between each further distributor (9) downstream restrictor (19) and the subsequent reactor (3) Pressure regulator (33) is added.

8. The device according to claim 5 or 6, characterized in that the educt distributor (7) and the further distributor (9) are each connected to the reactor (3) by a connecting line (5; 11), the connecting lines (5, 11 ) are brought together at a connection point (35) and a common feed line (39) branches off from the connection point (35), which ends in the reactor (3) and the pressure regulator (33) in the common feed line (39 ) is included.

9. The device according to claim 8, characterized in that in the connecting line (5; 1 1) a restrictor is added.

10. A method for analyzing reactions in a device according to one of claims 1 to 9 in which each reactor (3) via the educt distributor (7) educts are supplied, the flow regulator of the educts being regulated via the pressure regulator (33) and an evaluator - The reaction product from each reactor (3) in the analysis unit.

1 1. The method according to claim 10, characterized in that at least one starting material via the starting material distributor (7) and at least one further starting material via the further distributor (9) are supplied.

12. The method according to claim 10, characterized in that the educt distributor (7) and the further distributor (9) are supplied with diluent gases or moderators containing gases.

13. The method according to any one of claims 10 to 12, characterized in that each reactor (3) is filled with a catalyst to be examined.

14. The method according to any one of claims 10 to 13, characterized in that the

Reactors (3) are loaded with different volume flows of starting material and / or different partial pressures and / or different compositions and / or different pressures.

15. The method according to any one of claims 10 to 13, characterized in that the

Reactors (3) are all loaded with the same volume flow and pressure.