Reactors in a microstructure arrangement

Abstract

The invention relates to a reactor with a multi-layer structure with a desired number of individual segments which are arranged on top of one another and / or next to one another and connected to one another and formed of diffusion-welded stacks of mictrostructured metal plates, in which the distribution channels for the cooling medium can be redirected at least twice, and wherein the cooling medium is initially introduced laterally in a cross-flow exclusively in end metal plates of the stack transverse to the flow direction of the process fluid and the cooling fluid is then redirected in the stack direction and distributed to multiple reaction regions within a segment; and a method for producing reactors, preferably (micro)structured reactors, comprising levels for the through-flow of reaction medium and the through-flow of heat transfer medium.

Description

[0001] Microstructure reactors

[0002] All documents cited in the present application are incorporated by reference in their entirety into the present disclosure.

[0003] The present invention relates to a reactor with a multi-layer structure with a desired number of individual segments arranged on top of one another and / or next to one another and connected to one another, made of diffusion-welded stacks of microstructured metal plates, in which the distribution channels for the cooling medium are preferably deflected at least twice, and wherein the cooling medium is preferably first introduced laterally in cross-flow exclusively into regions resulting from end metal plates of the stacks transversely to the flow direction of the process fluid and then the cooling medium is deflected in the stack direction and distributed over several reaction regions within a segment, and to a method for producing reactors, preferably (micro-)structured reactors, comprising levels for, on the one hand, flow of reaction medium and, on the other hand, flow of heat transfer medium

[0004] State of the art:

[0005] In (micro-)structured reactors, solid catalysts can be introduced as layers or as particle fillings. Such reactors are typically used for fast and high-energy reactions. A layered structure, i.e., alternating layers with flow of reaction medium and heat transfer medium, ensures efficient heat inflow or outflow, thus allowing the reaction to operate at a temperature setpoint as close as possible.

[0006] When loading such microstructured reactors, it is known that it is important that all structures, whether slot- or channel-shaped, are uniformly flowed through. In addition to the influence of manufacturing tolerances on the effective hydraulic diameter, which significantly influences the flow resistance and thus, in turn, the volume flow into the respective parallel structures in the case of a shared inlet and outlet (Pfeifer et al., Characterization of flow distribution in microchannel reactors, AIChEJ, 418-425, 2004), the flow conditions on the multitude of structures are also relevant for the uniform application of working fluid (Pfeifer et al., Hot wire anemometry for experimental determination of flow distribution in multilayer microreactors, Chem Eng J 135S (2008) pages 173-178).If the parallel structures are filled with catalytically active material, a particle size distribution that is as narrow as possible is advantageous, so that the local porosity is as identical as possible throughout the entire particle cluster, thus enabling a uniform distribution of the mass flow across the parallel structures. With a correspondingly high pressure drop in the particle cluster, external flow conditions become almost irrelevant for the uniform distribution.

[0007] This is also described in US 10,335,759 B1, in which ultrasound and fluidization of the particle aggregate are used to achieve the most homogeneous distribution of the catalyst particles. However, the size of the channels into which the particles are introduced is also an equally important factor for the uniform distribution of the material flow, as are the parallel channels for cooling or heating the reaction. In a particle-filled channel, the ratio of volume in which particles are in wall contact to volume in which particle-particle contact exists increases as the channel becomes smaller. This is particularly true for a channel-to-particle size ratio of 2-10, which can occur in microchannels. This means that even under conditions where the particle aggregate becomes a major influencing factor, the size tolerance of the channels themselves influences the uniform distribution.This is especially true for very fast reactions where a very short residence time is required and the catalyst bed length is rather short. If some adjacent channels for cooling or heating the reaction are smaller than others, this results in less material flow at these points for thermostatting the reaction, which can negatively impact the desired temperature or temperature profile in the reactor.

[0008] In the manufacture of microstructured reactors, the parallelization of channels optimized for heat and mass transfer leads to an increase in throughput. Ideally, the throughput increases with the number of channels, provided that the material flow is evenly distributed. It is clear that when parallelizing the channels, heat transfer to neighboring channels must always be considered, as these also require a medium supply. Crossflow design is usually the most suitable, as this design allows connection to the side surface of the reactor. Corresponding designs are known from many patents, see also DE 10 2005 022 985 and US 5,249,359. The supply of coolant in countercurrent or cocurrent design geometrically forces a relatively large area of ​​crossflow of channels, in which heat transfer already occurs.The coolant temperature increases from the inlet of the heat transfer medium to the point where the countercurrent or cocurrent flow is to be established. Therefore, the supply of coolant of the same temperature to the countercurrent or cocurrent flow depends on the number of reaction channels that cross over in the design. This is particularly problematic for very fast reactions with high heat of reaction. This problem is made even more problematic by a targeted reduction in pressure drop in microchannels with a packed bed by shortening the bed length and thus also a shortening of the heat exchange zone. Therefore, the increase in the external dimensions of a plate pack with microchannels for reaction and integrated cooling is severely limited in both width and length.

[0009] Since the plate stack also has a height limitation, parallelization of reactor modules is often proposed. This limitation arises from the module's joining technology, either due to increasing stresses when welding multilayer stacks of metal plates using a blasting process or due to the consumption and possible shearing of a metal plate stack due to the force acting on the stack during diffusion welding.

[0010] The need to use a large number of reactor modules to achieve high plant capacities has disadvantages regarding the required piping and the flow to individual reactor modules. Due to cost advantages for pumps or compressors with scaling throughput, a common supply to the individual modules is advantageous. US 2014 / 0357738 A1 therefore proposes integrating the individual metallic reactor modules into a common pressure vessel, in which the individual connection areas of the channels are internally sealed against the distribution chambers.

[0011] During the manufacture of the individual reactor modules and the microchannels created on the plates or via cutouts, tolerances in size are to be expected, particularly when using a large number of individual plates due to the rolling of the plates and the joining of the plates using individual diffusion welding processes. As described above, this leads to a possible uneven distribution of the process fluid or coolant.

[0012] Further prior art that could be mentioned are EP 3 463 642 B1 (in which, if several reactors are used, these are connected in series), DE 103 39 972 A1 (in which connections are obtained by laser welding); or possibly (more distantly related) DE 60 2004 009 360 T2, DE 103 18 257 A1, EP 1 352 686 A1, DE 10 2004 037 059 B4.

[0013] In this respect, based on the known state of the art, there is still a considerable need to improve the current state of the art.

[0014] Task:

[0015] The object of the present invention was therefore to overcome the disadvantages of the prior art described above and to provide reactors which no longer have these problems or at least only to a considerably lesser extent.

[0016] The aim was to find a reactor design that avoids the disadvantages of the state of the art and improves the known reactors.

[0017] In addition, a manufacturing process should be found with which such reactors can be manufactured comparatively easily, safely and economically.

[0018] Further tasks will become apparent to the person skilled in the art when considering the claims and the following description.

[0019] Solution:

[0020] These and other objects, which will become apparent to the person skilled in the art from the present description, are achieved by the subject matter presented in the claims, with the dependent claims representing preferred and particularly advantageous embodiments. Within the scope of the present invention, the reactor front side is understood to be the side from which the reaction medium / fluid flows into the reactor, and the reactor rear side is understood to be the side from which the reaction medium / fluid exits the reactor.

[0021] Description:

[0022] The present invention particularly relates to a process for producing reactors, preferably (micro-)structured reactors, comprising levels for, on the one hand, flow of reaction medium and, on the other hand, flow of heat transfer medium.

[0023] In step a), structured metal plates, each with the same width and depth for the respective levels, are first stacked on top of each other. The metal plates preferably have edge lengths of 20 cm to 200 cm. In preferred embodiments, the metal plates have thicknesses of 0.3 mm to 12 mm.

[0024] In optional embodiments, which are preferred in some variants, structured or non-structured metal plate(s) are stacked as the top and / or bottom end metal plate (or sometimes called metal end plate or end plate).

[0025] The orientation of the metal plates, in particular the classification of what constitutes the front and back, or what constitutes the sides of the individual metal plates, results from the structure of the metal plates that form the reactor structure itself, through incorporated reaction channels or groups of reaction channels. This is because the reaction medium flows through the reactor structure (reaction channels) from one side – the front – to the other side – the back. The orientations of the other metal plates necessarily result from the metal plates that contain the reactor structures. This is readily known to the person skilled in the art.

[0026] In the next process step b), the stacked plates are bonded together by diffusion bonding. In preferred embodiments of the present invention, the height of the plate stacks in this context is a maximum of 1.5 times greater than the longest edge length (for example, with an edge length of 20 cm, the stack would be a maximum of 30 cm high).

[0027] Next, in step c), the diffusion-bonded stack thus obtained is divided widthwise into individual segments, each of equal depth. In some preferred embodiments of the present invention, the individual segments have a depth of between 3 cm and 30 cm, in others a depth of between 3.5 cm and 32 cm. It should be noted here that the reaction medium can also be deflected between these two sides and does not necessarily flow in a straight line between the two sides. In addition to strictly straight reaction channels, reaction channels in other configurations are also conceivable, preferably jagged, undulating or meandering, with loops. However, straight reaction channels are most preferred, especially for reactions with a short residence time.

[0028] In some embodiments, the depth of the segments corresponds to the distance between the front and rear of the reactor.

[0029] This is particularly true when structured metal plates are used in which the reaction channels extend right up to the edge of the plate. This also applies when structured metal plates are used in which the reaction channels do not extend right up to the edge of the plate and the front and rear sides of the segments must first be milled down after production until the reaction channels are reached, but the edge area is not milled and a circumferential edge is left (this promotes stability and is ideally suited to supporting flange connections for the shared supply of reaction medium). This procedure is preferred according to the invention because, among other things, it offers a good compromise between ease of production, stability and functionality. This milling can be carried out either before or after step d) described below.In some embodiments, it is useful and therefore preferred to mill after step d), since then any unevenness from the connection of the segments can be compensated.

[0030] However, this does not apply if structured metal plates are used in which the reaction channels are not led to the edge of the plate and the front and back sides of the segments must first be milled down after production until the reaction channels are reached, and in the process the surfaces are completely milled and no peripheral edge is left.

[0031] Then, in the next method step d), a desired number of individual segments obtained in the previous step are arranged on top of one another and / or next to one another and connected to one another. Preferably, a lower end plate of one segment is arranged on top of an upper end plate of another segment if the sequence of the plates in the stack is symmetrical, i.e. the sequence from bottom to top does not differ from a view from top to bottom. In other variants, an upper end plate can be arranged on top of an upper end plate of another segment or a lower end plate can be arranged on top of a lower end plate of another segment; this makes a difference if the sequence of the plates in the stack is different. In some preferred embodiments, only one arrangement occurs on top of the other.The connections can be made by any method, but are preferably selected from screwing, clamping, gluing or circumferential welding, in particular by circumferential welding.

[0032] So, on top of each other means that the segments are arranged end plate to end plate and next to each other means side by side.

[0033] It should be noted that when manufacturing individual segments by diffusion welding, a maximum height of three times the segment depth is almost impossible to overcome due to the process (i.e., reactors that are no longer usable would be created) or would lead to severe warping of a segment. If the height of the plate stack is 1.5 times greater than its width as the largest side length and, for example, 5 segments are arranged on top of one another in step d), the result is a factor of 7.5 for the maximum height of the assembled reactor compared to its width. In preferred embodiments of the present invention, recesses are machined into the metal plates or the stack before or simultaneously with step c), preferably before step a), along which the division then takes place in step c).Preferably, these can be produced by etching, milling, punching or other means; in some (further) preferred variants, by punching.

[0034] The position of this row of recesses defines the segment depth in the finished product.

[0035] In some preferred variants of the present invention, punched-out sections are incorporated at the same height as the recesses on the sides of the metal plates or on the sides of the stack. This further facilitates separation into segments.

[0036] To make division easier, the recesses are preferably as long and narrow as possible, but should not exceed a certain length. The maximum length is based on the desired width of individual reactor sections (i.e. respective groups of reaction channels, which can also be referred to as (reactor) modules, even if they only refer to a respective structured metal plate), i.e. the width of the respective reactor openings (respective groups of reaction channels) as specified in the metal plates. It is preferred if the reaction zones resulting from the reactor sections in the finished reactor, considered individually, can still be easily cooled in parallel or cocurrent flow. In some variants, the length of individual recesses is a factor of 2 smaller than the depth of the segment. In particularly preferred embodiments, the lengths of the recesses are in the range of 1.5 to 15 cm.In preferred embodiments of the present invention, one or, more preferably, two or more of these recesses are incorporated into the metal plates or the stack, wherein the ratio of the sum of the recess lengths to the total width of the metal plates is preferably from 60% to 90%, more preferably 30% to 70%. In some preferred variants, two or at least two recesses are incorporated, since in these variants it may also be a matter of achieving parallelization of individual reactor modules incorporated in the plates. In preferred embodiments of the present invention, a ratio of segment depth to recess length (= width of the reactor module) of 2 to 8 is maintained. The reaction zone length (length of the reaction channels) is also preferably greater than an individual recess length, i.e. the relevant width of a reactor section.In some preferred embodiments, at least one recess is located "above" each reaction zone in the respective metal plate. The recesses are preferably so long that all channels of a reactor module lie within this recess, i.e., the recess length is greater than the width of the region in which the channel outlets are located (i.e., greater than a module width). The total width, as the sum of all recess lengths and the intermediate regions, is nevertheless significantly greater than the reaction zone length due to the number of reaction zones in a segment (section), particularly if the segments (sections) have more than two recesses or reactor modules.

[0037] In preferred embodiments of the present invention, the metal plates used in step a) have an approximately square, preferably exactly square, shape. Approximately square means an aspect ratio of 1:2 to a maximum of 2:1, preferably from 1:1.3 to 1.3:1, more preferably 1.15:1 to 1:1.15, particularly preferably 1.1:1 to 1:1.1, and especially preferably exactly an aspect ratio of 1:1. Of course, manufacturing tolerances can lead to a slightly different aspect ratio.

[0038] In further preferred embodiments of the present invention, the connecting points of the individual segments obtained in step d) are planarized with one another to produce flat sealing edges, in the case of circumferential welding in step d) preferably by milling the resulting weld seams.

[0039] In further preferred embodiments of the present invention, the structured metal plates have an edge around their structuring on all sides (among other things so that fewer deformations occur during diffusion welding), and after step c) or after step d), preferably after step d), a step f) ("f" as in milling) is performed, in which the front and back sides of the segments are milled out down to the openings of the reaction channels. The milling can be performed over the entire surface or in such a way that a circumferential edge remains in the resulting reactor. The circumferential edge is preferably somewhat thinner than the side edge of the structured metal plates (there is still a (small) margin between the lateral end of the respective structuring and the inside of the circumferential edge).

[0040] In still further preferred embodiments of the present invention, the flat sealing edges are each adapted with a flange or all together with a flange or partly, partly.

[0041] In preferred embodiments of the present invention, the end metal plates are selected and designed such that the cooling medium can be introduced into their interior in a crossflow pattern perpendicular to the flow direction of the process fluid. The coolant channels in the end metal plates are further configured such that the cooling medium is redirected parallel to the stack height of the segments.

[0042] It is further preferred that at least two deflections of the cooling medium occur within the distribution channels in the reactor. In particularly preferred exemplary embodiments, the first cross-flow region is achieved with channels measuring 5 mm to 20 mm. In these embodiments, the sub-distribution in the stacking direction, spatially viewed next to the individual reactor modules, occurs via channels measuring 2 mm to 10 mm and, after the second deflection, back to cross-flow, then with channels measuring 2 mm to 5 mm. The actual channels for thermostatting, which run parallel to the reaction channels, typically have a diameter and / or edge length of <2 mm in these embodiments.

[0043] In preferred embodiments of the present invention, the end metal plates are selected so that the cooling medium can flow cross-flow through regions not close to reaction channels. The term "closeness" here preferably means a distance of at least 5 mm, preferably between 5 mm and 10 mm.

[0044] In preferred embodiments of the present invention, the end metal plates, if present, have a thickness of equal to or greater than 5 mm, preferably 10 mm, and / or less than 80 mm, preferably 70 mm; particularly preferably between 10 mm and 70 mm, in some other embodiments between 10 and 40 mm, and inlet openings for cooling medium. These inlet openings can have a diameter of 5 to 20 mm in some preferred embodiments (of course, the diameter of the inlet openings must be adjusted depending on the plate thickness so that the plates and openings or channels are stable and closed; this is readily apparent and adaptable to one skilled in the art).

[0045] Further preferred embodiments consist in that the end metal plates have holes at the same locations.

[0046] In some preferred embodiments, heating elements are also inserted in the stacking direction. For this purpose, in preferred embodiments, round recesses are already provided in the end plates and the plate elements, which can be further drilled out after diffusion welding and after the segments have been joined, if necessary, in order to achieve a high degree of precision fit between the heating element and the metal plates in the event of deformed cutouts due to diffusion welding and due to possible offset when connecting the segments. Alternatively, but usually less preferred, it is also possible within the scope of the present invention to machine through-holes only after the segments have been joined together. The round recesses are each arranged such that they lie next to or between the reactor zones, i.e. such that no connection to the branches of the cooling channels is created.

[0047] A further subject matter of the present invention is, in particular, a reactor which is characterized in that it comprises a desired number of individual segments arranged one on top of the other and / or next to one another and connected to one another, in particular one on top of the other, wherein a lower end plate of one segment is arranged on an upper end plate of a further segment, made of diffusion-welded stacks of microstructured metal plates, in which the distribution channels for the cooling medium are deflected at least twice, and wherein the cooling medium is first introduced laterally in cross-flow exclusively into end metal plates of the stacks transversely to the flow direction of the process fluid, then the cooling medium is deflected in the end metal plates in the stack direction and distributed over several reaction areas within a segment.

[0048] The reactor according to the invention is preferably produced according to the process described above.

[0049] Last but not least, the present invention particularly relates to the use of a reactor according to the invention or a reactor produced by the process according to the invention for Fischer-Tropsch reactions or methanation reactions.

[0050] With regard to the present invention and its advantages, the following can be stated:

[0051] Compared to several smaller individual modules, enlarging the plate dimensions and thus the entire welded body is advantageous in order to reduce the influence of tolerances due to the rolling process of the plate base material as well as compared to several individual diffusion welding processes of individual modules. However, this is not easily possible due to size limitations. Since for very fast reactions the reactor width usually has to be significantly greater than the reactor length, individual segments are rectangular in shape. According to the invention, several such shapes are arranged in series until an approximately square shape is achieved for diffusion welding and separated into individual sections after the diffusion welding process. Due to the square shape, the plate stack can be higher than with a rectangular shape (the risk of shearing is reduced), which is advantageous for the number of reactor modules.By rotating the individual cut-off segments by 90° to each other, an even greater stack height can be created by arranging them in a row and corresponding circumferential welding at the contact surfaces, whereby the process fluid can enter and exit the exposed channels at the resulting end faces. The invention also includes the introduction of punched out sections at the points where the welded body is separated in order to facilitate separation. The cutouts should be as narrow and long as possible; the ideal ratio of the cutout length to the total width of the plates should be 30-70%. Furthermore, there should preferably be at least two cutouts rather than a single one. A ratio of reaction zone length to cutout length of 2 to 8 has proven particularly suitable for preventing the plate stack from becoming swollen in the cutouts.Since all segments are created from a single plate stack, tolerances from the rolling process and the diffusion welding process are reduced. Even if the same welding parameters result in different deformations of the individual plate stacks (inaccurate temperature measurement at high temperatures, deviations in the steel structure, etc.), circumferential welding allows the resulting entire body to be adapted at the end faces after milling the weld seams to create flat sealing edges with a flange each, thus significantly reducing the effort required for connections compared to many individual modules.

[0052] In order to achieve the largest possible reactor width, the cooling medium can be diverted at least twice within the largest possible distribution channels, with the cooling medium initially being introduced laterally (crossflow) and exclusively into the end metal plates, perpendicular to the flow direction of the process fluid. It is then diverted in the stacking direction and distributed among several reaction zones within a separate reactor segment. The channeling in the end metal plates, which in preferred embodiments have a thickness of 10 mm to 40 mm, as well as the guidance in the plate stacking direction in zones without reaction channels, prevents any significant heat exchange until the cooling medium enters the individual plates of the cooling channels. A correspondingly high ratio of the length of the catalyst bed to the width of the reaction zone ultimately ensures that the countercurrent / cocurrent zone is maximized.If the end metal plates of the reactor segments are positioned against each other as described above, the heat input into the cooling medium supply lines is minimal.

[0053] With the present invention, a maximization of the reactor size can be achieved with very short reaction channels in the range of 2.5 cm to 28 cm or even from 3 cm to 30 cm in length (these sizes correlate with the above-mentioned depths of the individual segments, depending on whether (over)milling is (must be) carried out or not - if milling is necessary, the segment depths are slightly larger than the reactor channel lengths).

[0054] The present invention is therefore based in particular on an optimized manufacturing process for parallelized multiple modules, which could not be derived from the prior art, and it was particularly surprising that the inventive procedure (and resulting products) led to excellent results.

[0055] With the present invention, the limitations of reactor size regarding reactor width and stack height are significantly reduced for reactions with very short residence times, i.e., very short reaction zones. At the same time, the distribution of coolant flows and the uniform distribution of the process fluid are optimized.

[0056] Within the scope of the present invention, in particular the preferred embodiments, a parallelization of several modules for very short residence times is achieved without the need for control valves or residence elements. By means of the present invention (i.e., in particular the parallelization of modules, which are initially created by separating the modules from a stack of plates and in which one of the material flows is distributed across the modules by rotation through 90° with subsequent connection technology), the fundamental difficulties in constructing overall large apparatus with very short side lengths (see above) are avoided or eliminated. The manufacturing "trick" according to the present invention results in significant economic advantages for plant engineering in the elimination of such valves.

[0057] The person skilled in the art can, within the scope of his general technical knowledge, determine the exact design of the devices described, such as size, wall thicknesses, materials, etc., to suit the reaction conditions envisaged for a specific reaction, unless these are explicitly described in this description.

[0058] If, in the description of the devices according to the invention, parts or the entire device are marked as "consisting of," this is to be understood as referring to the essential components mentioned. Self-evident or inherent parts such as lines, valves, screws, housings, measuring devices, storage containers for reactants / products, etc. are not excluded.

[0059] Unless explicitly described, the individual parts of the devices are operatively connected to one another in a customary and known manner.

[0060] The various embodiments of the present invention, for example - but not exclusively - those of the various dependent claims, can be combined with one another in any desired manner, provided that such combinations do not contradict one another.

[0061] The present invention is explained in more detail below with reference to the drawings. The drawings are not to be interpreted in a limiting sense and are not to scale. The drawings are schematic and, furthermore, do not contain all features found in conventional devices. Instead, they are reduced to the features essential to the present invention and its understanding. For example, screws, connections, etc., are not shown or are not shown in detail. The same reference numerals indicate the same features in the figures, the description, and the claims.

[0062] In the context of the following explanations, some variants or advantageous and preferred variants / embodiments are also presented which, unless otherwise stated, are not limited to the respective figure described, but are preferred variants of the present invention per se (unless contradictory).

[0063] Figure 1 shows a reactor 1a according to the invention, in the form of a stack 2 of structured metal plates arranged one above the other, with metal end plates 3 at the top and bottom. The plates are all diffusion-welded. The reactor is shown before being separated into the individual segments 6 (in the example shown, there are three). Also visible are punched-out areas 4 along which the segments 6 are separated from one another; not visible here are the recesses 5, which are also provided for separation, since these are not present in the cover plates, but only in the stack plates (metal plates) in between (see also Figures 4 and 5). Also indicated are reactor openings 10 in the individual structured metal plates. If desired, catalyst can be arranged in these during reactor operation. Furthermore, holes 7 for heating elements are shown in the metal end plates.Also visible are the inlet openings 8 for the cooling medium, which are located here on the side of the end metal plates 3.

[0064] It should be noted that Figure 1 shows an embodiment in which structured metal plates are used for the stack 2, which have reactor openings 10 on the front side (and on the back side, not visible in the figure). However, from a production point of view, it is sometimes advantageous, and therefore preferred in variants of the present invention, if the structures are not extended all the way to the edge, but rather the edges of the metal plates are continuous (this leads to less deformation during diffusion welding, or the diffusion welding can be carried out with more pressure and / or less care at the edge).

[0065] Although it is preferred according to the invention to separate the individual segments 6 from one another, rearrange them, and then use the new arrangement as a reactor, it is also possible to use the reactor 1a shown here as such in this form; in contrast to the more preferred embodiments according to the invention, such a reactor would have comparatively long or deep reactors (in the example shown, three times as long as when the segments are separated).

[0066] Figure 2 shows a reactor 1b according to the invention, in which the individual segments 6 were separated from one another by separating them along the punched-out portions 4 (and the recesses 5 not shown) in the reactor 1a, and then rearranged one above the other. These segments, shown here lying horizontally, are now designated segments 6' for differentiation (they are the same segments, just separated from one another). It can be clearly seen that the rearrangement of the segments results in many more reaction channels (reactor openings 10) in the reactor 1a. For reactors for rapid reactions, the shallow depths with correspondingly short reaction channels are usually sufficient. The holes for heating elements 7 can be seen here again. Also visible are the inlet openings for cooling medium 8.In the reactors of the present invention, the reaction medium channels naturally run through the entire reactor 1a / 1b and do not merely represent bores in the metal end plates 3. Reference 3' in Figure 2 represents the inner surfaces of the stacks 2 after milling. As can be seen, the edges (obliquely at the top left and diagonally at the bottom right in the image) have been left standing, resulting in a kind of peripheral edge into which screw holes 9 have been machined (to which flanges, etc., can be attached; for example, a flange for a reaction fluid supply device). Due to the production by diffusion welding, the end metal plates 3 in this image can no longer be clearly separated from the peripheral edge (transition not recognizable). Also clearly visible are various preparations for connections 15, which here are designed as screw holes or notches.These can be used to connect the individual segments 6' to each other, or to connect the finished reactor 1b to other workpieces.

[0067] It should be noted that Figure 2 shows a variant of the present invention in which the individual metal plates of the stacks 2 originally had no structures at the edge when joined by diffusion welding; only after tilting (and preferably after joining together) were the individual stack segments 6' milled down to the depth of the reactor openings 10, leaving a peripheral edge (i.e., not milled on the outside), into which, for example (as shown here), screw holes 9 (or similar) can then be machined.In this way, the preceding diffusion welding can be carried out more easily / effectively, and a uniform surface 3' is obtained by the subsequent milling, so that the arrangement of the supply nozzles can then be better and / or more precise and / or the distribution of reaction medium can be more uniform; in this respect, this is a preferred variant of the present invention.

[0068] Figure 3 shows a reactor 1c according to the invention, very similar to Figure 2, but with a slightly different detailed design and representation. In contrast to Figure 2, heating element ends 7a can be seen here, of heating elements that have been pushed through the reactor (i.e., through the holes 7 for the heating elements). Depending on the design of the heating elements, power connections can be provided at the protruding ends of the heating elements 7a shown in Figure 3, for example, in the event that the heating elements are based on electricity. In the embodiment according to Figure 3, a common, flat sealing surface 21 is also placed over the three individual segments, which sealing surface was placed on the edges of the previously machined (internally milled) segment surfaces 3'.In this common, flat sealing surface 21, screw holes 9 can again be seen, which of course correspond to the screw holes 9 arranged below them, which were machined into the partial / end metal plates or sides of the segments 6'. This sealing surface 21 can essentially be made of the same material as the metal plates of the reactor or can be made of other materials (particularly) suitable for sealing. In this respect, it is certainly possible to use materials such as Teflon for this purpose. Furthermore, this figure illustrates a variant in which the inlet openings for cooling medium 8 (which are therefore no longer visible in this figure) are connected to one another via (for example, welded-on) half pipes 13. In this way, it is possible, for example, to supply both inlet openings for cooling media at the same height of a segment via just one coolant supply.For this purpose, for example, the (screw) connections for cooling medium supply 14 illustrated here can be used. Although Figure 3 illustrates three stacked half-pipes 13 with respective (screw) connections for cooling medium supply 14 in each segment, these half-pipes can also be replaced by other configurations. For example, instead of the three individual half-pipes 13, it is just as possible to arrange a type of hood over the side of each segment 6', whereby this hood then covers, for example, all inlet openings for cooling medium 8, and then to provide this hood with only one (screw) connection for cooling medium supply 14. Other corresponding configurations are also possible. In addition to the reactor openings 10 visible again in this figure, the connection points between the individual segments 6' can also be seen, here with the reference number 12.In this case, these represent circumferential welds connecting the individual segments 6'. These circumferential welds 12 have, of course, been leveled by milling down the stack surfaces. If the surfaces are not milled down, it is preferable to mill or level such circumferential welds to obtain the most uniform surface possible (this is advantageous for further processing, handling safety, and the distribution of reaction medium).

[0069] Figure 4 shows an example of a structured metal plate 16 in plan view. This is an exemplary structured metal plate, such as can be used, for example, in the manufacture of reactors 1a, 1b or 1c, with the difference that, for the sake of simplicity, only two segments 6 are shown in Figure 4 and not three segments as in Figures 1, 2 and 3. The present invention is of course limited neither to two segments nor to three segments 6, but the reduction to two or three segments 6 merely serves to simplify the illustration. Nevertheless, in various preferred variants of the present invention, it is preferred if two segments 6' or three segments 6 are used. This figure shows various bores in the structured metal plate 16. These bores have two different diameters.The smaller diameters, twelve of which are visible per segment (in three groups of four), are illustrated with the number 7 and represent the holes for heating elements 7. These holes therefore pass through all of the structured metal plates to be arranged one above the other at the same location; the structured metal plates 16 (and others) to be used accordingly must be manufactured accordingly, and it must be ensured that the holes lie one above the other - if heating elements are to be guided through the reactor. In this context, it should be noted that, within the scope of the present invention, it is not mandatory for heating elements to be guided through the reactor; this is merely one (of many possible) variant, and in this respect, the holes / bores 7 are optional within the scope of the present invention and only absolutely necessary if heating elements are to be used.Regardless of the actual use of heating elements, it is preferred in variants to provide holes 7 to ensure flexibility in the application of heating elements (moreover, in some variants, (heated) air can simply be directed through the holes or the channels formed therefrom). The other, larger holes, designated 11a, represent openings for coolant channels perpendicular to the planar plane; the channels themselves are formed by arranging several structured plates, which are not necessarily identical, one on top of the other – in this respect, too, care must be taken to ensure that the stacked plates are coordinated or adapted to one another with regard to the structures for the coolant (channels) (this will be clear to the person skilled in the art).Coolant can then flow through these openings 11a (if used - applications are also conceivable in which no coolant needs to be passed through - the reactors according to the invention can of course also be used for such applications). Also shown in this figure are the punched-out portions 4 and the recesses 5, along which the two segments 6 can then be separated from one another. The recesses 5 have a corresponding recess length A, which in the example shown (a preferred embodiment) essentially corresponds to the width B of an individual reactor module, i.e. the respective reactor channels arranged next to one another in a section. In this figure, R also represents the reaction zone length of the respective reactor modules. Furthermore, T indicates the depth of the respective segments 6.The figure shows a structured metal plate 16 in which the structures do not extend to the edge (upper and lower edges in the figure) (the depth T of the segments 6 is significantly greater than the reaction zone length R of the individual reactor modules). This means that after the individual segments 6 have been separated from one another (tilted by 90°) and joined together, the surface of the stacks must then be milled down until the reactor openings are reached. This represents a preferred embodiment of the present invention; however (as already mentioned), it is entirely possible within the scope of the present invention to extend the structures of the individual reactor modules in the structured metal plates right up to the respective edge of the metal plates, which would then make milling down unnecessary.

[0070] It should be noted that, within the scope of the present invention, it is not mandatory that the surfaces of the segments 6' be machined by milling to reach the openings of the reactor modules. Other known methods for surface removal can also be used. However, milling is usually preferred due to practical considerations.

[0071] Figure 5 shows, in a view obliquely from above, various structured metal plates (16, 17, 18, 19, 20) as they can be arranged one above the other to form (part of the) stack 2 of structured metal plates. The structured metal plate 16 corresponds to the one shown in Figure 4. In the context of Figure 5, for this structured metal plate 16, L' also illustrates the area along which the reaction fluid will flow (in the finished reactor, from bottom to top along the linear reactor module structure). Here, too, the recesses 5 or punched-out sections 4 are illustrated in the various structured metal plates, along which the individual segments 6 will later be separated from one another. The structured metal plate 20 represents a transition plate which can be structured differently as required, so that a precise structuring is not shown in this example. 11a again denotes bores orCoolant channels are shown perpendicular to the respective plate plane. 11b also denotes coolant channels in the respective plate plane. In the structured metal plate 19, the coolant channels 11a are connected perpendicular to the plate plane with the coolant channels 11b located in the plate plane. In this respect, coolant can enter the plane via the coolant channel 11a and then flow along the coolant channels 11b in the plane. The coolant can then reach the next plane, in this case the structured metal plate 18, via this coolant channel 11b (in the illustrated variant, corresponding structures located in the plate plane are also provided in the metal plate 18 - but this is not necessarily always the case). In the structured metal plate 17 that follows, L illustrates an area of ​​the longitudinal flow of the cooling fluid, i.e., in this plate, the cooling fluid is deflected and then flows, for example,vertically in the plate plane. In this respect, with appropriately designed structured metal plates, it is possible to introduce the cooling medium coming from an underside (or top side) of the reactor into the stack 2 of structured metal plates in the reactor, where it can then be redirected in different directions by various deflections in the respective plate planes in order to achieve the best possible cooling medium distribution. (Partial) cross flows, which are illustrated here with K for a cross flow region, can be provided. It should be noted that the sequence of structured metal plates illustrated here or the exact structure of the metal plates shown is merely an example and the present invention is of course not limited to the sequences of structured metal plates shown here or the structures shown.List of reference symbols: la reactor (before separation of the segments) lb reactor (after separation and rearrangement of the segments) lc reactor (after separation and rearrangement of the segments; other design).

[0072] 2 stacks of textured metal plates

[0073] 3 metal end plates (non-structured, only provided with inlet openings for cooling medium)

[0074] 3' stack surfaces after milling down

[0075] 4 cutouts

[0076] 5 recesses

[0077] 6 segments

[0078] 6' segments, lying (after separation)

[0079] 7 holes for heating elements

[0080] 7a (visible parts of) heating elements

[0081] 8 inlet openings for cooling medium

[0082] 9 screw holes (for attaching flanges)

[0083] 10 reactor openings

[0084] 11a Coolant channel perpendicular to the plate plane

[0085] 11b Coolant channel in the plate plane

[0086] 12 circumferential welded joints

[0087] 13 half pipes (welded on, connecting the inlet openings for the cooling medium)

[0088] 14 (screw) connections for cooling media supply

[0089] 15 Preparations for connections (screw holes, notches, etc.)

[0090] 16 structured metal plate

[0091] 17 structured metal plate

[0092] 18 textured metal plate

[0093] 19 structured metal plate

[0094] 20 textured metal plate

[0095] 21 common, flat sealing surface (with screw holes 9)

[0096] A Recess length

[0097] B Width reactor module

[0098] K Cross-flow area

[0099] L Longitudinal flow of the cooling fluid L' Longitudinal flow of the reaction fluid

[0100] R reaction zone length

[0101] T Depth of segments 6

[0102] Example:

[0103] The invention will now be further explained with reference to the following non-limiting example.

[0104] A reactor according to the invention was manufactured in which the welded reactor plate stack had a segment width of 530 mm, a depth of 580 mm for a total of three segments, and a stack height including end plates of 277 mm before separation of the segments. The end plates (3) were 50 mm thick. Four reactor modules are integrated into each segment, which have a heat transfer area in the milled final state of 70 mm wide and 120 mm long. The length of the four recesses (5) per segment was 72 mm each, resulting in a recess-to-width ratio of a segment, taking into account the punched out portions (4) at the edge of the plates, of approximately 60%. The width of the recesses was 5 mm. The plate arrangement was regular so that the upper and lower end plates could be optionally combined for welding using the electron beam welding process.Three inlet openings (8) with a diameter of 11.3 mm each were machined into each of the two end plates per segment, located 5.3 mm from the plate stack. From there, the cooling water flow was distributed into coolant channels perpendicular to the plate plane (11a) with a diameter of 9 mm. The coolant channels in the plate plane (Hb) were 3 mm wide and 3 mm deep. The cooling channels running parallel to the reaction channels were 1.5 mm wide and 0.5 mm deep. The reaction channels were 4 x 4 mm. The prefabricated holes for heating elements (heating cartridges) (7) were 6 mm in diameter and were drilled out to a diameter of 10 mm. After diffusion bonding, the height of the plate stack was only approximately 270 mm. Thus, after arranging the segments in the rotated state, the total height of the finished reactor (three times the segment 6') was 810 mm, with a known segment width of 530 mm.When reassembled after rearranging the segments, the distance between the front and rear of the segments was approximately 193 mm (depth of the segments 6). Thus, the ratio of stack height to segment depth in the finished reactor was approximately 5.2. The reactor was finally milled completely on both sides, so that the maximum depth of the finished reactor was 170 mm. To open the reaction channels, an additional 25 mm was milled off on each side, resulting in a total length of the reaction channels of 120 mm. The surrounding edge was used for stud bolts that fix a continuous flange. The reactor was filled with nickel catalyst with a grain size of 300-400 pm in diameter and used for methanation while cooling with demineralized water.

Claims

Claims 1. A method for producing reactors, preferably (micro-)structured reactors, comprising levels for, on the one hand, the flow of reaction medium and, on the other hand, the flow of heat transfer medium, in which a) structured metal plates, each having the same width and the same depth for the respective levels, are stacked on top of one another; a1) optionally one or two structured or non-structured end metal plates are stacked as the top and / or bottom end plate; b) the plates stacked in this way are joined to one another by means of diffusion welding; c) the diffusion-bonded stack thus obtained is divided in the width direction into individual segments, each having the same depth; d) a desired number of individual segments obtained in step c) are arranged on top of one another and / or next to one another and joined to one another.

2. Method according to claim 1, characterized in that before step c) or simultaneously with step c), recesses are machined into the metal plates or the stack, along which the division then takes place in step c).

3. Method according to claim 1 or 2, characterized in that one or more recesses are incorporated into the metal plates or the stack, wherein the ratio of the sum of the recess lengths to the total width of the metal plates is preferably from 60% to 90%.

4. Method according to one of the preceding claims, in particular claim 1, characterized in that a ratio of segment depth to recess length of 2 to 8 is maintained.

5. Method according to one of the preceding claims, in particular claim 1, characterized in that the metal plates used in step a) have an approximately square shape.

6. Method according to one of the preceding claims, in particular claim 1, characterized in that the connection points of the individual segments obtained in step d) are planarized with one another to produce flat sealing edges, in the case of circumferential welding in step d) preferably by milling the resulting weld seams.

7. Method according to claim 7, characterized in that the flat sealing edges are adapted with a flange.

8. Method according to one of the preceding claims, in particular claim 1, characterized in that the metal plates are selected and structured so that the cooling medium in the resulting reactor can flow at least partially in cross-flow transversely to the flow direction of the process fluid and preferably at least a double deflection of the cooling medium can take place within the distribution channels.

9. Process according to one of the preceding claims, in particular claim 1, characterized in that the metal plates are selected and structured so that the cooling medium in the resulting reactor can flow in cross-flow through regions without proximity to reaction channels.

10. Method according to one of the preceding claims, in particular claim 1, characterized in that the structured or non-structured end metal plates, if present, have a thickness of equal to or more than 10 mm and, preferably on the sides, inlet openings for cooling medium.

11. Method according to one of the preceding claims, in particular claim 1, characterized in that after step c) or after step d), preferably after step d) f) the front and rear sides of the segments are milled down to the openings of the reaction channels. Reactor manufactured according to one of claims 1 to 11, characterized in that it has a desired number of individual segments arranged one on top of the other and / or next to each other and connected to each other, made of diffusion-welded stacks of microstructured metal plates, and the distribution channels for the cooling medium are deflected at least twice, and wherein - the cooling medium is first directed laterally in cross-flow exclusively in Regions resulting from the end metal plates of the stacks are introduced transversely to the flow direction of the process fluid, after which the cooling medium is redirected in the stack direction and distributed among several reaction regions within a segment. Use of a reactor according to claim 12 or a reactor produced by a process according to any one of claims 1 to 11, in particular claim 1, for Fischer-Tropsch reactions or methanation reactions.

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