Fixed-bed tubular reactor

Abstract

The present invention relates to a tubular reactor (1) comprising a catalyst powder bed confined within an annular space (30) bounded by an inner wall and an outer wall (15), The insert (20) comprises a distribution chamber (40) and a collection chamber (50) separated by at least one first partition wall portion (60), the distribution chamber (40) comprising distribution compartments separated from each other by second partition wall portions, each distribution compartment and collection chamber (50) comprising an inlet opening and an outlet opening (51), respectively; The inner wall includes distribution openings (43a, 43b, 43c, 43d, and 43e) and collection openings (53), each of which allows distribution of gas towards the annular space (30) and collection openings (53) which allow collection of the gas distributed into the annular space (30) by the collection chamber (50).

Description

Technical Field

[0001] The present invention relates to the field of exchanger reactors. Specifically, the present invention relates to the field of catalytic exchanger reactors that implement solid catalysts, particularly in the form of powders.

[0002] In this regard, the present invention provides a catalytic exchanger reactor that can implement an exothermic organic synthesis process. In particular, these organic compounds can include synthetic fuels and combustibles.

Background Art

[0003] Catalytic reactors using solid catalysts are widely implemented for the synthesis of organic compounds such as synthetic fuels or combustibles, among which natural gas substitutes, dimethyl ether, or methanol may be mentioned.

[0004] In particular, these compounds are obtained by the reaction of hydrogen and carbon monoxide in the presence of a suitable solid catalyst.

[0005] However, the chemical reactions related to the synthesis of these compounds are highly exothermic and release a large amount of heat that can degrade the solid catalyst. In particular, this degradation of the solid catalyst is reflected by the deactivation of the solid catalyst, leading to a reduction in the degree of conversion of the existing chemical species. Also, the selectivity of the reactions involved is affected.

[0006] In practice, these reactions can be implemented in a shell-and-tube type reactor-exchanger, which includes reaction channels that are provided with a solid catalyst and are continuously cooled by a heat transfer fluid. In this reactor type, the reactive gas circulates axially through tubes containing the catalyst (for example, in the form of powder).

[0007] Nevertheless, despite the implementation of cooling by heat transfer fluid, this reactor type remains sensitive to the heat released by the reactions occurring within the reactor.

[0008] In particular, hot spots (generally observed near the reactive gas inlet) degrade the solid catalyst and, consequently, reduce the performance of the reactor-exchanger.

[0009] Next, to overcome these problems, an arrangement has been proposed that allows for the distribution of reagents to be divided over the entire length of the tube. This solution then allows for better temperature uniformity to be obtained over the entire length of the reactor.

[0010] In this regard, Patent Documents 1, 2, 3, 4, and 5 propose reactor-exchangers that implement the distribution of reagents from an annular distribution space. In particular, these reactor-exchangers (generally having a cylindrical shape) include a tube, an annular distribution space, a catalyst charge, and a collection space, which are arranged coaxially and starting from the outside of the reactor.

[0011] However, this arrangement is not satisfactory.

[0012] In fact, the presence of an annular distribution space arranged around the catalyst charge limits heat transfer from the catalyst to the tube, rendering commonly considered cooling systems ineffective. Nevertheless, it remains possible to insert a heat-conducting element into the reactor. However, such a solution remains unsuitable for reactors containing tubes with small diameters.

[0013] Conversely, Patent Document 6 proposes implementing an insert, which provides a distribution chamber and a collection chamber, positioned in the center of the tube, and together with the tube, defines an annular space for housing a solid catalyst.

[0014] However, the configuration proposed in this document does not allow for uniform distribution of the reagent within the cyclic space. More specifically, this configuration does not allow for obtaining the optimal temperature profile within the solid catalyst.

[0015] Figure 1 of Patent Document 7 illustrates another example of a shell-tube type reactor. In particular, this reactor is provided with an injection tube, which is immersed in a catalyst powder bed, and holes are formed along the injection tube. Specifically, these are arranged to ensure the injection of reactive gas at different levels of the catalyst powder bed and thus to limit the appearance of hot spots in the bed.

[0016] However, this reactor is not satisfactory.

[0017] In fact, to ensure its cooling, this reactor requires the setup of multiple circulation circuits for the heat transfer fluid, which increases its complexity accordingly.

[0018] Patent document 8 (in particular, Figure 3a) discloses another example of a reactor arranged to allow the stepwise injection of reagent C for its reaction with reagent A. In this regard, the reactor comprises two layers (or channels), separated by a wall, and intended to ensure the circulation of reagent A and reagent C, respectively. Furthermore, the two layers are fluidly connected by a plurality of pores formed in the wall separating them. In particular, these pores are arranged to ensure the gradual mixing of reagent C and reagent A. Thus, this gradual mixing makes it possible to limit the appearance of hot spots. However, the arrangement of the reactor in the form of a stack of layers makes it almost impossible to make it compact. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] U.S. Patent No. 3,758,279 [Patent Document 2] U.S. Patent No. 4,374,094 [Patent Document 3] EP0560157 [Patent Document 4] IT8021172 [Patent Document 5] U.S. Patent No. 2,997,374 [Patent Document 6] CN103990420 [Patent Document 7] U.S. Patent No. 8,961,909 [Patent Document 8] U.S. Patent No. 7,402,719 [Summary of the Invention] [Problems to be Solved by the Invention]

[0020] An object of the present invention is to provide a fixed-bed tubular reactor that enables more uniform distribution of reagents in a solid catalyst.

[0021] Another object of the present invention is to provide a fixed-bed tubular reactor that enables more uniform distribution of the heat flow generated in a solid catalyst.

[0022] Another object of the present invention is to provide a fixed-bed tubular reactor that enables better cooling management.

[0023] Another object of the present invention is to provide a fixed-bed tubular reactor with improved reliability and service life compared to reactors known from the prior art.

[0024] Another object of the present invention is to provide a fixed-bed tubular reactor that enables optimization (increase) of the gas passage time in a fixed catalyst powder bed.

[0025] An object of the present invention is to provide a fixed-bed tubular reactor that enables stepwise injection of one or more reagents in a solid catalyst. [Means for solving the problem]

[0026] The object of the present invention is at least partially realized by a fixed-bed tubular reactor extending between a first end and a second end along a longitudinal axis XX', the reactor comprising a catalyst powder bed confined within an annular space defined by the outer wall of a hollow tube and the inner wall of a hollow insert coaxially disposed within the hollow tube, The hollow insert includes at least one distribution chamber and at least one collection chamber separated from each other by at least one first partition wall, the at least one distribution chamber includes a plurality of distribution compartments separated from each other by one or more second partition walls, each distribution compartment and at least one collection chamber includes a gas intake opening at a first end and a gas discharge opening at a second end, respectively. The outer wall portion includes a distribution opening and at least one collection opening extending over a length L, each distribution opening enabling the distribution of gas that can be introduced into the annular space through an intake opening into the distribution compartment, and the collection opening enabling the collection of the gas distributed into the annular space by a collection chamber.

[0027] Each distribution opening and / or each collection opening may be formed by a single opening.

[0028] Alternatively, the distribution opening and / or collection opening may include multiple openings, which are aligned, for example, according to their direction of extension.

[0029] In one implementation configuration, the reactor includes a distribution space and a collection space at a first end and a second end, respectively, and a hollow insert is disposed between the distribution space and the collection space.

[0030] In one implementation, the distribution compartment is sealed at a second end, and at least one collection chamber is sealed at a first end.

[0031] In one implementation, each distribution compartment is separated from the distribution space by a wall called an intake wall, and the intake opening is formed within the intake wall.

[0032] In one implementation, each intake opening is shaped to reduce the pressure of a gas that can be introduced into its associated distribution compartment at a given flow rate.

[0033] In one implementation, the pressure drop provided by the intake opening is regulated according to a distance called the reaction distance, which is measured in an annular space between the distribution opening of the distribution compartment under consideration and the collection opening closest to the distribution opening.

[0034] In one implementation, the pressure drop brought about by the intake opening increases further as the reaction distance decreases.

[0035] In one implementation, the pressure drop associated with a given intake opening is adjusted by the size of the intake opening.

[0036] In one implementation configuration, the porous element is housed within the intake opening, and the porous element has a degree of porosity that allows for a pressure drop.

[0037] In one implementation, the porous element may include at least one material selected from fibrous materials, particularly wool, braids, or metal or ceramic fabrics.

[0038] In one implementation configuration, the distribution space includes a volumetric section, the intake opening opens into the volumetric section, and the volumetric section is connected to a gas supply duct.

[0039] In one implementation, the distribution space includes volumetric subsections, and at least one intake opening opens into each of the volumetric subsections.

[0040] In one implementation, the volumetric subsection forms an annular intake space, which is arranged concentrically and separated by a tight annular wall.

[0041] In one implementation configuration, several intake openings open into at least one of the volumetric subsections.

[0042] In one implementation configuration, each volumetric subsection is connected to a different gas intake duct.

[0043] In one implementation, the reactor is provided with a porous film that covers the inner wall and is arranged to prevent the passage of powder from the catalyst powder bed through a distribution opening or a collection opening.

[0044] In one implementation configuration, the catalyst powder is held within the annular space at each end of the annular space by seals made of fibrous material, which are advantageously held in a compressed state relative to the catalyst powder by springs, the springs in contact with mechanically linked retaining plates of the tube.

[0045] According to one implementation configuration, the second wall portion does not have openings above the first and second sections extending from the first and second ends, respectively, and the first and second sections overlap the powder bed over a height H1, the height H1 being between 0.2 and 10 times the distance D1, and advantageously between 1 and 2 times, the distance D1 separating the distribution opening from the immediately adjacent collection opening, and is measured along the outer surface of the outer wall portion.

[0046] According to one implementation configuration, the hollow insert is provided with a centering means that holds the hollow insert in a position coaxial with the hollow tube, and advantageously, the centering means includes a boss formed on a second wall portion.

[0047] According to one implementation configuration, the collection opening and distribution opening have widths that are between 1 / 100 and 1 / 2 of the diameter of the hollow tube, preferably between 1 / 20 and 1 / 4.

[0048] In one implementation configuration, the hollow insert forms a single-piece component.

[0049] Other features and advantages will become apparent in the following description of a fixed-bed tubular reactor according to the present invention, which is given as a non-limiting example with reference to the attached drawings. [Brief explanation of the drawing]

[0050] [Figure 1] This is a schematic representation of a fixed-bed tubular reactor according to the present invention, and in particular, it is a diagram showing the reactor according to a longitudinal cross-sectional plane passing through the longitudinal axis XX' of the reactor. [Figure 2]This diagram shows a cross-sectional view of the tubular reactor in Figure 1, with a transverse plane perpendicular to the longitudinal axis XX'. The tubular reactor includes two distribution chambers and two collection chambers, each distribution chamber being divided into five distribution compartments arranged symmetrically with respect to the bisecting plane P. The arrows indicate the direction of gas circulation in the annular space. [Figure 3] Figure 1 is a cross-sectional view of the tubular reactor, taken from a cross-sectional plane perpendicular to the longitudinal axis XX', illustrating the intake openings with different cross-sections. [Figure 4] Figure 1 is a cross-sectional view of the tubular reactor, taken from a cross-sectional plane perpendicular to the longitudinal axis XX', and illustrates the suction opening where the porous element is housed. [Figure 5] This is a diagram illustrating a hollow insert according to the present invention, which has a boss for centering the hollow insert inside a hollow tube. [Figure 6] This is a diagram illustrating a filter element (particularly a filter element formed by four fiber planes) that can be implemented in a tubular reactor according to the present invention. [Figure 7] This is a schematic representation of a fixed-bed tubular reactor according to another example of the present invention, and in particular, it is a diagram showing the reactor according to a longitudinal cross-sectional plane passing through the longitudinal axis XX' of the reactor. [Figure 8] This is a diagram showing a representation of a second modification of the present invention, following a longitudinal cross-sectional plane passing through the longitudinal axis XX' of the distribution space. [Figure 9A] This diagram follows the cross-sectional plane AA of Figure 8. [Figure 9B] This diagram follows the cross-sectional plane BB of Figure 8. [Figure 9C] This diagram follows the cross-sectional plane CC shown in Figure 8. [Figure 10] This is a partial schematic representation (at the first end) of an arrangement comprising multiple tubular reactors according to the present invention. [Modes for carrying out the invention]

[0051] The present invention relates to a tubular reactor-exchanger equipped with a fixed catalyst powder bed. In particular, the catalyst powder bed is confined within an annular space defined by the wall of a hollow tube (referred to as the outer wall) and another wall of a hollow insert coaxially housed within the tube (referred to as the inner wall).

[0052] According to the present invention, the hollow insert includes at least one distribution chamber and at least one collection chamber separated from each other by at least one first partition wall. Furthermore, the at least one distribution chamber includes a plurality of distribution compartments separated from each other by one or more second partition walls. Each distribution compartment and at least one collection chamber includes a gas intake opening at a first end and a gas discharge opening at a second end, respectively.

[0053] The presence of a gas intake opening at the first end should be understood to imply that the opening is positioned to allow gas introduction through the first end. In other words, the gas intake opening may be located at the first end.

[0054] Similarly, the presence of a gas discharge opening at the second end implies that the opening is positioned to allow gas discharge through the second end. In other words, the gas discharge opening may be located at the second end.

[0055] The inner wall includes distribution openings and at least one collection opening, which extend over a length L. Each distribution opening allows for the distribution of gas that can be introduced into the annular space through an intake opening into the distribution compartment, and the collection opening allows for the collection of the gas distributed into the annular space by a collection chamber.

[0056] The implementation of multiple distribution compartments allows for the division of the distribution of reactive gases from the same distribution chamber to different locations on the catalyst powder bed. Therefore, this mode of distribution limits the appearance of hot spots and preserves the performance of the catalyst powder bed.

[0057] Similarly, the multiplicity of the distribution compartments allows for the consideration of the distribution of gases or mixtures of gases of different properties within the annular space. This last aspect allows for the control of the reactions involved in the powder bed (in particular, their selectivity).

[0058] The advantages associated with different aspects of the present invention will become clearer when you read the detailed description below.

[0059] Therefore, Figures 1 and 2 show embodiments of a fixed-bed tubular reactor according to the present invention.

[0060] The tubular reactor 1 according to the present invention includes a hollow tube 10, which extends between a first end 11 and a second end 12 along a longitudinal axis XX'. The hollow tube 10 can have axial symmetry about the longitudinal axis XX'. It should be understood that the longitudinal axis XX' can be the axis of rotation of the hollow tube 10.

[0061] The hollow tube 10 may contain metal, and in particular, it may contain a metal selected from among steel, aluminum, copper, and nickel alloys.

[0062] The diameter of the inner surface of the hollow tube can range from 5 mm to 100 mm.

[0063] The wall portion (referred to as the outer wall portion 15) that forms the hollow tube 10 can have a thickness ranging from 0.5 mm to 10 mm.

[0064] The hollow tube 10 can have a length that falls between 10 and 200 times the diameter of its inner surface.

[0065] Furthermore, the tubular reactor 1 includes a hollow insert 20, which also extends along the longitudinal axis XX' and has a generally cylindrical shape.

[0066] In particular, the hollow insert 20 is housed coaxially with the hollow tube within the volume V of the hollow tube. Specifically, the insert 20 also includes a wall portion called the inner wall portion 21, which, together with the outer wall portion 15, defines the boundary of the annular space 30.

[0067] In this respect, the annular space 30 is filled with catalyst powder and is the site of the reaction for the conversion of reactive gases that are likely to pass through the tubular reactor 1.

[0068] The annular space 30 can have a thickness (defined as the distance between the outer wall portion 15 and the inner wall portion 21) that falls between 2% and 20% of the diameter of the inner surface of the hollow tube 10.

[0069] The hollow insert 20 can be a single-piece part.

[0070] In a particularly advantageous configuration, the hollow insert 20 may include a centering means that holds the hollow insert 20 in a position coaxial with the hollow tube. For example, as shown in Figure 5, the centering means includes a boss 22 formed on the inner wall.

[0071] In particular, these centering means make it possible to consider hollow inserts having a length at least 20 times greater than the diameter of the insert.

[0072] Furthermore, these measures also facilitate the installation of the tubular reactor 1.

[0073] Furthermore, the hollow insert 20 includes at least one distribution chamber 40 and at least one collection chamber 50. In particular, the hollow insert 20 may include between one and four distribution chambers 40 and between one and four collection chambers 50.

[0074] Advantageously, at least one distribution chamber 40 and at least one collection chamber 50 are arranged alternately and extend along the entire length of the hollow insert 20. Furthermore, at least one collection chamber 50 and at least one distribution chamber 40 are separated from each other by a first partition wall 60. Thus, it should be understood that the distribution chamber 40 is bounded by two partition wall sections 60 and sections of the inner wall 21.

[0075] Similarly, the collection chamber 50 is also bounded by two first partition wall sections 60 and another section of the inner wall section 21.

[0076] Furthermore, the first partition wall 60 extends over the entire length of the hollow insert within the volume defined by the hollow insert 20, and is positioned to prevent the direct passage of gas from one chamber to another.

[0077] For example, the first partition wall 60 forms a plane passing through the longitudinal axis XX'. In particular, the two first partition wall 60 of the distribution chamber 40 can generally have an elongated shape and can extend along the longitudinal axis XX' from the first end 11 to the second end 12. In particular, the two first partition wall 60 of the distribution chamber 40 can have a common side that coincides with the longitudinal axis XX'. Furthermore, it should be understood that the two first wall 60 of the distribution chamber 40 can be coplanar, especially when the hollow insert 20 contains only the distribution chamber 40.

[0078] Furthermore, each distribution chamber 40 includes a plurality of distribution compartments 40a, 40b, 40c, 40d, and 40e, which are separated from each other by one or more second partition walls 41a, 41b, 41c, and 41d, and the one or more second partition walls 41a, 41b, 41c, and 41d are arranged to prevent a direct passage of gas from one compartment to another.

[0079] Advantageously, the second partition walls 41a, 41b, 41c, and 41d can be parallel to each other, and more specifically, they can be parallel to the bisecting plane P of the first wall 60 that defines the boundary of the distribution chamber 40.

[0080] In this configuration, the distribution compartments 40a, 40b, 40c, 40d, and 40e extend from the first end 11 to the second end 12.

[0081] More specifically, and still according to this configuration, the distribution compartments 40a, 40b, 40c, 40d, and 40e form a symmetrical arrangement with respect to the bisecting plane P.

[0082] Each of the distribution compartments 40a, 40b, 40c, 40d, and 40e includes gas intake openings 42a, 42b, 42c, 42d, and 42e at the first end 11 of the insert 20 (Figures 1 and 3), through which one or more reactive gases can be introduced.

[0083] Similarly, at least one collection chamber 50 includes a discharge opening 51 at the second end 12 of the hollow insert 20, and one or more gases can be discharged through the discharge opening 51 (Figure 1).

[0084] Furthermore, the distribution chambers 40a, 40b, 40c, 40d, and 40e are sealed at the second end 12, and at least one collection chamber 50 is sealed at the first end 11.

[0085] Furthermore, the hollow insert 20 is provided with a plurality of distribution openings 43a, 43b, 43c, 43d, and 43e, which extend continuously (or not continuously) over a length L and, advantageously, parallel to the longitudinal axis XX'.

[0086] Each distribution opening may be formed by a single opening.

[0087] Alternatively, the distribution opening may include multiple openings, which are aligned, for example, according to their direction of extension.

[0088] In particular, each of these distribution openings 43a, 43b, 43c, 43d, and 43e forms one or more passages within the inner wall 21 and is associated with different distribution compartments 40a, 40b, 40c, 40d, and 40e. Specifically, each distribution opening 43a, 43b, 43c, 43d, and 43e is arranged to allow the distribution of gas in the annular space 30 that can be introduced into the associated distribution compartments 40a, 40b, 40c, 40d, and 40e through the intake openings 42a, 42b, 42c, 42d, and 42e.

[0089] Furthermore, the hollow insert 20 includes at least one collection opening 53, the at least one collection opening 53 extending over a length L and, advantageously, parallel to the longitudinal axis XX'. In particular, the at least one collection opening 53 forms a passage within the inner wall portion 21 and is associated with at least one collection chamber 50. Specifically, the at least one collection opening 53 is positioned to allow collection (by the collection chamber 50) of gas distributed into the annular space 30.

[0090] Each collection opening may be formed by a single opening.

[0091] Alternatively, the collection opening may include multiple openings, which are aligned, for example, according to their direction of extension.

[0092] Therefore, the distribution openings 43a, 43b, 43c, 43d, and 43e of the distribution compartments 40a, 40b, 40c, 40d, and 40e allow for the distribution of gas that can be introduced into the compartment toward the annular space 30 through the intake openings 42a, 42b, 42c, 42d, and 42e.

[0093] Similarly, the collection opening 53 allows the collection of gas distributed into the annular space 30 by the collection chamber 50.

[0094] Therefore, the multiplicity of the distribution openings associated with a given distribution chamber allows for the injection of one or more reactive gases into the annular space 30 in different areas of the space 30. This distribution of gas injection areas makes it possible to replicate the principle of stepwise injection and thus limit the appearance of localized heat-up (hot spots) in the annular area 30. Furthermore, this limiting of heat-up prevents the phenomenon of sintering of the catalyst powder present in the annular space.

[0095] Considering multiple distribution openings 40a, 40b, 40c, 40d, and 40e for each distribution chamber 40 makes it possible to consider a hollow insert 20 limited to one single (and possibly two) distribution chambers. Moreover, such an arrangement makes it possible to simplify the manufacturing of the hollow insert 20.

[0096] Furthermore, the extension of the distribution openings 43a, 43b, 43c, 43d, and 43e over a length L allows for wider injection of gas into the annular space 30, and thus makes it possible to limit the appearance of hot spots.

[0097] Advantageously, the collection openings 43a, 43b, 43c, 43d, and 43e may have a width that is between 1 / 100 and 1 / 2 of the diameter of the hollow tube 10, and advantageously, a width that is between 1 / 20 and 1 / 4.

[0098] Advantageously, the distribution openings 43a, 43b, 43c, 43d, and 43e of a given distribution chamber 40 can be arranged symmetrically with respect to the bisecting plane P of the wall portion 60 that defines the boundary of the chamber (Figure 2).

[0099] Therefore, during the operation of the tubular reactor 1, gas is introduced through the intake openings 42a, 42b, 42c, 42d, and 42e in the distribution compartments 40a, 40b, 40c, 40d, and 40e, respectively. This gas is then distributed into the annular space 30 through the distribution openings 43a, 43b, 43c, 43d, and 43e, respectively, and then collected through the collection opening 53.

[0100] The gas pathway within the annular space 30 depends on the relative positioning of the intake openings 42a, 42b, 42c, 42d, and 42e and the collection opening 53. In particular, and as illustrated by the arrows in Figure 2, the gas distributed through a given distribution opening is primarily collected through the collection opening 53 closest to the distribution opening. The "collection opening closest to the distribution opening" should be understood as the collection opening associated with the shortest reaction pathway of the gas compared to other collection openings. In other words, the collection opening closest to the distribution opening is none other than the first collection opening the gas encounters during its circulation within the annular space 30.

[0101] The tubular reactor 1 may include a distribution space 13 and a collection space 14 at the first end 11 and the second end 12, respectively, with a hollow insert 20 disposed between them (Figure 1).

[0102] In this regard, each distribution compartment 40a, 40b, 40c, 40d, and 40e is separated from the distribution space 13 by a wall called an intake wall 44, and the intake openings 42a, 42b, 42c, 42d, and 42e are formed within the intake wall 44 (Figure 3).

[0103] According to an advantageous embodiment, each intake opening 42a, 42b, 42c, 42d, and 42e is shaped to pressure-down a gas that can be introduced into the distribution compartments 40a, 40b, 40c, 40d, and 40e, which depends on the distance (referred to as the reaction distance) that is actually covered by the gas in the annular space 30.

[0104] In this regard, the reaction distance depends on the compartment under consideration, and in particular on the distance between the collection opening of the compartment and the nearest collection opening 52. Specifically, the intake openings 42a, 42b, 42c, 42d, and 42e of a given distribution compartment 40a, 40b, 40c, 40d, and 40e can be shaped to produce a pressure drop that is even higher the shorter the distance between the distribution opening of the compartment and the nearest collection opening.

[0105] Advantageously, and as illustrated in Figure 3, the pressure drop associated with a given intake opening is regulated by its cross-section. More specifically, the pressure drop provided by the intake opening increases as its cross-section decreases (according to the present invention, the cross-section of the opening is nothing other than the surface or extent of the opening).

[0106] Alternatively or complementary, and as illustrated in Figure 5, the pressure drop at one of the intake openings 42a, 42b, 42c, 42d, and 42e can be provided by porous elements 44 housed within the intake openings 42a, 42b, 42c, 42d, and 42e. In particular, each porous element 44 has a degree of porosity that allows it to produce a predetermined pressure drop for a given gas flow rate.

[0107] In this regard, the porous element may include at least one of fibrous materials, particularly wool, braids, or materials selected from metal fabrics or ceramic fabrics.

[0108] Considering the pressure drop adjusted according to the reaction distance allows for better segmentation and control of the gas flow in the annular space. This consideration leads to better optimization of the localized heating phenomenon of the catalyst powder bed, resulting in an improvement in the performance of the bed.

[0109] However, the present invention is not limited to regulating the pressure drop brought about at the intake opening. In fact, based on the above factors, those skilled in the art may also consider, alternatively or complementaryly, bringing about a pressure drop at the distribution opening.

[0110] Advantageously, the tubular reactor 1 includes a filter positioned to prevent the catalyst powder from passing into the distribution compartment or collection chamber.

[0111] For example, as shown in Figure 2, the filter 70 may be arranged so as to overlap the inner wall portion 21.

[0112] Alternatively, the filter may include a filter element 71 housed within a distribution opening and a collection opening. The filter element 71 may include multiple planes 71a, 71b, 71c, and 71d containing fibers. An example illustrated in Figure 6 includes, in particular, four planes, each with rectangular or circular fibers, tilted at + / -45° with respect to the longitudinal axis XX'. More specifically, the fibers of two consecutive planes are oriented according to two different angles, in particular perpendicular from one plane to the other.

[0113] According to a particularly advantageous embodiment illustrated in Figure 7, the catalyst powder is retained within the annular space 30 at each end of the annular space 30 by seals 31 (for example, made from a fibrous material).

[0114] Insofar as the seal is made from a fibrous material, the fibrous material is necessarily porous and therefore permeable to reactive gases.

[0115] In this regard, the fibrous material may include at least one element selected from glass fibers, ceramic fibers, metal fibers, carbon fibers, and polymer material fibers.

[0116] In particular, the seal 31 can be in the form of a braid, sheath, or cord, or it can simply include a fibrous material filling.

[0117] Advantageously, the fibrous material is a thermal insulator and has a thermal conductivity substantially equivalent to that of the catalyst used (0.2 W / m / K to 10 W / m / K).

[0118] According to an advantageous embodiment, a seal 31 made of a fibrous material is held in a compressed state relative to the catalyst powder by a spring 32. For example, the spring 32 abuts against a retaining plate 33 which is mechanically linked to the tube by a ring 34.

[0119] The seal 31, made from a fibrous material, combined with a spring, allows for better compaction of the catalyst powder and prevents loss of the catalyst powder during reactor handling or transport.

[0120] As long as the seal 31 is porous, the reactive gas can enter the annular space directly without passing through the distribution compartment.

[0121] In this case (Figure 7), it is particularly advantageous to provide an arrangement of the hollow insert 20 that allows the reactive gas to be given a predetermined path in an annular space in order to promote its conversion in contact with the catalyst powder bed. This predetermined path has a length that is between 0.2 and 10 times, preferably between 1 and 2 times, that of the previously defined reaction path.

[0122] For this purpose, the inner wall portion 21 may lack openings across the first section 21a and the second section extending from the first end 11 and the second end 12, respectively.

[0123] In this regard, the first section 21a and the second section overlap the powder bed over a height H1. The height H1 is between 0.5 and 10 times the reaction distance, and advantageously between 1 and 2 times.

[0124] As mentioned above, the introduction of gas is carried out in the distribution space. In this regard, according to the first modification, the distribution space may be arranged to allow the introduction of the same gas into each of the distribution compartments, or according to the second modification, it may be arranged to allow the introduction of different gases into each compartment.

[0125] According to the first modification (Figure 1), the distribution space 13 includes a volumetric section, and all intake openings open into the volumetric section. According to this first modification, the volumetric section is connected to a gas supply duct. In other words, all distribution compartments 40a, 40b, 40c, 40d, and 40e are supplied with the same gas or gas mixture.

[0126] According to a second modification illustrated in Figures 8, 9A, 9B, and 9C, the distribution space 13 includes volumetric subsections 45a, 45b, and 45c, with at least one intake opening 42a, 42b, 42c, 42d, and 42e opening into each of the volumetric subsections 45a, 45b, and 45c. Advantageously, the volumetric subsections 45a, 45b, and 45c form an annular intake space, which is concentrically arranged and separated by tight annular walls 46a, 46b (Figures 9A and 9B). Advantageously, several intake openings 42a, 42b, 42c, 42d, and 42e are capable of opening into at least one of the volumetric subsections. For example, the intake openings 42a, 42b, 42c, 42d, and 42e associated with distribution compartments 40a, 40b, 40c, 40d, and 40e that give the same reaction distance to the gas can open into the same volumetric subsection. In particular, as shown in Figure 9B, the intake openings 42a and 42e open into volumetric subsection 45a, the intake openings 42b and 42d open into volumetric subsection 45b, and the intake opening 42c opens into volumetric subsection 45c.

[0127] Advantageously, each of the volumetric subsections 45a, 45b, and 45c can be connected to a different gas intake duct. In particular, volumetric subsections 45a, 45b, and 45c are connected to a first duct 47a, a second duct 47b, and a third duct 47c, respectively (Figure 8).

[0128] Therefore, according to this second modification, it is possible to consider injecting different gases or different gas mixtures into the distribution compartment.

[0129] Figure 10 is an explanatory diagram of an implementation of a plurality of tubular reactors 1 according to the present invention, in particular by a second modification (nevertheless, it should be understood that a first modification may also be considered). In particular, this implementation includes three tubular reactors 1 arranged parallel to each other within a single shell. Specifically, the tubular retaining plate 80 allows for the holding of the tubular reactors and allows for the formation of space for the circulation of a heat transfer fluid intended to cool the tubular reactors 1.

[0130] Furthermore, all tubular reactors can be supplied with gas through the same supply ducts: supply ducts 47a, 47b, and 47c.

[0131] In particular, and as shown in Figure 10, duct 47a is connected to each volume subsection 45a of reactor 1, duct 47b is connected to each volume subsection 45b of reactor 1, and duct 47c is connected to each volume subsection 45c of reactor 1.

[0132] The tubular reactor according to the present invention, in particular the implementation of compartments within a distribution chamber, allows for the consideration of stepwise distribution of gases and gas mixtures in an annular space.

[0133] Therefore, this configuration actively addresses the problem of catalyst powder overheating and thus limits the appearance of hot spots. This results in a more effective and durable device.

[0134] Furthermore, the arrangement of the catalyst powder within the annular space promotes the cooling of the catalyst powder.

[0135] Advantageously, the tubular reactor according to the present invention is implemented for the synthesis of methane, methanol, and dimethyl ether, or for implementing the Fisher-Tropsch synthesis method.

[0136] Hollow inserts can be manufactured in the form of one-piece parts according to additive manufacturing processes (e.g., 3D manufacturing processes). These manufacturing processes pave the way for the formation of parts with complex shapes, in particular, the formation of one-piece parts that include distribution spaces, collection spaces, and hollow inserts.

[0137] Alternatively, the hollow insert can be a separate element assembled together with a distribution space (formed by the first end body) and a collection space (formed by the second end body).

[0138] Assembly may include the installation of seals spaced between each end piece and the hollow insert. [Explanation of Symbols]

[0139] 1. Tubular reactor 10 hollow tube 11 First end 12 Second end 13 Distribution space 14 Collection Space 15 Outer wall 20 hollow inserts 21 Inner wall 21a Section 1 22 Boss 30 Circular Space 31 stickers 32 Springs 33 Retaining Plates 34 rings 40 distribution chambers 40a, 40b, 40c, 40d, 40e Distribution compartments 41a, 41b, 41c, 41d Second partition wall section 42a, 42b, 42c, 42d, 42e Gas intake opening 43a, 43b, 43c, 43d, 43e distribution openings 44 Intake wall section 45a, 45b, 45c Volume subsections 46a, 46b wall 47a First duct 47b Second duct 47c Third duct 50 Collection Chambers 51 Discharge opening 52 Collection opening 53 Collection opening 60 First partition wall section 70 filters 71 filter elements 71a, 71b, 71c, 71d plane 80 Tubular retaining plate H1 Height L Length P bisector plane V Volume of a hollow tube XX' Longitudinal axis

Claims

1. A fixed-bed tubular reactor (1) extending between a first end (11) and a second end (12) along a longitudinal axis XX', comprising a catalyst powder bed confined within an annular space (30) whose boundary is defined by the inner wall portion (15) of a hollow tube (10) and the outer wall portion (21) of a hollow insert (20) coaxially disposed within the hollow tube (10), The hollow insert (20) includes at least one distribution chamber (40) and at least one collection chamber (50) separated from each other by at least one first partition wall (60), the at least one distribution chamber (40) includes a plurality of distribution compartments (40a, 40b, 40c, 40d, and 40e) separated from each other by one or more second partition walls (41a, 41b, 41c, and 41d), each distribution compartment (40a, 40b, 40c, 40d, and 40e) and the at least one collection chamber (50) include gas intake openings (42a, 42b, 42c, 42d, and 42e) at the first end (11) and a gas discharge opening (51) at the second end (12), A fixed-bed tubular reactor (1), wherein the inner wall portion (21) includes distribution openings (43a, 43b, 43c, 43d, and 43e) and at least one collection opening (53) extending parallel to the longitudinal axis XX', each distribution opening (43a, 43b, 43c, 43d, and 43e) enabling the distribution of gas that can be introduced into the distribution compartment toward the annular space (30) through suction openings (42a, 42b, 42c, 42d, and 42e), and the collection opening (53) enabling the collection of gas distributed into the annular space (30) by the collection chamber (50).

2. The reactor according to claim 1, wherein the first end (11) and the second end (12) each include a distribution space (13) and a collection space (14), and the hollow insert (20) is disposed between the distribution space (13) and the collection space (14).

3. The reactor according to claim 2, wherein the distribution chambers (40a, 40b, 40c, 40d, and 40e) are sealed at the second end (12), and the at least one collection chamber (50) is sealed at the first end (11).

4. The reactor according to claim 2 or 3, wherein each distribution compartment is separated from the distribution space (13) by a wall called an intake wall, and the intake openings (42a, 42b, 42c, 42d, and 42e) are formed within the intake wall.

5. The reactor according to claim 4, wherein each intake opening (42a, 42b, 42c, 42d, and 42e) is shaped to reduce the pressure of the gas that can be introduced into the distribution compartment associated therewith.

6. The reactor according to claim 5, wherein the pressure drop provided by the intake openings (42a, 42b, 42c, 42d, and 42e) is regulated according to a distance called the reaction distance, the reaction distance being measured in the annular space (30) between the distribution openings (43a, 43b, 43c, 43d, and 43e) of the distribution compartment under consideration and the collection opening (53) closest to the distribution openings (43a, 43b, 43c, 43d, and 43e).

7. The reactor according to claim 6, wherein the pressure drop provided by the intake openings (42a, 42b, 42c, 42d, and 42e) increases further as the reaction distance decreases.

8. The reactor according to claim 7, wherein the pressure drop associated with a given suction opening (42a, 42b, 42c, 42d, and 42e) is adjusted by the size of the suction opening (42a, 42b, 42c, 42d, and 42e).

9. The reactor according to claim 7 or 8, wherein a porous element is housed within the intake openings (42a, 42b, 42c, 42d, and 42e), and the porous element has a degree of porosity that allows the pressure drop to occur.

10. The reactor according to claim 9, wherein the porous element may include at least one of fibrous materials, particularly wool, braids, or materials selected from metal or ceramic fabrics.

11. The reactor according to any one of claims 2 to 10, wherein the distribution space (13) includes a volumetric section, the intake opening opens into the volumetric section, and the volumetric section is connected to a gas supply duct.

12. The reactor according to any one of claims 2 to 10, wherein the distribution space (13) includes volumetric subsections (45a, 45b, and 45c), and at least one intake opening (42a, 42b, 42c, 42d, and 42e) opens into each of the volumetric subsections (45a, 45b, and 45c).

13. The reactor according to claim 12, wherein the volumetric subsections (45a, 45b, and 45c) form an annular intake space, the annular intake space is arranged concentrically and separated by tight annular walls (46a, 46b).

14. The reactor according to claim 13, wherein several suction openings open into at least one of the volumetric subsections (45a, 45b, and 45c).

15. The reactor according to claim 14, wherein each of the volumetric subsections is connected to a different gas intake duct.

16. The reactor according to any one of claims 1 to 15, wherein the reactor comprises a porous film, the porous film covering the inner wall portion (21), and is arranged to prevent the passage of powder from the catalyst powder bed through the distribution openings (43a, 43b, 43c, 43d, and 43e) and / or the collection opening (53).

17. The reactor according to any one of claims 1 to 16, wherein the catalyst powder is held in the annular space (30) at each end of the annular space (30) by a seal made of a fibrous material, and preferably the seal made of a fibrous material is held in a compressed state relative to the catalyst powder by a spring, the spring being in contact with a mechanically linked retaining plate of the tube.

18. The reactor according to any one of claims 1 to 17, wherein the inner wall portion does not have openings over the first section and the second section extending from the first end (11) and the second end (12), respectively, and the first section and the second section overlap the powder bed over a height H1.

19. The reactor according to any one of claims 1 to 18, wherein the hollow insert (20) is provided with a centering means for holding the hollow insert (20) in a position coaxial with the hollow tube (10), and advantageously the centering means includes a boss formed on the inner wall portion (21).

20. The reactor according to any one of claims 1 to 19, wherein the collection opening (53) and the distribution opening have widths that fall between 1 / 100 and 1 / 2 of the diameter of the hollow tube (10), preferably between 1 / 20 and 1 / 4.

21. The reactor according to any one of claims 1 to 20, wherein the hollow insert (20) forms a single-piece part.

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