Fixed bed tubular reactor

Abstract

Fixed-bed tubular reactor The invention relates to a tubular reactor (10), comprising: a casing (12), extending along a main axis (20); and an insert (14) arranged in said external casing, the casing (12) and the insert (14) delimiting an intermediate space (28), capable of receiving a bed (16) of catalytic powder. The insert (14) comprises a first (30, 34) and a second (32, 36) tube, extending along secondary axes; and the tubular reactor further comprises a support (15) arranged in the intermediate space (28) and fixed to each of the tubes, the support holding said tubes so that each secondary axis extends parallel to the main axis (20). Figure for abstract: Figure 1

Description

Title of the invention: Fixed bed tubular reactor

[0001] The invention relates to a tubular reactor, comprising: a casing, extending along a main axis; and an insert arranged in said external casing, the casing and the insert delimiting an intermediate space, capable of receiving a bed of catalytic powder; the insert being configured to allow circulation of gas between said insert and the intermediate space.

[0002] The invention applies particularly to catalytic exchange reactors using a solid catalyst, in particular in powder form. Such a reactor is for example described in application FR3103714, in the name of one of the Applicants.

[0003] Such a reactor, however, presents production constraints, in particular due to the complex shape of the insert.

[0004] The invention aims to simplify the production of the reactor. To this end, the subject of the invention is a tubular reactor of the aforementioned type, in which the insert comprises at least a first and a second (tubes, extending respectively along a first and a second secondary axis; and said tubular reactor further comprises a support arranged in the intermediate space and fixed to each of the first and second tubes, the support holding the first and second tubes at a distance from each other perpendicular to the main axis, so that each of the first and second secondary axes extends parallel to the main axis.

[0005] According to other advantageous aspects of the invention, the tubular reactor comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0006] - the support comprises a first holding element, fixed respectively to the first and second tubes, said first holding element preferably comprising a first and a second hook;

[0007] - the support further comprises a mast extending into the envelope along the axis main, the first holding element extending radially around the mast;

[0008] - the first holding element has an openwork shape, allowing a fluid flow between a first and a second axial end of the envelope, the support being received in said envelope;

[0009] - the support further comprises a second holding element, fixed to the first and to the second tubes;

[0010] - each of the first and second tubes has a substantially circular section;

[0011] - at least one of the first and second tubes comprises a plurality of openings gas permeable, substantially aligned parallel to the first or second secondary axis;

[0012] - the support comprises a device for angular positioning of at least one of the first and second tubes, such that the plurality of openings are arranged substantially opposite the main axis relative to said first or second secondary axis;

[0013] - the tubular reactor comprises a plurality of first tubes and a plurality of second tubes, the reactor further comprising: a first end compartment, opening onto a first end of the first tubes; and a second end compartment, opening onto a second end of the second tubes.

[0014] The invention further relates to a method of manufacturing a tubular reactor as described above, comprising the following steps: producing the first and second tubes; and producing the support; then fixing said support to the first and second tubes; then introducing the support and the first and second tubes into the casing, so as to form the intermediate space.

[0015] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0016] [Fig-1] [Fig.l] is a longitudinal sectional view of a tubular reactor according to a embodiment of the invention;

[0017] [Fig.2] [Fig.2] is a cross-sectional view of the tubular reactor of [Fig.l]; and

[0018] [Fig.3] [Fig.3] is a sectional view of elements of the tubular reactor of Figures 1 and 2.

[0019] Figures 1 and 2 represent a tubular reactor 10 according to one embodiment of the invention.

[0020] More precisely, the reactor 10 is a tubular exchanger reactor with a fixed catalytic powder bed.

[0021] The reactor 10 comprises: a casing 12; an insert 14; and a support 15. In the embodiment shown, the reactor 10 further comprises: a bed 16 of catalytic powder; and a first 17 and a second 18 end compartment.

[0022] The envelope 12 has a tubular shape and extends along a main axis 20. More precisely, the envelope 12 comprises a tubular main body 19, having an elongated shape between a first 21 and a second 22 end along the main axis 20.

[0023] In the embodiment shown, the main body 19 comprises an internal wall 23 of cylindrical shape along the main axis 20 and of substantially circular section.

[0024] The envelope 12 further comprises a first 24 and a second 26 transverse walls versales, arranged respectively at the first 21 and at the second 22 ends of the main body 19 of said envelope 12. Each transverse wall 24, 26 is substantially flat and perpendicular to the main axis 20.

[0025] According to another embodiment (not shown), the envelope does not include the first transverse wall 24.

[0026] The insert 14 is arranged in the casing 12. More precisely, the casing 12 and the insert 14 delimit an intermediate space 28, contained in said casing 12 between the main body 19 and the insert 14. The intermediate space 28 is delimited axially by the first 24 and second 26 transverse walls of the casing 12.

[0027] The insert 14 comprises at least one first 30 and one second 32 tubes. More precisely, in the embodiment shown, the insert 14 comprises four tubes, namely two first tubes 30, 34 and two second tubes 32, 36. In a variant not shown, as specified below, the insert comprises a number of first and second tubes greater than two.

[0028] Each of the tubes 30, 32, 34, 36 extends in a substantially rectilinear manner along a secondary axis, respectively 40, 42, 44, 46, each of said secondary axes being parallel to the main axis 20.

[0029] In the embodiment shown, each of the tubes 30, 32, 34, 36 has a substantially circular section. Other tube section shapes may however be used, such as polygonal sections.

[0030] The insert 14 is configured to allow gas circulation between said insert 14 and the intermediate space 28. In the embodiment shown, each of the tubes 30, 32, 34, 36 comprises a plurality of openings 48 distributed over a length of said tube, parallel to the corresponding secondary axis 40, 42, 44, 46. Preferably, the openings 48 are distributed over one or more generatrices of the tube 30, 32, 34, 36. In the embodiment shown, the openings 48 are distributed over a single generatrix of each tube 30, 32, 34, 36.

[0031] Only some of the openings 48 of the first tubes 30, 34 are shown in [Fig.l]. However, the openings 48 are preferably distributed over more than 50% of a length of the corresponding tube, more preferably over more than 75% of said length.

[0032] As visible in [Fig.l], each of the first tubes 30, 34 extends between a first open end 50, close to the first end 21 of the casing 12, and a second closed end 52, close to the second end 22 of the casing 12.

[0033] Furthermore, each of the second tubes 32, 36 extends between a first closed end, close to the first end 21 of the casing 12, and a second open end 54, close to the second end 22 of the casing 12.

[0034] As visible in [Fig.l], the first open end 50 of each of the first tubes 30, 34 forms an axial projection relative to the casing 12. More precisely, the first open end 50 of each of the first tubes 30, 34 is inserted into an opening 56 of the first transverse wall 24 of the casing.

[0035] Similarly, the second open end 54 of each of the second tubes 32, 36 forms an axial projection relative to the casing 12. More precisely, the second open end 54 of each of the second tubes 32, 36 is inserted into an opening in the second transverse wall 26 of the casing.

[0036] Preferably, as in the embodiment shown, the insert 14 comprises the same number of first 30, 34 and second 32, 36 tubes; and said first 30, 34 and second 32, 36 tubes are arranged alternately around the main axis 20 of the envelope. According to a variant of the embodiment shown, the insert comprises three first tubes and three second tubes, arranged alternately around the main axis 20 of the envelope.

[0037] The support 15 is arranged in the intermediate space 28, between the first 24 and second 26 transverse walls of the envelope 12.

[0038] As detailed below, the support 15 is fixed to the casing 12 and to each of the first 30, 34 and second 32, 36 tubes, so that each of the secondary axes 40, 42, 44, 46 extends parallel to the main axis 20.

[0039] Furthermore, in the embodiment shown, the support 15 holds the tubes 30, 32, 34, 36 at a distance from each other perpendicular to the main axis 20.

[0040] Preferably, the support 15 comprises at least one holding element 62, 64. In the embodiment shown, the support 15 comprises a first 62 and a second 64 holding element.

[0041] In the embodiment shown, the support 15 comprises a mast 60 and at least one holding element 62, 64. More specifically, in the embodiment shown, the support 15 comprises a first 62 and a second 64 holding element.

[0042] In the embodiment shown, the first 62 and the second 64 holding elements are arranged close, respectively, to the first 21 and the second 22 ends of the envelope 12. In a variant not shown, the support 15 comprises a number of holding elements greater than or equal to three, said holding elements being distributed over a length of said mast.

[0043] The first holding element 62 and the first tubes 30, 34 are shown in section in [Fig. 3], perpendicular to the main axis 20.

[0044] Each holding element 62, 64 is fixed to each of the tubes 30, 32, 34, 36. More precisely, in the embodiment shown, each holding element comprises at least one first 71 and at least one second 72 hook. Each hook 71, 72 is fitted respectively on a first 30, 34 or on a second 32, 36 tube.

[0045] Preferably, the element 62, 64 is made of a material allowing elastic deformation of each hook 71, 72 when the corresponding tube 30, 32, 34, 36 is fitted.

[0046] In the embodiment shown, an opening 73 of each hook 71, 72 is oriented in a tangential direction relative to the main axis 20. In a variant not shown, an opening of each hook is oriented in a radial direction relative to the main axis 20.

[0047] In the embodiment shown, each hook 71, 72 comprises an end finger 74, in contact with the internal wall 23 of the main body 19 of the casing 12. The end fingers 74 make it possible in particular to maintain a minimum distance between each tube 30, 32, 34, 36 and the internal wall 23.

[0048] According to a variant not shown, the at least one holding element comprises rings capable of receiving the corresponding tubes 30, 32, 34, 36, or a plate in which openings are provided capable of receiving said tubes. However, preferably, a surface of each holding element 62, 64, perpendicular to the main axis 20, is less than an internal section of the casing 12. In other words, each holding element 62, 64 has an openwork shape, allowing a fluid flow between the first 21 and the second 22 ends of the casing, the support 15 being received in said casing.

[0049] In the embodiment shown, the support 15 also comprises a mast 60. The mast 60 extends in the casing 12 parallel to the main axis 20. In the embodiment shown, the mast 60 is aligned with the main axis 20.

[0050] More precisely, the mast 60 extends between a first and a second end, fixed respectively to the first 24 and to the second 26 transverse walls of the envelope 12.

[0051] In the embodiment shown, the mast 60 is formed of several sections 66, 67, 68 adjacent along the main axis 20.

[0052] Each holding element 62, 64 is fixed to the mast 60 and extends radially around said mast.

[0053] In the embodiment shown, each holding element 62, 64 has a central orifice 70. As seen in [Fig. 1], the mast 60 is secured to each holding element 62, 64 by insertion into the corresponding central orifice 70. More precisely, the ends of two adjacent sections 66, 67, 68 of the mast are secured to each other at the central orifice 70 of a holding element 62, 64.

[0054] Preferably, each of the tubes 30, 32, 34, 36 is fixed to the support 15 in a angular position defined relative to the main axis 20. In said angular position, the plurality of openings 48 of said tube is arranged substantially opposite the main axis 20, relative to the corresponding secondary axis 40, 42, 44, 46. More precisely, said angular position is such that the openings 48 of each tube are oriented towards the internal wall 23 of the main body of the casing 12.

[0055] More preferably, the reactor 10 comprises a member 75, 76 for angular positioning of each tube 30, 32, 34, 36.

[0056] In the embodiment shown, at least one of the hooks 71, 72 of each holding element 62, 64 comprises a lug 75 configured to fit into a notch 76 provided in the corresponding tube 30, 32, 34, 36, when said tube is in the angular position described above.

[0057] More particularly, in the embodiment shown, each of the first hooks 71 of the first holding element 62 is provided with a lug 75 as described above, capable of being inserted into a notch 76 of one of the first tubes 30, 34; and each of the second hooks 72 of the second holding element 64 is provided with a similar lug, capable of being inserted into a similar notch of one of the second tubes 32, 36.

[0058] In the embodiment shown, the bed 16 of catalytic powder is received in the intermediate space 28, radially between the insert 14 and the main body 19 of the casing 12, and axially between the first 24 and second 26 transverse walls. The support 15 is immersed in the bed 16 of catalytic powder.

[0059] Preferably, the main axis 20 is arranged substantially vertically; and a height of the bed 16 of catalytic powder is such that the openings 48 of the tubes 30, 32, 34, 36 are immersed in said bed 16.

[0060] Preferably, the openings 48 of the tubes 30, 32, 34, 36 are equipped with filters 78 permeable to gas but impermeable to solids, so as to avoid the introduction of catalytic powder into the tubes 30, 32, 34, 36 through said openings 48. For example, the filters 78 are in the form of covers slipped over the tubes 30, 32, 34, 36. Alternatively, the filters 78 are in the form of filter strips applied locally to the openings 48.

[0061] In the embodiment shown, the first 17 and the second 18 end compartments are arranged respectively at the first 21 and at the second 22 ends of the casing 12; the first open end 50 of each of the first tubes 30, 34 opens into the first end compartment 17; and the second open end 54 of each of the second tubes 32, 36 opens into the second end compartment 18.

[0062] In the embodiment shown, the reactor 10 further comprises: a gas inlet 80, opening onto the first end compartment 17; and an outlet 82 of gas, opening onto the second end compartment 18.

[0063] A method of manufacturing the reactor 10 will now be described.

[0064] The first 30, 34 and second 32, 36 tubes may be made from commercially available tubes, by drilling openings 48 along the length of each tube, adding a gas-permeable filter 78 over said openings and making notches 76 at the appropriate locations. The appropriate end 52 of each tube is closed, for example by means of a plug 84.

[0065] Preferably, stainless steel tubes are used to make the 30, 34 and second 32, 36 tubes. In particular, stainless steel tubes are preferable for the manufacture of a reactor intended for catalytic reactions using dihydrogen (H2).

[0066] The holding elements 62, 64 are for example produced by molding a thermoplastic material, then assembled to the sections 66, 67, 68 of the mast 60 to form the support 15. Said support 15 is then assembled to each of the tubes 30, 32, 34, 36, by elastic fitting of the hooks 71, 72 onto said tubes and by insertion of each lug 75 into the appropriate notch 76, as described previously.

[0067] The main body 19 of the envelope can be obtained from a commercially available tube. The assembly formed by the tubes 30, 32, 34, 36 and the support 15 is introduced into said main body 19, then the second transverse wall 26 is fixed to the second end 22 of said main body and to the corresponding end of the mast 60. The open ends 54 of the second tubes 32, 36 are introduced into the corresponding openings of the second transverse wall 26, as described above.

[0068] The main body 19 of the envelope is then arranged vertically, the second transverse wall 26 being oriented downwards. Catalytic powder is then poured into the envelope via the first end 21, so as to form the powder bed 16. The openwork shape of the holding elements 62, 64 allows the powder to flow over the entire height of the main body 19.

[0069] In the embodiment shown, the first transverse wall 24 is then fixed to the first end 21 of said main body and to the corresponding end of the mast 60. The open ends 50 of the first tubes 30, 34 are introduced into the corresponding openings 56 of the first transverse wall 24.

[0070] The first 17 and second 18 end compartments are then assembled to the first 24 and second 26 transverse walls. Alternatively, said first 17 and second 18 end compartments are formed in one piece, respectively with said first 24 and with said second 26 transverse walls.

[0071] The reactor 10 described above is thus obtained.

[0072] A method of implementing the reactor 10 will now be described.

[0073] A reactive gas, possibly formed from a gas mixture, is introduced into the first end compartment 17 through the gas inlet 80. Via the open ends 50, said reactive gas is distributed into the first tubes 30, 34, then passes through the openings 48 of said first tubes to the bed 16 of catalytic powder received in the intermediate space 28.

[0074] The reactive gas then flows into the bed 16 of catalytic powder, essentially along the internal wall 23 of the main body of the envelope 12. During this flow, the reactive gas undergoes a chemical reaction in contact with the catalyst(s) of the bed 16 of powder.

[0075] The gas flow then reaches the openings 48 of the second tubes 32, 36 adjacent to the first tubes 30, 34. The gas, loaded with product(s) of the catalytic reaction, then enters said second tubes 32, 36. The gas then enters the second end compartment 18, through the open ends 54 of said second tubes.

[0076] The gas is then discharged through outlet 82.

[0077] Such a method is preferably implemented for the synthesis of organic compounds, the reactive gas containing at least dihydrogen (H2) and carbon dioxide (CO2).

[0078] The reactor 10 described above is simple to produce from commercially available elements, in particular stainless steel tubes. Such a material is advantageously used to produce the insert 14, in particular due to its resistance to corrosion.

Claims

Claims

1. Tubular reactor (10), comprising: a casing (12), extending along a main axis (20); and an insert (14) arranged in said outer casing, the casing (12) and the insert (14) delimiting an intermediate space (28), capable of receiving a bed (16) of catalytic powder; the insert (14) being configured to allow gas circulation between said insert and the intermediate space; the tubular reactor being characterized in that the insert (14) comprises at least a first (30, 34) and a second (32, 36) tube, extending respectively along a first (40, 44) and a second (42, 46) secondary axis;and in that said tubular reactor further comprises a support (15) disposed in the intermediate space (28) and fixed to each of the first (30, 34) and second (32, 36) tubes, the support maintaining the first and second tubes at a distance from each other perpendicular to the main axis (20), so that each of the first (40, 44) and second (42, 46) secondary axes extends parallel to the main axis (20).;

2. Tubular reactor according to claim 1, wherein the support (15) comprises a first holding element (62, 64), fixed respectively to the first (30, 34) and to the second (32, 36) tubes, said first holding element preferably comprising a first (71) and a second (72) hook.

3. Tubular reactor according to claim 2, in which the support (15) further comprises a mast (60) extending in the casing (12) along the main axis, the first holding element (62, 64) extending radially around the mast.

4. Tubular reactor according to claim 2 or 3, in which the first holding element (62, 64) has an openwork shape, allowing fluid flow between a first (21) and a second (22) axial end of the casing, the support (15) being received in said casing.

5. Tubular reactor according to one of claims 2 to 4, in which the support (15) further comprises a second holding element (62, 64), fixed to the first (30, 34) and to the second (32, 36) tubes.

6. Tubular reactor according to one of the preceding claims, in which each of the first (30, 34) and second (32, 36) tubes has a substantially circular section.

7. A tubular reactor according to any preceding claim, wherein at least one of the first (30, 34) and second (32, 36) tubes comprises a plurality of gas-permeable openings (48) substantially aligned parallel to the first (40, 44) or second (42, 46) secondary axis.

8. Tubular reactor according to claim 7, wherein the support (15) comprises a device (75) for angular positioning of at least one of the first (30, 34) and second (32, 36) tubes, so that the plurality of openings (48) is arranged substantially opposite the main axis (20) relative to said first (40, 44) or second (42, 46) secondary axis.

9. Tubular reactor according to one of the preceding claims, comprising a plurality of first tubes (30, 34) and a plurality of second tubes (32, 36), the reactor further comprising: a first end compartment (17), opening onto a first end (50) of the first tubes; and a second end compartment (18), opening onto a second end (54) of the second tubes.

10. Method for manufacturing a tubular reactor (10) according to one of the preceding claims, comprising the following steps: - producing the first (30, 34) and second (32, 36) tubes; and producing the support (15); then - fixing said support to the first (30, 34) and second (32, 36) tubes; then - introducing the support and the first and second tubes into the casing (12), so as to form the intermediate space (28).

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