Liquid-phase fixed-bed catalytic reactor

Abstract

Title: Liquid-phase fixed-bed catalytic reactor The invention relates to a horizontal liquid-phase fixed-bed catalytic reactor comprising a reactor tube (1) extending along a horizontally oriented longitudinal axis (8) comprising a reaction zone (5) extending along the longitudinal axis (8) of the reactor tube (1) and configured to receive a fixed catalyst bed and a circulation of the liquid reactant and the liquid product and a circulation zone (6) of the gaseous product extending along the longitudinal axis (8) of the reactor tube (1), and a porous material (7) arranged at least at the interface of the circulation zone (6) and the reaction zone (5), the circulation zone (6) and the reaction zone (5) being arranged parallel to each other, the circulation zone (6) being stacked above the reaction zone (5). Figure for abstract: Fig.1

Description

Title of the invention: Liquid-phase fixed-bed catalytic reactor Technical field

[0001] The present invention relates to the technical field of catalytic reactors, in particular using solid catalysts. The invention will find its application more particularly for the implementation of reactions in the liquid phase resulting in the formation of a gas phase, for example the processes for dehydrogenation of a liquid resulting in the formation of a gas from one (or more) liquid reactant(s). The invention can be applied, for example, to the dehydrogenation reactions of molecules of the liquid organic hydrogen carrier (LOHC) type, such as the dehydrogenation reaction of butanediol (BDO) into γ-butyrolactone (GBL). The invention can also be applied to the decarbonylation (formation of CO) and decarboxylation (formation of CO2) reactions of carboxylic acid. STATE OF THE ART

[0002] LOHC hydrogen carriers have been developed to enable the storage and transport of hydrogen within a liquid. To recover the dihydrogen, it is necessary to pass the loaded carrier medium through a reactor to enable the release of the gaseous dihydrogen.

[0003] In particular, document US 2018 / 0290117 discloses a reactor for the dehydrogenation of a liquid vector. This shell-and-tube type reactor has a plurality of tubes arranged in an enclosure and oriented horizontally. The tubes, the seats of the chemical reaction, are semi-filled with a solid catalyst. The gas produced will be separated from the liquid vector since it will, by gravity, occupy the free space above the catalytic bed.

[0004] This reactor, however, has the disadvantage of being able to have a catalyst poorly distributed along each tube, for example following manipulations of the reactor, but also if the catalyst is carried along by the gas during the reaction, for example by a local fluidization phenomenon, which would also have the effect of having a degradation of the catalyst. This leads to a loss of contact between the catalyst and the reactant and therefore to a drop in yield.

[0005] The aim of the present invention is to propose a solution which makes it possible to propose a reactor which makes it possible to optimize the energy and chemical efficiency of the process.

[0006] Other objects, features and advantages of the present invention will become apparent from a consideration of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY

[0007] To achieve this objective, according to one embodiment, a liquid-phase horizontal fixed-bed catalytic reactor is provided comprising a reactor tube extending along a horizontally oriented longitudinal axis comprising an inlet intended to allow the entry of a liquid reactant, an outlet intended to allow the exit of a liquid product, an outlet intended to allow the exit of a gaseous product discharged from the liquid reactant, a reaction zone extending along the longitudinal axis of the reactor tube and configured to receive a fixed bed of catalyst and a circulation of the liquid reactant and the liquid product, a circulation zone for the discharged gaseous product extending along the longitudinal axis of the reactor tube, and a porous material arranged so as to form an interface of the circulation zone and the reaction zone, the circulation zone and the reaction zone being arranged parallel to each other,the circulation zone being stacked above the reaction zone.

[0008] Thus, the reactor according to the invention makes it possible to keep the catalyst separate from the circulation zone which is free and therefore reserved for the circulation of the gas formed by the reaction. The porous material confines the catalyst in the reaction zone. The porous material ensures a physical separation of the reaction zone and the circulation zone. The catalyst is correctly distributed in the reaction zone without risk of displacement by the gas, by manipulation of the tube or even by the liquid reagent or the liquid product.

[0009] The reactor according to the invention also makes it possible to resolve the problem of loss of contact between the liquid reagent and the solid catalyst since the volume of gas produced is separated by gravity. Another aspect relates to a reactor system comprising an enclosure extending along a longitudinal axis receiving several catalytic reactors as described above, the catalytic reactors are arranged parallel to each other, their longitudinal axis arranged parallel to the longitudinal axis of the enclosure, advantageously horizontally. BRIEF DESCRIPTION OF THE FIGURES

[0010] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

[0011] [Fig-1] [Fig. 1] represents a longitudinal sectional view of a catalytic reactor according to a first embodiment of the invention.

[0012] [Fig.2] [Fig.2] represents a developed view of the surface of a catalytic reactor according to [Fig.l].

[0013] [Fig.3] [Fig.3] represents a sectional view AA of a catalytic reactor according to [Fig.l].

[0014] [Fig.4] [Fig.4] represents a longitudinal sectional view of a catalytic reactor according to a variant of the first embodiment illustrated in [Fig.l].

[0015] [Fig.5] [Fig.5] represents a longitudinal sectional view of a catalytic reactor according to a second embodiment of the invention.

[0016] [Fig.6] [Fig.6] represents a sectional view BB of a catalytic reactor according to [Fig.5].

[0017] [Fig.7] [Fig.7] represents a longitudinal sectional view of a reactor system according to the invention of the tube / shell type in a liquid reactive and thermal fluid co-current configuration.

[0018] [Fig.8A] [Fig.8A] represents a CC sectional view of the reactor system according to [Fig.7] illustrating a cover plate at the inlet of the liquid reactant.

[0019] [Fig.8B] [Fig.8B] represents a sectional view DD of the reactor system according to [Fig.7] illustrating a cover plate at the liquid product outlet.

[0020] [Fig.9] [Fig.9] represents a developed view of the surface of a reactor system according to [Fig.7].

[0021] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications. DETAILED DESCRIPTION

[0022] Before commencing a detailed review of embodiments of the invention, optional features which may possibly be used in combination or alternatively are set out below:

[0023] According to one example, the cross-sectional area of ​​a reactor tube comprises the cross-sectional area of ​​the circulation zone and the cross-sectional area of ​​the reaction zone.

[0024] According to one example, the cross-sectional area of ​​the reaction zone represents at most 95% of the cross-sectional area of ​​a reactor tube, preferably 90%.

[0025] According to one example, the cross-sectional area of ​​the reaction zone represents at least 10% of the cross-sectional area of ​​a reactor tube, preferably 20%, preferably 50%.

[0026] According to one example, the catalyst of the fixed bed is in solid form of granules or powder with a particle size of less than one centimeter, preferably between 200 μm and 5 mm.

[0027] According to one example, the porous material has a pore size smaller than the particle size of the catalyst.

[0028] According to one example, the porous material has a pore size configured to allow circulation of the gaseous product, by which is meant circulation of the gaseous product from the reaction zone to the circulation zone.

[0029] According to one example, the inlet and the outlet are arranged respectively at a longitudinal end of the tube. Advantageously, the inlet and the outlet are arranged along the longitudinal axis of the tube.

[0030] According to one example, the discharge is arranged in the upper part of the tube, advantageously in a direction radial to the tube. Advantageously, the discharge is arranged along an axis transverse to the longitudinal axis of the tube.

[0031] According to one example, the catalytic reactor comprises an inlet plate arranged at the inlet of the tube comprising a first opening arranged opposite the reaction zone so that the liquid reactant enters the tube via the reaction zone.

[0032] According to one example, the cross-sectional area of ​​the first opening represents 100% of the cross-sectional area of ​​the reaction zone.

[0033] According to one example, the catalytic reactor comprises an outlet plate arranged at the outlet of the tube comprising a second opening arranged facing the reaction zone so that the liquid product and possibly the unreacted liquid reactant exits the tube through the reaction zone.

[0034] According to one example, the cross-sectional area of ​​the second opening represents 100% of the cross-sectional area of ​​the reaction zone.

[0035] According to one example, the catalytic reactor comprises a porous plug, advantageously non-reactive, i.e. not containing catalyst, arranged in the reactor tube at the outlet intended to maintain the fixed bed of catalyst in the reaction zone and to allow the exit of the liquid product and possibly the unreacted liquid reagent.

[0036] According to one example, the catalytic reactor comprises retention elements arranged in contact with the porous material in the circulation zone and having an inclination with the porous material so as to capture the liquid reactant or the liquid product passing through the porous material to redirect it towards the reaction zone.

[0037] Advantageously, the retention elements 14 form an angle greater than 0° and less than 180° with the porous material 7.

[0038] Advantageously, the retention elements 14 are oriented towards the inlet 2.

[0039] Advantageously, the catalytic reactor comprises a thermal energy source configured to supply heat to the reaction zone 5.

[0040] According to one example, the system includes a thermal energy source configured to provide heat to the reaction zone.

[0041] For the remainder of the description, 'top' and 'bottom', or their derivatives, are understood to mean a quality of relative positioning of an element of the reactor or reactor system when the latter is functionally installed, the 'top' being oriented away from the ground and the 'bottom' being oriented towards the ground. The upper end is located at the top and the lower end is located at the bottom.

[0042] Vertical means that which is parallel to the direction of gravity given in particular by the plumb line and horizontal that which is perpendicular to the vertical. The top and the bottom being vertically opposed.

[0043] By horizontal we mean that which is perpendicular to the vertical.

[0044] Transverse means a direction perpendicular to a longitudinal direction. A transverse section is a section perpendicular to the longitudinal axis.

[0045] Upstream and downstream, inlet, outlet, at a given point are taken in reference to the direction of circulation of the fluid.

[0046] A parameter "substantially equal / greater / less than" or "of the order of" a given value means that this parameter is equal / greater / less than the given value, to within plus or minus 10%, or even to within plus or minus 5%, of this value.

[0047] Fluidly connected or in fluidic connection means when a line provides a connection by or in which a fluid circulates.

[0048] Hot, cold, cooled means a temperature relative to another point in the system.

[0049] By porosity of a material is meant the volume not occupied by the solid matter of the material, relative to the apparent volume of the material. This volume proportion can be occupied by vacuum, gas or a liquid. This proportion is delimited by a plurality of cavities.

[0050] By "cavity" is meant a volume not occupied by the material and formed in the material. According to one example, the porosity of the material is homogeneous, that is to say that the porosity per unit of volume is substantially identical in any portion of the same determined size of the material.

[0051] By "open" porosity, we mean a complex cavity which communicates with the exterior, the environment of the material. In open porosity, the cavities can be of dimensions of the order of one millimeter to a few hundred nanometers.

[0052] In the context of the present invention, a porous material with so-called "open" porosity designates a material having a porosity at least partly in communication with the environment of the material. Thus, a gas can pass through the open material. The porosity of the material may in particular be greater than 30%, or even 40%, or even 60%, or even 70% of the apparent volume of the material.

[0053] The invention relates to a horizontal fixed bed catalytic reactor in liquid phase. The catalytic reactor according to the invention allows the formation of a gas phase.

[0054] The catalytic reactor according to the invention is configured to receive a solid catalyst forming a horizontally arranged catalytic bed. This means at least that the circulation of the liquid reactant in the reactor is intended to be oriented in a horizontal direction. The catalytic reactor according to the invention is configured to ensure the chemical reaction of a liquid reactant in contact with a catalyst to produce a gaseous product and a liquid product.

[0055] More specifically, the liquid reactant is, for example, a charged liquid vector intended to be discharged or also called a charged liquid carrier medium. For example, in the context of a dehydrogenation reaction, the liquid reactant is an organic hydrogen storage liquid, for example in the form of a cyclic hydrocarbon or a linear diol. The carrier medium is a hydrogen carrier medium which is chemically bonded thereto. Such a carrier medium is, for example, known as a liquid organic hydrogen carrier (LOHC).

[0056] The gaseous product is for example hydrogen or carbon monoxide or carbon dioxide.

[0057] The liquid reactant also produces a liquid product. The liquid product is, for example, the discharged liquid vector or also called discharged liquid carrier medium.

[0058] The catalyst is for example chosen from a co-precipitated catalyst of CuO-ZnO-Al2O3 or metal (Cu, Co, Pt, Rh, Pd, Ru, Ni) supported. The support can be an oxide (Al2O3, SiO2, CeO2, TiO2), carbon or a composite support (Al2O3-TiO2 for example).

[0059] The catalyst is advantageously in a solid form such as, for example, granules or powder with a particle size of less than a few centimeters, preferably less than a few millimeters, and preferably between 1 μm and 5 mm, more precisely between 200 μm and 5 mm. By way of example, the catalyst has a spherical shape, or is of the granule, ring or tablet type and alternatively in the form of a catalyst deposited on a monolith-type structure made of ceramic or aluminum or of the metal foam type (steel, aluminum).

[0060] The reactor according to the invention comprises a reactor tube 1 extending along a longitudinal axis 8. In operation, the tube 1 is arranged horizontally, that is to say that the longitudinal axis 8 of the tube 1 is oriented horizontally.

[0061] The tube 1 has a hollow profile preferably of circular section to form a cylindrical tube. However, other hollow profile shapes, for example having a square, rectangular, triangular, pentagonal, hexagonal or other polygonal outline, are also possible. The tube 1 may also have an oval outline.

[0062] The tube 1 comprises an inlet 2 intended to allow the entry of the liquid reagent, also called charged liquid vector.

[0063] The tube 1 also comprises an outlet 3 intended to allow the exit of the liquid product, also called discharged liquid vector.

[0064] The tube 1 also comprises an evacuation 4 intended to allow the exit of the gaseous product, in particular discharged from the loaded liquid vector.

[0065] Preferably, the inlet 2 and the outlet 3 are arranged at each of the ends of the tube 1. The tube 1 comprises two opposite emerging ends advantageously forming respectively the inlet 2 and the outlet 3 of the reagent and / or the liquid product.

[0066] According to one embodiment, the evacuation 4 of the gaseous product is advantageously formed in the upper part of the tube 1 and preferably at one end of the tube 1, in particular at the opening end forming the outlet 3. The tube 1 is formed of an envelope 38 which is advantageously partially open on its upper part to form the evacuation 4. The evacuation 4 is for example formed by perforations in the envelope 38 of the tube 1 or by a grid arranged in an opening formed in the envelope 38 of the tube 1. The evacuation of the gaseous product is carried out by the evacuation 4 at the upper periphery 41 of one end of the tube 1. Preferably, the evacuation 4 is formed on a sector of the envelope 38 called the upper 41, because it does not extend below a median plane intersecting the section of the tube 1 in the middle.The evacuation of the gaseous product is advantageously carried out in a radial direction 9 to the tube 1, more precisely the radial direction 9 is perpendicular to the longitudinal axis 8 of the tube 1.

[0067] According to the invention, the tube 1 comprises a reaction zone 5 intended to receive the catalytic bed. The reaction zone 5 extends into the tube 1. Preferably, the tube 1 comprises a casing 38 defining an interior volume 39 in which the reaction zone 5 is arranged. Advantageously, the reaction zone 5 extends in a direction parallel to the longitudinal axis 8 of the tube 1. The reaction zone 5 extends between the inlet 2 of the liquid reactant and the outlet 3 of the liquid product. The reaction zone 5 is advantageously also configured to allow the circulation of the liquid reactant and the liquid product. This arrangement ensures optimal contact between the catalyst and the liquid reactant. The reaction zone 5 is configured to prevent the liquid reactant and then the liquid product from passing into the circulation zone 6 of the tube 1.Advantageously, the size of the pores of the porous material 7 described below is smaller than the particle size of the catalyst; the passage of the liquid reagent and then of the liquid product from the reaction zone 5 to the circulation zone 6 would cause a pressure drop which does not promote said passage.

[0068] The reaction zone 5 advantageously rests on the lower part 40 of the tube 1. The catalyst being solid, it is placed in the bottom of the interior volume 39 of the tube 1 and rests on the lower part 40 of the casing 38 of the tube 1.

[0069] The tube 1 also comprises a circulation zone 6 for the gaseous product. The circulation zone 6 extends in the tube 1, that is to say in the interior volume 39 defined by the casing 38 of the tube 1. Advantageously, the circulation zone 6 extends in a direction parallel to the longitudinal axis 8 of the tube 1.

[0070] Preferably, the circulation zone 6 is advantageously formed in the upper part 41 of the tube 1. Thus, the gas produced or discharged from the liquid reagent rises by gravity in the upper part 41 of the tube 1. The circulation zone 6 is advantageously empty, that is to say that it does not comprise a catalyst or solid material ensuring free circulation of the gas produced.

[0071] The circulation zone 6 advantageously extends to the evacuation 4 and preferably from the end of the tube 1 forming the inlet 2 of the liquid reagent.

[0072] The circulation zone 6 and the reaction zone 5 are advantageously arranged parallel to each other. Advantageously, the circulation zone 6 is stacked above the reaction zone 5.

[0073] According to the invention, the tube 1 comprises a porous material 7 arranged in the interior volume 39 to at least form an interface between the reaction zone 5 and the circulation zone 6.

[0074] The porous material 7 makes it possible to physically separate the reaction zone 5 comprising the catalyst from the gas circulation zone 6.

[0075] The catalyst is confined in the reaction zone 5 without risk of being displaced during the movement of the reactor or during the circulation of fluids (liquid and gas) in the tube 1.

[0076] Advantageously, the porous material 7 is configured to be impermeable to the catalyst. The porous material 7 has a pore size smaller than the particle size of the catalyst.

[0077] Preferably, the porous material 7 has an open porosity allowing the circulation of the gaseous product. The porous material 7 is advantageously permeable to the gaseous product, more specifically, to dihydrogen, and / or to carbon monoxide and / or to carbon dioxide.

[0078] According to a preferred possibility, the porous material 7 is configured to also contain in the reaction zone 5, the liquid reactant and the liquid product. Advantageously, the size of the pores of the porous material 7 being smaller than the particle size of the catalyst, the passage of the liquid reactant then of the liquid product from the reaction zone 5 to the circulation zone 6 is not favored in that this passage would cause a pressure drop. This arrangement advantageously allows the liquid reactant circulating in the reaction zone 5 not to be diverted to the circulation zone 6, that is to say not to “bypass” the reaction zone 5 in favor of the circulation zone 6. This configuration thus ensures optimal contact between the catalyst and the liquid reagent.

[0079] By way of example, the porous material has a pore size with a dimension greater than a few tens of nanometers and less than 1 millimeter, preferably less than 200 micrometers, more precisely less than 100 micrometers, more precisely less than 50 micrometers.

[0080] The gaseous product, for example dihydrogen H2, is separated from the liquid phase, i.e. the liquid reactant and the liquid product by gravity and physically passes through the porous material 7 since the diffusion of the gaseous product and in particular of the hydrogen is rapid and easy due to the size of the molecule. It is not necessary to impose a pressure difference on either side of the porous material 7 for the gas to be separated from the reaction zone 5.

[0081] According to a first embodiment, the porous material 7 only forms the interface between the reaction zone 5 and the circulation zone 6. The interior volume 39 of the tube 1 comprises, from bottom to top, the reaction zone 5 advantageously comprising the catalytic bed, then the porous material 7, then the circulation zone 6.

[0082] According to one possibility, the catalytic bed is formed by the catalyst in solid form as described above filling the volume of the reaction zone 5. According to this possibility, the porous material 7 is configured to have a pore size smaller than the particle size of the catalyst so as to maintain the catalyst in the reaction zone 5.

[0083] According to another possibility, the catalytic bed is formed by the catalyst deposited on a solid structure 43 filling the volume of the reaction zone 5.

[0084] The solid structure 43 is for example of the monolith type made of ceramic or aluminum or metal foam made of steel or aluminum. According to this possibility, the porous material 7 is configured to have a pore size smaller than the open porosity of the solid structure 43 receiving the catalyst.

[0085] The porous material 7 forms an upper interface 42 with the circulation zone 6 and advantageously a lower interface 44 with the reaction zone 5.

[0086] By way of example, the porous material 7 may be a structured packing such as blocks adjusted to the internal volume 39 of the tube 1, plates, sheets or grids, or an unstructured packing of the Raschig ring type made of ceramic material in stoneware or porcelain, or in steel, or of the Berl saddle or Intalox® type in ceramic. The porous material 7 may also be a metal foam made of steel, titanium or aluminum or a sintered metal type PORAL® made of steel, nickel or bronze. According to one possibility, the porous material 7 and the solid structure 43 are of the same nature but preferably have different pore sizes so that the pore size of the porous material 7 is smaller than the pore size of the solid structure 43.

[0087] The upper interface 42 of the porous material 7 with the circulation zone 6 is by flat example and advantageously extending along the longitudinal axis 8 of the tube 1. According to variants, the upper interface 42 and / or the lower interface 434 may have various shapes, for example sinusoidal, square, triangular or sawtooth. This arrangement makes it possible to modulate the thickness of catalyst in the reaction zone 5.

[0088] The porous material 7 is held in the interior volume 39 of the tube 1 by fixing means such as, for example, cleats, which can be welded or screwed, in particular at the inlet 2 and outlet 3 of the tube 1. Typically, at least two cleats hold the porous material 7 on either side of its width at the inlet 2 and at least two cleats hold the porous material 7 on either side of its width at the outlet 3 of the tube. Ideally, the porous material 7 is held between four cleats on either side of its width and height at the inlet 2 and four cleats on either side of its width and height at the outlet 3.

[0089] The mass of catalyst loaded into tube 1 is a function of the desired productivity at the reactor outlet.

[0090] Preferably, the tube 1 is partially filled with catalyst. More precisely, the reaction zone 5 does not fill the entire interior volume 39 of the tube 1. Preferably, the cross-sectional area of ​​the tube 1 consists of the cross-sectional area 19 of the circulation zone 6, the cross-sectional area of ​​the porous material 7 and possibly the cross-sectional area 18 of the reaction zone 5 if the porous material 7 is limited to the interface 42 between the circulation zone 6 and the reaction zone 5, as in [Fig.3].

[0091] Advantageously, the cross-sectional surface 18 of the reaction zone 5 represents a maximum of 95% of the cross-sectional surface of the tube 1, preferably 90%, preferably 80%, preferably 70%, preferably 60%, preferably 50%.

[0092] Advantageously, the cross-sectional surface 18 of the reaction zone 5 represents at least 10% of the cross-sectional surface of the tube 1, preferably 20%, preferably 30%, preferably 40%, preferably 5%, preferably 50%.

[0093] Depending on the embodiment, the cross-sectional area of ​​the porous material 7 represents of the order of 2% to 35% of the cross-sectional area of ​​the tube 1 as illustrated in [Fig.3].

[0094] Advantageously, the cross-sectional surface 19 of the circulation zone 6 represents a maximum of 40% of the cross-sectional surface of the tube 1, preferably 30%, preferably 20%, preferably 10%, preferably 5%.

[0095] Advantageously, the cross-sectional surface 19 of the circulation zone 6 re presents at least 5% of the cross-sectional area of ​​the tube 1, preferably 10%, preferably 20%, preferably 30%, preferably 35%, preferably 40%.

[0096] The tube 1 comprises, according to one embodiment, retention elements 14. The retention elements 14 are advantageously arranged in the circulation zone 6. Preferably, the retention elements 14 extend from the porous material 7 into the circulation zone 6. More precisely, the retention elements 14 are peaks or plates in contact with the porous material 7, more precisely at the upper interface 42 of the porous material 7. The retention elements 14 advantageously form an angle with the upper interface 42 of between 0° and 180° and preferably different from 0° and 180° and preferably 90°, i.e. greater than 0° and less than 90° or greater than 90° and less than 180°. The retaining element 14 extends in a direction comprising a direction perpendicular to the longitudinal axis 8 of the tube 1 and a direction parallel to the longitudinal axis 8 of the tube 1.Preferably, the perpendicular direction is oriented in the circulation zone 6. As an example illustrated in figures 1, 4, 5, 7, the retention elements 14 are oriented towards the entrance 2.

[0097] The retention elements 14 are configured so as not to obstruct the porosity of the porous material 7 and to allow the circulation of the gaseous product by gravity and the circulation of the gaseous product in the circulation zone 6.

[0098] The retention elements 14 are for example placed along the longitudinal axis 8 of the tube 1, above the porous material 7 and make it possible to prevent the entrainment of the liquid phase, the liquid reagent and / or the liquid product by the gaseous product. The liquid phase possibly carried away with the gaseous product is blocked by the retention elements 14 and returns to the reaction zone 5 by flowing along the retention means 14.

[0099] The reactor according to the invention advantageously comprises an inlet plate 10 arranged at one end of the tube 1 forming the inlet 2 for the liquid reactant. The inlet plate 10 comprises a first opening 11 arranged opposite the reaction zone 5. Preferably, the first opening 11 has a cross-sectional area of ​​the order of the cross-sectional area of ​​the reaction zone 5. The first opening 11 corresponds in shape and cross-sectional area to the shape and surface area of ​​the reaction zone 5 in cross-section. The cross-sectional area of ​​the first opening 11 corresponds to the cross-sectional area of ​​the reaction zone 5. This inlet plate 10 and its first opening 11 make it possible to direct the liquid reactant into the reaction zone 5.

[0100] This configuration makes it possible to limit the risks that the liquid reagent passes above the reaction zone 5 into the circulation zone 6 which has less constraints, and therefore that a quantity of the liquid reagent is heated, but does not react, because it is not in contact with the catalyst. This arrangement therefore optimizes the energy and chemical efficiency of the process and the device.

[0101] In this embodiment, the porous plug 15 arranged at the end of the tube 1 forming the inlet 2 cooperates for example with the first opening 11.

[0102] The reactor according to the invention advantageously comprises an outlet plate 12 arranged at one end of the tube 1 forming the outlet 3 of the liquid reactant. The outlet plate 12 comprises a second opening 13 arranged opposite the reaction zone 5. Preferably, the second opening 13 has a cross-sectional area of ​​the order of the cross-sectional area of ​​the reaction zone 5. The second opening 13 corresponds in shape and cross-sectional area to the shape and surface area of ​​the reaction zone 5 in cross-section. The cross-sectional area of ​​the second opening 13 corresponds to the cross-sectional area of ​​the reaction zone 5 in cross-section. This outlet plate 12 and its second opening 13 make it possible to evacuate the liquid product and possibly the unreacted liquid reactant from the reaction zone 5.

[0103] According to one possibility, the first opening 11 and the second opening 13 are identical. Preferably, the inlet plate 10 and the outlet plate 12 are identical as for example illustrated in FIGS. 7, 8a and 8b.

[0104] The tube 1 advantageously comprises a porous plug 15. The porous plug 15 is arranged in the tube 1 at the end forming the outlet 3 for the liquid product and possibly the unreacted liquid reagent. The porous plug 15 is arranged in the reaction zone 5. Preferably, the porous plug 15 is not reactive, that is to say that the porous plug 15 does not comprise a catalyst. Advantageously, the porous plug 15 is arranged in the reaction zone 5 opposite the outlet 4 formed in the upper part of the tube 1. The porous plug 15 has the function of maintaining the catalytic bed in the reaction zone 5. The porous plug 15 is impermeable to the catalyst. The porous plug is configured to allow the liquid phase comprising the liquid product and possibly the unreacted liquid reagent to pass through. The porous plug is for example made of sintered porous material (i.e. Steel, Nickel or bronze of the PORAL® type, etc.).The porous plug 15 has a pore size smaller than the particle size of the catalyst that it must maintain in the reaction zone 5. Following the example of PORAL® type sintered metals, this pore size can be between 3 μm and 50 μm. According to one possibility, the porous plug 15 is made of the same material as the porous material 7.

[0105] According to one embodiment, the tube 1 comprises a porous plug 15 arranged in the tube 1 or partially or totally outside the tube 1 at the end forming the inlet 2 of the liquid reagent. The porous plug 15 is advantageously identical to this which is described for the porous plug 15 arranged at outlet 3.

[0106] According to a preferred embodiment, the liquid reagent and the gaseous product circulate in the tube 1 in co-current, that is to say in the same direction. According to this embodiment, the evacuation 4 and the outlet 3 are advantageously arranged at the same end of the tube 1, opposite the end receiving the inlet 2.

[0107] The reactor according to the invention is in particular intended to allow endothermic reactions. For this purpose, the tube 1 can be placed in a furnace ensuring the supply of thermal energy necessary for the endothermic reaction to take place. According to another possibility, the reactor comprises a heat source intended to provide the thermal energy necessary for the reaction to take place. For example, the reactor comprises heating elements 17 which may be electrical, arranged for example in contact with the tube 1, in particular outside the casing 38 of the tube 1, as illustrated in [Fig.4]. The heating elements 17 can also be arranged in conduction of the porous material 7 and / or of the solid structure holding the catalyst in the reaction zone 5, in particular if it is a metal foam or a thermally conductive material.

[0108] According to an alternative, the reactor comprises an annular tube receiving the tube 1 configured to ensure circulation of a thermal fluid in the annular space formed between the annular tube and the tube 1. Coupling with an exothermic reaction can also be envisaged.

[0109] According to one aspect, the invention relates to a reactor system comprising an enclosure 20 extending along a longitudinal axis 32. The enclosure 20 is configured to receive a plurality of catalytic reactors as described above. The catalytic reactors are arranged parallel to each other, the longitudinal axis 8 of each reactor tube 1 being parallel to the longitudinal axis 32 of the enclosure 20. Advantageously, the reactor system is configured so that in operation the longitudinal axis 32 of the enclosure 20 is horizontal.

[0110] The reactor system is advantageously of the tube / shell type.

[0111] According to one possibility, all the tubes 1 have an identical configuration. The tubes 1 are for example shaped as cylindrical tubes. It is also conceivable that the tubes 1 are configured differently, in particular with a different contour and / or with different cross-sections.

[0112] Advantageously, in the reactor system according to the invention, the inlet plate 10 is advantageously shared for all the tubes 1. Thus, the reactor system comprises an inlet plate 10 provided with several first openings 11 arranged opposite each reaction zone 5 of each tube 1. The inlet plate 10 advantageously has a cross-sectional area substantially equal to the cross-sectional area of ​​the enclosure 20.

[0113] Advantageously, in the reactor system according to the invention, the outlet plate 12 is advantageously shared for all the tubes 1. Thus, the reactor system comprises an outlet plate 12 provided with several second openings 13 arranged opposite each reaction zone 5 of each tube 1. The outlet plate 12 advantageously has a cross-sectional area substantially equal to the cross-sectional area of ​​the enclosure 20.

[0114] The enclosure 20 advantageously comprises a supply of the liquid reagent 29, a withdrawal of a gaseous product 30 and a withdrawal 31 of a liquid product and possibly of the unreacted liquid reagent. For example, the supply 29 is made through the upper part of the enclosure 20 as illustrated in [Fig.7] or it is made through the lower part of the enclosure.

[0115] According to one embodiment, the enclosure 20 comprises a distribution pipe 33 arranged in fluid connection between the supply 29 and the inlet 2 of each tube 1 to supply each tube 1 with liquid reagent.

[0116] According to one embodiment, the enclosure 20 comprises a recovery pipe 36 for the liquid product, and possibly for the unreacted liquid reagent, arranged in fluid connection between the outlet 3 of each tube 1 and the withdrawal 31.

[0117] According to one embodiment, the enclosure 20 comprises a gaseous product withdrawal pipe arranged in fluid connection between the discharge 4 of each tube 1 and the withdrawal 30, as illustrated in [Fig.7].

[0118] According to one possibility, the reactor system comprises a thermal energy source configured to supply heat to the reaction zones 5. Preferably, the thermal energy source is a thermal fluid or heat transfer fluid. The reactor system is configured so that the thermal fluid circulates in the enclosure 20 around the tubes 1. The thermal fluid circulates in a space intermediate the tubes 1. The enclosure 20 comprises a supply 27 of the thermal fluid in the enclosure 20 and an evacuation 28 of the thermal fluid outside the enclosure 20. The thermal fluid makes it possible to transfer the heat to the liquid reactant. For example, the supply 27 and the evacuation 28 of the thermal fluid are made via the upper part of the enclosure 20 as illustrated in FIGS. 7, 9.

[0119] The heat transfer fluid can flow co-currently or counter-currently to the direction of circulation of the liquid reactant. Co-current is understood to mean if the thermal fluid and the liquid reactant flow in the same direction and counter-current is understood to mean if the thermal fluid and the liquid reactant flow in an opposite direction.

[0120] Advantageously, the system comprises baffles 34 allowing the thermal fluid to snake along the tubes 1.

[0121] According to one possibility, the reactor system comprises a plenum 22 and / or a plenum 23. The plenum 22 and the plenum 23 are arranged at the longitudinal ends of enclosure 20.

[0122] The reactor system comprises a plurality of flanges 24, 25, 26 for assembling the different parts of the system.

[0123] The length of the tube 1 is greater than the length of the thermal fluid circulation zone, i.e. the length between the supply 27 and the discharge 28 of the thermal fluid in the enclosure 20. In fact, the discharge 4 of the gas produced is formed over a length 1 of the tube 1. Advantageously, the reaction zone 5 comprises the porous plug 15 extending over a length 1 arranged opposite the discharge zone 4. This arrangement makes it possible to maintain the catalyst in the reaction zone 5 heated by the circulation of the thermal fluid.

[0124] During operation, the liquid reactant is injected into the tube 1 through the inlet 2 at the reaction zone 5. Preferably, the pressure in the reaction zone 5 is between 0 and 20 bars absolute, preferably between 1 and 5 bars absolute. Preferably, the temperature in the reaction zone 5 is lower than the vaporization temperature of the liquid reactants and products and preferably higher than 80°C.

[0125] Advantageously, the flow rate of the liquid reagent at the inlet 2 of the tube 1 is non-zero and less than 500 l / min, preferably between 0.5 and 20 l / min. The liquid product and possibly the unreacted liquid reagent exit the tube 1 through the outlet 3 at the level of the reaction zone 5. The gaseous product is physically separated from the liquid all along the tube 1 and is evacuated through the evacuation 4. Examples

[0126] A reactor system according to the invention can be implemented in the context of the dehydrogenation of a LOHC. For example, 1,4-butanediol (BDO) can be dehydrogenated into gamma-butyrolactone (GBL) in order to release 2 moles of H2 between 150 and 220 °C and 1 and 5 bars.

[0127] In the case of a catalytic reactor comprising a single reactor tube 1 comprising a reaction zone 5 corresponding to a half-tube and a circulation zone 6 corresponding to a half-tube separated in the length direction by a porous material 7 of the metal foam type adjusted to the section of the tube 1 and of pore size smaller than the particle size of the catalyst. This porous material 7 is held in the tube 1 by four cleats at the inlet 2 of the tube 1 and four cleats at the outlet 3 of the tube 1.

[0128] The reaction zone 5 is filled with a solid catalyst suitable for carrying out the BDO dehydrogenation reaction, for example a CuO-ZnO-A12O3 co-precipitated catalyst. The catalyst is in the form of granules. These granules are confined in the reaction zone 5 by means of the porous material 7 of the metal foam type.

[0129] A circulation of a thermal fluid in an annular tube to tube 1 makes it possible to supply the reaction heat.

[0130] Preferably, after reduction of the catalyst, under typical H2 / Ar conditions at 300°C for several hours, the temperature of the catalytic reactor is lowered to 180°C under an inert flow in order to purge the hydrogen used during the reduction of the catalyst.

[0131] Preferably, the reaction is carried out at atmospheric pressure.

[0132] The liquid BDO loaded with hydrogen is supplied by a supply 29 which serves the reaction zone 5 of the tube 1 by means of an inlet plate 10 in which a first opening 11 in the form of a half-tube which can advantageously be provided with a porous inlet plug of the sintered porous type makes it possible to preferentially supply the reaction zone 5 of the tube 1.

[0133] Upon contact with the solid catalyst, the BDO (liquid) converts into GBL (liquid) and H2 (gas). The hydrogen formed during the dehydrogenation reaction is physically separated from the liquid by gravity along the entire length of the tube 1. Thus, it migrates by gravity into the circulation zone 6, without catalyst, where it can circulate freely. In this way, the formation of the gas phase does not result in a loss of contact between the liquid reactant and the solid catalyst.

[0134] The hydrogen formed is recovered in a collection chamber via an evacuation 4 formed at the upper periphery of the tube. A withdrawal 30 preferably located in the upper part of the enclosure makes it possible to recover the gas formed. An outlet plate 12 identical to the inlet plate 10, with a second opening 13 in the form of a half-tube provided with a porous plug 15, for example a sintered porous one, makes it possible to recover the liquid from the tube 1. A liquid withdrawal pipe 36 makes it possible to convey the liquid to the withdrawal 31.

[0135] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

[0136] List of references 1. Tube 2. Inlet of charged carrier liquid medium 3. Outlet of discharged carrier liquid medium 4. Evacuation of the gaseous product 5. Reaction zone 6. Traffic area 7. Porous material 8. Longitudinal axis of the tube 9. Radial direction 10. Entrance plate 11. First opening 12. Exit plate 13. Second opening 14. Retention elements 15. Porous plug 16. Direction of flow of the liquid carrier medium 17. Heating element 18. Cross-sectional area of ​​the reaction zone 19. Cross-sectional area of ​​the circulation area 20. Pregnant 21. Body 22. Plenum 23. Plenum 24. Bride 25. Bride 26. Bride 27. Thermal fluid supply 28. Evacuation of thermal fluid 29. Feeding of the charged liquid carrier medium 30. Withdrawal of the produced gas 31. Withdrawal of the discharged liquid carrier medium 32. Longitudinal axis of the reactor system 33. Distribution cane for the charged carrier liquid medium 34. Chicane 35. Thermal fluid circulation zone 36. Discharged carrier liquid medium recovery tube 38. Envelope 39. Interior volume 40. Lower part 41. Upper part 42. Upper interface 43. Solid structure 44. Lower interface

Claims

Claims

1. A liquid-phase horizontal fixed-bed catalytic reactor comprising a reactor tube (1) extending along a horizontally oriented longitudinal axis (8) comprising: i. An inlet (2) for allowing the entry of a liquid reactant, ii. An outlet (3) for allowing the exit of a liquid product and optionally unreacted liquid reactant, iii. An outlet (4) for allowing the exit of a gaseous product, iv. A reaction zone (5) extending along the longitudinal axis (8) of the reactor tube (1) and configured to receive a fixed bed of catalyst and a circulation of the liquid reactant and a liquid product, v.A circulation zone (6) of the gaseous product extending along the longitudinal axis (8) of the reactor tube (1), the circulation zone and the reaction zone being arranged parallel to each other, the circulation zone being stacked above the reaction zone; characterized in that the reactor comprises a porous material (7) extending along the longitudinal axis (8) of the tube 1 and arranged in the tube (1) to form an interface between the circulation zone (6) and the reaction zone (5).

2. A catalytic reactor according to the preceding claim wherein the cross-sectional area of ​​a reactor tube (1) comprises a cross-sectional area (19) of the circulation zone (6) and a cross-sectional area (18) of the reaction zone (5).

3. Catalytic reactor according to any one of the preceding claims in which the cross-sectional area (18) of the reaction zone (5) represents at most 95% of the cross-sectional area of ​​a reactor tube (1), preferably 90%.

4. Catalytic reactor according to any one of the preceding claims in which the cross-sectional area (18) of the reaction zone (5) represents at least 10% of the cross-sectional area of ​​a reactor tube (1), preferably 20%, preferably 50%.

5. Catalytic reactor according to any one of the preceding claims in which the catalyst of the fixed bed is in solid form of granules or powder with a particle size of less than one centimeter, preferably between 200 pm and 5 mm.

6. Catalytic reactor according to the preceding claim in which the porous material (7) has a pore size smaller than the particle size of the catalyst.

7. A catalytic reactor according to any preceding claim wherein the porous material (7) has a pore size configured to allow circulation of the gaseous product.

8. A catalytic reactor according to any preceding claim wherein the inlet (2) and the outlet (3) are arranged respectively at a longitudinal end of the tube (1).

9. Catalytic reactor according to any one of the preceding claims in which the discharge (4) is arranged in the upper part of the tube (1), in a radial direction (9) to the tube.

10. Catalytic reactor according to any one of the preceding claims comprising an inlet plate (10) arranged at the inlet (2) of the tube comprising a first opening (11) arranged opposite the reaction zone (5) so that the liquid reactant enters the tube (1) via the reaction zone (5).

11. Catalytic reactor according to the preceding claim in which the cross-sectional area of ​​the first opening (11) represents 100% of the cross-sectional area (18) of the reaction zone (5).

12. Catalytic reactor according to any one of the preceding claims comprising an outlet plate (12) arranged at the outlet (3) of the tube comprising a second opening (13) arranged opposite the reaction zone (5) so that the liquid product and possibly the unreacted liquid reagent exits the tube (1) via the reaction zone (5).

13. Catalytic reactor according to the preceding claim in which the cross-sectional area of ​​the second opening (13) represents 100% of the cross-sectional area (18) of the reaction zone (5).

14. A catalytic reactor according to any preceding claim comprising a porous plug (15) arranged in the reactor tube (1) at the outlet (3) for maintaining the fixed bed of catalyst in the reaction zone (5) and for allowing the exit of the liquid product and possibly actually the unreacted liquid reagent.

15. A catalytic reactor according to any preceding claim comprising retention elements (14) arranged in contact with the porous material (7) in the circulation zone (6) and having an inclination with the porous material (7) so as to capture the liquid reactant or the liquid product passing through the porous material (7) to redirect it towards the reaction zone (5).

16. Reactor system comprising an enclosure (20) extending along a longitudinal axis (32) receiving several catalytic reactors according to any one of the preceding claims, the catalytic reactors are arranged parallel to each other, their longitudinal axis (8) arranged parallel to the longitudinal axis (32) of the enclosure (20), advantageously horizontally.

17. System according to the preceding claim comprising a thermal energy source configured to supply heat to the reaction zone (5).

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