New electrolysis cell and its use in electrolysis or electrochemistry reactions.

Abstract

Membrane-free electrolysis cell and its use in electrolysis and electrochemistry reactions. The present invention relates to a membrane-free electrolysis cell, comprising a solid body (1), at least one supply channel (51, 52) for a material, two injection channels (6, 7) for two electrolyte flows, said solid body (1) comprising a central cavity (2), and a plurality of distribution channels (81, 82, 83) towards the housings of the electrodes (3, 4). The configuration of the cell allows a supply of a material, in particular a reactant, selectively to the anode or to the cathode. Figure 1

Description

Title of the invention: New electrolysis cell and its use in electrolysis or electrochemistry reactions.

[0001] The present invention relates to a membrane-free electrolysis cell and its use in electrolysis reactions.

[0002] Electrolysis is an important technique in the production of various chemical products. One of the major challenges is the separation of reaction products formed at both the cathode and the anode. To achieve this, a range of electrolysers has been developed over time.

[0003] The majority of these electrolysers include a membrane serving as a physical separation between the cathode and the anode.

[0004] However, electrolysers using membranes are expensive and require restrictive maintenance, due to the aging of the membrane.

[0005] To overcome these problems, membrane-free cells have been developed in recent years.

[0006] However, these cells most often require the implementation of a laminar flow in order to prevent the products formed at the cathode from mixing with the products formed at the anode, which would complicate the subsequent purification of the product to be synthesized, and can in certain cases lead to a parasitic reaction between the products formed or safety issues such as the oxygen / hydrogen mixture.

[0007] This laminar flow requires the implementation of specific and restrictive operational conditions, as well as dimensions of the electrolysis cell, in particular of the channels, specific for each reaction. This is particularly true when gas / liquid mixtures are used, making the design of a versatile membrane-free cell with laminar flow very complicated.

[0008] One of the problems with currently available membrane-free cells lies in the need to solubilize the reagents in the electrolyte. This poses a constraint when, for example, said reagents are poorly soluble in said electrolyte, such as carbon dioxide.

[0009] There is therefore a need to develop electrolysis cells (in flow) designed to allow easy operation, without the need for restrictive maintenance, and allowing easy purification of the expected products.

[0010] Application WO 2023 / 037009 A2 describes an electrolysis cell based on the “split” phenomenon, namely that two electrolyte flows facing each other and meeting at the heart of the cell, induces a change in direction of the flows which are directed towards the porous electrodes. The change in direction thus allows the reactants to be conducted to the corresponding electrode. In this cell the reactant is directly brought to the heart of the cell in the central cavity by specific channels oriented towards the electrodes during the flow path generated after the flow encounters. CONTEXT OF THE INVENTION

[0011] One of the aims of the invention is to provide a membrane-free electrolysis cell.

[0012] Another object of the present invention is to provide a cell which can be used in the absence of laminar flow.

[0013] Another object of the invention is a cell making it possible to supply the reagents intended for the cathode or the anode, selectively, in particular mixed with the electrolyte flows as carrier fluid.

[0014] Another object of the invention is a cell usable on an industrial scale in terms of flow rate.

[0015] Another object of the invention is a cell consisting of a succession of plates in series allowing an adaptable and modular device.

[0016] Another object of the invention is a method using the electrolysis cell in chemical reactions, in particular in the reduction of CO2 to CO.

[0017] Another object of the invention is a method in which the association of the electrolyte and the reagent is of the immiscible liquid / liquid or liquid / gas type.

[0018] Another aim of the invention is the use of a cell which can also allow reactions in which the reagent is miscible in the electrolyte such as the electrolysis reaction of water.

[0019] To meet these needs, the inventors have developed an innovative, membrane-free electrolysis cell, designed such that it allows, by controlling the flow of liquid or gas fluids, to ensure: - the circulation of reactants selectively towards the anode or the cathode - and the separation of products from the anode and the cathode

[0020] while operating at flow rates compatible with industrial objectives, for example allowing industrial production ranging from continuous flow rates of 300 g / h to 5 kg / h, or even more.

[0021] A first object of the present invention is a membrane-free electrolysis cell, comprising: • a solid body (1) and • two porous electrodes, an anode (A) and a cathode (C), • two injection channels (6, 7) of two electrolyte flows (El, E2), and • at least one supply channel (5, 51, 52) of at least one reagent (R),

[0022] said solid body (1) comprising: • two electrode housings, upper (3) and lower (4), comprising respec- tively outlet orifices (31, 41), • a central cavity (2) located between said electrode housings, • a plurality of distribution channels (8, 81, 82, 83),

[0023] each distribution channel connecting a part of the central cavity (2) by an opening (811, 821, 831) to a part of the surface of one of the electrode housings by an opening (812, 822, 832),

[0024] the axis of each distribution channel being defined by the straight line segment connecting the center of the opening of the central cavity (811, 821, 831) with the center of the opening on the surface of the electrode (812, 822, 832),

[0025] at least three distribution channels (8) being present for each electrode housing (3, 4), including a central distribution channel (81) and two lateral distribution channels (82, 83),

[0026] in which: • said porous anode (A) and said porous cathode (C) are respectively contained in the upper (3) and lower (4) electrode housings, • the at least one supply channel (5) extends from one of the injection channels (6, 7) through an orifice (511, 521) of diameter W towards the outside of the cell, and is capable of being connected to a supply of reagent (R), • each injection channel (6, 7) extends from the central cavity (2) through an orifice (61, 71) of height H to the outside of the cell, and is capable of being connected to an electrolyte supply, • the central distribution channel (81) of a housing of an electrode is of height Hs, and its axis is perpendicular to the surface of said electrode and extends from the central cavity (2) through an opening (811) of width Wsc to an opening (812) of width Wsce on the surface of the electrode, • each lateral distribution channel (82, 83) of an electrode housing has a height Hs,

[0027] extends from the central cavity through an opening (821, 831) of width Wsl to an opening (822, 832) of width Wsle on the surface of said electrode and

[0028] its axis is perpendicular to said surface of the electrode or has an inclination of an angle a (9), angle between the axis of said distribution channel and its orthogonal projection on the surface of said electrode,

[0029] said at least one supply channel (5) being capable of conducting said at least one reagent (R), gaseous or liquid, and of injecting said reagent (R) in the form of bubbles and / or films through the orifice (51) into the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7),

[0030] the two injection channels (6, 7) being capable of conducting the electrolyte from the outside of the cell towards the central cavity (2) and to introduce two flows of electrolyte through the respective orifices (61, 71) of the injection channels (6, 7),

[0031] said two injection channels (6, 7) and said orifices (61, 71) being positioned so as to allow the two electrolyte flows (E1, E2) to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode,

[0032] said two central distribution channels (81), respectively of the housings (3, 4) of the anode and of the cathode, being suitable for the passage of the separate electrolyte flows (SIA, S2A, SIC, S2C) from the central cavity (2) to the outlet orifices (31, 41) of the housings (3, 4) by crossing respectively the anode (A) and the cathode (C),

[0033] said lateral distribution channels (82, 83) being configured by their arrangement, their dimension and their orientation relative to the surface of the electrode,

[0034] to conduct the bubbles and / or films of the reagent (R) from the openings (821, 831) to the openings (822, 832),

[0035] and depending on the flow rate of the electrolyte flows and that of the reagent, to conduct the bubbles and / or the films of the reagent from the central cavity (2) selectively towards one of the housings (3, 4) containing respectively the anode (A) and the cathode (C).

[0036] The electrolysis cell can be represented diagrammatically in a 3-dimensional orthonormal reference frame whose origin corresponds to the center (i) of the solid body (1), the Y axis corresponding to the axis connecting the center of the orifices (61, 71) of the injection channels, the Z axis corresponding to the axis connecting the center of the outlet orifices (31, 41) of the electrode housings, the X axis being the axis perpendicular to the plane formed by the Y and Z axes.

[0037] Solid body

[0038] The solid body (1) constitutes the heart of the electrolysis cell of the invention in which the electrochemical reactions take place when an electrical voltage is applied between the two electrodes, anode and cathode, housed in the respective housings.

[0039] The solid body (1) comprises: - the electrode housings (3, 4), - the central cavity (2) - distribution channels (8, 81, 82, 83), - and possibly electrical connection means allowing the application of a different potential between the two electrodes using an electrical generator.

[0040] The solid body (1) is a body closed in a fluid-tight manner and comprises:

[0041] - two fluid inlets facing each other corresponding to the orifices (61,71) by which extend respectively the injection channels (6, 7)

[0042] - two fluid outlets facing each other corresponding to the outlet ports (31, 41) electrode housings (3, 4),

[0043] - advantageously the axis connecting the centers of the orifices (61,71) corresponds to the Y axis and the axis connecting the centers of the outlet orifices (31,41) corresponds to the Z axis, the two axes being perpendicular and intersecting at the center (i) of the solid body (1).

[0044] Electrodes

[0045] By "porous electrode" is meant an electrode which has open porosity allowing the passage of the flow(s) of material, reactant or product, gaseous or liquid, in particular in the form of bubbles, if there are any, and of electrolyte, from the inside of the solid body to the outside of the electrolysis cell.

[0046] By "porous anode" and "porous cathode" respectively, is meant an anode or a cathode respectively which has an open porosity allowing the passage of the flow(s) of material, reactant or product, gaseous or liquid, in particular in the form of bubbles, if there are any, and of electrolyte, from the interior of the solid body to the exterior of the electrolysis cell.

[0047] The theoretical porosity Pt of an electrode, anode or cathode, is defined as the ratio of the volume of the pores of the electrode to the total volume of the electrode.

[0048] The injection and supply channels (external to the solid body)

[0049] By "channel" is meant a sealed means allowing the circulation of a fluid, liquid or gaseous, comprising two openings between which the fluid circulates. During the circulation of a fluid, the opening of the channel through which the fluid enters is called the "channel inlet" and the opening through which the fluid leaves, after circulation in the channel, is called the "channel outlet".

[0050] A channel is considered rectilinear when the centers of the sections are aligned and form a segment, a section being a surface area of ​​the channel corresponding to a planar and transverse section of the channel, which is parallel to an opening.

[0051] Thus the axis of a rectilinear channel is defined by the straight line segment connecting the center of the two openings of said channel.

[0052] A channel is said to be of homogeneous section when the area and shape of each of said sections is substantially identical.

[0053] A channel is said to be of homogeneous height when the height of each of said sections is substantially identical.

[0054] A channel is said to be convergent when a fluid flowing through the channel from the opening towards the outlet of said channel passes through successive sections of decreasing height, allowing an increase in the flow rate of said fluid at the outlet of the channel.

[0055] A channel is said to be divergent when a fluid flowing through the channel from the opening towards the outlet of said channel crosses successive sections of increasing height, allowing a reduction in the flow rate of said fluid at the outlet of the channel.

[0056] Advantageously, the ratio between the area of ​​the opening and that of the channel outlet varies from 0.8 to 1.2.

[0057] By “injection channel” is meant a channel intended to bring the flow of electrolyte from outside the cell to the central cavity (2).

[0058] The electrolysis cell of the invention comprises two injection channels (6, 7) which each extend from the central cavity (2) through an orifice (61, 71). These injection channels (6, 7) are supplied by electrolyte circuits.

[0059] The two orifices (61, 71) of the injection channels (6, 7) are positioned in the central cavity (2) so as to allow the two electrolyte flows (E1, E2) transported respectively by the injection channels (6, 7) to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows. Advantageously, the two orifices (61, 71) are positioned opposite each other and allow a frontal collision of the two electrolyte flows.

[0060] Advantageously, in one embodiment, the two injection channels (6, 7) of the cell are of the same dimensions and are rectilinear and of homogeneous section and / or of homogeneous height allowing a constant flow rate of electrolyte from the inlet of the central cavity (2) to the orifice (61, 71).

[0061] Advantageously, in one embodiment, the two injection channels (6, 7) of the cell are converging channels allowing an increase in the flow rate of electrolyte from the inlet to the outlet of the injection channel.

[0062] Advantageously, in one embodiment, the two injection channels (6, 7) of the cell are divergent channels allowing a reduction in the flow rate of electrolyte from the inlet to the outlet of the injection channel.

[0063] By "supply channel" is meant a channel intended to supply the flow of material containing at least one reagent, from outside the cell to an injection channel (6, 7). The supply channel (5) is supplied by a circuit supplying said reagent.

[0064] Advantageously, the outlet orifice (511, 521) of the supply channel towards the corresponding injection channel (6, 7) is located close to the outlet orifice (61, 71) of said injection channel, at a distance making it possible to ensure that the reagent present in the form of bubbles and / or films is mixed with the electrolyte flow (E1, E2) and that said bubbles and / or said films are transported by the electrolyte without modifying the topology of the liquid flow.

[0065] Advantageously, by way of non-limiting example, the distance between the orifices (511, 521) and the orifices (61, 71) is from 2H to 10H, H being the height or the diameter of the orifice (61, 71).

[0066] The range of values ​​“from H to 10 H” includes the following ranges: from 2H to 3H; from 3H to 4H; from 4H to 5H; from 5H to 6H; from 6H to 7H; from 7H to 8H; from 8H to 9H; from 9H at 10 a.m.

[0067] Advantageously, by way of non-limiting example, the distance between the orifices (511, 521) and the orifices (61, 71) is approximately 7.0 mm.

[0068] Advantageously, in one embodiment, said at least one supply channel (51, 52) of the cell is rectilinear and / or of uniform height allowing a constant flow rate of supply of the reagent (R) to the orifice (61, 71).

[0069] Advantageously, in another embodiment, said at least one supply channel (51, 52) of the cell is a convergent or divergent channel.

[0070] The materials that can be supplied by the supply channels (5) are in particular pure or mixed reagents in order to control their concentration. The reagents can be a gas, such as for example CO2, which can in particular be transformed into CO at the cathode, or a liquid that is immiscible in the electrolyte to allow the formation of bubbles and / or films containing said reagent.

[0071] The material supplied by the supply channels comprises at least one reactant but may also comprise a gas or a liquid diluting the reactant, a catalyst and / or a promoter, such as for example iodine salts or Lewis acids.

[0072] The material supplied containing said at least one reagent by said at least one supply channel is in the form of bubbles or a film in the injection channels (6,7).

[0073] For the purposes of the present invention, the term "bubble" means a small closed volume, gaseous or liquid, delimited by a surface of which the entire surface is surrounded by the electrolyte having a composition different from that of the electrolyte. The bubbles generally have an oval, or even spherical, shape, making it possible to establish a diameter of said bubble and an average diameter of a population of bubbles.

[0074] The term “diameter of the bubble” refers to the arithmetic mean of all the diameters of said bubble.

[0075] The term "average diameter" of a population of bubbles refers to the arithmetic mean of all the diameters of said bubbles forming the population of bubbles.

[0076] For the purposes of the present invention, the term "film" means a layer, a strip or a sheet of gaseous or liquid material, having a composition different from that of the electrolyte, separated from the electrolyte by a surface, generally flat. The film can be characterized by a thickness. It is understood that in the present invention, due to the dynamics of the flows, the formation of bubbles and / or films of reagent is dependent on the flow rates introduced into the cell, the nature of the species (surface tension, density) and the regimes of the different flows (laminar or turbulent).

[0077] The term “thickness of a film” refers to the arithmetic mean of all the heights of said film.

[0078] The term "average thickness" of a population of films refers to the arithmetic mean of all the thicknesses of the population of films.

[0079] At least one reagent is present in the bubbles and / or films in at least one injection channel at the end of the injection of the flow of material transported into said at least one supply channel.

[0080] In a reaction implemented in the device of the invention requiring two reagents, said two reagents are advantageously separated respectively in two distinct supply channels.

[0081] Electrode housing

[0082] By "housing" is meant an empty space or a cavity or a recess contained in the solid body (1). The two housings, upper (3) and lower (4) are each open to the outside respectively by outlet orifices (31, 41).

[0083] The outlet orifices (31, 41) allow the outgoing electrolyte flows to pass through and the said flows to be recovered, comprising the products formed at the electrodes. Opposite each outlet orifice (31, 41), openings are present and intended to contain a porous electrode, respectively the anode (A) or the cathode (C) for the upper (3) and lower (4) housings. The housings are positioned in the solid body (1) so that the anode and the cathode are parallel to each other and so that each of the electrodes communicates with the central cavity (2) through the distribution channels (8).

[0084] The housing openings (3) and (4) containing the anode and the cathode can have various shapes, depending on the desired electrode shape.

[0085] The openings of the housings (3) and (4) have in particular a rectangular or square shape, able to accommodate a substantially parallelepiped or cubic electrode, but can also have, for example: • a circular, oval or round shape, capable of accommodating a substantially cylindrical electrode, or • a hexagonal prism shape, capable of accommodating an electrode substantially in the shape of a hexagonal prism.

[0086] Central cavity

[0087] The “central cavity (2)” is a cavity positioned in the middle of the solid body, and whose geometric center is notably located at the geometric center of the solid body (1). The central cavity (2) is used to receive the electrolyte flows from outside the cell.

[0088] The central cavity (2) is located between the housings of the two electrodes. Its function is to allow the two facing electrolyte flows to meet and to allow the generated flows (SIA, S2A, SIC, S2C) to flow after separation of the flows, from the central cavity to the outlets (31, 41) of the solid body (1) by crossing the porous electrodes.

[0089] Advantageously, the central cavity is of regular shape and comprises a center of symmetry (i) corresponding to the center of the solid body (1) through which pass three axes of symmetry X, Y and Z forming an orthogonal reference frame and through which pass three planes of symmetry (Ho), (V) and (T):

[0090] - the plane of symmetry (Ho) containing the X and Y axes, which is parallel to the surfaces electrodes and is perpendicular to the Z axis connecting the centers of the orifices (31,41),

[0091] - the plane of symmetry (V) containing the X and Z axes, which is perpendicular to the surfaces of the electrodes and perpendicular to the Y axis connecting the orifices (61,71),

[0092] - the plane of symmetry (T) containing the Y and Z axes, which is perpendicular to the electrode surfaces and perpendicular to the X axis.

[0093] Advantageously, the central cavity (2) has a regular geometric shape, comprising a center of symmetry. This shape is, for example, but not limited to, a rectangular parallelepiped of height Hc, a cylinder of circular, oval or round section, of height Hc, a prism whose parallel bases are of regular section (hexagon) or a rectilinear channel of diameter Hc.

[0094] Advantageously, the faces of the central cavity (2) exposed to the surfaces of the electrodes are of the same shape and the same dimensions, making it possible to optimize the exchange surfaces.

[0095] Thus for a surface electrode exposed to the central cavity (2) of rectangular shape of length Lo and width La, the central cavity (2) is a rectangular parallelepiped of length La and width La and thickness Hc. Advantageously the surface of the exposed electrode is of square shape, the length Lo being equal to the width La.

[0096] Distribution channels

[0097] The distribution channels are located in the solid body (1) between the central cavity and the electrode housings. They ensure fluid communication between the central cavity (2) and the two electrodes of the cell.

[0098] The role of the distribution channels is to modify the direction of the incident flow of the mixture consisting of the electrolyte and the reagent bubbles, while accelerating it locally.

[0099] The solid body (1) comprises two series of distribution channels (8), a first series of channels in which each of the channels connects the central cavity to the upper housing (3) containing the anode, and a second series of channels in which each of the channels connects the central cavity (2) to the lower housing (4) containing the cathode.

[0100] Each series of channels comprises at least three channels including a central distribution channel (81) and two lateral distribution channels (82, 83).

[0101] For each series, the lateral distribution channels are located on either side of the lateral distribution channel. At least one lateral distribution channel (82) is located between the inlet (61) of the injection channel (6) and the central distribution channel (81) and at least one lateral distribution channel (83) is located between the inlet (71) of the injection channel (7) and the central distribution channel (81).

[0102] Advantageously, each series comprises five distribution channels, including a central distribution channel (81), two lateral distribution channels located between the inlet orifice (61) of the injection channel (6) and the central distribution channel (81) and two lateral distribution channels (83) located between the inlet orifice (71) of the injection channel and the central distribution channel (81). A second lateral distribution channel between the inlet orifice (61, 71) and the central distribution channel (81) makes it possible to recover and convey the reagent bubbles that have not been conveyed by the first distribution channel to the electrode.

[0103] The distribution channels are configured by their shape, in particular by that of their inlet openings (811, 821, 831) and that of their outlet openings on the electrodes (812, 822, 832) to allow the passage of the electrolyte flow carrying the bubbles and / or the films of the reagent. Consequently, said openings are wider than the thickness of the films and / or the size of the reagent bubbles, generated by the injection of the reagent into the electrolyte flow at the orifice (511, 521). Thus, the widths of the inlet (811) and outlet (812) openings of the central channel, respectively Wsc and Wsce, are greater than the size of the reagent bubbles and / or the thickness of the reagent films. Similarly, the widths of the inlet (821,831) and outlet (822,832) openings of the lateral distribution channels, respectively Wsl and Wsle are greater than the size of the bubbles and / or films of the reagent.

[0104] Advantageously, the size of the bubbles and / or the thickness of the films is less than a value of H / 2, H being the height or the average diameter of the orifice (61, 71), preferably the size of the bubbles is less than 3H / 8.

[0105] In a particular embodiment, the size of the bubbles and / or the thickness of the films is less than or equal to 0.75 mm.

[0106] The range “less than or equal to 0.75 mm” includes the ranges: from 0 to 0.05 mm; from 0.05 to 0.10 mm; from 0.10 to 0.15 mm; from 0.15 to 0.20 mm; from 0.20 to 0.25 mm; from 0.25 to 0.30 mm; from 0.30 to 0.35 mm; from 0.35 to 0.40 mm; from 0.40 to 0.45 mm; from 0.45 to 0.50 mm; from 0.50 to 0.55 mm; from 0.55 to 0.60 mm; from 0.60 to 0.65 mm; from 0.65 to 0.70 mm; from 0.70 to 0.75 mm.

[0107] Ideally the size of the bubbles and / or the thickness of the films must be less than H / 2, preferably less than 3H / 8 (i.e. 0.75mm in our case)

[0108] The distribution channels are advantageously rectilinear channels. The axis of a distribution channel is defined by the straight line segment connecting the center of the inlet openings (811, 821, 831) of the central cavity (2) and that of the outlet opening (812, 822, 832) on the surface of the electrode.

[0109] The distribution channels (8, 81, 82, 83) have the same height Hs. The height Hs is defined as the orthogonal projection of the axis of the distribution channel on the Z axis.

[0110] The two central distribution channels (81) of the electrode housings in the solid body (1) are located in the center of the central cavity, each of their axes being aligned with the Z axis in order to allow the evacuation through the outlet orifices (31, 41) of the flows after change of direction (SIA, S2A, SIC, S2C).

[0111] Advantageously in a particular embodiment, the lateral distribution channels (82, 83) are distributed regularly along the path of the electrolyte flow transporting the bubbles and / or the films of the reagent, in order to allow said bubbles and / or said films of reagent to be conducted towards one of the electrodes.

[0112] "Regularly distributed" means that the centers of the channels are spaced evenly, preferably equidistant from each other.

[0113] Advantageously in another particular embodiment, the lateral distribution channels (82, 83) have different dimensions and / or a variable spacing between the channels in order to increase the exchange surface between the electrodes and the distribution channels.

[0114] The central distribution channel (81) has its axis aligned along Z and is therefore perpendicular to the surface of the electrodes.

[0115] The lateral distribution channels (82, 83)

[0116] are also advantageously perpendicular to the surfaces of the electrodes, thus their axes are parallel to the Z axis,

[0117] either have an inclination of an angle a (9) with the surface of the electrode of the housing to which they are attached.

[0118] The angle a (9) is defined as the angle between the axis of said distribution channel and its orthogonal projection on the surface of said electrode.

[0119] The inclination of the distribution channels is intended to promote the movement of bubbles and / or films towards the electrode during the circulation of electrolyte flows in the central cavity (2).

[0120] The flow in a lateral distribution channel (82) connected to the lower electrode (cathode) housing (4), from the opening (821) to the opening (822), forms an angle a (in absolute value) with the direction of the flow in the central cavity (2) and said channel has a slope of value ( - tan a) relative to the central cavity (2).

[0121] The flow in a lateral distribution channel (82) linked to the upper electrode (anode) housing (3), of the opening (821) forms an angle a (in absolute value) with the direction of the flow in the central cavity (2) and said channel has a rise of value (+ tan a) relative to the central cavity (2).

[0122] Advantageously, the distribution channels (8, 81, 82, 83) are symmetrical with respect to the plane (Ho).

[0123] Advantageously, the distribution channels (8, 81, 82, 83) are symmetrical with respect to the plane (V).

[0124] Advantageously, the distribution channels (8, 81, 82, 83) are symmetrical with respect to the plane (T).

[0125] By "the distribution channels are symmetrical with respect to a plane" is meant that their distribution in the central cavity (2), their arrangement in the solid body (1), their dimension (length, axis, opening) and their orientation are symmetrical with respect to said plane which represents a plane of symmetry.

[0126] Split

[0127] When using the electrolysis cell according to the present invention, the two electrolyte flows (E1, E2), supplied by the two injection channels (6) and (7), meet, frontally, in the central cavity (2). The collision of the two flows then causes a change in direction of said two flows.

[0128] A part of the first flow (SIA) goes towards the anode, while the other part (SIC) goes towards the cathode. Similarly, a part of the second flow (S2A) goes towards the anode, while the other part (S2C) goes towards the cathode. The two parts (SIA, S2A) going towards the anode can, at least partially, mix with each other, just like the two parts (SIC, S2C) going towards the cathode. The general principle of these phenomena has been studied by Stigler et al (The Fluid Flow in the T-Junction. The Comparison of the Numerical Modeling and Piv Measurement, Procedia Engineering 39 (2012) p. 19-27).

[0129] This separation of the two flows (called “Split” in English), accompanied by a change of direction, allows the electrolyte flow to reach the electrodes in a direction substantially perpendicular to the electrodes. This facilitates the passage of said flows through the porous electrodes.

[0130] The flow of fluxes towards the outside of the cell, through the porous electrodes, prevents the electrolysis products from migrating into the central cavity, said electrolysis products being "driven" towards the outside of the cell to be recovered. The flux recovered from the cathode is called the "catholyte", and the flux recovered from the anode is called the "anolyte".

[0131] By "catholyte" is meant the flow of electrolyte after it has passed through the cathode from the inside of the solid body (1) to the outside of the electrolysis cell. It is understood that the catholyte comprises electrolyte, reaction products, and possibly excess reagents and materials, which have not undergone any reaction.

[0132] By "anolyte" is meant the flow of electrolyte after it has passed through the anode from the inside of the solid body (1) to the outside of the electrolysis cell. It is understood that the anolyte includes electrolyte, reaction products, and possibly excess reactants and materials.

[0133] The inventors unexpectedly found that the electrolysis cell according to the present invention, the structure of which is such: - that it allows, by controlling the flows in the cell, a supply of the reagent (R) from the outside of the solid body (1) to the inside of it, in the form of films and / or bubbles mixed with the flow of electrolyte as a transport fluid, and selectively towards one of the electrodes by controlling the flow regime, - and that it causes the creation of a “split” of the electrolyte, making it possible to avoid the mixing of the products formed at the cathode with the products formed at the anode, despite the absence of a membrane, while ensuring the electrical conductivity of the cell.

[0134] Indeed, without being bound by theory, as demonstrated by the simulations and the first tests of validation of the concept carried out by the Inventors, the flow rate of the electrolyte in the injection channel, the flow rate of reagent in the supply channel and the ratio between these two flow rates are at the origin of different flow regimes of the mixture of bubbles and / or films of reagent with the flow of electrolyte which is injected into the solid body of the cell according to the invention. By suitably selecting this ratio and the flow rates it is possible to favor a flow regime such as that in which the inertial effects applied to the bubbles are preponderant over the flotation / gravity effects.

[0135] In this regime dominated by inertial effects, the bubbles and / or reagent films move towards the electrode (cathode) in the lower housing (4) via the distribution channels (8) distributing the lower housing.

[0136] Outside of this regime, the flotation / gravity effects are predominant and the bubbles and / or films of the reagent (less dense than the electrolyte) move towards the electrode (anode) in the upper housing (3) via the distribution channels (8) distributing the upper housing (3).

[0137] The inventors have also unexpectedly found that the electrolysis cell according to the invention operating at industrially usable flow rates, i.e., without limitation, of the order of a few tens of milliliters per minute for the reagent and a few hundred milliliters per minute for the liquid electrolyte, has the advantage of being oriented independently of gravity to allow the transport of bubbles and / or films of the reagent towards one of the electrodes in the targeted case of a regime predominated by inertial effects.

[0138] This is all the more surprising since the flow rate regimes implemented by the device of the invention are outside the technical field of microfluidics, in the sense that the dimensions of the device of the invention are for the most part beyond the millimeter and the flow regimes are well above those which are usually studied in microfluidics.

[0139] In addition, the membrane-free cells of the invention have the following undeniable advantages: - 1. Simplicity: Membrane-free electrolyzers do not require the use of membranes, which simplifies design and reduces system complexity. This can lead to reduced manufacturing and maintenance costs. - 2. Longevity: The membranes used in traditional electrolysers can degrade over time due to chemical reactions and mechanical stress. By eliminating the need for a membrane, membraneless electrolyzers can have a longer lifespan and require less frequent replacement. - 3. Higher efficiency: membrane-free electrolyzers can achieve higher efficiency compared to traditional electrolysers. Without a membrane, there is no electrical resistance caused by the membrane, which leads to better ion transport and reduced energy losses. - 4. Higher current density: membrane-free electrolysers can operate at higher current densities than membrane electrolysers. This means they can produce hydrogen or oxygen gas at a faster rate, increasing the overall productivity of the electrolyser. - 5. Reduced maintenance: the membranes of traditional electrolysers can become clogged or fouled over time, requiring regular cleaning and maintenance. Membrane-free electrolyzers eliminate this problem, reducing maintenance requirements and system downtime. - 6. Flexibility: membrane-free electrolysers can be used with a wider range of electrolytes and concentrations and operating conditions (pressure, temperature) compared to membrane electrolysers. This allows greater flexibility in the electrolysis process and the ability to optimize the system for specific applications. - 7. Scalability: The simplicity and efficiency of membrane-free electrolysers make them easy to scale up or down for different applications. They can be easily integrated into larger systems or used as stand-alone units, depending on user needs. - 8. Environmentally friendly: The elimination of membranes in the Membrane-free electrolyzers reduce the use of materials that can impact the environment. In addition, the higher efficiency of membrane-free electrolyzers results in less energy waste, thus reducing the carbon footprint of the electrolysis process.

[0140] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, said electrolysis cell being in 3D.

[0141] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, said electrolysis cell being in 2D and comprising a central cavity (2) in the form of a channel (21) connecting the orifices (61, 71).

[0142] In the present invention, the term "2D electrolysis cell" means a cell in which all the elements of the cell are included in a single plate or in the assembly of two plates. Thus, two porous electrodes, anode and cathode, the two injection channels (6, 7) and the at least one supply channel (5), the solid body (1) comprising the housings of the electrodes (3, 4), the central cavity (2) and the distribution channels, are contained in a plate or in the assembly of two plates, which may optionally be transparent.

[0143] The 2D cell is characterized by a small dimension along the X axis compared to the two Y and Z axes, namely a thickness of the order of a millimeter along the X axis and several centimeters along the Y and Z axes.

[0144] As an illustrative and non-limiting example, a 2D device consists of a plate or the assembly of two plates, and the device has a length along the Y axis of approximately 11.0 cm, a width along the Z axis of approximately 6.0 cm and a total thickness along the X axis of approximately 10 mm.

[0145] In this device, the membrane-free electrolysis cell according to the invention comprises a total length of the channels along the Y axis of approximately 60 mm, a distance between the outlet openings (31, 41) along the Z axis of approximately 7.0 mm and an average diameter of the channels of approximately 1 mm along the X axis.

[0146] Advantageously, the central cavity (2) in the form of a channel (21) has a height H identical to the height of the orifices (61, 71) and the injection channels.

[0147] In this particular embodiment of the invention, a 2D cell can be used as a prototype cell in order to evaluate the optimal parameters for setting up the desired electrolysis reaction, but also serve as a unitary electrolysis cell for setting up a device comprising several cells.

[0148] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, said electrolysis cell comprising two reagent supply channels (51, 52), respectively connected to the injection channels (6, 7).

[0149] Advantageously, the two supply channels (51, 52) are configured to transport the same reagent, allowing symmetry in terms of flow rates in the flows entering the central cavity (2). For example, the two supply channels (51, 52) are connected by circuits to the same supply source.

[0150] Advantageously, the two supply channels transport different compounds of which at least one of the compounds is the reactant, the other compound possibly being another reactant or an additive or a promoter.

[0151] Advantageously, the two supply channels each transport a different reagent necessary for carrying out the same chemical reaction at one of the electrodes.

[0152] The solid body (1) comprises a center through which pass three orthogonal axes X, Y and Z forming an orthogonal reference frame and through which pass three planes (Ho), (V) and (T):

[0153] - the plane (Ho) containing the X and Y axes, which is parallel to the surfaces of the electrodes and is perpendicular to the Z axis connecting the centers of the orifices (31,41),

[0154] - the plane (V) containing the X and Z axes, which is perpendicular to the surfaces of the electrodes and perpendicular to the Y axis connecting the orifices (61,71),

[0155] - the plane (T) containing the Y and Z axes, which is perpendicular to the surfaces of the electrodes and perpendicular to the X axis.

[0156] The center of symmetry of the central cavity (2) is identical to that of the solid body and the axes X, Y and Z and the planes (Ho), (V) and (T) are identical to those of the central cavity (2). Although the axes X, Y and Z and the planes (Ho), (V) and (T) are respectively axes of symmetry and planes of symmetry of the central cavity (2), they are not necessarily those of the solid body (1), the latter comprising other elements such as the housings and the distribution channels, which may not be symmetrical.

[0157] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid body (1) comprises a plane of symmetry (Ho) parallel to the surfaces of the electrodes, perpendicular to the Z axis connecting the centers of the orifices (31, 41) and passing through the center of said solid body (1).

[0158] In this embodiment, it is understood that there is a planar symmetry between the upper (3) and lower (4) housings.

[0159] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid body (1) comprises a plane of symmetry (V) perpendicular to the surfaces of the electrodes, perpendicular to the Y axis connecting the orifices (61,71) and passing through the center of said solid body (1).

[0160] It is understood in this embodiment that there exists in the solid body (1) a planar symmetry of means for conveying the two electrolyte flows (El, E2) which face each other in the central cavity. In other words, each of the flows (El, E2) has identical flow conditions in the solid body (1) before meeting. in the central cavity (2).

[0161] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid body (1) comprises a plane of symmetry (T) perpendicular to the surfaces of the electrodes, perpendicular to the X axis and passing through the center of said solid body (1).

[0162] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid body (1) comprises:

[0163] - a plane of symmetry (Ho) parallel to the surfaces of the electrodes, perpendicular to the Z axis connecting the centers of the orifices (31, 41) and passing through the center of said solid body (1),

[0164] - and / or a plane of symmetry (V) perpendicular to the surfaces of the electrodes, perpen dicular to the Y axis connecting the orifices (61,71) and passing through the center of said solid body (1),

[0165] - and / or a plane of symmetry (T) perpendicular to the surfaces of the electrodes, perpen dicular to the X axis and passing through the center of said solid body (1).

[0166] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid body (1) comprises a center of symmetry (i).

[0167] In this embodiment, the solid body (1) comprises three planes of symmetry (Ho), (V) and (T).

[0168] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which each electrode housing (3, 4) comprises n lateral distribution channels (82, 83), n being an even number from 2 to 10, in particular n is equal to 4.

[0169] Advantageously n is equal to 2, 4, 6, 8 or 10.

[0170] Multiplying the number of lateral distribution channels (82,83) makes it possible to improve the routing of reagent bubbles to the electrodes and to distribute them more homogeneously on the surface of the electrodes.

[0171] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the central and lateral distribution channels of an electrode housing (8, 81, 82, 83) are symmetrical with respect to the plane (V) and spaced regularly.

[0172] "Regularly spaced" means that the centers of the channels are equidistantly spaced. In the case where the opening of the distribution channels extends over the entire width of the central cavity, the centers of the openings of the distribution channels are aligned equidistant from each other along the length of the central cavity.

[0173] According to a particular embodiment, the present invention relates to a cell electrolysis as defined above, wherein the width Wsl of the openings of the lateral distribution channels at the surface of the cavity (821, 831) is from 1.0 mm to 20.0 mm, greater than the size of the bubbles and / or the thickness of the films comprising the reagent in order to allow the passage and conveyance of said bubbles or said reagent film

[0174] and / or in which the height Hs of the distribution channels (8, 81, 82, 83) is from 0.5 to 5.0 mm

[0175] and / or in which the angle a is from 14° to a value less than or equal to 90°, in particular the axes of the distribution channels (8, 81, 82, 83) are perpendicular to the surface of the electrodes

[0176] and / or wherein the opening of the distribution channels (811, 821, 831) is in the form of an oval or circular or rectangular or square shape.

[0177] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the width Wsl of the openings of the lateral distribution channels at the surface of the cavity (821, 831) is from 1.0 mm to 20.0 mm, and is greater than the size of the bubbles and / or the thickness of the films comprising the reagent in order to allow the passage and conveyance of said reagent bubbles towards the electrodes.

[0178] The range “from 1.0 mm to 20.0 mm” includes the following ranges:

[0179] From 1.0 to 1.5mm, from 1.5 to 2.0mm, from 2.0 to 2.5mm, from 2.5 to 3.0mm, from 3.0 to 3.5mm, 3.5 to 4.0 mm, 4.0 to 4.5 mm, 4.5 to 5.0 mm, 5.0 to 5.5 mm, 5.5 to 6.0 mm, 6.0 to 6.5 mm, 6.5 to 7.0 mm, 7.0 to 7.5 mm, 7.5 to 8.0 mm, 8.0 to 8.5 mm, 8.5 to 9.0 mm, 9.0 to 9.5 mm and 9.5 to 10.0 mm. Then from 10.0 to 11.0 mm, from 11.0 to 12.0 mm, from 12.0 to 13.0 mm, from 13.0 to 14.0 mm, from 14.0 to 15.0 mm, from 15.0 to 16.0 mm, from 16.0 to 17.0 mm, from 17.0 to 18.0 mm, from 18.0 to 19.0 mm and from 19.0 to 20.0 mm.

[0180] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the height Hs of the distribution channels (8, 81, 82, 83) is from 0.5 to 5.0 mm.

[0181] The range of “from 0.5 to 5 mm” includes the following ranges: from 0.5 to 0.6 mm; from 0.6 to 0.7 mm; from 0.7 to 0.8 mm; from 0.8 to 0.9 mm; from 0.9 to 1.0 mm; from 1.0 to 1.1 mm; from 1.1 to 1.2 mm; from 1.2 to 1.3 mm; from 1.3 to 1.4 mm; from 1.4 to 1.5 mm; from 1.5 to 1.6 mm; from 1.6 to 1.7 mm; from 1.7 to 1.8 mm; from 1.8 to 1.9 mm; from 1.9 to 2.0 mm then from 2.0 to 2.5 mm; from 2.5 to 3 mm; from 3.0 to 3.5 mm; from 3.5 to 4.0 mm; from 4.0 to 4.5 mm and from 4.5 to 5.0 mm.

[0182] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the angle a is from 14° to a value less than 90°.

[0183] The range “from 14° to a value less than 90°” includes the following ranges: from 14°C to 20°, from 20 to 25°, from 25 to 30°, from 30 to 35°, from 35 to 40°, from 40 to 45°, from 45 to 50°, from 50 to 55°, from 55 to 60°, from 60 to 65°, from 65 to 70°, from 70 to 75°, from 75 to 80°, from 80 to 85°, from 85 to a value below 90°.

[0184] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the axis of the distribution channels (8, 81, 82, 83) is perpendicular to the surface of the electrodes.

[0185] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the opening of the distribution channels (811, 821, 831) is in the form of an oval or circular or rectangular or square shape.

[0186] Advantageously, the openings of the distribution channels are circular, in particular round, facilitating the flow of the reagent.

[0187] Advantageously, the opening of the distribution channels is rectangular in shape with a length equal to the width of the central cavity and a width greater than the size of the bubbles and / or the reagent films, said rectangular openings being arranged parallel to each other and being perpendicular to the Y axis.

[0188] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the central cavity (2) of the solid body has a height Hc of 1.0 to 6.0 mm,

[0189] and / or in which the central cavity (2) of the solid body is inscribed in a rectangular parallelepiped of width La and length Lo and height Hc, preferably

[0190] the width La being from 2.0 to 100.0 mm

[0191] the length Lo being from 2.0 to 100.0 mm and represents the distance between the orifices (61, 71) of the two injection channels (6, 7).

[0192] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the central cavity (2) of the solid body has a height Hc of 1.0 to 6.0 mm.

[0193] The range “from 1.0 to 6.0 mm” includes the following intervals:

[0194] from 1.0 to 1.2 mm; from 1.2 to 1.4 mm; from 1.4 to 1.6 mm; from 1.6 to 1.8 mm; from 1.8 to 2.0 mm ;

[0195] from 2.0 to 2.2 mm; from 2.2 to 2.4 mm; from 2.4 to 2.6 mm; from 2.6 to 2.8 mm; from 2.8 to 3.0 mm;

[0196] from 3.0 to 3.2 mm; from 3.2 to 3.4 mm; from 3.4 to 3.6 mm; from 3.6 to 3.8 mm; from 3.8 to 4.0 mm;

[0197] from 4.0 to 4.2 mm; from 4.2 to 4.4 mm; from 4.4 to 1.6 mm; from 4.6 to 4.8 mm; from 4.8 to 5.0 mm;

[0198] from 5.0 to 5.2 mm; from 5.2 to 5.4 mm; from 5.4 to 5.6 mm; from 5.6 to 5.8 mm; from 5.8 to 6.0 mm.

[0199] Thus the distance between the two electrodes is defined by the sum of the height of the central cavity Hc, the height of the distribution channels of the anode housing and that of the distribution channels of the cathode housing.

[0200] Advantageously, the heights of the distribution channels of the two housings are identical and equal to Hs. The distance between the electrodes is therefore the sum of Hc and twice the height Hs of the distribution channels (i.e. Hc+2Hs).

[0201] For information, increasing the distance between the electrodes increases the internal electrical resistance of the device, thereby penalizing the overall efficiency. There is therefore advantageously in membrane-free cells an optimal distance between the electrodes, dependent on the configuration of the cell (surface and nature of the electrodes) which can be determined and adjusted to minimize the electrical resistance of the device.

[0202] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the central cavity (2) of the solid body is inscribed in a rectangular parallelepiped of width La and length Lo and height Hc, preferably

[0203] the width La being from 2.0 to 100.0 mm,

[0204] the length Lo being from 2.0 to 100.0 mm and represents the distance between the orifices (61, 71) of the two injection channels (6, 7).

[0205] The range “from 2.0 to 100.0 mm” includes the following ranges of values:

[0206] from 2.0 to 3.0 mm; from 3.0 to 4.0 mm; from 4.0 to 5.0 mm; from 5.0 to 6.0 mm; from 6.0 to 7.0 mm; from 7.0 to 8.0 mm; from 8.0 to 9.0 mm; from 9.0 to 10.0 mm;

[0207] from 10.0 to 15.0 mm; from 15.0 to 20.0 mm; from 20.0 to 25.0 mm; from 25.0 to 30.0 mm; from 30.0 to 35.0 mm; 35.0 to 40.0 mm; 40.0 to 45.0 mm; 45.0 to 50.0 mm;

[0208] from 50.0 to 55.0 mm; from 55.0 to 60.0 mm; from 60.0 to 65.0 mm; from 65.0 to 70.0 mm; from 70.0 to 75.0 mm; 75.0 to 80.0 mm; 80.0 to 85.0 mm; 85.0 to 90.0 mm; 90.0 to 95.0 mm; from 95.0 to 100.0 mm.

[0209] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the width Wsl of the openings of the lateral distribution channels at the surface of the cavity (821, 831) is from La / 20 to La / 5, greater than the size of the bubbles comprising the reagent in order to allow the passage and routing of said bubbles and / or said reagent films towards the electrodes.

[0210] Advantageously, the central cavity (2) is a rectangular parallelepiped with a square base of identical length and width, from 2.0 to 100.0 mm, and of height Hc.

[0211] As a non-limiting example, the side of the square base of the parallelepiped forming the central cavity (2) is approximately 2.25 cm, i.e. a surface area of ​​5.0 cm2, for electrodes (anode and cathode) with a square base of approximately 5 cm2 in surface area and 2.25 cm on a side.

[0212] According to a particular embodiment, the present invention relates to a cell electrolysis as defined above, in which the housings of the electrodes have a shape comprising a portion converging towards the outlet orifices (31, 41).

[0213] In the housing of the electrodes (3, 4), the outlet zone (31, 41) downstream of the electrodes advantageously has a convergent part, that is to say a section decreasing as one approaches the outlet of the solid body (1), so as to limit any recirculation zones which could promote the coalescence of the bubbles. Significant coalescence of the bubbles would have the effect of preventing their exit, or even allowing them to rise into the core of the cell, which would penalize the ohmic resistance of the cell.

[0214] Advantageously, said converging part is inscribed in a pyramid with a rectangular or square base corresponding to the surface of the electrodes and the apex of which comprises the outlet orifice (31, 41) of the electrode housing.

[0215] Advantageously, said converging part is present in the form of a funnel.

[0216] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the height H of the injection channel (6,7) is 1.0 to 6.0 mm, preferably 2.0 mm.

[0217] and / or in which the width W of the supply channel (5,51,52) is 0.5 to 2.5 mm, preferably 0.5 mm.

[0218] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the height H of the injection channel (6,7) is 1.0 to 6.0 mm, preferably 2.0 mm.

[0219] The range “from 1.0 to 6.0 mm” includes the following intervals:

[0220] from 1.0 to 1.1 mm; from 1.1 to 1.2 mm; from 1.2 to 1.3 mm; from 1.3 to 1.4 mm; from 1.4 to 1.5 mm; from 1.5 to 1.6 mm; from 1.6 to 1.7 mm; from 1.7 to 1.8 mm; from 1.8 to 1.9 mm; from 1.9 to 2.0 mm;

[0221] from 2.0 to 2.1 mm; from 2.1 to 2.2 mm; from 2.2 to 2.3 mm; from 2.4 to 2.5 mm; from 2.5 to 2.6 mm; from 2.6 to 2.7 mm; from 2.7 to 2.8 mm; from 2.8 to 2.9 mm; from 2.9 to 3.0 mm;

[0222] from 3.0 to 3.1 mm; from 3.1 to 3.2 mm; from 3.2 to 3.3 mm; from 3.4 to 3.5 mm; from 3.5 to 3.6 mm; from 3.6 to 3.7 mm; from 3.7 to 3.8 mm; from 3.8 to 3.9 mm; from 3.9 to 3.0 mm;

[0223] from 4.0 to 4.1 mm; from 4.1 to 4.2 mm; from 4.2 to 4.3 mm; from 4.4 to 4.5 mm; from 4.5 to 4.6 mm; from 4.6 to 4.7 mm; from 4.7 to 4.8 mm; from 4.8 to 4.9 mm; from 4.9 to 5.0 mm;

[0224] from 5.0 to 5.1 mm; from 5.1 to 5.2 mm; from 5.2 to 5.3 mm; from 5.4 to 5.5 mm; from 5.5 to 5.6 mm; from 5.6 to 5.7 mm; from 5.7 to 5.8 mm; from 5.8 to 5.9 mm; from 5.9 to 6.0 mm.

[0225] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the width W of the supply channel (5, 51, 52) is from 0.5 to 2.5 mm, preferably 0.5 mm.

[0226] The range of "0.5 to 2.5 mm" includes the following ranges of values: 0.5 to 0.6 mm; 0.6 to 0.7 mm; 0.7 to 0.8 mm; 0.8 to 0.9 mm; 0.9 to 1.0 mm; 1.0 to 1.1 mm; 1.1 to 1.2 mm; 1.2 to 1.3 mm; 1.3 to 1.4 mm; 1.4 to 1.5 mm; 1.5 to 1.6 mm; 1.6 to 1.7 mm; 1.7 to 1.8 mm; 1.8 to 1.9 mm; 1.9 to 2.0 mm; 2.0 to 2.1 mm; 2.1 to 2.2 mm; from 2.2 to 2.3 mm and from 2.4 to 2.5 mm.

[0227] The width W is defined as the average diameter of the supply channel (5,51,52).

[0228] The width W makes it possible to determine the area of ​​the section of the supply channel.

[0229] The area of ​​the section of the supply channel makes it possible to define the range of values ​​of the flow rates of the reagent flows accessible in the electrolyte cell.

[0230] Advantageously, the width W is identical to the width of the orifice of the supply channel (511, 521) located at the intersection of the injection channel and the supply channel.

[0231] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the ratio between the surface area of ​​the injection channel (6,7) and the surface area of ​​the orifice of the supply channel (51) is from 4.0 to 15.0

[0232] or in which the ratio between the height H of the injection channel (6,7) and the diameter W of the orifice of the supply channel (51) is from 2.0 to 15.0, preferably 4.0.

[0233] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the ratio between the area of ​​the section of the injection channel (6,7) and the area of ​​the orifice of the supply channel (51) is from 4.0 to 15.0.

[0234] The range “from 4.0 to 15.0” includes the following ranges of values: from 4.0 to 4.5; from 4.5 to 5.0; from 5 to 5.5; from 5.5 to 6.0; from 6.0 to 6.5; from 6.5 to 7.0; from 7.0 to 7.5; from 7.5 to 8.0; from 8.0 to 8.5; from 8.5 to 9.0; from 9.0 to 9.5; from 9.5 to 10.0; from 10.0 to 10.5; from 10.5 to 11.0; from 11.0 to 11.5; from 11.5 to 12.0; from 12.0 to 12.5; from 12.5 to 13.0; from 13.5 to 14.0; from 14.0 to 14.5 and from 14.5 to 15.0.

[0235] The area of ​​the section of the injection channel in order to determine this ratio is defined as the area of ​​a section resulting from a transverse plane section perpendicular to the axis of said channel, preferably close to the orifice of the supply channel (51,52) corresponding upstream of said orifice.

[0236] The cross-sectional area of ​​a channel intended to transport a fluid is equivalent to the hydraulic surface used to calculate the flow of a fluid. Thus, when the channel has a circular cross-section, it is possible to define a hydraulic diameter or a hydraulic radius.

[0237] The area of ​​the section of the injection channel (61, 71) makes it possible to define the range of values ​​of the flow rates of the electrolyte flows accessible in the electrolysis cell.

[0238] Advantageously, the flow rates that can be injected into each of the injection channels (61, 71) of said electrolysis cell of the invention are in a range of values ​​from 120 to 2400 mL / min.

[0239] The value range “from 120 to 2400 mL / min” includes the following value ranges:

[0240] from 120 to 130 mL / min; from 130 to 140 mL / min; from 140 to 150 mL / min; from 150 to 160 mL / min; from 160 to 170 mL / min; from 170 to 180 mL / min; from 180 to 190 mL / min; from 190 to 200 mL / min;

[0241] from 200 to 210 mL / min; from 210 to 220 mL / min; from 220 to 230 mL / min; from 230 to 240 mL / min; from 240 to 250 mL / min; from 250 to 260 mL / min; from 260 to 270 mL / min; from 270 to 280 mL / min; from 280 to 290 mL / min; from 290 to 300 mL / min;

[0242] from 300 to 310 mL / min; from 310 to 320 mL / min; from 320 to 330 mL / min; from 330 to 340 mL / min; from 340 to 350 mL / min; from 350 to 360 mL / min; from 360 to 370 mL / min; from 370 to 380 mL / min; from 380 to 390 mL / min; from 390 to 400 mL / min;

[0243] from 400 to 410 mL / min; from 410 to 420 mL / min; from 420 to 430 mL / min; from 430 to 440 mL / min; from 440 to 450 mL / min; from 450 to 460 mL / min; from 460 to 470 mL / min; from 470 to 480 mL / min; from 480 to 490 mL / min; from 490 to 500 mL / min;

[0244] from 500 to 600 mL / min; from 600 to 700 mL / min; from 700 to 800 mL / min; from 800 to 900 mL / min; from 900 to 1000 mL / min;

[0245] from 1,000 to 1,100 mL / min; from 1,100 to 1,200 mL / min; from 1,200 to 1,300 mL / min; from 1300 to 1400 mL / min; 1400 to 1500 mL / min;

[0246] from 1,500 to 1,600 mL / min; from 1,600 to 1,700 mL / min; from 1,700 to 1,800 mL / min; from 1800 to 1900 mL / min; 1900 to 2000 mL / min;

[0247] from 2,000 to 2,100 mL / min; from 2,100 to 2,200 mL / min; from 2,200 to 2,300 mL / min; from 2,300 to 2,400 mL / min.

[0248] The area of ​​the orifice of the supply channel makes it possible to define the range of values ​​of the flow rates of the reagent flow injected into the electrolyte and consequently to control the size of generated reagent bubbles and their speed.

[0249] Advantageously, the flow rates that can be injected into said supply channel (51, 52) of said electrolysis cell of the invention are in a range of values ​​from 5 to 200 mL / min.

[0250] The value range “from 5 to 200 mL / min” includes the following value ranges: from 5 to 6 mL / min; from 6 to 7 mL / min; from 7 to 8 mL / min; from 8 to 9 mL / min; from 9 to 10 mL / min;

[0251] from 11 to 12 mL / min; from 12 to 13 mL / min; from 13 to 14 mL / min; from 14 to 15 mL / min; from 15 to 16 mL / min; from 16 to 17 mL / min; from 17 to 18 mL / min; from 18 to 19 mL / min; from 19 to 20 mL / min;

[0252] from 20 to 25 mL / min; from 25 to 30 mL / min; from 30 to 35 mL / min; from 35 to 40 mL / min; from 40 to 45 mL / min; from 45 to 50 mL / min;

[0253] from 50 to 60 mL / min; from 60 to 70 mL / min; from 70 to 80 mL / min; from 80 to 90 mL / min; from 90 to 100 mL / min;

[0254] from 100 to 110 mL / min; from 110 to 120 mL / min; from 120 to 130 mL / min; from 130 to 140 mL / min; from 140 to 150 mL / min; from 150 to 160 mL / min; from 160 to 170 mL / min; from 170 to 180 mL / min; from 180 to 190 mL / min; from 190 to 200 mL / min;

[0255] The ratio between the area of ​​the section of the injection channel and the area of ​​the orifice of the supply channel makes it possible to define the flow rates of the electrolyte flows and the characteristics of the flow of bubbles and / or films generated from the reagent (size of the bubbles, flow rate of the bubbles, thickness of the films, volume of the films, width of the films), which are accessible by said electrolysis cell.

[0256] Without being bound by theory, the ratio between the area of ​​the section of the injection channel and the area of ​​the orifice of the supply channel is a characteristic which has the effect of determining the competition between the inertial, viscosity and surface tension forces applied to the interface between the two fluids, namely between the electrolyte and the reactant in the form of bubbles and / or films.

[0257] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the ratio between the height H of the injection channel (6,7) and the diameter W of the orifice of the supply channel (51) is from 2.0 to 15.0, preferably 4.0.

[0258] The range “from 2.0 to 15.0” includes the following ranges of values: from 2.0 to 2.5; from 2.5 to 3.0; from 3.0 to 3.5; from 3.5 to 4.0; from 4.0 to 4.5; from 4.5 to 5.0; from 5.5 to 5.5; from 5.5 to 6.0; from 6.0 to 6.5; from 6.5 to 7.0; from 7.0 to 7.5; from 7.5 to 8.0; from 8.0 to 8.5; from 8.5 to 9.0; from 9.0 to 9.5; from 9.5 to 10.0; from 10.0 to 10.5; from 10.5 to 11.0; from 11.0 to 11.5; from 11.5 to 12.0; from 12.0 to 12.5; from 12.5 to 13.0; from 13.5 to 14.0; from 14.0 to 14.5 and from 14.5 to 15.0.

[0259] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porous anode (A) has a theoretical porosity Pt, defined as the ratio of the volume of the pores of the anode to the total volume of the anode, less than 80%, in particular from 25 to 80%, in particular approximately 70%.

[0260] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porous cathode (C) has a theoretical porosity Pt, defined as the ratio of the volume of the pores of the cathode to the total volume of the cathode, less than 80%, in particular from 25 to 80%, in particular about 70%.

[0261] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porous cathode and / or anode have a theoretical porosity Pt, defined as the ratio of the volume of the pores of the electrode to the total volume of the electrode, less than 80%, in particular from 25 to 80%, in particular approximately 70%.

[0262] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porous cathode and anode have a theoretical porosity Pt, defined as the ratio of the volume of the pores of the electrode to the total volume of the electrode, less than 80%, in particular from 25 to 80%, in particular about 70%.

[0263] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porous cathode or anode has a theoretical porosity Pt, defined as the ratio of the volume of the pores of the electrode to the total volume of the electrode, less than 80%, in particular from 25 to 80%, in particular about 70%.

[0264] The range “from 25 to 80%” includes the following intervals:

[0265] from 25 to 30%, from 30 to 35%, from 35 to 40%, from 40 to 45%, from 45 to 50%, from 50 to 55%, from 55 to 60%, 60 to 65%, 65 to 70%, 70 to 75%,

[0266] from 25 to 26%, from 26 to 27%, from 27 to 28%, from 28 to 29%, from 29 to 30%,

[0267] from 30 to 31%, from 31 to 32%, from 32 to 33%, from 33 to 34%, from 34 to 35%, from 35 to 36%, from 36 to 37%, 37 to 38%, 38 to 39%, 39 to 40%,

[0268] from 40 to 41%, from 41 to 42%, from 42 to 43%, from 43 to 44%, from 44 to 45%, from 45 to 46%, from 46 to 47%, 47 to 48%, 48 to 49%, 49 to 50%,

[0269] from 50 to 51%, from 51 to 52%, from 52 to 53%, from 53 to 54%, from 54 to 55%, from 55 to 56%, from 56 to 57%, 57 to 58%, 58 to 59%, 59 to 60%,

[0270] from 60 to 61%, from 61 to 62%, from 62 to 63%, from 63 to 64%, from 64 to 65%, from 65 to 66%, from 66 to 67%, 67 to 68%, 68 to 69%, 69 to 70%,

[0271] from 70 to 71%, from 71 to 72%, from 72 to 73%, from 73 to 74%, from 74 to 75%, from 75 to 76%, from 76 to 77%, 77 to 78%, 78 to 79%, 79 to 80%.

[0272] The theoretical porosity of the electrodes can be evaluated using density calculations, by determining the density ratio between the theoretical density of the non-porous (pore-free) electrode and that of the porous electrode.

[0273] Thus the theoretical porosity of the electrodes can be evaluated using mass calculations, by determining for a given volume, the ratio between the theoretical mass of the non-porous electrode and the mass of the porous electrode.

[0274] The theoretical density of the non-porous electrode is defined as the theoretical mass of a non-porous electrode over the volume of said electrode.

[0275] The theoretical mass of the non-porous electrode is defined as the sum of the masses of each of the elements which compose it, i.e. possibly including the mass of the catalysts present on the surface of the electrodes.

[0276] More precisely, there are mercury porosimeters which allow the porosity (and other parameters such as tortuosity, average pore diameters, etc.) of materials to be measured precisely. In addition, this type of tool coupled with measurements optical (cf. Chen et al., 2022, Determination of the porosity and its heterogeneity of fuel cell microporous layers by X-ray tomography microscopy) allows an estimate of the porosity of each layer constituting the electrodes.

[0277] The porosity of the electrodes contributes to the operation of the present electrolysis cell of the invention. Indeed, the inventors have discovered that the porous electrodes induce a form of blocking which improves the distribution of flow speeds and therefore the general topology of the flow in the electrolysis cell of the invention, as illustrated by example 2 and [Fig. 3]. By limiting the flow speed, the porous electrodes make it possible to homogenize the speed distributions over the entire surface where without an electrode the bulk is concentrated around the meeting point of the two liquid flows. This therefore makes it possible to limit parasitic phenomena such as vortices and recirculation zones, which prevent the transport of reagent bubbles to the lower zone of the cell, namely to the lower housing, and at the same time promote mixing.

[0278] Advantageously, the maximum porosity rate is approximately 80%, because above this value the blockage does not sufficiently modify the flow.

[0279] Advantageously, the minimum porosity rate is approximately 25%, because below this value the electrodes can disturb the outgoing material flows and induce excessive blockage, also promoting parasitic phenomena.

[0280] Advantageously, the optimal porosity rate is approximately 70%, this value makes it possible to influence the blocking of flows by promoting the distribution of flow speeds, without disturbing the outgoing material flows and by limiting parasitic phenomena.

[0281] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the difference in porosity δ between the cathode and the anode is less than 5.0%, said difference is from 0.0 to 5.0%, preferably less than 1.0%.

[0282] The porosity difference ô is defined as the absolute value of the difference between the porosity of the anode and that of the cathode.

[0283] The range “0.0 to 5.0%” includes the following ranges of values:

[0284] from 0.0 to 1.0%, from 1.0 to 2.0%, from 2.0 to 3.0%, from 3.0 to 4.0%, from 4.0 to 5.0%.

[0285] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the difference in porosity δ between the cathode and the anode is less than or equal to 5.0%, preferably from 0.0 to 5.0%, preferably less than or equal to 1.0%.

[0286] The theoretical porosity difference ô is defined as the absolute value of the difference between the theoretical porosity of the anode and that of the cathode.

[0287] Advantageously, the theoretical porosity difference ô is identical to the difference of measured porosity which varies from 0.0 to 5.0%.

[0288] The actual porosity (pore sizes and volumes) can be evaluated by methods known to those skilled in the art, such as a porosimeter or the techniques cited above.

[0289] The small difference in porosity, from 0.0 to 1.0%, between the electrodes, makes it possible to ensure the balancing of the blockages applied to the flows going towards the anode and the cathode. The small difference in porosity makes it possible to ensure a homogeneous distribution between the mixture of fluids going to the anode and the cathode.

[0290] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the porosity of the cathode and that of the anode are identical.

[0291] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the theoretical porosity of the cathode and that of the anode are identical.

[0292] The inventors also unexpectedly noticed that if one of the porous electrodes offers less resistance, most of the flow mixing is directed towards this electrode.

[0293] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the difference in porosity δ between the cathode and the anode is from 5.0 to 20.0%, preferably from 5.0 to 15.0%, preferentially from 5.0 to 10.0%.

[0294] The range “from 5.0 to 20.0%” includes the following ranges of values:

[0295] from 5.0 to 6.0%, from 6.0 to 7.0%, from 7.0 to 8.0%, from 8.0 to 9.0%, from 9.0 to 10.0%, from 10.0 to 11.0%, from 11.0 to 12.0%, from 12.0 to 13.0%, from 13.0 to 14.0%, from 14.0 to 15.0%, from 15.0 to 16.0%, from 16.0 to 17.0%, from 17.0 to 18.0%, from 18.0 to 19.0%, from 19.0 to 20.0%.

[0296] Advantageously, a difference in porosity between the anode and the cathode makes it possible to promote the flow of fluxes towards one of the electrodes.

[0297] Advantageously, a difference in porosity between the electrodes can be counterbalanced by modifying the flow rates in the device.

[0298] Advantageously, a difference in porosity induced during use of the electrolysis cell according to the invention can be counterbalanced by the flexibility of the flow rates that can be introduced into the cell. A difference in porosity induced during use can, for example, come from detachment of the catalyst or from the presence of salts deposited in the pores.

[0299] Thus, in the electrolysis cell according to the invention, a difference in porosity is not a restrictive characteristic. Due to the flexibility in controlling the flow rates, the cell according to the invention makes it possible to overcome a difference in porosity between the two electrodes, making it possible to obtain a robust device.

[0300] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the axis of said supply channel (51, 52) is perpendicular to the axis of said injection channel to which said supply channel is connected.

[0301] Control of the formation of bubbles and / or reagent films is particularly favored by an inlet of the reagent flow perpendicular to the electrolyte flows.

[0302] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, comprising two supply channels (51, 52), in which the axis of each supply channel (51, 52) is perpendicular to the axis of said injection channel to which said supply channel is connected (6, 7).

[0303] Advantageously, the two axes of the two supply channels (51, 52) are located on the same side relative to the plane (Ho) of the solid body. This makes it possible to limit an asymmetry of the constraints on the bubbles and / or the films of reagents in the case of a flow regime controlled by the effects of gravity or flotation.

[0304] Advantageously, the two axes of the two supply channels (51, 52) are located on the same side relative to the plane (Ho) of the solid body and said electrolysis cell is arranged so that its plane (Ho) is perpendicular to the force of gravity.

[0305] Advantageously, the two axes of the two supply channels (51, 52) are located on the same side relative to the plane (Ho) of the solid body and said electrolysis cell is arranged so that: - its plane (Ho) is perpendicular to the force of gravity, and - the axes of the supply channels are located on the side of the lower housing (4).

[0306] Thus, the supply channels transport material flows which have a direction opposite to that of the force of gravity.

[0307] Advantageously, the two axes of the two supply channels (51, 52) are located on the same side relative to the plane (Ho) of the solid body and said electrolysis cell is arranged so that: - its plane (Ho) is perpendicular to the force of gravity, and - the axes of the supply channels are located on the side of the upper housing (3).

[0308] Thus, the supply channels transport material flows which have a direction parallel to that of the force of gravity.

[0309] These embodiments make it possible to orient the cell of the invention in order to control or limit the gravity or flotation constraints applied to the reactant bubbles, in particular in the flow regime controlled by the effects of gravity or flotation.

[0310] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, comprising: • a solid body (1) and two porous electrodes, an anode (A) and a cathode (C), two injection channels (6, 7) of two electrolyte flows (El, E2), and two supply channels (51, 52) of a reagent (R),

[0311] said solid body (1) comprising: two electrode housings, upper (3) and lower (4), respectively comprising outlet orifices (31, 41), a central cavity (2) located between said electrode housings and which is inscribed in a rectangular parallelepiped of height Hc, length Loi and width Lal, of faces (a, b, c, d, e, f),

[0312] the faces (e) and (f) being the upper and lower faces of dimensions Loi and Lal,

[0313] the faces (a) and (b) being parallel to each other and of dimensions Lal and Hc,

[0314] the faces (c) and (d) being parallel to each other and of dimensions Loi and Hc, a center of symmetry (I) through which passes a plane of symmetry (Ho) parallel to the faces (e, f), a plane of symmetry (V) parallel to the faces (a, b) and a plane of symmetry (T) parallel to the faces (c, d); ten distribution channels including five distribution channels (84, 85, 86, 87, 88) by electrode housing,

[0315] each distribution channel has the shape of a rectangular parallelepiped of height Hs, length Lo2 and width Ws, the length Lo2 being identical to the width Lal of the central cavity,

[0316] each distribution channel connects a part of the central cavity (2) by an opening (841, 851, 861, 871, 881) of rectangular shape of length Lo2 and width Ws, to a part of the surface of one of the electrode housings by an opening (842, 852, 862, 872, 882) of the same shape and dimensions as said opening (841, 851, 861, 871, 881),

[0317] so that the five distribution channels (84, 85, 86, 87, 88) per electrode housing are parallel along their length Lo2 and preferably spaced regularly along the length Loi of the cavity, the orifices (61, 71) of the injection channels (6, 7) are positioned facing each other respectively in the center of the faces (a) and (b) on the plane (T) possibly means for orienting (10) the electrolyte flows on the faces (a, b) in the form of a funnel extending from an orifice (61, 71) towards the faces (c) and (d) and positioned in front of the opening of a distribution channel, for a homogeneous distribution of the electrolyte flow between the faces (c) and (d),

[0318] in which: said porous anode (A) and said porous cathode (C) are respectively contained in the upper (3) and lower (4) electrode housings, • each injection channel (6, 7) is along the axis (Y) corresponding to the intersection of the planes (Ho) and (T) and connects the central cavity (2) by an orifice (61, 71) to an electrolyte reservoir (111, 112) supplied by an electrolyte inlet (121, 122), • each supply channel (51, 52) extends from an injection channel (6, 7) through an orifice (512, 521) of diameter W to a reservoir (131, 132) of reagent supplied by a reagent inlet (141, 142), • the centers of the orifices (512, 521) of the supply channels (51, 52), the axes of the injection channels (6, 7) and the centers of the orifices (61, 71) of the injection channels (6, 7) are contained in the plane of symmetry (T),

[0319] the two supply channels (51, 52) being capable of conducting at least one reactant (R), gaseous or liquid, and of injecting said reactant (R) in the form of bubbles and / or in the form of films through the orifice (511, 521) into the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reactant with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7),

[0320] the two injection channels (6, 7) being capable of conducting the electrolyte to from outside the cell to the central cavity (2) and introducing two electrolyte flows through the respective orifices (61, 71) of the injection channels (6, 7),

[0321] said two injection channels (6, 7) and said orifices (61,71) being positioned so as to allow the two electrolyte flows (E1, E2) to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode, the two injection channels (6, 7) being capable of conducting the electrolyte from outside the cell towards the central cavity (2) and of introducing two electrolyte flows through the respective orifices (61, 71) of the injection channels (6, 7),

[0322] the distribution channels (86) being capable of passing the separate electrolyte flows (SIA, S2A, SIC, S2C) from the central cavity (2) to the outlet orifices (31,41) of the housings (3,4) passing respectively through the anode (A) and the cathode (C),

[0323] the distribution channels (84, 85, 86, 87, 88) being configured to conduct the bubbles and / or the films of the reagent (R) from the openings (841, 851, 861, 871, 881) to the openings (842, 852, 862, 872, 882), ,

[0324] and depending on the flow rate of the electrolyte flows and that of the reagent, to conduct the bubbles and / or the reagent films from the central cavity (2) selectively towards one of the housings (3, 4) containing respectively the anode (A) and the cathode (C).

[0325] In a preferred embodiment, the axis of each distribution channel is in the plane of symmetry (T) and is perpendicular to the surface of the electrodes, the axis of the distribution channel central distribution (86) is aligned with the center of symmetry (i) of the solid body (1).

[0326] In a preferred embodiment, the five centers of the five openings of the distribution channels (841, 851, 861, 871, 881) of the upper housing are aligned along an axis located on the face (e) parallel to the Y axis and they are distributed equidistant from each other. Thus said openings (841, 851, 861, 871, 881) are parallel along their length Lo2 which is perpendicular to the length Loi of the central cavity, making it possible to cover an optimal accessible surface of the face (e).

[0327] Consequently, the five centers of the five openings of the distribution channels (842, 852, 862, 872, 882) of the upper housing are aligned along an axis located on the surface of the electrode (anode), parallel to the Y axis and they are distributed equidistant from each other. Thus said openings (842, 852, 862, 872, 882) are parallel along their length Lo2 which is perpendicular to the length Loi of the central cavity making it possible to cover an optimal accessible surface of the surface of the electrode (anode).

[0328] Symmetrically, the five centers of the five openings of the distribution channels (841, 851, 861, 871, 881) of the lower housing are aligned along an axis located on the face (f) parallel to the Y axis and they are distributed equidistant from each other. Thus said openings (841, 851, 861, 871, 881) are parallel along their length Lo2 which is perpendicular to the length Loi of the central cavity making it possible to cover an optimal accessible surface of the face (f).

[0329] The five centers of the five openings of the distribution channels (842, 852, 862, 872, 882) of the lower housing are aligned along an axis located on the surface of the electrode (cathode) parallel to the Y axis and they are distributed equidistant from each other. Thus said openings (842, 852, 862, 872, 882) are parallel along their length Lo2 which is perpendicular to the length Loi of the central cavity making it possible to cover an optimal accessible surface of the surface of the electrode (cathode).

[0330] This embodiment with rectangular openings extending over the entire width La2 of the central cavity (2) allows optimization of the exchange surface between the electrodes and the cavity while ensuring mechanical stability, the interface between the channels allowing the electrodes to be held in place.

[0331] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which the solid body (1), the injection channels (6, 7), the supply channels (51, 52), the electrolyte reservoirs (111, 112) and the reagent reservoirs (131, 132) are included in the same solid matrix (M).

[0332] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid matrix (M) comprises or consists of an assembly of successively stacked plates.

[0333] According to a particular embodiment, the present invention relates to a cell electrolysis as defined above, in which said solid matrix (M) comprises or consists of: - at least one central plate or a set of central plates, said set being in particular made up of two central plates, - two current collector plates each comprising a central opening on which the porous anode and cathode electrodes are mounted respectively - two end plates configured to enclose the plate assembly and respectively comprising the outlets (31, 41), - sealing plates located between two plates of said central plates, said current collector plates and said end plates, - clamping means (15), - two electrolyte flow inlets (121, 122), - two reagent flow inlets (141,142),

[0334] in which

[0335] said at least one central plate is configured to comprise: - the injection channels (6, 7) and the electrolyte reservoirs (111,112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83),

[0336] or the central plates of said assembly are configured so as to comprise, by assembling said central plates of said assembly and sealing plates between said central plates of said assembly: - the injection channels (6, 7) and the electrolyte reservoirs (111,112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83).

[0337] According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid matrix (M) consists of an assembly of plates, stacked successively, comprising: - central plates, - two current collector plates each comprising a central opening on which the porous anode and cathode electrodes are respectively mounted - two end plates configured to enclose the plate assembly and respectively comprising the outlets (31, 41), - sealing plates located between said central plates, said current collector plates and said end plates,

[0338]

[0339]

[0340]

[0341]

[0342]

[0343]

[0344] - clamping means (15), - two electrolyte flow inlets (121, 122) - two reagent flow inlets (141,142) in which the central plates are configured so as to comprise, by assembling said central plates and sealing plates between said central plates,: - the injection channels (6, 7) and the electrolyte reservoirs (111, 112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83). According to a particular embodiment, the present invention relates to an electrolysis cell as defined above, in which said solid matrix (M) consists of an assembly of plates, stacked successively, comprising in particular 11 plates (P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11) comprising: - two central plates P5 and P7, - two current collector plates P3 and P9 each comprising a central opening on which the porous anode and cathode electrodes are respectively mounted - two terminal plates PI and PI 1 configured to enclose the plate assembly and respectively comprising the outputs (31, 41), - six sealing plates P2, P4, P6, P8 and P10 located between each of said plates (PI, P3, P5, P7, P9, PI 1), P6 being located between P5 and P7, P4 and P8 being respectively adjacent to P5 and P7, P2 and P10 being located respectively between PI and P3 and between P9 and PI 1, - clamping means (15), - two electrolyte flow inlets (121, 122) - two reagent flow inlets (141,142) in which the central plates P5 and P7 are configured so as to comprise, by assembling the plates P5, P6 and P7: - the injection channels (6, 7) and the electrolyte reservoirs (111,112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83). Advantageously, the P5 and P7 plates are made of PTFE, PVC or polymerizable resin. Advantageously, P5 and P7 plates are obtained by machining or rapid prototyping such as 3D printing or stereolithography.

[0345] Advantageously, the sealing plates P2, P4, P6, P8 and P10 are made of EPDM (Ethylene-Propylene-Diene Monomer) rubber vulcanized with peroxide.

[0346] Advantageously, the sealing plates P2, P4, P6, P8 and P10 are prepared by laser cutting.

[0347] Advantageously, the plates PI and PI 1 are made of metal, in particular chosen from stainless steel, aluminum and titanium, or of plastic, in particular chosen from polyetheretherketone, also called PEEK (PolyEtherEtherKetone) and polymethyl methacrylate (PMMA).

[0348] Advantageously, the plates PI and PI 1 are obtained by machining or cutting by water jet.

[0349] Advantageously, the current collector plate of the anode P3 is made of stainless steel or platinum-coated titanium.

[0350] Advantageously, the current collector plate of the anode P3 is obtained by machining or by water jet cutting.

[0351] Advantageously, the current collector plate of the cathode P9 is made of titanium, in particular platinum-coated titanium.

[0352] Advantageously, the current collector plate of the cathode P9 is obtained by machining or by water jet cutting.

[0353] Advantageously, the clamping means comprise holes at the periphery of said plates into which screws / bolts, metal or PTFE washers and suitable nuts can be inserted.

[0354] According to another embodiment, the invention relates to an electrolysis cell without membrane and without central channels (81).

[0355] According to a particular embodiment, the present invention relates to a membrane-free electrolysis cell, comprising: • a solid body (1) and • two porous electrodes, an anode (A) and a cathode (C), • two injection channels (6, 7) of two electrolyte flows (El, E2), and • at least one supply channel (5, 51, 52) of at least one reagent (R),

[0356] said solid body (1) comprising: • two electrode housings, upper (3) and lower (4), respectively comprising outlet orifices (31, 41), • a central cavity (2) located between said electrode housings, • a plurality of lateral distribution channels (82, 83),

[0357] each distribution channel connecting a part of the central cavity (2) by an opening (821, 831) to a part of the surface of one of the electrode housings by an opening (822, 832),

[0358] the axis of each distribution channel being defined by the straight line segment connecting the center of the opening of the central cavity (821,831) with the center of the opening on the surface of the electrode (822,832),

[0359] at least two lateral distribution channels (82,83) being present for each electrode housing (3,4),

[0360] in which: • said porous anode (A) and said porous cathode (C) are respectively contained in the upper (3) and lower (4) electrode housings, • the at least one supply channel (5) extends from one of the injection channels (6, 7) through an orifice (511, 521) of diameter W towards the outside of the cell, and is capable of being connected to a supply of reagent (R), • each injection channel (6, 7) extends from the central cavity (2) through an orifice (61, 71) of height H to the outside of the cell, and is capable of being connected to an electrolyte supply, • each lateral distribution channel (82, 83) of an electrode housing has a height Hs,

[0361] extends from the central cavity through an opening (821, 831) of width Wsl to an opening (822, 832) of width Wsle on the surface of said electrode and

[0362] its axis is perpendicular to said surface of the electrode or has an inclination of an angle a (9), angle between the axis of said distribution channel and its orthogonal projection on the surface of said electrode,

[0363] said at least one supply channel (5) being capable of conducting a reagent (R), gaseous or liquid, and of injecting said reagent (R) in the form of bubbles and / or in the form of films through the orifice (51) into the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7),

[0364] the two injection channels (6, 7) being capable of conducting the electrolyte from outside the cell towards the central cavity (2) and of introducing two flows of electrolyte through the respective orifices (61, 71) of the injection channels (6, 7),

[0365] said two injection channels (6, 7) and said orifices (61, 71) being positioned so as to allow the two electrolyte flows (E1, E2) to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode through the lateral distribution channels (82, 83) of the upper electrode housing (3), and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode through the lateral distribution channels (82, 83) of the lower electrode housing (4),

[0366] said lateral distribution channels (82, 83) being also configured by their dis- position, their size and their orientation relative to the surface of the electrode,

[0367] to conduct the bubbles and / or the films of the reagent (R) from the openings (821, 831) towards the openings (822, 832),

[0368] and depending on the flow rate of the electrolyte flows and that of the reagent, to conduct the bubbles and / or the reagent films from the central cavity (2) selectively towards one of the housings (3, 4) containing respectively the anode (A) and the cathode (C).

[0369] This variant of an embodiment of the device according to the invention is characterized by an absence of central channels (81) intended for the routing of the separate flows (SIA, S2A, SIC, S2C) directly to the porous electrodes. These separate flows (SIA, S2A, SIC, S2C) are thus constrained by the configuration of the cell to be routed towards the lateral distribution channels (82, 83) to pass through their respective electrode in order to exit the cell through the respective outlet orifices (31, 41). However, this variant of the cell according to the invention remains functional and allows selective routing of a reagent to one of the electrodes.

[0370] According to a particular embodiment, the invention relates to an electrolysis cell as defined above, further comprising removable means for closing off said supply channel (5) and / or means for connecting the opening of said supply channel (5) to the electrolyte supply distributing said injection channels (6, 7).

[0371] This embodiment makes it possible to obtain a modular electrolysis cell, which can be adapted for selective delivery of a reactant to one of the electrodes or for use as an electrolysis cell implementing separation of the products generated by the anode and the cathode by controlling the volume flow rates of injection of the electrolyte in a reaction in which the reactants are miscible in the electrolyte, such as the hydrolysis of water into oxygen and hydrogen.

[0372] According to a particular embodiment, the invention relates to an electrolysis cell as defined above, in which said injection channels (6, 7) extending from the electrolyte inlet orifice (121, 121) to the inlet orifice (61, 71) of the central cavity are rectilinear channels, preferably of convergent diameter.

[0373] According to a particular embodiment, the invention relates to an electrolysis cell as defined above, in which said cell comprises roughness elements in the central cavity (2), preferably in the form of appendages, preferably between the orifices (61,71) and the openings of the distribution channels.

[0374] Advantageously, the roughness elements are configured to homogenize the flow of electrolyte and / or promote the movement of the reagent preferentially towards one of the two electrodes.

[0375] These appendages can take the form of cylinders, rectangular or square parallelepipeds or blades.

[0376] Another object of the present invention relates to the use of an electrolysis cell of the invention as defined above in an electrochemical reaction.

[0377] Without limitation, the electrochemical reactions targeted are in particular oxidation-reduction reactions, preferably the reaction of reduction of CO2 to CO, of carbonylation by CO, of hydrogenation by H2 or of dehydrogenation and oxidation of alcohols.

[0378] The electrolysis cell according to the present invention can be used both to carry out cathodic reactions and to carry out anodic reactions, said cathodic and anodic reactions being able to take place simultaneously.

[0379] Among the cathodic reactions taking place at the cathode, we can cite, for example: • the reduction of carbon dioxide (CO2) to carbon monoxide (CO), formic acid (CO2H), methanol (CH3OH), methane (CH4), ethylene (C2H2) • the reduction of alkyl oxalate or oxamide, ester or amide, in particular to ethylene glycol, • the production of Syngas (mixture of CO and H2 in certain proportions) • the reduction of nitrogen into ammonia.

[0380] Among the anodic reactions taking place at the anode, we can cite, by way of example: • the oxidation of water (H2O) into oxygen (O2), • the oxidation of chloride (Cl) into chlorine (Cl2), • the oxidation of hydroxide (OH-) into oxygen (O2), • the oxidation of a primary alcohol into an aldehyde, • the oxidation of a secondary alcohol into a ketone, • the carbonylation of an alcohol into dialkyloxalate, • the carbonylation of an amine into oxamide or oxamate • the dehydrogenation of ethane (C2H6) into ethylene, • the oxidation of ethanol to 2-chloroethanol.

[0381] According to a particular embodiment, the present invention relates to a use as defined above, in which the electrolysis reaction is a reaction of reduction of carbon dioxide to carbon monoxide.

[0382] The reduction of carbon dioxide to carbon monoxide is a cathodic reaction, taking place at the cathode. This reaction can in particular be carried out using a cathode comprising cobalt phthalocyanine as a catalyst or comprising silver nanoparticles.

[0383] According to a particular embodiment, the present invention relates to a use as defined above, in which said electrochemical reaction is the hydrolysis reaction of water forming oxygen and hydrogen

[0384] According to a particular embodiment, the invention relates to the use as defined above, in which at least two electrolysis cells of the invention as defined above are used in parallel or in series.

[0385] According to a particular embodiment, the invention relates to the use as defined above, in which at least two electrolysis cells of the invention as defined above are used in parallel.

[0386] The term “cells placed in parallel” means the paralleling in the supply circuits of the injection and supply channels distributing the electrolysis cells in parallel.

[0387] According to a particular embodiment, the invention relates to the use as defined above, in which at least two electrolysis cells of the invention as defined above are used in series.

[0388] The term "cells placed in series" means the placing in series in the feed circuits of the injection and supply channels distributing the electrolysis cells in series. A series arrangement of the feed flow circuits advantageously makes it possible to recover the product from the first cell (for example CO) to inject it as a reactant flow into the second cell where a carbonylation reaction would take place.

[0389] Advantageously, the paralleling of pairs of cells placed in series can also be implemented.

[0390] Another object of the present invention relates to an installation comprising at least two electrolysis cells of the invention as defined above, placed in parallel or in series.

[0391] According to a particular embodiment, the invention relates to an installation comprising at least two electrolysis cells of the invention as defined above, placed in parallel.

[0392] According to a particular embodiment, the invention relates to an installation comprising at least two electrolysis cells of the invention as defined above, placed in series.

[0393] According to a particular embodiment, the invention relates to an installation comprising a plurality of electrolysis cells of the invention as defined above, placed in parallel and in series.

[0394] Another subject of the present invention relates to an electrochemical method implemented in an electrolysis cell according to the invention to convey a reactant (R) in the form of bubbles or films selectively through one of the porous electrodes of said cell: • A preliminary step A of determination in said electrolysis cell according to the invention as defined above: • of the range of values ​​D1REG1 of the total volume flow rate of the electrolyte introduced into the injection channels (6,7) and of the range D2REG1 of values ​​of the total volume flow rate of the reagent introduced into said at least one supply channel (5) associated with D1REG1, defining a regime REGI in which the bubbles or films of reagent move towards the lower housing containing the cathode of said electrolysis cell and • of the range of values ​​D1REG2 of the total volume flow rate of the electrolyte introduced into the injection channels (6,7) and of the range D2REG2 of values ​​of the total volume flow rate of the reagent introduced into said at least one supply channel (5) associated with D2REG2, defining a regime REG2 in which the bubbles or films of reagent move towards the upper housing containing the anode of said electrolysis cell and • said step A being in particular determined by experimental means or by numerical simulation, • a step 1 of introducing two electrolyte flows (El, E2) at the same total volume flow rate Dl, via the injection channels (6, 7) into an electrolysis cell of the invention, the two flows (El, E2) being directed so as to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode, • a step 2 of supplying a reagent (R), gaseous or liquid, at a total volume flow rate D2, into said electrolysis cell via the at least one supply channel (5), injecting said reagent (R) in the form of bubbles and / or films via the orifice (51) in the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7), • a step 3 of conveying the bubbles or films of reagent

[0395] towards the electrode of the lower housing (4), via the distribution channels (8) of the lower electrode housing, by applying a volume flow rate D1 chosen from the range of values ​​D1REG1 and a volume flow rate D2 chosen from the range of values ​​D2REG1, corresponding to the REGI regime

[0396] or

[0397] towards the electrode of the upper housing (3), by the distribution channels (8) of the upper electrode housing, by applying a volume flow rate DI chosen from the range of values ​​D1REG2 and a volume flow rate D2 chosen from the range of values ​​D2REG2, corresponding to the REG2 regime, • a step 4 of applying a potential difference between the cathode and the anode,

[0398] causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or in the form of films, mixed with the electrolyte at one of the electrodes,

[0399] the products formed during the electrolyte, in particular in the form of gas bubbles, on the surface of the anode and the cathode being transported during the passage of the electrolyte flows passing respectively through the anode and the cathode and heading towards the outlet orifices (31, 41).

[0400] Depending on the total volume flow rate of the electrolyte and the total volume flow rate of the reactant introduced into the electrolysis cell according to the invention, two different flow regimes of the reactant in the form of bubbles or films have been identified.

[0401] By "REGI regime" is meant a regime defined by the total volume flow rate of the electrolyte flows and by the total volume flow rate of the reactant which are introduced into the electrolysis cell in which the bubbles and / or the reactant films, which are generated by the mixing of the electrolyte and reactant flows, move towards the lower housing containing the cathode of said electrolysis cell.

[0402] By "REG2 regime" is meant a regime defined by the total volume flow rate of the electrolyte flows and by the total volume flow rate of the reactant which are introduced into the electrolysis cell in which the bubbles and / or the reactant films, which are generated by the mixing of the electrolyte and reactant flows, move towards the upper housing containing the anode of said electrolysis cell.

[0403] The range of values ​​of the volume flow rates of the electrolyte allowing the inertial regime to be reached is called DI REGI.

[0404] The range of values ​​of the reagent volume flow rates which is associated with D1REG1 and which makes it possible to reach the REGI regime is named D2REG1.

[0405] The range of values ​​of the volume flow rates of the electrolyte allowing the REG2 regime to be reached is called D1REG2.

[0406] The range of values ​​of the reagent volume flow rates which is associated with D1REG2 and which makes it possible to reach the REG2 regime is called D2REG2.

[0407] These ranges of volume flow rate values ​​of the electrolyte and the reactant can be determined experimentally or by numerical simulation for each embodiment of the electrolysis cell according to the invention.

[0408] It is understood that the ranges of values ​​D1REG1, D1REG2, D1REG1 and D2REG2 are dependent on the dimensions of the embodiment of the cell according to the invention.

[0409] Thus once the volume flow rates corresponding to the REGI and REG2 regimes have been determined completed, preliminary step A is no longer necessary for the implementation of steps 1 to 4 of the method according to the invention

[0410] It is also understood that for a fixed value of DI to reach the REGI regime, it is possible to define the associated range of values ​​D2REG1, which is therefore a function of DI and which can also then be defined by the ratio DI: D2.

[0411] Another object of the present invention relates to a method of the invention as defined above comprising: • a step 1 of introducing two electrolyte flows (El, E2) at the same volume flow rate Dl, from 80 to 2400 mL / min via the injection channels (6, 7) into an electrolysis cell according to the invention, the two flows (El, E2) being directed so as to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode, • a step 2 of supplying a reagent (R), gaseous or liquid, at a total volume flow rate D2, into said electrolysis cell via the at least one supply channel (5), injecting said reagent (R) in the form of bubbles and / or films via the orifice (51) in the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7), • a step 3 of conveying the bubbles or films of reagent

[0412] towards the electrode of the lower housing (4), via the distribution channels (8) of the lower electrode housing, by applying a volume flow rate D1 chosen from the range of values ​​D1REG1 and a volume flow rate D2 chosen from the range of values ​​D2REG1, corresponding to the REGI regime

[0413] or

[0414] to the electrode of the upper housing (3), through the distribution channels (8) of the upper electrode housing, by applying a volume flow rate D1 chosen in the range of values ​​D1REG2 and a volume flow rate D2 chosen in the range of values ​​D2REG2, corresponding to the REG2 regime, • a step 4 of applying a potential difference between the cathode and the anode,

[0415] causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or in the form of films, mixed with the electrolyte at one of the electrodes,

[0416] the products formed during the electrolyte, in particular in the form of gas bubbles, on the surface of the anode and the cathode being transported during the passage of the electrolyte flows passing through the anode and the cathode respectively and heading towards the outlet ports (31,41).

[0417] Advantageously, step 3 conveys the reagent into the lower housing, the volume flow rate of DI is from 80 to 2400 mL / min and is chosen in the REGI and D2 range so that the DI:D2 ratio is from 2 to 80.

[0418] Advantageously, step 3 conveys the reagent into the upper housing, the volume flow rate of DI is from 80 to 2400 mL / min and is chosen in the range REG2 and D2 so that the ratio DI: D2 is from 9 to 40.

[0419] According to a particular embodiment, the present invention relates to a method as defined above, in which step 1 of introducing two electrolyte flows is carried out before step 2 of supplying the reagent.

[0420] According to this embodiment, the electrolysis cell is first balanced with the electrolyte flow before supplying the reactant from the supply channel (51, 52).

[0421] According to another particular embodiment, the present invention relates to a method as defined above, in which step 1 of introducing two electrolyte flows is carried out before step 2 of adding a material, and step 4 of applying a potential difference is carried out after step 2.

[0422] According to another particular embodiment, the present invention relates to a method as defined above, in which step 4 of applying a potential difference is carried out before steps 1 and / or 2 and / or 3.

[0423] According to another particular embodiment, the present invention relates to a method as defined above, in which the electrolyte is a solution of a salt in a solvent.

[0424] The salt consists of an anion, and a cation, in particular an anion chosen from hydroxide, carbonate, bicarbonate, chloride, perchlorate, tetrafluoroborate, hexafluorophosphate, sulfate and phosphate, and a cation chosen from sodium, potassium, NH4+, alkyl ammonium, lithium and cesium.

[0425] More particularly, the salt is chosen from sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), lithium bicarbonate, tetraethyl ammonium carbonate, and cesium carbonate.

[0426] The solvent is in particular water, methanol, ethanol, tetrahydrofuran, or supercritical CO2, preferably water.

[0427] The electrolyte is in particular a 0.5 M aqueous solution of potassium bicarbonate (KHCO3).

[0428] Advantageously, the electrolyte comprises an additive.

[0429] By way of non-limiting example, the additive is chosen to promote the formation and transport of bubbles or films of reagent such as a surfactant modifying the surface tension.

[0430] As a non-limiting example, the additive is chosen to promote the transfer of ions such as ionomers, for example Nafion™ at 7%.

[0431] According to a particular embodiment, the invention relates to the process as defined above, in which the reactant (R) is in the form of a gas.

[0432] Advantageously the size of the bubbles, defined by their average diameter, is in a range of values ​​from 0.1 to 1.0 mm.

[0433] The range “from 0.1 to 1.0 mm” includes the following ranges of values: from 0.1 to 0.2 mm; from 0.2 to 0.3 mm; from 0.3 to 0.4 mm; from 0.4 to 0.5 mm; from 0.5 to 0.6 mm; from 0.6 to 0.7 mm; from 0.7 to 0.8 mm; from 0.8 to 0.9 mm; from 0.9 to 1.0 mm;

[0434] According to a particular embodiment, the invention relates to the process as defined above, in which the reactant (R) is chosen from ethylene, carbon dioxide (CO2), carbon monoxide (CO), dioxygen (O2), hydrogen (H2), dinitrogen (N2) and the mixture of said gases with an inert gas, preferably said gas is CO2.

[0435] According to a particular embodiment, the invention relates to the method as defined above, in which the reactant (R) is a gas, in particular CO2, with a cell according to the invention as defined above comprising two supply channels (51, 52), said method comprising: a step 1 of introducing two electrolyte flows (E1, E2) at the same volume flow rate D1, greater than or equal to 150 mL / min, via the injection channels (6, 7) of said electrolysis cell,

[0436] the total volume flow rate of the electrolyte being greater than or equal to 300 mL / min, a step 2 of supplying a reagent (R) at a volume flow rate D2, via two supply channels (51, 52) of said electrolysis cell, a step 3 of conveying the reactive gas bubbles

[0437] to the electrode of the lower housing (4), through the distribution channels (8) of the lower electrode housing, by applying a ratio D1: D2 between the volume flow rate of the electrolyte and the volume flow rate of the reagent of 5 to 80, preferably 15, a step 4 of applying a potential difference between the cathode and the anode,

[0438] causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or films, mixed with the electrolyte at the electrode in the lower electrode housing of said electrolysis cell.

[0439] According to a particular embodiment, the invention relates to the method as defined above, in which the reactant (R) is a gas, in particular CO2, with a cell as defined above comprising two supply channels (51, 52), said method comprising: a step 1 of introducing two electrolyte flows (E1, E2) at the same volume flow rate D1, less than 120 mL / min, via the injection channels (6, 7) of said electrolysis cell,

[0440]

[0441]

[0442]

[0443]

[0444]

[0445]

[0446] the total volume flow rate of the electrolyte being less than 240 mL / min, • a step 2 of supplying a reagent (R) at a volume flow rate D2, via two supply channels (51, 52) of said electrolysis cell, • a step 3 of routing the reactive gas bubbles to the electrode of the upper housing (3), through the distribution channels (8) of the lower electrode housing, by applying a ratio DI: D2 between the volume flow rate of the electrolyte and the volume flow rate of the reagent of 9 to 40, preferably 20, • a step 4 of applying a potential difference between the cathode and the anode, causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or films mixed with the electrolyte to the electrode in the upper electrode housing of said electrolysis cell. According to a particular embodiment, the invention relates to the process as defined above for the preparation of CO by electrochemical reduction of CO2, in which: - the reagent (R) is the CO2 introduced at a total flow rate of 20 mL / min (i.e. 10 mL / min per channel) - the electrolyte is a 0.5 M aqueous solution of sodium bicarbonate (KHCO3) at a total flow rate of 300 mL / min (i.e. 150 mL / min per channel), - the porous anode is carbon paper, in particular Sigracet® 39BB carbon paper from SGL Carbon, - the porous cathode is a carbon paper comprising silver nanoparticles as a catalyst, in particular Sigracet® 36BB carbon paper from SGL Carbon, - the applied potential is in a range of 4.2 to 6V, in particular chosen from 4.2V, 4.8V or 6V. According to a particular embodiment, the invention relates to the method as defined above, in which the reactant (R) is CO2 in gaseous form, with an electrolysis cell according to the embodiment of [Fig.5] comprising two supply channels (51,52), said method comprising: • a step 1 of introducing two electrolyte flows (E1, E2) at the same volume flow rate D1, greater than or equal to 150 mL / min, via the injection channels (6, 7) of said electrolysis cell, the total volume flow rate of the electrolyte being greater than or equal to 300 mL / min, • a step 2 of supplying a reactant (R) at a volume flow rate D2, via two supply channels (51, 52) of said electrolysis cell, • a step 3 of routing the reactive gas bubbles to the electrode of the lower housing (4), through the distribution channels (8) of the lower electrode housing, by applying a ratio Dl: D2 between the volume flow of the electrolyte and the volume flow rate of the reagent greater than 5, in particular from 10.0 to 20.0, preferably 15, • a step 4 of applying a potential difference between the cathode and the anode,

[0447] causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or films mixed with the electrolyte to the electrode in the lower electrode housing of said electrolysis cell.

[0448] According to a particular embodiment, the invention relates to the method as defined above, in which the electrodes comprise carbon paper, preferably with a porosity of 55 to 80%.

[0449] By way of non-limiting example, the carbon paper is chosen from: - Sigracet® 36BB with 75% porosity - Sigracet® 39BB with 80% porosity - Freudenberg™ H23C2 with 56% porosity - Freudenberg™ H23C4 with 60% porosity - Freudenberg™ H23C6 with 60% porosity - Freudenberg™ H23C9 with 66% porosity - Freudenberg™ H23C10 with 56% porosity - CeTech W1S1011 with 55% porosity.

[0450] According to a particular embodiment, the invention relates to the method as defined above, in which the anode comprises or consists of a nickel foam or a platinum element, in particular a platinum plate.

[0451] According to a particular embodiment, the invention relates to the method as defined above, in which the cathode comprises a catalyst in the form of metal nanoparticles, preferably chosen from Ag, AgNi, AgCo, CoPc (cobalt phthalocyanine), Ni-SAC (Nickel Single Atom Catalyst).

[0452] According to a particular embodiment, the invention relates to the method as defined above, in which the anode comprises or consists of an iridium oxide IrO2.

[0453] The following examples and Figures illustrate the invention, without limiting its scope. The Figures

[0454] [Fig.l] represents the diagram of a sectional view along the transverse plane (T) comprising the Y and Z axes of an electrolysis cell according to the invention. The cell comprises a central cavity (2), an upper housing (3) accommodating a porous anode (A) and comprising an outlet orifice (31) for the flows (SIA, S2A) having passed through the anode, a lower housing (4) accommodating a porous cathode (C) and comprising an outlet orifice (41) for the flows (SIC, S2C) having passed through the cathode, two series of five distribution channels (81, 82, 83) per electrode. Indeed, each series of distribution channels (81, 82, 83) is linked respectively to an electrode housing (3, 4). Each series of channels comprises a central distribution channel (81) and 4 lateral distribution channels (82, 83) including 2 lateral channels on one side (82) and the other (83) of the central channel. Each distribution channel, like the channels (82, 83), extends through an opening (821, 831) of the central cavity (2) to an opening (822, 832) on the electrode (A, C) of the housing (3, 4) to which it is attached. The openings of the channels (821, 831, 822, 832) are configured by their size to allow the routing of reactant gas bubbles and / or reactant films.The lateral distribution channels are inclined so as to allow the delivery of reactant gas bubbles and / or reactant films following the direction of the electrolyte flows to the electrode housing to which they are attached; thus the lateral distribution channels attached to the inner housing receiving the cathode have an inclination of angle a which is directed downwards, from the opening (821, 831) to the opening (822, 832), the value of the slope being (- tan a); similarly the lateral distribution channels attached to the upper housing receiving the anode have an inclination of angle a but which is directed upwards, from the opening (821, 831) to the opening (822, 832), the value of the slope being (+tan a).The cell comprises two rectilinear injection channels (6, 7) of uniform height, intended for the injection of the two electrolyte flows (El, E2), said channels (6, 7) being connected respectively to the central cavity (2) by two orifices (61, 71) located opposite each other, allowing the implementation of the "split" phenomenon. From each injection channel (6, 7) extends perpendicularly a supply channel (51, 52) via an orifice (511, 521) allowing the introduction of the reagent (R) in the form of bubbles and / or films into the electrolyte flows (El, E2).

[0455] In operation of the cell of [Fig.l], in a regime of electrolyte (E1, E2) and gas (R) flow rates in which inertial effects are predominant, the electrolyte flows (E1, E2), passing through the orifices (511, 512) which are distributed by a flow of reactant gas immiscible with the electrolyte, convey bubbles and / or films towards the central cavity (2) via the inlet orifices (61, 71). These reactant bubbles and / or films are conveyed towards the cathode located in the lower housing via the distribution channels (81, 82, 83) attached to the lower housing, passing through the openings (811, 821, 831) of the central cavity towards the openings (812, 822, 832) distributing the cathode. The “split” phenomenon generated by the fact that the orifices (61,71) are located face to face allows the fluidic communication of the flow with the porous electrodes.The generated flows (SIA, S2A, SIC, S2C) exit the cell respectively through the orifices (3, 4) each passing through one of the two electrodes and allow the transport of the products formed to each electrode without mixing said products from the anode with those from the cathode.

[0456] In operation of the cell of [Fig.l], in an electrolyte flow rate regime (El, E2) and gas (R) in which the effects of gravity / flotation are predominant, the electrolyte flows (El, E2), passing through the orifices (511,512) which are distributed by a flow of reagent gas immiscible with the electrolyte, convey bubbles and / or films towards the central cavity (2) via the inlet orifices (61, 71). These reagent bubbles and / or films are conveyed towards the anode located in the upper housing via the distribution channels (81, 82, 83) attached to the upper housing, passing through the openings (811, 821, 831) of the central cavity towards the openings (812, 822, 832) distributing the anode. The “split” phenomenon generated by the fact that the orifices (61,71) are located face to face allows the fluidic communication of the flow with the porous electrodes.The generated flows (SIA, S2A, SIC, S2C) exit the cell respectively through the orifices (3, 4) each passing through one of the two electrodes and allow the transport of the products formed to each electrode without mixing said products from the anode with those from the cathode.

[0457] [Fig.2] represents the results by numerical simulation of the displacement of bubbles or gas films for two different volume flow rate ratios of gases in a cell as described in [Fig.l]; part a) represents the simulation for the displacement of bubbles, obtained with a total liquid volume flow rate of 250 mL / min, i.e. a volume flow rate for each injection channel of 125 mL / min and a total gas flow rate set at 1.5 mL / min, i.e. a flow rate for each supply channel of 0.75 mL / min; part 2b) represents the simulation obtained for the displacement of bubbles with a total liquid volume flow rate of 200 mL / min, i.e. a volume flow rate for each injection channel of 100 mL / min and a total gas flow rate set at 1.5 mL / min, i.e. a flow rate per supply channel of 0.75 mL / min;

[0458] part c) represents the simulation for the movement of bubbles in the absence of distribution channels, obtained with a total liquid volume flow rate of 250 mL / min, i.e. a volume flow rate for each injection channel of 125 mL / min and a total gas flow rate fixed at 1.5 mL / min, i.e. a flow rate for each supply channel of 0.75 mL / min,

[0459] part d) represents the simulation in the case of film displacement, obtained with a total liquid volume flow rate of 640 mL / min, i.e. a volume flow rate for each injection channel of 320 mL / min and a total gas flow rate fixed at 43 mL / min, i.e. a flow rate for each supply channel of 21.5 mL / min.

[0460] [Fig.3] represents the results by numerical simulation of the effect of the porosity of the electrodes; part 3a) represents the velocity contours within the cell, on the upper part of [Fig.3], the porous electrodes are present with a porosity of 74%, on the lower part of [Fig.3] there is no porous zone, which is equivalent to a porosity of 100%; part 3b) represents the contours of gas fractions within the cell, on the upper part, the porous electrodes are present with a porosity of 74%, on the lower part there is no porous zone.

[0461] [Fig.4] shows in part a) the schematic of a prototype 2D cell using computer-aided design (CAD) and in part b) a photo of the 2D cell in operation.

[0462] [Fig.5] represents the diagram of a sectional view along the transverse plane (T) comprising the Y and Z axes of a 3D pilot electrolysis cell according to an embodiment of the invention. The cell comprises a central cavity (2), an upper housing (3) accommodating a porous anode (A) and comprising an outlet orifice (31) for the flows (SIA, S2A) having passed through the anode, a lower housing (4) accommodating a porous cathode (C) and comprising an outlet orifice (41) for the flows (SIC, S2C) having passed through the cathode, two series of 5 identical distribution channels (84, 85, 86, 87, 88) whose axis is perpendicular to the surface of the electrodes. Each series of distribution channels (84, 85, 86, 87, 88) is respectively linked to an electrode housing (3, 4).Each distribution channel (84, 85, 86, 87, 88) extends through an opening (841, 851, 861, 871, 881) from the central cavity (2) to an opening (842, 852, 862, 872, 882) on the electrode (A, C) of the housing (3, 4) to which it is attached. The channel openings are configured by their size to allow the conveyance of gas bubbles and / or reagent films. The cell comprises two rectilinear injection channels (6, 7) of uniform height, intended for the injection of the two electrolyte flows (El, E2), said channels (6, 7) being connected respectively to the central cavity (2) by two orifices (61, 71) located opposite each other, allowing the implementation of the "split" phenomenon. From each injection channel (6, 7) extends perpendicularly a supply channel (51, 52) through an orifice (511, 521) allowing the reagent (R) to be introduced in the form of bubbles and / or films into the electrolyte flows (El, E2).

[0463] [Fig.6] shows an exploded view of the 11 plates numbered PI to PI 1, the assembly of which constitutes a 3D pilot cell according to [Fig.5]: - The PI plate is one of the two terminal or end plates, called "end plates". It can be made of PEEK material by machining. It includes a central opening to introduce a connector connected to the orifice (31) for collecting the outgoing anolyte fluids (SIA, S2A) and the convergent part towards the outlet orifice (31) of the anode housing. This convergent part is in the form of a pyramid with a square base. - The P2 plate is a plate whose function is to be a seal between the PI and P3 plates. It includes a square-shaped recess in the center that is part of the anode housing. It can be made of peroxide-treated EPDM and is obtained by laser cutting. The P3 plate is a plate whose function is to be a current collector for the anode. It includes a square-shaped recess in the center to accommodate the porous anode (A). It can be made of steel by machining or by water jet cutting. The P4 plate is a plate whose function is to be a seal between the P3 and P5 plates. It includes a square-shaped recess in the center forming part of the distribution channels (84, 85, 86, 87, 88) attached to the anode electrode housing. It is made of peroxide-treated EPDM and is obtained by laser cutting. The P5 plate is one of the two plates on which the fluid circuits are etched, including the injection channels (6, 7), the distribution channels (84, 85, 86, 87, 88), the central cavity (2). It is made of PTFE. The P6 plate is a square plate whose function is to be a seal between the P5 and P7 plates. It includes a square-shaped recess in the center forming part of the central cavity (2) and part of the injection channels and the electrolyte reservoirs (111, 112) and the electrolyte inlets (121, 122). It is smaller than the other plates to be able to be inserted between the P5 and P7 plates, allowing said P5 and P7 plates to also be partially joined together. It can be made of peroxide-treated EPDM and is obtained by laser cutting. Plate P7 is the other of the two plates on which the fluid circuits are etched, including the injection channels (6, 7), the supply channels (51, 52), the distribution channels (84, 85, 86, 87, 88), the central cavity (2), the electrolyte reservoirs (111, 112) and the electrolyte inlets (121, 122), the reagent reservoirs (131, 132), the reagent reservoir inlets (141, 142). It can be made of PTFE. The P8 plate is a plate whose function is to be a seal between the P7 and P9 plates. It includes a square-shaped recess in the center forming part of the distribution channels (84, 85, 86, 87, 88) attached to the cathode electrode housing. It can be made of peroxide-treated EPDM and is obtained by laser cutting. The P9 plate is a plate whose function is to be a current collector for the cathode. It includes a square-shaped recess in the center to accommodate the porous cathode (C). It can be made of titanium by machining or by water jet cutting. The P10 plate is a plate whose function is to be a seal between the P9 and PI 1 plates. It includes a square-shaped recess in the center forming part of the cathode electrode housing. It can be made of peroxide-treated EPDM and is obtained by laser cutting. - The Pli plate is the other of the terminal or end plates, called "end plates". It can be made of PEEK material by machining. It includes a central opening for introducing a connector connected to the orifice (31) for collecting the outgoing catholyte fluids (SIC, S2C) and the convergent part towards the outlet orifice (41) of the cathode housing. This convergent part is in the form of a pyramid with a square base. It also includes 4 openings, two openings for introducing two connectors bringing the electrolyte flows (El, E2) to the electrolyte inlets (121, 122) supplying the reservoirs (111, 112) and two openings for introducing two connectors bringing the gaseous reagent flows (R) to the reagent inlets (141, 142) supplying the reservoirs (131, 132).

[0464] The assembly of plates PI, P2 and P3 forms the upper anode housing (3).

[0465] The assembly of plates P4 and P5 forms the distribution channels (84, 85, 86, 87, 88) attached to the anode electrode housing.

[0466] The assembly of the plates P5, P6 and P7 forms the central cavity (2), the injection channels (6, 7), the supply channels (51, 52), the electrolyte reservoirs (111, 112).

[0467] The assembly of plates P7 and P8 forms the distribution channels (84, 85, 86, 87, 88) attached to the electrode housing of the cathode and the reagent reservoirs (131, 132).

[0468] The assembly of plates P9, P10 and PI 1 forms the lower cathode housing (4).

[0469] Plates P8, P9 and P10 include 4 openings corresponding to the openings allowing the connectors for the electrolyte and reagent flows to pass through.

[0470] The set of plates PI to PI 1 comprises 9 openings (15) at the periphery of the plates intended for the insertion of clamping means, such as a screw and a bolt. These openings (15) and the clamping means are non-limiting examples constituting means for assembling the plates to form the cell.

[0471] [Fig.7] represents a photo of the square plate P7, part 7a) is a view of the outer face exposed at P8, part 7b) a view of the inner face exposed at P6.

[0472] The outer face of P7 (part a) comprises:

[0473] - the five distribution channels (84, 85, 86, 87, 88) attached to the housing of the cathode electrode, the channels are in the form of a rectangular parallelepiped with an axis perpendicular to the plane of the plate. The openings of said channels are rectangular with a length Lo2 equal to the width Lal of the central cavity (2), they are aligned along the length Loi of the central cavity (2) in a regular manner, perpendicular to this length Loi. A thickness of Hs relative to the surface of the outer face, between the openings of the channels (84, 85, 86, 87, 88) is present to ensure the maintenance of the electrode and the height of the distribution channels,

[0474] - the two supply channels (51, 52) passing through said plate,

[0475] - two reagent reservoirs (131, 132) located symmetrically with respect to the center of the plate,

[0476] - two openings (121, 122) passing through the plate corresponding to the inlets of electrolyte to the electrolyte tanks,

[0477] - the 9 openings (15) for the assembly clamping means.

[0478] The inner face of P7 (part b) comprises:

[0479] - a part of the central cavity (2) in the form of a parallelepiped rectangle having a funnel shape on each of the two sides corresponding to the width of said rectangle, which converges towards the inlet orifice of the injection channels (61, 71)

[0480] - the five distribution channels (84, 85, 86, 87, 88) attached to the housing of the cathode electrode, the channels being in the form of a rectangular parallelepiped with the axis of the channel perpendicular to the plane of the plate. The openings of said channels are rectangular of length Lo2 which is equal to the width of the central cavity (2); they are aligned along the length Loi of the central cavity (2) in a regular manner, perpendicular to this length Loi,

[0481] - an imprint for the introduction of the P6 plate serving as a watertight seal,

[0482] - the two injection channels (6, 7) facing each other, extending respectively from orifices (61,71)

[0483] - two electrolyte reservoirs (111, 112) located symmetrically with respect to the center of the plate distributing the injection channels

[0484] - two openings (121, 122) passing through the plate corresponding to the inlets of electrolyte to the electrolyte tanks, and

[0485] - the 9 openings (15) for the assembly clamping means.

[0486] [Fig.8] represents a CAD diagram of the outer face of P7 facing the plate P8, described in [Fig.7].

[0487] [Fig.9] represents the assembly of plates P5 and P7 in section along plane (V); part a) is a view of the outer face of P7 facing P8; part b) is a perspective view; part c) is a cross-sectional view; part d) is a view of the outer face of P5 exposed to P4.

[0488] (P5) represents the plate P5, (P7) represents the plate P7, (2) represents the cavity central (2), (Lal) represents the width of the central cavity, (51) represents the supply channel passing through the plate P7, (84, 85) represent the distribution channels, (842, 852) represent the openings of the distribution channels in contact with the surface of the electrode, (Lo2) represents the length of the opening of the distribution channels, (121) represents the inlet of the electrolyte reservoir, (131) represents the reagent reservoir, (15) represents the openings passing through the means of tightening and assembly.

[0489] [Fig. 10] represents the assembly of plates P5 and P7 in section along plane (T); part a) is a view of the outer face of P7 facing P8; part b) is a perspective view; part c) is a cross-sectional view; part d) is a view of the outer face of P5 exposed to P4.

[0490] (P5) represents the plate P5, (P7) represents the plate P7, (2) represents the cavity central cavity, (Hc) represents the height of the central cavity, (51, 52) represent the two supply channels passing through the P7 plate, (6, 7) represent the injection channels, (61, 71) represents the inlet orifices of the injection channels in the central cavity, (84, 85, 86, 87, 88) represent the distribution channels, (Ws) represents the width of the distribution channels, (Hs) represents the height of the distribution channels, (122) represents the inlet of the electrolyte reservoir, (131) represents the reagent reservoir, (15) represents the openings passing through clamping and assembly means.

[0491] [Fig. 11] represents the assembly of plates P5 and P7 in section along a diagonal of the cell; part a) is a view of the outer face of P7 facing P8; part b) is a perspective view; part c) is a cross-sectional view; part d) is a view of the outer face of P5 exposed to P4.

[0492] (P5) represents the plate P5, (P7) represents the plate P7, (2) represents the cavity central, (51) represents a supply channel passing through the P7 plate, (84, 85, 86, 87, 88) represent the distribution channels, (841, 881) represent the openings of the distribution channels opening onto the central cavity, (842, 882) represent the openings of the distribution channels in contact with the surface of the electrode, (111) represents the electrolyte reservoir, (121, 122) represent the inlet of the electrolyte reservoirs, (131) represents the reagent reservoir, (15) represents the openings passing through clamping and assembly means.

[0493] [Fig. 12] shows the diagrams of the assembly of plates P6 and P7 from different views; part a) is a view of the inner face of P7 on which plate P6 is embedded and said view facing P5,

[0494] part b) represents the diagrams of the cell cut along the plane (V), respectively from top to bottom, of a view of the inner face of P7+P6 facing P5, of a perspective view, of a transverse view, and of a view of the outer face of P7 exposed to P8,

[0495] part c) represents the diagrams of the cell cut along the plane (T), respectively from left to right, of a view of the inner face of P7+P6 facing P5, of a perspective view, of a cross-sectional view, and of a view of the outer face of P7 exposed to P8,

[0496] part d) represents the diagrams of the cell in section along a diagonal of the cell, of a view of the inner face of P7+P6 facing P5, of a view in perspective, a cross-sectional view, and a view of the exterior face of P7 exposed to P8.

[0497] (P6) represents the plate P6 presented in hatched form, (P7) represents the plate P7, (511, 521) represent the orifice respectively of the supply channels opening towards the injection channels, (6, 7) represents the electrolyte injection channels, (61, 71) represent the inlet orifices towards the central cavity of the injection channels, (84, 85, 86, 87, 88) represent the distribution channels, (111, 112) represent the two electrolyte reservoirs, (121, 122) represent the inlet of the electrolyte reservoirs, (15) represents the openings passing through clamping and assembly means.

[0498] [Fig. 13] represents the different stages of the assembly of the PI to Pli plates of a 3D cell according to [Fig.6];

[0499] part a) is a photograph of the terminal plate Pli comprising the eight openings for the clamping means, the four openings for the introduction of the two electrolyte flows and the two reagent flows, an orifice in the center inscribed in an inverted pyramid with a square base forming the converging part of the cathode housing;

[0500] part b) is a photograph of the sealing plate P10 affixed to the plate PI 1, the plate P10 comprising a square recess in the center, the eight openings of the clamping means and the four openings for introducing the flows; the recess and the openings correspond to those of the plate PI 1;

[0501] part c) is a photograph of the titanium plate P9 comprising a square recess in the center, the eight openings of the clamping means, the four openings for introducing the fluxes, in correspondence with those of the plates PI 1 and P10, and a tab-shaped part intended for the current connectors for the application of an electric voltage,

[0502] part d) is a photograph of a square surface cathode, placed in the center of the recess of P9, the cathode is for example a gas diffusion electrode (GLD) comprising a porous carbon paper;

[0503] part e) is a photograph of the sealing plate P8 affixed to the plate P9, the plate P8 comprising a square recess in the center, the eight openings of the clamping means and the four openings of the incoming flows, which are in correspondence with those of the previous plates P10, P10 and P9;

[0504] part f) is a photograph of the plate P7 affixed to the plate P8 exposing its inner face comprising the imprint intended for the plate P6, an imprint of the central cavity, the openings of the distribution channels, the injection channels and the electrolyte reservoirs, the plate P7 comprising the eight openings of the clamping means and two openings of the incoming flows communicating with the electrolyte reservoirs which are in correspondence with those of the previous plates P10, P10 and P9, two of the flow openings relating to the flow of the reagent are closed by the plate P7;

[0505] part g) is a photograph of the plate P6 in its imprint on the plate P7, it comprises a recess in the shape of the central cavity comprising the injection channels and the electrolyte reservoirs;

[0506] part h) is a photograph of the plate P5 affixed to the plates P6 and P7 exposing its outer face comprising the five distribution channels attached to the anode housing and the openings of these distribution channels in contact with the surface of an anode, the plate P7 comprising the eight openings of the clamping means in correspondence with those of the preceding plates, the two flow openings relating to the electrolyte flows are closed by the plate P5;

[0507] part i) is a photograph of the sealing plate P4 affixed to the plate P5, the plate P8 comprising a square recess in the center, the eight openings of the clamping means corresponding to those of the previous plates;

[0508] part j) is a photograph of a square surface anode, placed in the center of the obviousness of P4, the porous anode is for example a gas diffusion electrode (GLD) comprising a porous carbon paper;

[0509] part k) is a photograph of the steel plate P3 comprising a square recess in the center, the eight openings of the clamping means, and a tab-shaped part intended for the current connectors,

[0510] part 1) is a photograph of the sealing plate P2 affixed to the plate P3, the plate P2 comprising a square recess in the center, the eight openings of the clamping means, the recess and the openings are in correspondence with those of the plate P3;

[0511] part m) is a photograph of the outer face of the terminal plate PI affixed to the plate P2, the plate PI comprising the eight openings for the clamping means, an orifice in the center on which is mounted a flow outlet connector.

[0512] [Fig. 14] represents photographs of the cell assembled according to [Fig. 13].

[0513] [Fig. 15] represents in part a) a photograph in operation of the cell according to [Fig. 6] without application of an electrical voltage allowing to visualize the gaseous path of the reactant R, namely the CO2, towards the catholyte formed by the outgoing flows (SIC, S2C) in the flow outlet connector; and in part b) a photograph in operation with an electrical voltage allowing the visualization of the formation of gas bubbles in the outlet connectors of the anolyte formed by the outgoing flows (SIA, S2A) and of the catholyte formed by the outgoing flows (SIC, S2C).

[0514] [Fig. 16] represents an embodiment of a P7 plate according to its inner face in which the injection channels are rectilinear from the electrolyte reservoir to the inlet orifice of the central cavity.

[0515] [Fig. 17] represents an embodiment of a P7 plate according to its inner face comprising roughness elements between the inlet orifices of the central cavity and the openings of the distribution channels.

[0516] Example 1: Numerical simulation: effect of the electrolyte / gas flow rate ratio

[0517] The numerical simulations were carried out on the cell configuration presented in [Fig.l], by OpenFoam (Open Field Operation and Manipulation), a software developed by the company OpenCFD Ltd.

[0518] The parameters entered for the cell are: - H height of the injection channels: 2mm - W the width of the supply channels of: 1mm - Hs the height of the intake channels of: 0.5mm - Ws the width of the intake channels of: 2mm - Electrode porosity: 70%

[0519] The parameters introduced concerning the flows are: - total flow rate of the liquid stream in the injection channels varying from: 200 to 300 mL / min. - total flow rate of the gas flow in the supply channels set at 1.5 mL / min

[0520] Note that in all the simulations, gravity was oriented from top to bottom, the objective then being to direct the gas bubbles towards the lower electrode in order to ensure that the separation takes place and is due to the cell and the conditions of use.

[0521] The results at a given instant of the simulation are presented in [Fig.2], which represents the contours of the gas fraction of the bubbles in the liquid inside the cell.

[0522] Part a) of [Fig.2] represents the simulation obtained with a total liquid volume flow rate of 250 mL / min, i.e. a volume flow rate for each injection channel of 125 mL / min and a total gas flow rate fixed at 1.5 mL / min, i.e. a flow rate for each supply channel of 0.75 mL / min.

[0523] Part b) of [Fig.2] represents the simulation obtained with a total liquid volume flow rate of 200 mL / min, i.e. a volume flow rate for each injection channel of 100 mL / min and a total gas flow rate fixed at 1.5 mL / min, i.e. a flow rate per supply channel of 0.75 mL / min.

[0524] Numerical simulations in the case of liquid-gas and the resulting analyses have shown that in addition to the laminar or turbulent aspect of the liquid flow, good operation of the cell is ensured by the fact that the liquid and gas flow rates are regulated so as to form bubbles and / or gas films whose diameter is less than the height of the liquid supply channel. This has made it possible to limit the ohmic resistance in the cell and to ensure that the reactants gaseous are well transported by the liquid phase without being penalized by the low solubility of certain reagents, such as carbon dioxide CO2.

[0525] For appropriate liquid flow rate / gas flow rate ratios, such as those in part a) of [Fig.2], it is possible to obtain a regime in which the inertial effects are predominant over the buoyancy / gravity effects. Indeed in [Fig.2] part a), we can very clearly see small bubbles moving towards the bottom of the cell, carried by the intake channels of the lower housing.

[0526] For lower liquid flow rate / gas flow rate ratios, the gas bubbles see their diameter increase which makes them more sensitive to gravity / flotation forces to the detriment of inertial effects (i.e. the gas bubbles being lighter than the liquid, they float and are carried towards the upper electrode).

[0527] Thus, depending on the liquid flow rate / gas flow rate ratio and the dimensions of the cell channels, in particular the intake channels, it is possible to suitably choose the regimes and to switch from one regime to another.

[0528] Furthermore, the simulations show that the sum of the heights H and Hs fixes the distance between the electrodes (value typically between 1 mm and 6 mm) while the ratio between H and W must be greater than 1 so as to ensure the correct ratio between the liquid and gas flow rates. Ws must be of the same order of magnitude as H so as not to limit the passage of bubbles and / or gas films towards the electrodes.

[0529] The angle of inclination of the distribution channels can be set between 14° and 90° depending on the manufacturing process chosen and the simulation results show good results with all the values ​​tested in this interval. On the other hand, below 14° of inclination, the separation of the products is not ensured and the manufacturing of the cell is extremely complex.

[0530] The role of the distribution channels is to modify the direction of the incident flow of the liquid / gas mixture, while accelerating it locally. Thus the inertial forces applied to the bubbles and / or gas films are greater and especially more significant than the gravity / flotation effects. In the absence of these channels, the results show that the gravity / flotation effects take over and the bubbles and / or films move mainly towards the upper electrode. This is illustrated in [Fig.2] part c) where the contours of the gas fraction in the cell are represented in the case where the distribution channels are present ([Fig.2] part a) and in the case where they are absent ([Fig.2] part c). In both cases, the total volume flow rates of liquid and gas are identical.

[0531] Example 2: Numerical simulation: effect of porosity

[0532] In [Fig.3] part a) the velocity contours within the cell are represented. In the upper figure the porous electrodes are present (porosity; i.e. ratio of the volume of the pores of the electrode to the total volume of the electrode; of the order of 75%), in the lower figure there is no porous area (i.e. the porosity is 100%).

[0533] In both cases, the total volume flow rates for the gas and liquid fractions are identical.

[0534] In [Fig.3] part b) are represented the contours of gas fractions within the cell. In the upper [Fig.3] part b), the porous electrodes are present (porosity; i.e. ratio of the volume of the pores of the electrode to the total volume of the electrode; of the order of 75%), in the lower [Fig.3] part b) there is no porous zone (i.e. the porosity is 100%).

[0535] In both cases, the total volume flow rates for the gas and liquid fractions are identical.

[0536] Simulation results indicate that porous electrodes contribute to cell operation.

[0537] Porosity induces a form of blocking which modifies the distribution of speeds and therefore the general topology of the flow as illustrated in [Fig.3] part a).

[0538] By limiting the speed, the porous electrodes make it possible to homogenize the speed distributions over the entire surface where without an electrode most of the energy is concentrated around the meeting point of the two liquid flows. This therefore makes it possible to limit the parasitic phenomena (vortices and recirculation zones) which prevent the transport of gas towards the lower zone of the cell (and at the same time promote mixing, see [Fig.3] part b) bottom where the agglomeration of gas bubbles is favored).

[0539] Example 3: Setting up the prototype - 2D cell - Validation of the concept

[0540] In order to confirm the results of the numerical simulations, a first experimental validation for the fluidic dimensioning of the cell was carried out using a first 2D cell prototype.

[0541] [Fig.4] part a) is a view of the CAD used, showing the footprint of the cell subject of the invention with the liquid supply channels (left and right, horizontal arrows) and the gas supply channels (left and right, vertical arrows). The cell outlets are represented by the black circles. For ease of prototyping, the distribution channels are inclined at 90°.

[0542] [Fig.4] part b) is a photo of the experiment in operation on which the contours of the gas zones are delimited by the dotted lines. The gas pockets from the gas supply channels enter the cell and are carried by the flow of liquid (colorless) then move towards the lower porous zone (the porous electrodes are the gray rectangles located on either side of the distribution channels, these are nickel foam) and exit through the corresponding outlet. At this stage, there is no trace of gas in the upper part of the cell, as desired and predicted by numerical simulations.

[0543] Example 4: Setting up the pilot cell

[0544] The next step consisted of the design and manufacture of a functional electrolyser.

[0545] [Fig.5] represents the diagram of a functional, designed and manufactured pilot electrolyser cell.

[0546] [Fig.6] details the different parts which constitute said electrolyser, obtained by the assembly of 11 plates, noted PI to PI 1: • The PI and PI 1 plates constitute the end plates and are made of PEEK. They group together the different connectors for bringing and collecting fluids, reagents and oxidation-reduction products. • Plates P3 and P9, intended to accommodate the porous anode and cathode respectively, include the current collectors that ensure electrical contact with the electrodes. Note that in the 3D pilot cell, the current collector dedicated to the cathode is made of titanium (which is chemically inert to CO2 and CO) while that dedicated to the anode is made of stainless steel. Depending on the desired reactions, other materials can be considered. • Plates P2, P4, P6, P8 and P10 are the joints between the different adjacent plates and are made of peroxide-treated EPDM. • The two plates P5 and P7 comprise the flow channeling circuit which constitutes the main part of the electrolyser as defined in figures 7 to 12; they are made of PTFE.

[0547] [Fig.7] shows photos of plate P7 showing the different elements present in the flow channel circuit.

[0548] Figures 8 to 12 represent the diagrams of the different sectional views along the planes (V) and (Ho) and along a diagonal of the cell for the assemblies of the plates P5 and P7 and the plates P7 and P6.

[0549] [Fig. 13] represents the different stages of assembly of the different elements of the pilot cell.

[0550] Example 5: Operation of the pilot cell for the formation of CO by reduction of CO2.

[0551] a) Validation of the routing of gas bubbles.

[0552] As predicted by numerical simulations, once the gas flow rate / electrolyte flow rate ratio is adjusted to reach the regime in which inertial effects are predominant and the porous electrodes are installed, the separation of the reactants takes place. In [Fig.15] part a), we can see a snapshot of an experiment without application of electrical voltage, so there is no reduction of CO2 to CO, this is only a first phase of validation of the fluid part of the concept.

[0553] The tube on the left is from the anode and contains mostly liquid (some bubbles are present and mainly due to surface tension issues).

[0554] The central tube on the right is connected to the cavity downstream of the cathode where the CO2 must go. We can clearly see large pockets of gas and bubbles which prove the correct functioning of the electrolyser from a strictly fluid point of view. For information, the liquid flow rate is set at 200mL / min and the gas flow rate was measured at 19mL / min.

[0555] b) Operation of the pilot cell

[0556] The next step was to test the electrochemistry; for this, a silver nanoparticle catalyst was deposited on the cathode (the anode remained blank) and a potential difference (total) of 4.2V was applied between the anode and the cathode. Analyses of the collected gases show the presence of CO, which indicates that at least part of the injected CO2 was indeed directed towards the cathode and underwent a reduction to CO. The results also show a production of O2 which is consistent with the expected oxidation at the anode.

[0557] In [Fig. 15] part b) we can see a snapshot of these tests. The tube on the left still corresponds to the anode outlet and the tube on the right opposite to the cathode. This time, in the presence of a potential difference we can observe a large pocket of gas on the left (O2) and bubbles of CO2 and CO on the right.

[0558] Example 6 - Electrochemistry Reaction Tests

[0559] The electrochemical cell according to figures 1 to 13, 15 and 16 is used in an electrochemical reaction. It is configured with:

[0560] - an anode comprising nanoparticles chosen from a nickel foam, a platinum plate or iridium oxide

[0561] - a cathode comprising nanoparticles chosen from Ag, AgNi, AgCo, CoPc and Ni-SAC

[0562] An aqueous electrolyte optionally comprising an additive chosen from a surfactant or ionomer (7% Nafion) is circulated in the cell using pumps through the central cavity at a flow rate of 80 to 2400 mL / min.

[0563] The supply channels supply the reactant (in particular gaseous CO2) to the cathode at a flow rate of 80 to 2400 mL / min.

[0564] A potential difference is applied between the cathode and the anode.

[0565] The products leaving the cell are collected.

Claims

Claims

1. Membrane-free electrolysis cell, comprising: • a solid body (1) and • two porous electrodes, an anode (A) and a cathode (C), • two injection channels (6, 7) of two electrolyte flows (El, E2), and • at least one supply channel (5, 51, 52) of at least one reagent (R), said solid body (1) comprising: • two electrode housings, upper (3) and lower (4), respectively comprising outlet orifices (31, 41), • a central cavity (2) located between said electrode housings, • a plurality of distribution channels (8, 81, 82, 83), each distribution channel connecting a part of the central cavity (2) by an opening (811, 821, 831) to a part of the surface of one of the electrode housings by an opening (812, 822, 832), the axis of each distribution channel being defined by the straight line segment connecting the center of the opening of the central cavity (811, 821, 831) with the center of the opening on the surface of the electrode (812, 822, 832), at least three distribution channels (8) being present for each electrode housing (3, 4), including a central distribution channel (81) and two lateral distribution channels (82, 83), in which: • said porous anode (A) and said porous cathode (C) are respectively contained in the upper (3) and lower (4) electrode housings, • the at least one supply channel (5) extends from one of the injection channels (6, 7) through an orifice (511, 521) of diameter W towards the outside of the cell, and is capable of being connected to a supply of reagent (R), • each injection channel (6, 7) extends from the central cavity (2) through an orifice (61, 71) of height H to the outside of the cell, and is capable of being connected to an electrolyte supply, • the central distribution channel (81) of a housing of an electrode is of height Hs, and its axis is perpendicular to the surface of said electrode and extends from the central cavity (2) through an opening (811) of width Wsc to an opening (812) of width Wsce on the surface of the electrode, • each lateral distribution channel (82, 83) of an electrode housing has a height Hs, extends from the central cavity through an opening (821, 831) of width Wsl to an opening (822, 832) of width Wsle on the surface of said electrode and its axis is perpendicular to said surface of the electrode or has an inclination of an angle a (9), angle between the axis of said distribution channel and its orthogonal projection on the surface of said electrode, said at least one supply channel (5) being capable of conducting said at least one reagent (R), gaseous or liquid, and of injecting said reagent (R) in the form of bubbles and / or films through the orifice (51) into the injection channel (6, 7) transporting the electrolyte, so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7), the two injection channels (6, 7) being capable of conducting the electrolyte from outside the cell towards the central cavity (2) and of introducing two flows of electrolyte through the respective orifices (61, 71) of the injection channels (6, 7), said two injection channels (6, 7) and said orifices (61, 71) being positioned so as to allow the two electrolyte flows (E1, E2) to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode, said two central distribution channels (81), respectively of the housings (3, 4) of the anode and of the cathode, being capable of passing the separate electrolyte flows (SIA, S2A, SIC, S2C) from the central cavity (2) to the outlet orifices (31, 41) of the housings (3, 4) by crossing respectively the anode (A) and the cathode (C), said lateral distribution channels (82, 83) being configured by their arrangement, their dimension and their orientation relative to the surface of the electrode, to conduct the bubbles and / or the films of the reagent (R) from the openings (821, 831) towards the openings (822, 832), and depending on the flow rate of the electrolyte flows and that of the reagent, to conduct the bubbles and / or the films of the reagent from the central cavity (2) selectively towards one of the housings (3, 4) containing respectively the anode (A) and the cathode (C).

2. Electrolysis cell according to claim 1, said electrolysis cell comprising two reagent supply channels (51, 52), respectively connected to the injection channels (6, 7).

3. Electrolysis cell according to one of claims 1 to 2, wherein each electrode housing (3,4) comprises n lateral distribution channels (82,83), n being an even number from 2 to 10, in particular n is equal to 4.

4. Electrolysis cell according to one of claims 1 to 3, wherein the width Wsl of the openings of the lateral distribution channels on the surface of the cavity (821, 831) is 1.0 mm to 20.0 mm, greater than the size of the bubbles and / or the thickness of the films comprising the reactant in order to allow the passage and conveyance of said bubbles or said reactant film and / or wherein the height Hs of the distribution channels (8, 81, 82, 83) is 0.5 to 5.0 mm and / or wherein the angle a is 14° to a value less than or equal to 90°, in particular the axis of the distribution channels (8, 81, 82, 83) are perpendicular to the surface of the electrodes and / or wherein the opening of the distribution channels (811, 821, 831) is in oval or circular shape or rectangular or square.

5. Electrolysis cell according to one of claims 1 to 4, in which the central cavity (2) of the solid body has a height Hc of 1.0 to 6.0 mm, and / or in which the central cavity (2) of the solid body is inscribed in a rectangular parallelepiped of width La and length Lo and height Hc, preferably the width La being 2.0 to 100.0 mm, the length Lo being 2.0 to 100.0 mm and represents the distance between the orifices (61, 71) of the two injection channels (6, 7).

6. Electrolysis cell according to one of claims 1 to 5, in which the electrode housings have a shape comprising a portion converging towards the outlet orifices (31, 41).

7. Electrolysis cell according to one of claims 1 to 6, wherein the height H of the injection channel (6,7) is 1.0 to 6.0 mm, preferably 2.0 mm and / or wherein the width W of the supply channel (5,51,52) is 0.5 to 2.5 mm, preferably 0.5 mm.

8. Electrolysis cell according to one of claims 1 to 7, wherein the ratio between the surface area of ​​the injection channel (6,7) and the surface area of ​​the orifice of the supply channel (51) is 4.0 to 15.0 or wherein the ratio between the height H of the injection channel (6,7) and the diameter W of the orifice of the supply channel (51) is 2.0 to 15.0, preferably 4.

0.

9. Electrolysis cell according to one of claims 1 to 8, in which the porous cathode and / or anode have a theoretical porosity Pt, defined as the ratio of the volume of the pores of the electrode to the total volume of the electrode, of less than 80%, in particular from 25 to 80%, in particular approximately 70%.

10. Electrolysis cell according to one of claims 1 to 9, in which the difference in porosity δ between the cathode and the anode is less than or equal to 5.0%, in particular said difference is 0.0 to 5.0%, preferably less than 1.0%, preferably the porosity of the cathode and the anode are identical.

11. Electrolysis cell according to one of claims 1 to 9, wherein the difference in porosity δ between the cathode and the anode is 5.0 to 20.0%, preferably 5.0 to 15.0%, more preferably 5.0 to 10.0%.

12. Electrolysis cell according to claim 1, comprising: • a solid body (1) and • two porous electrodes, an anode (A) and a cathode (C), • two injection channels (6, 7) for two electrolyte flows (E1, E2), and • two supply channels (51, 52) for at least one reactant (R), said solid body (1) comprising: • two electrode housings, upper (3) and lower (4), respectively comprising outlet orifices (31, 41), • a central cavity (2) located between said housings electrode and which fits into a rectangular parallelepiped of height Hc, length Loi and width Lal, with faces (a, b, c, d, e, f), faces (e) and (f) being the upper and lower faces of dimensions Loi and Lal, the faces (a) and (b) being parallel to each other and of dimensions Lal and Hc, the faces (c) and (d) being parallel to each other and of dimensions Loi and Hc, • a center of symmetry (I) through which passes a plane of symmetry (Ho) parallel to the faces (e, f), a plane of symmetry (V) parallel to the faces (a, b) and a plane of symmetry (T) parallel to the faces (c, d); • ten distribution channels including five distribution channels (84, 85, 86, 87, 88) per electrode housing, each distribution channel has the shape of a rectangular parallelepiped of height Hs, length Lo2 and width Ws, the length Lo2 being identical to the width Lal of the central cavity, each distribution channel connects a part of the central cavity (2) by an opening (841, 851, 861, 871, 881) of rectangular shape of length Lo2 and width Ws, to a part of the surface of one of the electrode housings by an opening (842, 852, 862, 872, 882) of the same shape and the same dimensions as said opening (841, 851, 861, 871, 881), so that the five distribution channels (84, 85, 86, 87, 88) per electrode housing are parallel along their length Lo2 and preferably spaced regularly along the length Loi of the cavity, • the orifices (61,71) of the injection channels (6,7) are positioned face to face respectively at the center of the faces (a) and (b) on the plane (T) • possibly means (10) for directing the electrolyte flows on the faces (a, b) in the form of a funnel extending from an orifice (61, 71) towards the faces (c) and (d) and po- located in front of the opening of a distribution channel, for a homogeneous distribution of the electrolyte flow between the faces (c) and (d), in which: • said porous anode (A) and said porous cathode (C) are respectively contained in the upper (3) and lower (4) electrode housings, • each injection channel (6, 7) is along the axis (Y) corresponding to the intersection of the planes (Ho) and (T) and connects the central cavity (2) by an orifice (61, 71) to an electrolyte reservoir (111, 112) supplied by an electrolyte inlet (121, 122), • each supply channel (51, 52) extends from an injection channel (6, 7) by an orifice (512, 521) of diameter W to a reservoir (131, 132) of reagent supplied by a reagent inlet (141,142), • the centers of the orifices (512, 521) of the supply channels (51, 52), the axes of the injection channels (6, 7) and the centers of the orifices (61,71) of the injection channels (6,7) are contained in the plane of symmetry (T).

13. Electrolysis cell according to one of claims 1 to 12, in which the solid body (1), the injection channels (6, 7), the supply channels (51, 52), the electrolyte reservoirs (111, 112) and the reagent reservoirs (131, 132) are included in the same solid matrix (M).

14. An electrolysis cell according to claim 13, wherein said solid matrix (M) comprises or consists of an assembly of successively stacked plates.

15. Electrolysis cell according to one of claims 13 to 14, wherein said solid matrix (M) comprises or consists of: - at least one central plate or a set of central plates, said set being in particular constituted by two central plates, - two current collector plates each comprising a central opening on which is mounted respectively porous anode and cathode electrodes - two end plates configured to enclose the plate assembly and respectively comprising the outlets (31, 41), - sealing plates located between two plates of said central plates, said current collector plates and said end plates, - clamping means (15), - two electrolyte flow inlets (121, 122), - two reagent flow inlets (141,142), in which said at least one central plate is configured to comprise: - the injection channels (6, 7) and the electrolyte reservoirs (111,112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83), or the central plates of said assembly are configured so as to comprise, by assembling said central plates of said assembly and sealing plates between said central plates of said assembly,: - the injection channels (6, 7) and the electrolyte reservoirs (111,112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83).

16. Electrolysis cell according to one of claims 13 to 15, in which said solid matrix (M) consists of an assembly of successively stacked plates, comprising 11 plates (PI, P2, P3, P4, P5, P6, P7, P8, P9, P10, Pli) including: - two central plates P5 and P7, - two current collector plates P3 and P9 each comprising a central opening on which the porous anode and cathode electrodes are mounted respectively - two end plates PI and PI 1 configured to enclose the plate assembly and respectively comprising the outlets (31, 41), - six sealing plates P2, P4, P6, P8 and P10 located between each of said plates (PI, P3, P5, P7, P9, Pli), P6 being located between P5 and P7, P4 and P8 being respectively adjacent to P5 and P7, P2 and P10 being located respectively between PI and P3 and between P9 and Pli, - clamping means (15), - two electrolyte flow inlets (121, 122) - two reagent flow inlets (141,142) in which the central plates P5 and P7 are configured so as to comprise, by assembling the plates P5, P6 and P7: - the injection channels (6, 7) and the electrolyte reservoirs (111, 112) - the supply channels (51, 52) and the reagent reservoirs (131, 132) - the central cavity (1) - distribution channels (81, 82, 83).

17. Electrochemical method implemented in an electrolysis cell according to one of claims 1 to 16, for conveying a reactant (R) in the form of bubbles or films selectively through one of the porous electrodes of said cell: • A preliminary step A of determination in said electrolysis cell according to the invention as defined above: • of the range of values ​​D1REG1 of the total volume flow rate of the electrolyte introduced into the injection channels (6,7) and of the range D2REG1 of values ​​of the total volume flow rate of the reagent introduced into said at least one supply channel (5) associated with D1REG1, defining a REGI regime in which the bubbles or films of reagent move towards the lower housing containing the cathode of said electrolysis cell and • of the range of values ​​D1REG2 of the total volume flow rate of the electrolyte introduced into the injection channels (6,7) and of the range D2REG2 of values ​​of the total volume flow rate of the reagent introduced into said at least one supply channel (5) associated with D2REG2, defining a regime REG2 in which the bubbles or films of reagent move towards the upper housing containing the anode of said electrolysis cell and • said step A being in particular determined by experimental means or by numerical simulation, a step 1 of introducing two electrolyte flows (El, E2) at the same total volume flow rate Dl, through the injection channels (6, 7) into an electrolysis cell of the invention, the two flows (El, E2) being directed so as to meet in the central cavity (2) and to cause a separation of each of the electrolyte flows, respectively into two parts, a first part of one of the flows (SIA) and a first part of the other flow (S2A) being conducted towards the anode, and a second part of one of the flows (SIC), and a second part of the other flow (S2C) being conducted towards the cathode, a step 2 of supplying a reactant (R), gaseous or liquid, at a total volume flow rate D2, into said electrolysis cell through the at least one supply channel (5), injecting said reactant (R) in the form of bubbles and / or films by the orifice (51) in the injection channel (6, 7) transporting the electrolyte,so as to obtain a mixture of bubbles and / or films of reagent with the electrolyte, at the orifice (61, 71) of the injection channel (6, 7), a step 3 of conveying the bubbles or films of reagent, to the electrode of the lower housing (4), through the distribution channels (8) of the lower electrode housing, by applying a volume flow rate D1 chosen from the range of values ​​D1REG1 and a volume flow rate D2 chosen from the range of values ​​D2REG1, corresponding to the REGI regime or towards the electrode of the upper housing (3), by the distribution channels (8) of the upper electrode housing, by applying a volume flow rate DI chosen from the range of values ​​D1REG2 and a volume flow rate D2 chosen from the range of values ​​D2REG2, corresponding to the REG2 regime, • a step 4 of applying a potential difference between the cathode and the anode, causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or in the form of films, mixed with the electrolyte at one of the electrodes, the products formed during the electrolyte, in particular in the form of gas bubbles, on the surface of the anode and the cathode being transported during the passage of the electrolyte flows crossing respectively the anode and the cathode and heading towards the outlet orifices (31, 41).

18. Method according to claim 17, comprising a step 1 of introducing two electrolyte flows (El, E2) at the same volume flow rate Dl, from 80 to 2400 mL / min via the injection channels (6, 7) into an electrolysis cell according to one of claims 1 to 15.

19. A method according to claim 17, wherein the reactant (R) is in the form of a gas, in particular wherein the reactant (R) is chosen from ethylene, carbon dioxide (CO2), carbon monoxide (CO), dioxygen (O2), hydrogen (H2), dinitrogen (N2) and the mixture of said gases with an inert gas, preferably said gas is CO2.

20. Method according to one of claims 17 to 18, in which the reactant (R) is a gas, in particular CO2, with a cell according to claim 12 comprising two supply channels (51, 52), said method comprising: • a step 1 of introducing two electrolyte flows (El, E2) at the same volume flow rate Dl, greater than or equal to 150 mL / min, via the injection channels (6, 7) of said electrolysis cell, the total volume flow rate of the electrolyte being greater than or equal to 300 mL / min, • a step 2 of supplying a reagent (R) at a volume flow rate D2, via two supply channels (51, 52) of said electrolysis cell, • a step 3 of conveying the reactive gas bubbles and / or the reagent films to the electrode of the lower housing (4), via the distribution channels (8) of the lower electrode housing, by applying a ratio DI: D2 between the volume flow rate of the electrolyte and the volume flow rate of the reagent of 5 to 80, preferably 15, • a step 4 of applying a potential difference between the cathode and the anode, causing an electrolysis reaction of the reagent (R) supplied in the form of bubbles and / or films, mixed with the electrolyte at the electrode in the lower electrode housing of said electrolysis cell.

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