DE102015015826A1 - Electrochemical module reactor - Google Patents

Abstract

The invention relates to a module reactor with an electrochemical cell, reactant feed and at least one heat exchanger. The invention is further directed to methods for performing an electrolysis or an electrosynthesis or for generating an electric current flow by means of a corresponding module reactor. The invention also relates to corresponding products produced by electrolysis or electrosynthesis.

Description

The invention relates to an electrochemical reactor, in particular an electrochemical module reactor for operation with at least two reactants. The reactor comprises at least one electrochemical cell, at least one reactant feed and at least one heat exchanger. The invention is further directed to methods which can be carried out by means of the module reactor and to products which can be produced therewith.

In generic module reactors, depending on the spatial distribution or configuration of the individual components of the reactor and depending on the course of the reaction, a problematic temperature distribution within the reactor may result. The temperature distribution can be so heterogeneous that individual areas of the reactor are driven in an optimal temperature range for each reaction, while other areas of the reactor have too low or too high temperatures for an optimal reaction sequence. As a result, the reactor efficiency is reduced and it can lead to further disadvantages such as damage to the reactor components and / or impairments of the reactants due to impermissible temperature values.

The object of the invention is therefore to provide a module reactor with an improved arrangement of the reactor components or to allow an improved arrangement of the heat exchanger or the corresponding lines of the heat exchanger, which can be acted upon by the temperature distribution within the reactor to make this optimal or even order advantageous to heat the reactor or the corresponding components quickly to operating temperature during the startup phase of the reactor. This provides a reactor with improved heat extraction, and it is possible to efficiently drain the increased waste heat output of an enhanced power density reactor from the reactor. By integrating a heat exchanger according to the invention and the other reactor components within a reactor module or the integration of said components within a common jacket, the overall system can furthermore be realized overall less complex and more compact than a single module.

The object underlying the invention is achieved by an electrochemical module reactor having the features of claim 1, with at least one hollow-body-shaped electrochemical cell, at least one reactant feed and at least one heat exchanger dissolved, wherein the electrochemical cell and the heat exchanger are at least partially disposed within a shell. Advantageous embodiments are the subject of the dependent claims.

Because according to the invention, the electrochemical cell, the Reaktantzuführung and / or the heat exchanger are not planar but for example, formed as a tubular fluid lines, a particularly space-saving and spatially close arrangement of the individual fluid lines within the shell is possible.

By a hollow-body-shaped electrochemical cell is meant here a cell which is not constructed in a planar manner but has an interior. The interior does not have to be limited on all sides. The interior may have one or more openings, it may be, for example, a tubular body.

If in the present description of a component is mentioned, then it is always meant that more than one corresponding component may be present or that at least one component must be present.

In a preferred embodiment, it is conceivable that the electrochemical cell and / or the reactant feed and / or the heat exchanger each comprise one or more fluid conduits or are formed as fluid conduits, and / or that the electrochemical cell comprises an electrolyte region, and / or that the reactant feed is at least partially disposed within the shell, and / or that the heat exchanger is designed as a heat exchanger with fluid circuit, in particular as a thermosiphon and / or as a heat pipe, and / or is designed as a thermocouple. The fluid lines can have any and not constant cross sections. In particularly preferred embodiments, the cross sections are circular. Equally, however, profiles with angular cross sections or with cross sections of any shape are conceivable. Due to complex cross-sectional geometries, it is conceivable, for example, to optimize the heat transfer with regard to the reaction and / or the durability of the membrane.

The electrolyte, which is encompassed by the electrolyte region, may be formed as a membrane, as doped ceramic and / or as immobilized acid. The reactant feed may be formed as a fluid conduit within the shell. However, it can also be provided that the Reaktantzuführung communicates via corresponding connections with the interior of the shell and in the interior itself no structures of Reaktantzuführung are provided. The heat exchanger may be formed, for example, as a tube bundle heat exchanger.

In a further preferred embodiment, it is conceivable that the fluid lines run parallel to one another and / or that the fluid lines of the electrochemical cell run at least partially within the fluid lines of the heat exchanger or vice versa. Due to the parallel arrangement of the fluid lines within the shell a particularly simple construction of the module reactor can be realized. If the jacket is designed as a cylindrical component, the fluid lines may extend, for example, parallel between the top surface and the bottom surface of the cylinder. Accordingly, in cuboidal or other embodiment of the shell, the fluid lines between opposite sides and in particular parallel to each other. If the fluid lines are designed with a simple, for example, circular, cross-section, they can thereby run parallel to each other. On the other hand, if the fluid lines or parts of the fluid lines are designed with complex cross-sections which have cavities, then other fluid lines can run within the cavities of the fluid lines formed in this way.

In a further preferred embodiment, it is conceivable that the fluid lines are at least partially formed as flow lines within an interior of the shell, wherein the flow lines each lead at one point into the interior of the shell and out at a different location from the interior of the shell. In the case of an essentially cylindrical jacket, the fluid lines can lead into the interior of the jacket, for example through a cover surface of the jacket, and out of its interior through a base surface of the jacket. This allows a particularly simple and particularly easy to manufacture geometry of the module reactor. The fluid lines can also be designed in Haarnadelbauweise.

In a further preferred embodiment, it is conceivable that the reactant feed comprises a porous passage region. The porous configuration of the passband allows an advantageously uniform flow through the passband. As a result, the reactant contained in the reactant feed or the reactant supplied by it is introduced particularly uniformly into the interior of the jacket. A correspondingly porous passband is also particularly easy to produce. If the reactant thus introduced then reacts within the interior of the jacket or in the region of the electrochemical cell with a further reactant, this can take place particularly uniformly, which is advantageous for the efficiency of the reaction.

In a further preferred embodiment, it is conceivable that the electrolyte region is provided in a central region of the electrochemical cell, and / or that the passage region is provided in a central region of the reactant feed. In this case, if the electrochemical cell and the reactant feed are designed as fluid lines or if they comprise fluid lines, then the middle area may mean an area located centrally in the axial direction of the fluid lines. If the fluid lines run straight through a cylindrically shaped jacket, then the electrolyte region and / or the passage region can be provided correspondingly in the axially middle region of the jacket. Due to the central arrangement of the corresponding areas, the greatest possible cooling of these areas can be effected, as a result of which reactions, which depend on cooling, can take place particularly efficiently. It is assumed that the greatest heat development occurs when the corresponding reaction takes place in the electrolyte region. If this area were not in the middle region of the jacket but in the region of, for example, its top surface or base surface, optimum cooling could not be ensured due to the heat exchange that is made difficult there. Similar arguments regarding heat transfer apply mutatis mutandis to heating the reactor during its heating phase.

In a further preferred exemplary embodiment, it is conceivable for the electrolyte region and / or the passage region to be provided on a jacket region of the fluid lines, or for the electrolyte region and / or the passage region to form a jacket region of the fluid lines, and / or for the electrolyte region to comprise an ion exchange Membrane comprises and / or that the passage region is permeable to reactant supplied by reactants. As a result, the jacket region of the fluid lines or a part thereof becomes a region through which a material throughput or transport between the insides of the fluid lines and their outer sides is made possible. The correspondingly shaped electrolyte region or passage region thus enables both mass transport through the respective region as well as in the axial direction of the corresponding fluid line. In this case, the electrolyte region or the passage region can not be planar but can be designed in accordance with the shape of the fluid line.

In a further preferred embodiment, it is conceivable that the electrochemical cell and the Reaktantzuführung separately supplied different reactants to the module reactor, and / or that the electrochemical cell, a reducing agent supply line of the module reactor and the Reaktantzuführung a Oxidant supply to the module reactor is or vice versa. The reaction of the reactants with one another can thus be carried out selectively in a specific region of the jacket or in specific regions of the electrochemical cell.

The reducing agent may be a fuel such as hydrogen or a hydrogen-containing compound or a mixture, and the oxidizing agent may be oxygen, oxygen or an oxygen-containing compound or a mixture. Thus, the module reactor can be used as a galvanic cell for voltage generation. Conversely, if an electrical voltage is applied to the electrochemical cell, the module reactor can be used by selecting appropriate reactants for electrolysis.

An embodiment of the module reactor with fuel supply and oxygen supply and with proton exchange membranes may relate to a PEM fuel cell. The hollow-body-shaped electrochemical cells of such a PEM fuel cell may have a membrane or an electrolyte, which is produced in a dip coating process in combination with a sol-gel process and consists of a polymer. In contrast to PEM fuel cells known solid oxide fuel cells (SOFC) operate at operating temperatures of about 800 ° C and at temperatures above 400 ° C. The presently usable proton exchange membranes operate at temperatures of less than 400 ° C, especially less than 300 ° C. In particularly preferred embodiments, the presently usable proton exchange membranes operate at temperatures of 120-250 ° C, and more preferably in the range of 120-160 ° C.

Conceivable, however, are embodiments in which the principle of the present module reactor is used to carry out other chemical reactions.

The invention is further directed to a method for carrying out an electrolysis or electrosynthesis or else for generating an electric current flow by means of an electrochemical module reactor according to any one of claims 1 to 8 and to an electrolysis product or Elektrosyntheseprodukt which by means of an electrochemical module reactor according to one of claims 1 to 8 is made.

Further details and advantages of the present invention will be explained with reference to the embodiments shown in the figures. Showing:

1 : Electrochemical module reactor in perspective sectional view;

2 : Electrochemical module reactor in sectional view with complex heat exchanger geometry;

3 : Construction of an electrochemical cell; and

4 FIG. 2: another embodiment of an electrochemical module reactor in a perspective sectional view. FIG.

1 shows a module electrochemical reactor 100 or reactor 100 with a plurality of electrochemical cells 1 , Reactant feeds 2 and a heat exchanger 3 , where the components 1 . 2 . 3 inside the coat 4 are arranged and parallel to the longitudinal axis of the cylindrical shell 4 are aligned. In this case, the electrochemical cells 1 one electrolyte area each 11 and the reactant feeds 2 one passband each 21 on. Through the electrolyte area 11 and the passband 21 can reactants in the interior 41 of the coat 4 or vice versa or from the interior 41 into the interior of the electrochemical cells 1 stream.

The electrochemical cells 1 , the reactant feeds 2 and the heat exchanger 3 are formed in the embodiment shown as pipes or fluid lines. The fluid lines run parallel to each other. It is also conceivable, however, an arrangement in which the fluid lines are arranged at an angle to each other. The fluid lines are formed in the embodiment shown as flow lines, which within the interior 41 of the coat 4 are arranged. The coat 4 itself may be formed substantially cylindrical or hollow cylindrical. 1 shows the perspective sectional view of a module reactor 100 with a correspondingly hollow cylindrical shell 4 , The fluid lines run substantially in the axial direction within the shell 4 between a deck area 42 and a floor space 43 of the coat 4 ,

In the reactant feeds 2 a porous area is shown, which is the pass band 21 can correspond. Is caused by the reactant feeds 2 For example, oxygen in the module reactor 100 initiated, it may pass through the porous region from the reactant feeds 2 and in the interior 41 of the coat 4 enter. The passband 21 However, it can also be designed as a nonporous region, in which, for example, corresponding passages instead of pores are provided for the substance transport. The oxygen or another reactant can be separated from the Reaktantzuführung 2 from substantially radially and axially outwardly toward the outer walls of the shell 4 stream. As 1 can be seen, the electrolyte areas 11 and the passbands 21 in middle areas of the electrochemical cells 1 or the reactant feeds 2 be provided. This allows them axially in a middle position of the shell 4 be arranged. They can be arranged so centrally that the top surface 42 and footprint 43 the cylinder of the mantle 4 the greatest possible distance exists. The electrolyte areas 11 and the passbands 11 can also be along the entire inside of the coat 4 lying length of the electrochemical cell 1 and reactant feed 2 or extend to parts of this length.

Further shows 1 that electrolyte area 11 and passband 21 on jacket areas of the fluid lines of the electrochemical cells 1 and the reactant feeds 2 are provided. The jacket regions of the fluid lines embodied in this way can thus both guide the reactants guided therein axially within the fluid lines and also allow them to escape from the fluid lines in the radial direction.

In one embodiment of the module reactor according to the invention 100 Both as a fuel cell and as an electrolysis or Elektrosynthesereaktor the electrochemical cells 1 and the reactant feeds 2 different reactants separated from each other in the module reactor 100 insert or from the module reactor 100 derived. The reactants in the case of the fuel cell may be, for example, a hydrogen-containing fuel and an oxygen-containing gas, or pure oxygen or hydrogen.

2 shows an embodiment of the module reactor 100 in which the heat exchanger 3 is not designed as a cylindrical tube or cylindrical fluid line, but has a complex geometry. Here, the heat exchanger 3 be shaped so that he has the electrochemical cells 1 and / or the reactant feeds 2 or at least partially or largely surrounds part of it. In the embodiment of 2 is the heat exchanger 3 constructed revolver drum-like and has corresponding distributed circumferentially arranged bushings 31 in which the electrochemical cells 1 be guided. The heat exchanger 3 can be rotationally symmetrical or have rotationally symmetric sections.

Through the space between the wall of the ducts 31 and within the implementation 31 extending reactant feeds 2 and / or the electrochemical cells 1 or the corresponding flow line of the electrochemical cells 1 extends, another reactant such as oxygen or oxygen-containing air may be passed. For the sake of clarity are not in all implementations 31 electrochemical cells 1 or reactant feeds 2 shown. The heat exchanger 3 may be in radially spaced sub-modules 32 . 33 be divided, which said distributed circumferentially arranged bushings 31 exhibit. The bushings 31 may be radially and circumferentially spaced apart electrochemical cells 1 and / or reactant feeds 2 be assigned or record this. The different submodules 32 . 33 may contain different heat transfer fluid streams. Thus, a cooling or heating power depending on the radial position of the electrochemical cells 1 be set. Radially further outward electrochemical cells 1 , which require, for example, an increased cooling capacity can be cooled, for example by means of increased heat transfer fluid rates. The subdivision of the heat exchanger 3 in submodules 32 . 33 can also be refined to that of a single electrochemical cell 1 or some electrochemical cells 1 one submodule each with its own heat exchanger fluid flow of the heat exchanger 3 or a submodule 32 . 33 of the heat exchanger 3 assigned. Inside the bushings 31 the submodules 32 . 33 can the electrochemical cells 1 be arranged as described. Through the space between the wall of the ducts 31 and within the implementation 31 extending electrochemical cells 1 can reactants in the axial and / or radial direction relative to the jacket 4 be guided.

3 shows the construction of an anode-supported electrochemical cell 1 which in the invention alternatively or in addition to a cathodic electrochemical cell 1 can be used. The electrochemical cell 1 is not planar but hollow cylindrical. Conceivable, however, are generally hollow body-shaped embodiments. It comprises radially inside a support electrode 12 and radially outside a sheath electrode 13 , Between carrier electrode 12 and sheath electrode 13 are from a membrane 14 separate catalyst layers of the anode 15 and the cathode 16 intended. Such a hollow cylindrical electrochemical cell 1 is suitable, together with heat exchanger 3 and reactant feeds 2 , which may also be configured hollow cylindrical, within the shell 4 a module reactor 100 to be arranged.

4 shows a further embodiment of an electrochemical module reactor 100 in a perspective sectional view with a plurality of electrochemical cells 1 and heat exchangers 3 , where the components 1 and 3 inside the coat 4 are arranged. The reactant feed 2 comprises in contrast to the embodiment of 1 none specifically within the coat 4 arranged fluid lines but it comprises passages, which is a feeding of the reactant or in the interior 41 of the coat 4 and removing excess reactants and / or reaction products from the interior 41 of the coat 4 enable.

The electrochemical cells 1 and the heat exchangers 3 are formed in the embodiment shown as pipes or fluid lines. The fluid lines run as in the example of 1 parallel to each other, but can also be arranged at an angle to each other instead. In contrast to the embodiment of 1 the reactant will not be within fluid lines in the interior 41 of the coat 4 guided, but over the cylinder surface of the jacket 1 in the interior 41 introduced. It is conceivable to introduce the reactants but also at any other point of the jacket 4 , Inside the coat 4 For example, the reactant (s) may react with others via the electrochemical cells 1 reacted reactants react. The heat exchanger 3 can be arranged so that they provide a heat transfer between the interior, which is as advantageous as possible for the corresponding reaction 41 of the coat 4 and allow an external heat sink and / or an external heat source.

The coat 4 itself may be formed substantially cylindrical or hollow cylindrical. 1 shows the perspective sectional view of a module reactor 100 with a correspondingly hollow cylindrical shell 4 , The fluid lines run substantially in the axial direction within the shell 4 between a deck area 42 and a floor space 43 of the coat 4 ,

Claims (10)

Electrochemical module reactor having at least one hollow-body-shaped electrochemical cell, at least one reactant feed and at least one heat exchanger, wherein the electrochemical cell and the heat exchanger are at least partially disposed within a shell. Electrochemical module reactor according to claim 1, characterized in that the electrochemical cell and / or the Reaktantzuführung and / or the heat exchanger each comprise one or more fluid conduits or are formed as fluid conduits, and / or that the electrochemical cell comprises an electrolyte region, and / or the Reaktantzuführung is at least partially disposed within the shell, and / or that the heat exchanger is designed as a heat exchanger with fluid circuit, in particular as a thermosiphon and / or as a heat pipe, and / or is designed as a thermocouple. Electrochemical module reactor according to claim 2, characterized in that the fluid lines run parallel to each other and / or that the fluid lines of the electrochemical cell run at least partially within the fluid lines of the heat exchanger or vice versa. Electrochemical module reactor according to claim 2 or 3, characterized in that the fluid conduits are at least partially formed as flow conduits within an interior of the shell, wherein the flow lines each lead at one point in the interior of the shell and lead out at a different location from the interior of the shell , Electrochemical module reactor according to one of the preceding claims, characterized in that the Reaktantzuführung comprises a porous passage region. Electrochemical module reactor according to at least one of claims 2 or 5, characterized in that the electrolyte region is provided in a central region of the electrochemical cell, and / or that the passage region is provided in a central region of the Reaktantzuführung. Electrochemical module reactor according to at least one of claims 2, 5 or 6, characterized in that the electrolyte region and / or the passage region are provided on a cladding region of the fluid conduits, or in that the electrolyte region and / or the passage region form a cladding region of the fluid conduits, and / or in that the electrolyte region comprises an ion-exchange membrane and / or that the passage region is permeable to reactant-fed reactants. Electrochemical module reactor according to one of the preceding claims, characterized in that the electrochemical cell and the Reaktantzuführung separately feed different reactants to the module reactor, and / or that the electrochemical cell is a reducing agent supply line of the module reactor and the Reaktantzuführung an oxidant supply line of the module reactor or vice versa. Process for carrying out an electrolysis or electrosynthesis or for producing a electrical current flow by means of an electrochemical module reactor according to one of claims 1 to 8. Electrolysis product or electrosynthesis product, which is produced by means of an electrochemical module reactor according to one of claims 1 to 8.

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