EP1815548A2

EP1815548A2 - Device for carrying out a chemical reaction

Info

Publication number: EP1815548A2
Application number: EP05821942A
Authority: EP
Inventors: Wolfram Kaiser; Conrad Pfender
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2004-11-18
Filing date: 2005-11-16
Publication date: 2007-08-08
Also published as: JP2008521184A; US20070287047A1; WO2006053727A9; CA2587241A1; WO2006053727A2; WO2006053727A3

Abstract

The invention relates to a device for carrying out a chemical reaction, particularly for producing electrical energy. The inventive device comprises at least one first flow channel for a first reaction medium, at least a second flow channel for a second reaction medium that is different from the first reaction medium, at least a third flow channel for a first temperature-adjusting medium and at least a fourth flow channel for a second temperature-adjusting medium that is different from the first temperature-adjusting medium.

Description

Device for carrying out a chemical reaction

The invention relates to a device for carrying out a chemical reaction with flow channels for tempering or reaction media. Furthermore, the invention relates to a disk package for forming such a device.

The conversion of chemical into electrical energy by means of such devices may represent an efficient and environmentally friendly method for recovering electric current from the operating media hydrogen and oxygen. In this case usually two spatially separated electrode reactions take place, in which electrons are released or bound. An example of two corresponding electrode reactions in a generic device are the following reactions:

H ₂ => 2 H ⁺ + 2 e ^" (anodic reaction)

2 H ⁺ + 2 e ^' + ^Λ AO ₂ => H ₂ O (cathodic reaction)

With another type, for example, the following reactions can be observed: H ₂ + O ^{2 '} => H ₂ O + 2 e ^" (Anodic Reaction I)

CO + O ^{2 '} => CO ₂ + 2 e ^" (Anodic Reaction II)

O ₂ + 4 e ^' => 2 O ^{2 "} (Cathodic Reaction)

Other generic devices have some other reactions. Common in each case is the transport of a species in an electrically non-neutral form by an electrolyte and the parallel transport of electrons through an outer conductor in order to return the species to an electrically neutral state after the transport process.

By electrically connecting the spatially separated reaction zones, part of the reaction enthalpy converted thereby can be obtained directly as an electric current. Usually, a plurality of reactors connected electrically in series are stacked on top of one another and a stack formed in this way is used as the current source. A single reaction unit consists of an electrolyte unit, such as membrane, which separates the reactants, in particular hydrogen and oxygen or hydrogen / carbon monoxide and oxygen, and has an ionic conductivity, in particular an H ⁺ proton conductivity or an O ^{2 "} - Conductivity, has, as well as from two occupied with catalyst E- electrodes, which are required inter alia for tapping the er¬ generated by the reaction unit electrical current.

The reactants, for example hydrogen and oxygen, and the reaction product water and optionally a medium which serves to dissipate excess heat of reaction flow through fluid channels, wherein the reactants do not necessarily have to be present in pure form. For example, the fluid on the cathode side may be air whose oxygen participates in the reaction. Especially when using a heat-dissipating medium is ensured by a thermal connection of je¬ respective fluid channels for a sufficient heat transfer between the respective fluids.

Reactants and reaction products are referred to in the context of the present invention as reaction media. A tempering medium is a medium which is suitable for adding or removing heat to a device or a reaction zone.

The waste heat produced in a generic device is usually removed via a cooling medium and a separate cooling circuit and has to be discharged against the environment. Since the temperature difference between the device and the environment is usually lower than in an internal combustion engine of comparable power, the cooling effort or the cooler size is often greater despite higher efficiency.

In principle, a distinction can be made between gas-cooled and liquid-cooled devices for carrying out a chemical reaction. In air-cooled devices, the heat balance is controlled by integrating suitable cooling channels into individual plates of a plate stack and flowing through these channels with an air flow, and the excess waste heat is removed with this air flow. Liquid-cooled devices, however, are traversed by a liquid cooling medium of mostly high heat capacity, which absorbs the waste heat produced during the chemical reaction and in an external, spatially separated from the device cooler, which in turn is mostly luftge¬ cooled, to the environment emits.

Due to the relatively low heat capacity of cooling air and the associated relatively large volume flows, the requirement for relatively large, straight air cooling channels results in the air-cooled arrangement. - A - in order to keep the pressure loss and thus the energy expenditure for the Kühlluft¬ stream within limits. Since the reaction media to be cooled are often also gaseous and have a specific heat capacity similar to the cooling air, air-cooled devices usually have a strong temperature gradient along the cooling air channel. In this case, in particular the region of the active reaction zone which is closest to the cooling air inlet is cooled particularly strongly, while hardly any heat transfer takes place in regions which are close to the cooling air outlet. It has been found that the resulting inhomogeneous temperature profile may adversely affect efficient operation of the device.

The liquid-cooled assembly may be problematic, especially when using polymer materials for the electrolyte membrane because of their susceptibility to contamination with metal ions. If, for example, a liquid-cooled device is to be operated in conjunction with a known aluminum heat exchanger, the use of a liquid cooling medium which can not transport metal ions, for example a heat transfer oil, or alternatively the use of an ion exchange cartridge for avoiding contamination of the polymer membranes Cleaning the liquid cooling medium neces sary. This results in disadvantages in the form of lower specific heat transfer performance (heat transfer oil) or in the form of additional system overhead (ion exchanger cartridge).

In order to produce the hydrogen-containing operating gas required in the device, in particular when producing gas on board motor vehicles, liquid fuels (for example gasoline, diesel, methanol, etc.) or gaseous fuels (for example natural gas) are used as the starting point. For the production of hydrogen-rich gas from these fuels, various methods are known which essentially one or the combination of several of the following chemical processes:

a) decomposition of the fuel, for example by so-called thermal cracking, into its starting materials, if appropriate via a catalyst. An example is the reaction of octane: C ₈ Hi ₈ - »8 C + 9 H ₂ .

b) Partial oxidation of the fuel over a catalyst with the addition of (air) oxygen in the stoichiometric or substoichiometric proportion. Examples are the reactions of octane: C ₈ Hi ₈ + 8 O ₂ → 8 CO ₂ +

9 H ₂ (stoichiometric) or C ₈ Hi ₈ + 4 O ₂ - »8 CO + 9 H ₂ (bottom stoichiometric).

c) steam reforming of the fuel over a catalyst with the addition of water. An example is the reaction of octane: C ₈ Hi ₈ + 16 H ₂ O →

8 CO ₂ + 25 H ₂ .

d) Autothermal reforming of the fuel by combining partial oxidation and steam reforming to the effect that the energy balance of the overall reaction is just compensated by combining the endothermic steam reforming and the exothermic partial oxidation.

In general, such a process takes place in a so-called reformer, whereby in practice no full conversion is achieved and a more or less high proportion of carbon monoxide remains in the gas produced. Subsequently, by using so-called shift stages using the

Water gas shift reaction (CO + H ₂ O → CO ₂ + H ₂ ) additional hydrogen at the expense of CO concentration can be obtained using a suitable catalyst. For further purification of the gas of CO, selective oxidation can be carried out over a catalyst suitable for this purpose. In this case, the remaining carbon monoxide is oxidized by the addition of (air) oxygen to carbon dioxide: 2 CO + O ₂ → CO ₂ .

For further purification of the gas from sulfur or sulfur compounds, a passive adsorption (for example on zeolites) or a catalytic transformation of the sulfur compounds present in the fuel or reformate to a suitable catalyst or adsorbent can be carried out. The desulfurization is fundamentally possible before reforming (on the liquid or vaporized fuel) or after the reforming (on the reformate). In the latter case, the sulfur compounds remaining in the format are reacted with hydrogen, for example by means of the process of HDS (hydrodesulfurization); The resulting H2S is then adsorbed on a suitable material (for example Cu-Zn pellets) and thus removed from the fuel gas.

Usually, many or all of these processes take place in devices designed specifically for this purpose. A schematic overview of the architecture of a fuel cell system is given in FIG. 8.

It is an object of the invention to provide an apparatus for carrying out a chemical reaction which has a high efficiency with relatively little effort.

This object is achieved by a device for carrying out a chemical reaction, which in each case has at least one, preferably a plurality of first flow channels for a first reaction medium, second flow channels for a second reaction medium, third flow channels for a first Tes tempering and fourth flow channels for a second Tempe¬ riermedium has.

Thus, according to the invention, at least four media can be conducted separately from one another. The reaction media serve to supply a chemical reaction zone with the media required for the chemical reaction, for example hydrogen and atmospheric oxygen, or a removal of one or more reaction products. With the aid of the first temperature-reducing medium, the waste heat produced in the device can be discharged directly to the environment, for example, or the required heat can be supplied directly to the device, in particular by means of a fluid delivery device, such as a pump, a blower or the like same. For this purpose, preferably ambient air is used as the first tempering medium, which is passed through the device in a suitably large amount. The second temperature control medium, for example cooling water, flows in a preferably closed circuit, preferably by means of a suitable fluid conveying device.

Under certain circumstances, a lesser structural complexity can be achieved with the device according to the invention if additional components such as temperature control tubes, pumps or heat exchangers are dispensable, since the device itself acts as a heat exchanger. In particular, by providing flow channels for different tempering media, a more homogeneous temperature distribution and, if appropriate, a more even temperature release or addition, and thus possibly an increased efficiency of the device is made possible. The use of two tempering media has an advantageous effect, which differs from one another in their heat capacity and / or their state of aggregation and / or when the flow channels for the tempering media have different shapes and / or cross-sectional areas. According to a preferred embodiment, the device according to the invention has a preferably diffusion-permeable membrane between a first and a second flow channel, so that the reaction media are separated from one another, wherein the chemical reaction is via, for example, ionic diffusion of one or more reactants through the membrane is made possible through.

According to an alternative embodiment, the flow channels for the reaction media communicate with one another so that the reactants come into direct contact with one another and can possibly intermingle with one another. As a result, the chemical reaction may be accelerated, so that the efficiency of the device increases.

The device according to the invention preferably has a fifth flow channel for a third temperature control medium, which differs from the first and the second temperature control medium. As a result, a loading of the device with three different tempering media of different function is made possible. For example, a tempering medium can be used for heat removal, heat supply, evaporation and / or catalytically assisted conversion of the temperature-control medium itself.

According to a preferred embodiment, at least one flow channel for a reaction medium communicates with a flow channel for a temperature control medium. As a result, the relevant flow channel for the temperature control medium can be used as a feed channel for fresh and possibly pretreated reaction medium.

According to an advantageous embodiment, a third or fourth flow channel has a catalyst and is particularly preferably catalytically coated. The first or second temperature control medium then absorbs heat by means of an endothermic reaction or gives off heat by an exothermic reaction so that, on the one hand, the heat removal and supply is assisted and, on the other hand, the device optionally has a further function, namely the performance of the catalyzed reaction , in particular a reforming, fulfilled.

Preferably, the catalyst is arranged on a surface which is thermally decoupled from other flow channels. Thus, the catalyzed reaction can also take place at a different temperature level than that of the other flow channels. The catalyst is particularly preferably arranged on a disk element that is thermally decoupled from the other flow channels. The thermal decoupling is effected in particular by projections on the channel wall and / or the disk element, in which case a heat flow from the channel wall to the disk element or vice versa is inhibited by only a punctiform and / or linear contact.

Additionally or alternatively, the respective channel wall and / or the disc element thermally decoupled from the respective channel wall has a thermal insulator formed in particular as a surface coating. Under certain circumstances, thermal isolation may also be advantageous in the case of flow channels without a catalyst.

According to a preferred embodiment, the disc element thermally decoupled from the respective channel wall comprises a honeycomb body, especially a catalytically coated honeycomb, in particular a honeycomb ceramic, which is particularly suitable with regard to thermal decoupling due to its starting material and either with or without the use of a punk - Can be used on a real plant. According to a further preferred embodiment, the disc element thermally decoupled from the respective channel wall comprises an extensive metal mesh or an expanded metal felt, which in a particularly preferred embodiment is electrically conductively connected to one or two channel walls of the flow field, for example by soldering.

According to a preferred embodiment, at least one third and / or fourth flow channel communicates with a first and / or second flow channel. As a result, at least one reaction medium also serves as a temperature medium, namely before or after the chemical reaction. This is for example a preheating of a reactant, optionally with recovery of reaction heat. Particularly preferably, the third or fourth flow channel is provided with a catalyst for this, so that at least one reactant can be produced in the device according to the invention with relatively little energy expenditure.

Further advantageous embodiments of the invention will become apparent from the claims and from exemplary embodiments, with reference to which the Er¬ invention is explained in more detail below with reference to the drawings. Show it:

1 shows a disk package for forming a Vorrich¬ device according to the invention in exploded view,

2 shows an apparatus for carrying out a chemical reaction in exploded view,

3 shows a temperature distribution over devices for carrying out a chemical reaction,

4 shows a device for carrying out a chemical reaction, 5 a disk package with two pairs of disks,

6 is a fragmentary cross section of three panes,

7 is a partial cross-sectional view of three panes,

8 is a diagram of a fuel cell system,

9 shows a cross section of a disk package,

10 is a cross section of a disk package,

Fig. 11 is a cross section of a disk package and

Fig. 12 a disc package.

The exemplary embodiment according to FIG. 1 comprises a plurality of disks (1, 2, 5, 6), of which two each form a pair (1, 2) or (5, 6). The disk pairs are advantageously designed as communicating half shells according to DE 102 24 397 A1. Between two of such pairs (1, 2) (5, 6), a third flow channel is arranged, with a turbulence insert formed as an air cooling flow field (3, 4), which can be supplied with cooling air as the first tempering medium, for example, by a blower (not shown) , A disk package is thus represented from the joined parts 1 to 6, which are connected to one another in a fluid-tight manner, for example by welding, soldering or mechanical Um¬ forms.

In a particularly preferred embodiment, the components 1, 2, 5 and 6 are made of stainless steel and welded or soldered together.

The Kühlflowfield (3,4), which also consist of a single component can, for example, made of aluminum and mechanically placed after the joining process of the components 1, 2, 5, 6. The disk package formed from all components then has flow channels that are independent of one another, for example for cooling air, cooling fluid, anode supply gas and cathode supply gas.

Fig. 2 also shows an exploded view of an arrangement of several disk packages (7) as a disk stack to form a device for carrying out a chemical reaction. The disk packages (7) are stacked alternately with membranes (8) which are provided with electrodes on both sides.

The disk packs joined in this illustration have an encircling seal (9), which has interruptions (10) for a flow through the first cooling medium cooling air to form inlet and / or outlet openings. The first temperature control medium is thus distributed outside of the disk elements onto the third flow channels formed by intermediate spaces between two disk elements or collected therefrom. For this purpose, a distributor and a collecting channel (not shown), which communicate with the third flow channels, laterally adjoin the disk stack. In addition, it is possible with the aid of suitable deflection channels to provide a serpentine flow through the third flow channels, wherein each of the two or more serpentine sections may in turn comprise a plurality of parallel flow channels, in particular from different interpane spaces. The reaction media and the second temperature control medium are discharged via distribution and collecting channels within the stack of disks, for which purpose the individual disks have, for example, rectangular openings. 3 shows the qualitative profile of the temperature T of a reaction medium along the length I of a cooling air channel of a known (11) and a device (12) according to the invention for carrying out a chemical reaction. It can be clearly seen that a more homogeneous temperature distribution along the cooling air channels can be achieved by means of an additional liquid cooling circuit. By arranging fourth flow channels for a liquid cooling medium in each case between the flow channels for the reaction media and the cooling air, the temperature profile along the cooling air channels is made particularly uniform.

In a further particularly preferred embodiment, a device according to the invention with internal (steam) reforming is used. This happens because, instead of cooling air, one of the reactants flows through the third flow channels and then through the first or second flow channels in that the first or second flow channels communicate with the third flow channels, for example via a connecting line or within the disk stack ,

In a more specific embodiment, an area for the evaporation of the liquid fuel is generated, which is functionally upstream of the actual reforming area, but does not have a catalytic coating to achieve evaporation without a chemical reforming reaction. In this application, the segments (3, 4) or a corresponding component are at least partially provided with a catalytic coating. In the event that evaporation of liquid fuel components is provided, no catalytic coating is applied in the evaporation zone, which begins at the reformate entry zone and has a suitable expansion along a channel. The proportion of electrically unusable waste heat of the chemically released energy results from the ratio of the difference between re¬ benibler heat of reaction [1, 48V] and the electrical cell voltage in each operating point to the reversible heat of reaction. If the reforming process is carried out in such a way that the amount of heat required for the evaporation and / or reforming corresponds to the waste heat, such a system can even be operated autothermally and completely without an external cooler.

In a particularly preferred embodiment, the cooling medium used for setting an isothermal state is a fuel-water mixture which is warmed up in the area of the cooling flow field between the plates (1-2) or (5-6) and in the following in the area of the reforming ungsflow- fields (parts 3-4) is steam reformed.

In a further preferred embodiment, the fuel-water mixture is conducted under pressure so that it is in liquid form in the region of the cooling flow field and depressurises before it enters the reforming flow field, so that a sudden evaporation occurs here as a preparation for the reforming reaction.

In a further preferred embodiment, the operating point or the waste heat of the stack is adjusted so that the process of heating the fuel-water mixture in connection with the steam reforming is energetically covered at least partially by the waste heat produced during the chemical reaction. so that an autothermal Be¬ drive is promoted. In principle, this arrangement is suitable for any endothermic or slightly exothermic reaction combination.

As part of a catalytically cooled device with internal reforming (for example, methanol reforming), the reforming by Under certain circumstances, the quasi-isothermal temperature distribution according to the invention in the entire catalytic coated region may be more efficient.

FIG. 4 shows a fuel cell system cluster 13 with bipolar plates 15, which is constructed, for example, according to FIG. 2. Third flow channels 14 in ei¬ ner cooling zone 23 serve a flow with cooling air. By using a particularly closed liquid cooling circuit by means of fourth flow channels which are not visible externally, the cooling effect of the cooling air can be transferred to adjacent bipolar plates, so that not every third flow channel has to be used for the cooling function. The third flow channels thus released to some extent can be used for various other tasks in the fuel cell system.

In an evaporation zone 16, water or a water-fuel mixture 18 is evaporated in third channels 17, so that it may be possible to dispense with an evaporator as a precursor for the reformer as an independent component.

A partial oxidation, an autothermal reforming or a steam reforming takes place in a reforming zone 19, the third flow channels 20 there optionally having a suitable catalytic coating of the channel walls with a catalyst suitable for the respective task. Under certain circumstances can thus be dispensed with a reformer as an independent component.

In a low temperature shift zone 21 third flow channels 22 are provided for a water gas shift reaction, which is optionally supported by means of a catalyst. Under certain circumstances can therefore be dispensed with an NT shift reactor as an independent component. The third flow channels of the different zones are connected to one another via suitable connection channels, not shown in more detail, so that the respective fluid, as indicated by the arrows 24, 25, passes from one zone into the next zone. In a similar manner, the prepared anode gas is fed to an anode gas distribution channel 27, as indicated by the arrows 26. In parallel, cathode gas 28 is supplied to a cathode gas distribution channel 29.

According to embodiments not shown, third flow channels for selective oxidation or an anode exhaust gas combustion are used in certain zones. The previously provided, separate components can then be eliminated in principle.

According to a further embodiment, by supplying third flow channels with reaction air for an ATR ("autothermal reforming") reformer, the required air is preheated, so that the ATR reaction may run more uniformly and a corresponding preheating step is omitted as an independent component.

According to a further embodiment, the cathodic gas is preheated by pressurizing third flow channels with reaction air for the cathode-side fuel cell process so that negative temperature effects (such as electrolyte aging, condensation, etc.) occurring at the cathode gas inlet of the fuel cell stack are reduced or prevented.

According to a further embodiment, integration of a suitable transformation catalyst (active desulfurization) or a suitable adsorbent (passive desulfurization) into the third flow channel, for example by coating the walls and / or by filling chemically active bulk material, such as Pellets, tablets etc., and securing against discharge from the flow channel region, for example by means of grids at both ends of the flow channels, makes it possible to remove the used fuel. In principle, this desulfurization can be carried out on the liquid or vaporous fuel before reforming or can also be carried out on the reformate after the reforming. As a result of the lowering of the sulfur content in the reformate achieved in this way, the deactivation of catalytically active components (eg shift stages) is reduced or avoided in the following and the service life and efficiency of the fuel cell system are increased.

In a particularly preferred embodiment, the bulk material is exchanged for unused goods after reaching a defined minimum activity threshold. To simplify this exchange, the bulk material in the form of a suitably shaped replacement cartridge can be inserted into the four-flow bipolar plate and optionally simply replaced.

A prerequisite for most of the above-mentioned objects is a relatively high temperature level, which is conveniently achieved by operating the fuel cell cluster in conjunction with membrane electrode assemblies using high temperature polymer electrolyte membranes and utilizing the appropriate rated operating temperatures (100 ° C). .200 ⁰ C) can be provided.

Here, a distinction must be made between processes which take place at cell temperature (for example evaporation, low-temperature (NT) shift reaction, cooling) and processes which, although capable of starting at cell temperature, are usually adiabatic in nature and at higher temperatures take place as cell temperature (for example, autothermal reforming, partial oxidation, low-temperature shift reaction, selective oxidation, anode exhaust gas combustion). In order to be able to drain processes of the latter type, for example, in a high-temperature polymer-electrolyte-membrane fuel cell system cluster, the formation of different temperature levels within the fuel cell system cluster is to be enabled. For this purpose, the catalyst suitable for the respective reaction is preferably arranged on a surface which is thermally decoupled from other flow channels.

According to FIGS. 5 and 6, a catalyst is arranged on a disk element 31 thermally decoupled from the other flow channels. The thermal decoupling is accomplished in particular by projections 32 on the channel wall of the third flow channel 33 by a heat flow is inhibited by the disc member 31 to the channel wall in that the disc member 31, the channel wall only selectively, namely at the tips of the projections, in particular is verlö¬ tet with the channel wall. By using the disk element 31, adiabatic reactions are decoupled from the wall temperature of the multi-function flow field, so that reactions with a higher temperature can take place here.

Alternatively or, as shown in FIG. 7, in addition to a single point contact and depending on the desired temperature, the reaction is by using thermal barrier coatings 34 on the channel walls of the first, second, third and / or fourth flow channels of the cell temperature ¬ door shieldable. Suitable for this purpose are ceramic thermal barrier coatings, such as aluminum oxide (Al ₂ O ₃ ), aluminum-titanium oxide (Al ₂ O ₃ ZTiO ₂ ), Zirkonkorung (Al ₂ O ₃ / ZrO ₂ ), mullite (Al ₂ O ₃ / SiO ₂ ), spinels (Al ₂ O ₃ MgO), zirconium oxide (Mg-ZrO ₂ ), zirconium silicate (ZrSiO ₄ ), etc.

In an embodiment, not shown, of a fuel cell system cluster, the fourth flow channels for the liquid coolant are replaced by a structure analogous to the design of a heat pipe. As a result, it is possible to dispense with the use of a pump for circulating the liquid cooling medium, as a result of which, if appropriate, a further space gain and, under certain circumstances, an improvement in the degree of system efficiency can be achieved.

Under certain circumstances, the invention makes it possible to provide a simplified system with which the multiplicity of components required in the prior art can be dispensed with and, if appropriate, a cost and / or installation space reduction is possible. In an advantageous embodiment, the device according to the invention summarizes all the essential components from FIG. 8 in a single assembly - a fuel cell system cluster. As a result, the space requirement of the fuel cell system is reduced and possibly achieved a cost reductions ucation. In other embodiments, only partial adoption of system functions in the fuel cell system cluster is realized, with further, functionally independent components remaining in the system.

FIG. 9 shows a cross-section of a disk pack arranged between an upper membrane electrode assembly (MEA) 41 and a lower MEA 42. First flow channels 43 serve to pressurize the upper MEA 41 with a cathode gas, while second flow channels 44 serve to apply an anode gas to the lower MEA 42. Third flow channels 45 serve to guide a first tempering medium, for example coolant or cooling air. The first flow channels 43 communicate via openings 46 in an adjacent disk with fourth flow channels, whereby a Kathodenengaszudosierung along the first flow channels is possible.

10 shows a cross section of a further disk package, which is arranged between an upper membrane electrode unit (MEA) 51 and a lower MEA 52. First flow channels 53 serve to the upper MEA 51 with a cathode gas, while second flow channels 54 serve to apply an anode gas to the lower MEA 52. Third flow channels 55 serve to guide a first tempering medium, for example cooling air. The first flow channels 53 communicate via aligned apertures 56 of two adjacent disks with the third flow channels 55, whereby a cathode gas metering, in particular with air or oxygen along the first flow channels, becomes possible. Fourth flow channels serve to guide a second tempering medium, for example liquid coolant.

In a particularly preferred embodiment, some or all of the third flow channels are connected on one side to a cathode gas source, such as a compressor, and sealed on the other side.

FIG. 11 shows a cross section of a disk pack disposed between a top membrane electrode assembly (MEA) 61 and a bottom MEA 62. First flow channels 63 serve to load the upper MEA 61 with a cathode gas, while second flow channels 64 serve to apply an anode gas to the lower MEA 62. Third flow channels 65 serve to guide a first tempering medium, for example coolant or cooling air. The first flow channels 63 communicate via apertures 66 in an adjacent disk with fourth flow channels 67, whereby a Kathodengaszudosierung spielsweise with reaction air along the first flow channels is possible. Fifth flow channels 68 serve to guide a third temperature medium, for example a liquid coolant or cooling air. The third flow channels 65 and / or the fifth flow channels 68 are in this embodiment also for the evaporation, implementation and The like of the first or third tempering used ver¬.

FIG. 12 shows a disk package with first flow channels 73 and second flow channels 74. Third flow channels 75 serve to guide a first temperature control medium, for example coolant or cooling air, while fourth flow channels 77, 78 serve to guide a second temperature medium. The third flow channels are subdivided into a plurality of subchannels by a plurality of disk elements 79 mounted in parallel, which are contoured in a particularly preferred embodiment, for example in the form of a corrugated fin. As a result, the surface of the third flow channels 75, which may be thermally decoupled from the first, second and / or fourth flow channels, is enlarged, for example, for a particularly catalytic reaction.

Claims

Patent claims

1. Apparatus for carrying out a chemical reaction, in particular for generating electrical energy, with at least one first flow channel for a first reaction medium, at least one second flow channel for a second reaction medium different from the first reaction medium, at least one third flow channel for a first tempering medium and at least one fourth flow channel for a second tempering medium which differs from the first temperature medium.

2. Apparatus according to claim 1, characterized by a plurality of first, second, third and / or fourth flow channels.

3. Device according to one of the preceding claims, gekenn¬ characterized by a fifth flow channel for a different from the first and the second temperature control third

Tempering.

4. Device according to one of the preceding claims, wherein at least one first and / or second flow channel with at least one third and / or fourth flow channel communicating ver¬ is connected, in particular via one or more openings in a partition wall between the first or second flow channel and the third or fourth flow channel.

5. Device according to one of the preceding claims, wherein the second temperature control medium differs in its heat capacity or its state of aggregation from the first temperature control medium.

6. Device according to one of the preceding claims, wherein the fourth flow channel differs in its shape or cross-sectional area from the third flow channel.

7. Device according to one of the preceding claims, wherein the first temperature control medium is gaseous and in particular comprises air or consists thereof.

8. Device according to one of the preceding claims, wherein the second temperature control medium is liquid and in particular water auf¬ has or consists thereof.

9. Device according to one of the preceding claims, wherein the first and / or the second reaction medium is gaseous and in particular hydrogen, oxygen or air or be¬ stands thereof.

10. Device according to one of the preceding claims, wherein at least a third and / or fourth flow channel a catalyst for a chemical reaction of the first or second

Tempering medium has.

11. Device according to one of the preceding claims, wherein the catalyst as a bulk material, in particular powder, granules, tablets, pellets or the like, is formed or is ent in a bulk material ent hold.

12. Device according to one of the preceding claims, wherein the catalyst is held in a particular replaceable cartridge, which is preferably designed as a cage for a bulk material.

13. Device according to one of the preceding claims, wherein the catalyst is arranged on a surface which is thermally decoupled from other flow channels.

14. Device according to one of the preceding claims, wherein the catalyst is arranged on one of other flow channels thermally ent¬ coupled disk element.

15. Device according to one of the preceding claims, wherein the respective channel wall and / or the thermally decoupled from other flow channels disc element has projections, wherein the channel wall and the thermisch decoupled from other flow channels disc element touch in particular only on the jumps.

16. Device according to one of the preceding claims, wherein the respective channel wall and / or the thermally decoupled from the respective channel wall disc element has a particular designed as O- berflächenbeschichtung thermal insulator.

17. Device according to one of the preceding claims, wherein the thermally decoupled disc element comprises a particular catalytically coated honeycomb body.

18. Device according to one of the preceding claims, wherein the thermally decoupled disc element consists partially or entirely of ei¬ NEM ceramic material.

19. Device according to one of the preceding claims, wherein the thermally decoupled disc element comprises a fiber material, in particular a knitted or felt.

20. Device according to one of the preceding claims, wherein the thermally decoupled disc element partially or wholly of ei¬ NEM metal and in particular with at least one Kanal¬ wall is electrically connected.

21. Device according to one of the preceding claims, wherein at least a third and / or fourth flow channel communicates with a first and / or second flow channel.

22. Device according to one of the preceding claims, gekenn¬ characterized by at least one first, second, third and / or vier¬ th distribution and / or collection channel for distribution or collection of the respective medium on or from the first, second, third or fourth flow channels.

23. Device according to one of the preceding claims, wherein the device comprises disc elements, wherein at least a first, second, third and / or fourth flow channel is formed by a Zwi¬ space between two adjacent disc elements.

24. Device according to one of the preceding claims, wherein two adjacent disc elements are formed as in particular zuwei¬ send to half shells.

25. Device according to one of the preceding claims, wherein at least a first, second, third and / or fourth flow channel is formed as an impression in a disc element.

26. Device according to one of the preceding claims, wherein at least a first, second, third and / or fourth flow channel is formed serpentine.

27. Device according to one of the preceding claims, wherein the disc elements have openings for the formation of the distribution and / or collecting channels.

28. Device according to one of the preceding claims, wherein at least one distribution and / or collection channel outside the disc is arranged and communicates with the gap between two disc elements.

29. Device according to one of the preceding claims, wherein the first and the second flow channel communicate with each other.

30. Device according to one of the preceding claims, wherein the first and the second flow channel are separated by at least one insbeson dere diffusion-permeable membrane.

31. Device according to one of the preceding claims, wherein disc elements made of metal or an alloy.

32. Device according to one of the preceding claims, wherein at least one first, second, third and / or fourth flow channel has at least one surface enlargement element.

33. Device according to one of the preceding claims, wherein at least one surface enlarging element is formed by a turbulence insert or by a wall embossing and / or embossing.

34. Device according to one of the preceding claims, wherein two adjacent disc elements are circumferentially sealingly connected to each other, in particular by welding, soldering and / or me¬ chanic forming.

35. Device according to one of the preceding claims, wherein a first, second, third and / or fourth flow channel is part of a closed circuit.

36. Device according to one of the preceding claims, wherein a first, second, third and / or fourth flow channel is part of a circuit with a fluid conveying device.

37. Device according to one of the preceding claims, wherein between a first and / or second flow channel and a third flow channel, a fourth flow channel is arranged.

38. Device according to one of the preceding claims, wherein at least one disc element has at least one recess, in particular an impression for forming a first, second, third and / or fourth flow channel.

39. Device according to one of the preceding claims, wherein the disc elements stacked on each other to form a stack of discs.

40. Device according to one of the preceding claims, wherein in each case some, in particular four disc elements stacked to a Schei¬ benpaket stacked, and that the disc packets are stacked alternately with membranes and / or electrolyte units to form a disc stack.

41. Disc package, in particular for forming a device according to ei¬ nem of the preceding claims, with at least two Scheiben¬ pairs, wherein a gap between the pairs of discs zu¬ least forms a third flow channel, and wherein each pair of two Schei¬ pair has discs whose space forms a fourth flow channel.