Plasma electrode assembly and plasma analysis device

Abstract

The invention relates to a plasma electrode assembly which comprises a cylindrical hollow outer electrode, an annular starting electrode which is electrically insulated and spaced from the outer electrode, and an inner electrode which is arranged in spaced relation within the outer electrode and the starting electrode, and the starting electrode (100) can be connected to a high-voltage source.

Description

[0001] Plasma electrode assembly and plasma lysis device

[0002] The invention relates to a plasma electrode arrangement and a plasma lysis device with such a plasma electrode arrangement.

[0003] It is known to separate hydrocarbons, such as methane, natural gas, biogas, or heavy oil, into carbon and hydrogen using the Kvaerner process in a plasma torch at approximately 1600 °C. Furthermore, the plasma gasification of solid or liquid organic starting materials is also known in principle. Kvaerner uses a hollow inner electrode arranged within an outer electrode to generate the plasma, as shown, for example, in WO 93 / 20152.

[0004] This is where the invention comes in, which aims to improve such a plasma electrode arrangement.

[0005] According to a first aspect, the invention relates to a plasma electrode assembly comprising a cylindrical hollow outer electrode, an annular ignition electrode arranged electrically insulated from and spaced from the outer electrode, and an inner electrode arranged spaced from the outer electrode and the ignition electrode, wherein the ignition electrode is connectable to a high-voltage source. The invention includes the finding that the use of a separate ignition electrode allows the distance between the inner and outer electrodes to be increased, thus enabling a higher performance of a plasma lysis device equipped with the plasma electrode assembly. Furthermore, the invention is based on the finding that the use of an ignition electrode also allows the use of different plasma gases.

[0006] With the help of an applied high voltage, an arc is built up between the ignition electrode and the inner electrode during ignition, which extends into a plasma space between the inner and outer electrodes and initiates the formation of a plasma between the inner and outer electrodes.

[0007] With the plasma electrode arrangement according to the invention, larger electrode systems can therefore be used stably for the dissociation of hydrocarbon-containing starting materials into molecular hydrogen and carbon at lower costs.

[0008] The inner electrode forms a counter electrode to the outer electrode and the ignition electrode.

[0009] Advantageous embodiments of the plasma electrode assembly according to the invention are described below. The additional features of the exemplary embodiments can be combined with one another to form further embodiments, unless they are expressly described as alternatives to one another in the description.

[0010] Nitrogen and / or hydrogen are preferred as plasma gases. Other gases such as ammonia, noble gases, or gas mixtures are also possible.

[0011] In one embodiment of the plasma electrode assembly, the ignition electrode is flattened on a side facing the outer electrode. This design promotes the extension and movement of the arc into a plasma gap between the inner and outer electrodes.

[0012] Preferably, the thickness of the ignition electrode decreases from a side facing away from the outer electrode to a side facing the outer electrode. This design also promotes the extension of the arc into a plasma gap between the inner and outer electrodes. The ignition electrode is preferably formed essentially as a hollow truncated cone. This allows both the decreasing thickness of the ignition electrode to be ensured in a geometry that is easy to manufacture and the accommodation of the inner electrode in the cavity of the ignition electrode.

[0013] In one embodiment, the ignition electrode has a mounting area with which it is mechanically connected to the outer electrode via insulating spacers. This enables simple assembly of the plasma electrode assembly, with the insulating spacers ensuring both insulation and maintaining a distance between the ignition and outer electrodes.

[0014] Preferably, an ignition gap between the ignition electrode and the inner electrode has a width in the range of 4 to 20 mm.

[0015] The plasma gap between the outer and inner electrodes is preferably more than 20 mm wide. Such a large gap allows for a higher voltage while maintaining the plasma, thus resulting in a higher yield.

[0016] Preferably, the outer electrode and / or the ignition electrode and / or the inner electrode comprise or consist of graphite. Graphite is particularly well-suited as an electrode material because it exhibits good conductivity and is easily moldable. Furthermore, the use of graphite electrodes in the processes described here prevents contamination of the resulting carbon, even when the electrodes wear out.

[0017] In a further embodiment, the plasma electrode arrangement further comprises a gas guiding device arranged on a side of the ignition electrode facing away from the outer electrode and at a distance therefrom, wherein the gas guiding device comprises channels and / or grooves for guiding gas and the channels and / or grooves are arranged in particular concentrically. A flow of the incoming plasma gas directed with the aid of the gas guiding device in addition to the annular ignition electrode promotes an extension of the ignition arc into a plasma space between the inner and outer electrodes and offers support in the formation of the plasma in the form of an arc or a torch. The gas guiding device preferably comprises at least one gas guiding ring with channels and / or grooves, which is arranged in a housing, preferably a ceramic tube.

[0018] The inner electrode is preferably hollow. This allows both plasma gas and, in certain applications, a starting material gas to be processed to be fed through the inner electrode.

[0019] The plasma electrode assembly preferably comprises an electrode changing system comprising a plurality of internal electrodes in a drum assembly of a turret system. The electrode changing system is configured to lower precisely one internal electrode into an interior space of the external electrode and, after a predetermined time or in response to a control signal, to raise the lowered internal electrode, rotate the drum by at least one position, and lower another internal electrode into the interior space. With the aid of such an electrode changing system, the internal electrodes, which regularly wear out during the process, can be easily replaced. Such an electrode changing system can also be used in plasma electrode assemblies without an ignition electrode.

[0020] It is further preferred that the plasma electrode arrangement comprises a bayonet connection for connection to a bayonet socket in an opening of a reaction chamber, wherein the outer electrode and ignition electrode are mechanically connected to the bayonet connection.

[0021] According to a second aspect, the invention relates to a plasma lysis device for splitting a starting material into at least one product gas and at least one by-product, comprising a plasma electrode arrangement according to the first aspect of the invention, at least partially arranged in a reaction chamber, at least one starting material supply in the reaction chamber, and a direct current source connected to the outer electrode. A plasma lysis device can also be referred to as an electrolysis or plasma electrolysis device.

[0022] The starting material can be gaseous, solid, or liquid. It can also be a mixture of different starting materials. The starting material preferably comprises at least one hydrocarbon and is preferably split into at least molecular hydrogen and solid carbon. The solid or liquid starting material can also contain oxygen compounds, which then also promote the formation of carbon monoxide or carbon dioxide, if desired.

[0023] The starting material can contain methane, for example. For example, the starting material can contain over 75% methane, preferably over 90% methane, for example between 90% and 99% methane. The methane is split into hydrogen and elemental carbon in the plasma; in particular, the chemical reaction n CH4 -> n C(s) + 2n H2 takes place, where n C(s) can contain various solid carbon structures, e.g., one or more carbon structures Ck with k less than or equal to n. Carbon structures can be, for example, elemental carbon particles, carbon nanotubes, fullerenes, carbon nanocones, or other carbon structures. The elemental carbon particles can, for example, have a size between 50 μm and 180 μm. Carbon layers can also form. This enables the efficient production of molecular hydrogen and elemental carbon from methane.

[0024] Other examples of hydrocarbon-containing feedstocks are naptha, flare gas, landfill gas and pure hydrocarbons such as pure propane.

[0025] The starting material can be natural gas, for example. Natural gas may, for example, contain the following substances: between 30% and 99% methane, e.g. between 75% and 99% methane, in particular between 90% and 99% methane, between 0% and 15% ethane, e.g. between 1% and 15% ethane, in particular between 1% and 3% ethane, between 0% and 10% propane, e.g. between 1% and 10% propane, in particular between 0.3% and 0.5% propane, between 0% and 1% butane, in particular between 0.1% and 0.2% butane, between 0% and 1% ethene, between 0% and 1% pentanes, in particular between 0.01% and 0.03% pentanes, between 0% and 1% hexane, in particular between 0.001% and 0.02% hexane, between 0% and 35% hydrogen sulphide, between 0% and 70% nitrogen, e.g. between 0% and 15% nitrogen, in particular between 0.5% and 1% nitrogen, between 0% and 10% carbon dioxide, in particular between 0.1% and 0.3% carbon dioxide.

[0026] Natural gas may also contain traces of oxygen, e.g., between 0.001% and 0.01% oxygen. Natural gas may also contain noble gases such as helium, argon, neon, krypton, or xenon, for example, in quantities between 0% and 15%.

[0027] Another preferred feedstock is biogas. This can be used, in particular, to produce syngas. For example, with a biogas composition of 50% CH4 and 50% CO2, a feed of 1:14 H2 and CO can be produced.

[0028] Other suitable solid or liquid starting materials include waste, from which hydrogen and usable by-products can be obtained cost-effectively, and in addition the burden of waste to be landfilled can be significantly reduced or even eliminated entirely. In particular, sewage sludge, biomass such as food scraps, manure, household waste, pharmaceutical waste, car tires, plastic waste, packaging waste, industrial waste, ASR (combustible, shredded waste from the automotive industry ASR consists of the following material groups, although the exact composition can vary: plastics 62% (including 29% elastomers), car glass, sand 16%, paint dust, rust etc. 11%, textiles, leather 6%, wood fiber, cardboard 4%, metals 1%), waste products including glass fiber reinforced carbons such as fiber optic cables or rotor blades, for example from wind turbines, can be used in the plasmalysis device according to the invention.Municipal or industrial wastewater, wood gas condensate water, grease water, cellulose water, vapor water, centrate water, press water, process water from sewage sludge treatment, landfill leachate, wash water, for example, from flue gas cleaning, oil-contaminated water, mining wastewater, wastewater from oil production (for example, from fracking, from drilling platforms), ammonia water, liquid manure (for example, pig, cattle, or poultry manure), liquid digestate, or process water obtained from these can also be used as starting materials. Instead of waste products or waste, renewable raw materials, such as biomass from plants or plant parts, or hydrogen-containing liquids such as cyclohexane, heptane, toluene, gasoline, JP-8, or diesel, can also be used as starting materials.

[0029] Particularly preferred starting materials are those which, as hydrogen-containing solids and / or liquids, comprise those which contain hydrocarbon compounds. Plasmalysis then produces solid carbon, (C(s)), where C(s) can contain various solid carbon structures, e.g., one or more carbon structures. Carbon structures can, for example, be elemental carbon particles, carbon nanotubes, fullerenes, carbon nanocones, or other carbon structures. The elemental carbon particles can, for example, have a size between 50 μm and 180 μm. Carbon layers can also form. This enables the efficient production of molecular hydrogen and elemental carbon from the starting materials. In particular, this creates a cost- and energy-efficient way of producing high-quality hydrogen and elemental carbon from waste products.

[0030] When using feedstocks containing hydrocarbons, it is particularly possible to produce lower-chain hydrocarbons, for example as additional gaseous by-products.

[0031] The plasma lysis device preferably comprises a separate high-voltage source connected to the ignition electrode. The high-voltage source can be either a high-frequency or a low-frequency voltage source. The high-voltage source is preferably a generator connected to the ignition electrode via a matching network. This enables long arcs and stabilizes the direct current plasma arc during start-up of the plasma lysis device until the outer electrode and the surrounding atmosphere are hot (e.g., 3 s). A transformer is used together with the generator as the low-frequency source. To set a suitable arc length, a transformer with at least 6 kV is preferably used.

[0032] Preferably, the ignition electrode is connected to the high-voltage source via a contacting device, for example, a wire or graphite rod. In a further embodiment, the plasma lysis device comprises a plasma gas supply line for plasma gas connected to the gas guide device.

[0033] The plasma lysis device preferably further comprises a magnetic coil arranged externally around the reaction chamber and configured to generate a magnetic field in which at least one end of the outer electrode facing away from the ignition electrode is arranged. Such a magnetic field can influence the propagation of the plasma and, in particular, prevent the plasma from flashing over onto a wall of the reaction chamber.

[0034] A feedstock inlet is preferably located below the plasma electrode assembly in the reaction chamber. This allows for uniform treatment of the feedstock. Furthermore, with gaseous feedstocks, special gas ducts allow for a residence time of the gaseous feedstock, simultaneous cooling of the reactor's inner wall, and a preferred flow velocity of more than 18 m / s at the gas outlet. This prevents sooting of the chamber and downstream systems such as pipes and heat exchangers, including a possible carbon separator.

[0035] Preferably, the reaction chamber is divided into a plasma generation zone and a fission zone, with the two zones separated by a constriction. It is particularly advantageous if the starting material feed is located in the fission zone. The separation into the two zones does not mean that fission necessarily occurs exclusively in the fission zone; rather, it can also occur partially in the plasma generation zone.

[0036] The plasmalysis device preferably has at least one gas outlet for a generated product gas, in particular for molecular hydrogen and gaseous by-products, as well as an outlet for at least one solid by-product from the reaction chamber. Solid by-products, such as solid carbon, can be present, for example, in powder form. Removing the solid by-products from the reaction chamber improves process efficiency, as they can no longer disrupt the decomposition process and ensures a continuous process. Solid by-products can, for example, be powdered carbon in various modifications if the starting material is methane. A carbon separator, for example a cyclone or filter bags, can preferably be connected to the gas outlet.This can be used to separate carbon present in the gas stream from the product gas in order to prevent clogging of subsequent membranes or adsorbers.

[0037] The plasma lysis device can have one or more membranes and / or one or more adsorbers to filter gaseous by-products from a gas stream of the gas outlet for the molecular hydrogen. These can be arranged, for example, within the gas outlet for the molecular hydrogen or at one end of the gas outlet for the molecular hydrogen. Polymer membranes, for example, can be used to separate molecular hydrogen and gaseous by-products. Ceramic materials with a large surface area and high adsorption capacity for a corresponding gaseous by-product, in particular so-called molecular sieves, can be used as adsorbers. In addition to zeolites, i.e. crystalline aluminosilicates, these can also be carbon molecular sieves. Silica gel or activated aluminum oxide, for example, can be used as adsorbers.Zeolite Socony Mobil-5 (ZSM-5), a synthetic high-silica aluminosilicate zeolite, can also be used as an adsorber. This allows gaseous byproducts to be separated from molecular hydrogen. Furthermore, the gaseous byproduct can be fed back into the reaction chamber via the feed line. This can increase the yield of molecular hydrogen.

[0038] Furthermore, the membrane or selective adsorber can also be selectively introduced into the gas outlet for the molecular hydrogen to adjust the composition of the gas stream flowing through the gas outlet for the molecular hydrogen. For example, depending on the requirements of a methane-hydrogen fuel, the methane remaining in the gas stream can be selectively mixed with the molecular hydrogen in a predetermined ratio. This can make it possible to produce a synthetic fuel, in particular a synthetic gas.

[0039] In particular, solid by-products with small particle sizes, such as elemental carbon, can also be initially discharged via the gas discharge and then separated.

[0040] In addition to such powdered solid by-products, solid or solid-liquid slags or residues may also be produced, for which an additional residual discharge may be provided in addition to the discharge. However, the slags or residues can also be conducted as by-products via a common discharge with other by-products and then separated in a further device. According to a further aspect, the invention relates to a use of the product gas produced by the plasmalysis device according to one of claims 12 to 16 or another embodiment of the plasmalysis device, in particular molecular hydrogen and / or the at least one by-product, for producing subsequent products.

[0041] Which subsequent products can be produced on the basis of the product gas produced by the plasmalysis device and / or the at least one by-product depends, among other things, on which by-products and product gases are produced.

[0042] With molecular hydrogen as the product gas, this also depends on the achieved hydrogen yield. This, in turn, depends on which elements are present in the hydrogen-containing starting material and in what concentration. For example, the hydrogen-containing gas can contain carbon in addition to hydrogen. The hydrogen-containing gas can also contain nitrogen or noble gases. Nitrogen or a noble gas can also be introduced into the reaction chamber alongside the hydrogen-containing gas, for example, via one of the additional gas supply lines.

[0043] For example, a solid or liquid starting material can contain hydrocarbons and thus carbon in addition to hydrogen. The hydrogen-containing gas can contain methane (CH4), for example.

[0044] In these cases, the at least one by-product can contain carbon structures, for example, carbon agglomerates. If methane is passed through the plasma, high-quality carbon structures can be produced. The quality of the carbon structures also depends on the parameters of the plasmalysis device during the production process. With lower energy input, for example, smaller carbon agglomerates are produced and a higher hydrogen yield is achieved. Smaller carbon agglomerates are carbon structures with smaller particle sizes of the agglomerates, for example in the range of particle sizes below 200 μm, preferably below 20 μm, which can be used, for example, as additives. With a higher energy input and, for example, a lower flow rate of the hydrogen-containing gas, higher-quality carbon structures can also be produced, for example, graphite, for example in the form of graphite pencils.In this case, however, the hydrogen yield is reduced, for example, to 20% compared to a maximum hydrogen yield. The properties of the carbon agglomerates depend, among other things, on the particle size of the primary particles and the particle size of the carbon agglomerates formed by the primary particles. As the particle size of the primary particles decreases, the viscosity increases, the dispersibility decreases, the electrical conductivity decreases, the color strength increases, and the color becomes browner. As the particle size of the carbon agglomerates decreases, the viscosity decreases, the dispersibility decreases, the electrical conductivity decreases, the color strength increases, and the color becomes browner.

[0045] Which by-products are produced with which properties depends primarily on pressure, temperature, power, frequency, and residence time of the starting material in the plasma. The power depends on the current and voltage. The average particle size, for example, depends particularly strongly on the current at a fixed voltage.

[0046] The by-product can, for example, contain over 95 wt.% carbon particles. The average particle size of the carbon agglomerates can, for example, be between 7.7 μm and 105 μm. The carbon particles can form carbon agglomerates, which together can form a porous solid. The porous solid can, for example, have pore radii between 0.18 nm and 1.7 nm. Pore volumes can, for example, be between 0.016 and 0.037 cc / g.

[0047] The by-product can be in the form of a porous solid. The by-product can have a surface area between 50 m 2 / g and 2000 m2 / g, determined by BET measurement. The by-product may contain, for example, carbon black, especially industrial carbon black. The carbon black may, for example, have a dibutyl phthalate absorption (DBPA) measured according to DIN 53601: 1978-12 between 30 and 130 ml / 100g and an iodine number of 10 to 160 mg / g.

[0048] To increase the hydrogen yield, a cascaded separation process can be carried out in which the starting material is split in several successive stages and the resulting gases and by-products are separated from each other.

[0049] In other words, the produced product gas and the at least one by-product can also be passed through several plasmalysis devices, for example with different parameters of the plasmalysis device. For example, the different plasmalysis devices can have different temperatures in the reaction chamber and / or the plasmas can have different temperatures. For example, molecular hydrogen passed through the plasma can increase the temperature and generate a hot hydrogen plasma. By changing the temperatures, different hydrogen yields can be achieved and by-products, for example with higher-quality structures, can be produced. For example, gas streams discharged from a first plasmalysis device can also be separated in such a way that only a portion of the gas streams is fed to a subsequent second plasmalysis device.This can make it possible to produce molecular hydrogen and the at least one by-product in such a way that they are optimized for specific applications or for the production of specific downstream products. For example, the at least one by-product, as a carbon structure in the form of carbon black, can have the following different ASTM grades depending on the intended application or use: N110, N115, N121, N220, N234, N330, N326, N339, N347, N375, N539, N550, or N650.

[0050] The byproducts of molecular hydrogen can include, for example, ammonia, acetylene, or synthetic gas, such as a syngas HCO mixture. The byproducts of molecular hydrogen can, in turn, be further processed into subsequent products in other applications. For example, ammonia can be used to produce fertilizer. Molecular hydrogen can also be used for energy generation, energy storage, as a fuel, or for the desulfurization of fuels.

[0051] The byproducts of molecular hydrogen can include, for example, ammonia, acetylene, or synthetic gas, such as a syngas HCO mixture. The byproducts of molecular hydrogen can, in turn, be further processed into subsequent products in other applications. For example, ammonia can be used to produce fertilizer. Molecular hydrogen can also be used for energy generation, energy storage, as a fuel, or for the desulfurization of fuels.

[0052] The subsequent products of the at least one by-product also depend on the starting material. The at least one by-product produced alongside the molecular hydrogen depends on various parameters of the plasmalysis device during the production process. By adjusting the parameters of the plasmalysis device, a surface size and clustering of carbon chains can be adjusted, among other things, in order to produce different carbon structures, for example different types of soot. The carbon structures can also be post-treated, for example, with a plasma, for example the plasma of the plasmalysis device, in order to produce new crystalline structures. For example, several plasmalysis devices can be arranged in series so that the carbon structures produced in the first plasmalysis device can be post-treated in a second plasmalysis device.Therefore, different carbon structures can be produced in different forms. The parameters of the plasmalysis device can be optimized during the manufacturing process, for example, to produce a specific by-product, e.g., with a specific carbon structure that is optimized for a specific application or further processing into a subsequent product.

[0053] Downstream products that can be made from the carbon structures or to which the carbon structures can be added as an additive can include, for example, compostable products such as coffee capsules and containers, or also animal feed additives, ceramics, improved manure, activated carbon for wastewater treatment, coal for the extraction of phosphorus and other chemical feedstocks in sewage sludge, improved soil for improved nutrient storage, carbon binder mixtures for example as a replacement for building materials or plastics, carbon polymer mixtures, carbon biopolymers, carbon silicates, coke, asphalt mixtures, cement mixtures, concrete mixtures, tires, paints, varnishes, black surfaces, batteries, coatings, toner, ink, conductive ink, mechanical rubber products, conveyor belts, casings, closures, plastics, cables and containers.Certain derived products can be used, for example, for insulation, filtration, packaging or lightweight construction.

[0054] Another downstream product could be, for example, a methane-carbon dioxide mixture (CH4 + CO2), which can be used as a precursor for the Fischer-Tropsch process to produce kerosene. Downstream products can also include synthetic fuels, which can be synthesized from the gas streams produced by the plasmalysis device. Synthesis can also be carried out in the plasmalysis device itself, for example, at 50 bar. Fission steps can also be combined with synthesis steps.

[0055] Depending on the starting material, slag and residues can also be reused in subsequent products; for example, they can be used as aggregates in asphalt. According to a further aspect, the invention relates to the use of molecular hydrogen produced in a plasmalysis device according to one of claims 12 to 16 or another embodiment of the plasmalysis device for the following applications: as fuel, for producing a hydrogen combustion product, as a propulsion medium, for operating a hydrogen-powered vehicle, for mixing with liquefied gas, for mixing with liquefied natural gas (LNG), for mixing with liquid biomethane (LBM).Liquefied biomethane), for mixing with natural gas, for mixing with methane, for producing synthesis gas, for producing synthetic fuel, for producing ammonia that can be used to produce fertilizer, for refining crude oil, for hydrogenating chemical compounds, for operating a hydrogen turbine, for operating a fuel cell, for operating a combined heat and power (CHP) plant, for operating a cogeneration plant, for generating energy using a fuel cell, for generating energy and / or heat using a combined heat and power plant, in a gas separation plant, in a gas compression plant, for producing synthetic raw materials, for storing energy, for generating heat, for generating energy.

[0056] Protection is only claimed for molecular hydrogen actually produced with the plasmalysis device. In other words, this applies precisely to the situation in which the molecular hydrogen is produced in the plasmalysis device and then utilized, for example, by being used for a specific application.

[0057] According to a further aspect, the invention relates to the use of by-products produced in a plasmalysis device according to one of claims 12 to 16 or another embodiment of the plasmalysis device for the following applications: as a reducing agent in the production of steel, as a fuel, as an adsorbent, for example in chemistry, medicine, drinking water treatment, wastewater treatment, ventilation technology or air conditioning technology, as a support material for catalysts for heterogeneous catalysis, as a base material for the production of carbon structures, - as an additive for the production of asphalt, as an additive for the production of cement, as an additive for the production of concrete, as an ingredient of a thermally conductive agent, for example a thermally conductive paste, as activated carbon for wastewater treatment, - as a feed additive, as an additive to a binder, as an additive to soil for improved nutrient storage,as coal for the extraction of phosphorus and other chemical raw materials in sewage sludge, - as an additive in building materials, as an additive in plastics, for insulation, for filtration, for packaging, for lightweight construction.

[0058] The by-product can also be used, for example, in the steel industry, for example, in blast furnaces or cupolas. Protection is only claimed for by-products actually produced with the plasmalysis device. In other words, this applies precisely to the situation in which the by-product is produced in the plasmalysis device and then utilized, for example, by being used for a specific application.

[0059] Further embodiments of the device and method are described below with reference to the drawings. They show:

[0060] Fig. 1 A schematic representation of an embodiment of a plasma electrode arrangement according to the first aspect of the invention in a sectional view;

[0061] Fig. 2 A schematic representation of the embodiment of a plasma electrode arrangement according to Fig. 1 in a perspective view;

[0062] Fig. 3 A schematic representation of an embodiment of a plasma lysis device according to the second aspect of the invention.

[0063] In the following description of embodiments, similar reference numerals generally refer to similar elements.

[0064] Fig. 1 shows a schematic representation of an embodiment of a plasma electrode assembly 1000. This assembly comprises a cylindrical hollow outer electrode 200, an ignition electrode 100, and an inner electrode (not shown here). The inner electrode is arranged at a distance within the outer electrode 200 and the ignition electrode 100 and is preferably also hollow. The inner electrode forms a counter electrode to the outer electrode and the ignition electrode.

[0065] The ignition electrode 100 is ring-shaped and electrically insulated from and spaced from the outer electrode 200. The ignition electrode 100 can also be connected to a high-voltage source, here via a contacting device 120. In the embodiment shown, the ignition electrode 100 is flattened on a side facing the outer electrode 200, and its thickness decreases from a side facing away from the outer electrode 200 to a side facing the outer electrode. The ignition electrode 100 is therefore essentially designed as a hollow truncated cone, to which a fastening region 110 adjoins. The ignition electrode is mechanically connected to the outer electrode 200 via the fastening region 110 via insulating spacers 210. The ignition electrode 100, outer electrode 200, and inner electrode 300 are preferably made of graphite here.

[0066] Two gas guide rings 410 of a gas guide device 400 are arranged above the ignition electrode 100 via additional insulating spacers. In the embodiment shown, the gas guide rings 410, and with them the gas guide device 400, have channels for guiding gas. These are discussed in more detail in Fig. 2. Here, the gas guide rings 410 are arranged in a housing 450 comprising a ceramic tube.

[0067] The plasma electrode assembly 1000 further comprises a bayonet connection 500 for connection to a bayonet socket in an opening of a reaction chamber. The bayonet connection 500 has bayonet pins 510 for engaging corresponding openings in the bayonet socket. The outer electrode 200 and the ignition electrode 100 are mechanically connected to the bayonet connection 500. In the embodiment shown, the outer electrode extends within the bayonet connection and, from there, further into the reaction chamber, which is only indicated here.

[0068] Fig. 2 additionally shows, in a schematic representation, the exemplary embodiment of a plasma electrode arrangement 1000 according to Fig. 1 in a perspective view. Here, the channels 420 of the gas guide device 400 are particularly clearly visible, which are arranged concentrically around an inner opening through which the inner electrode can be guided.

[0069] Fig. 3 shows a schematic representation of an embodiment of a plasmalysis device 2000 according to the second aspect of the invention. The plasmalysis device 2000 for splitting a starting material into at least one product gas and at least one by-product comprises a plasma electrode arrangement 1000. This is located at least partially in a reaction chamber 2005, which is divided here into a plasma generation region 2010 and a splitting region 2020, with both regions separated from each other by a constriction 2015. The separation into two regions does not mean that splitting necessarily takes place exclusively in the splitting region; rather, it can also occur partially in the plasma generation region.

[0070] The plasma electrode assembly 1000 here comprises an ignition electrode 100, an outer electrode 200 and an inner electrode 300. Furthermore, it comprises a gas guiding device 400. A plasma gas can be supplied via the plasma gas supply line 2800, which is connected to the gas guiding device.

[0071] A starting material feed 2100 is arranged here in the cleavage region 2020, i.e. below the plasma electrode arrangement 1000.

[0072] The plasma lysis device 2000 further comprises an alternating current source 2400 connected to the outer electrode 200. In the illustrated embodiment, the ignition electrode 100 is connected to a separate high-voltage source 2300. The high-voltage source 2300 can be either a high-frequency or a low-frequency voltage source.

[0073] The plasma lysis device 2000 further comprises a magnetic coil 2600, which is arranged outside the reaction chamber 2005 and is designed to generate a magnetic field in which at least one end of the outer electrode 200 facing away from the ignition electrode 100 is arranged.

[0074] The plasma lysis device 2000 also has a gas discharge line 2200 for a generated product gas, in particular for molecular hydrogen and gaseous by-products, as well as a discharge line 2700 for at least one solid by-product from the reaction chamber.

[0075] The plasma electrode assembly 1000 has an electrode changing system 2500 comprising a plurality of inner electrodes 300 in a drum arrangement of a revolver system. The electrode changing system 2500 is configured to lower exactly one inner electrode into an interior of the outer electrode 200 and, after a predetermined time or in response to a control signal, to raise the lowered inner electrode 300, rotate the drum by at least one position, and lower another inner electrode into the interior.

[0076] 100 ignition electrodes

[0077] 110 Mounting area

[0078] 120 Contacting device 200 Outer electrode

[0079] 210 spacers

[0080] 300 internal electrode

[0081] 400 Gas guide device

[0082] 410 gas guide rings 420 channels

[0083] 450 housings

[0084] 500 bayonet connection

[0085] 510 bayonet pins

[0086] 1000 Plasma electrode assembly 2000 Plasma lysis device

[0087] 2005 Reaction chamber

[0088] 2010 Plasma generation area

[0089] 2015 narrowing 2020 cleavage area

[0090] 2100 raw material feed

[0091] 2200 gas discharge

[0092] 2300 high voltage source 2400 alternating current source

[0093] 2500 electrode exchange system

[0094] 2600 solenoid coil

[0095] 2700 Derivation

[0096] 2800 plasma gas supply line

Claims

Claims 1. Plasma electrode arrangement (1000) comprising a cylindrical hollow outer electrode (200), an annular ignition electrode (100) electrically insulated from and spaced from the outer electrode (200), and an inner electrode (300) spaced from the outer electrode (200) and the ignition electrode (100), wherein the ignition electrode (100) is connectable to a high-voltage source (2300).

2. Plasma electrode arrangement (1000) according to claim 1, wherein the ignition electrode (100) is flattened on a side facing the outer electrode (200).

3. Plasma electrode arrangement (1000) according to one of the preceding claims, wherein a thickness of the ignition electrode (100) decreases from a side facing away from the outer electrode (200) to a side facing the outer electrode.

4. Plasma electrode arrangement (1000) according to one of the preceding claims, wherein the ignition electrode (100) is formed substantially as a hollow truncated cone.

5. Plasma electrode arrangement (1000) according to one of the preceding claims, wherein the ignition electrode (100) has a fastening region (110) with which it is mechanically connected to the outer electrode (200) via insulating spacers (210).

6. Plasma electrode arrangement (1000) according to one of the preceding claims, in which an ignition gap between the ignition and inner electrode (300) has a width in the range of 4 to 20 mm.

7. Plasma electrode arrangement (1000) according to one of the preceding claims, in which a plasma gap between the outer and inner electrodes (300) has a width of more than 20 mm.

8. Plasma electrode arrangement (1000) according to one of the preceding claims, wherein at least the outer electrode (200), the ignition electrode (100) or the inner electrode (300) comprises graphite or consists of graphite.

9. Plasma electrode arrangement (1000) according to one of the preceding claims, further comprising a side of the ignition electrode facing away from the outer electrode (200) and a gas guiding device (400) arranged at a distance therefrom, wherein the gas guiding device comprises channels (420) and / or grooves for guiding gas and the channels and / or grooves are arranged in particular concentrically.

10. Plasma electrode arrangement (1000) according to one of the preceding claims, wherein the inner electrode (300) is hollow.

11. Plasma electrode arrangement (1000) according to one of the preceding claims, comprising an electrode changing system (2500) comprising a plurality of inner electrodes (300) in a drum arrangement of a turret system, wherein the electrode changing system is designed to lower exactly one inner electrode into an interior of the outer electrode (200) and, after a predetermined time or in response to a control signal, to raise the lowered inner electrode, to rotate the drum by at least one further position and to lower another inner electrode into the interior.

12. Plasma lysis device (2000) for splitting a starting material into at least one product gas and at least one by-product, comprising a plasma electrode arrangement (1000) according to one of the preceding claims, at least partially arranged in a reaction chamber (2005) and at least one starting material feed (2100) in the reaction chamber, and a direct current source (2400) connected to the outer electrode (200).

13. Plasma lysis device (2000) according to claim 12, further comprising a separate high voltage source (2300) connected to the ignition electrode (100).

14. Plasmalysis device (2000) according to one of claims 12 or 13, further comprising a plasma gas supply line (2800) for plasma gas connected to the gas guide device.

15. Plasma lysis device (2000) according to one of claims 12 to 14, comprising a magnetic coil (2600) which is arranged outside the reaction chamber (2005) and is designed to generate a magnetic field in which at least one end of the outer electrode (200) facing away from the ignition electrode (100) is arranged.

16. Plasma lysis device (2000) according to one of claims 12 to 15, wherein the at least one starting material feed (2100) is arranged in the reaction space below the plasma electrode arrangement (1000).

17. Use of the product gas produced in a plasma lysis device (2000) according to one of claims 12 to 16, in particular molecular hydrogen, and / or at least one by-product for producing subsequent products.

18. Use of molecular hydrogen produced in a plasmalysis device according to any one of claims 12 to 16 for the following applications: as a fuel, for producing a hydrogen combustion product, as a propulsion agent, for operating a hydrogen-powered vehicle, for mixing with liquefied petroleum gas, for mixing with liquefied natural gas, for mixing with liquid biomethane, for mixing with natural gas, for mixing with methane, for producing synthesis gas, for producing synthetic fuel, for producing ammonia, for refining petroleum, for hydrogenating chemical compounds, for operating a hydrogen turbine, for operating a fuel cell, for operating a combined heat and power plant, for operating a cogeneration plant, for generating energy by means of a fuel cell, - for generating energy and / or heat by means of a combined heat and power plant, in a gas separation plant, in a gas compression plant, for producing synthetic raw materials, for storing energy, - for generating heat, for generating energy.

19. Use of by-product produced in a plasmalysis device according to any one of claims 12 to 16 for the following applications: as a reducing agent in the production of steel, - as a fuel, as an adsorbent, as a support material for catalysts for heterogeneous catalysis, as a base material for the production of carbon structures, as an additive for the production of asphalt, as an additive for the production of cement, as an additive for the production of concrete, as an ingredient in a heat transfer agent, as activated carbon for wastewater treatment, - as a feed additive, as an additive to a binder, as an additive to soil for improved nutrient storage, as coal for the extraction of phosphorus and other basic chemicals in sewage sludge, - as an additive in building materials, as an additive in plastics, for insulation, for filtration, for packaging, - for lightweight construction.

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