CH720593A1 - DISSOCIATION PROCESS AND SYSTEM FOR THE DISSOCIATION OF CARBON DIOXIDE AND/OR METHANE - Google Patents

Abstract

The invention relates to a dissociation method and a dissociation system for dissociating carbon dioxide and/or methane components using a microwave plasma. A microwave plasma environment in the form of a non-thermal plasma is provided in a reactor chamber (1), which is realized as a pulsed microwave plasma by applying microwave pulses to the plasma. Carbon dioxide and/or methane components are introduced into the reactor chamber (1). The non-thermal, pulsed microwave plasma (P) is defined such that the carbon dioxide and/or methane components are dissociated into dissociation products, which are preferably selected from the group of carbon monoxide, hydrocarbons, hydrogen, solid carbon, synthesis gas, fuels and/or oxygenates.

Description

[0001] The invention relates to a dissociation method and a dissociation system for dissociating carbon dioxide and/or methane components using a microwave plasma treatment.

[0002] Efforts to dissociate carbon dioxide (CO2) or methane (CH4) using various methods such as catalytic conversion, photocatalytic or photochemical processes, electrocatalytic or electrochemical processes, enzymatic or biomedical processes have been extensively studied. Methods using plasma treatment have been found to be extremely effective.

[0003] For example, in US 9987611 B1, a non-thermal plasma environment is used to dissociate a hydrocarbon material. A vessel is provided in communication with a first conduit, a second conduit and a microwave radiation source. A first stream of a hydrocarbon precursor material and a second stream of a plasma-forming material are injected into the vessel through the first conduit and the second conduit, respectively. The microwave radiation source exposes the hydrocarbon precursor material and the plasma-forming material in the vessel to microwave radiation. The exposure selectively converts the plasma-forming material into non-thermal plasma. The non-thermal plasma forms one or more streamers. Within the vessel, the hydrocarbon precursor material is exposed to the streamers. Exposing the hydrocarbon precursor material to both microwave radiation and the streamers formed selectively converts the hydrocarbon precursor material into carbon-enriched materials and hydrogen-enriched materials.

[0004] In "Non-thermal plasma technology for the conversion of CO2", Bryony-Ashford, Xin Tu, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK, carbon dioxide conversion methods using a non-thermal plasma environment are discussed. Compared to other processes, this is a simple and rapid process: the plasma has the potential to allow thermodynamically unfavourable chemical reactions to occur at ambient conditions. Non-thermal plasma can operate at atmospheric pressure while still producing highly active species and electrons.

[0005] The main challenge associated with the use of non-thermal plasma for carbon dioxide is overcoming the high stability of the carbon dioxide molecule since a high energy input is required to break the C=O double bond and dissociate the molecule. There is a trade-off between energy efficiency and carbon dioxide conversion when using plasma processes since the conversion increases as the energy input is increased, which in turn causes a decrease in the energy efficiency of the carbon dioxide dissociation process. To address this challenge and facilitate the conversion process in the non-thermal plasma environment, it is proposed to add catalysts.

[0006] For example, in WO 2010/033530 A3, ammonia (NH3) is produced by passing nitrogen (N2), carbon monoxide (CO) and water (H2O) into a non-thermal plasma in the presence of a catalyst, the catalyst being effective to promote the dissociation of N2, CO and water to form reactants which in turn react to form ammonia and methane. A reactive hydrogen ion or free radical is produced by the process comprising passing water through a non-thermal plasma in the presence of a catalyst, the catalyst being effective to promote the dissociation of water.

[0007] However, in plasma catalysis, the chemistry becomes even more complex due to the interactions between plasma and catalyst. The number of different catalysts that can be used in plasma processes, together with variations in catalyst preparation methods, loading amount, pretreatment, etc., make it difficult to use a "universal solution".

[0008] It is an object of the invention to provide a dissociation method and a dissociation system for dissociating carbon dioxide and/or methane components which are cost and energy efficient, simple in construction and easy to carry out and increase a yield of dissociation products.

[0009] These and other objects which will become apparent from the description below can be achieved by a dissociation method and a dissociation system as set out in the appended independent claims. Preferred embodiments and variants are defined in the dependent claims.

[0010] A dissociation method for dissociating carbon dioxide and/or methane components using a microwave plasma treatment according to the invention comprises the following steps. In a reactor chamber, a microwave plasma environment is achieved by irradiating a plasma material using microwave radiation. Carbon dioxide and/or methane components are introduced into the reactor chamber and into the microwave plasma environment. The microwave plasma environment is a non-thermal plasma which is realized as a pulsed microwave plasma by applying microwave pulses to the plasma material. The non-thermal, pulsed microwave plasma is defined to dissociate the carbon dioxide and/or methane components into dissociation products. Advantageously, the non-thermal, pulsed microwave plasma is defined such that the dissociation products are selected from the group of carbon monoxide, hydrocarbons, hydrogen, solid carbon, synthesis gas, fuels and/or oxygenates.

[0011] A dissociation system for carrying out the dissociation process comprises at least one reactor chamber for receiving the non-thermal pulsed microwave plasma and at least one microwave generator and plasma applicator for generating the non-thermal pulsed microwave plasma in the reactor chamber. The reactor chamber comprises at least one inlet for injecting the carbon dioxide and/or methane components into the reactor chamber and exposing the components to the non-thermal pulsed microwave plasma, and at least one outlet for extracting dissociation products from the reactor chamber.

[0012] For example, carbon dioxide (CO2) or methane (CH4) can be used as a plasma material. The material is treated by the microwave generator and plasma applicator to thermalize only the electrons of the material. The resulting plasma is not in thermodynamic equilibrium because the temperature of the electron is much hotter than the temperature of the heavy particles of the material, i.e. ions and neutrals.

[0013] The properties of the non-thermal pulsed microwave plasma are defined to meet specific requirements to achieve specific dissociation products. For example, the different dissociation products in the form of carbon monoxide, hydrocarbons, hydrogen, synthesis gas, fuels and/or oxygenates may require different energies for dissociation. In addition, some plasma materials are better suited to some dissociation products than others. For example, carbon dioxide dissociates at 1800 C° to 2200 C° to carbon monoxide and oxygen. At higher temperatures, carbon dioxide forms carbon nanomaterials and oxygen. At temperatures below 1500 C°, methane forms short-chain hydrocarbons (C2H6, C2H2, C3H8, C3H6, etc.) and hydrogen. At higher temperatures, the selectivity of short-chain hydrocarbons will decrease and the selectivity of hydrogen and carbon-based materials will increase. When carbon dioxide and methane are used together, the product formed is water (H2O) along with short chain hydrocarbons and carbon materials. As mentioned above, the addition of nitrogen (N2) and water results in carbon monoxide (and hence carbon dioxide, since carbon dioxide dissociates to carbon monoxide) and the production of ammonia (NH3). Preferably, a microwave frequency and/or microwave pulse width is selected according to dissociation parameters of the selected dissociation products (examples needed). For example, for carbon dioxide, a reaction time of 50 to 250 milliseconds can be used. The microwave frequency and microwave pulses define the properties of the non-thermal, pulsed microwave plasma for a specific dissociation product. For example, the microwave frequency and microwave pulse are different for carbon monoxide, hydrocarbons, hydrogen, syngas, fuels and oxygenates; pulse lengths of 250 ms allow dissociation of CO2 to be completed. The combination of selective microwave frequency and suitable pulse widths enables efficient conversion and high product yield for different reagent mixtures.

[0014] Advantageously, the non-thermal pulsed microwave plasma stimulates vibrational excitation modes in the carbon dioxide (CO2) and/or methane (CH4) components. For the molecular dissociation of carbon dioxide or methane, vibrational excitation results in a more efficient process than non-vibrational modes. The process is faster and requires less energy. The non-thermal pulsed microwave plasma is able to effectively stimulate the vibrational modes and is ideal for converting CO2 or CH4 and has some of the desired properties of high electron number density and thermal non-equilibrium between electron temperature and heavy particle gas temperature.

[0015] In a variant of the dissociation process, the non-thermal pulsed microwave plasma is generated by microwave radiation at frequencies between 300 MHz and 40,000 MHz. For example, lower frequencies within this range are recommended for carbon dioxide. Higher frequencies within this range are recommended for methane.

[0016] In a further variant of the dissociation process according to the invention, a controlled atmosphere is realized in the reactor chamber, which varies a pressure in the reactor chamber to modify a plasma temperature depending on the selected dissociation product. For example, as mentioned above, carbon dioxide forms carbon nanomaterials and oxygen at temperatures higher than 2200°C. Furthermore, the controlled atmosphere can be defined as a vacuum atmosphere that creates a negative pressure in the reactor chamber. Defining the controlled atmosphere as needed for specific input components and/or specific dissociation products also supports the definition of the conditions for non-thermal, pulsed microwave plasma for dissociation of the carbon dioxide and/or methane components.

[0017] In yet another variant of the dissociation process according to the invention, the controlled atmosphere can be realized as a reactive atmosphere in the reactor chamber in order to modify the products formed during the dissociation.

[0018] The reactive atmosphere can be generated by reactive gases such as hydrogen, steam, carbon monoxide, methane, benzene or a mixture of reactive gases as contained in synthesis gas. Preferably, the synthesis gas formed during the process is partially recycled through the reactor to promote alternative reactions or to increase the yield of liquid or gaseous target products. The reactive atmosphere can be determined according to the input products and/or starting products. Therefore, it can vary depending on what type of dissociation product is to be produced by the dissociation process.

[0019] In another variant of the dissociation process according to the invention, volatile components present after passing the input components through the plasma environment are extracted from the reactor chamber and subjected to fractional condensation for the sequential extraction of dissociation products using a fractional condensation unit of the dissociation system. For example, the volatile components form a vapor mixture which is cooled in steps, causing sequential condensation of different dissociation products.

[0020] The fractional condensation process includes the steps of rapidly extracting volatiles to reduce the residence time of the volatiles in the reactor chamber. Next, the volatile gases are condensed into various fractionated components. Optionally, the fractionated components are subjected to further fractional condensation to isolate at least one more valuable chemical.

[0021] In an advantageous variant of the dissociation process according to the invention, low microwave energy is continuously applied to the microwave plasma between high microwave energy pulses. The low microwave energy is, for example, in the range of 300 MHZ to 40 GHZ. While the non-thermal, pulsed microwave plasma oscillates in pulses of energy, the application of low microwave energy maintains a plasma with continuous properties. The use of a continuous supply of low microwaves to maintain the plasma during the intervals between the high energy microwave pulses helps to define a controlled atmosphere for the dissociation process. The supply of low energy microwaves can be provided by the microwave generator that generates the microwave pulses. That is, the microwave generator produces a constant output of low energy microwaves with the pulses superimposed thereon. Alternatively, a second microwave generator can be provided that operates constantly at the same microwave frequency, or even at a different frequency than the pulsed microwave source.

[0022] In a further variant of the dissociation process according to the invention, carbon dioxide is dissociated with methane in non-thermal, pulsed microwave plasma by dry reforming. Dry reforming produces synthesis gas, a mixture of hydrogen and carbon monoxide, from the reaction of carbon dioxide with methane with the aid of noble metal catalysts such as Ni or Ni alloys. Dry reforming of methane using CO2 has the advantage of using two greenhouse gases in a single process.

[0023] Advantageously, the dissociation system is designed such that gas components not dissociated in the non-thermal pulsed microwave plasma can be recycled through the non-thermal pulsed microwave plasma for further treatment. Also, dissociation products produced by the dissociation process can be recycled into the process, for example, to create a reactive atmosphere to facilitate the dissociation process.

[0024] The dissociation system according to the invention may comprise a control unit for generating the non-thermal, pulsed microwave plasma in the reactor chamber comprising a microwave frequency and/or microwave pulse width modified according to dissociation parameters of the selected dissociation products. The control unit comprises a microwave radiation controller for generating a pulsed microwave plasma in the reactor chamber comprising pulses of microwave energy. The pulsed microwave plasma then stimulates vibrational excitation modes in the input products. The microwave radiation controls the application of microwave radiation at frequencies between 300 MHz and 40000 MHz. Further, the control unit may comprise an atmosphere control unit for controlling the atmosphere in the reactor chamber. For example, the atmosphere control unit controls the application of a pressure in the chamber or the addition of a reactive gas to define a reactive atmosphere in the chamber. In addition, the control unit can monitor a temperature in the reactor chamber and adjust the temperature if needed for the dissociation process of an input product or to achieve a selected output product.

[0025] In an advantageous embodiment of the dissociation system according to the invention, the non-thermal, pulsed microwave plasma is accommodated in a plasma tube which extends through at least one reactor chamber. Preferably, the plasma tube then extends through a first reactor chamber and a second reactor chamber. The input products are exposed to the non-thermal, pulsed microwave plasma in the plasma tube. Dissociated products migrate through the plasma tube and are extracted through the outlets in the plasma tube or in the reaction chamber.

[0026] In a further embodiment of the dissociation system according to the invention, a pump is connected to the reactor chamber or plasma tube receiving the non-thermal, pulsed microwave plasma for regulating a pressure in the reactor chamber or plasma tube. The pump can be controlled by the control unit to generate a pressure in the chamber. Furthermore, the pump can discharge the dissociation products into a gas storage device connected to the outlet.

[0027] Advantageously, the dissociation system includes microwave plasma generators with solid state shaping, which allows the amplitude and shape of the microwave pulses to be precisely controlled, which in turn allows specific control of the plasma temperature. Active impedance matching circuits can ensure reliable plasma ignition and efficient power transfer during operation. The active impedance matching circuit can be placed between the microwave plasma generator and the plasma chamber. It continuously adjusts to match the load impedance presented by the plasma to the microwave transmission line, thereby ensuring maximum power transfer to the plasma under all plasma conditions.

[0028] In summary, the present invention relates to a pulsed non-thermal, non-equilibrium microwave plasma system for the dissociation and/or utilization of carbon dioxide and/or methane.

[0029] The process is preferably carried out under vacuum or controlled gas atmosphere and includes a fractional condensation process and system as part thereof. The microwave radiation used is in the range of 300 MHz to about 40 GHz. The pulsed non-thermal, non-equilibrium microwave plasma system can be used with or without a catalyst, where the catalyst can be in the plasma or part of the post-plasma process.

[0030] The dissociation process is based on carbon dioxide dissociation: 2CO2→ 2CO + O2 and methane dissociation: CH4→ C+ H4. The dissociation process is suitable for the dry reforming of carbon dioxide with methane: CO2+ CH4→ 2CO + 2H2 ΔHo=247 kJ/mol

[0031] Preferred embodiments of the invention are described in the accompanying drawings, which may illustrate the principles of the invention but are not intended to limit the scope of the invention. The drawings illustrate: Fig. 1 is a schematic diagram of a first dissociation system according to the invention, and Fig. 2 is a schematic diagram of a second dissociation system according to the invention.

[0032] Two exemplary embodiments of a dissociation system according to the invention are described below, which are suitable for carrying out a dissociation process for dissociating carbon dioxide and/or methane components using a microwave plasma treatment according to the invention. Features disclosed for one of the embodiments can also be applied to the other embodiment without the need for further development, which will be apparent to a person skilled in the art. A repetitive description of such features is therefore avoided for the sake of clarity.

[0033] Figure 1 illustrates a first embodiment of a dissociation system for carrying out the dissociation method for dissociating carbon dioxide and/or methane components according to the invention.

[0034] The dissociation system comprises a reaction chamber 1 for receiving a microwave plasma environment, a microwave generator 2 and a plasma applicator in the form of a plasma tube 3 for generating a non-thermal, pulsed microwave plasma P in the reactor chamber 1. At an inlet end of the plasma tube 3, three inlets 4 are provided for injecting carbon dioxide and/or methane components and other gas reagents into the reaction chamber 1. The inlet end of the plasma tube is located in front of the intersection of the plasma tube with the reactor chamber 1, wherein the inlet products interact with the non-thermal, pulsed microwave plasma. An outlet end of the plasma tube 3, located downstream of the reactor chamber 1, comprises an outlet 5 for extracting dissociation products from the reaction chamber. The outlet 5 is designed as an outlet pipeline, wherein a cooling unit 6 and a pump unit 7 are arranged in the pipeline. The outlet 5 terminates in a storage unit 8 for storing dissociation products generated by the dissociation process. A connecting pipe 9 connects the storage unit 8 to the inlet end of the plasma tube 3. Dissociation products or inlet products that do not dissociate can be fed back into the plasma tube 3 into the dissociation process through the connecting pipe 9. An alternative connecting pipe 9' connects the storage unit 8 to the plasma tube so that dissociation products can be fed directly into the plasma tube 3 and the reactor chamber 1. Advantageously, the plasma tube 3 runs through the reactor chamber 1 at a location where the microwave field is concentrated.

[0035] The microwave generator 2 injects pulsed microwave fields into the plasma reactor chamber 1 and ionizes a plasma material in the plasma tube 3. The inlet gases carbon dioxide and methane and other gases are mixed and injected into the plasma reactor as reactant gases in the correct ratios. The Gibbs energy of CO2 favors the production of CO and O2<->/O2, while CH4 dissociates into solid carbon structures such as soot and/or carbon nanomaterials; carbon-based materials; short-chain hydrocarbons (C2H6, C2H2, C3H8, C3H6, etc.) and H2 when dissociated separately at mild temperatures. When carbon dioxide and methane are simultaneously exposed to the plasma, then water (H2O) is formed as a product together with solid carbon structures such as soot and/or carbon nanomaterials and short-chain hydrocarbons.

[0036] These carbon-based materials may include oxygen-containing short-chain hydrocarbons, such as formaldehyde (CH2O), acetaldehyde and ethylene oxide (C2H4O), methanol (CH3OH), etc. This is due to the oxygen radical (O2<->) from carbon dioxide dissociation reacting with an unsaturated hydrocarbon from methane. Therefore, when carbon dioxide is the limiting reagent, less oxygen-containing hydrocarbons and water are expected. The following relationship can be expected: CH4< 20 mol% ~ solid carbon materials; mainly oxygen-containing hydrocarbons and water; small amounts of CO; short-chain hydrocarbons and hydrogen. CH4> 60 mol% ~ solid carbon materials; mainly short-chain hydrocarbons and hydrogen with small amounts of water and CO.

[0037] In addition to the reaction gases for producing dissociation products, a reactive medium, e.g. hydrogen or an inert carrier gas such as argon, may also be injected into the plasma reactor through the inlets 4. Such reactive media may be used to create and define a controlled atmosphere and/or a reactive atmosphere in the reactor chamber 1. The cooling unit 6 tempers the dissociation product gases. The pump unit 7 regulates the pressure in the plasma tube 3 and delivers the dissociation product gases to the gas storage unit 8. The pump unit 7 may regulate the pressure in the plasma tube 3 to subatmospheric levels to create a low temperature plasma or to higher pressures to enable higher plasma temperatures.

[0038] The gas storage unit 8 may include a membrane filter or other filtering device to separate different gas species of the dissociation products. Unreacted gas may then be recycled through the non-thermal pulsed microwave plasma P via the connecting tubes 9 or 9' to increase the yield of the dissociation process. The final dissociation products may be extracted from the storage unit 8 for further use or processing.

[0039] In a variation of this example, the microwave generator 2 may be configured to generate microwave pulses superimposed on a smaller continuous microwave waveform. The purpose of the continuous waveform is to assist in maintaining the non-thermal, pulsed microwave plasma P between pulses.

[0040] In another variation of the illustrated dissociation system, all or some of the inlet reaction gases may be injected into the non-thermal, pulsed microwave plasma P at some distance along the length of the plasma or plasma tube 3. Introducing the inlet products along the length of the plasma modifies the exposure time of the gases into the plasma. To this end, plasma tube 3 may have multiple inlet ports (not shown) spaced apart at different distances along plasma tube 3 in the flow direction. Depending on the required exposure time of an inlet gas to the defined non-thermal, pulsed microwave plasma present in reactor chamber 1, a specific inlet port may be chosen that corresponds to a desired exposure time when the inlet gas enters the production flow. Furthermore, these inlet openings can be used to introduce a quenching gas to rapidly cool the dissociation products and other gases exiting the reactor chamber 1.

[0041] Figure 2 illustrates a second embodiment of a dissociation system for carrying out the dissociation process for dissociating carbon dioxide and/or methane components according to the invention. In contrast to the first embodiment, the dissociation system comprises the first reactor chamber 1 and the first microwave generator 2 and additionally a second reactor chamber 1' and a second microwave generator 2'. The plasma tube 3 extends in the flow direction of the inlet gases through the first reactor chamber 1 and then through the second reactor chamber 1'. The dissociation products and reaction gases leave the plasma tube 3 through an outlet end of the plasma tube, as described for the first embodiment shown in Figure 1. Between the microwave generator 2 and 2' and the respective reactor chamber 1 and 1', a first and a second waveguide filter 10 and 10' are provided.

[0042] As mentioned, the second embodiment includes all the features of the first embodiment, but introduces the second microwave generator 2' as a second microwave power for the non-thermal, pulsed microwave plasma P. The first microwave generator 2 serves as a continuous microwave source connected to the reactor chamber 1 and the plasma tube 3, wherein the inlet gases are ionized. The second microwave generator 2' is similarly connected to the second reactor chamber 1', wherein the plasma tube 3 passes through both plasma reactors. The second microwave generator 2' serves as a pulsed microwave source to generate the non-thermal, pulsed microwave plasma P in the plasma tube 3.

[0043] The microwave waveguide filters 10 and 10' are used between the second microwave generators and the reactor chambers to prevent energy from the first microwave generator 2 from reaching the microwave generator 2' and negatively affecting its operation, and vice versa.

[0044] In a variation of the second embodiment, the two microwave generators may be attached to the same reactor chamber, superimposing their microwave outputs and increasing the power density in the non-thermal pulsed microwave plasma.

[0045] The dissociation process of the invention may include a catalytic process, wherein the carbon dioxide and/or methane components and/or intermediates are subjected to a catalytic process in non-thermal, pulsed microwave plasma and/or as part of a post-plasma process. The catalytic process may be a catalytic conversion, a photocatalytic or photochemical process, electrocatalytic or electrochemical process, enzymatic or biomedical process, as known in the art.

[0046] Carbon dioxide, methane and other greenhouse gases are a negative byproduct of fossil fuel combustion and contribute to global warming. The dissociation process of the present invention plays an important role in climate change mitigation strategies. The dissociation process is energy efficient due to the low energy consumption to generate the non-thermal pulsed microwave plasma that processes the input products at a lower temperature of a plasma in equilibrium. Furthermore, the process allows for increased throughput of greenhouse gases.

list of reference numbers

[0047] 1, 1' reactor chamber 2, 2' microwave generator 3 plasma tube 4 inlet 5 outlet 6 cooling unit 7 pump unit 8 storage unit 9, 9' connecting tube 10, 10' waveguide filter

Claims (15)

1. Dissociation process for dissociating carbon dioxide and/or methane components using a microwave plasma treatment, comprising the following steps: - providing a microwave plasma environment in a reactor chamber (1), and - introducing carbon dioxide and/or methane components into the reactor chamber (1), wherein the microwave plasma environment is a non-thermal plasma realized as a pulsed microwave plasma by applying microwave pulses to the plasma, and wherein the non-thermal, pulsed microwave plasma (P) is defined to dissociate the carbon dioxide and/or methane components into dissociation products, preferably selected from the group of carbon monoxide, hydrocarbons, hydrogen, solid carbon, synthesis gas, fuels and/or oxygenates. 2. Dissociation process according to claim 1, wherein the non-thermal, pulsed microwave plasma (P) stimulates vibrational excitation modes in the carbon dioxide and/or methane components. 3. Dissociation method according to claim 1 or 2, wherein the non-thermal, pulsed microwave plasma (P) is generated by microwave radiation at frequencies between 300 MHz and 40000 MHz. 4. A dissociation process according to any preceding claim, wherein a controlled atmosphere in the reactor chamber (1) varies a pressure in the reactor chamber (1) to modify a plasma temperature depending on the selected dissociation product. 5. Dissociation method according to one of the preceding claims, wherein a microwave energy is continuously applied to the non-thermal, pulsed microwave plasma (P), the continuous microwave energy being lower than the energy of the microwave pulses. 6. Dissociation process according to one of the preceding claims, wherein carbon dioxide is dissociated in the non-thermal, pulsed microwave plasma (P) by dry reforming with methane. 7. A dissociation process according to any preceding claim, wherein volatile components extracted from the reactor chamber (1) are subjected to fractional condensation for sequential extraction of dissociation products. 8. Dissociation method according to one of the preceding claims, wherein a microwave frequency and/or microwave pulse width is selected according to dissociation parameters of the selected dissociation products. 9. Dissociation process according to one of the preceding claims, wherein the carbon dioxide and/or methane component and/or intermediate products are subjected to a catalytic process in the non-thermal, pulsed microwave plasma (P) and/or as part of a post-plasma process. 10. Dissociation method according to one of the preceding claims, wherein gas components which are not dissociated in the non-thermal, pulsed microwave plasma are recycled through the non-thermal, pulsed microwave plasma (P). 11. A dissociation system for dissociating carbon dioxide and/or methane components using a dissociation process including a microwave plasma treatment according to any one of claims 1 to 10, comprising - at least one reactor chamber (1, 1') for receiving the non-thermal, pulsed microwave plasma (P), - at least one microwave generator (2, 2') and plasma applicator for generating the non-thermal, pulsed microwave plasma (P) in the at least one reactor chamber (1, 1'), - at least one inlet (4) for injecting the carbon dioxide and/or methane components into the at least one reactor chamber (1, 1') and exposing the components to the non-thermal, pulsed microwave plasma (P), and - at least one outlet (5) for extracting dissociation products from the reactor chamber (1, 1'). 12. Dissociation system according to claim 11, comprising a control unit for generating the non-thermal, pulsed microwave plasma (P) in the at least one reactor chamber (1, 1') comprising a microwave frequency and/or microwave pulse width modified according to dissociation parameters of the selected dissociation products. 13. Dissociation system according to claim 11 or 12, wherein the non-thermal, pulsed microwave plasma (P) is accommodated in a plasma tube (3) which extends through at least one reactor chamber, wherein preferably the plasma tube (3) subsequently extends through a first reactor chamber (1) and a second reactor chamber (1'). 14. Dissociation system according to one of claims 11 to 13, wherein a pump unit 7 is connected to the at least one reactor chamber (1, 1') or the plasma tube (3) receiving the non-thermal, pulsed microwave plasma (P) for regulating a pressure in the at least one reactor chamber (1, 1') or the plasma tube (3). 15. Dissociation system according to one of claims 11 to 14, wherein the at least one reactor chamber (1, 1') comprises an active impedance matching circuit for the plasma ignition in the at least one reactor chamber (1, 1').