Process and device for obtaining carbon monoxide from atmospheric carbon dioxide, using a solid-plasma reactor

Abstract

The invention relates to a process for producing carbon monoxide from atmospheric carbon dioxide, which can be carried out purely electrically.

Description

[0001] Title: Method and device for obtaining

[0002] Carbon monoxide from atmospheric carbon dioxide using a solid-state plasma reactor

[0003] Description

[0004] The invention relates to a solid-state plasma reactor and its application in the extraction of carbon monoxide from ambient air. The solid-state plasma reactor according to the invention provides a technology that is not limited to the claimed application, but can contribute to solving global challenges of our time. It can contribute to the defossilization of the economy and the closing of material cycles. The term "defossilization" means that the economy increasingly uses fewer fossil fuels and raw materials in production in order to ultimately reduce carbon monoxide emissions. In the context of the invention, the term

[0005] "Gas discharge" is used; it includes both glow discharges and arcs.

[0006] DE 36 31 015 A1 discloses a process for producing a clean gas containing carbon monoxide and hydrogen. This process involves injecting a raw gas into a gasifier by injecting a gaseous oxidizing agent at approximately 1000°C. In the gasifier, wood or coal, for example, is combined with the oxidizing agent to produce a raw gas at a temperature of approximately 440°C. A plasma generator is then used to add further energy to the raw gas in an additional reaction chamber, and the gas is then further purified in several cleaning steps. This process and system are technically complex and require significant amounts of both thermal and electrical energy.

[0007] The invention is therefore based on the object of providing an efficient and economically feasible process for producing carbon monoxide from ambient air, during which no carbon dioxide is released. The extraction of carbon monoxide from ambient air is also referred to as "direct air capture" (DAC) or "carbon capture and utilization" (CCU).

[0008] This object is achieved according to the invention through a two-stage process. In the first stage (the first apparatus), carbon dioxide from the air is dissolved in a caustic absorber with a basic solution of a metal hydroxide or calcium hydroxide (Ca(OH)2). The basic solution reacts with the carbon dioxide from the air via intermediate steps to form metal carbonate or calcium carbonate (CaCO3).

[0009] The metal carbonate or calcium carbonate precipitates from the solution as a powdery solid and can be removed from the absorber at a suitable point.

[0010] The absorption of carbon dioxide from the air is a well-known and established technique. It is carried out using an absorber / air scrubber. This requires a large contact surface between the alkaline solution and the air. Conventional air scrubbers, with or without a packed bed, are ideally suited for this purpose. The air and the alkaline solution can be flowed in cocurrent or countercurrent flow.

[0011] One possibility is the use of a countercurrent air washer with a packed bed, in which the liquid solution flows from top to bottom under gravity, and the air is forced through the air washer from bottom to top by a fan. An alternative is a sprinkler tower, in which the air is moved by updraft or downdraft.

[0012] The moist metal carbonate or calcium carbonate can either be dried in a separate drying process (preferably using waste heat from the reactor according to the invention) or conveyed directly into the solid plasma reactor according to the invention (second apparatus) without prior drying. In the second stage, the metal carbonate or calcium carbonate (CaCO3) is converted into metal oxide or calcium oxide (CaO, cement clinker) in the reactor according to the invention.

[0013] In this process, the carbon dioxide (CO2) absorbed from the atmosphere is released in the reactor. This carbon dioxide is decomposed into carbon monoxide and oxygen in the reactor's plasma, so that after the oxygen is extracted, pure carbon monoxide remains. The solid-state plasma reactor according to the invention is explained in more detail below in connection with Figures 1 to 5.

[0014] The reactions occurring in the process according to the invention are summarized below when the process is carried out on the basis of calcium oxide and calcium carbonate. Alternatively, the process can also be carried out on the basis of metal oxides and metal carbonates.

[0015] Stage 1: Absorption.

[0016] Carbon dioxide (CO2) from the air reacts with the alkaline solution (here NaOH) of the absorption medium. The concentration is, for example, 1 to 7 mol / l

[0017] 2 NaOH + CO2-► Na2CO3+ H20

[0018] This produces sodium carbonate (NaCO3). This reacts further with calcium hydroxide in a causticization process, regenerating sodium hydroxide.

[0019] Ca OH)2+ Na2CO3-> 2 NaOH + CaCO3 The calcium carbonate precipitates as a powder and is removed from the solution.

[0020] The calcium carbonate is dried (optional) and fed into a plasma reactor according to the invention. Due to the high temperatures prevailing in the reactor chamber, the calcium carbonate is burned to calcium oxide:

[0021] CaCO2->CaO + CO2\ H = +181 kJ mol -1

[0022] The calcium oxide present as a solid is removed from the reactor chamber regularly or continuously. This calcium oxide can be dissolved in the aqueous solution of the absorber to close the cycle:

[0023] CaO + H2O -► Ca(OH)2

[0024] The carbon dioxide released during combustion is split in the plasma of the reactor: +283 kJ moC 1

[0025] The resulting oxygen is extracted. Various methods and apparatus known from the state of the art can be used to increase efficiency. The oxygen can be extracted using various processes, e.g., diffusion-driven membranes, electrochemically, by adsorption, or by solid ion conductors. A ceramic membrane, which can selectively conduct oxygen ions at high temperatures, is preferably used for this purpose. This oxygen absorption can—depending on the technology—take place in the reactor chamber of the reactor according to the invention or outside.

[0026] Thus, carbon monoxide is extracted from air in a two-stage process. All other mass flows in the cycle are closed. The overall reaction is

[0027] The energy required for this can be supplied exclusively as electrical energy. If this electrical energy is generated renewably, then the process according to the invention acts as a carbon dioxide sink.

[0028] Air scrubbers (caustic absorbers) are already being used to extract CO2 from air. Their advantage is that they are environmentally friendly and simple; it is a mature and proven technology. The disadvantage is that high temperatures are required to burn the resulting carbonate.

[0029] This problem is solved with the help of the solid-state plasma reactor according to the invention, namely through the use of electrical energy. The energy required to burn the carbonate is provided as non-thermal plasma at very high temperatures in the plasma reactor. In addition, with the help of the plasma, the carbon dioxide produced during the burning of the carbonate is decomposed into carbon monoxide and oxygen. The heat from plasma processes is generated at particularly high temperatures and is therefore particularly suitable for decomposing the carbonate and carbon dioxide. Purely electrical burning of the carbonate is possible, without the use of fossil fuels.

[0030] As an alternative to the calcium carbonate explained in detail, carbonates of other alkali and alkaline earth metals can also be used as absorption media.

[0031] The intermediate step in which sodium carbonate reacts to form calcium carbonate is not absolutely necessary; sodium carbonate could also be burned directly. However, the lower solubility of calcium carbonate facilitates extraction from the solution. In the process described above, NaOH first reacts with CO2 from the air. This makes sense for two reasons:

[0032] . NaOH is very soluble in water .

[0033] The reaction takes place very quickly.

[0034] Only in solution is the carbonate ion transferred from sodium to calcium ion, because this reaction proceeds more slowly than the CO2 bonding. The advantage is that calcium carbonate has very low solubility.

[0035] Alkali metals like sodium or potassium are more soluble and therefore harder to remove from solution. But it is possible.

[0036] Stage 2: Plasma process

[0037] In the plasma reactor according to the invention, no fossil raw materials are required. The thermal energy is provided electrically by the plasma. The resulting carbon dioxide is decomposed directly in the reactor, so that in addition to the metal oxide or calcium oxide, carbon monoxide (CO) is produced as the main product. Carbon monoxide represents a valuable

[0038] Carbon source for the chemical industry.

[0039] When renewable electricity is used to power this process, not only is carbon dioxide (CO2) not released into the environment, but rather carbon dioxide (CO2) is removed from the air. It therefore acts as a carbon dioxide sink.

[0040] Similarly, the process according to the invention can also be carried out using various metal carbonates. The metal oxide is formed along with carbon monoxide and oxygen.

[0041] Oxygen can be extracted from the gas in the same reactor or outside the reactor in the recirculating gas stream. The oxygen can be extracted at high temperatures or after cooling the gas.

[0042] In a particularly preferred variant, the plasma is generated directly in the reactor chamber and not in a separate cavity. This improves heat transfer from the gas to the solid. As a result, the efficiency and conversion rate increase.

[0043] A reactor which can be used to carry out the process comprises a reactor chamber, at least one plasma generator with two electrodes, at least one gas inlet, at least one gas outlet for the product stream and at least one recirculation line, wherein the electrodes of the at least one plasma generator are arranged between the gas inlet and the reactor chamber so that they are flowed through or around by the gas flowing through the gas inlet into the reactor chamber.

[0044] The reactor according to the invention enables a very effective conversion of metal carbonates or calcium carbonate into a metal or calcium oxide and carbon dioxide.

[0045] The following metal carbonates are particularly suitable: lithium, sodium, potassium, magnesium, calcium and zinc

[0046] The energy required for this is supplied to the gas or gas mixture flowing into the reactor chamber by means of a glow discharge or an arc which is present between the electrodes of the plasma generator. The inventive arrangement of the gas inlet and the electrodes of the plasma generator ensures that the gas flowing through the gas inlet into the reactor chamber flows into an intermediate space (hereinafter also referred to as the cavity) between the electrodes of the plasma generator. As a result, the gas comes into contact with a gas discharge taking place between the electrodes. This gas discharge brings at least part of the gas into the plasma-like state.

[0047] At least a portion of the gas leaves the plasma generator as non-thermal plasma with very high temperatures (the electrons have temperatures greater than 10,000 K, the ions have temperatures greater than 1,000 K) and flows directly into the reactor chamber. Due to the very high temperatures of the non-thermal plasma, the reactions and conversion processes in the reactor chamber proceed very reliably and rapidly.

[0048] Immediately after the gas flowing into the reactor chamber through the gas inlet has passed through the reaction zone of the plasma generator (also referred to as plasma), the desired product gas (here, carbon monoxide) is present. A portion of this product gas can be removed via the gas outlet for the product stream.

[0049] The part of the product gas remaining in the reactor chamber flows onto the solid present in the reactor chamber (metal carbonate or calcium carbonate) or flows through it if it is present as a bed. In doing so, it transfers heat to the solid. The heat input decomposes the metal or calcium carbonate and produces a metal or calcium oxide as well as carbon dioxide, which is further decomposed in the reactor into carbon monoxide (product gas) and oxygen.

[0050] The heat is transferred from the very hot non-thermal plasma to the solid in the reactor vessel (by thermal radiation and conduction) at high power and brings the solid reliably and quickly to high temperatures. The part of the product gas drawn off via the gas outlet for the product stream also transfers energy to the solid in the reactor chamber via thermal radiation. Due to the high energy input at high temperatures, a wide variety of carbonates can be reliably broken down into the corresponding oxide and carbon dioxide in the reactor according to the invention. In the application according to the invention, metal carbonate or calcium carbonate (CaCO3) is converted into a metal oxide or calcium oxide (CaO); this requires very high temperatures. At the same time, the carbon dioxide (CO2) released is converted into the desired carbon monoxide.This, among other things, is the basis for the wide range of possible applications of the reactor according to the invention.

[0051] In other words: The electrical energy required to operate the plasma generator is transferred directly to the gas with virtually no loss. If the solid-state plasma reactor according to the invention is powered by renewable electricity, the operation of the reactor does not cause any CO2 emissions.

[0052] A further advantage of the reactor according to the invention is that its power can be controlled very quickly and within a wide range (e.g., between 20% and 100% of the rated power) without negatively impacting the quality of the product gas or the solid products (e.g., quicklime). This makes it possible to purchase this power very cheaply whenever there is a surplus of renewable electricity available in the power grid, thereby improving the economic efficiency of the reactor according to the invention. Furthermore, the shutdown of renewable electricity generation systems (photovoltaics, wind energy converters) can be avoided.

[0053] The thermal energy of the hot gases / plasma in the reactor chamber is, in turn, transferred very efficiently and rapidly to the solids contained therein. Heat transfer occurs not only through conduction but also through thermal radiation. As a result, the solid is decomposed into its components at very high temperatures (greater than 1,000 °C), leaving virtually no residue, or converted into a product (e.g., quicklime), depending on the application.

[0054] Due to the high decomposition temperatures, even problematic compounds in the solids, such as toxins, are decomposed very reliably. Contamination of the solids, for example, with halogens, such as those found in PVC, also poses no problem, since no catalyst is used in the reactor according to the invention, and catalysts are also not required in the subsequent process steps that further process the product gas.

[0055] In a further advantageous embodiment of the invention, the recirculation line connects the reactor chamber to the gas inlet. This means that a portion of the gas flow flowing into the reactor through the gas inlet was previously located in the reactor chamber. The reactions taking place inside the reactor chamber can be controlled by the ratio between the recirculated gas from the reactor chamber and the additional gas supplied to the reactor.

[0056] The proportion of newly added gas relative to recirculated gas can range from 0% to 50%, depending on the application. The recirculated gas can be moved in the recirculation line or in the gas inlet by a blower, a compressor, or a jet pump. To improve the quality of the product gas, the invention provides for the installation of a separator in the recirculation line and / or in the product gas line. This can be used to separate out volatile metals or other disruptive gaseous components, for example. This not only further improves the quality of the product gas but also prevents damage to downstream equipment.

[0057] Furthermore, it is possible, and in many cases advantageous, to provide a heat exchanger in the recirculation line so that part of the thermal energy of the gas in the recirculation line can be transferred to a liquid or gaseous heat transfer medium. This waste heat can be used elsewhere, e.g., in a process upstream or downstream of the reactor according to the invention. This increases the efficiency of the overall process. For example, the waste heat can be used to dry the moist calcium carbonate removed from an air scrubber.

[0058] This is easily possible because the waste heat generated in plasma processes is generated at a high temperature. For example, an absorption system for recovering carbon dioxide from the product gas can be regenerated using the resulting waste heat.

[0059] In some applications of the reactor according to the invention, the demand for high-energy electrons for the decomposition / pyrolysis of the solid in the reactor chamber is so high that waste heat is generated.

[0060] In these cases, the waste heat can be dissipated through the heat exchanger and used elsewhere. It is also possible to install an actuator, such as a slide valve or flow control valve, in the recirculation line, preferably after the heat exchanger, to actively control the gas flow rate through the recirculation line.

[0061] In the gas inlet and / or the recirculation line there is generally arranged a blower or a jet pump which sucks in the gas to be newly introduced into the process as well as the gas flowing through the recirculation line and conveys it into the reactor .

[0062] In order to be able to control the operation of the reactor even better, in addition to or as an alternative to a blower or the jet pump, a controllable flap or a controllable flow valve can be provided in the gas inlet and / or the recirculation line.

[0063] To ensure that the heat transfer and the resulting decomposition or conversion of the starting material, calcium carbonate, into calcium oxide occurs as quickly and efficiently as possible, a preferred embodiment of the invention provides a grate or a rotary tube in the reactor chamber. The solid material lies on the grate or rotary tube and can thus be easily flowed through or against by the hot gas / plasma in the reactor chamber. This intensifies the decomposition and makes it more effective.

[0064] According to the invention it is further provided that the gas outlet for the product flow is arranged between the plasma generator and the grate. The recirculation line in turn is arranged such that the gas flowing through the reactor chamber into the recirculation line first flows past the solid in the reactor chamber and / or at least partially through the solid. This intensifies and accelerates the heat transfer from the hot gas to the solid and consequently accelerates the decomposition of the solid into atoms or short molecules. These are circulated back into the reaction zone of the plasma reactor. The recirculated gas is therefore enriched with intermediate products. In the reaction zone of the plasma generator the intermediate products are converted into the desired product gas, carbon monoxide.

[0065] If the solid is stored on a grate or a rotary tube in the reactor chamber, then it is particularly advantageous if the outlet of the recirculation line and the gas inlet or the plasma generator are arranged on different sides of the grate or the rotary tube, so that the gas has to flow through the solid before it reaches the recirculation line.

[0066] It is particularly preferred if the plasma generator comprises a pin electrode and a concentrically arranged ring electrode. A non-thermal gas discharge occurs between the pin electrode and the ring electrode.

[0067] The geometry of the electrodes and their arrangement ensures that the entire gas mixture flowing through the gas inlet into the reactor chamber is guided through the reaction zone of the plasma reactor. A direct current glow discharge or a non-thermal arc using direct current is preferred. The very high direct voltage required for this can be achieved with the aid of an electrical circuit for providing a direct voltage for the plasma generator. A patent application relating to this was filed by the same applicant on the same day with the EPO (Official File Number PCT / EP2022 / 053608). The disclosure content of this application is hereby incorporated by reference into the content of this patent application.

[0068] However, an alternating voltage can also be applied between the electrodes of the plasma generator.

[0069] Regardless of the type of power supply to the electrodes, a thin, rod-shaped, non-thermal gas discharge is created between the electrodes. In order to optimize the energy transfer from the rod-shaped gas discharge to the gas flowing into the reactor chamber across the entire cross-section of the ring electrode, the invention provides for magnets (electromagnets or permanent magnets) to set the arc or glow discharge in motion so that it moves in a circular motion around the pin electrode. The frequency of this circular motion can be in a range between 50 Hz and several kilohertz. Together with the flow movement of the gas flowing through the ring, this results in very good energy transfer to the gas flowing through the ring electrode. The uniform energy input means that a high conversion of the chemical processes in the plasma can be achieved with each flow.Alternatively, or in addition to this solution using magnets, it is also possible to provide a guide element for the incoming gas upstream of the electrodes. This guide element can, for example, be designed as a honeycomb structure that serves as a flow straightener and flame screen. Alternatively, it is also possible to align the channels of this guide element in such a way that a swirl is imparted to the gas flowing into the reactor chamber. This can also set the gas discharge in motion.

[0070] To ensure that the processes taking place in the reactor chamber can run continuously, a further advantageous embodiment provides for a lock for introducing solids into the reactor chamber. This lock is preferably a gas-tight lock, so that no gas can escape into the environment through the lock during the introduction of solids into the reactor chamber.

[0071] Further advantages and advantageous embodiments of the invention can be found in the following drawings, their description, and the patent claims. All features disclosed in the drawings, their description, and the claims can be essential to the invention both individually and in any combination.

[0072] drawing

[0073] It shows :

[0074] Figure 1 is a simplified and schematic representation of the reactor according to the invention; Figure 2 is a detail concerning the ring electrode and the pin electrode and the conducting element from Figure 1;

[0075] Figures 3, 4 and 5 show different configurations of reactors according to the invention and

[0076] Figure 6 a countercurrent air washer (absorber) for capturing carbon dioxide from the air and

[0077] Figure 7 shows the overall process

[0078] Description of the implementation examples

[0079] Figure 1 shows a highly simplified representation of the plasma reactor 1 according to the invention. It comprises a reactor vessel 3 with a gas inlet 5, a gas outlet 6 for the product stream, and a recirculation line 7.

[0080] Located inside the reactor vessel 3, the reactor chamber 12, is a part of the plasma generator, namely a pin electrode 9 and a ring electrode 11. The pin electrode 9 is generally the cathode in a gas discharge, while the ring electrode 11 is preferably designed as an anode.

[0081] The electrical circuit required to generate the plasma is housed in an external housing which is shown in Figures 3 to 5 .

[0082] The gas inlet 5 is guided in such a way that the inflowing gas flows through a (cylindrical) cavity 17 above the ring electrode 11 and past the central pin electrode 9 to the ring electrode 11. A guide element 21 for the inflowing gas mixture is present in the cavity 17 and can be designed, for example, as an open-pore ceramic foam. It serves as a flow straightener and reduces the heat input from the reactor chamber 12 into the cavity 17 and the gas inlet 5. However, the guide element 21 can also be designed as a honeycomb structure that imparts a swirl to the gas.

[0083] An arc or glow discharge, hereinafter referred to as gas discharge 13, is created between the tip of the pin electrode 9 and the actual ring electrode 11. The inflowing gas is at least partially converted into a non-thermal plasma by the gas discharge, thereby reaching very high temperatures (the electrons have temperatures greater than 10,000 K, the ions have temperatures greater than 1,000 K).

[0084] This plasma then enters the actual reactor chamber 12. There, it transfers the heat by radiation and thermal conduction to the solid 15 located in the lower part of the reactor chamber 12, which is usually in the form of a bed.

[0085] By transporting part of the gas in the reactor chamber via the recirculation line 7 into the gas inlet 5, the residence time of the gas in the reactor chamber 12 and the energy supplied to the gas by the plasma 13 can be controlled.

[0086] Magnets 39 are arranged at the boundary of the cavity 17.

[0087] They can be designed as permanent or electromagnets.

[0088] The resulting magnetic field lines are indicated by dotted lines. Due to the magnetic field lines, the glow discharge 13 makes a circular movement around the pin electrode 9 and thereby sweeps over the entire annular area between the ring electrode 11 and the pin electrode 9. This intensifies the excitation of the gas flowing through the annular area. The plasma created in the reaction zone has, to a first approximation, the shape of a disk due to the rapid rotation of a discharge channel between the pin electrode 9 and the ring electrode 11 at 50 Hz up to several kHz and occupies a large volume.

[0089] Figure 2 shows a detail of the reactor according to the invention in a slightly enlarged manner.

[0090] The guide element 21 can also have a honeycomb structure (not shown), similar to a catalyst. The gas flows from 17 into the reactor chamber 12 through these channels, which run parallel to one another and parallel to the longitudinal axis of the pin electrode 9. This embodiment of a guide element 21 also prevents heat from being introduced into the cavity 17 and acts as a rectifier.

[0091] However, it is also possible to arrange and shape the channels (not shown) of a guide element 21 in such a way that they impart a swirl to the gas. The gas then enters the reactor chamber 3 with a swirl after it has flowed through the guide element 21 and the glow discharge 13. This further improves the distribution of the plasma or of the highly heated gas in the reactor chamber. In some cases, the magnets 39 can be omitted. Figures 3, 4 and 5 show simplified sectional views of differently configured reactors 1 according to the invention. Most of the components in these sectional views are already known. They will therefore not be explained again.

[0092] The electrical circuit of the plasma generator 23, which supplies the electrodes 9, 11 with high voltage (DC or AC) to start and maintain the glow discharge, is schematically represented by a block 41. Details of this circuit can, as already mentioned, be found in a patent application filed by the applicant with the German Patent and Trademark Office (DPMA) on the same day.

[0093] In Figures 3 to 5, the reactor chamber 12 is arranged laterally of the plasma generator 23. Between the plasma generator 23 and the reactor vessel 3, an intermediate piece 43 is provided, to which the gas inlet 5 and the outlet 6 for the product gas are connected.

[0094] In the embodiments according to Figures 3 and 5, a grate 25 is provided in the reactor chamber 12. The solid 15 is located on this grate 25. The embodiments of Figures 3 and 5 differ primarily with regard to the arrangement of the grate 25 relative to the intermediate piece 43. A solid 15 is layered on the grate 15. The recirculation line 7 branches off at the upper end of the reactor vessel 3.

[0095] Figure 4 shows a configuration with an inclined grate. The solid material 15 is located at the bottom of the reactor vessel 3, and the recirculation line 7 is located at the right-hand end of the reactor vessel 3 in Figure 4. The embodiment shown in Figure 5 largely corresponds to the embodiment shown in Figure 3. The positions of the grates 15 differ substantially.

[0096] Figure 6 shows a simplified representation of the two stages or process steps of the method according to the invention, including the associated apparatus.

[0097] A known air scrubber (caustic absorber) 49 is shown. It comprises a wind tower 51 and a circuit for the basic solution (here Na2CO3(aq) + CA(OH)2(aq) => 2 NaOH(aq) + CaCO3.

[0098] In this embodiment, CO2-rich gas (air) flows into the wind tower 51 from above. The aqueous solution, pumped by a circulation pump 55, is sprayed into the wind tower 49 at a bottom 53.

[0099] Droplets of this solution then rain down into a

[0100] On the collecting basin 57, which also serves as a storage container. During the flight phase of the droplets between the floor 53 and the storage container 57, the droplets absorb carbon dioxide from the air.

[0101] Calcium carbonate (CaCo3) separates in the collection basin 57 and is removed either regularly or continuously. This can be done by a centrifuge, a filter, or sedimentation. Calcium oxide and water are added to balance the material balance. (Water is used in large excess to compensate for evaporation.)

[0102] The calcium carbonate (CaCo3) withdrawn from the collecting basin 57 is fed to the plasma reactor 1 according to the invention, which is shown schematically in the lower part of Figure 6.

[0103] The transport of calcium carbonate (CACO3) into reactor 1 and the transport of calcium oxide (CAO) out of reactor 1 can be carried out, for example, by means of a rotary tube (not shown). The calcium carbonate is added at a first end of the rotary tube. The hot gases generated by plasma 13 flow through the rotary tube and convert the calcium carbonate into calcium oxide and carbon dioxide. Calcium oxide arrives at the other end of the rotary tube. This calcium oxide can then be reused in the air scrubber 49.

[0104] In Figure 7, the material flows of the process according to the invention are shown in a kind of block diagram.

[0105] Reference symbol list

[0106] I Plasma reactor

[0107] 3 reactor vessels

[0108] 5 Gas inlet

[0109] 6 Outlet for the product gas

[0110] 7 Recirculation line

[0111] 9 pin electrode

[0112] II Ring electrode 12 Reactor chamber

[0113] 13 Gas discharge

[0114] 15 solids

[0115] 17 Cavity

[0116] 19 - 21 Guide element

[0117] 23 Plasma generator

[0118] 25 Rust

[0119] 27 Lock

[0120] 29 -

[0121] 31 storage containers

[0122] 33 blowers

[0123] 35 first separator

[0124] 37 heat exchangers

[0125] 39 Magnet

[0126] 41 housings

[0127] 43 Intermediate piece

[0128] 49 Air scrubber (caustic absorber)

[0129] 51 Wind Tower

[0130] 53 Floor

[0131] 55 Circulation pump

[0132] 57 On catch basin

Claims

Patent claims 1. Process for the production of carbon monoxide from atmospheric carbon dioxide (CO2) comprising the process steps: - Formation of a metal carbonate (M x (CO3) y ) in an air scrubber (49) from an aqueous solution of a metal hydroxide (M x (0H)2 y ) and carbon dioxide (CO2) from the ambient air, wherein the carbon dioxide (CO2) reacts with the basic or aqueous solution of the metal hydroxide (M x (OH) 2y ) to a metal carbonate (M x (CC>3) y ) reacted, and - Decomposition of the metal carbonate (M) previously formed in the air scrubber (49) x (CC>3) y ) in its oxide (M x 0 y ) and carbon dioxide (CO2) in a solid-state plasma reactor (1) and - Decomposition of carbon dioxide (CO2) into carbon monoxide (CO) and oxygen (O2) also in the solid-state plasma reactor (1) by the plasma (13) .

2. Process for the production of carbon monoxide from atmospheric carbon dioxide (CO2) comprising the process steps: - Formation of sodium carbonate (Na2COs) and water in an air scrubber (49) from an aqueous solution of sodium hydroxide (NaOH) and carbon dioxide (CO2) from the ambient air, wherein the sodium carbonate (Na2COs) reacts with calcium hydroxide (Ca(OH)2) to form calcium carbonate (CaCOs) and sodium hydroxide (NaOH)2, and - Decomposition of the calcium carbonate (CaCOs) previously formed in the air scrubber (49) into calcium oxide (CaO) and carbon dioxide (CO2) in a solid plasma reactor (1) and - Decomposition of carbon dioxide (CO2) into carbon monoxide (CO) and oxygen (O2) also in the solid-state plasma reactor (1) by the plasma (13). A process according to claim 1 or 2, characterized in that the carbon dioxide (CO2) from the air reacts with an aqueous solution via intermediate products. A process according to any of the preceding claims, characterized in that the metal carbonate or the calcium carbonate is removed from the absorption medium and fed into the solid-state plasma reactor (1), and that the metal oxide (M) formed therein x 0 y) or calcium oxide (CaO) is conveyed back into the absorption medium of the air scrubber (49). A method according to any of the preceding claims, characterized in that an oxygen absorber is used in or after the solid-state plasma reactor (1). A method according to any of the preceding claims, characterized in that a partial stream of carbon monoxide (CO) is extracted from the reactor (1) as a product gas. A method according to any of the preceding method claims, characterized in that it is carried out using a reactor (1) according to any of the following apparatus claims. A method according to any of the preceding claims, characterized in that the plasma is generated directly in the reactor chamber (12) of the reactor (1) and not in a separate cavity. The reactor comprises a reactor chamber (12), at least one plasma generator (23) with two electrodes (9, 11), at least one gas inlet (5), a gas outlet (6) for the product stream, and a recirculation line (7), wherein the at least one plasma generator (23) is located between the gas inlet and the gas outlet (6) for the product stream. (5) and the reactor chamber (12) such that it is permeated by the gas or gas mixture flowing into the reactor chamber (12) through the gas inlet (5). . Reactor according to claim 9, characterized in that the recirculation line (7) flows through a separator (35) and / or a heat exchanger (37). . Reactor according to any one of the preceding claims, characterized in that a grate (25) or a rotary tube is provided in the reactor chamber (12). . Reactor according to any one of claims 9 to 11, characterized in that the working gas is directed through the reaction zone of the plasma and then directly onto a solid. . Reactor according to any one of claims 9 to 12, characterized in that the gas outlet (6) for the product flow is arranged between the plasma generator and the grate or solids. Reactor according to one of claims 9 to 13, characterized in that the recirculation line (7) is arranged such that the gas flowing through the reactor chamber (12) into theRecirculation line (7) allows previously flowing gas to pass over and / or through a solid (15) located in the reactor chamber (12). Reactor according to any one of the preceding claims 9 to 14, characterized in that the plasma generator (23) comprises a pin electrode (9) and a ring electrode (11). Reactor according to any one of the preceding claims 9 to 15, characterized in that the plasma generator (23) generates a non-thermal gas discharge (13) by means of a direct current voltage. Reactor according to any one of the preceding claims 9 to 16, characterized in that the plasma generator (23) comprises permanent magnets or a magnetic coil (39) which set an arc or glow discharge (13) present between the pin electrode (9) and the ring electrode (11) in motion.Reactor according to any one of the preceding claims 9 to 17, characterized in that a guiding element (21) for the inflowing gas is provided upstream of the electrodes (9, 11), wherein the guiding element (21) aligns and / or imparts a swirl to the gas flowing through the gas inlet (5) into the plasma generator (23). Reactor according to any one of the preceding claims 9 to 18, characterized in that it comprises a sluice (27) for the continuous or intermittent introduction of solid material (15) into the reactor chamber (12).

Images