CVD si c production reactor for producing si c particles, system and method for producing si c particles

Abstract

The present invention relates to a SiC and chlorosilane production system 2540 comprising at least one CVD SiC production reactor 850, in particular a SiC fluidized bed reactor 850a, in particular a reactor according to claim 9, and a chlorosilane production unit 2550, wherein the chlorosilane production unit 2550 comprises at least a bed reactor 2416, in particular a fixed bed reactor or a fluidized bed reactor, for generating chlorosilane by reacting at least one component of an exhaust gas mixture provided via an exhaust gas outlet 216 of the CVD SiC production reactor 850 with Si, wherein further components of the exhaust gas mixture comprise at least H2 and carbon-containing molecules, in particular methane, and wherein Si is provided as a solid 2398 inside the bed reactor 2416.

Description

Technical Field

[0001] This invention relates to CVD SiC production reactors, systems including such CVD SiC production reactors and chlorosilane production units, and methods for producing silicon carbide (SiC). Background Technology

[0002] Currently, it is not possible to produce high-purity granular SiC. On the one hand, producing granular SiC requires crushing large SiC solids. Because SiC is very hard, crushing or any other mechanical reduction in size causes significant abrasion. This abrasion contaminates the granular SiC.

[0003] Silicon (Si) is known to be produced in fluidized bed reactors (see US4,314,525 and WO2013 / 049314A2). However, Si has significantly lower hardness compared to SiC. Therefore, there is no significant wear during the conventional production of Si. Furthermore, the production of particulate Si does not require carbon (C) molecules.

[0004] CVD SiC production reactors with SiC growth substrates that are resistively heated during SiC production are known from WO2022 / 123083, WO2023 / 222785A1 and WO2022 / 123072A1. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a CVD SiC production reactor that allows for the production of high-purity particulate SiC.

[0006] The aforementioned objective is achieved by the CVD SiC production reactor according to claim 1, particularly a SiC fluidized bed reactor. The CVD SiC production reactor according to the invention preferably comprises at least: a process chamber, wherein the process chamber at least surrounds a reaction zone for growing SiC; and an inlet unit for feeding one or more feed media into the reaction zone of the process chamber for generating or providing a source medium and for generating a fluid flow. The inlet unit is preferably connected to at least one feed medium source, wherein the Si and C feed medium source provides at least Si and C, particularly SiCl3 (CH3), and wherein the carrier gas feed medium source provides a carrier gas, particularly H2; or, wherein the inlet unit is very preferably connected to at least two feed medium sources, wherein the Si feed medium source provides at least Si, and wherein the C feed medium source provides at least C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, and wherein the carrier gas source provides a carrier gas, particularly H2. The CVD SiC production reactor according to the invention further comprises a seed particle supply unit for providing seed particles into the reaction zone. The seed crystal particle preferably has a diameter between 20 µm and 1000 µm. The seed crystal particle supply unit is preferably connected to a feed medium supply conduit or pipe, wherein the seed crystal particle can be conveyed into the feed medium supply conduit or pipe by means of the seed crystal particle supply unit. Therefore, gas flow.

[0007] The reaction zone and the inlet unit are preferably configured to form a fluid flow that holds seed crystal particles, particularly a specified amount of seed crystal particles, within the reaction zone for a specified minimum time of more than 5 seconds, particularly more than 30 seconds, for the purpose of forming SiC particles by SiC accumulation. The CVD SiC production reactor according to the invention further includes a heating unit, particularly an induction heating unit, which is at least partially arranged in the section surrounding the reaction zone and preferably completely surrounds the reaction zone, so as to heat the source medium and seed crystal particles within the reaction zone to a temperature in the range of 1300°C to 2000°C.

[0008] This solution is advantageous because SiC does not need to be crushed or mechanically processed, and therefore there is no wear and tear due to the absence of crushing or mechanical processing, thus eliminating contamination.

[0009] Other preferred embodiments are the subject of the following description and / or dependent claims.

[0010] According to a preferred embodiment of the invention, the reaction zone is at least partially surrounded by one or more insulating sections, wherein the one or more insulating sections are arranged in a tubular manner to form a fluid inflow section for allowing fluid flow into at least a portion of the reaction zone and a fluid outflow section for allowing fluid flow out of the at least a portion of the reaction zone. The term "tubular manner" as used herein describes that the insulating section extends in the direction of fluid flow, particularly in the direction of fluid flow through the reaction zone, or is inclined at an angle of less than 30° or less than 15° relative to the direction of fluid flow, particularly relative to the direction of fluid flow through the reaction zone. Furthermore, the insulating section surrounds the reaction zone circumferentially at least within the section. The cross-sectional shape of the insulating section perpendicular to the fluid flow direction can be rectangular, circular, triangular, or deviate from a rectangular and / or circular and / or triangular shape. According to a preferred embodiment of the invention, the one or more insulating sections comprise or are composed of ceramic materials, particularly oxide ceramic materials (especially TiO2, ZrO2, Al2O3) and / or non-oxide ceramic materials (especially BN, SiC, Si3N5). This embodiment is advantageous because the reaction zone can be heated to temperatures above 1300°C.

[0011] According to another preferred embodiment of the invention, the seed crystal feeding unit is configured to continuously feed seed crystals into the process chamber. Alternatively or additionally, the seed crystal feeding unit may provide seed crystals in a stepwise manner. However, the steps in the stepwise feeding method can also be performed continuously and repeatedly. This embodiment is advantageous because, compared to discontinuous seed crystal feeding, SiC production can be adjusted to an optimal output level and maintained at that optimal level for hours, days, or weeks.

[0012] According to another preferred embodiment of the invention, a gas preheating unit is provided for heating one or more feed media to a temperature above 700°C, particularly above 1100°C or above 1200°C. This gas preheating unit is preferably configured to preheat the one or more feed media before they are fed into the reaction zone via an air inlet unit to generate the fluid flow. Alternatively, the preheating unit or preheating subunit may be provided inside the reactor chamber, particularly at the bottom and / or top of the reactor chamber.

[0013] According to another preferred embodiment of the invention, at least one rotary discharge device, particularly a wing lock or rotary valve, is provided in the section below the reaction zone for removing SiC particles. This rotary discharge device can be operated continuously or incrementally, particularly depending on time and / or weight / force sensor signals.

[0014] According to another preferred embodiment of the invention, an exhaust gas outlet is provided for removing an exhaust gas mixture generated from the process chamber due to the reaction between a fluid flow of one or more feed media and seed crystal particles in the reaction zone. This embodiment is advantageous because a gas flow can be established by means of an intake unit and an exhaust gas outlet.

[0015] The aforementioned objective is also achieved by the SiC and chlorosilane production system according to claim 9. The SiC and chlorosilane production system according to the invention comprises at least one CVD SiC production reactor, particularly a SiC fluidized bed reactor, according to any one of claims 1 to 8, and a chlorosilane production unit. The chlorosilane production unit comprises at least a bed reactor, particularly a fixed bed reactor or a fluidized bed reactor, for generating chlorosilanes by reacting at least one component of an exhaust gas mixture supplied via the exhaust gas outlet of the CVD SiC production reactor with Si, wherein the other component of the exhaust gas mixture comprises at least H2 and carbon-containing molecules, particularly methane, and wherein Si is provided as a solid within the bed reactor. This embodiment is advantageous because the gas flow passes through the reaction zone at a high speed. The gas flow velocity is preferably variable, particularly by means of the inlet unit. The gas flow velocity is preferably greater than 0.5 m / s or greater than 1 m / s, and preferably greater than 5 m / s, and very preferably greater than 10 m / s. The gas flow velocity is preferably between 0.1 m / s and 100 m / s, particularly between 1 m / s and 90 m / s, and more preferably between 1 m / s and 70 m / s, wherein the gas flow velocity can be increased over time, especially to compensate for the mass accumulation of the grown particles. Therefore, only a small amount of C and Si from one or more feed media can be transferred to the seed particles or grown particles in the reaction zone. Since the gas flow is altered by the reaction in the reaction zone, for example, the presence of HCl, the gas flow after the reaction zone, or the exhaust gas, still has value but is contaminated. Continuously supplying newly purchased feed media would be very costly and therefore would not allow for large-scale production of SiC particles.

[0016] According to another preferred embodiment of the invention, the chlorosilane production unit includes a separation unit, particularly a distillation column, for separating one or more metals (particularly B, Al, Fe and / or P) from the chlorosilanes (particularly STC and / or TCS) generated by the bed reactor. This embodiment is advantageous because Si can be provided inside the bed reactor containing the metal component or inside the reactor chamber.

[0017] According to another preferred embodiment of the invention, the chlorosilane production unit includes a fluid outlet connected to the inlet unit of a CVD SiC production reactor via a pipe or hose for conducting the generated chlorosilane, thereby feeding the generated chlorosilane into the process chamber of the CVD SiC production reactor, and / or connected to the inlet unit of another CVD SiC production reactor, thereby feeding the generated chlorosilane into the process chamber of that other CVD SiC production reactor. This embodiment is advantageous because new chlorosilane can be produced using exhaust gas, and can be transferred back to the CVD SiC production reactor and / or used in another CVD SiC production reactor after production.

[0018] The above objective is also achieved by the method for producing silicon carbide (SiC) according to claim 12. The method for producing silicon carbide (SiC) according to the invention comprises at least the following steps: providing a CVD SiC production reactor, particularly a CVD SiC production reactor according to any one of claims 1 to 8, wherein the CVD SiC production reactor includes a process chamber, wherein the process chamber at least surrounds a reaction zone for growing SiC; feeding one or more feed media into the reaction zone of the process chamber via an inlet unit for generating or providing a source medium and for generating a fluid flow, wherein the inlet unit is preferably connected to at least one feed media source. The Si and C feed media source is very preferably providing at least Si and C, particularly SiCl3 (CH3), and wherein the carrier gas feed media source is preferably providing a carrier gas, particularly H2. Alternatively, the inlet unit is preferably connected to at least two feed media sources. The Si feed medium source preferably provides at least Si, and the C feed medium source preferably provides at least C (especially natural gas, methane, ethane, propane, butane, and / or acetylene), and the carrier gas medium source preferably provides a carrier gas, especially H2. The method preferably further includes the following steps: providing seed crystal particles into the reaction zone, particularly by means of a seed crystal particle supply unit, wherein the seed crystal particles preferably have a diameter between 20 µm and 1000 µm; and forming a fluid flow in such a way that the seed crystal particles, particularly a specified amount of seed crystal particles, are held within the reaction zone for a specified minimum time of more than 5 seconds, particularly more than 30 seconds, for the purpose of forming SiC particles by accumulating SiC; and heating the source medium and seed crystal particles within the reaction zone to a temperature in the range of 1100°C to 2200°C, particularly in the range of 1300°C to 2000°C.

[0019] According to a preferred embodiment of the invention, seed crystals are continuously supplied to the process chamber by means of a seed crystal supply unit. This embodiment is advantageous because the production of SiC particles can be set to an optimal level, particularly an optimal efficiency level or an optimal growth level.

[0020] According to a preferred embodiment of the invention, before one or more feed media are fed into the reaction zone by means of an inlet unit to generate a fluid flow, the feed media are preheated to a temperature above 700°C, particularly above 1100°C, by means of a gas preheating unit. The gas preheating unit preferably includes a heat exchanger device for transferring heat from the exhaust gas to the feed media and / or the carrier gas, particularly H2, provided by a carrier gas feed medium source. This embodiment is advantageous because the gas can flow through the reaction zone at high speed without cooling the reaction zone by means of cold gas. Furthermore, due to the heat exchanger device, the energy of the exhaust gas can be reused to heat the feed media and / or the carrier gas.

[0021] According to a preferred embodiment of the invention, SiC particles are removed from the process chamber by means of at least one rotary unloading device, particularly a wing lock or rotary valve. This embodiment is advantageous because it allows the rotary unloading device to be operated continuously or gradually, particularly depending on time and / or weight / force sensor signals. Therefore, SiC particles can be removed from the process chamber continuously or gradually.

[0022] In the context of this invention, the SiC particles preferably define a plurality of SiC objects, wherein the maximum extension of each SiC object between two surface points is between 2 mm and 20 cm or between 5 mm and 10 cm, and preferably between 5 mm and 19 cm, and very preferably between 5 mm and 17 cm, and most preferably between 5 mm and 15 cm or 10 cm.

[0023] According to a preferred embodiment of the invention, the seed crystal particles are made of or comprise at least 90% by mass of C, particularly at least 98% by mass of C, and preferably at least 99% by mass of C, and very preferably at least 99.9% by mass of C, and most preferably at least 99.99% by mass of C. This embodiment is highly advantageous because C has a much lower mechanical strength compared to SiC. Therefore, the production of seed crystal particles containing C results in much less wear and consequently much less contamination.

[0024] According to a preferred embodiment of the invention, the seed crystal particles are made of SiC or comprise at least 90% by mass of SiC, particularly at least 98% by mass of SiC, and preferably at least 99% by mass of SiC, and very preferably at least 99.9% by mass of SiC, and most preferably at least 99.99% by mass of SiC. This embodiment is advantageous because the SiC seed crystal particles directly accumulate SiC.

[0025] Alternatively or concurrently, some seed crystals may contain SiC, and some seed crystals may contain C and / or Si.

[0026] According to a preferred embodiment of the invention, the step of removing the exhaust gas mixture generated from the process chamber due to the reaction between a fluid flow of one or more feed media and seed crystal particles in the reaction zone is performed via an exhaust gas outlet. This embodiment is advantageous because it allows for a high gas flow rate through the reaction zone.

[0027] According to a preferred embodiment of the invention, at least a first component of the exhaust gas mixture is HCl, wherein a second component of the exhaust gas mixture is preferably composed of exhaust gas chlorosilanes, particularly STC and / or TCS, wherein a third component of the exhaust gas mixture preferably includes or is composed of H2, and wherein a fourth component of the exhaust gas mixture preferably includes or is composed of at least one carbon-containing molecule, particularly methane, or is composed of at least one carbon-containing molecule, particularly methane.

[0028] According to another preferred embodiment of the invention, the following steps are performed: providing solid Si inside the reactor chamber of the chlorosilane production unit, wherein the solid Si includes metallic impurities greater than 1000 ppmw; conveying at least a second component of the exhaust gas mixture, and preferably a second component and a third component of the exhaust gas mixture, and one or more components of the exhaust gas mixture, and particularly preferably at least a second component and a first component of the exhaust gas mixture, and most preferably all components of the exhaust gas mixture, into the reactor chamber; and generating chlorosilane inside the reactor chamber by reacting the second component of the exhaust gas mixture, particularly STC and / or TCS, with solid Si, and preferably by reacting at least the second component and the first component of the exhaust gas mixture.

[0029] This solution is advantageous because it allows the use of exhaust gas components to generate chlorosilanes. Therefore, total output can be increased, and less feed gas needs to be transported from the feed gas production unit. Consequently, less transportation leads to less resource consumption, and the risk of accidents and therefore pollution is reduced.

[0030] In view of this disclosure, the term "reaction" must be understood in conjunction with the chemical vapor deposition step.

[0031] According to another preferred embodiment of the invention, the step of removing the generated chlorosilanes from the chlorosilane production unit is performed. This embodiment is advantageous because the removed chlorosilanes can be stored or transferred to the CVD SiC production reactor.

[0032] According to another preferred embodiment of the invention, the following steps are preferably performed: transferring at least the generated chlorosilane removed from the chlorosilane production unit to a process chamber of a CVD SiC production reactor, and transferring at least one carbon-containing molecule into the CVD SiC production reactor, thereby producing SiC within the process chamber of the CVD SiC production reactor by reacting the generated chlorosilane with C from the at least one carbon-containing molecule on at least one deposition surface. Alternatively, the following steps may be performed: transferring at least the generated chlorosilane removed from the chlorosilane production unit to a process chamber of another CVD SiC production reactor, and transferring at least one carbon-containing molecule into the other CVD SiC production reactor, thereby producing SiC within the process chamber of the other CVD SiC production reactor by reacting the generated chlorosilane with C from the at least one carbon-containing molecule on at least one deposition surface.

[0033] This solution is advantageous because it allows the use of exhaust gas components to generate chlorosilanes. Therefore, total output can be increased, and less feed gas needs to be transported from the feed gas production unit. Consequently, less transportation leads to less resource consumption, and the risk of accidents and therefore pollution is reduced.

[0034] In view of this disclosure, the term "reaction" must be understood in conjunction with the chemical vapor deposition step.

[0035] According to another preferred embodiment of the invention, the step of reducing the amount of metal impurities in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw, and most preferably below 1 ppmw is performed. This embodiment is advantageous because SiC free of such metal impurities can be used to produce a wide range of products, particularly in chips and power devices.

[0036] According to another preferred embodiment of the invention, before the generated chlorosilane is transferred to the process chamber of the CVD SiC production reactor or another CVD SiC production reactor, or before the generated chlorosilane is removed from the chlorosilane production unit, a step is performed to reduce the amount of metallic impurities in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw, and most preferably below 1 ppmw. This embodiment is advantageous because it prevents contamination of the CVD SiC production reactor. Therefore, less downtime is required for cleaning or maintenance.

[0037] According to another preferred embodiment of the invention, the step of reducing the amount of metallic impurities (at least Fe impurities, Al impurities, and / or all metallic impurities) in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw, and most preferably below 1 ppmw, is divided into at least a first removal step and a second removal step, wherein a first amount of metallic impurities is removed in the first removal step, and a second amount of metallic impurities is removed in the second removal step. This embodiment is advantageous because different conditions and / or techniques can be applied to remove metallic impurities depending on the specific metallic impurity; therefore, by removing metallic impurities in multiple steps, particularly two or more steps, the efficiency of each step can be improved.

[0038] The third component of the generated chlorosilane and exhaust gas mixture, as well as the fourth component of the exhaust gas mixture, are separated into a first fluid and a second fluid.

[0039] According to another preferred embodiment of the invention, the steps of reducing the amount of metallic impurities (at least Fe impurities, Al impurities and / or all metallic impurities) in the generated chlorosilane to less than 20 ppmw, and preferably less than 10 ppmw, and very preferably less than 5 ppmw, and most preferably less than 1 ppmw, as well as the steps of separating the third component of the mixture of the generated chlorosilane and the exhaust gas and the fourth component of the exhaust gas mixture into a first fluid and a second fluid, are performed by a separation unit.

[0040] The first removal step, as well as the step of separating the third component of the generated chlorosilane and exhaust gas mixture and the fourth component of the exhaust gas mixture into the first fluid and the second fluid, are performed by the separation unit.

[0041] According to another preferred embodiment of the invention, the second removal step is performed by another apparatus, particularly another separation unit, especially a chlorosilane distillation column.

[0042] According to another preferred embodiment of the invention, after the step of separating the third component of the generated chlorosilane and the exhaust gas mixture and the fourth component of the exhaust gas mixture into a first fluid and a second fluid, a step of reducing the amount of metal impurities in the generated chlorosilane to less than 20 ppmw, and preferably less than 10 ppmw, and very preferably less than 5 ppmw is performed.

[0043] According to another preferred embodiment of the invention, the exhaust gas mixture is fed from a CVD SiC production reactor into a reactor chamber, wherein the reactor chamber is part of a bed reactor, and / or the exhaust gas mixture is fed from at least one additional CVD SiC production reactor into the reactor chamber, wherein the reactor chamber is part of a bed reactor, wherein the step of generating chlorosilanes by reacting a first component of the exhaust gas mixture with Si is performed inside the bed reactor, and / or the step of generating chlorosilanes by reacting a second component of the exhaust gas mixture, particularly STC, and a third component of the exhaust gas mixture with solid Si is performed inside the bed reactor, wherein the bed reactor is preferably a fixed-bed reactor or a fluidized-bed reactor. This embodiment is advantageous because multiple components of the exhaust gas can be used to generate chlorosilanes, particularly simultaneously. Therefore, less HCl treatment and a reduced supply of fresh chlorosilanes are possible, making the method according to the invention highly efficient.

[0044] Preferably, the exhaust gas mixture is fed into the bed reactor without chemical treatment. Chemical treatment, as used herein, is understood to be any treatment that removes a component or substance from the exhaust gas mixture, particularly by distillation.

[0045] However, it is also possible to remove HCl, STC, or TCS from the exhaust gas mixture before the step of generating a chlorosilane by reacting at least one component of the exhaust gas mixture with Si. Preferably, HCl can be removed. In this case, the at least one component of the exhaust gas mixture reacting with Si is preferably STC. Alternatively, STC can be removed from the exhaust gas mixture before the step of generating a chlorosilane by reacting at least one component of the exhaust gas mixture with Si. In this case, the at least one component of the exhaust gas mixture reacting with Si is preferably STC.

[0046] According to another preferred embodiment of the invention, the exhaust gas mixture is removed from the CVD SiC production reactor or at least one other CVD SiC production reactor in a heated configuration, wherein the exhaust gas mixture has a condensation temperature and is maintained above the condensation temperature.

[0047] According to another preferred embodiment of the invention, during the step of generating chlorosilanes by reacting HCl with Si, solid Si is fed into a bed reactor. This embodiment is advantageous because the bed reactor can be operated continuously and therefore can be coupled to multiple CVD SiC production reactors for generating chlorosilanes based on the exhaust gases from said multiple CVD SiC production reactors.

[0048] According to another preferred embodiment of the invention, during the step of generating chlorosilanes by reacting HCl with Si, solid Si is fed into a bed reactor. This embodiment is advantageous because the bed reactor can be operated continuously.

[0049] According to another preferred embodiment of the invention, at least one carbon-containing molecule is a component of the second fluid, or the second fluid is composed of the at least one carbon-containing molecule, wherein the step of conveying the at least one carbon-containing molecule into the process chamber includes conveying the second fluid into the process chamber. The second fluid preferably comprises methane. Additionally, the step of conveying the at least one carbon-containing molecule into the process chamber may also include conveying a carbon-containing molecule (particularly the same carbon-containing molecule, especially methane) from another carbon-containing molecule source (particularly from another methane source). This embodiment is advantageous because carbon-containing molecules from the exhaust gas can be used to produce SiC. However, additional carbon-containing molecules can be provided if they are not available in sufficient mass or volume.

[0050] According to another preferred embodiment of the invention, a step of removing HCl from the second fluid is performed prior to the step of conveying at least one carbon-containing molecule into the process chamber. This embodiment is advantageous because the removed HCl can be used to produce chlorosilanes, and thus improves the efficiency of the invention.

[0051] According to another preferred embodiment of the invention, prior to the step of conveying the chlorosilane into the process chamber, a step is performed to convey the first fluid from the separation unit to another separation unit to separate the first fluid into at least a first portion and a second portion. This embodiment is advantageous because unwanted portions can be removed from the first fluid. Therefore, according to another preferred embodiment of the invention, the additional separation unit preferably performs a step of reducing the amount of metal impurities in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw, wherein the first portion of the two portions comprises chlorosilane, and wherein the second portion of the two portions includes the metal impurities removed during the step of reducing the amount of metal impurities in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw.

[0052] According to another preferred embodiment of the invention, prior to the step of conveying the chlorosilane into the process chamber, a step is performed to convey the first fluid from the separation unit to another separation unit to separate the first fluid into at least a first portion and a second portion. The first portion of the two portions is preferably or preferably includes TCS (trichlorosilane), and the second portion of the two portions is preferably or preferably includes STC (silicon tetrachloride).

[0053] According to another preferred embodiment of the invention, the step of conveying chlorosilane into the process chamber includes conveying a first portion of the two portions and / or a second portion of the two portions into the process chamber, or the step of conveying chlorosilane into the process chamber is constituted by conveying a first portion of the two portions and / or a second portion of the two portions into the process chamber. This embodiment is advantageous because the chlorosilane provided by the exhaust gas and the chlorosilane generated or produced inside the reactor chamber can be used to produce SiC.

[0054] According to another preferred embodiment of the invention, a first reservoir and / or conductive element connects a separation unit to a further separation unit, wherein the further separation unit is connected to an STC reservoir and a TCS reservoir, wherein the STC reservoir and / or TCS reservoir form segments of a chlorosilane mass flux path for conducting STC and / or TCS to the process chamber. This embodiment is advantageous because the supply of chlorosilane removed from the exhaust gas and produced by reacting one or more components of the exhaust gas with Si to the process chamber is independent of the actual output of the reactor chamber, as the necessary mass or volume of chlorosilane can be transferred from the respective reservoirs, i.e., the STC reservoir and / or TCS reservoir.

[0055] According to another preferred embodiment of the invention, the additional separation unit is a distillation column. This embodiment is advantageous because the distillation column is very reliable and capable of handling high throughput.

[0056] According to another preferred embodiment of the invention, STC is fed from another separation unit, particularly a distillation column, into an STC storage tank, and TCS is fed from another separation unit, particularly a distillation column, into a TCS storage tank.

[0057] According to another preferred embodiment of the invention, the metal chloride (e.g., FeCl3 or AlCl3) leaves the reactor chamber, particularly the reactor chamber of a bed reactor, either in particulate form or in the gas phase, depending on the conditions. The particulate solid metal chloride can be discharged, for example, via solid separation (cyclone separator, filter). Reference is made here to document DE2161641A1, as document DE2161641A1 discloses, for example, separation devices or other separation devices, particularly distillation columns.

[0058] According to another preferred embodiment of the invention, the gaseous metal chloride is carried to a condenser and forms a solution and / or suspension that can be separated by distillation. The resulting metal-rich reboiling component is preferably discharged.

[0059] According to another preferred embodiment of the invention, STC is fed from the STC reservoir into the CVD SiC production reactor, instead of TCS being fed from the TCS reservoir into the bed reactor. This embodiment is advantageous because the components of STC, which are part of the exhaust gas, can react to form TCS inside the bed reactor.

[0060] According to another preferred embodiment of the invention, a buffer reservoir is arranged or provided in the direction of fluid flow before the reactor chamber, particularly the reactor chamber of a bed reactor. This embodiment is advantageous because the buffer reservoir can store the exhaust gas output from the SiC CVD reactor for continuous supply to the reactor chamber. The exhaust gas inside the buffer reservoir is preferably heated or maintained above the condensation temperature of the exhaust gas or above the lowest condensation temperature of the individual components of the exhaust gas.

[0061] According to another preferred embodiment of the invention, the distillation column separates one or more metallic components (particularly B, Al, Fe and / or P) from a first fluid, particularly classifying them before separating STC and TCS, wherein the separated metallic components are preferably fed into a waste storage tank. This embodiment is advantageous because Si can be supplied inside the bed reactor containing the metallic components or inside the reactor chamber.

[0062] According to another preferred embodiment of the invention, TCS is fed from a TCS reservoir into a bed reactor for the conversion of at least one component of TCS into STC, or STC is fed from an STC reservoir into a bed reactor for the conversion of at least one component of STC into TCS. This embodiment is advantageous because multiple reactions can be performed within the bed reactor, particularly simultaneously.

[0063] According to another preferred embodiment of the invention, the step of generating chlorosilanes is performed inside the reactor chamber by reacting a first component of the exhaust gas mixture with solid Si. This embodiment is advantageous because multiple components of the exhaust gas are used to react with Si to produce chlorosilanes. Therefore, the overall efficiency of this solution is very high.

[0064] The aforementioned objective is also achieved by the SiC and chlorosilane production system according to claim 27. The SiC and chlorosilane production system according to the invention comprises at least: a chlorosilane production unit, wherein the chlorosilane production unit includes at least a bed reactor, particularly a fixed-bed reactor or a fluidized-bed reactor, for generating chlorosilanes by reacting at least one component of an exhaust gas mixture supplied via the exhaust gas outlet of a CVD SiC production reactor with Si, wherein the other components of the exhaust gas mixture include at least H2 and carbon-containing molecules (particularly methane), and wherein Si is provided as a solid inside the bed reactor; and a CVD SiC production reactor, particularly a SiC fluidized-bed reactor, according to any one of claims 1 to 8, for producing SiC, wherein the chlorosilane production unit and the CVD SiC production reactor are connected at least via conduits, particularly pipes, for feeding the chlorosilanes generated by means of the chlorosilane production unit into the CVD SiC production reactor for SiC production. The exhaust gas may be provided by the same CVD SiC production reactor that receives the generated chlorosilanes. However, the exhaust gas may also be provided by another CVD SiC production reactor. The other CVD SiC production reactor may be a different type or the same type of CVD SiC production reactor as the one receiving the generated chlorosilanes. This other CVD SiC production reactor may include one or more resistance-heated growth substrates. Attached Figure Description

[0065] The invention is explained with reference to the accompanying drawings, in which:

[0066] Figure 1a An example of a CVD SiC production reactor according to the present invention is shown schematically.

[0067] Figure 1b The diagram schematically illustrates the feeding of seed crystal particles into the reaction zone and the growth of SiC particles within the reaction zone.

[0068] Figure 1c The definition of the term "maximum extension between two surface points" is illustrated schematically.

[0069] Figures 2 to 9 Different examples of SiC and chlorosilane production systems according to the present invention are illustrated schematically. Detailed Implementation

[0070] Figure 1 illustrates an example of a CVD SiC production reactor 850 according to the present invention, particularly a SiC fluidized bed reactor 850a. The CVD SiC production reactor 850a includes a process chamber 856, which at least surrounds a reaction zone 2500 for SiC growth. In the lower region of the process chamber 856, particularly below the reaction zone 2500, an inlet unit 866 is provided. The inlet unit 866 is for feeding one or more feed media into the reaction zone of the process chamber 856 to generate or provide a source medium and to generate a fluid flow, wherein the inlet unit 866 is connected to at least one feed medium source 851, wherein the Si and C feed medium source 851 provides at least Si and C, particularly SiCl3 (CH3), and wherein the carrier gas feed medium source 853 provides a carrier gas, particularly H2. Alternatively, the intake unit 866 is connected to at least two feed medium sources 851, 852, wherein the Si feed medium source 851 provides at least Si, the C feed medium source 852 provides at least C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, and the carrier gas source 853 provides a carrier gas, particularly H2. Reference numeral 2506 refers to a seed crystal particle supply unit 2506 for supplying seed crystal particles 2508 to the reaction zone 2500, wherein the seed crystal particles have a diameter between 20 µm and 1000 µm. The seed crystal particle supply unit 2506 is preferably connected to the intake unit 866 to feed the seed crystal particles as part of the gas flow into the process chamber 856, particularly into the reaction zone 2500. However, alternatively, the seed crystal feeding unit 2506 can be positioned above the reaction zone 2500, allowing the seed crystal to fall into the reaction zone from above. The reaction zone 2500 is preferably understood as the volume within the process chamber 856, within which the conditions for chemical vapor deposition can be set during operation of the CVD SiC production reactor 850. The boundaries of the reaction zone 2500 are schematically shown by reference numerals 2501 and 2502, where 2501 indicates the upper boundary of the reaction zone 2500, and 2502 indicates the lower boundary of the reaction zone 2500. The sidewalls of the reaction zone 2500 are preferably covered with, made of, or comprised of an insulating material. Therefore, the reaction zone 2500 is at least partially surrounded by one or more insulating sections 2516, wherein the one or more insulating sections 2516 are arranged in a tubular manner to form a fluid inflow section 2502 for allowing fluid to flow into at least a portion of the reaction zone 2500 and a fluid outflow section 2501 for allowing fluid to flow out of the at least a portion of the reaction zone 2500.

[0071] The seed crystal feeding unit 2506 is preferably configured to continuously feed seed crystal particles 2508 into the process chamber 856. In the example shown, the seed crystal feeding unit 2506 is connected to a conduit or pipe 2522 for feeding a feed medium into the process chamber 856. An actuator, particularly an electric motor 2507, is used to continuously or gradually convey the seed crystal particles 2508.

[0072] Figure 1b The reaction zone 2500 and the inlet unit 866 are preferably configured to form a fluid flow such that a seed crystal particle 2508, particularly a specified amount or mass of seed crystal particles 2508 or grown SiC particles 2510, is held within the reaction zone 2500 for a specified minimum time of more than 5 seconds, particularly more than 30 seconds, by means of a fluid flow 2509, for the purpose of forming SiC particles 2512 by accumulating SiC. Reference numeral 2510 refers to a SiC particle or bulk material containing more mass than a seed crystal particle but less mass than the ultimately grown SiC particles 2512 or bulk material. The ultimately grown SiC particles 2512 preferably move in the opposite direction 2514 of the gas flow 2509, particularly exiting the reaction zone 2500 via the lower boundary 2502 of the reaction zone 2500.

[0073] also, Figure 1a and Figure 1b At least one rotary unloading device 2518 is shown, which is disposed in a section below the reaction zone 2500 for removing SiC particles 2512 from the process chamber 856.

[0074] Figure 1a and Figure 1b Heating unit 2504, particularly induction heating unit 2504, is shown. Heating unit 2504 is arranged at least in a segment surrounding reaction zone 2500 for heating the source medium and seed crystal particles 2508 inside reaction zone 2500 to a temperature in the range of 1300°C to 2000°C.

[0075] An exhaust gas outlet 216 is provided for removing an exhaust gas mixture generated from the process chamber 856 due to the reaction between a fluid flow of one or more feed media and seed crystal particles 2508 or grown SiC particles 2510 in the reaction zone 2500. This exhaust gas outlet is preferably located above the reaction zone 2500, and more preferably within the top wall section 2524 of the process chamber 856.

[0076] Reference numeral 854 designates a preferred, optional mixing device or mixer by means of which the source fluid and / or carrier fluid can be mixed together, particularly in a predetermined ratio. Reference numeral 855 designates a gas preheating unit, which may be or may include an evaporator device or evaporator by means of which the fluid mixture supplied from the mixing device 854 to the evaporator device 855 can be evaporated. The gas preheating unit 855 may be formed of or may include a heat exchanger for transferring heat from the exhaust gas of the SiC production apparatus 850a to the fluid mixture supplied by the mixing device 854. The gas preheating unit 855 is preferably configured to heat one or more feed media to a temperature above 700°C, particularly above 1100°C. The gas preheating unit 855 is preferably configured to preheat the feed medium or feed media before feeding one or more feed media into the reaction zone 2500 by means of the air inlet unit 866 to generate a fluid flow.

[0077] An apparatus 850a for producing SiC materials, particularly 3C-SiC materials, especially 3C-SiC particulate materials. The apparatus 850 preferably includes a first feed device 851, a second feed device 852, and a third feed device 853. The first feed device 851 is preferably designed as a first mass flow controller, particularly for controlling the mass flow rate of a first source fluid, particularly a first source liquid or a first source gas, wherein the first source fluid preferably includes Si, particularly silanes / chlorosilanes of the general formula SiH4-mClm or organochlorosilanes of the general formula SiR4-mClm (where R = hydrogen, hydrocarbon, or chlorinated hydrocarbon). The second feed device 852 is preferably designed as a second mass flow controller, particularly for controlling the mass flow rate of a second source fluid, particularly a second source liquid or a second source gas, wherein the second source fluid preferably includes C, such as hydrocarbons or chlorinated hydrocarbons, preferably with a boiling point <100°C, and particularly preferably methane. The third feed device 853 is preferably designed as a third mass flow controller, particularly for controlling the mass flow rate of the carrier fluid, especially the carrier gas, wherein the carrier fluid or carrier gas preferably comprises H or H2, or a mixture of hydrogen and an inert gas.

[0078] Figure 1c This illustration schematically shows an example of how the "maximum extension between two surface points" of SiC particles 2512 or SiC bulk 2512 is used in the context of this invention. The maximum extension between two surface points is indicated by reference numeral 2520.

[0079] Figure 2An example of a system according to the invention is shown. The system includes at least one CVD SiC reactor 850a (designated 850a and 850b in the case of multiple CVD SiC reactors) and at least one reactor, particularly a bed reactor 2416, for reacting Si with one or more components of the exhaust gas from the CVD SiC reactor 850a to produce chlorosilanes, particularly STC and / or TCS. The chlorosilanes produced inside reactor 2416 can be transferred to the CVD SiC reactor 850a, which provides the exhaust gas for chlorosilane production. Alternatively or additionally, the generated chlorosilanes can be transferred to another CVD SiC reactor 850a / 850b, i.e., a CVD SiC reactor of the same type (bed reactor) or another type (with a resistance-heated growth substrate).

[0080] According to the present invention, the CVD SiC reactor 850b preferably includes at least one process chamber 856a / b and at least one, preferably multiple, SiC growth substrates 857a / b arranged or potentially arranged within the CVD SiC reactor 850a / b. The CVD SiC reactor 850a / b preferably includes at least one or exactly one exhaust gas outlet 216, wherein the exhaust gas outlet 216 is preferably directly or indirectly connected to the gas inlet 2417 of the reactor 2416 via an exhaust gas conduit 2400. The reactor 2416 includes a reactor chamber 2419, within which solid Si 2398 is provided. The solid Si 2398 is preferably provided in granular form.

[0081] The solid Si 2398 particles preferably have a length between 1 mm and 50 mm, more preferably between 1 mm and 40 mm, very preferably between 1 mm and 15 mm, and most preferably between 1 mm and 5 mm or 10 mm. The solid Si 2398 is preferably crushed by means of a crushing device (not shown). The crushing device may be part of the system. The crushing device is preferably a jaw crusher or a water pulse crusher. The crushing device preferably provides Si particles continuously. This also applies to the following figures.

[0082] about Figure 2 As with the remaining figures, it must be noted that fluid outlet 216 and fluid inlet 2417 are shown only schematically, and other fluid inlets and / or outlets need not be explicitly mentioned and / or shown.

[0083] Reactor 2416 preferably outputs at least chlorosilane 2394. The arrows indicate that chlorosilane 2394 can be fed into CVDSiC reactors 850a and / or 850b.

[0084] Furthermore, the dashed arrows indicate that additional substances can be optionally fed into CVD SiC reactor 850a (and similarly, into CVD SiC reactor 850b). These additional substances can be, for example, carbon-containing molecules (particularly CH4 (methane)) and / or H2 (hydrogen). This additional substance can also be fed through the same inlet into CVD SiC reactor 850 via chlorosilane.

[0085] According to another preferred embodiment of the invention, an exchange device 2460 is optionally provided for exchanging 3-15% by volume of a second fluid 626. The second fluid 626 preferably comprises H2, methane, HCl, and chlorosilane, wherein the composition ratio ((H2:methane:HCl:chlorosilane)) in the second liquid is preferably between 3:1:0.1:0.1 (volume ratio) and 7:1:0.1:0.1 (volume ratio). Alternatively, an absorber device (see [link to absorber device]) can be provided. Figure 9 (Ref. 2436) is used to remove additional impurities, such as phosphorus, dust, and / or metals. Both the exchange device 2460 and the absorber device 2436 are optional, but may also be part of the following figures. Regarding the exchange device 2460, its function can also be achieved by removing 3-15% by volume of the second fluid 626 and adding the same amount of removed material via one or more other input devices, particularly input path 2462. Therefore, the exchange device 2460 may simply be a removal device for removing 3-15% by volume of the second fluid 626. This also applies to the following figures.

[0086] Figure 3 Further detailed examples of the system according to the invention are shown. According to Figure 3 A separation unit 602 is provided downstream of reactor 2416. This separation unit 602 is preferably configured to separate a third component 2401 of the generated chlorosilane 2394 and exhaust gas mixture 2400, and a fourth component of the exhaust gas mixture 2400, into a first fluid 624 and a second fluid 626. The first fluid 624 is preferably fed into a storage unit, particularly a first fluid storage unit 2412, or into CVD SiC reactor 850a and / or another CVD SiC reactor 850b. The second fluid 626 is preferably fed into another storage unit, particularly a second fluid storage unit 2414, or into CVD SiC reactor 850a and / or another CVD SiC reactor 850b.

[0087] Furthermore, according to another preferred embodiment, the separation unit 602 may be configured to reduce the amount of metallic impurities in the generated chlorosilane to below 20 ppmw, and preferably below 10 ppmw, and very preferably below 5 ppmw, and most preferably below 1 ppmw. The removed metallic impurities may preferably be fed into the waste reservoir 2426.

[0088] Furthermore, dashed arrow 2462 indicates that additional substances can be optionally fed into the CVD SiC reactor 850a (and similarly, into the CVD SiC reactor 850b). These additional substances can be, for example, carbon-containing molecules (particularly CH4 (methane)) and / or H2 (hydrogen). Furthermore, chlorosilanes and a second fluid can be fed into the CVD SiC reactor via a common gas inlet. This additional substance can also be fed into the same inlet in the CVD SiC reactor 850 via chlorosilanes and / or a second liquid. This also applies to the following figures.

[0089] Figure 4 Further detailed examples of the system according to the invention are shown. An additional CVD SiC reactor 850b is not shown in the figures; however, it must be understood that, if required by the additional CVD SiC reactor 850b, a portion of the treated exhaust gas can be additionally or alternatively supplied to such an additional CVD SiC reactor 850b (this also applies to the additional figures).

[0090] Even if a waste reservoir 2426 is installed after the metal removal device 2425, the separation unit 602 can still be connected to the waste reservoir 2426 or another waste reservoir.

[0091] The additional separation unit 612 preferably includes a metal removal device 2425, which preferably removes remaining metal impurities from the first fluid 624. The first fluid 624 is preferably fed from the metal removal device 2425 to the STC and TCS distribution device 2421. Alternatively, the first fluid can be fed into the CVD SiC reactor 850a. The STC is preferably stored in the STC reservoir 2422, and the TCS is preferably stored in the TCS reservoir 2424.

[0092] According to another preferred embodiment, an additional separation unit 612 may be configured to reduce the amount of metallic impurities (particularly B, Al, P, Ti, V, Fe, and / or Ni) in the first fluid 624, particularly the chlorosilane, to below 20 ppmw, preferably below 10 ppmw, particularly for one or more of B, Al, P, Ti, V, Fe, and / or Ni, very preferably below 5 ppmw, particularly for one or more of B, Al, P, Ti, V, Fe, and / or Ni, most preferably below 1 ppmw, particularly for one or more of B, Al, P, Ti, V, Fe, and / or Ni. The removed metallic impurities may preferably be fed into waste reservoir 2426.

[0093] TCS and / or STC can be fed from STC reservoir 2422 and / or TCS reservoir 2424 into CVD SiC reactor 850. The volume or mass of STC and / or TCS fed into CVD SiC reactor is preferably controlled, particularly by means of a mass flux controller or a mass flux controller for STC and / or a mass flux controller for TCS.

[0094] Figure 5 The diagram schematically illustrates that the separation unit 602 is not connected to or is not directly connected to the waste reservoir 2426. In particular, the separation unit 602 may not be configured to separate or remove metallic impurities. Alternatively, the amount of metallic impurities in the generated chlorosilane can be reduced to less than 20 ppmw, preferably less than 10 ppmw, very preferably less than 5 ppmw, and most preferably less than 1 ppmw, using only an additional separation unit 612.

[0095] Figure 6 The diagram schematically illustrates that the Si supply unit 2432 can be part of the system of the present invention. The Si supply unit 2432 is preferably a Si reservoir for storing and supplying Si particles. Alternatively, the Si supply unit 2432 can be a crushing device, particularly a jaw crusher and / or a water pulse crusher. However, the Si supply unit 2432 may also include a Si reservoir for storing and supplying Si particles and a crushing device for crushing Si, particularly a jaw crusher and / or a water pulse crusher.

[0096] Figure 7The diagram schematically illustrates that, in addition to the Si supply unit 2432, an HCl supply unit 2434 may also be provided for supplying HCl (particularly from an HCl reservoir) to the reactor 2416. The HCl supply unit 2434 may also be present even if the Si supply unit 2432 is not provided. This HCl supply unit 2434 can be used to add the amount of HCl removed from the system, particularly via the exchange device 2460 (see...). Figure 2 (or the amount of HCl removed by the removal device.)

[0097] Figure 8 The diagram shows a Si supply unit 2432, an HCl supply unit 2434, and an exhaust gas storage unit 2450 connected to reactor 2416. It must be understood that the Si supply unit 2432, HCl supply unit 2434, and exhaust gas storage unit 2450 are optional. However, according to the invention, one, two, or all of them may be present. The exhaust gas storage unit 2450 is configured to store and supply exhaust gas, particularly exhaust gas above its condensation temperature. This embodiment is advantageous because a continuous supply of exhaust gas to reactor 2416 can be established during the start-up and / or shutdown of the CVD SiC reactor 850. Therefore, the production of chlorosilanes is possible even if the CVD SiC reactor does not supply exhaust gas.

[0098] Alternatively, HCl can be supplied during the start-up and / or shutdown of the CVD SiC reactor 850, because HCl reacts with Si to form chlorosilanes.

[0099] Alternatively or alternatively, chlorosilanes, particularly TCS, are supplied to reactor 2416, particularly from TCS reservoir 2422.

[0100] Alternatively, chlorosilane (especially TCS, preferably from TCS reservoir 2422) and HCl (preferably from HCl supply unit 2434) can be supplied to reactor 2416 in combination.

[0101] Furthermore, the supply of HCl, exhaust gases, or chlorosilanes can lead to the production of even more chlorosilanes.

[0102] Carbon-containing molecules (especially methane) and H2 can also be supplied to the reactor, particularly to keep the reactor idle. It is also advantageous to heat reactor 2416, and especially reactor chamber 2419, in this case.

[0103] All these optional or additional supply steps are advantageous because reactor 2416 does not need to be shut down during the start-up or shutdown of the CVD SiC reactor.

[0104] Reference numeral 2428 indicates a paused / reduced feed of the exhaust gas mixture from the CVD SiC reactor, for example, due to a pause or reduction during the start-up or shutdown phase.

[0105] Figure 9 The second fluid 626 is shown to be fed through absorber assembly 2436 to remove phosphorus, dust, and / or metallic impurities. The removed material is preferably fed into scrubber 2438, and the resulting material can be combusted in combustion unit 2440, particularly in a flare. Combustion unit 2440 is preferably used to provide heat to heat reactor 2416, especially when no exothermic reaction occurs inside reactor 2416, or when the reactor is in the start-up phase.

[0106] Combination Figures 2 to 9 The described system is capable of performing the preferred method of the present invention for producing SiC. The method preferably includes at least the following steps:

[0107] An exhaust gas mixture 2400 is provided, preferably generated during SiC production, and very preferably during CVD SiC production, wherein at least a first component of the exhaust gas mixture is HCl, wherein a second component of the exhaust gas mixture consists of exhaust gas chlorosilanes, particularly STC and / or TCS, wherein a third component 2401 of the exhaust gas mixture 2400 comprises or consists of H2 2402, and wherein a fourth component of the exhaust gas mixture 2400 comprises or consists of at least one carbon-containing molecule (particularly methane) 2404. The method preferably further includes the step of providing solid Si inside the reactor chamber, wherein the solid Si contains metallic impurities greater than 1000 ppmw. The method preferably further includes the step of conveying at least the second component and the third component and / or the first component of the exhaust gas mixture 2400 into the reactor chamber. The method preferably further includes the step of generating chlorosilane inside the reactor chamber by reacting a second component (particularly STC and / or TCS) of the exhaust gas mixture and a third component 2401 of the exhaust gas mixture 2400 with solid Si, and / or by reacting a first component of the exhaust gas mixture 2400 with solid Si.

[0108] The method preferably further includes the steps of: conveying at least the generated chlorosilane 2394 to a process chamber 856a of a CVD SiC production reactor 850a, and conveying at least one carbon-containing molecule to the CVD SiC production reactor 850a, and producing SiC inside the process chamber 856a of the CVD SiC production reactor 850a by reacting the generated chlorosilane with C from the at least one carbon-containing molecule on at least one deposition surface. Alternatively, the method preferably further includes the steps of: conveying at least the generated chlorosilane 2394 to a process chamber 856b of a further CVD SiC production reactor 850b, and conveying at least one carbon-containing molecule to the further CVD SiC production reactor 850b, and producing SiC inside the process chamber 856b of the further CVD SiC production reactor 850b by reacting the generated chlorosilane with C from the at least one carbon-containing molecule on at least one deposition surface.

[0109] Regarding the foregoing figures, the method according to the invention can be divided into a phase "during CVD SiC reactor operation" and a phase "during start-up or shutdown". Additional or alternative features (in combination) are described below by way of example. Figures 2 to 9 (Description of the two stages).

[0110] During SiC deposition in a SiC CVD reactor, the process gas preferably comprises or consists of STC, TCS, H2, CH4, and HCl. The process gas exits the SiC CVD reactor chamber as an "emission gas" and is preferably cooled to approximately 200°C by means of a heat exchanger. The emission gas stream is entirely maintained in the gas phase. The entire emission gas stream is then continuously fed into the reactor, particularly a bed reactor, and preferably a fixed-bed reactor. The reactor preferably comprises a steel vessel, particularly with dimensions of: a height greater than 5 m, preferably 8 m or greater, and very preferably 10 m or greater, and a diameter of 1 m or greater, particularly 1.5 m or greater, or preferably 2 m or greater, or between 1.7 m and 2.3 m. A silicon bed is present in the reactor. The emission gas is introduced into the lower part of the reactor, which allows the emission gas to flow optimally through the silicon bed. Contact between the gas phase and silicon leads to an exothermic chemical reaction, forming a new gaseous mixture of STC, TCS, H2, CH4, and HCl. In this mixture, the HCl content is significantly reduced, while the content of chlorosilanes containing STC and / or TCS, or composed of STC and / or TCS, increases. The silicon bed is preferably maintained at a temperature of 400 to 450°C and a pressure between 1.2 bar and 2 bar, particularly 1.5 bar, which ensures optimal levels of HCl conversion. Within the reactor, the proportion of chlorosilanes in the gas phase increases with silicon degradation. To cool the reactor chamber, the reactor is preferably operated with a cooling water jacket.

[0111] Furthermore, a liquid chlorosilane mixture of STC and / or TCS can be introduced into the upper part of the reactor. On the one hand, this process is used to cool the reaction chamber and thus control the reaction temperature; on the other hand, the metal chloride components (e.g., ferric chloride and aluminum chloride) are thereby converted from the gas phase into solid particulate form.

[0112] After the exhaust gas leaves the reactor, the solid components formed are preferably separated from the gaseous fluid, particularly by means of a solid separation system that preferably uses a cyclone separator and / or filter.

[0113] In addition, a downstream gas scrubber can be provided, which is preferably operated using liquid chlorosilane. This embodiment is advantageous because it ensures that even very small solid components can be washed out of the gas stream, thereby further reducing the metal chloride content in the fluid.

[0114] After separating the solid components from the gas stream, the condensable components in the process gas are preferably liquefied by cooling. The liquid phase is preferably separated and mainly contains dissolved portions of chlorosilanes STC and TCS, as well as HCl, H2 and CH4, and trace components of high-boiling chlorosilanes (e.g., hexachlorodisilane) and metal chlorides.

[0115] The gas phase preferably mainly comprises or consists of H2, CH4, and small amounts of HCl, STC, and TCS.

[0116] To further purify chlorosilanes from metal chlorides and separate them into individual components STC and TCS, it is preferable to perform one or more additional distillation steps on the liquid phase and collect the purified STC and / or TCS separately in a vessel.

[0117] After the liquid components are separated, the gas phase is preferably returned to the CVD SiC reactor or another CVD SiC reactor or storage unit, particularly a tank.

[0118] During the start-up or shutdown phase of a SiC CVD reactor, preferably no process gas leaves the SiC CVD reactor chamber. If it is taken directly from the CVD SiC reactor, no CVD SiC reactor exhaust gas stream can be continuously introduced into the reactor.

[0119] The reactor is preferably a steel vessel with a height of 10 m and a diameter of approximately 2 m. Bulk silicon 2398 is present in reactor 2416. A gas mainly consisting of or composed of H2 and CH4, and small amounts of STC, TCS, and HCl, is introduced into the reactor, particularly in the lower part of reactor 2416. The bulk silicon 2398 is preferably maintained at a temperature of 400 to 450 °C and a pressure of 1.5 bar. Due to the lack of an exothermic reaction between silicon, HCl, and chlorosilanes, the gas is preferably heated to a temperature between 800 °C and 700 to 900 °C, particularly between 750 °C and 850 °C, especially at or before the gas inlet, to heat the bulk silicon 2398 in the reactor.

[0120] After the exhaust gas leaves the reactor, the solid components formed are preferably separated from the gaseous fluid, particularly by means of a solid separation system that preferably uses a cyclone separator and / or filter.

[0121] In addition, a downstream gas scrubber can be provided, which is preferably operated using liquid chlorosilane. This embodiment is advantageous because it ensures that even very small solid components can be washed out of the gas stream, thereby further reducing the metal chloride content in the fluid.

[0122] After separating the solid components from the gas stream, the condensable components in the process gas are preferably liquefied by cooling. The liquid phase is preferably separated and mainly contains dissolved portions of chlorosilanes STC and TCS, as well as HCl, H2 and CH4, and trace components of high-boiling chlorosilanes (e.g., hexachlorodisilane) and metal chlorides.

[0123] The gas phase preferably mainly comprises or consists of H2, CH4, and small amounts of HCl, STC, and TCS.

[0124] To further purify chlorosilanes from metal chlorides and separate them into individual components STC and TCS, it is preferable to perform one or more additional distillation steps on the liquid phase and collect the purified STC and / or TCS separately in a vessel.

[0125] After the liquid components are separated, the gas phase is preferably returned to the CVD SiC reactor or another CVD SiC reactor or storage unit, particularly a tank.

[0126] Therefore, the present invention relates to a SiC and chlorosilane production system 2540, comprising: at least one CVD SiC production reactor 850, particularly a SiC fluidized bed reactor 850a, particularly the reactor according to claim 4, and a chlorosilane production unit 2550, wherein the chlorosilane production unit 2550 comprises at least a bed reactor 2416, particularly a fixed bed reactor or a fluidized bed reactor, for generating chlorosilanes by reacting at least one component of an exhaust gas mixture provided via an exhaust gas outlet 216 of the CVD SiC production reactor 850 with Si, wherein the other components of the exhaust gas mixture comprise at least H2 and carbon-containing molecules (particularly methane), and wherein Si is provided as a solid 2398 inside the bed reactor 2416. List of reference numerals

[0127] 216 Emission Gas Outlet

[0128] 602 Separation Unit

[0129] 612 Other separation units

[0130] 624 First Fluid

[0131] 626 Second Fluid

[0132] 850a refers to a manufacturing apparatus, CVD unit, CVD reactor, or CVD SiC production reactor, particularly a SiCPVT source material production reactor.

[0133] 850b Other manufacturing equipment, CVD units, CVD reactors, or CVD SiC production reactors, especially SiC PVT source material production reactors.

[0134] 851 First feeding device or first feeding medium source

[0135] 852 Second feeding device or second feeding medium source

[0136] 853 The third feeding device, or the third feeding medium source, or a separate carrier gas feeding medium source.

[0137] 854 Mixing Device

[0138] 855 Evaporator Unit / Gas Preheating Unit

[0139] 856 Process Chamber

[0140] 866 intake unit

[0141] 2394 Chlorosilane

[0142] 2398 Si / Solid-state Si

[0143] 2400 exhaust gas mixture

[0144] 2401 Other components of the exhaust gas mixture

[0145] 2400 exhaust gas duct

[0146] 2412 First reservoir and / or conductive element

[0147] 2414 Second reservoir and / or conductive element / pipe or hose

[0148] 2416 Bed Reactor

[0149] 2417 Gas Inlet

[0150] 2418 Part 1

[0151] 2419 Reactor Chamber

[0152] 2420 Part Two

[0153] 2421 STC and TCS distribution device

[0154] 2422 STC memory

[0155] 2424 TCS storage

[0156] 2425 Metal Removal Device

[0157] 2426 Waste Storage

[0158] 2428 Suspended / Reduced Emission Gas Mixture Feed

[0159] 2430 TCS reservoir path to bed reactor

[0160] 2432 Si supply unit

[0161] 2434 HCl Supply Unit

[0162] 2436 Second Fluid Processing Unit / Absorber

[0163] 2438 Washer

[0164] 2440 Combustion Unit / Flame

[0165] 2450 Emission Gas Storage Tank

[0166] 2460 Switching Unit

[0167] 2462 Dashed arrow / Input path

[0168] 2500 Reaction Zone

[0169] 2501 Upper end of reaction zone / fluid outflow section

[0170] 2502 Lower end of the reaction zone / fluid inflow section

[0171] 2504 heating unit

[0172] 2506 Seed Crystal Particle Supply Unit

[0173] 2507 Actuator for continuous or stepwise transfer of seed crystal particles

[0174] 2508 Seed Crystal Particles

[0175] 2509 The orientation of the seed crystal particles inside the process chamber

[0176] 2510 growing particles

[0177] 2512 Grains that have completed growth

[0178] 2514 Orientation of the fully grown particles

[0179] 2516 Adiabatic Section

[0180] 2518 Rotary unloading device

[0181] 2520 Maximum extension between two surface points

[0182] 2522 Conduit or tubing

[0183] 2524 Top wall section

[0184] 2540 SiC and Chlorosilane Production System

[0185] 2550 Chlorosilane Production Unit

Claims

1. A CVD SiC production reactor (850), particularly a SiC fluidized bed reactor (850a), comprising at least: A process chamber (856) that at least surrounds a reaction zone (2500) for growing SiC. The intake unit (866) is used to feed one or more feed media into the reaction zone of the process chamber for generating or providing a source medium and for generating a fluid flow. A seed crystal particle supply unit (2506) is used to supply seed crystal particles to the reaction zone, wherein the seed crystal particles have a diameter of at least 20µm to 1000µm. The reaction zone (2500) and the air intake unit (866) are configured to form the fluid flow in such a way that the seed crystal particles (2508), in particular a specified amount of seed crystal particles (2508), are held within the reaction zone (2500) for a specified minimum time of more than 5 seconds, in particular more than 30 seconds, for the purpose of forming SiC particles (2512) by accumulating SiC. as well as An induction heating unit (2504) is arranged at least in a segment surrounding the reaction zone (2500) for heating the source medium and seed crystal particles (2508) inside the reaction zone (2500) to a temperature in the range of 1300°C to 2000°C.

2. The CVD SiC production reactor according to claim 1, Its features The air intake unit (866) is connected to at least one feed medium source (851).

3. The CVD SiC production reactor according to claim 1, Its features The air intake unit (866) is connected to at least two feed medium sources (851, 852).

4. The CVD SiC production reactor according to claim 1, 2, or 3, Its features The reaction zone (2500) is at least partially surrounded by one or more insulating sections (2516), wherein the one or more insulating sections (2516) are arranged in a tubular manner to form a fluid inflow section (2502) for allowing fluid to flow into at least a portion of the reaction zone (2500) and a fluid outflow section (2501) for allowing fluid to flow out of the at least a portion of the reaction zone (2500).

5. The CVD SiC production reactor according to any one of the preceding claims, Its features A gas preheating unit (855) is provided for heating the one or more feed media to a temperature above 700°C, particularly above 1100°C, wherein the gas preheating unit (855) is configured to preheat the one or more feed media before feeding them into the reaction zone by means of the gas inlet unit (866) to generate the fluid flow. and / or At least one rotary discharge device (2518) is provided in the section below the reaction zone (2500) for removing SiC particles (2512). and / or The seed crystal particle supply unit (2506) is configured to continuously feed seed crystal particles (2508) into the process chamber (856).

6. The CVD SiC production reactor according to any one of the preceding claims, Its features An exhaust gas outlet (216) is provided for removing from the process chamber (856) the exhaust gas mixture generated by the reaction between the fluid flow of the one or more feed media and the seed crystal particles in the reaction zone.

7. The CVD SiC production reactor according to claim 1, Its features The Si and C feed medium source (851) provides at least Si and C, especially SiCl3 (CH3), and the carrier gas feed medium source (853) provides a carrier gas, especially H2.

8. The CVD SiC production reactor according to claims 3 to 6, Its features The Si feed medium source (851) provides at least Si, and the C feed medium source (852) provides at least C, particularly natural gas, methane, ethane, propane, butane and / or acetylene, and the carrier gas medium source (853) provides a carrier gas, particularly H2.

9. A SiC and chlorosilane production system (2540), comprising: At least one CVD SiC production reactor (850) according to any one of claims 1 to 8, particularly a SiC fluidized bed reactor (850a). as well as A chlorosilane production unit (2550), wherein the chlorosilane production unit (2550) comprises at least a bed reactor (2416), particularly a fixed bed reactor or a fluidized bed reactor, for generating chlorosilanes by reacting at least one component of an exhaust gas mixture supplied via an exhaust gas outlet (216) of the CVD SiC production reactor (850) with Si, wherein the other component of the exhaust gas mixture comprises at least H2 and carbon-containing molecules, particularly methane, and wherein Si is provided as a solid (2398) inside the bed reactor (2416).

10. The SiC and chlorosilane production system according to claim 9, Its features The chlorosilane production unit (2550) includes a separation unit (602), particularly a distillation column, for separating one or more metals, particularly B, Al, Fe and / or P, from the chlorosilanes, particularly STC and / or TCS, generated by the bed reactor (2416).

11. The SiC and chlorosilane production system according to claim 9 or 10, Its features The chlorosilane production unit (2540) includes a fluid outlet, which is connected to the inlet unit (866) of the CVD SiC production reactor (850) via a pipe or hose (2414) for conducting the generated chlorosilane, thereby feeding the generated chlorosilane into the process chamber (856a) of the CVD SiC production reactor (850), and / or connected to the inlet unit of another CVD SiC production reactor (850b), thereby feeding the generated chlorosilane into the process chamber (856b) of the other CVD SiC production reactor (850b).

12. A method for producing silicon carbide (SiC), It includes at least the following steps: A CVD SiC production reactor (850) is provided, particularly a CVD SiC production reactor according to any one of claims 1 to 7, wherein the CVD SiC production reactor (850) includes a process chamber (856), wherein the process chamber (856) at least surrounds a reaction zone (2500) for growing SiC. One or more feed media are fed into the reaction zone (2500) of the process chamber (856) via the intake unit (866) for the purpose of generating or providing a source medium and for generating a fluid flow. Seed crystal particles (2508) are provided into the reaction zone (2500), particularly by means of a seed crystal particle supply unit (2506), wherein the seed crystal particles (2508) have a diameter of at least 20µm to 1000µm. The fluid flow is formed in such a way that the seed crystal particles (2508), in particular a specified amount of seed crystal particles, are held inside the reaction zone (2500) for a specified minimum time of more than 5 seconds, in particular more than 30 seconds, in order to form SiC particles (2512) by accumulating SiC. as well as The source medium and seed crystal particles (2508) inside the reaction zone (2500) are heated to a temperature in the range of 1300°C to 2000°C.

13. The method according to claim 12, Its features The air intake unit (866) is connected to at least one feed medium source (851).

14. The method according to claim 12, Its features The air intake unit (866) is connected to at least two feed medium sources (851, 852).

15. The method according to any one of claims 12, 13 or 14, Its features The seed crystal particles (2508) are made of or comprise at least 90% by mass of C, particularly at least 98% by mass of C, and preferably at least 99% by mass of C, and very preferably at least 99.9% by mass of C, and most preferably at least 99.99% by mass of C.

16. The method according to any one of claims 12, 13 or 14, Its features The seed crystal particles (2508) are made of SiC or comprise at least 90% by mass of SiC, particularly at least 98% by mass of SiC, and preferably at least 99% by mass of SiC, and very preferably at least 99.9% by mass of SiC, and most preferably at least 99.99% by mass of SiC.

17. The method according to any one of claims 12 to 16, Its features The seed crystal particles (2508) are continuously supplied to the process chamber (856) by means of the seed crystal particle supply unit (2506). and / or Before the feed medium or multiple feed media are fed into the reaction zone (2500) by means of the air intake unit (866) to generate the fluid flow, the feed medium or multiple feed media are preheated to a temperature above 700°C, particularly above 1100°C, by means of the gas preheating unit (855). and / or SiC particles (2512) are removed from the process chamber (856) by means of at least one rotary unloading device (2518).

18. The method according to any one of claims 12 to 17, Its features The mixture of exhaust gases generated by the reaction between the fluid flow of one or more feed media and the seed crystal particles (2508) in the reaction zone (2500) is removed from the process chamber (856) via the exhaust gas outlet (216).

19. The method according to claim 18, Its features At least the first component of the exhaust gas mixture is HCl. The second component of the exhaust gas mixture is composed of exhaust gas chlorosilanes, particularly STC and / or TCS. The third component (2401) of the emission gas mixture (2400) comprises or is composed of H2 (2402). as well as The fourth component of the emission gas mixture (2400) includes at least one carbon-containing molecule, particularly methane (2404), or is composed of at least one carbon-containing molecule, particularly methane (2404).

20. The method according to claim 19, Its features Steps Solid Si is provided inside the reactor chamber (2419) of the chlorosilane production unit (2550), wherein the solid Si (2398) includes metallic impurities greater than 1000 ppmw. At least a second component of the exhaust gas mixture (2400), and preferably a second component and a third component of the exhaust gas mixture (2400), and more than one component of the exhaust gas mixture, and particularly preferably at least a second component and a first component of the exhaust gas mixture (2400), and most preferably all components of the exhaust gas mixture (2400), are delivered to the reactor chamber (2419). Chlorosilanes are generated inside the reactor chamber (2419) by reacting a second component of the exhaust gas mixture, particularly STC and / or TCS, with the solid Si (2398), and preferably by reacting at least a second component and a first component of the exhaust gas mixture.

21. The method according to claim 20, Its features Remove the generated chlorosilane from the chlorosilane production unit (2550).

22. The method according to claim 21, Its features At least the generated chlorosilane (2394) removed from the chlorosilane production unit is transferred to the process chamber (856a) of the CVD SiC production reactor (850a), and At least one carbon-containing molecule is transferred into the CVD SiC production reactor (850a). SiC is produced inside the process chamber (856a) of the CVD SiC production reactor (850a) by reacting the generated chlorosilane with C from at least one carbon-containing molecule on at least one deposition surface. or At least the generated chlorosilane (2394) removed from the chlorosilane production unit is transferred to the process chamber (856b) of another CVD SiC production reactor (850b), and At least one carbon-containing molecule is transferred to the additional CVD SiC production reactor (850b). SiC is produced inside the process chamber (856) of the additional CVD SiC production reactor (850b) by reacting the generated chlorosilane with C from at least one carbon-containing molecule on at least one deposition surface.

23. The method according to claim 20, 21 or 22, Its features The step of reducing the amount of metal impurities in the generated chlorosilane to less than 20 ppmw, and preferably less than 10 ppmw, and very preferably less than 5 ppmw, and most preferably less than 1 ppmw is divided into at least a first removal step and a second removal step, wherein a first amount of metal impurities is removed in the first removal step and a second amount of metal impurities is removed in the second removal step.

24. The method according to claim 23, Its characteristics include the following steps: The generated chlorosilane (2394) and the third component (2401) of the emission gas mixture (2400) and the fourth component of the emission gas mixture (2400) are separated into a first fluid (624) and a second fluid (626). The steps of reducing the amount of metallic impurities in the generated chlorosilane to less than 20 ppmw, and preferably less than 10 ppmw, and very preferably less than 5 ppmw, and most preferably less than 1 ppmw, as well as the steps of separating the generated chlorosilane (2394), the third component (2401) of the emission gas mixture (2400), and the fourth component of the emission gas mixture (2400) into a first fluid (624) and a second fluid (626) are performed by a separation unit. The first removal step, as well as the steps of separating the generated chlorosilane (2394), the third component (2401) of the emission gas mixture (2400), and the fourth component of the emission gas mixture (2400) into a first fluid (624) and a second fluid (626), are performed by a separation unit. as well as The second removal step is performed by another device, particularly another separation unit, especially a chlorosilane distillation column.

25. The method according to any one of claims 13 or 15 to 24, Its features The Si and C feed medium source (851) provides at least Si and C, especially SiCl3 (CH3), and the carrier gas feed medium source (853) provides a carrier gas, especially H2.

26. The method according to any one of claims 14 to 24, Its features The Si feed medium source (851) provides at least Si, and the C feed medium source (852) provides at least C, particularly natural gas, methane, ethane, propane, butane and / or acetylene, and the carrier gas medium source (853) provides a carrier gas, particularly H2.

27. A SiC and chlorosilane production system (2540). It includes at least one A chlorosilane production unit (2550), wherein the chlorosilane production unit (2550) comprises at least a bed reactor (2416), particularly a fixed-bed reactor or a fluidized-bed reactor, for generating chlorosilanes by reacting at least one component of an exhaust gas mixture supplied via an exhaust gas outlet (216) of a CVD SiC production reactor (850) with Si, wherein the other component of the exhaust gas mixture comprises at least H2 and carbon-containing molecules, particularly methane, and wherein Si is provided as a solid (2398) inside the bed reactor (2416). as well as The CVD SiC production reactor (850), particularly the SiC fluidized bed reactor (850a), for producing SiC according to any one of claims 1 to 8. The chlorosilane production unit (2550) and the CVD SiC production reactor (850) are connected at least via conduits, particularly pipes, for feeding chlorosilane generated by means of the chlorosilane production unit (2550) into the CVD SiC production reactor (850) for the production of SiC.

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