contacting the fine particles with a gas phase in a stirred bed reactor

Abstract

The invention relates to a process for producing a product by contacting particles with a gas phase in a stirred fixed bed, wherein the treatment of the particles takes place in a treatment zone of a reactor, the gas flows through the reactor and the particles are turned over by means of a stirrer, which during the contacting of the particles with the gas phase in the treatment zone is close to the wall, wherein if in equation 1 the stir unit is close to the wall, for half of all h values the wall clearance W(h) in the treatment zone is W(h) > 0.9, wherein u R (h) is the outer circumference of the stir unit at the cross section for the vertical coordinate h and u B (h) is the inner circumference of the reactor at the cross section for the vertical coordinate h.

Description

Technical Field

[0001] This invention relates to a method for producing a product by contacting particles with a gas phase in a stirred fixed bed, wherein the particle treatment occurs in a process zone of a gas-traversed reactor and the particles are circulated in the process zone by a close-clearance stirrer during contact with the gas phase, wherein the stirrer mechanism is close-clearance. Background Technology

[0002] Gas-phase reactions on solid surfaces are an integral part of the modern world. For example, the treatment of exhaust gases from internal combustion engines occurs on the surface of a rhodium catalyst. Many reactions between gases and solid surfaces also take place in the chemical industry. Therefore, it is generally very important that as much solid surface as possible be in contact with the gas, so that these reactions can proceed efficiently and with high space-time yields. Typically, various methods have been developed in the past for contacting solids with gases. These methods differ primarily in the morphology of the solids used. The smaller the particles used and the higher the available solid surface area in the method, the greater the technical requirements become.

[0003] Various reactor types are known for commercial applications of gas-solid reactions. Fluidized bed reactors (FBRs) and rotary kilns, for example, have the disadvantage of not being suitable for all particle sizes. Especially for very fine particles, reaction with the gas phase is impossible without considerable technical complexity. Geldart C-type particles cannot be processed by available methods. Geldart C-type particles are characterized by their small size (d... 90 <20 μm) and exhibit strong interparticle attraction, making clean fluidization difficult. Typical examples are powders or fine dust, such as abrasive debris from solids processing. In elongated reactors, these particle beds have a strong tendency to form bubbles, while simultaneously lifting the entire particle bed above them. In shallow fluidized beds, chimneys or channels can form between the distribution substrate and the bed surface, causing the gas phase to no longer flow uniformly across other areas of the particle bed [D. Geldart, Types of gas fluidization, Powder Technology 7 (1973) 258]. Therefore, good fluidization of such particles is usually achieved only through mechanical energy input via a stirrer or vibrator.

[0004] It is generally known that good contact between porous solids and fluid precursors is necessary in multiphase reaction systems containing at least one particle bed [F. Schüth Chem. Unserer Zeit 2006, 40, 92-103].

[0005] An example of such a method that can be described is the production of silicon-carbon composite materials for lithium-ion batteries.

[0006] For example, US10,147,950B2 describes the deposition of silicon from silane SiH4 in porous carbon at elevated temperatures of 300°C to 900°C, preferably with particle agitation, in a rotary kiln or equivalent furnace type via CVD (“chemical vapor deposition”) or PE-CVD (“plasma-enhanced chemical vapor deposition”). A mixture of 2 mol% silane and nitrogen is used as the inert gas. The low concentration of the silicon precursor in the gas mixture results in a very long reaction time. Furthermore, the bed-to-reactor volume ratio in the rotary kiln is generally very unfavorable, as otherwise a considerable amount of particulate matter would be emitted through the gas stream.

[0007] Another method for conducting gas-solid reactions is a gas fluidized bed.

[0008] In a gas fluidized bed, the solid particle bed is loosened and carried by an upwardly flowing gas to such an extent that the solid layer generally exhibits liquid-like behavior [VDI-]. [VDI Heat Atlas],11thedition,Section L3.2 und Druckverlust in Wirbelschichten [Types of Flow and Pressure Drop in Fluidized Beds, pp.1371-1382, SpringerVerlag, Berlin Heidelberg, 2013].

[0009] A gas fluidized bed is also commonly referred to as a fluidized bed. The operation that produces a fluidized bed is also called fluidization or fluidizing.

[0010] In a gas fluidized bed, solid particles are very well dispersed. This results in a very high contact area between the solid and the gas, which can be ideally used for energy and mass transfer processes. Gas fluidized beds are generally characterized by very good mass and heat transfer operation and a uniform temperature distribution. The quality of the mass and heat transfer methods is crucial to the homogeneity of the products obtained from reactions in a fluidized bed and can be related to the homogeneity of the fluidization state. Therefore, the formation of a homogeneous fluidized bed or homogeneous fluidization state is necessary for producing products with the same product characteristics using fluidized bed methods.

[0011] Fluidization properties can be classified according to particle size and solid density. A particle size d... 90 <20μm and with a density difference between particles and gas >1000kg / m³ 3 The particles are covered by Geldart C-type (cohesive) [D. Geldart, Types of Gas Fluidization, Powder Technology 7 (1973) 285]. Geldart C-type particles are characterized by their difficulty in transitioning to a fluidized state. Due to their small particle size, the influence of interparticle attraction is of the same order of magnitude or greater than the force exerted on the primary particles by the airflow. Accordingly, effects such as the lifting of the fluidized bed as a whole and / or channel formation occur. In the case of channel formation instead of a fluidized bed, a tube is formed in the particle bed through which the fluidizing gas preferentially flows, while there is no flow through most of the bed. Therefore, no uniformity of fluidization is achieved. If the gas velocity increases to a level much higher than the minimum fluidization velocity of the primary particles in the bed, agglomerates composed of individual particles form over time, and these agglomerates can be fully or partially fluidized. The typical behavior is the formation of layers of agglomerates of different sizes. In the lowest layer, directly above the inflow substrate, there are very large agglomerates that move very little (if at all). In the upper layers, smaller fluidized agglomerates exist. The smallest agglomerates are present in the uppermost layer, and these agglomerates are partially entrained by the airflow, which is problematic from a process engineering point of view. Another characteristic of this particle bed fluidization is the formation of large bubbles and the low expansion of the fluidized bed. In the English literature, this behavior is referred to as “agglomerate bubbling fluidization” (ABF). [Shabanian, J.; Jafari, R.; Chaouki, J., Fluidization of Ultrafine Powders, IRECHE., vol.4, N.1, 16-50].

[0012] Those skilled in the art will understand that ABF fluidized beds are unsuitable for producing substances with homogeneous properties due to the inhomogeneity within the fluidized bed and the associated inhomogeneous mass and heat transfer conditions.

[0013] Therefore, for example, in GB 2580110 B2, fluidizing particles with a size greater than 50 μm is performed in a fluidized bed containing 1.25% silane by volume. 50 The resulting particles are then ground to a desired target size of <20 μm. However, after the reaction, these particles must be milled to this target size. Fluidization of particles <20 μm will result in strong agglomeration and uneven penetration of the porous carbon particles in this fluidized bed.

[0014] Fluidization aids are known to be used to convert particles <20 μm in agglomerate form into a predominantly homogeneous fluidized bed. US 7,658,340 B2 describes, for example, the introduction of additional force components such as vibrational, magnetic, acoustic, rotational, or centrifugal forces, or combinations thereof, in addition to the forces applied by the fluidizing gas, to influence the size of agglomerates composed of SiO2 nanoparticles (Geldart C type) in a fluidized bed in order to form a predominantly homogeneous fluidized bed.

[0015] Cadoret et al. [Cadoret, L.; Reuge, N.; Pannala, S.; Syalmal, M.; Rossignol, C.; Dexpert-Ghys, J.; Coufort, C.; Caussat, B.; Silicon Chemical Vapor Deposition on macro and submicron powders in a fluidized bed, Powder Technol., 190, 185-191, 2009] describe the deposition of silicon from silane SiH4 onto submicron-sized, non-porous titanium oxide particles in a vibrating fluidized bed reactor. In the fluidized bed, the vibration input confines the agglomerates to a size range of 300 to 600 μm.

[0016] Fluidized bed processes without fluidizing agents are unsuitable for silicon insertion / deposition processes in porous matrix particles because particles <20 μm in size cannot be fluidized uniformly. Due to the non-uniform fluidized bed, a uniform product cannot be produced.

[0017] Fluidized bed processes with fluidization aids are disadvantageous for the contact between Geldart C-class particles and the gas phase because fluidizing particles <20 μm requires significant technical complexity. This additional complexity is associated with high investment and maintenance costs.

[0018] Another drawback of inserting exemplary silicon into porous particles via a fluidized bed process with fluidizing aids is that the properties of the primary particles, such as particle density or surface quality, change as the process progresses. These properties have an unknown influence on agglomerate formation; such formation should be known for the process design. Homogeneous process conditions cannot be guaranteed throughout the entire duration of the process.

[0019] Another drawback of fluidized bed technology is that the fluidization of agglomerates composed of primary porous particles requires airflow, which leads to the discharge of primary particles and / or relatively small agglomerates.

[0020] A fundamental drawback of fluidized bed technology is that the fluidizing gas flow used to form a homogeneous fluidized bed depends on the size of the particles or agglomerates within the fluidized bed. Therefore, the metered amount of reactant gas and the contact time between the reactant gas and the porous particles depend on the fluidization and mixing state of the particle bed. For example, in fluidized bed processes, the contact time between the gas phase and the particle bed can be increased simply by reducing the gas velocity. However, gas velocity is a critical parameter for ensuring proper fluidization and mixing.

[0021] One possibility for overcoming the drawbacks of fluidized bed technology is to mix the particle bed with the gas phase independently of the flow.

[0022] US2020 / 0240013 A1 describes the deposition of silicon from silicon-containing gas onto particles with an average particle size in the low millimeter range in a stirred bed reactor. Due to the particle size, it can be assumed that the bed material used has very good flowability. With the aid of the described apparatus, the exchange between gas and solid is achieved by using a central stirring screw through which the reactant gas is fed simultaneously through openings in the stirred bed. This application specifically addresses the advantages of handling particles in the millimeter range, because for particles of this size, a large fluidizing gas flow is necessary to convert these particles into a fluidized state.

[0023] However, the stirrer used in US2020 / 0240013 A1 is not suitable for tumbling cohesive particles <20 μm.

[0024] As is known from technical literature, a wide variety of stirring means can be used for particle tumbling in stirred beds [M. Müller, Feststoffmischen [Solids mixing], Chemie Ingenieur Technik 2007, 79, 7]. For example, by using a closely spaced helical stirrer, particles are conveyed laterally upwards in the reactor, resulting in a tumbling flow where the relative movement of particles occurs due to the downward sliding of material. This prevents particles from adhering to the reactor walls.

[0025] The parameter used to describe the motion state of a particle bed is the Froude number (Fr), which represents the ratio of centrifugal force to gravity in a rotating system.

[0026]

[0027] Here, r c It is the characteristic radius associated with the system. For a system with a rotary mixing mechanism, r c This corresponds to the outer radius of the stirring device. For systems with a rotating drum, r... c This is the inner radius of the container. The angular frequency ω = 2πn depends on the rotational speed n of the rotating system. The effect of gravity is considered through the gravitational acceleration g. For small Froude numbers, the gravitational component dominates, resulting in lower radial transport of the material. The particle bed is only insufficiently tumbled. However, for large Froude numbers, the centrifugal component dominates, resulting in excessively strong transport of the material against the container wall. Here, the particle bed is also only insufficiently tumbled.

[0028] One parameter used to describe the contact time between the gas phase and the stirred particle bed is the residence time of the gas phase in the reactor. Average residence time t V It can be used as the reactor volume and the volumetric flow rate of the metering gas phase. Calculate using the quotient:

[0029]

[0030] Another important measure for evaluating homogeneous reaction conditions in a stirred bed reactor is the granular bed turning time t. u Residence time t with silicon precursor v The ratio t u / t v The t-turning time of the particle bed u Calculated as reactor volume V R Volumetric flow rate of the overturned particles The business.

[0031]

[0032] Volumetric flow rate of particles tumbled by the stirring device Defined as the volume of particles displaced tangentially by the stirring device per unit time, and is typically described by the following formula:

[0033]

[0034] The volumetric flow rate of the tumbling particles is the product of the rotational speed *n* and the sum of the tangential displacement volumes of all the individual stirring elements *i* of the agitator. The geometry of each individual stirring element is defined by the distance *r* from its inner edge to the axis of rotation.R,内,i The distance r from the outer edge of the stirring device to the rotation axis R,外,i Furthermore, it is also composed of the upper contour h of the corresponding stirring element. o.i (r) and lower contour h u.i Let's consider (r).

[0035] If the ratio t u / t v Assuming the value is <1, the particle overturning operation is faster than the gas flow through the bed, and therefore a uniform distribution of gas with particles exists. For the ratio t... u / t v When the value is >1, the gas flows through the stirred bed faster than the bed itself rotates. Therefore, regions with different deposition conditions are formed in the stirred bed, leading to a non-uniform product distribution within the bed.

[0036] In this context, the aim is to provide a method for contacting Geldart C particles with the gas phase that is technically easy to implement and does not have the disadvantages of the aforementioned prior art methods, particularly regarding particle emissions, reaction time, and the required infrastructure. Summary of the Invention

[0037] This invention provides a method for producing products by contacting particles with the gas phase in a stirred fixed bed.

[0038] In this process, the particles are processed in the process zone where the gas passes through the reactor, and the particles are tumbled in the process zone by a tightly spaced agitator during contact with the gas phase.

[0039] In Equation 1, the stirring mechanism has a tight gap.

[0040]

[0041] For half of all values ​​of h, the tight gap W(h) in the process zone is W(h) > 0.9, where u R (h) = the outer perimeter of the stirring mechanism in the cross section at height coordinate h, and u B (h) = The inner circumference of the reactor in the cross section at the height coordinate h.

[0042] Surprisingly, it has been found that, as a result of using a close-gap stirring mechanism according to the invention, particles <20 μm are tumbled in the reactor in such a manner, and the gas phase is metered in such a manner that the contact time between the gas phase and the solid is such that the reaction between the gas and the particles is achieved with good conversion, the reaction (catalysis) of the gas at the particles is achieved with good conversion, or the effective physical modification of the particles is achieved.

[0043] Compared to fluidized bed reactors, gas-passing reactors, or stirred-bed reactors (SBRs), have a simpler construction because a smaller amount of gas must be compressed and preheated in the SBR, as the gas is not used for fluidization. This results in lower costs for associated components. In the case of an SBR, the complex control and conditioning techniques used to operate fluidizing agents are not required. Compared to FBRs, SBRs have a smaller build volume because the stirred bed occupies a smaller volume for a given mass. Specific investment costs are also lower.

[0044] Compared with GB 2580110 B2, the method according to the present invention does not require further process steps.

[0045] Compared to fluidized bed reactors, particle overturning is independent of the gas phase supply. Longer residence times are possible, which leads to higher conversion rates, especially when the gas phase reacts with the particles.

[0046] The stirring in the method according to the invention only causes the particles to tumble. The particles are not swirled up by the stirrer.

[0047] The size of the airflow is determined such that the swirling up (vortex) of particles through the airflow in the method according to the invention is minimized, and therefore the particle discharge from the reactor is also minimized. Simultaneously, the airflow is preferably sized such that, in the case of gas-phase reaction with particles, the conversion of the gas phase used is maximized or the physical modification of the particles is effective, while conserving resources.

[0048] Uniform contact between particles and gas can be achieved by appropriately selecting the stirrer speed parameters (expressed as dimensionless Froude numbers) and by using an appropriate metering rate.

[0049] Compared to US2020 / 0240013 A1, the method according to the present invention is improved by using a close-gap agitator.

[0050] As a result of this flipping of the particle bed with a closely spaced agitator, sufficiently good macroscopic mixing of the fluid and solid phases is achieved, which leads to uniform treatment of all particles in the solid phase.

[0051] In the case of gas-phase reaction with particles, a further economic advantage of this method compared to methods not according to the invention lies in the possible higher conversion rate of the gas phase, such as a higher silicon yield in the case of SiH4 deposition to porous particles.

[0052] By means of the method according to the invention, the effective physical modification of particles can be achieved, for example, by means of a close-gap stirring mechanism under constant tumbling of the particle bed, by coating the particle surface with new functionalization, gas-phase reaction with particles, gas-phase reaction at the particles (catalysis), or by means of a close-gap stirring mechanism. The particle bed used can consist of a single type of particles or a mixture of particles.

[0053] The method may also include multiple steps of pretreatment or posttreatment for the particles used. These treatments may be carried out in one reactor or in two or more reactors or towers. If a gaseous product is obtained from the method, the gas phase derived from the method can be separated from the desired product by separation, for example by scrubbing, distillation or condensation.

[0054] If the particles are pretreated in a separate reactor, they can be transferred to another reactor or container, for example, by means of: downpipes, continuous conveyors, flow conveyors / suction or pressure conveying units (e.g., vacuum conveyors, conveyor blowers), mechanical conveyors (e.g., roller conveyors with drives, screw conveyors, circular conveyors, tilting conveyors, bucket conveyors, rotary star valves, chain conveyors, scraper conveyors, belt conveyors, vibrating conveyors), gravity conveyors (e.g., chutes, roller tracks, ball tracks, rails), and also by means of discontinuous conveyors, floor-based and trackless (e.g., Automated vehicles, manual forklifts, electric forklifts), driveless transport systems (DTS), air cushion vehicles, handcarts, electric trolleys, motorized vehicles (tractors, trucks, forklifts, stackers), transfer trays, transfer / lift trays, rack entry devices (with or without converters, capable of following curved paths); floor-based, track-integrated (e.g., factory railroads, rail vehicles); floorless (e.g., trolley tracks), cranes (e.g., bridge cranes, gantry cranes, luffing jib cranes, tower cranes), electric overhead rails, small boat transport systems; fixed (e.g., elevators, lifting platforms and cherry pickers, stepped conveyors).

[0055] In a rotationally symmetric reactor, the tight clearance W(h) of the agitator is defined as the quotient of the perimeters of two plane sections perpendicular to the axes of rotation of the two rotating surfaces, where h represents the height coordinate. This inner rotating surface is formed by the complete revolution of the agitator and is characterized by the distance r from the axis of rotation to the outer contour of the agitator. R (h). The stirring mechanism includes all components attached to it. A planar cross-section at any point h on the rotating surface perpendicular to the axis of rotation forms a circular surface. The perimeter of the cross-section is calculated using the following formula:

[0056] uR (h)=2πr R (h)

[0057] The rotating outer surface is formed by rotating the reactor's inner contour around the axis of rotation. It is measured using a distance r. B (h) describes the reactor. The inner contour of the reactor includes all components attached to it. The perimeter of any section of the outer surface of rotation perpendicular to the axis of rotation is calculated as follows:

[0058] u B (h)=2πr B (h)

[0059] The tight gap is defined by the following perimeter:

[0060]

[0061] Typically, a reactor may contain one or more agitators. The profile of each individual agitator forms a rotating surface throughout the rotation. These rotating surfaces may exist individually. They may preferably overlap each other. If the individual rotating surfaces or if the overlapping rotating surfaces are cut at any point perpendicular to one or more axes of rotation, this results in multiple figures or a single figure whose perimeter can be determined. If multiple figures are obtained, the total perimeter is determined by adding the individual perimeters.

[0062] Generally, the reactor can consist of one or more reactor components, each preferably rotationally symmetric and connected to each other. The entire reactor wall surrounds the shape. If this shape is cut at any point perpendicular to the axis of rotation of the stirring mechanism, the perimeter of the resulting shape is determinable. The tight clearance W(h) is calculated in a similar manner to that of a rotationally symmetric reactor.

[0063] The tightness can vary with h. In one embodiment of the stirrer according to the invention, when the tightness W(h) > 0.9 for at least half of all values ​​of h in the process zone, W(h) 50％ This is limited. In a preferred embodiment, W(h) 50％ W(h) > 0.95. In a particularly preferred embodiment, W(h) 50％ W(h) > 0.97. In a very particularly preferred embodiment, W(h) 50％ W(h) > 0.99. For a special case of this process, W(h) 50％ It is also possible for the value of ) to be greater than 1.

[0064] The goal is to minimize the dead zone of the bed that is not moved by the agitator. This allows the particles in the heated portion of the shell to remain in motion as efficiently as possible, and energy is transferred from the wall to the bed. This also prevents particle adhesion to the wall.

[0065] The process zone is the area in a reactor in which the stirred particle bed comes into contact with the gas phase, and it is further defined as the area in which chemical or physical processes, such as drying operations, gas-phase decomposition or condensation reactions, occur.

[0066] The gas phase consists of an inert gas and / or optionally at least one reactive component. This one or more reactive components can typically be introduced into the reactor either in a mixed form, separately, as a mixture with the inert gas component, or as a pure substance. Based on the partial pressure of the inert gas component as a proportion of the total pressure of the reactive component under standard conditions (according to DIN 1343), the reactive component preferably contains 0% to 99%, particularly preferably up to 50%, especially preferably up to 30%, and very particularly preferably up to 5% of the inert gas component. Examples of inert gases that can be used include hydrogen, helium, neon, argon, krypton, xenon, nitrogen, or carbon dioxide or mixtures thereof, such as, for example, forming gases. Argon or, particularly, nitrogen, is preferred.

[0067] The reactive components can react under selected conditions, such as heat treatment, and are preferably selected from the group consisting of...

[0068] - Hydrogen, oxygen, carbon dioxide, carbon monoxide, nitrous oxide, nitric oxide, nitrogen dioxide, sulfur dioxide

[0069] -water vapor

[0070] - Under the selected conditions, these are gaseous hydrides, such as SiH4, GeH4, SnH4, SbH4, GaH3, AsH3, BiH3, NH3, PH3, H2S, and H2Se.

[0071] -Oligomers or polymers of silanes, especially those with the general formula Si n H n+2 Straight-chain silanes, where n can be an integer ranging from 2 to 10, and also including the general formula -[SiH2]. n - cyclic silanes, where n can be an integer ranging from 3 to 10.

[0072] -Oligomers or polymers of germanane, especially those with the general formula Ge n H n+2 Straight-chain germananes, where n can include integers ranging from 2 to 10, and also including the general formula -[GeH2]. n - cyclic germananes, where n can be an integer ranging from 3 to 10.

[0073] - Halogen precursors such as Cl2, F2, Br2, chlorosilanes, phosgene, fluorinated phosgene, hydrogen chloride, hydrogen bromide, hydrogen fluoride, boron trichloride, boron trifluoride, chlorine dioxide, sulfur hexafluoride, sulfur tetrafluoride, sulfur hexachloride, sulfur tetrachloride, silicon tetrafluoride, trifluorosilanes

[0074] - Silicone precursors and precursors for silanization, such as silanols and silazanes

[0075] Examples of possible precursors for polymer coatings from the gas phase include p-xylene or its halogenated derivatives, acrylates, methacrylates, poly(tetrafluoroethylene) dispersions, styrene, vinylpyrrolidone, maleic anhydride, etc.

[0076] - Hydrocarbons, preferably selected from the group consisting of: aliphatic hydrocarbons having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, such as, for example, methane, ethane, propane, butane, pentane, isobutane, hexane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane; unsaturated hydrocarbons having 1 to 10 carbon atoms, such as, for example, ethylene, acetylene, propylene, methylacetylene, butene, butyne (1-butyne, 2-butyne), isoprene, butadiene, divinylbenzene, vinylacetylene, cyclohexadiene, cyclooctadiene; cyclic unsaturated hydrocarbons, such as, for example, cyclopropylene, cyclobutene, cyclopentene, cyclohexene, cyclohexadiene, cyclopentadiene, dicyclopentadiene or norbornene; aromatic hydrocarbons, such as, for example, benzene, toluene, p-, m-, o-xylene, benzene Ethylene (vinylbenzene), ethylbenzene, diphenylmethane, or naphthalene; other aromatic hydrocarbons, such as, for example, phenol, o-, m-, p-cresol, umbelliferone, nitrobenzene, chlorobenzene, pyridine, anthracene or phenanthrene, myrcene, geraniol, thioterpineol, norbornene, borneol, isoborneol, borneolane, camphor, limonene, terpinene, pinene, pinane, terpenes, phenol, aniline, anisole, furan, furfural, furfuryl alcohol, hydroxymethylfurfural, dihydroxymethylfuran, and mixed fractions containing a variety of such compounds, such as, for example, from natural gas condensate, petroleum distillate, or coke oven condensate, from mixed fractions of product streams from fluidized catalytic cracking (FCC), steam cracking, or Fischer-Tropsch synthesis units, or more generally from hydrocarbon streams from wood, natural gas, petroleum, and coal processing.

[0077] The particularly preferred reactive components are selected from the group consisting of hydrogen, oxygen, carbon dioxide, carbon monoxide, silane (SiH4), and germanane (GeH4), which may be used individually or as mixtures.

[0078] During the process of metering the gas phase into the reactor, the components of the reactive components may exist, for example, in gaseous, liquid, or sublimated solid form.

[0079] The reactive component is preferably gaseous, liquid, solid (e.g., sublimable), or a mixture of substances, optionally composed of substances in different states of matter.

[0080] In a variant of this method, the gas phase is fed directly into the particle bed in the reactor, for example from below, from the side, or via a special agitator.

[0081] In a preferred embodiment, temperature, pressure, pressure change or differential pressure measurements, and airflow measurements in the reactor are determined using established measuring instruments and methods. After standard calibration, different measuring instruments yield the same measurement results.

[0082] The process of treating particles in the gas phase is preferably analyzed and monitored to identify the end of the reaction and thus keep the reactor occupancy time as short as possible. Methods for observing the reaction process include, for example, temperature measurements to determine the reaction progress by varying the ratio of solid to gaseous reactor contents to determine exothermic or endothermic properties, and other methods capable of observing changes in the composition of the gas space during the reaction. In a preferred variant of this method, the composition of the gas phase is determined by gas chromatography and / or a thermal conductivity detector and / or an infrared spectroscopy and / or a Raman spectroscopy and / or a mass spectrometry. In a preferred embodiment, the hydrogen content is determined by a thermal conductivity detector and / or any chlorosilanes present are determined by gas chromatography or gas infrared spectroscopy.

[0083] In a further preferred variant of the method, the reactor / gas emission location is equipped with a technical solution for removing the generated condensable or sublimable byproducts or products.

[0084] In a preferred embodiment of the method, the metering operation is repeated multiple times, wherein the gas phase added in each case may be the same or different, and a mixture of two or more reactive components is also possible. In each case, the added gas phase may also be the same or different, or may consist of a mixture of different reactive components.

[0085] As reactors used in the context of this application, preferred reactor types are those selected from the group consisting of: digesters, tubular reactors, stirred bed reactors, stirred tank reactors, and autoclaves. Stirred reactors and autoclaves are particularly preferred, stirred reactors are especially preferred, and stirred tank reactors are very particularly preferred. These reactors can operate under both negative and positive pressure. Reactors used in the method according to the invention must at least be temperature-controllable. They may also be vacuum-resistant and pressure-resistant. They may be further equipped with devices for metering and venting gases, as well as devices for introducing and removing solids.

[0086] Temperature-controlled reactors are typically reactors that can be operated so that the internal temperature can be adjusted, for example, within a range of -40°C to 1500°C. Smaller temperature ranges are possible.

[0087] All the necessary process steps can be carried out in the reactor according to the invention, but other reactors with different designs can also be used for particle pretreatment and posttreatment.

[0088] The particles and the resulting particulate solid products can typically be present as a fixed bed or in a stirred form under stirring during the method. Stirring and mixing of the particles or the resulting products is preferred. However, the particles must be actively mixed during contact with the gas phase used. This allows, for example, uniform contact between all porous particles and the gas phase or a uniform temperature distribution in the bed to be achieved. The tumbling of the particles can be accomplished, for example, by stirring the internal components of the reactor or by moving the entire reactor around the stirrer.

[0089] The bed temperature of the particles used in the process zone of a reactor equipped with a close-gap stirrer is preferably in the range of 10°C to 2000°C, particularly preferably from 30°C to 1500°C, and most preferably from 100°C to 1000°C.

[0090] Another preferred configuration of the reactor is a stationary reactor with a moving stirring device for tumbling. The purpose of tumbling is to ensure that the porous solids are in contact with the gas phase as uniformly as possible. Therefore, preferred geometries are cylindrical reactors, conical reactors, spherical or polyhedral rotationally symmetric reactors, or combinations thereof. The movement of the stirring device is preferably rotational. Other forms of movement are also suitable. The stirring device is preferably driven via a stirrer shaft, wherein each stirrer shaft may have one or two or more stirring devices. Two or more stirrer shafts may be introduced into the reactor, and one or two or more stirring devices may be present on each shaft. The main reactor axis is preferably horizontal or vertically oriented. In a further preferred embodiment, the stirrer shafts are mounted horizontally or vertically in the reactor with any desired orientation. For vertically operating reactors, a configuration in which, for example, one or two or more stirring devices mix the bed material by rotational movement via the main stirrer shaft is preferred. A configuration in which two or more stirrer shafts extend in parallel is also possible. It is also possible in a configuration in which two or more stirrer shafts do not operate parallel to each other. Another configuration of the vertically operating reactor is characterized by the use of a conveying screw. The conveying screw preferably conveys the bed material at the center. A further design according to the invention is a conveying screw that rotates along the edge of the reactor. A further preferred configuration is a planetary agitator system or a helical agitator system. For horizontally operating reactors, a configuration is preferred in which, for example, one or two or more agitators mix the bed material by rotational motion via a main agitator shaft. Configurations in which two or more agitator shafts extend in parallel are also possible. Another preferred configuration is in which two or more agitator shafts do not operate parallel to each other. For vertically operating reactors, preferred agitators are those selected from the group comprising helical agitators, spiral mixers, anchor agitators, or general agitators, which convey the bed material axially or radially, or both axially and radially, and have a tight gap W according to the invention. In horizontally operating reactors, it is preferred that two or more agitators are present on one shaft. The configuration according to the invention for agitators in horizontally operating reactors is a plowshare, impeller, blade agitator, helical agitator, or general agitator, which conveys the bed material axially and radially and has a tight gap W according to the invention. This tight gap can be reduced by additional scrapers on the agitator. In addition to the moving agitator, the reactor may also have rigid internal components, such as baffles.

[0091] In principle, suitable materials for constructing reactors for carrying out the methods according to the invention include any material that exhibits the necessary mechanical strength and chemical resistance under the appropriate process conditions. Regarding chemical resistance, the reactor can be constructed from suitable solid materials and chemically inert (pressure-bearing) materials with special coatings or platings on the media-contact portions.

[0092] According to the present invention, these materials are selected from the group consisting of:

[0093] - Metallic materials for steel (according to DIN CEN ISO / TR 15608) correspond to material groups 1 to 11; metallic materials for nickel and nickel alloys correspond to groups 31 to 38; metallic materials for titanium and titanium alloys correspond to groups 51 to 54; metallic materials for zirconium and zirconium alloys correspond to groups 61 and 62; and metallic materials for cast iron correspond to groups 71 to 76.

[0094] -Oxide ceramic materials in single-material systems, such as, for example, alumina, magnesium oxide, zirconium oxide, titanium dioxide (capacitor materials), and multi-material systems, such as, for example, aluminum titanate (a mixture of alumina and titanium oxide), mullite (a mixture of alumina and silicon oxide), lead zirconate titanate (piezoelectric ceramics), or dispersion ceramics such as zirconium-reinforced alumina (ZTA - zirconium oxide-toughened alumina - Al2O3 / ZrO2),

[0095] - Non-oxide ceramics, such as, for example, carbides, examples of which are silicon carbide and boron carbide; nitrides, examples of which are silicon nitride, aluminum nitride, boron nitride and titanium nitride; borides and silicides; and mixtures thereof; and

[0096] - Composite materials belonging to the particulate composite materials group, such as, for example, sintered carbides, ceramic composites, concrete and polymer concrete, fiber composites such as, for example, glass fiber reinforced glass, metal matrix composites (MMC), fiber cement, carbon fiber reinforced silicon carbide, self-reinforcing thermoplastics, steel reinforced concrete, fiber reinforced concrete, fiber plastic composites such as, for example, carbon fiber reinforced plastics (CRP), glass fiber reinforced plastics (GRP) and aramid fiber reinforced plastics (ARP), fiber ceramic composites (ceramic matrix composites (CMC)), infiltrated composites such as, for example, metal matrix composites (MMC), dispersion reinforced aluminum alloys or dispersion hardened nickel-chromium superalloys, layered composites such as, for example, bimetals, titanium-graphite composites, composite plates and composite pipes, glass fiber reinforced aluminum and sandwich structures, and structural composites.

[0097] This method is applicable to manipulating all particles of Geldart C class. The following list is for illustrative purposes only and does not limit the scope of this application. The particles used can be porous or non-porous. The particles used in the method according to the invention are preferably selected from the group consisting of amorphous carbon in the form of hard carbon, soft carbon, mesophase carbon microspheres, natural or synthetic graphite, single-walled and multi-walled carbon nanotubes and graphene; oxides such as silicon dioxide, silica gel, alumina, silicon-aluminum mixed oxides, magnesium oxide, lead oxide, iron oxide, cobalt oxide, manganese oxide, titanium oxide and zirconium oxide; carbides such as silicon carbide and boron carbide; nitrides such as silicon nitride and boron nitride; halides such as aluminum chloride, titanium chloride, magnesium chloride; salts such as carbonates (e.g., CaCO3, MgCO3), sulfates (e.g., CaSO4, MgSO4), sulfides (e.g., Mo2S) and other ceramic materials, as can be described by the following component formulas:

[0098] Al a B b C c Mg d N e O f Si g Where 0 ≤ a, b, c, d, e, f, g ≤ 1, and at least two coefficients a to g > 0 and a*3 + b*3 + c*4 + d*2 + g*4 ≥ e*3 + f*2.

[0099] Ceramic materials can be, for example, binary, ternary, quaternary, pentagonal, hexavalent, or heptagonal compounds. Preferred ceramic materials have the following compositional formulas:

[0100] Non-stoichiometric boron nitride (BN) z Where z = 0.2 to 1,

[0101] Non-stoichiometric carbonitrides CN z Where z = 0.1 to 4 / 3,

[0102] Boron carbonitride B x CN z Where x = 0.1 to 20, and z = 0.1 to 20, where x*3 + 4 ≥ z*3.

[0103] Boron oxide (BN) z O r Where z = 0.1 to 1, and r = 0.1 to 1, where 3 ≥ r*2 + z*3.

[0104] Boron, carbon, nitrogen oxides B x CN z O r Where x = 0.1 to 2, z = 0.1 to 1, and r = 0.1 to 1, and x*3 + 4 ≥ r*2 + z*3,

[0105] silicon carbide Si x CO z Where x = 0.1 to 2 and z = 0.1 to 2, and x*4 + 4 ≥ z*2,

[0106] Silicon carbonitride (Si) x CN z Where x = 0.1 to 3 and z = 0.1 to 4, where x*4+4≥z*3,

[0107] Boron carbonitride Si w B x CN z Where w = 0.1 to 3, x = 0.1 to 2 and z = 0.1 to 4, and w*4 + x*3 + 4 ≥ z*3.

[0108] Si-boron-carbon oxide w B x CO z Where w = 0.10 to 3, x = 0.1 to 2 and z = 0.1 to 4, and w*4 + x*3 + 4 ≥ z*2.

[0109] silicon boron carbon nitride oxide Si v B w CN x O z Where v = 0.1 to 3, w = 0.1 to 2, x = 0.1 to 4, and z = 0.1 to 3, where v*4 + w*3 + 4 ≥ x*3 + z*2, and

[0110] Al (aluminum boron silicon carbon nitrogen oxides) u B v Si x CN w O z , where u = 0.1 to 2, v = 0.1 to 2, w = 0.1 to 4, x = 0.1 to 2 and z = 0.1 to 3, where u*3+v*3+x*4+4≥w*3+z*2.

[0111] Additional particles used in the method according to the invention may also be mixed oxides, such as titanates (e.g., barium titanate, lead titanate, strontium titanate, aluminum titanate, perovskite, and others) or spinels (e.g., magnesium oxide spinel, cobalt chromite, cobalt aluminate, and others) or tungstates.

[0112] Additional particles used in the method according to the invention may be a matrix having one or more catalytic substances, such as nickel, copper, silver, gold, platinum, palladium, or rhodium, as well as metal compounds such as metallocene. Examples of catalyst supports that can be used include activated carbon, magnesium silicate, alumina, or polymers or silica gel.

[0113] Additional particles used in the method according to the invention may also have organic properties, such as polymers like covalent organic frameworks (COF), porous aromatic frameworks (PAF), resins like resorcinol-formaldehyde resin, melamine-formaldehyde resin, aminophenol-formaldehyde resin, polymers like polystyrene, polyvinylpyridine or copolymers thereof, or organometallic properties, such as metal-organic frameworks like MIL-101(Cr).

[0114] Amorphous carbon, silicon dioxide, boron nitride, silicon carbide, and silicon nitride, or mixtures of these materials, are preferred for use as particles; amorphous carbon, boron nitride, and silicon dioxide are particularly preferred.

[0115] The volume-weighted particle size distribution can be determined according to ISO 13320 using a Mie model with a Horiba LA 950 measuring instrument (using ethanol as the dispersion medium for porous particles) based on static laser scattering.

[0116] The particles are preferably in various particle forms. Particles may exist, for example, in separate or aggregated forms. Particles are preferably non-aggregated, and even more preferably, do not aggregate. Aggregation generally means that during the production of porous particles, primary particles are initially formed and aggregated and / or the primary particles are connected to each other, for example, via covalent bonds, thus forming aggregates. Primary particles are typically separate particles. Aggregates or separate particles can form agglomerates. Agglomerates are loose accumulations of aggregates or primary particles connected to each other, for example, by van der Waals interactions or hydrogen bonds. Agglomerated aggregates can be easily broken back into aggregates by common kneading and dispersing methods. Agglomerates can be partially broken down into primary particles by this method, if any. The presence of particles in aggregate, agglomerate, or separate particle forms can be visualized using, for example, conventional scanning electron microscopy (SEM). In contrast, static light scattering methods used to determine the particle size distribution or particle size of matrix particles cannot distinguish between aggregates and agglomerates.

[0117] The particles can have any shape, such as flakes, flakes, spherical, or even needle-like, with flakes or spherical particles being preferred. The morphology can be characterized, for example, by sphericity ψ or sphericity S. According to Wadell's definition, sphericity ψ is the ratio of the surface area of ​​a sphere of equal volume to the actual surface area of ​​the bulk. In the case of a sphere, ψ is 1. According to this definition, particles used in the method according to the invention have a sphericity ψ that is preferably 0.3 to 1.0, particularly preferably 0.5 to 1.0, and most preferably 0.65 to 1.0.

[0118] Sphericity S is the ratio of the circumference of an equivalent circle having the same area A as the projection of a particle onto a surface to the measured circumference U of this projection. In the case of ideally spherical particles, S will have a value of 1. For particles used in the method of the present invention, S is based on the percentage of sphericity distribution. 10 To S 90 The sphericity S is preferably in the range of 0.5 to 1.0, and particularly preferably 0.65 to 1.0. The sphericity S is measured, for example, by referring to a photomicrograph of a single particle using an optical microscope, or, in the case of particles <10 μm, preferably by scanning electron microscopy using a graphical evaluation with image analysis software (such as ImageJ).

[0119] If porous particles are used, the porous particles preferably have a porosity of ≥0.2 cm. 3 / g, with a preferred value of ≥0.6cm 3 / g and the optimal value is ≥1.0cm 3 / g of gas accessible pore volume.

[0120] Porous particles can have pores of any diameter, typically ranging from macropores (above 50 nm), mesopores (2-50 nm), and micropores (below 2 nm). Porous particles can be used in any mixture of different pore types. Pore size distribution is determined according to DIN 66134 (Gas Adsorption) for mesopores and according to DIN 66135 (Horvath-Kawazoe) for micropores; pore size distribution in the macropore range is assessed by mercury porosity determination according to DIN ISO 15901-1.

[0121] The gas-inaccessible pore volume of porous particles can be determined using the following formula:

[0122] The pore volume inaccessible to gas = 1 / density of pure material - 1 / density of framework.

[0123] Pure material density is the theoretical density of porous particles, based on phase composition or the density of a pure substance (the density of a material as if it had no closed porosity). Pure material density data can be found by those skilled in the art, for example, in the National Institute of Standards and Technology's Ceramic Data Portal (NIST, https: / / srdata.nist.gov / CeramicDataPortal / scd). For example, the pure material density of silicon oxide is 2.203 g / cm³. 3 The density of pure boron nitride is 2.25 g / cm³. 3 The density of pure silicon nitride is 3.44 g / cm³. 3 The density of pure silicon carbide is 3.21 g / cm³. 3 Skeletal density is the actual density of porous particles (accessible to gas), as measured by a helium hydrometer.

[0124] The method according to the invention can be used for contacting all solids with gases according to the invention. The product can be a modified solid from the reactor and / or part of the exhaust gas. A modified solid refers to a solid that has undergone chemical or physical alteration. It can be, for example, oxidized, reduced, calcined, annealed, activated, passivated, coated, infiltrated, dried, cooled, or heated. The resulting product can be porous or non-porous.

[0125] Without limiting the scope of this application, examples of the solid products produced include: metal powders, metal oxides, mixed oxides, hydroxides, hydrates, silicon, silicon compounds, silicon microspheres, roasted ore, salts, sulfates, carbonates, chlorides, oxalates, pigments, silicates, aluminum silicates, carbon black, organic substances, or catalysts.

[0126] Typical applications of products made using this method include batteries, tire industry, activated carbon treatment, materials for data transmission and storage, fuel cells, catalysts, clothing, cosmetics, coating materials, solar energy industry, and silicon industry.

[0127] The products discharged from the reactor along with the gas flow under standard conditions can be gas or liquid.

[0128] If a solid is obtained as a product by the method according to the invention, the obtained material can have any shape, such as flakes, flakes, spheres or needles, wherein flakes or spherical particles are preferred.

[0129] According to Wadell's definition, sphericity ψ is the ratio of the surface area of ​​a sphere of equal volume to the actual surface area of ​​the solid. In the case of a sphere, ψ is 1.

[0130] Sphericity S is the ratio of the circumference of an equivalent circle having the same area A as the projection of a particle onto a surface to the measured circumference U of this projection. In the case of ideally spherical particles, S will have a value of 1. The sphericity S is measured, for example, by referring to a photomicrograph of a single particle, using an optical microscope, or, in the case of particles smaller than 10 μm, preferably using a scanning electron microscope, by graphical evaluation using image analysis software (such as ImageJ).

[0131] An example of the application of the method according to the invention is the coating of Geldart C-type particles. This process is based on chemical vapor deposition (CVD), in which gaseous reactive components chemically decompose on the surface of the particles and thus form a film on the particle surface. Solid coating is a fundamental process in many industries, including chemicals, pharmaceuticals, agriculture, cosmetics, electronics, and food. Coatings are used for a variety of purposes to control the release or dissolution of active ingredients, improve powder flowability, protect reactive substances susceptible to oxidation, light, air, or moisture, improve mechanical properties (e.g., abrasion resistance and compressibility), or enhance aesthetic appeal (e.g., texture, appearance, odor and masking, color).

[0132] Polymer coatings can be obtained using this method. In this case, gas-phase monomers react to form a pure solid film directly on the surface. Polymerization and coating are thus carried out in a single processing step. This makes it possible to form highly cross-linked coatings, which cannot be produced by other methods due to incompatible monomers. A known gap in the application of CVD methods is the modification of surfaces with polymers that have limited solubility, such as those used with poly(tetrafluoroethylene) (PTFE) and many other fluoropolymers, conductive polymers, and highly cross-linked organic networks.

[0133] As an undesirable side reaction in the CVD process, particle formation (homogeneous deposition) can also occur from the gas phase. Typically, homogeneous deposition occurs at the hottest points of the reactor and will be more pronounced in reactors with high temperature gradients.

[0134] However, these undesirable side reactions can be avoided if the particles are in constant motion, as is the case in the stirred bed reactor according to the invention. This motion results in high heat transfer, which minimizes the temperature gradient within the reactor. Furthermore, particle agglomeration on the reactor walls is suppressed.

[0135] Other examples of using the stirred bed reactor according to the invention may include any chemical reaction between Geldart C-type fine particles and the gas phase. Examples of such chemical reactions may include:

[0136] - Etching

[0137] -Carbonization and calcination

[0138] -Reduction or oxidation reaction

[0139] - Functionalization of solids, such as, for example, halogenation, alkylation, nitration, hydroformylation, silanization

[0140] - Gas-gas reactions over a stirred catalyst, such as, for example, producing hydrogen from water vapor on the surface of a metal oxide.

[0141] - Surface treatments such as activation, passivation, and cleaning

[0142] -Physical methods, such as drying, including supercritical drying and annealing.

[0143] - Gas-solid reactions with solid or gaseous products, such as, for example, heterogeneous catalytic chemical reactions. An example of such a reaction can also be the production of polyethylene via the Ziegler-Natta process.

[0144] In heterogeneous catalytic reaction systems, that is, when reactants from the gas phase react on the surface of a solid catalyst, in addition to the good mass and heat transfer between the particles and the surrounding gas phase, there is also very good macroscopic energy transfer between the particle bed and the reactor wall. The constant motion of the particles and the tumbling of the entire particle bed lead to high heat transfer, resulting in the avoidance of hot spots and only a weak temperature gradient throughout the bed.

[0145] Another example of the application of the method according to the invention in a stirred bed reactor is the production of core-shell structures from Geldart C-type particles, which can be used, for example, as separating agents in HPLC and UHPLC columns. Column delivery packed with core-shell particles is significantly more efficient than that packed with fully porous particles of the same diameter. These particulate structures can be advantageously produced using the method according to the invention.

[0146] The products generated can be analyzed using suitable established analytical methods, such as NMR (nuclear magnetic resonance), EA (elemental analysis), IR (infrared spectroscopy), Raman spectroscopy, X-ray diffraction, SEM (scanning electron microscopy), qualitative analysis, quantitative analysis, electrogravimetric analysis, conductivity analysis, potentiometric analysis, polarography, particle size determination, surface characterization, chromatography, mass spectrometry, density determination, nitrogen adsorption, thermogravimetric analysis, calorimetry, ICP emission spectroscopy, volume determination, spectrophotometry, and ion chromatography.

[0147] The following analytical methods and instruments were used for characterization:

[0148] Inorganic analysis / elemental analysis:

[0149] The C content reported in the examples was determined using a Leco CS230 analyzer; for the determination of O and optionally N or H content, a Leco TCH-600 analyzer was used. Qualitative and quantitative determinations of other reported elements were performed by ICP (Inductively Coupled Plasma) emission spectrometry (Optima 7300DV, Perkin Elmer). For this purpose, the samples were acid-digested (HF / HNO3) in a microwave (Microwave 3000, from Anton Paar). ICP-OES determinations were based on the German version of ISO 11885 "Water quality – Determination of selected elements by inductively coupled plasma emission spectrometry (ICP-OES) (ISO 11885:2007); EN ISO 11885:2009", which is used for the analysis of acidic aqueous solutions (e.g., acidified drinking water, wastewater and other water samples, and aqua regia extracts from soil and sediments).

[0150] Particle size determination:

[0151] Particle size distribution was determined in the context of this invention according to ISO 13320 using static laser scattering with a Horiba LA 950. In sample preparation, particular care must be taken when dispersing the particles in the measurement solution to ensure that the size of individual particles, not aggregates, is being measured. The particles were dispersed in ethanol for measurement. For this purpose, prior to measurement, if desired, the dispersion was sonicated at 250W for 4 minutes in a Hielscher UIS250V laboratory sonicator with LS24d5 ultrasonic electrodes.

[0152] BET surface area measurement:

[0153] The specific surface area of ​​the material was measured by the BET method (using nitrogen gas as per DIN ISO 9277:2003-05) using a Sorptomatic 199090 instrument (Porotec) or an SA-9603MP instrument (Horiba) with nitrogen gas adsorption.

[0154] Skeletal density:

[0155] Skeletal density, which is the density of a porous solid based solely on the volume of the pore space into which external gas can enter, is determined by the He specific gravity method according to DIN 66137-2.

[0156] Gas-accessible pore volume:

[0157] The Gurwitsch gas-accessible pore volume is determined by gas adsorption with nitrogen according to DIN 66134.

[0158] Transformation:

[0159] The conversion rate is calculated, for example, as the quotient of the amount of the converted starting material in moles relative to the amount of the starting material (reactant) used in moles. In these examples, it indicates how much of the SiH4 molecules used are converted to Si.

[0160]

[0161] Yield:

[0162] Yield is the quotient of the actual mass of the product obtained to the theoretically maximum possible mass of the product. Yield is expressed as a percentage (%) of mass.

[0163]

[0164] It is a measure of the loss of particles entrained by the airflow. Detailed Implementation

[0165] Example

[0166] The SiH4 with a mass of 4.0 was obtained from Linde GmbH.

[0167] In all embodiments, amorphous porous carbon is used as porous particles:

[0168] -Specific surface area = 1907m² 2 / g

[0169] - Pore volume = 0.96 cm³ 3 / g

[0170] -Median volume-weighted particle size D50 = 2.95 μm

[0171] - Particle density = 0.7 g / cm³ 3

[0172] - Cohesive, classified as Geldart class: C

[0173] Conversion rate calculation in the example:

[0174] The conversion rate is calculated as the quotient of the amount of starting material converted (in moles) relative to the amount of starting material (reactant) used (in moles). In these examples, it indicates how much of the SiH4 molecules used are converted to Si.

[0175]

[0176] Production calculation for the example:

[0177] Yield is the quotient of the actual mass of the product obtained to the theoretically maximum possible mass of the product. Yield is expressed as a percentage (%) of mass.

[0178]

[0179] It is a measure of the loss of particles entrained by the airflow.

[0180] When conducting experimental implementation examples, the following reactors are used:

[0181] The reactor used in all embodiments 1 to 5 according to the present invention comprises a reactor having an inner radius r B The reactor consists of a cylindrical lower section (beaker) with a diameter of 121.5 mm and a height h = 512 mm, a lid with multiple connections (e.g., for gas supply, gas discharge, temperature measurement, and pressure measurement), and a flat bottom. There is no internal material on the walls. The reactor volume V... B =24l. The perimeter of any cross-section of the rotating surface generated by the rotation of the internal reactor profile around the axis of rotation is calculated to be 763.4 mm. The agitator used has a radius r R A multi-threaded helical agitator with a diameter of 119.5 mm is used. The complete rotation of the helical agitator creates a rotating surface. The circumference of any section perpendicular to the axis of rotation of this rotating surface is 750.8 mm. A tight clearance of W = 0.98 is obtained from these two circumferences. The height of the helix corresponds to approximately 75% of the net height inside the reactor. The reactor is filled such that the height of the stirred particle bed is lower than the height of the helix. Therefore, more than 50% of the process zone is within the region of the agitator with a tight clearance of W = 0.98. The beaker is electrically heated using a jacketed heater. The temperature between the heater and the reactor is measured in principle. Gas is supplied to the lower half of the bed (125 mm above the reactor base) via two submerged pipes with an outer diameter of d = 6 mm, which directly introduce the gas into the moving bed.

[0182] The fluidized bed reactor used in Comparative Example 1 (not according to the invention) consists of a cylindrical section with an outer diameter of 160 mm and a height of 1200 mm. The cylindrical section comprises a bottom chamber and the fluidized bed reactor itself. These two sections are separated from each other by a permeable substrate. Following the cylindrical reactor section at the top is the reactor section, which has a cross-sectional area twice that of the cylindrical reactor section. At the top of the reactor, there is a cover with filter elements for gas exhaust. The reaction temperature is regulated by heating the reactor walls; the height of the heating zone is 80% of the cylindrical length from the permeable substrate. The process temperature is measured by the temperature between the heating jacket and the outer wall of the reactor. Heating is electric heating. The fluidizing gas is therefore preheated with a gas heater before flowing into the fluidized bed reactor. A directly controlled solenoid valve pulses the fluidized gas flow. The fluidization index is used as a measure of fluidized bed quality.

[0183] In the initial tests, the minimum fluidization rate was determined by measuring the pressure drop of the fluidized bed.

[0184] Definition of fluidization index: The fluidization index FI is defined as the fluidization index FI in a fluidized bed Δp WS,测量值 The measured pressure drop and the theoretical maximum pressure drop Δp WS,th The ratio is calculated using the following Equation 1:

[0185]

[0186] Ignoring gas density, from bed m S Mass, gravitational acceleration g, and reactor cross-sectional area A W The theoretically achievable maximum pressure drop, such as Δp, can be calculated. WS,th =m S ·g / A WS .

[0187] In the case of a fully fluidized bed, the fluidization index is used to be no greater than 1.

[0188] Fluidization Index Determination: The fluidization index is the ratio of the measured pressure drop to the theoretical maximum possible pressure drop. To determine the fluidization index, the pressure drop of the fluidized bed must be measured technically. The pressure drop is measured as the pressure difference between the bottom and top of the fluidized bed. The differential pressure gauge converts the pressure detected on the membrane into a digital value and displays the pressure difference. The pressure measurement lines must be configured such that they are positioned directly above the gas-permeable substrate and directly above the fluidized bed. Additionally, the weight of the introduced particle bed must be accurately measured to determine the fluidization index. See also [VDI- [VDI HeatAtlas],11th edition,section L3.2 und Druckverlust in Wirbelschichten [Types of Flow and Pressure Drop in Fluidized Beds], pp.1371-1382, Springer Verlag, Berlin Heidelberg, 2013].

[0189] Determination of Minimum Fluidization Velocity: The minimum fluidization velocity is the fluidizing gas velocity – based on the empty reactor cross-sectional area – of a particle bed transitioning from a fixed bed to a fluidized bed. The minimum fluidization velocity can be determined by simultaneously measuring the regulated fluidizing gas flow using a mass flow meter and simultaneously measuring the pressure drop of the fluidized bed using a digital differential pressure gauge. Given the reactor's cross-sectional area, the fluidizing gas velocity can be calculated from the measured fluidizing gas flow. The plotted distribution of pressure drop versus fluidizing gas velocity is called the fluidized bed characteristic curve. It should be noted that the fluidized bed characteristic curve is recorded starting with a high fluidizing gas velocity and gradually decreasing that velocity. In the case of pure fixed bed crossflow, the pressure drop increases linearly. The associated fluidization index FI is less than 1. For a fully developed fluidized bed, the measured pressure drop is constant. The associated fluidization index FI is equal to 1. The minimum fluidization state lies at the transition between two regions. The associated fluidizing gas velocity based on the empty reactor cross-sectional area is equal to the minimum fluidization velocity. If the transition from a fixed bed to a fluidized bed is characterized by a range, the intersection of the extrapolated fixed-bed characteristic curve and the extrapolated fluidized-bed characteristic curve is defined as the minimum fluidization point. See also [VDI- [VDI Heat Atlas],11th edition,section L3.2 und Druckverlust in Wirbelschichten [Types of Flow and Pressure Drop in Fluidized Beds], pp.1371-1382, Springer Verlag, Berlin Heidelberg, 2013].

[0190] In Comparative Example 2 (not according to the invention), an indirect-heating rotary kiln was used. This rotary kiln had a rotating tube made of quartz glass, which could rotate about its longitudinal axis, had a diameter of 20 cm, and a heatable volume of 30 L. The outer wall temperature of the quartz tube was used as the determination of the processing temperature. Heating was performed electrically and could be adjusted in three zones. For the silicon permeation reaction to be carried out, the rotating tube should be hermetically sealed.

[0191] Comparative Example 1 (not according to the invention): Production of silicon-containing materials in a fluidized bed reactor using a pulsed fluidized gas flow.

[0192] 500g of amorphous carbon was used as the porous starting material (specific surface area = 1907m²). 2 / g, pore volume = 0.96cm³ 3 / g, median volume-weighted particle size D 50 =2.95μm, particle density =0.7g / cm³ 3 Geldart C-type particles were introduced into the reactor.

[0193] The particle bed was fluidized with a nitrogen-based fluidizing gas, the volume of which ensured a minimum fluidization rate at least three times that determined in preliminary experiments. Simultaneously, a solenoid valve was used to induce gas flow oscillations, with a frequency of 3 Hz between the valve's open and closed positions. The temperature in the reactor was then increased to a setpoint of 430°C. Due to the temperature increase, the fluidizing gas flow was adapted to achieve a fluidization index >0.95.

[0194] When the set temperature of 430°C is reached, the fluidizing gas is replaced by a reaction gas containing 10 vol% SiH4. During and after the fluidizing gas switching, the gas flow is maintained in a pulsating manner, with a frequency of 3 Hz between the valve's open and closed positions. Furthermore, not only is the fluidization index FI = 0.98, but the flow rate of the fluidizing gas is also adjusted to ensure that the fluidization index is always greater than 0.95 due to the change in the density of the porous raw material during silicon deposition.

[0195] After a 2.6-hour reaction time, the fluidizing gas was switched back to a pulsed flow of nitrogen. The heating power was reduced. When the temperature reached 50°C, the fluidizing gas was switched to a fluidizing gas consisting of 5% oxygen by volume under nitrogen and maintained for 60 minutes to allow controlled reactions of any reactive groups present on the surface of the obtained product. The reactor was then cooled to room temperature.

[0196] After the operation was completed, 990 g of black solid was discharged from the reactor. The obtained silicon-containing material was introduced into a cylindrical container and homogenized in a rotary drum annular mixer. Agglomerates formed as a result of the fluidized bed process were removed by sieving. The reaction conditions used for production and the material properties of the silicon-carbon composite particles are summarized in Table 2.

[0197] Comparative Example 2 (not according to the invention): Production of silicon-containing materials in a rotating tubular reactor by a method not according to the invention.

[0198] 0.9 kg of the same porous carbon as in Comparative Example 1 (specific surface area = 1907 m²) was charged into a rotating tube reactor (internal volume 30 L). 2 / g, pore volume = 0.96cm³ 3 / g, median volume-weighted particle size D 50 =2.95μm, particle density =0.7g / cm³ 3 Geldart C-type particles). After inertization with nitrogen, the reactor was heated to 430°C. Upon reaching this reaction temperature, the reaction gas (10% SiH4 in N2, metered at a rate of 2.3 m³ / s) was introduced. 3The product was passed through the reactor for 8.5 hours, during which time the reactor was rotated at approximately 7 rpm. The reactor was then purged with an inert gas. Before removing the product from the reactor, it was cooled to room temperature under an inert gas atmosphere. The reaction conditions used for production, as well as the material properties of the silicon-carbon composite particles, are summarized in Table 2.

[0199] Examples 1-5 (according to the present invention): Silicon-containing materials were produced by means of the method according to the present invention using silane SiH4 as a silicon precursor under standard pressure (0.1 MPa) (the corresponding values ​​of parameter AD and the example numbers are summarized in Table 1).

[0200] 2.4 kg of the same porous carbon (specific surface area = 1907 m²) was compared with that in Comparative Examples 1 and 2. 2 / g, pore volume = 0.96cm³ 3 / g, median volume-weighted particle size D 50 =2.95μm, particle density =0.7g / cm³ 3 Geldart C-type particles were introduced into a reactor (24 L, 25 cm in diameter) according to the invention, which was equipped with a stirring mechanism. The reactor temperature was then adjusted to 350 °C for 240 minutes, and the reactor was inertized with nitrogen.

[0201] The reactor is then heated to 430°C. When the reaction temperature is reached, the reactant gas is passed through the reactor at a concentration A and a metering rate B for C hours. The gas phase is supplied to the reactor while the particle bed is turned over by a tight-gap stirring mechanism (spiral stirrer) according to the invention, such that the ratio of the turning time to the average residence time of the reactive components is D, and the motion of the bed can be described by the Froude number 3.

[0202] The silicon-containing material was then cooled to 70°C over 120 minutes. The reactor was then purged with nitrogen for 1 hour, with dilute air containing 5% oxygen by volume for 1 hour, with dilute air containing 10% oxygen by volume for 1 hour, with dilute air containing 15% oxygen by volume for 1 hour, and then purged with air for 1 hour. Finally, the product was removed from the reactor.

[0203] Table 1 shows the experimental parameters according to Examples 1 to 5 of the present invention.

[0204]

[0205] The reaction conditions used for production and the material properties of the silicon-carbon composite particles are summarized in Table 2 below.

[0206] Table 2

[0207]

[0208]

[0209] *Not based on this invention

[0210] Regardless of the reactor used, the same characteristic material properties can be obtained. However, the SiH4 conversion, product yield, and reaction time in the reactor system according to the present invention are improved compared to fluidized beds and rotary kilns.

Claims

1. A method for increasing particle size d 90 A method for producing products by contacting <20μm Geldart C-type particles with the gas phase in a stirred fixed bed. in, The particle treatment occurs in a process zone within the reactor as gas passes through, where a stirred particle bed comes into contact with the gas phase, and the particles are tumbled within the process zone by a close-gap agitator during contact with the gas phase. In Equation 1, the stirring mechanism has a tight gap. For half of all values ​​of h, the tight gap W(h) in the process zone is W(h) > 0.9, where u R (h) = the outer perimeter of the stirring mechanism in the cross section at height coordinate h, and u B (h) = the inner circumference of the reactor in the cross section at the height coordinate h.

2. The method according to claim 1, wherein, The process zone of the reactor is rotationally symmetrical. Wherein, in Equation 1, the stirring mechanism has a tight gap. in W(h) = the tight clearance of the stirring mechanism in a rotationally symmetric reactor, defined as the quotient of the perimeters of two plane sections perpendicular to the axes of rotation of the two rotating surfaces, where h represents the height coordinate. u R (h) = The perimeter of the inner circular cross-section calculated according to Equation 2 at multiple arbitrary points h on the surface of rotation perpendicular to the axis of rotation, through a planar cross-section. u R (h)=2πr R (h) (2) r R (h) = the distance from the axis of rotation to the outer contour of the stirring mechanism, wherein the stirring mechanism includes all components attached thereto. u B (h) = The circumference of the outer surface of the circular outer surface of revolution, calculated according to Equation 3, at any point h on the surface of revolution perpendicular to the axis of revolution, through a plane section. u B (h)=2πr B (h) (3) The circular rotating outer surface is formed by rotating the inner contour of the reactor around the axis of rotation. r B (h) = the distance from the inner contour of the reactor to the axis of rotation. Furthermore, for half of all values ​​of h, the tight gap W(h) in the process zone must be >0.

9.

3. The method according to claim 1 or 2, wherein, The contact between the particles and the gas phase occurs at pressures ranging from 0.08 MPa to 5 MPa.

4. The method according to claim 1 or 2, wherein, The bed temperature in the process zone of the reactor equipped with the close-gap agitator is in the range of 30°C to 1500°C.

5. The method according to claim 1 or 2, wherein, The method is carried out in two or more interconnected reactors.

6. The method according to claim 1, wherein, The chemical or physical process occurs in the process zone of the reactor.

7. The method according to claim 6, wherein, The chemical process is selected from coating the particle surface with a new functionalization, the reaction of the gas phase with the particles, and the reaction of the gas phase at the particles.

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