Graphitization furnace including ash outlet

Abstract

In a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet, a product outlet, and a channel 100 connecting the raw material inlet and the product outlet. The graphitization furnace further includes an ash outlet 110 in gas communication with the channel 100, the ash outlet 110 including an ash collection chamber 120, the ash collection chamber 120 including a hatch 160, and a high surface area body 130 removablely disposed within the ash collection chamber 120, and / or a cooling means 140.

Description

[Technical Field]

[0001] This invention relates to the field of graphitization furnaces. More specifically, this invention relates to a graphitization furnace including an ash collection chamber. [Background technology]

[0002] The most commonly used anode material in lithium-ion batteries is graphite. Graphite can be lithium-ionized to the state of LiC6, which correlates to a theoretical maximum capacity of 372 mAh / g.

[0003] Artificial graphite can be produced by heating carbonaceous starting materials (e.g., coke and / or pitch) to a temperature of approximately 3000°C under the exclusion of oxygen. Heating can be carried out in a batch furnace or a continuous furnace. In a continuous furnace, powdered or granular carbonaceous material is transported along a heated channel between the raw material inlet and the product outlet, and can be converted into graphite during transport.

[0004] However, carbonaceous starting materials may still contain impurities. At the high temperatures of graphitization, these impurities may evaporate or gaseously release from the carbonaceous material during graphitization, for example, as volatile elements, carbides, or oxides. The impurities and the resulting volatile substances may also be referred to as ash. To obtain high-quality graphite from the graphitization process, ash must be removed from the carbonaceous material and the reaction zone of the furnace. Additionally, ash must be removed from the furnace in a controlled manner to prevent its undesirable condensation on parts of the furnace (e.g., in flue ducts).

[0005] Removing ash from furnaces operating at temperatures exceeding 3000°C in a practical and energy-efficient manner is challenging. This disclosure aims to address the aforementioned problems in graphitization furnaces. [Overview of the Initiative] [Means for solving the problem]

[0006] In a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet, a product outlet, and a channel 100 connecting the raw material inlet and the product outlet. The graphitization furnace further includes an ash outlet 110 in gas communication with the channel 100, the ash outlet 110 including a hatch 160, a high surface area body 130 removablely disposed within an ash collection chamber 120, and / or a cooling means 140.

[0007] In some embodiments, the graphitization furnace can be a continuous graphitization furnace, and in particular, a vertical continuous graphitization furnace.

[0008] In some embodiments, the ash outlet can be located adjacent to the channel and can be in gas communication with the channel.

[0009] In some embodiments, the ash outlet may include a gas inlet, and in particular, the gas inlet may be configured to allow gas from the channel to enter the ash outlet.

[0010] In some embodiments, the gas inlet can be located at the upstream end of the ash outlet, and / or the gas outlet can be located at the downstream end of the ash outlet.

[0011] In some embodiments, the channel may include a channel heating zone, a channel high-temperature reaction zone, and a channel cooling zone, and the ash outlet is in gas communication with the channel high-temperature reaction zone.

[0012] In some embodiments, the graphitization furnace may include at least one gas injection port.

[0013] In some embodiments, the channel may be provided with at least one gas injection port connected to a purge gas pump and / or pressure regulator, the purge gas pump and / or pressure regulator being configured, among other things, to maintain a pressure above ambient pressure inside the graphitization furnace.

[0014] In some embodiments, at least one gas injection port can be connected to a heat exchanger configured to preheat the injected gas.

[0015] In some embodiments, the ash outlet can include a gas outlet.

[0016] In some embodiments, the high-surface-area body portion can be made of felt, and in particular, carbon felt or graphite felt.

[0017] In some embodiments, the high-surface-area main body can be at least partially enclosed within the cartridge.

[0018] In some embodiments, the ash outlet may include a cooling zone, more specifically, the cooling zone may be arranged to surround at least a portion of the removable high-surface-area main body, and / or the cooling zone may be arranged between the inlet of the ash collection chamber and the channel, and / or the cooling zone may be arranged between the ash collection chamber and the gas outlet.

[0019] In some embodiments, the cooling zone may include cooling means.

[0020] In some embodiments, the cooling means can be configured to cool at least 70% by weight, more specifically at least 80% by weight, and in particular at least 90% by weight of the volatilized ash to a temperature below its respective solidification / condensation temperature.

[0021] In some embodiments, the cooling means can be configured to cool the volatile matter / gas stream to a temperature below 2000 °C, more specifically, below 1800 °C, even more specifically, below 1700 °C, and especially below 1500 °C.

[0022] In some embodiments, the ash outlet can include the cooling means, and more specifically, the cooling means can be provided closer to the gas inlet than to the high surface area body.

[0023] In some embodiments, it can be particularly advantageous that the cooling means can be provided further away from the gas inlet than from the high surface area body.

[0024] In some embodiments, the cooling means extends along the entire ash collection chamber.

[0025] In some embodiments, the graphitization furnace can include an ash collection container.

[0026] In some embodiments, the cooling means can include a cold trap.

[0027] In some embodiments, the channel can be surrounded by an isolation structure, and the ash outlet can be disposed within the isolation structure.

[0028] In some embodiments, the channel can be gas permeable, and more specifically, the channel can include gas permeable graphite, and especially, the channel can include porous graphite having a gas permeability of at least 0.3 cm 2 / s (measured according to DIN 51935:2019-07).

[0029] In some embodiments, the isolation structure can be gas-impermeable, and more specifically, the isolation structure can contain gas-impermeable graphite, and in particular, the isolation structure may be 0.3 cm (measured according to DIN 51935:2019-07) 2 It is possible to include gas-impermeable graphite having a gas permeability of less than / s.

[0030] In some embodiments, the ash outlet may include means for gas communication between the ash outlet and the channel, and in particular, the means for gas communication may be a pipe that penetrates an isolation structure surrounding the channel.

[0031] In some embodiments, a gas-permeable material can be placed between the channel and the isolation structure, which is more specifically a particulate carbonaceous material, in particular pearled soot, particulate graphite, particulate coke, or carbon black.

[0032] In some embodiments, the furnace may include a second ash collection chamber in gas communication with the channel, the second ash collection chamber including a second hatch, a second high-surface-area body portion removablely disposed within the second ash collection chamber, and / or a second cooling means. The ash collection chamber and the second ash collection chamber may be arranged so that they can operate in parallel, and the furnace further includes one or more valve means for controlling the gas communication between each ash collection chamber and the channel.

[0033] In a second embodiment, the disclosure relates to a method for using a graphitization furnace described in any prior embodiment to prepare graphite from a carbonaceous material. [Brief explanation of the drawing]

[0034] [Figure 1]This figure shows a cross-section of a channel including a high-surface-area main body and an ash outlet section that includes a hatch. [Figure 2] This figure shows a cross-section of a channel including an ash outlet section that contains a cooling means and an ash collection container. [Figure 3] This figure shows a cross-section of a channel including an ash outlet section that contains a cooling rod. [Modes for carrying out the invention]

[0035] The following provides a detailed description of this disclosure. Terms or phrases used in the description and embodiments of this disclosure are not to be constrained to have only common language or dictionary meanings, but rather to have their ordinary technical meanings as established in the relevant art, unless specifically defined otherwise in the following description. The detailed description will refer to specific embodiments to better illustrate this disclosure, but it is understood that the presented disclosure is not limited to these specific embodiments.

[0036] The most commonly used anode material in lithium-ion batteries is graphite. Graphite can be lithium-ionized to the state of LiC6, which correlates to a theoretical maximum capacity of 372 mAh / g.

[0037] Artificial graphite can be produced by heating carbonaceous starting materials (e.g., coke and / or pitch) to a temperature of approximately 3000°C under the exclusion of oxygen. Heating can be carried out in a batch furnace or a continuous furnace. In a continuous furnace, powdered or granular carbonaceous material is transported along a heated channel between the raw material inlet and the product outlet, and can be converted into graphite during transport.

[0038] However, carbonaceous starting materials can still contain impurities. These impurities (also called ash) can release gases from the carbonaceous material during graphitization. For example, coke can contain up to 20% by weight of ash. To obtain high-quality graphite from the graphitization process, the ash must be removed from the carbonaceous material. Depending on the nature of the impurities, the impurities can evaporate at different typical temperature levels during the process of heating the starting material to its maximum temperature (up to temperatures exceeding 3000°C). Furthermore, the ash can partially or completely condense and / or react on the cooler parts of the graphitization furnace. For example, the ash can condense at the gas outlet (e.g., the flue), which can result in the gas outlet becoming clogged. Also, the condensed ash can react during condensation, forming carbide compounds with the carbon or graphite material in the furnace that is exposed to the ash vapor, for example. Clogged gas outlets can result in overpressure in the furnace, which may require the shutdown of the graphitization furnace. The formation of char can lead to the destruction of affected furnace parts.

[0039] Ash typically contains inorganic impurities. Under graphitization conditions, these inorganic impurities can either evaporate, decompose, or otherwise react into volatile species, or be converted in situ into volatile species (e.g., carbides, elemental vapors, etc.). They can also be actively converted into more volatile substances by adding a purge gas.

[0040] This disclosure aims to facilitate the removal of these volatile substances by generating a pressure difference within the furnace. The pressure difference is generated by providing a preferential deposition site for the volatile substances outside the main reaction zone of the furnace. The preferential deposition site generates a pressure difference, which drives the volatile substances away from their site of origin (i.e., the carbonaceous material experiencing graphitization).

[0041] It has been found that removable high-surface-area body sections can be used as an effective means to provide a preferred deposition site while preventing excessive heat energy loss from the graphitization furnace. Additionally, it has been found that cooling means can be used as a further effective means to provide a preferred deposition site, and can be used to solidify gaseous ash from the gas stream, again preventing excessive heat energy loss from the graphitization furnace.

[0042] These methods can also be used in combination.

[0043] Furthermore, the removal of volatile substances by differential pressure drive described above can be further facilitated by providing a gas stream to the carbonaceous material that drives the volatile substances toward preferential deposition sites, and / or by providing a vacuum that pulls the volatile substances toward preferential deposition sites.

[0044] Accordingly, in a first embodiment, the disclosure relates to a graphitization furnace including a raw material inlet, a product outlet, and a channel 100 connecting the raw material inlet and the product outlet. The graphitization furnace further includes an ash outlet 110 which is in gas communication with the channel 100, and the ash outlet 110 includes an ash collection chamber 120. The ash collection chamber 120 includes a hatch 160. Furthermore, the ash collection chamber 120 includes a high surface area body 130 which is removablely disposed within the ash collection chamber 120. Alternatively or additionally to the hatch 160 and the high surface area body 130, the ash collection chamber 120 includes a cooling means 140.

[0045] Figure 1 shows a schematic cross-section of an exemplary graphitization furnace according to a first embodiment. In some embodiments, as shown in Figure 1, the graphitization furnace is a vertical type. Carbonaceous material is fed into a channel 100 through a raw material inlet and converted to graphite as it passes through the channel 100. The graphite is then discharged through a product outlet. The graphitization furnace further includes an ash outlet 110. In some embodiments, as shown in Figure 1, the ash outlet 110 is located adjacent to (i.e., outside of) the channel 100 and is in gas communication with the channel 100. In some embodiments, for example, the ash outlet 110 and the channel 100 do not form an integral or single body or apparatus, and the ash outlet 110 includes means for gas communication between the ash outlet 110 and the channel 100. The means of gas communication can be provided in the form of a pipe penetrating the isolation structure 200 surrounding the channel 100, but other configurations are also possible (for example, as discussed later with respect to Figure 2).

[0046] The location where channel 100 is in gas communication with the ash outlet 110 is not particularly limited and can be freely selected, for example, depending on the temperature profile of channel 100. In some embodiments, channel 100 may include a channel heating zone, a channel high-temperature reaction zone, and a channel cooling zone. The heating zone may be characterized by an increase in the temperature of the carbonaceous material in the flow direction when the graphitization furnace is used. The channel high-temperature reaction zone may be characterized by a carbonaceous material having a temperature of at least 80% of the maximum temperature achievable in the graphitization furnace. The channel cooling zone may be characterized by a decrease in the temperature of the carbonaceous material in the flow direction when the graphitization furnace is used. It may be particularly advantageous that the ash outlet 110 is in gas communication with the channel high-temperature reaction zone of channel 100, because this may help minimize the accumulation of undesirable ash in other parts of the furnace.

[0047] As described above, the removal of volatile substances can be further facilitated by providing the carbonaceous material with a gas stream that drives the volatile substances toward a preferred deposition site (i.e., the ash outlet 110). Thus, in some embodiments, the graphitization furnace includes at least one gas injection port (not shown in Figure 1). The gas injection port can be configured to dispense an inert gas (e.g., helium or argon) and / or a purge gas (e.g., a gas containing halogens). It may be particularly advantageous that the gas injection port is located closer to the product outlet than the opening through which the ash outlet 110 is in gas communication with the channel 100. In such a spatial arrangement, the inert gas or purge gas injected into the channel 100 facilitates driving the volatile substances toward the ash outlet 110 and away from the product outlet, making it possible to provide a purer product with lower gas consumption. Furthermore, it may be particularly advantageous that the gas injection port is positioned at approximately the same level as, or substantially the same level as (relative to the raw material inlet and product outlet) as the opening in which the ash outlet 110 communicates with the channel 100, and advantageously, also on the opposite side of the channel 100. However, this is not strictly necessary, in particular when multiple gas injection ports arranged circumferentially around the channel 100 are used. Positioning the gas injection port at (approximately) the same level as the opening in which the ash outlet 110 communicates with the channel 100 may help minimize the gas travel distance within the channel 100, and thus maximize the effect of transporting volatilized ash toward the ash outlet 110. Thus, energy loss may be reduced by reducing the amount of purge gas or inert gas required.In some embodiments, the channel 100 may be provided with at least one gas injection port connected to a purge gas pump and / or pressure regulator, the purge gas pump and / or pressure regulator being configured, in particular, to maintain a pressure above ambient pressure within the graphitization furnace. In some embodiments, at least one gas injection port is further connected to a heat exchanger configured to preheat the injected gas. From an energy efficiency standpoint, it may be particularly advantageous that the heat exchanger is configured to draw heat from the gas leaving the channel 100 toward the ash outlet 110, or to draw heat from the channel cooling zone of the channel 100.

[0048] In some embodiments, the graphitization furnace can be a continuous graphitization furnace, and in particular, a vertical continuous graphitization furnace. Providing an ash outlet 110 in a continuous graphitization furnace can be particularly advantageous, because it can allow for the continuous removal of ash from the graphitization furnace, which otherwise might require frequent shutdowns of the oven to remove ash to prevent safety hazards.

[0049] Next, the ash outlet section 110 will be described in more detail.

[0050] The portion of the ash outlet 110 that connects to the channel 100 may be referred to as the gas inlet 210. In some embodiments, the gas inlet 210 may be configured to allow gas from the channel 100 to enter the ash outlet 110. In some embodiments, the gas inlet 210 may be located at the upstream end of the ash outlet 110, and / or the gas outlet 150 may be located at the downstream end of the ash outlet. The terms upstream and downstream refer to the direction of gas flow within the ash outlet 110. In some embodiments, as shown in Figure 1, the ash outlet 110 includes an ash collection chamber 120 and a high-surface-area body 130 that is removable therein. Due to its large surface area, the high-surface-area main body 130 can act as a preferred deposition site even in the absence of separate cooling means. However, as described in more detail below, it may be particularly advantageous to operate the high-surface-area main body 130 in combination with cooling means.

[0051] In some embodiments, the ash collection chamber 120 can be a section of the tubing of the ash outlet 110 and is configured to solidify the ash. Alternatively, the ash collection chamber 120 can be a section with a different diameter or distinct structure through which the gas stream is directed. Furthermore, in some embodiments, the ash outlet 110 can include a gas outlet 150, which can be used to process the remaining gas further downstream. A high-surface-area body 130 can be installed between the gas inlet 210 and the gas outlet 150, allowing the ash from the gas stream to solidify on the high-surface-area body 130 before the gas stream escapes through the gas outlet 150.

[0052] Furthermore, the ash collection chamber 120 includes a hatch 160. The hatch 160 can be opened to remove or replace the high-surface-area body 130. The specific form of the hatch is not particularly limited, as long as it allows access to the high-surface-area body 130. It can be as simple as a hatch door or more complex, such as an inert gas lock.

[0053] In some embodiments, the high-surface-area main body 130 can be a nonwoven material, such as felt, more specifically, carbonaceous felt, and in particular, graphite felt or carbon felt. Graphite felt and carbon felt can have a high surface area. Additionally, graphite felt and carbon felt can exhibit low thermal conductivity and high thermal resistance. Graphite felt can exhibit improved mechanical properties compared to non-graphite felt, which can ensure the structural integrity of the felt when removing it from the ash collection chamber 120. However, carbon felt can be less expensive and exhibit lower thermal conductivity compared to graphite felt. Additionally, carbon felt can be graphitized during ash collection. Since graphite felt and carbon felt exhibit high chemical resistance, they can be reused after the ash has been removed (chemically and / or physically).

[0054] In some embodiments, the high surface area body may include or be composed of particulate carbonaceous material, more specifically, particulate graphite, particulate coke, or pearl soot. In some embodiments, the high surface area body may include or be composed of carbon black.

[0055] In some embodiments, the high-surface-area body portion 130 can be a body portion including a plurality of lamellae or lips, in particular a plurality of lamellae or lips that form meandering paths for the gas stream. In some embodiments, the high-surface-area body portion 130 and the cooling means 140 can be the same structure, in particular the high-surface-area body portion 130 can be a first side of the heat exchanger, the cooling means 140 can be a second side of the heat exchanger, and the heat exchanger is removablely disposed within the ash outlet portion 110.

[0056] In some embodiments, the high-surface-area body portion 130 (which can be felt and / or particulate carbonaceous material) can be at least partially enclosed within the cartridge. The high-surface-area body portion (130) (in particular felt and / or particulate carbonaceous material) can be mechanically stabilized within the cartridge, making removal and cleaning more convenient. The cartridge can also retain pearl soot, carbon black, or particulate carbonaceous material in place.

[0057] In some embodiments, the ash outlet may include a cooling zone, more specifically, the cooling zone may be positioned to surround at least a portion of the removable high-surface-area main body, and / or the cooling zone may be positioned between the inlet of the ash collection chamber 120 and the gas inlet 210 of the ash outlet 110, and / or the cooling zone may be positioned between the ash collection chamber 120 and the gas outlet 150. The cooling zone may be cooled by ambient air. The cooling zone may assist in the condensation / precipitation of volatilized ash. In some embodiments, the cooling zone may include a cooling means 140. The cooling means 140 may be configured to allow heat dissipation into the environment, or may be configured to cool gas vapor (or a portion thereof) to a temperature below the solidification / condensation temperature of a considerable amount of ash by transferring heat into a circulating cooling medium (e.g., water or a second gas stream (e.g., in a cross-flow heat exchanger)). The cooling means 140 may include passive cooling means (e.g., surface expansion parts such as air fins). Alternatively or additionally, the cooling means 140 may include active means, such as air cooling or liquid cooling, and in particular, water cooling. The inlet of the ash collection chamber 120 does not necessarily have to be a distinct structure, and may, for example, be part of the ash collection chamber 120 closest to the channel 100 (where volatile ash begins to condense / settle), or may be part of the high surface area body 130 closest to the channel 100.

[0058] In some embodiments, the high surface area body portion 130 can have a thermal conductivity between approximately 0.01 Wm / K and approximately 0.4 Wm / K as measured at room temperature. In some embodiments, the high surface area body portion 130 has a thermal conductivity of 1.0 Wm at 2000°C. -1 K -1It is possible to have a lower thermal conductivity. A lower thermal conductivity can further reduce the loss of thermal energy from the graphitization furnace (particularly channel 100). Although thermal energy is inevitably removed from channel 100 by volatile substances / gas streams leaving channel 100, the high surface area body 130 exhibiting low thermal conductivity may be particularly beneficial in reducing thermal energy loss due to conduction and thermal radiation.

[0059] In some embodiments, the furnace may include (alternatively or additionally) a cooling means 140. The cooling means 140 may be a cooling sleeve at least partially positioned around the ash collection chamber 120. An example is shown in Figure 1 (in conjunction with the high surface area body 130). Note that the term cooling means 140 may refer to any furnace component configured to cool the gas vapor (or a portion thereof) to a temperature below the solidification / condensation temperature of a substantial amount of ash.

[0060] In some embodiments, it may be advantageous that the cooling means 140 is configured to cool at least 70% by weight, more specifically at least 80% by weight, and in particular at least 90% by weight of the volatile ash to a temperature below its respective solidification / condensation temperature. In some embodiments, it may be advantageous that the cooling means 140 is configured to cool the volatile substances / gas stream to a temperature below 2000°C, more specifically below 1800°C, even more specifically below 1700°C, and in particular below 1500°C. The above temperatures can lead to the condensation / precipitation of at least 70% by weight, more specifically at least 80% by weight, and in particular at least 90% by weight of the volatile ash. The above temperatures can allow for sufficient removal of the volatile ash and protect the furnace parts downstream of the ash collection chamber 120. As a result, the above temperatures can enable continuous operation, in particular in a continuous graphitization furnace. The remaining volatile ash can be removed, for example, by gas washing, further downstream of the gas outlet 150.

[0061] In some embodiments, the ash outlet 110 includes a cooling means 140 located closer to the gas inlet 210 than to the high-surface-area body 130. This can be useful for cooling volatile substances so as to improve the deposition of volatile substances on the high-surface-area body 130. For the same reasons, the cooling means 140 can (additionally or alternatively) at least partially surround the ash collection chamber 120, and, among other things, cool the gas while it is flowing through the high-surface-area body.

[0062] In some embodiments, it may be particularly advantageous that the cooling means 140 is located further away from the gas inlet 210 than the high surface area body 130. The ash can condense / settle on the high surface area body 130 without the assistance of the cooling means. For example, the ash collection chamber 120 can be located far enough away from the channel 100 that it has a temperature below the condensation temperature of a significant portion of the ash (e.g., lower than the condensation temperature of at least 70% by weight of the volatilized ash). The cooling means 140, located further away from the gas inlet 210 than the high surface area body 130, can assist in removing any remaining ash compounds with lower evaporation temperatures from the gas stream.

[0063] Furthermore, in some embodiments, the cooling means 140 extends along the entire ash collection chamber 120. The cooling means 140 can be configured to provide a gradually decreasing temperature profile between the gas inlet 210 and the gas outlet 150. A gradually decreasing temperature profile may be useful in preventing clogging of the high surface area body 130. In the case of a sudden temperature shift along the ash collection chamber, a large portion of the ash may solidify on the surface of the high surface area body 130 all at once. In the case of a gradual temperature shift, firstly, the ash compounds exhibiting the highest evaporation temperatures may solidify on the high surface area body 130 in the section closer to the gas inlet 210, followed by ash compounds with lower evaporation temperatures in the section closer to the gas outlet 150.

[0064] In some embodiments, the graphitization furnace can also be operated with an ash collection container 170, as depicted in Figure 2. Figure 2 shows a cross-section of an exemplary schematic graphitization furnace according to a first embodiment, including the ash collection container 170. The ash collection container 170 can be positioned between the gas inlet 210 and the gas outlet 150. Cooling means 140 (e.g., a cooling sleeve as depicted in Figure 2) can be positioned around the ash collection container 170. Additionally or alternatively, the cooling means 140 can be positioned at the inlet and / or outlet of the ash collection container 170. Thus, ash can be solidified and accumulated in the ash collection container 170. The ash collection container 170 may be removable to remove ash from it. The gas stream can be forced to enter the ash collection container 170, for example, through a downpipe or baffle, before leaving toward the gas outlet 150.

[0065] In some embodiments, the ash collection container 170 may contain particulate carbonaceous material (more specifically, particulate graphite or particulate coke). The particulate carbonaceous material may provide a precipitation surface for the ash and may be replaced to remove the ash from the ash collection container 170.

[0066] In some embodiments, the cooling means may include a cold trap. The cold trap may be removablely disposed within the ash collection chamber 120 or the ash outlet 110. Figure 3 shows a cross-section of an exemplary schematic graphitization furnace according to a first embodiment, including a cold trap. As depicted in Figure 3, the cold trap may be, for example, a cooling rod 190. The cooling rod 190 may contain or be composed of graphite. Graphite may exhibit high thermal resistance. Furthermore, depending on the grade, graphite may exhibit high thermal conductivity. The cold trap (e.g., the cooling rod 190) may be removed from the ash collection chamber 120 or the ash outlet 110, and ash may be removed from its surface. Removal of ash from the surface may be carried out, for example, by mechanical means (e.g., milling the ash from the rod) or by chemical means.

[0067] In some embodiments, and as depicted in Figure 1, for example, the channel 100 is surrounded by an isolation structure 200, and the ash outlet 110 can be disposed within the isolation structure 200. As depicted in Figure 2, the ash outlet 110 does not have to be directly connected to the channel 100; instead, a gap 180 can be disposed between the isolation structure 200 and the channel 100. The gap 180 can also include additional components. In some embodiments, a gas-permeable material can be disposed between the channel 100 and the isolation structure 200, more specifically, a particulate carbonaceous material, among others, pearl soot, particulate graphite, particulate coke, or carbon black. Pearl soot or carbon black can help thermally isolate the channel 100. The isolation structure 200 can include the isolation material. Additionally or alternatively, the isolation structure 200 can have a small interface with the channel 100 and / or the gas-permeable material. Due to the small interface, the rate of heat conduction from the channel 100 and / or the gas-permeable material to the isolation structure 200 may be low.

[0068] In some embodiments, the channel is gas-permeable, and more specifically, the channel may contain gas-permeable graphite.

[0069] In some embodiments, the isolation structure can be gas-impermeable, and more specifically, the isolation structure can contain gas-impermeable graphite.

[0070] In these and other instances, references to gas-permeable structures or materials include, among other things, at least 0.3 cm as measured according to DIN 51935:2019-07. 2It is possible to refer to a structure or material having a gas permeability of 0.3 cm² / s. In these and other cases, references to gas-impermeable structures or materials are, in particular, 0.3 cm² measured according to DIN 51935:2019-07. 2 It is possible to refer to a structure or material having a gas permeability lower than / s. Suitable structures or materials with the required gas (impermeability) are well known to those skilled in the art. For example, Sigrafine HLR, HLM, and HLS grades can be used as gas permeable materials, and Sigrafine HLX and isotropic graphite grades can be used as gas impermeable materials. All of these grades are available from SGL Carbon GmbH in Germany.

[0071] Therefore, the gas can leave the channel 100 through the gas-permeable graphite, enter the gap 180, and then enter the ash outlet 110.

[0072] In some embodiments, the graphitization furnace includes a second ash collection chamber that is in gas communication with channel 100. The second ash collection chamber may include a second hatch and a second high-surface-area body portion that is removablely disposed within the second ash collection chamber 120. As a result, the gas stream can be continuously removed from the graphitization furnace, for example, while the high-surface-area body portion 130 or the high-surface-area body portion is being replaced or cleaned. Additionally or alternatively, the second ash collection chamber may include a second cooling means. The ash collection chamber 120 and the second ash collection chamber may be arranged so that they can operate in parallel. The furnace may further include one or more valve means for controlling the gas communication between each ash collection chamber 120 and channel 100. As a result, the gas stream can be continuously removed from the graphitization furnace, for example, while the ash collection chamber 120 or the second ash collection chamber is being replaced or cleaned.

[0073] In a second aspect, the present disclosure relates to a method of using a graphitization furnace according to any preceding embodiment to prepare graphite from a carbonaceous raw material.

[0074] In some embodiments, the method is capable of producing graphite having a graphitization degree of at least about 46%, more specifically 69%, even more specifically at least about 80%, and particularly at least about 83%.

[0075] The crystallinity of graphite can be explained through its graphitization degree measured by X-ray diffraction (XRD). The crystalline carbon in graphite forms a plurality of honeycomb lattices. The distance between the plurality of honeycomb lattices is explained by the parameter "interplanar distance d 002 ". XRD can be used to measure the interplanar distance d 001 between the plurality of lattices. An interplanar distance d 002 of 0.3440 nm corresponds to the interplanar distance of turbostratic graphite, and an interplanar distance of 0.3354 nm corresponds to the interplanar distance in a perfect graphite crystal.

[0076] The interplanar distance can be used to calculate the graphitization degree by the following formula.

[0077] Graphitization degree = (0.3440 nm - d002) / (0.3440 nm - 0.3354 nm)

[0078] A higher graphitization degree can correspond to a higher maximum discharge capacity.

[0079] In some embodiments, the method is capable of producing graphite suitable for use as an anode material (particularly an anode material for a lithium battery).

[0080] In some embodiments, the method further includes the step of using graphite produced from operating a graphitization furnace (continuously) to produce an anode for a lithium battery.

[0081] Although the present invention is defined in the appended claims, it should be understood that the present invention may also be defined (alternatively) according to the following embodiments.

[0082] 1. A graphitization furnace, and the graphitization furnace is, The raw material inlet section; Product outlet section; A channel (100) connecting the raw material inlet and the product outlet; The ash outlet (110) is in communication with the channel (100) and the gas. Includes, The ash outlet section (110) includes an ash collection chamber (120), and the ash collection chamber (120) is a) A high-surface-area main body (130) that is removablely disposed within the hatch (160) and the ash collection chamber (120), and / or b) Cooling means (140) A graphitization furnace, including one.

[0083] 2. The graphitization furnace is a continuous graphitization furnace, and in particular a vertical continuous graphitization furnace, as described in Embodiment 1.

[0084] 3. The graphitization furnace according to any preceding embodiment, wherein the ash outlet (110) is provided adjacent to the channel (100) and is in gas communication with the channel (100).

[0085] 4. A graphitization furnace according to any preceding embodiment, wherein the channel (100) includes a channel heating zone, a channel high-temperature reaction zone, and a channel cooling zone, and the ash outlet (110) is in gas communication with the channel high-temperature reaction zone.

[0086] 5. The graphitization furnace is the graphitization furnace according to any preceding embodiment, comprising at least one gas injection port.

[0087] 6. The graphitizing furnace according to any preceding embodiment, wherein the channel (100) is provided with at least one gas injection port connected to a purge gas pump and / or pressure regulator, the purge gas pump and / or pressure regulator being configured, in particular, to maintain a pressure in the graphitizing furnace that is above ambient pressure.

[0088] 7. A graphitizing furnace according to embodiment 5 or 6, wherein at least one gas injection port is connected to a heat exchanger configured to preheat the injected gas.

[0089] 8. The graphitizing furnace according to any preceding embodiment, wherein the ash outlet (110) includes a gas outlet (150) and a gas inlet (210), the gas inlet (210) being configured in particular to allow gas from the channel (100) to enter the ash outlet (110).

[0090] 9. The graphitization furnace according to embodiment 8, wherein the gas inlet (210) is located at the upstream end of the ash outlet (210), and / or the gas outlet (150) is located at the downstream end of the ash outlet (210).

[0091] 10. The high surface area body (130) is felt, more specifically, the high surface area body (130) is carbon felt or graphite felt, in particular graphite felt; or The high surface area body contains or is composed of particulate carbonaceous material, more specifically, particulate graphite, particulate coke, pearl soot; or, A graphitization furnace according to any preceding embodiment, wherein the high surface area main body contains or is composed of carbon black.

[0092] 11. A graphitization furnace according to any preceding embodiment, wherein the high surface area main body (130) is at least partially enclosed within the cartridge.

[0093] 12. The graphitizing furnace according to any preceding embodiment, wherein the ash outlet (110) includes a cooling zone, more specifically, the cooling zone is arranged to surround at least a portion of a removable high-surface-area main body (130), and / or the cooling zone is arranged between the inlet of the ash collection chamber (120) and the channel (100), and / or the cooling zone is arranged between the ash collection chamber (120) and the gas outlet (150).

[0094] 13. The graphitization furnace according to embodiment 12, wherein the cooling zone includes a cooling means (140).

[0095] 14. A graphitization furnace according to any preceding embodiment, wherein the cooling means (140) is configured to cool at least 70% by weight, more specifically at least 80% by weight, and in particular at least 90% by weight of the volatilized ash to a temperature below its respective solidification / condensation temperature.

[0096] 15. A graphitization furnace according to any preceding embodiment, wherein the cooling means (140) is configured to cool the volatile substance / gas stream to a temperature below 2000°C, more specifically to a temperature below 1800°C, even more specifically to a temperature below 1700°C, and in particular to a temperature below 1500°C.

[0097] 16. The graphitizing furnace according to any preceding embodiment, wherein the ash outlet (110) includes a cooling means (140), and more specifically, the cooling means (140) is located closer to the gas inlet (210) than to the high surface area main body (130).

[0098] 17. A graphitization furnace according to any prior embodiment, wherein the cooling means (140) is located further away from the gas inlet (210) than the high surface area main body (130).

[0099] 18. A graphitization furnace according to any preceding embodiment, wherein the cooling means (140) extends along the entire ash collection chamber (120).

[0100] 19. The graphitization furnace is a graphitization furnace according to any prior embodiment, comprising an ash collection container (170).

[0101] 20. A graphitizing furnace according to any preceding embodiment, wherein the cooling means may include a cold trap and, in particular, a cooling rod (190).

[0102] 21. The graphitization furnace according to any preceding embodiment, wherein the channel (100) is surrounded by an isolation structure (200), and the ash outlet (110) is located within the isolation structure (200).

[0103] 22. Channel (100) is gas permeable, and more specifically, channel (100) contains gas permeable graphite, and in particular, channel (100) is at least 0.3 cm (measured according to DIN 51935:2019-07) 2 A graphitizing furnace according to any preceding embodiment, comprising porous graphite having a gas permeability of / s.

[0104] 23. The isolation structure (200) is gas-impermeable, and more specifically, the isolation structure (200) contains gas-impermeable graphite, and in particular, the isolation structure is 0.3 cm (measured according to DIN 51935:2019-07) 2 A graphitizing furnace according to any prior embodiment, comprising gas-impermeable graphite having a gas permeability less than / s.

[0105] 24. The graphitizing furnace according to any preceding embodiment, wherein the ash outlet (110) includes means for gas communication between the ash outlet (110) and the channel (100), and in particular the means for gas communication is a pipe penetrating an isolation structure (200) surrounding the channel (100).

[0106] 25. The graphitization furnace according to embodiment 21, wherein a gas-permeable material is disposed between the channel (100) and the isolation structure (200), which is more specifically a particulate carbonaceous material, in particular pearl soot, particulate graphite, particulate coke, or carbon black.

[0107] 26. The furnace includes a second ash collection chamber (120) which is in gas communication with a channel (100), and the second ash collection chamber (120) is A second hatch (160), and a second high-surface-area main body (130) removablely disposed within the second ash collection chamber (120), and / or Including a second cooling means (140), A graphitizing furnace according to any preceding embodiment, wherein an ash collection chamber (120) and a second ash collection chamber (120) are arranged so that they can operate in parallel, and the furnace further includes one or more valve means for controlling gas communication between each ash collection chamber (120) and a channel (100).

Claims

1. It is a graphitization furnace, The raw material inlet and Product outlet section, A channel (100) connecting the raw material inlet and the product outlet, The channel (100) and the ash outlet (110) which are in gas communication are included, The ash outlet section (110) includes an ash collection chamber (120), and the ash collection chamber (120) is (a) comprising a hatch (160) and a high surface area main body (130) removablely disposed within the ash collection chamber (120), and / or (b) A graphitization furnace including a cooling means (140).

2. The graphitizing furnace according to claim 1, wherein the graphitizing furnace is a continuous graphitizing furnace, and in particular a vertical continuous graphitizing furnace.

3. The graphitization furnace according to claim 1 or 2, wherein the ash outlet (110) is provided adjacent to the channel (100) and is in gas communication with the channel (100).

4. The graphitization furnace according to any one of claims 1 to 3, wherein the channel (100) includes a channel heating zone, a channel high-temperature reaction zone, and a channel cooling zone, and the ash outlet (110) is in gas communication with the channel high-temperature reaction zone.

5. The graphitizing furnace according to any one of claims 1 to 4, wherein the channel (100) is provided with at least one gas injection port connected to a purge gas pump and / or pressure regulator, the purge gas pump and / or pressure regulator being configured in particular to maintain a pressure in the graphitizing furnace that is higher than the ambient pressure.

6. The graphitizing furnace according to any one of claims 1 to 5, wherein the ash outlet (110) includes a gas outlet (150) and a gas inlet (210), and in particular the gas inlet (210) is configured to allow gas from the channel (100) to enter the ash outlet (110), more specifically the gas inlet (210) is located at the upstream end of the ash outlet (210), and / or the gas outlet (150) is located at the downstream end of the ash outlet (210).

7. The graphitizing furnace according to any one of claims 1 to 6, wherein the high surface area body portion (130) is felt, and more specifically, the high surface area body portion (130) is carbon felt or graphite felt, and in particular graphite felt.

8. The graphitization furnace according to any one of claims 1 to 7, wherein the ash outlet (110) includes a cooling zone, and more specifically, the cooling zone is arranged to surround at least a portion of the removable high-surface-area main body (130), and / or the cooling zone is arranged between the inlet of the ash collection chamber (120) and the channel (100), and / or the cooling zone is arranged between the ash collection chamber (120) and the gas outlet (150).

9. The graphitization furnace according to claim 8, wherein the cooling zone includes the cooling means (140), the cooling means (140) is configured to cool the volatile substance / gas stream to a temperature below 2000°C, more specifically to a temperature below 1800°C, even more specifically to a temperature below 1700°C, and in particular to a temperature below 1500°C.

10. The graphitization furnace according to any one of claims 1 to 9, wherein the cooling means (140) is provided further away from the gas inlet (210) than the high surface area main body (130), or extends along the entire ash collection chamber (120).

11. The graphitization furnace according to any one of claims 1 to 10, wherein the cooling means includes a cold trap, and in particular includes a cooling rod (190).

12. The channel (100) is gas permeable, and more specifically, the channel (100) contains gas permeable graphite, and in particular, the channel (100) has a thickness of at least 0.3 cm (measured according to DIN 51935:2019-07). ２ A graphitizing furnace according to any one of claims 1 to 11, comprising porous graphite having a gas permeability of / s.

13. The isolation structure (200) surrounding the channel (100) is gas-impermeable, and more specifically, the isolation structure (200) contains gas-impermeable graphite, and in particular, the isolation structure has a thickness of 0.3 cm (measured according to DIN 51935:2019-07). ２ A graphitizing furnace according to any one of claims 1 to 12, comprising gas-impermeable graphite having a gas permeability of less than / s.

14. The graphitizing furnace according to any one of claims 1 to 13, wherein the ash outlet (110) includes means for gas communication between the ash outlet (110) and the channel (100), and in particular, the means for gas communication is a pipe penetrating an isolation structure (200) surrounding the channel (100).

15. The graphitization furnace includes a second ash collection chamber (120) which is in gas communication with the channel (100), and the second ash collection chamber (120) is A second hatch (160) and a second high-surface-area main body (130) removablely disposed within the second ash collection chamber (120), and / or Including a second cooling means (140), The graphitizing furnace according to any one of claims 1 to 14, wherein the ash collection chamber (120) and the second ash collection chamber (120) are arranged to operate in parallel, and the graphitizing furnace further includes one or more valve means for controlling gas communication between the ash collection chamber (120) and the second ash collection chamber (120) and the channel (100).

Images