Cascade graphitization furnace

Abstract

The present disclosure relates to a graphitization furnace for continuously graphitizing particulate carbonaceous material, comprising: a raw material inlet and a product outlet; a plurality of sequentially arranged passage areas located between the raw material inlet and the product outlet, each of which passage areas is provided with a conveyor screw for transporting carbonaceous material through the passage areas; and at least one transition area located between two passage areas from the plurality of sequentially arranged passage areas and configured to enable the transport of carbonaceous material between the two passage areas.

Description

Technical Field

[0001] The present invention relates to the field of graphitization furnaces. More particularly, the present invention relates to a graphitization furnace having a cascaded arrangement of furnace passage areas.

Background Art

[0002] The most commonly commercially used anode material in lithium-ion batteries is graphite. Artificial graphite can be produced by heating carbonaceous starting materials such as coke and / or pitch to a temperature of about 3000 °C or higher under exclusion of oxygen. In practice, the heating can be carried out in batch or continuous furnaces. In a continuous furnace, a powdered or granular carbonaceous material is transported along a heated passage between a raw material inlet and a product outlet and can transition to graphite while being transported. The continuous graphitization process can be advantageous because it can produce graphite more efficiently. This is very important because the preparation of graphite is very energy-intensive. Nevertheless, the energy consumption of continuous graphitization furnaces is high. <00000C>

[0003] Also, the homogeneity and quality of the product are important. In initial experiments, the inventors of the present application found that achieving a certain uniform transport of the material and thus the homogeneity and quality of the product can be problematic in conventional vertically arranged tubular continuous furnaces due to cohesion and other issues. An improvement in this regard is desirable.

[0004] Furthermore, the carbonaceous starting material may contain impurities. At the high temperature of graphitization, these impurities can evaporate or evolve from the carbonaceous material during graphitization, for example, as volatile elements, carbides, or oxides. The impurities and the evolved volatile substances can also be referred to as ash. In order to obtain high-quality graphite from the graphitization process, the ash needs to be removed from the carbonaceous material and the reaction zone of the furnace. Removing ash from a furnace operating at a temperature of up to 3000 °C or higher in a practical, energy-efficient and cost-effective manner can be difficult.

Summary of the Invention

[0005] This disclosure aims to address one or more of the above-mentioned problems of graphitization furnaces. [Means for solving the problem]

[0006] In a first aspect, the disclosure relates to a graphitization furnace for the continuous graphitization of particulate carbonaceous material. The graphitization furnace comprises a raw material inlet and a product outlet. The graphitization furnace further comprises a plurality of sequentially arranged passage sections located between the raw material inlet and the product outlet. Each of the aforementioned passage sections is provided with a conveyor screw for transporting carbonaceous material through its respective passage section. The graphitization furnace further comprises at least one transition section located between two of the aforementioned sequentially arranged passage sections. The at least one transition section is configured to allow transport of carbonaceous material between the two aforementioned passage sections.

[0007] In some embodiments, at least one of a plurality of sequentially arranged passage areas is configured to transport material horizontally, substantially horizontally, or by an angular deviation greater than about 45° with respect to the axis pointing to the center of gravity of the Earth, more specifically between about 50° and about 90°, even more specifically between about 60° and about 90°, and particularly between about 75° and about 90°.

[0008] In some embodiments, a first passage area of ​​a plurality of sequentially arranged passage areas extends along a first axis, and a neighboring second passage area of ​​the plurality of sequentially arranged passage areas extends along a second axis, and a) a first angle in the horizontal plane between the first axis and the second axis is between about 15° and about 180°, more specifically between about 30° and about 180°, particularly between about 45° and about 180°, and / or, b) a second angle in the vertical plane between the first axis and the second axis is between about 15° and about 180°, more specifically between about 30° and about 180°, particularly between about 45° and about 180°, provided that the first angle and the second angle are not both 180°.

[0009] In some embodiments, the sequentially arranged passage areas include a first set and a second set of passage areas arranged substantially equilibrium with respect to each other, wherein the first set of passage areas is configured to transport carbonaceous material in substantially opposite directions to the second set of passage areas.

[0010] In some embodiments, at least one of the sequentially arranged passage areas is at least partially gas-impermeable.

[0011] In some embodiments, an internal (luminal side) or external (anti-luminal side) gas barrier layer is provided in at least one of a plurality of sequentially arranged passage areas.

[0012] In some embodiments, at least one of a plurality of sequentially arranged passage areas is provided with a conveyor screw containing graphite or carbon fiber reinforced carbon (CFRC), a conveyor screw made of graphite or carbon fiber reinforced carbon (CFRC), or a conveyor screw milled from graphite or carbon fiber reinforced carbon (CFRC).

[0013] In some embodiments, at least one of a plurality of sequentially arranged passage areas has a round or elliptical inner cross-section.

[0014] In some embodiments, at least one of a plurality of sequentially arranged passage areas consists of two or more passage area elements joined together to form a passage area, wherein a) one or more passage area elements are provided in a semicircular or U-shape in cross-sectional view, and / or b) one or more passage area elements are provided in a plate shape in cross-sectional view.

[0015] In some embodiments, at least one of a plurality of sequentially arranged passage areas contains graphite or carbon fiber reinforced carbon (CFRC), is made of graphite or carbon fiber reinforced carbon (CFRC), or is milled from graphite or carbon fiber reinforced carbon (CFRC).

[0016] In some embodiments, a conveyor screw with a flight that defines the transport volume in the passage is provided in at least one of a plurality of sequentially arranged passage sections, and the graphitization furnace is configured to operate such that the volume is filled with particulate carbonaceous material at a rate of less than about 50 vol%, more specifically between about 45 vol% and about 15 vol%, and particularly between about 35 vol% and about 25 vol%.

[0017] In some embodiments, a conveyor screw formed from multiple connected sections is provided in at least one of a plurality of sequentially arranged passage areas.

[0018] In some embodiments, at least one of a plurality of sequentially arranged passage areas is provided with a divided conveyor screw having a terminal that extends into or through a thermal insulation provided outside the passage area, the terminal being formed of a first material, and at least one section adjacent to the terminal being formed of a second material, the second material having a lower thermal conductivity than the first material.

[0019] In some embodiments, at least one transition area located between two passage areas is a vertical passage, a substantially vertical passage, or a passage provided with an angular deviation of less than about 60°, more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°, with respect to the axis pointing to the center of gravity of the Earth. In some embodiments, at least one transition area located between two passage areas is provided with an inclination of less than about 60°, more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°, with respect to the horizontal axis, i.e., the axis perpendicular to the axis pointing to the center of gravity of the Earth.

[0020] In some embodiments, the sequentially arranged multiple passage areas comprise at least three passage areas.

[0021] In some embodiments, a sequentially arranged set of passage areas comprises at least three passage areas, where the first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature, the second area is closer to the raw material inlet than the third area and is configured to operate at a second temperature, and the third area is configured to operate at a third temperature, with the first and third temperatures being lower than the second temperature. In some embodiments, it may be advantageous for the second temperature to be between about 2500°C and about 3300°C, more specifically between about 2600°C and about 3250°C, and particularly between about 2800°C and about 3200°C. In some embodiments, it may be advantageous for the first and third temperatures to be within the range of about 0°C to about 2500°C, more specifically between about 0°C and about 2200°C, and particularly between about 0°C and about 2000°C.

[0022] In some embodiments, the plurality of passage regions arranged in sequence comprises at least two passage regions, a first region being closer to the raw material inlet than a second region and configured to operate at a first temperature, the second region being configured to operate at a second temperature, the first temperature being lower than the second temperature, the conveyor screw of the first region being connected to a drive unit, in particular to an electric drive unit provided outside the thermal insulation of the first region, and the conveyor screw of the second region being mechanically connected to the conveyor screw of the first region by mechanical force transmission means such that the rotation of the conveyor screw of the first region drives the rotation of the conveyor screw of the second region, the mechanical force transmission means being provided inside or within the thermal insulation of the first region and / or the second region.

[0023] In some embodiments, one or more heating elements are provided outside one or more of the passage regions of the plurality of passage regions arranged in sequence.

[0024] In some embodiments, the plurality of passage regions arranged in sequence comprises at least two passage regions, a first region being closer to the raw material inlet than a second region and configured to operate at a first temperature, the second region being configured to operate at a second temperature, a transition region being arranged between the first region and the second region and provided as a vertical passage, as a substantially vertical passage, or as a passage with a deviation of an angle between about 0° and about 30° with respect to an axis pointing towards the earth's center of gravity, the transition region being configured to operate at a third temperature, the first temperature and the second temperature being lower than the third temperature.

[0025] In a second aspect, the invention is directed to a method of using a graphitization furnace as defined in any of the embodiments disclosed previously with respect to a first embodiment for preparing graphite from carbonaceous material.

Brief Description of the Drawings

[0026] [Figure 1] It is a diagram of an exemplary graphitization furnace according to the present disclosure. [Figure 1a] This is a diagram of a part of the graphitization furnace illustrated in this disclosure. [Figure 2] This is a cross-sectional view of an example passage section as illustrated in this disclosure. [Figure 3] This is a diagram of an illustrative conveyor screw of the present disclosure. [Figure 4] This figure shows the same example graphitization furnace as in Figure 1, but highlighting different features. [Modes for carrying out the invention]

[0027] A detailed description of this disclosure is provided hereafter. Terms or words used in this disclosure and in its manifestations should not be construed restrictively as merely general or dictionary meanings, but rather as having the ordinary technical meanings established in the relevant art, unless otherwise explicitly defined in the following description. While the detailed description refers to specific embodiments to better illustrate this disclosure, it should be understood that this disclosure is not limited to those specific embodiments.

[0028] In a first aspect, the disclosure relates to a graphitization furnace for the continuous graphitization of particulate carbonaceous material. The graphitization furnace comprises a raw material inlet and a product outlet. The graphitization furnace further comprises a plurality of sequentially arranged passage sections located between the raw material inlet and the product outlet. Each of the passage sections is provided with a conveyor screw for transporting carbonaceous material through its respective passage section. The graphitization furnace further comprises at least one transition section located between two passage sections from the aforementioned sequentially arranged passage sections. The at least one transition section is configured to allow transport of carbonaceous material between the two aforementioned passage sections.

[0029] Broadly speaking, a graphitization furnace is a technically well-known high-temperature furnace that operates at temperatures exceeding approximately 2800°C to transform carbonaceous starting materials, typically containing amorphous carbon such as coke and / or pitch, into graphite under the exclusion of oxygen.

[0030] The term “graphite” is well known, and for the purposes of this disclosure, its general technical meaning is attributed to it. More specifically, the term “graphite” can refer to a material having crystalline carbon in a hexagonal structure. Alternatively or additionally, the term “graphite” can refer to a material having at least about 60%, more specifically at least about 80%, and in particular at least about 83%, crystalline carbon in a hexagonal structure. Alternatively or additionally, the term “graphite” can refer to a material with a degree of graphitization of at least about 46%, more specifically 69%, and even more specifically at least about 80%, and in particular at least about 83%.

[0031] The degree of crystallinity of graphite can be described by its degree of graphitization, which can be measured by X-ray diffraction (XRD). In graphite, crystalline carbon forms a plurality of honeycomb lattices. The distance between these plurality of honeycomb lattices is represented by the parameter "interplanar spacing d002". XRD can be used to measure the interplanar spacing d002 between these plurality of lattices. An interplanar spacing d002 of 0.3440 nm corresponds to the interplanar spacing of randomly layered graphite, while an interplanar spacing of 0.3354 nm corresponds to the interplanar spacing in perfect graphite crystals.

[0032] The interplanar spacing can be used to calculate the degree of graphitization using the following formula. Graphitization degree = (0.3440nm - d002) / (0.3440nm - 0.3354nm) A higher degree of graphitization can correspond to a higher maximum discharge capacity in a battery.

[0033] According to this disclosure, graphitization is carried out in a continuous furnace, that is, in a furnace configured for the continuous or semi-continuous production of graphite. In a continuous furnace, carbonaceous raw materials are transported along a passage between a raw material inlet and a product outlet while being heated. In a continuous furnace, the flow of material can be truly continuous (at different rates in different sections of the furnace, optionally), but semi-continuous production is also possible, which includes keeping the reaction mixture still for a specific residence time. Furnaces configured for the continuous or semi-continuous production of graphite can eliminate the process of batch production of graphite in one or more crucibles.

[0034] The carbonaceous raw material to be graphitized can be in any particulate form, for example, in powder form or granular form, and more specifically in powder form.

[0035] The design of the graphitization furnace is further described below.

[0036] A graphitization furnace comprises a raw material inlet and a product outlet. The raw material inlet is not particularly limited and is generally part of the furnace through which the raw materials are fed into the passage that constitutes the beginning of the reaction chamber (i.e., the passage) in which the graphitization reaction takes place. The raw material inlet may optionally be equipped with, among many others, a feed meter, a drying station, a vacuum degassing station, a gas port for supplying an inert gas, or any combination thereof. The product outlet is not particularly limited and is generally part of the furnace through which the graphitized product is drawn out of the reaction chamber (i.e., the passage). For clarity, the process of cooling the graphitized material from the graphitization temperature to a lower temperature (typically around ambient temperature) suitable for further handling of the material is considered part of the graphitization reaction for this purpose and takes place within the reaction chamber (i.e., the passage) in which the graphitization reaction takes place. The product outlet is an opening for removing the prepared graphite from the passage, and further equipment such as a flush port may optionally be fitted to maintain an inert gas atmosphere within the reaction chamber (i.e., the passage).

[0037] The graphitization furnace further comprises a plurality of sequentially arranged passage sections located between the raw material inlet and the product outlet. Each passage section is provided with a conveyor screw for transporting carbonaceous material through its respective passage section. The graphitization furnace further comprises at least one transition section located between two passage sections from the aforementioned sequentially arranged passage sections. The at least one transition section is configured to allow transport of carbonaceous material between the two aforementioned passage sections.

[0038] These features will be further described with reference to Figure 1, which illustrates a graphitization furnace as described herein. Figure 1 shows a graphitization furnace (100) comprising a series of sequentially arranged passage sections, more specifically, eight passage sections (101a to 101h) located between a raw material inlet (102) and a product outlet (103). Each passage section is provided with a conveyor screw for transporting carbonaceous material through its respective passage section. In Figure 1, each of the eight passage sections (101a to 101h) is provided with a conveyor screw (104a to 104h) that actively transports carbonaceous material horizontally from the upper inlet end of the passage section to the lower outlet end of the passage section.

[0039] Furthermore, the graphitization furnace of this disclosure also comprises an overall passage and at least one transition area located between two of the sequentially arranged passage areas described above. In Figure 1, seven transition areas (105a to 105g) are arranged between eight horizontally oriented passage areas (101a to 101h). As shown in Figure 1, the transition area can connect two adjacent passage areas to each other, more specifically, the outlet opening of a first passage area can be connected to the inlet opening of a second passage area. At least one transition area must be configured to allow the transport of carbonaceous material between the two aforementioned passage areas. This means that the size and position of the transition area are determined in such a way that carbonaceous material can leave each first (upstream) passage area and enter each second (downstream) passage area. In Figure 1, the seven transition zones (105a to 105g) are positioned vertically below the outflow ends of their respective upstream passage zones, allowing carbonaceous material, actively transported to the exit of each passage zone by its respective conveyor screw, to proceed to the vertical transition zone with the assistance of gravity (e.g., by falling), and from there to the upper entrance ends of the respective downstream passage zones located below the transition zones.

[0040] The aforementioned design may have several advantages.

[0041] Firstly, compared to graphitization furnaces arranged vertically or horizontally, the above design is more compact and requires less space in the factory. More importantly, the more compact design can have a smaller relative surface area, allowing for more energy-efficient thermal insulation.

[0042] Furthermore, dividing the reactor's reaction passages into a cascaded arrangement of passage areas can facilitate reactor maintenance. For example, individual screw elements can be more easily recovered from the reactor passages because they are much shorter and easier to handle. Also, the screws can be replaced individually. This can be important considering that only a portion of the screws (in Figure 1) are exposed to the maximum graphitization temperature of 3200°C. At these high temperatures, wear may be increased compared to the screws on the lower temperature side. This reactor design allows for easier access to screws that are subject to increased wear, whereas a reactor utilizing a single reaction passage would require the recovery of a large area of ​​the screw (or alternatively, the dismantling of the reaction passage in the high-temperature region, which is also cumbersome) to access the high-temperature elements.

[0043] Furthermore, this furnace design can reduce the number of replacement parts. For example, if all individual aisle sections and conveyor screws are identical, as shown in Figure 1, only a relatively small number of replacement parts should be stocked, thus greatly simplifying and making furnace repairs more cost-effective.

[0044] Furthermore, dividing the reactor's reaction passages into a cascaded arrangement of passage areas allows for more selective application of heat, inert gases, reaction gases, etc., to specific areas of the reactor. It is also possible to provide a greater load in some less critical passage areas (to improve energy efficiency) and to reduce the load in those passage areas where volatile substances need to be removed from carbonaceous materials (for example, by providing a higher rotational speed to the screw). Such smaller loads increase the surface area relative to the bulk of the material, facilitating the removal of volatile substances. The cascaded arrangement also provides a simple way to selectively adjust the residence time of a material over a specific temperature range.

[0045] Many design variations of this broad concept are currently being considered.

[0046] The exact number of sequentially arranged passages is not particularly limited. In some embodiments, the sequentially arranged passage areas comprise at least three passage areas. In some embodiments, the sequentially arranged passage areas comprise from two to about twenty passage areas, more specifically from three to about sixteen passage areas, and particularly from four to about twelve passage areas.

[0047] The number of transition zones will depend on the number of passage zones included in a series of sequentially arranged passage zones and on further design specifications of the furnace. In particular, the number of transition zones may be less than, or even substantially less than, the number of passage zones. For example, directly connecting two passage zones of a series of sequentially arranged passage zones, operating one conveyor screw from the upstream side of the two connected passage zones, and operating the other conveyor screw from the downstream side of the two connected passage zones have been considered. An example of such a design is shown in Figure 1a. Figure 1a does not show a complete furnace, but only two passage zones that are directly connected and equipped with two conveyor screws. As in Figure 1, the transition zone that feeds material into the first upstream passage zone and the transition zone that receives material from the second downstream passage zone are indicated by arrows. The material fed into the first screw exits the first screw and is pushed into the second screw where the two passage zones are joined. Next, the material is transported through a second screw to a second transition zone. A feature of this design is that it reduces stress in individual screws (due to their shorter length compared to having a single long screw), thereby reducing the force / torque that needs to be applied by the drive unit. As this example shows, there is not necessarily a fixed numerical relationship between the number of passage zones and the number of transition zones.

[0048] In some embodiments, the furnace comprises one to about 19 transition zones, more specifically two to about 15, and in particular three to about 11.

[0049] In some embodiments, the number of passage areas included in a sequentially arranged set of passage areas is an integer N, and the number of transition areas is N-1.

[0050] In some embodiments, the passage areas and transition areas, which are located within a sequentially arranged set of passage areas, are arranged alternately. This means that one transition area is located between every two passage areas.

[0051] In some embodiments, a passage area included in a plurality of sequentially arranged passage areas and at least one transition area form a passage connecting the raw material inlet to the product outlet.

[0052] In some embodiments, the graphitization furnace, more specifically the passage connecting the raw material inlet and the product outlet, comprises a plurality of sequentially arranged passage sections and at least one transition section. However, it is also possible to integrate further features into the passage, which are also explored herein. For example, as detailed later, the aforementioned plurality of sequentially arranged passage sections and at least one transition section can be combined with an additional vertical furnace section. This can be advantageous, particularly when the vertical furnace section is located in the hottest reaction region, as wear can be reduced by avoiding the use of mechanical parts in the hottest region. For example, it is also possible to incorporate a passage section primarily for stirring or agitating the carbonaceous material to improve the homogeneity of the product, which is also covered herein.

[0053] In some embodiments, one or more of a series of sequentially arranged passage areas are configured to transport material horizontally or substantially horizontally. An example of a design in which the passage areas are configured to transport material horizontally is shown in Figure 1.

[0054] However, deviations, particularly inclination, have also been considered, as this feature can reduce the external dimensions of the furnace and thus improve energy efficiency, and can improve material transport, especially when the passages are oriented so that material is carried downwards. In some embodiments, one or more passage sections of sequentially arranged passage sections are configured to transport material in a non-horizontal manner, particularly on a downward inclination. Terms such as inclination and downward inclination are used interchangeably herein, technically retaining their usual meanings and generally referring to a downward slope.

[0055] In some embodiments, one or more passage areas are configured to transport material with a positive or negative angular deviation greater than about 45° with respect to the axis pointing to the Earth's center of gravity, more specifically between about 45° and about 90°, more specifically between about 50° and about 90°, even more specifically between about 60° and about 90°, and particularly between about 75° and about 90°, so that the transport of material carried within each passage area is assisted by gravity.

[0056] In some embodiments, one or more of a plurality of sequentially arranged passage areas have a central longitudinal axis that is oriented horizontally, substantially horizontally, or, in particular, inclined, with respect to the axis pointing to the center of gravity of the Earth, with a deviation of a positive or negative angle between about 45° and about 90°, more specifically between about 50° and about 90°, even more specifically between about 60° and about 90°, and particularly between about 75° and about 90°, with respect to the axis pointing to the center of gravity of the Earth, with respect to a deviation of a positive or negative angle.

[0057] In some embodiments, the graphitization furnace is configured with a linear cascaded arrangement of passage areas, in particular, all pairs of sequentially arranged passage areas (i.e., two sequentially arranged passage areas) connected by a transition area are configured such that one passage area of ​​the pair transports material in one direction, and the other passage area of ​​the pair transports material in opposite or substantially opposite directions. For example, one passage area of ​​the pair transports material from left to right, and the other passage area of ​​the pair transports material from right to right, preferably horizontally. In some embodiments, all pairs of sequentially arranged passage areas have a transition area positioned between them, configured to transport material in alternating directions, in particular, in opposite or substantially opposite directions. For example, in embodiments having three or more passage areas where a transition area is positioned between each sequentially arranged passage area, odd-numbered passage areas (e.g., 1st, 3rd, etc.) may be configured to transport carbonaceous material in one direction, and even-numbered passage areas (e.g., 2nd, and where applicable, 4th, 6th, etc.) may be configured to transport carbonaceous material in opposite directions.

[0058] In some embodiments, a sequentially arranged set of passage areas includes a first set and a second set of passage areas arranged substantially equilibrium with respect to each other, wherein the first set of passage areas is configured to transport carbonaceous material in substantially opposite directions to the second set of passage areas. The passage areas comprising the sets do not need to be arranged sequentially. An example of such a design is shown in Figure 1. In Figure 1, the first, third, fifth, and seventh passage areas transport material horizontally from left to right, while the second, fourth, sixth, and eighth passage areas transport material horizontally from right to left in the opposite direction. However, other arrangements have also been considered. For example, a cascaded arrangement in which the passage areas are arranged in a triangular, rectangular, or square configuration (from a top view projection) has been considered. Improvements to the design in Figure 1 have also been considered in which the passage areas are arranged in a staggered pattern (from a side view projection), where lower temperature sections requiring less effective insulation are grouped together, and higher temperature sections are isolated with more effective insulation.

[0059] In some embodiments, it may be advantageous, particularly for reasons of facilitating thermal insulation, that the furnace is not configured in a linear cascaded arrangement of passage areas, but rather in a non-linear cascaded arrangement of passage areas. Thus, in some embodiments, a first passage area of ​​a plurality of sequentially arranged passage areas extends along a first axis, and a) a first angle in the horizontal plane between the first and second axes is between about 15° and about 180°, more specifically between about 30° and about 180°, particularly between about 45° and about 180°, and / or, b) a second angle in the vertical plane between the first and second axes is between about 15° and about 180°, more specifically between about 30° and about 180°, particularly between about 45° and about 180°, provided that both the first and second angles are not 180°. For the purposes of this definition, it should be understood that the terms vertical and horizontal refer to two planes that are perpendicular to each other. The vertical plane can extend toward the Earth's center of gravity.

[0060] In some embodiments, one or more of the passage areas have a rounded inner cross-section, particularly an oval or circular inner cross-section. A rounded shape, particularly a circular cross-section, may be beneficial in ensuring the efficient and / or reliable transport of carbonaceous material by the conveyor screw. An oval cross-section may be even more beneficial in providing space around the conveyor screw to facilitate gas exchange in the passage area. In particular, if the passage area has an elliptical cross-section, this may be advantageous because the major axis of the ellipse is vertically aligned, which can further facilitate gas exchange by directing the gas upwards from the conveyor screw.

[0061] In some embodiments, at least one of a plurality of sequentially arranged passage areas consists of two or more passage area elements joined together to form each passage area. This can facilitate the fabrication of the passage areas, in particular when the passage areas are milled from a block of graphite or a similar material. The passage area elements can be joined by any suitable means, in particular by fastening means such as bolts, screws, or external fasteners, or by adhesive means including pitch or resin (which is later carbonized / graphitized), or a combination thereof.

[0062] In some embodiments, at least one of a plurality of sequentially arranged passage areas consists of two or more passage area elements joined together to form a passage area, where a) one or more passage area elements are provided in a semicircular or U-shape in cross-sectional view, and / or b) one or more passage area elements are provided in a plate shape in cross-sectional view. It should be understood that the term “plate shape” is given its conventional technical meaning and, in addition or alternatively, can refer to passage area elements having at least two planar surfaces.

[0063] In some embodiments, at least one passage area consists of two passage area elements with a semicircular cross-section or two passage area elements with a U-shaped cross-section, which are joined together to form the respective passage areas, forming passage areas with a circular cross-section and an oval cross-section, respectively.

[0064] In other embodiments, at least one passage area comprises one passage area element having a semicircular or U-shaped cross-section and one or more passage area elements having a plate-shaped cross-section. Examples of such passage shapes are shown in Figure 2, which shows cross-sections of two different passage area embodiments, each consisting of two or more passage area elements. More specifically, Figure 2 on the left shows a U-shaped passage area element combined with one plate-shaped passage area element on top of a U-shaped passage area element. Figure 2 on the right shows a semicircular passage area element combined with three plate-shaped passage area elements, two of the plate-shaped passage area elements positioned vertically on the semicircular passage area element, and one of the plate-shaped passage area elements positioned horizontally on the vertically positioned plate. The positioning of the conveyor screw (201) in the passage area is also shown. Such designs can be more cost-effective to produce because creating / milling curved shapes is substantially more expensive than creating plate-shaped elements. Furthermore, these designs can offer the same advantages as those previously considered for the elliptical cross-sectional shape.

[0065] Preferably, two sequentially arranged passage areas, which are directly connected to each other, that is, arranged sequentially without a transition area in between, have the same cross-sectional shape and dimensions.

[0066] In some embodiments, at least one passage area contains graphite or carbon fiber reinforced carbon (CFRC), consists of graphite or carbon fiber reinforced carbon (CFRC), or is milled from graphite or carbon fiber reinforced carbon (CFRC).

[0067] In some embodiments, at least one of a plurality of sequentially arranged passage areas is at least partially gas-impermeable. This may be beneficial in more selectively providing inert gas flows, reactive gas flows, and / or purge gas flows to specific areas of the furnace. Furthermore, this may be beneficial in preventing the condensation of volatile substances in other furnace components, such as heating equipment and insulating materials, located outside each passage area. In some embodiments, it may be advantageous for all of the sequentially arranged passage areas to be at least partially gas-impermeable. In this context, "at least partially" includes, in particular, the entire passage area. In embodiments where at least one of the sequentially arranged passage areas consists of two or more passage area elements joined together to form the passage area, at least one of those elements may be gas-impermeable.

[0068] In some embodiments, at least one transition zone is at least partially gas-impermeable. In some embodiments, it may be advantageous for all transition zones to be at least partially gas-impermeable. In this context, “at least partially” includes, in particular, the entire transition zone. However, in those embodiments, where at least one transition zone consists of two or more transition zone elements joined together to form the transition zone, at least one of those elements may be gas-impermeable.

[0069] In these and other examples, references to gas permeable materials mean, in particular, at least 0.3 cm, as measured according to DIN 51935:2019-07. 2 This refers to a substance with gas permeability of 0.3 cm² / s. In these and other examples, references to gas-impermeable substances refer specifically to substances with gas permeability of 0.3 cm² as measured according to DIN 51935:2019-07. 2This refers to a substance with gas permeability of less than 1 / s. Suitable substances with the required gas (impermeability) are well known to those skilled in the art. For example, grades of Sigrafine HLR, HLM, and HLS can be used as gas permeable substances, while grades of Sigrafine HLX and isotropic graphite can be used as gas impermeable substances. All of these grades are available from SGL Carbon GmbH, Germany.

[0070] In some embodiments, at least one of a plurality of sequentially arranged passage areas is formed at least partially from a first gas-permeable material, and at least one other passage area of ​​the plurality of sequentially arranged passage areas is formed at least partially from a second gas-permeable material, the gas permeability of the first and second materials being measured according to DIN 51935:2019-07, where the gas permeability of the first material is at least five times, more specifically at least eight times, and in particular at least ten times, that of the second material. In other words, the passage components of the furnace are made from a material with lower permeability than the other components of the passage. Both materials may be graphite or CFRC (different grades thereof). In this context, "at least partially" includes, in particular, the entire passage area. In embodiments in which at least one of a plurality of sequentially arranged passage areas consists of two or more passage area elements joined together to form the passage area, at least one of those elements may have a first required gas permeability, and at least one other of those elements may have a second required gas permeability.

[0071] In some embodiments, an internal (luminal side) or external (anti-luminal side) gas barrier layer is provided in at least one of a plurality of sequentially arranged passage regions. In some embodiments, an internal (luminal side) or external (anti-luminal side) gas barrier layer is provided in at least one transition region of a plurality of sequentially arranged passage regions. Gas barrier layers are well known in technique and include various carbide coatings / layers (SiC and TaC, depending on the temperature in each region), as well as carbonaceous coatings / layers, penetration or impregnation to seal pores in graphite, and, for example, 0.3 g / cm³ 3 More specifically, about 0.5 g / cm³ 3 Approximately 1.9 g / cm³ 3 During that period, especially around 0.7 g / cm³ 3 Approximately 1.9 g / cm³ 3 There are carbon-based films, such as graphite foil, with densities between them. The gas barrier layer is 0.3 cm, measured according to DIN 51935:2019-07. 2 The gas barrier layer may optionally have a gas permeability of less than 1 / s. The gas barrier layer may optionally have a gas permeability at least 5 times lower, more specifically at least 8 times lower, and especially at least 10 times lower, than the gas permeability of the bulk material in the passage area. Gas permeability may be measured according to DIN 51935:2019-07.

[0072] In the above example, when referring to at least one of several sequentially arranged aisle areas, or similar terms, it should be understood that this also refers in particular to each embodiment in which all or a numerical majority of the aisle areas of the sequentially arranged aisle areas are given their respective characteristics.

[0073] The design of a conveyor screw is not particularly limited, as long as the screw can transport carbonaceous material through the passage area. The available screw designs are well known in technique and, in principle, applicable in this disclosure. The shape of the screw flight may vary from section to section along the screw to accommodate various requirements (transport, mixing, wear resistance, etc.). However, from a maintenance standpoint, it may be advantageous for at least some screws or at least some screw sections to be identical. The length of the conveyor screw is also not particularly limited. In some embodiments, the screw extends throughout the entire passage area. However, it is also possible that the latter (i.e., downstream) portion of the passage area is not occupied by the screw. For example, only about 70% of the length of the passage area may be occupied by the screw. In the remainder of the passage area, the carbonaceous material is simply pushed forward by the subsequent material exiting the screw. This can reduce screw wear and equipment costs. In some embodiments, the remainder of the passage area may have a wide cross-section to facilitate the flow of material, and in particular, may have a conical or trapezoidal shape.

[0074] In some embodiments, at least one passage area is provided with a conveyor screw containing graphite or carbon fiber reinforced carbon (CFRC), a conveyor screw made of graphite or carbon fiber reinforced carbon (CFRC), or a conveyor screw milled from graphite or carbon fiber reinforced carbon (CFRC).

[0075] In some embodiments, the furnace is equipped with a first conveyor screw, and the graphitization furnace is configured to operate such that the first conveyor screw operates at less than about 50 vol% of its theoretical maximum transport volume, more specifically between about 45 vol% and about 15 vol%, and particularly between about 35 vol% and about 25 vol%. These parameters can be determined by predetermined calculations and / or experiments, for example, as considered in the following embodiments.

[0076] In some embodiments, at least one passage area is provided with a conveyor screw having flights that determine the transport volume in the passage, and the graphitization furnace is configured to operate such that the volume is filled with particulate carbonaceous material at a rate of less than about 50 vol%, more specifically between about 45 vol% and about 15 vol%, and particularly between about 35 vol% and about 25 vol%. In other words, the conveyor screw is only partially filled, which can reduce problems such as coagulation and insufficient mixing of the carbonaceous material during transport and can improve the gas release of volatile substances. Determining the degree of filling of the screw can be calculated periodically or measured experimentally, but is not particularly limited. Those skilled in the art can rely on calculations, for example, according to DIN 15262: 1983-01. Alternatively, the screw shown in Figure 3 will be described illustratively, and those skilled in the art can proceed as follows: Figure 3 shows a passage area (301) in which a conveyor screw (302) is provided. The screw has multiple flights, and the distance between peaks a1 and a2 represents a single complete flight. The corresponding passage sections a1 and a2 have an internal volume from which the volume occupied by a single flight itself can be removed. This creates the aforementioned transport volume of the flight in the passage section. Based on this volume, the degree of carbonaceous filling can be calculated. The degree of filling can be experimentally measured, for example, using a transparent model of the passage (e.g., transparent PVC piping) and a model of the screw. The measurement can be performed after achieving a steady-state flow, i.e., the same flow of material at the inlet and outlet.

[0077] In some embodiments, at least one passage area is provided with a conveyor screw formed from a plurality of joined sections. In some embodiments, at least one passage area is provided with a divided conveyor screw having a terminal that extends into or through a thermal insulation provided outside the passage area, the terminal being formed from a first material, and at least one section adjacent to the terminal being formed from a second material, the second material having a lower thermal conductivity than the first material.

[0078] In some embodiments, at least one transition area located between two passage areas is a vertical passage, a substantially vertical passage, or a passage provided with an angular deviation of less than about 60°, more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°, with respect to the axis pointing to the center of gravity of the Earth. In some embodiments, at least one transition area located between two passage areas is provided with an inclination of less than about 60°, more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°, with respect to the horizontal axis, i.e., the axis perpendicular to the axis pointing to the center of gravity of the Earth.

[0079] The transition zone can have two angular deviations with respect to the axis pointing to the Earth's center of mass, one in a plane and the other in a plane perpendicular to the first plane (hereinafter referred to as the "orthogonal angular deviation"). For clarity, it should be understood that this feature requires only an angular deviation in one direction, while the orthogonal angular deviation may, without particular limitation, be less than approximately 60° with respect to the axis pointing to the Earth's center of mass, more specifically between approximately 0° and approximately 60°, even more specifically between approximately 0° and approximately 30°, and especially between approximately 0° and approximately 15°.

[0080] In some embodiments, a sequentially arranged series of passage areas comprises at least three passage areas, where the first area is closer to the raw material inlet than the second area and configured to operate at a first temperature, the second area is closer to the raw material inlet than the third area and configured to operate at a second temperature, and the third area is configured to operate at a third temperature, with the first and third temperatures being lower than the second temperature. In particular, where the temperature (substantially) changes within the passage area, the aforementioned temperatures may refer together to the temperature at the inlet end, outlet end, or center of each area. Alternatively, the reference to temperature may mean that within a particular passage area, the temperature must meet a proposed temperature criterion at all locations within the passage area (e.g., above or below a certain temperature, or within a certain temperature range). In some embodiments, it may be advantageous for the second temperature to be between approximately 2500°C and approximately 3300°C, more specifically between approximately 2600°C and approximately 3250°C, and particularly between approximately 2800°C and approximately 3200°C. In some embodiments, it may be advantageous for the first and third temperatures to be within the range of approximately 0°C to approximately 2500°C, more specifically between approximately 0°C and approximately 2200°C, and particularly between approximately 0°C and approximately 2000°C. An illustrative temperature plan for the furnace described earlier in the context of Figure 1 is shown in Figure 4.

[0081] In some embodiments, a sequentially arranged set of passage areas comprises at least two passage areas, the first area being closer to the raw material inlet than the second area and configured to operate at a first temperature, the second area being configured to operate at a second temperature, the first temperature being lower than the second, the conveyor screws of the first area being connected to a drive unit, in particular to an electric drive unit located outside the thermal insulation of the first area, the conveyor screws of the second area being mechanically connected to the conveyor screws of the first area by mechanical force transmission means such that the rotation of the conveyor screws of the first area drives the rotation of the conveyor screws of the second area, the mechanical force transmission means being located inside or within the thermal insulation of the first and / or second areas. An example of such a design is shown in Figure 1, where an electric drive unit is shown in the lower left, and seven mechanical force transmission means (not indicated) are provided to connect eight conveyor screws.

[0082] In some embodiments, one or more heating elements are provided outside one or more of the sequentially arranged passage areas in one or more passage areas.

[0083] In some embodiments, a sequentially arranged set of passage areas comprises at least two passage areas, the first area being closer to the raw material inlet than the second area and configured to operate at a first temperature, the second area being configured to operate at a second temperature, and the transition area being located between the first and second areas and provided as a vertical passage, a substantially vertical passage, or a passage with an angular deviation of about 0° to about 30° with respect to the axis pointing to the Earth's center of gravity, more specifically between about 0° to about 15°, even more specifically between about 0° to about 10°, and particularly between about 0° to about 5°, the transition area being configured to operate at a third temperature, and the first and second temperatures being lower than the third temperature. Hereinafter, it should be noted that the transition area may have two angular deviations with respect to the axis pointing to the Earth's center of gravity, one in a plane and the other in a plane perpendicular to the first plane (hereinafter referred to as the "orthogonal angular deviation"). For clarity, it should be understood that this feature requires only an angular deviation in one direction, while orthogonal angular deviations may be between approximately 0° and 30°, more specifically between approximately 0° and 15°, even more specifically between approximately 0° and 10°, and especially between approximately 0° and 5°, with respect to the axis pointing to the Earth's center of gravity, although this is not particularly limited.

[0084] In some embodiments, the transition region is provided with one or more heating elements.

[0085] In some embodiments, it may be particularly advantageous that the shape of the transition area is conical toward the second passage area, wedge-shaped toward the second passage area, and / or has a cross-section that widens toward the second passage area.

[0086] It should be understood that all of the aforementioned embodiments of the first aspect of this disclosure can be freely combined, and that such combinations constitute part of this disclosure.

[0087] In a second aspect, the present invention is directed toward a method for preparing graphite from a carbonaceous material using a graphitization furnace as defined in any of the embodiments previously disclosed with respect to the first aspect.

[0088] The method includes, in particular, feeding a carbonaceous starting material into a graphitization furnace, converting the carbonaceous starting material into graphite in the furnace, and releasing the graphite from the furnace.

[0089] This disclosure also relates to the following list of embodiments.

[0090] 1. A graphitization furnace for continuously graphitizing particulate carbonaceous material, comprising: a raw material inlet and a product outlet; a plurality of sequentially arranged passage areas located between the raw material inlet and the product outlet, where each of the sequentially arranged passage areas is provided with a conveyor screw for transporting carbonaceous material through the passage area; and at least one transition area located between two passage areas from the sequentially arranged passage areas and configured to enable the transport of carbonaceous material between the two passage areas.

[0091] 2. A graphitization furnace of Embodiment 1, wherein at least one of a plurality of sequentially arranged passage sections is configured to transport material horizontally, substantially horizontally, or by a positive or negative angular deviation greater than about 45° with respect to an axis pointing to the center of gravity of the Earth, more specifically between about 50° and about 90°, even more specifically between about 60° and about 90°, and particularly between about 75° and about 90°.

[0092] 3. The first of several sequentially arranged passage areas extends along the first axis, and the second of the sequentially arranged passage areas, which is adjacent to it, extends along the second axis. a) The first angle in the horizontal plane between the first axis and the second axis is between approximately 15° and approximately 180°, more specifically between approximately 30° and approximately 180°, particularly between approximately 45° and approximately 180°, and / or b) The second angle in the perpendicular plane between the first axis and the second axis is between approximately 15° and approximately 180°, more specifically between approximately 30° and approximately 180°, and in particular between approximately 45° and approximately 180°. However, the graphitization furnace according to any prior embodiment is such that the first angle and the second angle are not both 180°.

[0093] 4. A graphitization furnace according to any prior embodiment, wherein a plurality of sequentially arranged passage areas include a first set and a second set of passage areas arranged substantially equilibrium with respect to each other, and the first set of passage areas is configured to transport carbonaceous material in substantially opposite directions to the second set of passage areas.

[0094] 5. A graphitization furnace according to any of the preceding embodiments, wherein at least one of a plurality of sequentially arranged passage areas is at least partially gas-impermeable.

[0095] 6. A graphitization furnace according to any of the preceding embodiments, wherein at least one of the sequentially arranged passage areas is provided with an internal (lumen-side) or external (anti-lumen-side) gas barrier layer.

[0096] 7. A graphitization furnace according to any of the preceding embodiments, wherein at least one of the sequentially arranged passage areas is provided with a conveyor screw containing graphite or carbon fiber reinforced carbon (CFRC), a conveyor screw made of graphite or carbon fiber reinforced carbon (CFRC), or a conveyor screw milled from graphite or carbon fiber reinforced carbon (CFRC).

[0097] 8. At least one of a plurality of sequentially arranged passage areas comprises two or more passage area elements that are joined together to form the passage area. a) One or more passage area elements are provided in a semicircular or U-shape in cross-sectional view, and / or b) A graphitizing furnace according to any of the preceding embodiments, wherein one or more passage area elements are provided in the form of plates in cross-sectional view.

[0098] 9. A graphitization furnace according to any of the preceding embodiments, wherein at least one of a plurality of sequentially arranged passage areas contains graphite or carbon fiber reinforced carbon (CFRC), consists of graphite or carbon fiber reinforced carbon (CFRC), or is milled from graphite or carbon fiber reinforced carbon (CFRC).

[0099] 10. A graphitizing furnace according to any of the preceding embodiments, wherein at least one of a plurality of sequentially arranged passage areas is provided with a conveyor screw having a flight that determines the transport volume in the passage, and the graphitizing furnace is configured to be operated such that the volume is filled with particulate carbonaceous material at a rate of less than about 50 vol%, more specifically between about 45 vol% and about 15 vol%, and particularly between about 35 vol% and about 25 vol%.

[0100] 11. A graphitization furnace according to any of the preceding embodiments, wherein a conveyor screw formed from a plurality of coupled screw sections is provided in at least one of a plurality of sequentially arranged passage sections.

[0101] 12. A graphitizing furnace according to any prior embodiment, wherein at least one of a plurality of sequentially arranged passage areas is provided with a divided conveyor screw having a terminal that extends into or through a thermal insulation provided outside the passage area, the terminal being formed of a first material, and at least one section adjacent to the terminal being formed of a second material, the second material having a lower thermal conductivity than the first material.

[0102] 13. A graphitization furnace according to any prior embodiment, wherein at least one transition zone located between two passage zones is a vertical passage, a substantially vertical passage, or a passage provided with an angular deviation of less than about 60° with respect to an axis pointing to the center of gravity of the Earth, and the angular deviation with respect to the axis pointing to the center of gravity of the Earth is more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°, or at least one transition zone located between two passage zones is provided with an inclination of less than about 60° with respect to a horizontal axis, i.e., an axis perpendicular to the axis pointing to the center of gravity of the Earth, more specifically between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15°.

[0103] 14. A graphitization furnace according to any of the preceding embodiments, wherein the sequentially arranged passage areas comprise at least three passage areas.

[0104] 15. The sequentially arranged multiple passage areas consist of at least three passage areas, The first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature. The second area is closer to the raw material inlet than the third area and is configured to operate at a second temperature. The third zone is configured to operate at a third temperature. A graphitization furnace according to any previous embodiment, wherein the first and third temperatures are lower than the second temperature.

[0105] 16. A graphitization furnace according to Embodiment 17, wherein the second temperature is between approximately 2500°C and approximately 3300°C, more specifically between approximately 2600°C and approximately 3250°C, and particularly between approximately 2800°C and approximately 3200°C.

[0106] 17. A graphitization furnace according to Embodiment 17 or Embodiment 18, wherein the first and third temperatures are within the range of about 0°C to about 2500°C, more specifically from about 0°C to about 2300°C, and particularly from about 0°C to about 2000°C.

[0107] 18. Multiple sequentially arranged passage areas comprise at least two passage areas, The first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature. The second area is configured to operate at a second temperature. The first temperature is lower than the second temperature. The conveyor screws of the first area are connected to a drive unit, and in particular to an electric drive unit located outside the thermal insulation of the first area. The conveyor screw in the second area is mechanically connected to the conveyor screw in the first area by a mechanical force transmission means such that the rotation of the conveyor screw in the first area drives the rotation of the conveyor screw in the second area. A graphitizing furnace according to any prior embodiment, wherein the mechanical force transmission means is provided inside or within the thermal insulation of the first and / or second zones.

[0108] 19. A graphitization furnace according to any of the preceding embodiments, wherein at least one of a plurality of sequentially arranged passage areas has a round or elliptical inner cross-section.

[0109] 20. A graphitization furnace according to any of the preceding embodiments, wherein one or more heating elements are provided externally in one or more of the sequentially arranged passage areas.

[0110] 21. Multiple sequentially arranged passage areas comprise at least two passage areas, The first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature. The second area is configured to operate at a second temperature. The transition zone is located between the first zone and the second zone and is provided as a vertical passage, a substantially vertical passage, or a passage with an angular deviation of about 0° to about 30° with respect to the axis pointing to the Earth's center of gravity. The transition zone is configured to operate at a third temperature. A graphitization furnace according to any previous embodiment, wherein the first and second temperatures are lower than the third temperature.

[0111] 22. A graphitization furnace according to Embodiment 21, wherein the shape of the transition zone is provided to be cone-shaped toward the second passage zone, wedge-shaped toward the second passage zone, and / or has a cross section that widens toward the second passage zone.

[0112] 23. A method for preparing graphite from carbonaceous material using a graphitization furnace according to any of the preceding embodiments. [Explanation of Symbols]

[0113] 100 graphitization furnaces 101a, 101b, 101c, 101d, 101e, 101f, 101g, 101h aisle area 102 Raw material inlet 103 Product outlet 104a, 104b, 104c, 104d, 104e, 104f, 104g, 104h Conveyor Screw 105a, 105b, 105c, 105d, 105e, 105f, 105g transition area 201 Conveyor Screw 301 Passage area 302 Conveyor Screw

Claims

1. A graphitization furnace for continuously graphitizing particulate carbonaceous material, Raw material inlet and product outlet, A plurality of sequentially arranged passage areas are located between the raw material inlet and the product outlet, Here, each of the sequentially arranged passage areas is provided with a conveyor screw for transporting the carbonaceous material through the passage area, From the aforementioned sequentially arranged plurality of passage areas, at least one transition area is located between two of the sequentially arranged passage areas and is configured to enable the transport of carbonaceous material between the two passage areas, A graphitization furnace equipped with the following features.

2. The graphitizing furnace according to claim 1, wherein at least one of the sequentially arranged plurality of passage areas is configured to transport material horizontally, substantially horizontally, or in a positive or negative angular deviation between about 45° and about 90° with respect to the axis pointing to the center of gravity of the Earth, more specifically between about 50° and about 90°, even more specifically between about 60° and about 90°, and particularly between about 75° and about 90° with respect to the axis pointing to the center of gravity of the Earth, in a positive or negative angular deviation.

3. The first passage area of ​​the sequentially arranged multiple passage areas extends along the first axis, and the second passage area adjacent to the sequentially arranged multiple passage areas extends along the second axis. a) The first angle in the horizontal plane between the first axis and the second axis is between about 15° and about 180°, more specifically between about 30° and about 180°, particularly between about 45° and about 180°, and / or b) The second angle in the perpendicular plane between the first axis and the second axis is between approximately 15° and approximately 180°, more specifically between approximately 30° and approximately 180°, and particularly between approximately 45° and approximately 180°. The graphitization furnace according to claim 1 or 2, wherein the first angle and the second angle are not both 180°.

4. The graphitization furnace according to any one of claims 1 to 3, wherein the at least one transition area is located between two sequentially arranged passage areas configured to transport material in substantially opposite directions.

5. The graphitization furnace according to any one of claims 1 to 4, wherein at least one of the sequentially arranged passage areas is at least partially gas-impermeable.

6. The graphitization furnace according to any one of claims 1 to 5, wherein at least one of the sequentially arranged passage areas is provided with an internal (lumen side) or external (anti-lumen side) gas barrier layer.

7. A graphitizing furnace according to any one of claims 1 to 6, wherein at least one of the sequentially arranged passage areas is provided with a conveyor screw containing graphite or carbon fiber reinforced carbon (CFRC), a conveyor screw made of graphite or carbon fiber reinforced carbon (CFRC), or a conveyor screw milled from graphite or carbon fiber reinforced carbon (CFRC).

8. The graphitization furnace according to any one of claims 1 to 7, wherein at least one of the sequentially arranged plurality of passage areas contains graphite or carbon fiber reinforced carbon (CFRC), is made of graphite or carbon fiber reinforced carbon (CFRC), or is milled from graphite or carbon fiber reinforced carbon (CFRC).

9. A graphitizing furnace according to any one of claims 1 to 8, wherein at least one of the sequentially arranged plurality of passage areas is provided with a conveyor screw having a flight that determines the transport volume in the passage, and the graphitizing furnace is configured to be operated so that the volume is filled with particulate carbonaceous material to less than about 50 vol%, more specifically between about 45 vol% and about 15 vol%, and particularly between about 35 vol% and about 25 vol%.

10. A graphitizing furnace according to any one of claims 1 to 9, wherein at least one of the sequentially arranged plurality of passage areas is provided with a divided conveyor screw having a terminal that extends into or through a thermal insulation provided outside the passage area, the terminal being formed of a first material, and at least one section adjacent to the terminal being formed of a second material, the second material having a lower thermal conductivity than the first material.

11. A graphitizing furnace according to any one of claims 1 to 10, wherein the at least one transition area located between two passage areas is a vertical passage, a substantially vertical passage, or a passage provided with an angular deviation of less than about 60° with respect to an axis pointing to the center of gravity of the Earth, and more specifically, an angular deviation of between about 0° and about 60°, more specifically between about 0° and about 30°, and particularly between about 0° and about 15° with respect to the axis pointing to the center of gravity of the Earth.

12. The aforementioned sequentially arranged multiple passage areas comprise at least three passage areas, The first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature. The second area is closer to the raw material inlet than the third area and is configured to operate at a second temperature. The third area is configured to operate at a third temperature, The graphitization furnace according to any one of claims 1 to 11, wherein the first temperature and the third temperature are lower than the second temperature.

13. The aforementioned sequentially arranged multiple passage areas comprise at least two passage areas, The first area is closer to the raw material inlet than the second area and is configured to operate at a first temperature. The second area is configured to operate at a second temperature. The transition area is located between the first area and the second area and is provided as a vertical passage, a substantially vertical passage, or a passage with an angular deviation of about 0° to about 30° with respect to the axis pointing to the Earth's center of gravity. The transition zone is configured to operate at a third temperature. The graphitization furnace according to any one of claims 1 to 12, wherein the first temperature and the second temperature are lower than the third temperature.

14. The graphitization furnace according to claim 13, wherein the shape of the transition area is provided with a cross section that is cone-shaped toward the second passage area, wedge-shaped toward the second passage area, and / or widens toward the second passage area.

15. A method for preparing graphite from a carbonaceous material using a graphitization furnace as defined in any one of claims 1 to 14.

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