A method and system for producing spinnable pitch

Abstract

The application provides a method and system for producing spinnable pitch, which comprises the following steps: (1) hydrogenating aromatic hydrocarbon-rich raw material to obtain light fraction, middle fraction and heavy fraction after separation; (2) performing first thermal polymerization treatment on the middle fraction to obtain hydrocarbon-containing stream A and pitch-containing stream A; (3) performing second thermal polymerization treatment on the pitch-containing stream A, the light fraction and the heavy fraction to obtain hydrocarbon-containing stream B and pitch-containing stream B; (4) performing separation on the pitch-containing stream B to obtain hydrocarbon-containing stream C and pitch-containing stream C; and (5) removing volatile components from the pitch-containing stream C to obtain spinnable pitch. The production method can increase the content of anisotropic structure in the spinnable pitch, and solve the problem of poor uniformity of molecular weight distribution of the spinnable pitch in the prior art while the softening point of the spinnable pitch is moderate.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology and relates to a method and system for producing optically anisotropic asphalt, and more particularly to a method and system for producing spinnable asphalt. Background Technology

[0002] Spinable pitch is the raw material for producing pitch-based carbon fiber. Properties such as optical anisotropy content, softening point, and degree of molecular polymerization are key factors affecting the spinning performance of spinable pitch. Production methods for spinable pitch include direct thermal polycondensation, latent mesophase method, pre-mesophase method, and catalytic modification method. Because direct thermal polycondensation does not require a catalyst, the process is simple, requires less equipment, and is easy to industrialize.

[0003] Patent CN112552946A discloses a method for preparing mesophase asphalt, in which raw material A is subjected to primary polymerization in an inert atmosphere at 380℃~420℃ to obtain material B; then material B is subjected to secondary polymerization in an inert atmosphere at 380℃~420℃ to obtain material C; and then material C is subjected to maturation reaction in an inert atmosphere at 320℃~360℃ to obtain mesophase asphalt.

[0004] Patent CN113773870A discloses a method for preparing mesophase asphalt. The method involves mixing medium-temperature coal tar and catalytic slurry in a specific ratio, extracting furfural, and then performing vacuum distillation to obtain a light component with a distillation range of 350℃–450℃ and a heavy component with a distillation range of 450℃–530℃. The heavy component is then reacted at a temperature of 390℃–450℃ and a pressure of 3MPa–5MPa to generate soft asphalt. The soft asphalt is then mixed with the light component and subjected to condensation polymerization at a temperature of 390℃–410℃ and a pressure of 3MPa–5MPa to obtain a reactant. Finally, the light component is removed from the reactant under vacuum to obtain mesophase asphalt.

[0005] Compared with other production methods, the raw materials of direct thermal polycondensation are mostly mixtures. Although the process is simple and easy to operate, the product properties are not easy to control uniformly, which is an urgent problem to be solved. Summary of the Invention

[0006] It is generally agreed in the art that a near 100% anisotropic microstructure content in spinnable pitch, with a softening point controlled below 300°C, is ideal. However, a high anisotropic microstructure content often results in a high softening point, and the proportion of highly polymerized macromolecules also increases, leading to reduced product uniformity. Therefore, preparing spinnable pitch with good uniformity while simultaneously achieving a suitable anisotropic microstructure content and softening point is a significant challenge in this field. This invention is formally proposed to address these problems.

[0007] To address the problems existing in the current production process of spinnable bitumen, the core of this invention is to provide a method and system for producing spinnable bitumen. The production method can increase the content of anisotropic microstructure in spinnable bitumen, and while having a moderate softening point, it solves the problem of poor uniformity of molecular weight distribution in existing spinnable bitumen.

[0008] I. This invention first provides a method for producing spinnable bitumen, comprising the following steps:

[0009] (1) Hydrogenation treatment is performed on aromatic-rich feedstocks. The liquid phase products of the hydrogenation reaction are separated to obtain light fraction, middle fraction and heavy fraction.

[0010] (2) The intermediate fraction from step (1) is subjected to a first thermal polymerization treatment. After the treatment is completed and separated, hydrocarbon-containing stream A and asphalt-containing stream A are obtained.

[0011] (3) The asphalt-containing stream A from step (2), the light fraction from step (1), and the heavy fraction from step (1) are subjected to a second thermal polymerization treatment. After the treatment is completed and separated, hydrocarbon-containing stream B and asphalt-containing stream B are obtained.

[0012] (4) After separating the asphalt-containing material stream B from step (3), hydrocarbon-containing material stream C and asphalt-containing material stream C are obtained;

[0013] (5) The hydrocarbon-containing stream C from step (4) is separated to obtain a light stream and a heavy stream;

[0014] (6) The asphalt-containing material stream C from step (4) is processed to remove the volatile components and obtain spinnable asphalt.

[0015] Furthermore, in the above method for producing spinnable pitch, the total aromatic content of the aromatic-rich raw material in step (1) is 40wt% to 95wt%, preferably 55wt% to 85wt%, the solid content is no more than 30ppm, preferably no more than 10ppm, and the quinoline insoluble content is no more than 1.0wt%, preferably no more than 0.5wt%. The aromatic-rich raw material can be selected from at least one of catalytic slurry, ethylene tar, coal tar pitch, etc., preferably catalytic slurry. The aromatic-rich raw material is preferably an aromatic-rich raw material after impurity removal treatment. Depending on the properties of the aromatic-rich raw material, the impurity removal treatment includes, but is not limited to, solidification treatment and removal of virgin quinoline insolubles treatment. Furthermore, the solidification treatment can be carried out by one or more of the following methods: filtration, centrifugal sedimentation, flocculation sedimentation, etc., preferably filtration, and more preferably inorganic membrane filtration. The removal of virgin quinoline insolubles treatment can be carried out by one or more of the following methods: hot filtration, solvent extraction, distillation treatment, etc. For those skilled in the art, the aforementioned deconsolidation treatment and removal of virgin quinoline insolubles treatment can be selected from any of the existing technologies in the art.

[0016] Furthermore, in the above-mentioned method for producing spinnable pitch, the hydrogenation treatment in step (1) involves hydrogenating the aromatic-rich feedstock in the presence of hydrogen and a hydrogenation catalyst. The hydrogenation treatment can employ at least one existing hydrogenation process, specifically at least one of the existing hydrogenation processes such as fixed-bed hydrogenation, suspended-bed hydrogenation, or fluidized-bed hydrogenation. The hydrogenation catalyst typically includes a support and an active metal component. The support is generally an inorganic refractory oxide such as alumina, and the active metal component is generally an oxide of Group VIB and / or Group VIII metals. More specifically, the hydrogenation catalyst can be self-made according to methods disclosed in the prior art, or it can be a commercially available catalyst in the field, such as the FZC and / or FH series hydrogenation catalysts developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0017] Furthermore, in the above method for producing spinnable pitch, the hydrogenation treatment in step (1) is carried out under the following conditions: the reaction temperature is 300℃~450℃, preferably 340℃~390℃; the pressure is 2MPa~15MPa, preferably 4MPa~8MPa; the hydrogen-to-oil volume ratio is 100~2500, preferably 800~1600; and the liquid hourly space velocity is 0.1h. -1 ~2.0h -1 Preferably 0.6h -1 ~1.5h -1 .

[0018] Furthermore, in the above-mentioned method for producing spinnable bitumen, the liquid phase product of the hydrogenation reaction in step (1) refers to the liquid phase material after the removal of non-condensable gases and light hydrocarbon components; the separation process after the hydrogenation reaction is completed usually includes gas-liquid separation and fractionation. The hydrogenation reaction product is first subjected to gas-liquid separation, and the separated liquid phase material (hydrogenation reaction liquid phase product) is further subjected to fractionation. Specifically, in this invention, the hydrogenation reaction product in step (1) is first subjected to gas-liquid separation, and the separated liquid phase material is further subjected to fractionation to obtain light fraction, middle fraction and heavy fraction. Fractionation preferably adopts vacuum distillation process, and the specific operating conditions can be adjusted according to actual needs. Those skilled in the art are familiar with how to determine the operating conditions.

[0019] Furthermore, in the above method for producing spinnable pitch, the sulfur content of the liquid phase product of the hydrogenation reaction in step (1) is not greater than 0.5 wt%, preferably not greater than 0.4 wt%, the 5% distillation temperature is 200℃~450℃, preferably 280℃~400℃, and the aromatic carbon content is 50mol%~85mol%, preferably 60mol%~80mol%.

[0020] Furthermore, in the above method for producing spinnable bitumen, the 5% distillation temperature of the intermediate fraction in step (1) is 300℃~500℃, preferably 400℃~480℃; the 95% distillation temperature is 470℃~580℃, preferably 500℃~560℃.

[0021] Furthermore, in the above method for producing spinnable bitumen, the first thermal polymerization treatment in step (2) is carried out under the following operating conditions:

[0022] The processing temperature is 350℃~500℃, preferably 400℃~480℃;

[0023] And / or, the processing pressure is 0.2 MPa to 5.0 MPa, preferably 0.5 MPa to 3.0 MPa;

[0024] And / or, the processing time is 2h to 20h, preferably 5h to 15h.

[0025] Furthermore, the first thermal polymerization treatment is carried out under stirring conditions, and the specific stirring rate can generally be controlled at 50 r / min to 800 r / min, preferably 60 r / min to 300 r / min.

[0026] Furthermore, in the above method for producing spinnable bitumen, the separation after the first thermal polymerization treatment in step (2) can be carried out using a vacuum distillation process. The specific operating conditions for vacuum distillation can be adjusted according to actual needs, and those skilled in the art are familiar with how to determine them. The product of the middle fraction after the first thermal polymerization treatment is separated into a hydrocarbon-containing stream A and a bitumen-containing stream A by vacuum distillation. The 5% distillation temperature of the bitumen-containing stream A in step (2) is 400℃~500℃, preferably 430℃~480℃; the softening point is 60℃~120℃; the toluene-insoluble content is not greater than 20wt%, preferably not greater than 12wt%; and the quinoline-insoluble content is not greater than 5wt%, preferably not greater than 0.5wt%.

[0027] Furthermore, in the above method for producing spinnable bitumen, the second thermal polymerization treatment in step (3) is carried out under the following operating conditions:

[0028] The processing temperature is 350℃~480℃, preferably 400℃~460℃.

[0029] And / or, the processing pressure is 0 MPa to 5.0 MPa, preferably 0.1 MPa to 1.5 MPa.

[0030] And / or, the processing time is 1 hour to 20 hours, preferably 2 hours to 10 hours.

[0031] Furthermore, the second thermal polymerization treatment is carried out under stirring conditions. The specific stirring rate can generally be controlled from 50 r / min to 800 r / min, preferably from 50 r / min to 200 r / min.

[0032] Furthermore, in the above method for producing spinnable bitumen, the separation after the second thermal polymerization treatment in step (3) can be carried out using a vacuum distillation process. The specific operating conditions for vacuum distillation can be adjusted according to actual needs, and those skilled in the art are familiar with how to determine them. The product after the second thermal polymerization treatment is separated into a hydrocarbon-containing stream B and a bitumen-containing stream B by vacuum distillation. The 5% distillation temperature of the bitumen-containing stream B in step (3) is 420℃~550℃, preferably 460℃~530℃. The softening point is 100℃~280℃, preferably 180℃~250℃.

[0033] Furthermore, in the above method for producing spinnable bitumen, the separation in step (4) can be carried out by sedimentation separation, specifically in a sedimentation tower. The sedimentation separation is carried out under the following operating conditions: temperature of 150℃~400℃, preferably 220℃~330℃; time of 1h~48h, preferably 6h~24h.

[0034] Furthermore, in the above method for producing spinnable bitumen, the content of optical anisotropic structure in the bitumen-containing material stream C in step (4) is greater than or equal to 60 vol%, preferably greater than or equal to 90 vol%.

[0035] Furthermore, in the above method for producing spinnable pitch, the content of optical anisotropic structure in the hydrocarbon-containing stream C in step (4) is less than or equal to 30 vol%, preferably less than or equal to 10 vol%.

[0036] Furthermore, in the above method for producing spinnable bitumen, the separation of the hydrocarbon-containing feed stream C from step (4) in step (5) to obtain a light feed stream and a heavy feed stream can be performed by centrifugal separation, preferably under the presence of an inert atmosphere. The inert atmosphere can be nitrogen and / or an inert gas, and the inert gas is at least one of helium, neon, argon, and krypton. Further, the operating conditions for centrifugal separation are as follows: temperature of 180℃~350℃, preferably 200℃~280℃, and rotation speed of 1000r / min~10000r / min, preferably 2000r / min~5000r / min.

[0037] Furthermore, in the above method for producing spinnable pitch, the content of optical anisotropic structure in the lightweight material obtained in step (5) is less than or equal to 5 vol%, preferably less than or equal to 1 vol%.

[0038] Furthermore, in the above method for producing spinnable pitch, the light material stream obtained in step (5) is recycled together with the liquid phase product of the hydrogenation reaction in step (1) and separated to obtain light fraction, middle fraction and heavy fraction.

[0039] Furthermore, in the above method for producing spinnable bitumen, the heavy material stream obtained in step (5) is recycled and separated together with the bitumen-containing material stream B in step (3) (sedimentation separation).

[0040] Furthermore, in the above method for producing spinnable bitumen, the treatment in step (6) is carried out under certain atmospheric conditions. The atmosphere is a gas that does not easily react with the bitumen-containing material C, and can be selected from at least one of water vapor, nitrogen, helium, and argon, preferably water vapor and / or nitrogen.

[0041] Furthermore, in the above method for producing spinnable bitumen, the processing conditions in step (6) are as follows: the temperature is 330℃~470℃, preferably 350℃~450℃, the time is 1~15h, preferably 2h~8h, and the atmosphere flow rate is 1~10L / (min·kg bitumen), preferably 1~5L / (min·kg bitumen).

[0042] Furthermore, in the above method for producing spinnable pitch, the volatile components removed in step (6) can be recycled and separated together with the liquid phase products of the hydrogenation reaction in step (1) to obtain light fraction, middle fraction and heavy fraction.

[0043] A second aspect of the present invention provides a system for producing spinnable pitch, the system comprising a hydrogenation unit, a primary thermal reaction unit, a secondary thermal reaction unit, a sedimentation separation unit, a centrifugal separation unit, and a devolatilization unit, wherein:

[0044] The hydrogenation unit includes a hydrogenation reactor and a hydrogenation separation system. The hydrogenation reactor is used to receive aromatic-rich feedstock and hydrogen. The hydrogenation reaction products are separated by the hydrogenation separation system to obtain light fraction, middle fraction and heavy fraction.

[0045] The primary thermal reaction unit includes a primary reactor and a primary separator. The primary reactor is used to receive the intermediate distillate separated from the hydrogenation unit and perform a first thermal polymerization treatment. The reaction products are separated by the primary separator to obtain a hydrocarbon-containing feed stream A and a bitumen-containing feed stream A.

[0046] The secondary thermal reaction unit includes a secondary reactor and a secondary separator. The secondary reactor is used to receive the asphalt-containing stream A from the primary thermal reaction unit, the light distillate and the heavy distillate separated from the hydrogenation unit, and perform a second thermal polymerization treatment. The reaction products are separated by the secondary separator to obtain a hydrocarbon-containing stream B and an asphalt-containing stream B.

[0047] A settling separation unit is used to receive asphalt-containing material stream B from the secondary thermal reaction unit, and separate it to obtain hydrocarbon-containing material stream C and asphalt-containing material stream C.

[0048] A centrifugal separation unit is used to receive the hydrocarbon-containing material stream C from the sedimentation separation unit, and after separation, obtain a light material stream and a heavy material stream;

[0049] The devolatilization unit receives the asphalt-containing material stream C from the settling and separation unit, and removes the volatile components in it under the action of devolatilization gas to obtain spinnable asphalt.

[0050] Furthermore, in the above-mentioned system for producing spinnable pitch, the hydrogenation separation system in the hydrogenation unit generally includes a gas-liquid separator and a fractionation tower. The hydrogenation reaction products first enter the gas-liquid separator and are separated to obtain a gas phase stream and a liquid phase stream. The liquid phase stream then enters the fractionation tower for further separation.

[0051] Furthermore, in the above-mentioned system for producing spinnable pitch, the light material separated by the centrifugal separation unit is connected to the feed inlet of the hydrogenation separation system in the hydrogenation unit via a pipeline, and is separated together with the hydrogenation reaction products to obtain light fraction, middle fraction and heavy fraction.

[0052] Furthermore, in the above-mentioned system for producing spinnable bitumen, the heavy material stream separated by the centrifugal separation unit is connected to the inlet of the sedimentation separation unit via a pipeline, and is circulated together with the bitumen-containing material stream B for separation.

[0053] Furthermore, in the above-mentioned system for producing spinnable bitumen, the hydrogenation reactor can be one or more of the existing hydrogenation reactors such as a fixed-bed hydrogenation reaction zone, a suspended-bed hydrogenation reactor, or a fluidized-bed hydrogenation reactor, with a fixed-bed hydrogenation reactor being preferred.

[0054] Furthermore, in the above-mentioned system for producing spinnable bitumen, both the primary reactor and the secondary reactor can be batch reactors, preferably batch reactors equipped with stirring equipment.

[0055] Furthermore, in the above-mentioned system for producing spinnable bitumen, both the primary separator and the secondary separator can be any one of a fractionation tower, a flash tower, or a stripping tower, with a fractionation tower being preferred.

[0056] Furthermore, in the above-mentioned system for producing spinnable bitumen, a separator is provided in the centrifugal separation unit. The separator can be one or more of a centrifugal separator, a centrifugal extractor, a scraper centrifuge, etc., preferably a centrifugal separator.

[0057] Furthermore, in the above-mentioned system for producing spinnable bitumen, the devolatilization unit can be one or more of the following: a vacuum distillation tower, a stripping tower, and a flash distillation tower, with a stripping tower being preferred.

[0058] Furthermore, in the aforementioned system for producing spinnable pitch, the volatile components removed by the devolatilization unit are connected via pipeline to the feed inlet of the hydrogenation separation system in the hydrogenation unit, and are separated together with the hydrogenation reaction products to obtain light fraction, middle fraction and heavy fraction.

[0059] Furthermore, in the above-mentioned system for producing spinnable bitumen, the production system also includes a desolidification unit for desolidifying the aromatic raw material. The aromatic raw material enters the desolidification unit for desolidification before entering the hydrogenation unit. In particular, when the aromatic raw material is a catalytic slurry, desolidification is generally required. The desolidification unit can use one or a combination of several methods such as filtration, centrifugal sedimentation, and flocculation sedimentation, preferably filtration, and more preferably inorganic membrane filtration.

[0060] Compared with existing spinnable bitumen production processes, the method and system for producing spinnable bitumen provided by this invention have one or more of the following technical advantages:

[0061] (1) In the method for producing spinnable bitumen provided by this invention, the products generated by the hydrogenation reaction are treated differently, and the polymerization reaction depth of the aromatic raw materials is controlled step by step, which effectively improves the uniformity of the final spinnable bitumen product. After the middle distillate undergoes a primary thermal reaction and separation, the macromolecular bitumen-containing stream A is mixed with the heavy distillate for a secondary thermal reaction. This avoids the difference in the progress of the thermal polymerization reaction caused by the different molecular sizes of the middle distillate and the heavy distillate, which leads to the problem of excessively wide molecular size distribution in the bitumen-containing stream B, thus solving the problem of unevenness in the final spinnable bitumen product. The aromatic molecules in the light distillate contain a large number of saturated side chains and have a weak ability to thermally polymerize into macromolecules. Sending the light distillate to the secondary thermal reaction unit can provide hydrogen to the system, effectively alleviate the intensity of the system reaction, avoid the local formation of semi-coke, and improve the fluidity and uniformity of the product at high temperatures.

[0062] (2) In the production method of spinnable pitch provided by the present invention, the light material stream with a high degree of polymerization and the volatile components are recycled back to the hydrogenation separation system, and the lighter components are cut into the middle fraction, which serves as a polymerization initiator in the primary thermal reaction unit to promote the primary thermal polymerization reaction and improve the reaction efficiency; while the heavier components are cut into the heavy fraction and sent directly to the secondary thermal reaction unit to improve the overall utilization rate of the aromatic raw materials. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the method for producing spinnable bitumen provided by the present invention.

[0064] Figure 2 This is a molecular weight distribution diagram of the spinnable pitch sample obtained in Example 1.

[0065] Figure 3 The molecular weight distribution diagram of the spinnable pitch sample obtained in Comparative Example 2 is shown. Detailed Implementation

[0066] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0067] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0068] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (e.g., rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0069] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0070] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0071] In this paper, sulfur content was determined by GB / T387 method; total aromatic hydrocarbon content was determined by SH / T0509 method; aromatic carbon content was determined by SH / T0793 method; ash content was determined by GB / T508 method; bitumen softening point was determined by ASTMD 3461 method; toluene insoluble matter was determined by GB / T2292 method; quinoline insoluble matter was determined by GB / T2293 method; and the proportion of anisotropic microstructure was determined by YB / T 077 method.

[0072] like Figure 1As shown, the process flow of the method for producing spinnable bitumen provided by the present invention is as follows: the aromatic-rich raw material 1 enters the desolidification unit 2 for desolidification treatment, and the aromatic-rich raw material 3 after desolidation treatment enters the hydrogenation reactor in the hydrogenation unit (the hydrogenation unit includes a hydrogenation reactor 4 and a hydrogenation separation system 5) for hydrogenation reaction in the presence of hydrogen and catalyst. The hydrogenation reaction product is separated by the hydrogenation separation system 5 to obtain light fraction 13, middle fraction 14 and heavy fraction 15. The middle fraction 14 enters the primary thermal reaction unit 6 (which includes a primary reactor and a primary separator) for the first thermal polymerization treatment. After treatment and separation, it yields a hydrocarbon-containing stream A16 and a bitumen-containing stream A17. The bitumen-containing stream A17, along with the light fraction 13 and the heavy fraction 15, enters the secondary thermal reaction unit 7 (which includes a secondary reactor and a secondary separator) for the second thermal polymerization treatment. After treatment and separation, it yields a hydrocarbon-containing stream B18 and a bitumen-containing stream B19. The bitumen-containing stream B19 enters the settling separation unit 8, where it is separated to yield a hydrocarbon-containing stream C20 and a bitumen-containing stream C21. The hydrocarbon-containing stream C20 continues into the centrifugal separation unit 9, where it is centrifuged to yield a light stream 22 and a heavy stream 23. The light stream 22 is recycled back to the hydrotreating separation system 5, and the heavy stream 23 is recycled back to the settling separation unit 8. The asphalt-containing feedstock C21 enters the devolatilization unit 10, where volatile components 24 are removed by the action of the devolatilization gas 11 to obtain spinnable asphalt 25. Volatile components 24 can be recycled back to the hydrotreating system 5.

[0073] The aromatic raw materials used in the embodiments and comparative examples of this invention are catalytic oil slurry, and the specific properties of the catalytic oil slurry after solidification treatment are shown in Table 1.

[0074] Table 1 Properties of Catalytic Slurry

[0075]

[0076]

[0077] The hydrogenation catalyst used in the hydrogenation unit is the FZC-34BT hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0078] Example 1

[0079] Example 1 uses Figure 1 The method and route for producing spinnable bitumen provided in this paper involves the following steps: After solidification treatment, the catalytic slurry enters the hydrogenation unit. The hydrogenation reaction operates at a temperature of 365°C, a pressure of 7.2 MPa, a hydrogen-to-oil volume ratio of 1:100, and a liquid hourly space velocity (LHSV) of 1.0 h⁻¹. -1The hydrogenation reaction products are separated to obtain light, middle, and heavy fractions. The middle fraction enters the primary thermal reaction unit for the first thermal polymerization treatment at 455℃, 1.2 MPa, for 8 hours, and a stirring rate of 150 r / min, separating hydrocarbon stream A and asphalt-containing stream A. Asphalt-containing stream A, along with the light and heavy fractions, enters the secondary thermal reaction unit for the second thermal polymerization treatment at 440℃, 0.7 MPa, for 6 hours, and a stirring rate of 150 r / min. The process involves separating hydrocarbon-containing stream B and asphalt-containing stream B at a rate of 100 r / min. Asphalt-containing stream B enters a settling separation unit at 310℃ for 12 hours, yielding hydrocarbon-containing stream C and asphalt-containing stream C2. Hydrocarbon-containing stream C2 then enters a centrifugal separation unit at 250℃ and 3000 r / min, resulting in light and heavy streams. The light stream is recycled back to the hydrotreating system, while the heavy stream is recycled back to the settling separation unit. Asphalt-containing stream C2 then enters a devolatilization unit at 380℃ for 5 hours, using nitrogen gas at a flow rate of 3 L / (min·kg asphalt) to remove volatile components, resulting in spinnable asphalt. The volatile components are recycled back to the hydrotreating system.

[0080] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0081] Example 2

[0082] Example 2 adopts Figure 1 The method for producing spinnable bitumen provided in this example differs from that in Example 1 mainly in the different operating conditions of some units. The catalytic slurry, after deconsolidation treatment, enters the hydrogenation unit. The hydrogenation reaction operates at a temperature of 372°C, a pressure of 6.5 MPa, a hydrogen-to-oil volume ratio of 1100, and a liquid hourly space velocity of 1.0 h⁻¹. -1The hydrogenation reaction products are separated to obtain light, middle, and heavy fractions. The middle fraction enters the primary thermal reaction unit for the first thermal polymerization treatment at 446℃, 1.8MPa, for 13 hours, and a stirring rate of 150 r / min, separating hydrocarbon stream A and asphalt-containing stream A. Asphalt-containing stream A, along with the light and heavy fractions, enters the secondary thermal reaction unit for the second thermal polymerization treatment at 438℃, 1.0MPa, for 7 hours, and a stirring rate of 150 r / min. The process involves separating hydrocarbon-containing stream B and asphalt-containing stream B at a speed of 100 r / min. Asphalt-containing stream B enters a settling separation unit at 310℃ for 12 hours, yielding hydrocarbon-containing stream C and asphalt-containing stream C2. Hydrocarbon-containing stream C2 then enters a centrifugal separation unit at 255℃ and 3000 r / min, resulting in light and heavy streams. The light stream is recycled back to the hydrotreating system, while the heavy stream is recycled back to the settling separation unit. Asphalt-containing stream C2 then enters a devolatilization unit at 388℃ for 4 hours, using nitrogen gas at a flow rate of 3 L / (min·kg asphalt) to remove volatile components, resulting in spinnable asphalt. The volatile components are recycled back to the hydrotreating system.

[0083] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0084] Example 3

[0085] The main difference between Example 3 and Example 1 is that the heavy feed stream is not recycled back to the settling separation unit, and the volatile components are not recycled back to the hydrotreating separation system. The catalytic slurry, after solidification treatment, enters the hydrotreating unit. The hydrotreating reaction operates at a temperature of 372°C, a pressure of 6.1 MPa, a hydrogen-to-oil volume ratio of 1200, and a liquid hourly space velocity (LHSV) of 1.0 h⁻¹. -1The hydrogenation reaction products are separated to obtain light, middle, and heavy fractions. The middle fraction enters the primary thermal reaction unit for the first thermal polymerization treatment at 462℃, 0.8MPa, and 6.5h with a stirring rate of 150r / min, separating hydrocarbon stream A and asphalt-containing stream A. Asphalt-containing stream A, along with the light and heavy fractions, enters the secondary thermal reaction unit for the second thermal polymerization treatment at 434℃ and 1.3MPa with a stirring rate of 150r / min. The stirring time was 8 hours, and the stirring rate was 100 r / min, separating hydrocarbon-containing stream B and asphalt-containing stream B. Asphalt-containing stream B entered the sedimentation separation unit, operating at 304℃ for 18 hours, resulting in hydrocarbon-containing stream C and asphalt-containing stream C. Hydrocarbon-containing stream C then entered the centrifugal separation unit, operating at 260℃ and 3000 r / min, resulting in light and heavy streams. The light stream was recycled back to the hydrogenation separation system. Asphalt-containing stream C entered the devolatilization unit, operating at 392℃ for 4.5 hours, using nitrogen as the devolatilization gas at a flow rate of 3 L / (min·kg asphalt), removing volatile components to obtain spinnable asphalt.

[0086] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0087] Comparative Example 1

[0088] Comparative Example 1 is basically the same as Example 2, except that a centrifugal separation unit is not set up, and the hydrocarbon-containing feed stream C is directly discharged from the device. The operating parameters of the hydrogenation unit, primary thermal reaction unit, secondary thermal reaction unit, sedimentation separation unit, and devolatilization unit are the same as those in Example 2.

[0089] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0090] Comparative Example 2

[0091] Comparative Example 2 is basically the same as Example 3, except that the light fraction does not enter the secondary thermal reaction unit for processing. The operating parameters of the hydrogenation unit, primary thermal reaction unit, secondary thermal reaction unit, sedimentation separation unit, centrifugal separation unit, and devolatilization unit are the same as those in Example 3.

[0092] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0093] Table 2 Properties of Major Intermediate Products and Spinnable Pitch

[0094]

[0095]

Claims

1. A method for producing spinnable bitumen, comprising the following steps: (1) Hydrogenation treatment is performed on aromatic-rich raw materials, and the liquid phase products of the hydrogenation reaction are separated to obtain light fraction, middle fraction and heavy fraction; (2) The intermediate fraction from step (1) is subjected to a first thermal polymerization treatment. After the treatment is completed and separated, hydrocarbon-containing stream A and asphalt-containing stream A are obtained. (3) The asphalt-containing stream A from step (2), the light fraction from step (1), and the heavy fraction from step (1) are subjected to a second thermal polymerization treatment. After the treatment is completed and separated, hydrocarbon-containing stream B and asphalt-containing stream B are obtained. (4) After separating the asphalt-containing material stream B from step (3), hydrocarbon-containing material stream C and asphalt-containing material stream C are obtained; (5) Separate the hydrocarbon-containing stream C from step (4) to obtain a light stream and a heavy stream; (6) Process the asphalt-containing stream C from step (4) to remove the volatile components and obtain spinnable asphalt.

2. The method for producing spinnable bitumen according to claim 1, wherein, The total aromatic content in the aromatic-rich raw material in step (1) is 40wt% to 95wt%, preferably 55wt% to 85wt%.

3. The method for producing spinnable bitumen according to claim 1, wherein, The aromatic-rich raw material in step (1) is selected from at least one of catalytic oil slurry, ethylene tar, and coal tar pitch, preferably catalytic oil slurry.

4. The method for producing spinnable bitumen according to claim 1, wherein, The hydrogenation treatment in step (1) is carried out under the following conditions: reaction temperature of 300℃~450℃, preferably 340℃~390℃, pressure of 2MPa~15MPa, preferably 4MPa~8MPa, hydrogen-to-oil volume ratio of 100~2500, preferably 800~1600, and liquid hourly space velocity of 0.1h. -1 ~2.0h -1 Preferably 0.6h -1 ~1.5h -1 .

5. The method for producing spinnable bitumen according to claim 1, wherein, The sulfur content of the liquid phase product of the hydrogenation reaction in step (1) is no more than 0.5 wt%, preferably no more than 0.4 wt%, the 5% distillation temperature is 200℃~450℃, preferably 280℃~400℃, and the aromatic carbon content is 50mol%~85mol%, preferably 60mol%~80mol%.

6. The method for producing spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the middle fraction in step (1) is 300℃~500℃, preferably 400℃~480℃, and the 95% distillation temperature is 470℃~580℃, preferably 500℃~560℃.

7. The method for producing spinnable bitumen according to claim 1, wherein, The first thermal polymerization treatment in step (2) is carried out under the following operating conditions: The processing temperature is 350℃~500℃, preferably 400℃~480℃; And / or, the processing pressure is 0.2 MPa to 5.0 MPa, preferably 0.5 MPa to 3.0 MPa; And / or, the processing time is 2h to 20h, preferably 5h to 15h.

8. The method for producing spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the asphalt-containing material A in step (2) is 400℃~500℃, preferably 430℃~480℃; the softening point is 60℃~120℃; the toluene insoluble content is not greater than 20wt%, preferably not greater than 12wt%; the quinoline insoluble content is not greater than 5wt%, preferably not greater than 0.5wt%.

9. The method for producing spinnable bitumen according to claim 1, wherein, The second thermal polymerization treatment in step (3) is carried out under the following operating conditions: The processing temperature is 350℃~480℃, preferably 400℃~460℃; And / or, the processing pressure is 0 MPa to 5.0 MPa, preferably 0.1 MPa to 1.5 MPa; And / or, the processing time is 1 hour to 20 hours, preferably 2 hours to 10 hours.

10. The method for producing spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the asphalt-containing material stream B in step (3) is 420℃~550℃, preferably 460℃~530℃; the softening point is 100℃~280℃, preferably 180℃~250℃.

11. The method for producing spinnable bitumen according to claim 1, wherein, The separation in step (4) is carried out by sedimentation separation, which is performed under the following operating conditions: temperature is 150℃~400℃, preferably 220℃~330℃; time is 1h~48h, preferably 6h~24h.

12. The method for producing spinnable bitumen according to claim 1, wherein, In step (4), the content of optical anisotropic structure in the asphalt-containing material stream C is greater than or equal to 60 vol, preferably greater than or equal to 90 vol; in step (4), the content of optical anisotropic structure in the hydrocarbon-containing material stream C is less than or equal to 30 vol, preferably less than or equal to 10 vol.

13. The method for producing spinnable bitumen according to claim 1, wherein, The separation in step (5) is carried out by centrifugal separation in the presence of an inert atmosphere, which is nitrogen and / or an inert gas. The operating conditions for centrifugal separation are as follows: the temperature is 180℃~350℃, preferably 200℃~280℃.

14. The method for producing spinnable bitumen according to claim 1, wherein, The content of optical anisotropic microstructure in the lightweight material obtained in step (5) is less than or equal to 5 vol%, preferably less than or equal to 1 vol.

15. The method for producing spinnable bitumen according to claim 1, wherein, The light feed stream obtained in step (5) is recycled together with the liquid phase product of the hydrogenation reaction in step (1) and separated to obtain light fraction, middle fraction and heavy fraction.

16. The method for producing spinnable bitumen according to claim 1, wherein, The heavy material flow obtained in step (5) is recycled and separated together with the asphalt-containing material flow B in step (3).

17. The method for producing spinnable bitumen according to claim 1, wherein, The treatment in step (6) is carried out in the presence of an atmosphere, which is a gas that does not readily react with the asphalt-containing material flow C, selected from at least one of water vapor, nitrogen, helium, and argon, preferably water vapor and / or nitrogen.

18. The method for producing spinnable bitumen according to claim 1, wherein, The processing conditions in step (6) are as follows: the temperature is 330℃~470℃, preferably 350℃~450℃; the time is 1~15h, preferably 2h~8h.

19. The method for producing spinnable bitumen according to claim 1, wherein, The volatile components removed in step (6) are recycled back to be separated together with the liquid phase products of the hydrogenation reaction in step (1), and light fraction, middle fraction and heavy fraction are obtained after separation.

20. A system for producing spinnable bitumen, the system comprising a hydrogenation unit, a primary thermal reaction unit, a secondary thermal reaction unit, a sedimentation separation unit, a centrifugal separation unit, and a devolatilization unit, wherein: The hydrogenation unit includes a hydrogenation reactor and a hydrogenation separation system. The hydrogenation reactor is used to receive aromatic-rich feedstock and hydrogen. The hydrogenation reaction products are separated by the hydrogenation separation system to obtain light fraction, middle fraction and heavy fraction. The primary thermal reaction unit includes a primary reactor and a primary separator. The primary reactor is used to receive the intermediate distillate separated from the hydrogenation unit and perform a first thermal polymerization treatment. The reaction products are separated by the primary separator to obtain a hydrocarbon-containing feed stream A and a bitumen-containing feed stream A. The secondary thermal reaction unit includes a secondary reactor and a secondary separator. The secondary reactor is used to receive the asphalt-containing stream A from the primary thermal reaction unit, the light distillate and the heavy distillate separated from the hydrogenation unit, and perform a second thermal polymerization treatment. The reaction products are separated by the secondary separator to obtain a hydrocarbon-containing stream B and an asphalt-containing stream B. A settling separation unit is used to receive asphalt-containing material stream B from the secondary thermal reaction unit, and separate it to obtain hydrocarbon-containing material stream C and asphalt-containing material stream C. A centrifugal separation unit is used to receive the hydrocarbon-containing material stream C from the sedimentation separation unit, and after separation, obtain a light material stream and a heavy material stream; The devolatilization unit receives the asphalt-containing material stream C from the settling and separation unit, and removes the volatile components in it under the action of devolatilization gas to obtain spinnable asphalt.

21. The system for producing spinnable bitumen according to claim 20, wherein, The light material separated by the centrifugal separation unit flows through a pipeline to the feed inlet of the hydrogenation separation system in the hydrogenation unit, and is separated together with the hydrogenation reaction products to obtain light fraction, middle fraction and heavy fraction.

22. The system for producing spinnable bitumen according to claim 20, wherein, The heavy material stream separated by the centrifugal separation unit is connected to the inlet of the sedimentation separation unit via a pipeline, and is circulated together with the asphalt-containing material stream B for separation.

23. The system for producing spinnable bitumen according to claim 20, wherein, The centrifugal separation unit is equipped with a separator, which is one or more of the following: centrifugal separator, centrifugal extractor, and scraper centrifuge.

24. The system for producing spinnable bitumen according to claim 20, wherein, The devolatilization unit uses one or more of the following: a vacuum distillation tower, a stripping tower, and a flash distillation tower, with a stripping tower being preferred.

25. The system for producing spinnable bitumen according to claim 20, wherein, The volatile components removed by the devolatilization unit are connected to the feed inlet of the hydrogenation separation system in the hydrogenation unit via pipeline, and are separated together with the hydrogenation reaction products to obtain light fraction, middle fraction and heavy fraction.

26. The system for producing spinnable bitumen according to claim 20, wherein, The system for producing spinnable bitumen includes a deconsolidation unit for deconsolidating the aromatic raw material.

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