A process and system for producing spinnable pitch

Abstract

The present application provides a production process and system of spinnable pitch, the production process comprises the following steps: (1) obtaining purified oil and tail oil after thermal treatment of heavy hydrocarbon-containing raw material; (2) obtaining light component and heavy component after hydroprocessing of the purified oil; (3) obtaining first hydrocarbon oil stream and first pitch-containing stream after first thermal polymerization reaction of the obtained heavy component; (4) obtaining second hydrocarbon oil stream and second pitch-containing stream after second thermal polymerization reaction of the first pitch-containing stream; (5) obtaining third hydrocarbon oil stream and third pitch-containing stream after separation of the second pitch-containing stream; (6) obtaining light fraction and heavy fraction after separation of the third hydrocarbon oil stream; (7) obtaining gas phase stream and spinnable pitch after devolatilization treatment of the third pitch-containing stream. The present application also provides a production system of spinnable pitch. The obtained spinnable pitch has suitable softening point and high content of large lamellar structure, and solves the problem that the softening point and the content of anisotropic structure cannot be considered simultaneously.

Description

Technical Field

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

[0002] Spinable pitch is one of the raw materials for producing pitch-based carbon fiber, and its properties directly affect the carbon fiber production process and product performance. Catalytic slurry is rich in aromatic hydrocarbons, making it a high-quality raw material for preparing spinable pitch. The direct thermal polycondensation method has the advantages of simple process flow and ease of large-scale industrial production, and is currently the mainstream process for converting catalytic slurry into spinable pitch.

[0003] Patent CN114106863A discloses a mesophase pitch for spinning and its preparation method. The wax oil fraction produced by liquid-phase hydrogenation of ethylene cracked tar in a suspension bed is used as raw material. The contents of aromatics and tricyclic and above aromatics are 80wt%-90wt% and 50wt%-70wt%, respectively. The wax oil fraction is subjected to vacuum distillation to obtain a fraction oil rich in aromatics. The first thermal polymerization reaction is carried out to obtain an intermediate product. After a second thermal polymerization reaction, the mesophase pitch for spinning is obtained.

[0004] 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. Summary of the Invention

[0005] During the research process, the applicant discovered that the softening point and anisotropic microstructure content of asphalt are key factors affecting its spinnability. When the anisotropic microstructure content of the asphalt approaches 100%, its spinnability reaches its optimal level. However, a high anisotropic microstructure content is accompanied by a high softening point, which indicates that the asphalt molecules are relatively large, resulting in poor thermal stability and fluidity during spinning, which is detrimental to continuous spinning. Therefore, how to prepare spinnable asphalt with a high anisotropic microstructure content while maintaining a low softening point is an urgent problem to be solved.

[0006] The main objective of this invention is to provide a production process and system for spinnable bitumen. The production process can effectively control the polymerization depth of aromatic molecules, avoid the formation of large molecules with poor thermal stability and high degree of polymerization, and obtain spinnable bitumen with a suitable softening point and a high content of large plate-like structures, thereby solving the problem of not being able to simultaneously achieve both softening point and anisotropic structure content.

[0007] The first aspect of this invention provides a process for producing spinnable bitumen, the process comprising the following steps:

[0008] (1) Heat treatment is performed on heavy hydrocarbon-containing raw materials, and the heat treatment reaction products are separated to obtain purified oil and tail oil;

[0009] (2) In the presence of hydrogen, the purified oil obtained in step (1) is subjected to hydrogenation treatment, and the hydrogenation reaction products are separated to obtain light components and heavy components.

[0010] (3) The heavy components obtained in step (2) enter the first thermal polymerization reaction unit for primary thermal polymerization reaction, and after the reaction, the first hydrocarbon oil stream and the first asphalt-containing stream are obtained.

[0011] (4) The first asphalt-containing material stream obtained in step (3) enters the second thermal polymerization reaction unit for a secondary thermal polymerization reaction, and after the reaction, a second hydrocarbon oil stream and a second asphalt-containing material stream are obtained.

[0012] (5) The second asphalt-containing material stream obtained in step (4) is separated to obtain a third hydrocarbon oil stream and a third asphalt-containing material stream;

[0013] (6) The third hydrocarbon oil stream obtained in step (5) is separated to obtain light and heavy fractions;

[0014] (7) After the third bitumen-containing material stream in step (5) is subjected to devolatilization treatment, gaseous material stream and spinnable bitumen are obtained.

[0015] Furthermore, as some preferred embodiments, the heavy hydrocarbon-containing raw material in step (1) can be selected from at least one of catalytic slurry, ethylene tar, coal tar pitch, etc., preferably catalytic slurry; even further, the heavy hydrocarbon-containing raw material is preferably subjected to a desolidification treatment, which can be one or a combination of filtration, centrifugal sedimentation, flocculation sedimentation, etc., preferably filtration, and even more preferably inorganic membrane filtration. The ash content of the heavy hydrocarbon-containing raw material after the desolidification treatment is not greater than 80 ppm, preferably not greater than 40 ppm.

[0016] Furthermore, as some preferred embodiments, the heat treatment in step (1) can be carried out using one or more of the following reactor types, including but not limited to a batch reactor, a tower reactor, a tubular reactor, etc., with a tubular reactor being preferred.

[0017] Furthermore, as some preferred embodiments, the heat treatment operating conditions in step (1) are generally controlled as follows: the heat treatment temperature is 350℃~500℃, preferably 390℃~470℃; and / or,

[0018] The heat treatment pressure is 0 MPa to 5.0 MPa, preferably 0.1 MPa to 1.0 MPa; and / or,

[0019] The residence time of heavy hydrocarbon feedstock in the reactor is generally controlled to be 10s to 3600s, preferably 30s to 150s.

[0020] Furthermore, as some preferred embodiments, the separation of the heat treatment reaction products in step (1) can be achieved by distillation, preferably by vacuum distillation. Specific operating conditions can be adjusted according to actual needs, and those skilled in the art can determine the operating conditions based on the properties of the raw materials and requirements. Further, after separation of the heat treatment reaction products, purified oil and tail oil are obtained, wherein the 95% distillation temperature of the purified oil is 500℃~600℃, preferably 520℃~560℃; the toluene-insoluble content is not greater than 2.0wt%; the quinoline-insoluble content is not greater than 0.1wt%; and the ash content is not greater than 20ppm.

[0021] Furthermore, as some preferred embodiments, the hydrogenation treatment of the purified oil obtained in step (1) described in step (2) can be carried out by one or a combination of existing hydrogenation processes such as fixed-bed hydrogenation process, suspended-bed hydrogenation process, and fluidized-bed hydrogenation process, with fixed-bed hydrogenation process being preferred.

[0022] Furthermore, as some preferred embodiments, the hydrogenation treatment operating conditions in step (2) are controlled as follows: the reaction temperature is 300℃~450℃, preferably 340℃~390℃; the reaction 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 Furthermore, the sulfur content of the hydrogenation reaction product after hydrogenation treatment is no more than 0.5 wt%, preferably no more than 0.4 wt%; the aromatic carbon content is 50 wt% to 85 wt%, preferably 60 wt% to 80 wt%.

[0023] Furthermore, as some preferred embodiments, the 5% distillation temperature of the heavy components in step (2) is 380°C to 500°C, preferably 420°C to 480°C.

[0024] Furthermore, as some preferred embodiments, the hydrotreating of the purified oil obtained in step (1) in step (2) is carried out in the presence of a hydrotreating catalyst. The hydrotreating catalyst includes a support and an active component. The support is generally an inorganic refractory oxide such as alumina, and the active component generally includes oxides of Group VIB and / or Group VIII metals. The hydrotreating catalyst can be a commercially available catalyst in the art, such as the FZC and / or FH series hydrotreating catalysts developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0025] Furthermore, as some preferred embodiments, the operating conditions for the primary thermal polymerization reaction in step (3) are as follows: the reaction temperature is 350℃~480℃, preferably 400℃~460℃; and / or,

[0026] The reaction pressure is 0.2 MPa to 5.0 MPa, preferably 0.2 MPa to 2.0 MPa; and / or,

[0027] The reaction time is 2h to 20h, preferably 3h to 15h.

[0028] Furthermore, as some preferred embodiments, and more preferably, the thermal polymerization reaction in the first thermal polymerization reaction unit is carried out under fully stirred conditions. More specifically, the stirring rate can be controlled to be 50 r / min to 800 r / min, preferably 60 r / min to 300 r / min.

[0029] Furthermore, as some preferred embodiments, the 5% distillation temperature of the first bitumen-containing material stream in step (3) 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%.

[0030] Furthermore, as some preferred embodiments, the operating conditions for the secondary thermal polymerization reaction in step (4) are as follows: the operating temperature is 350℃~480℃, preferably 400℃~460℃; and / or,

[0031] The pressure is 0 MPa to 5.0 MPa, preferably 0.1 MPa to 1.5 MPa; and / or,

[0032] The time is 1 hour to 20 hours, preferably 2 hours to 10 hours.

[0033] Furthermore, as some preferred embodiments, the reaction in the second thermal polymerization reaction unit is carried out under fully stirred conditions, and the specific stirring rate can generally be controlled to be 50 r / min to 800 r / min, preferably 50 r / min to 200 r / min.

[0034] Furthermore, as some preferred embodiments, the 5% distillation temperature of the second bitumen-containing stream in step (4) is 420°C to 550°C, preferably 460°C to 530°C. The softening point is 100°C to 270°C, preferably 180°C to 250°C.

[0035] Furthermore, as some preferred embodiments, the separation in step (5) is sedimentation separation, which can be carried out in a sedimentation tower. More specifically, the operating conditions for sedimentation separation are: sedimentation temperature of 150℃~400℃, preferably 220℃~330℃; sedimentation time of 1h~48h, preferably 6h~24h.

[0036] Furthermore, as some preferred embodiments, the proportion of optical anisotropic microstructure in the third bituminous material stream in step (5) is greater than or equal to 60 vol%, preferably greater than or equal to 90 vol%.

[0037] Furthermore, as some preferred embodiments, the content of optical anisotropic microstructure in the third hydrocarbon stream in step (5) is less than or equal to 30 vol%, preferably less than or equal to 10 vol%.

[0038] Furthermore, as some preferred embodiments, the separation in step (6) is preferably carried out by centrifugal separation, and the further centrifugal separation is carried out under the protection of an inert atmosphere. The operating temperature of the centrifugal separation is 180℃~350℃, preferably 200℃~280℃; the rotation speed is 1000r / min~10000r / min, preferably 2000r / min~5000r / min; 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.

[0039] Furthermore, as some preferred embodiments, the content of optically anisotropic microstructure in the light fraction in step (6) is no more than 5 vol%, preferably no more than 1 vol%.

[0040] Furthermore, as some preferred embodiments, the light fraction in step (6) is recycled back to the second thermal polymerization reaction unit for further reaction.

[0041] Furthermore, as some preferred embodiments, the heavy fraction in step (6) is preferably recycled back and separated together with the second bitumen-containing stream.

[0042] Furthermore, as some preferred embodiments, the devolatilization process in step (7) is carried out in the presence of a devolatilization atmosphere, which is a gas that does not readily react with A asphalt; specifically, it can be selected from one or a mixture of several of water vapor, nitrogen, helium, and argon, preferably water vapor and / or nitrogen.

[0043] Furthermore, as some preferred embodiments, the operating conditions for the devolatilization treatment in step (7) are as follows: the devolatilization treatment temperature is 330℃~470℃, preferably 350℃~450℃, the treatment time is 1~15h, preferably 2h~8h, and the devolatilization atmosphere flow rate is 1~10L / (min·kg asphalt), preferably 1~5L / (min·kg asphalt).

[0044] Furthermore, as some preferred embodiments, the gaseous material stream obtained from the devolatilization process in step (7) is preferably recycled back to undergo a secondary thermal polymerization reaction together with the first asphalt-containing material stream.

[0045] A second aspect of the present invention provides a production system for spinnable bitumen, the production system comprising a heat treatment unit, a hydrogenation reaction unit, a first thermal polymerization reaction unit, a second thermal polymerization reaction unit, a settling tower, a centrifugal separation unit, and a devolatilization unit, wherein:

[0046] The heat treatment unit includes a heat treatment reactor and a heat treatment separation system. The heat treatment reactor is used to receive heavy hydrocarbon-containing raw materials and heat treat them. The reaction products obtained after heat treatment enter the heat treatment separation system for separation to obtain purified oil and tail oil.

[0047] The hydrogenation reaction unit includes a hydrogenation reactor and a hydrogenation fractionation tower. The hydrogenation reactor is used to receive hydrogen and purified oil from the heat treatment separation system. The hydrogenation reaction products enter the hydrogenation fractionation tower for separation to obtain light components and heavy components.

[0048] The first thermal polymerization reaction unit includes a first thermal polymerization reactor and a first fractionation tower. The heavy components from the hydrogenation fractionation tower enter the first thermal polymerization reactor for reaction. The reaction products are separated by the first fractionation tower to obtain a first hydrocarbon oil stream and a first asphalt-containing stream.

[0049] The second thermal polymerization reaction unit includes a second thermal polymerization reactor and a second fractionation tower. The first asphalt-containing material stream from the first fractionation tower enters the second thermal polymerization reactor for reaction. The reaction products are separated by the second fractionation tower to obtain a second hydrocarbon oil stream and a second asphalt-containing material stream.

[0050] A settling tower is used to receive the second bituminous stream from the second fractionation tower and separate it to obtain a third hydrocarbon oil stream and a third bituminous stream.

[0051] The centrifugal separation unit is used to receive the third hydrocarbon oil stream from the settling tower and separate it into light and heavy fractions.

[0052] The devolatilization unit receives the third bituminous material stream from the settling tower, and after devolatilization, obtains a gaseous material stream and spinnable bitumen.

[0053] Furthermore, as some preferred embodiments, the heat treatment reactor can be one or a combination of several of the following: a batch reactor, a tower reactor, a tubular reactor, etc., with a tubular reactor being preferred.

[0054] Furthermore, as some preferred embodiments, the heat treatment separation system in the heat treatment unit may employ a vacuum distillation column.

[0055] Furthermore, as some preferred embodiments, 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, and a fluidized-bed hydrogenation reactor, with a fixed-bed hydrogenation reactor being preferred.

[0056] Furthermore, as some preferred embodiments, both the first thermal polymerization reactor and the second thermal polymerization reactor can be batch reactors, preferably batch reactors equipped with stirring equipment.

[0057] Furthermore, as some preferred embodiments, the centrifugal separation unit is provided with a separator, which can be one or more of a centrifugal separator, a centrifugal extractor, a scraper centrifuge, etc., preferably a centrifugal separator.

[0058] Furthermore, as some preferred embodiments, the light fraction separated by the centrifugal separation unit is connected via a pipeline to the feed inlet of the second thermal polymerization reactor in the second thermal polymerization reaction unit, and undergoes a secondary thermal polymerization reaction together with the first asphalt-containing material stream.

[0059] Furthermore, as some preferred embodiments, the heavy fraction separated by the centrifugal separation unit is connected to the feed inlet of the settling tower via a pipeline and is separated together with the second asphalt-containing material stream.

[0060] Furthermore, as some preferred embodiments, the gaseous material flow obtained after the devolatilization treatment in the devolatilization unit is connected to the feed inlet of the second thermal polymerization reactor in the second thermal polymerization reaction unit via a pipeline, and undergoes a secondary thermal polymerization reaction together with the first asphalt-containing material flow.

[0061] Furthermore, as some preferred embodiments, the devolatilization unit may be one or more of a vacuum distillation tower, a stripping tower, a flash distillation tower, etc., with a stripping tower being preferred.

[0062] Furthermore, as some preferred embodiments, a desolidification unit is also included for desolidifying heavy hydrocarbon-containing raw materials. The heavy hydrocarbon-containing raw materials enter the desolidification unit for desolidification treatment before entering the heat treatment unit. In particular, when heavy hydrocarbon-containing raw materials are catalytic slurry, desolidification treatment is generally required. The desolidification unit can adopt one or a combination of several methods such as filtration, centrifugal sedimentation, and flocculation sedimentation. Filtration is preferred, and inorganic membrane filtration is even more preferred.

[0063] Compared with existing spinnable bitumen production processes, the spinnable bitumen production process and system provided by this invention have one or more of the following technical advantages:

[0064] (1) In the production process of spinnable asphalt provided, both the light and heavy components obtained from the hydrogenation reaction are fully and effectively utilized. The heavy components generated by the hydrogenation reaction serve as the main raw material for spinnable asphalt, which are polymerized into macromolecules stepwise in the first and second thermal polymerization reaction units, and then separated to obtain spinnable asphalt. The light components generated by the hydrogenation reaction have aromatic molecules rich in saturated side chains, which play a role in hydrogen donation in the second thermal polymerization reaction. Their introduction can regulate and ensure that the second thermal polymerization reaction proceeds slowly, effectively slowing down the formation rate of quinoline insolubles. While gradually increasing the softening point and anisotropic structure content of the spinnable asphalt, it avoids the premature formation of a large number of macromolecules with excessively high polymerization degrees.

[0065] (2) In the production process of spinnable asphalt provided, the molecular size of the feed is controlled by adjusting the content of optical anisotropic structure of the feed in the second thermal polymerization reaction unit, so as to avoid excessively large molecules from being highly polymerized in the second thermal polymerization reaction unit, thereby generating asphalt components with poor thermal stability and high softening point. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the production process of spinnable bitumen provided by the present invention.

[0067] Figure 2 This is a polarized microscope image of the spinnable pitch sample obtained in Example 1.

[0068] Figure 3 This is a molecular weight distribution diagram of the spinnable pitch sample obtained in Example 1.

[0069] Figure 4 This is a polarized microscope image of the spinnable pitch sample obtained in Example 2.

[0070] Figure 5 The image shown is a polarized microscope photograph of the spinnable pitch sample obtained in Comparative Example 1.

[0071] Figure 6 The image shows a polarized microscope photograph of the spinnable pitch sample obtained in Comparative Example 2.

[0072] Figure 7 The molecular weight distribution diagram of the spinnable pitch sample obtained in Comparative Example 2 is shown. Detailed Implementation

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] like Figure 1As shown, the production process of spinnable asphalt provided by the present invention is as follows: Heavy hydrocarbon-containing raw material 1 is optionally fed into the desolidification unit 2 for desolidation treatment. After desolidation treatment, the heavy hydrocarbon-containing raw material 12 is fed into the heat treatment reactor in the heat treatment unit 3 (the heat treatment unit 3 includes a heat treatment reactor and a heat treatment separation system) for heat treatment. The reaction products obtained after heat treatment are separated in the heat treatment separation system to obtain purified oil 14 and tail oil 13. Tail oil 13 can be discharged externally. Purified oil 14 is fed into the hydrogenation reactor 4 in the hydrogenation reaction unit (the hydrogenation reaction unit includes a hydrogenation reactor 4 and a hydrogenation fractionation tower 5). Under the action of hydrogen and hydrogenation catalyst, a hydrogenation reaction occurs. The hydrogenation reaction product 15 is fed into the hydrogenation fractionation tower 5 and separated to obtain light component 16 and heavy component 17. The heavy component 17 enters the first thermal polymerization reactor in the first thermal polymerization reaction unit 6 (which includes a first thermal polymerization reactor and a first fractionation tower) to undergo a first-stage thermal polymerization reaction. The reaction products are separated by the first fractionation tower to obtain a first hydrocarbon oil stream 18 and a first asphalt-containing stream 19. The first asphalt-containing stream 19 then enters the second thermal polymerization reactor in the second thermal polymerization reaction unit 7 (which includes a second thermal polymerization reactor and a second fractionation tower) to undergo a second-stage thermal polymerization reaction. The reaction products are separated by the second fractionation tower to obtain a second hydrocarbon oil stream 20 and a second asphalt-containing stream 21. The second asphalt-containing stream 21 then enters the settling tower 8 for settling and separation to obtain a third hydrocarbon oil stream 23 and a third asphalt-containing stream 22. The third hydrocarbon stream 23 enters the centrifugal separation unit 9 to separate light fraction 27 and heavy fraction 26. Heavy fraction 26, along with the second bitumen-containing stream 21, returns to the settling tower 8. Light fraction 27 is connected via pipeline to the inlet of the second thermal polymerization reactor in the second thermal polymerization reaction unit 7, where it undergoes a secondary thermal polymerization reaction together with the first bitumen-containing stream. The third bitumen-containing stream 22 contacts the devolatilization gas 11 in the devolatilization unit 10, undergoing devolatilization treatment under the action of the devolatilization gas to obtain a gaseous stream 24 and spinnable bitumen 25. The gaseous stream 24, light fraction 27, and light component 16, together with the first bitumen-containing stream 19, enter the second thermal polymerization reactor in the second thermal polymerization reaction unit 7 to undergo a secondary thermal polymerization reaction.

[0080] The heavy hydrocarbon-containing feedstock used in the embodiments and comparative examples of this invention is catalytic slurry oil. The specific properties of the catalytic slurry oil after solidification treatment are shown in Table 1. The hydrogenation catalyst used in the hydrogenation unit is the FZC-34BT hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0081] Table 1 Properties of Catalytic Slurry

[0082]

[0083]

[0084] Example 1

[0085] Example 1 uses Figure 1 The production process of spinnable bitumen is shown. After solidification treatment, the catalytic oil slurry enters a heat treatment unit. The heat treatment reaction operation temperature is 448℃, the pressure is 0.35MPa, and the residence time is 60s. After separation, purified oil is obtained. The purified oil enters a hydrogenation reaction unit. The hydrogenation reaction operation temperature is 368℃, the pressure is 6.5MPa, the hydrogen-to-oil volume ratio is 1200, and the liquid hourly space velocity is 0.9h⁻¹. -1 After separation, light and heavy components are obtained. The heavy component enters the first thermal polymerization reaction unit for primary thermal polymerization at 441℃, 1.3MPa, 14h, and 150r / min, separating the first asphalt-containing stream. The first asphalt-containing stream enters the second thermal polymerization reaction unit for secondary thermal polymerization at 443℃, 0.5MPa, 6h, and 100r / min, separating the second asphalt-containing stream. The second asphalt-containing stream enters the settling tower at 303℃ for 15h, separating into a third hydrocarbon oil stream and a third asphalt-containing stream. The third hydrocarbon oil stream enters the centrifugal separation unit at 262℃ and 3000r / min, separating into light and heavy fractions. The third asphalt-containing stream enters the devolatilization unit at 391℃ for 6h, with nitrogen as the devolatilization gas at a flow rate of 3L / (min·kg asphalt). The gaseous stream, light fraction, and light components are mixed together with the first asphalt-containing stream and enter the second thermal polymerization reaction unit, while the heavy fraction is recycled back to the settling tower.

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

[0087] Example 2

[0088] Example 2 is the same as Example 1, using the process route for preparing spinnable bitumen provided by this invention. The main difference lies in the operating conditions of the first and second thermal polymerization reaction units. The temperature of the first thermal polymerization reaction unit is 447°C, the pressure is 0.9 MPa, the time is 8 hours, and the stirring rate is 150 r / min; the temperature of the second thermal polymerization reaction unit is 438°C, the pressure is 0.6 MPa, the time is 7 hours, and the stirring rate is 100 r / min.

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

[0090] Example 3

[0091] Example 3 uses the process route for preparing spinnable bitumen provided by this invention. The difference from Example 1 is that the gaseous stream is not recycled back to the second thermal condensation reaction unit, and the heavy fraction is not recycled back to the settling tower. The catalytic slurry, after desolidification, enters the heat treatment unit. The heat treatment reaction operation temperature is 436℃, the pressure is 0.45MPa, and the residence time is 80s. After separation, purified oil is obtained. The purified oil enters the hydrogenation reaction unit. The hydrogenation reaction operation temperature is 362℃, the pressure is 7.2MPa, the hydrogen-to-oil volume ratio is 1200, and the liquid hourly space velocity is 1.0 h⁻¹. -1 After separation, light and heavy components are obtained. The heavy component enters the first thermal polymerization reaction unit for primary thermal polymerization at 450℃, 0.8MPa, and 8h with a stirring rate of 150r / min, resulting in the separation of the first asphalt-containing stream. The first asphalt-containing stream enters the second thermal polymerization reaction unit for secondary thermal polymerization at 435℃, 1.2MPa, and 6h with a stirring rate of 100r / min, resulting in the separation of the second asphalt-containing stream. The second asphalt-containing stream enters the settling tower at 308℃ for 13h, separating into a third hydrocarbon oil stream and a third asphalt-containing stream. The third hydrocarbon oil stream enters the centrifugal separation unit at 257℃ and 3000r / min, separating into light and heavy fractions. The third asphalt-containing stream enters the devolatilization unit at 402℃ for 5h, with nitrogen as the devolatilization gas at a flow rate of 3L / (min·kg asphalt). The light fraction and light components are mixed together with the first asphalt-containing material stream and then enter the second thermal polymerization reaction unit.

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

[0093] Comparative Example 1

[0094] Comparative Example 1 is basically the same as Example 3, except that a centrifugal separation unit is not set up, the third hydrocarbon oil stream is not separated, and the gaseous stream generated by the devolatilization unit is not recycled back to the second thermal polymerization reaction unit. The operating parameters of the heat treatment unit, hydrogenation reaction unit, first thermal polymerization reaction unit, second thermal polymerization reaction unit, settling tower, and devolatilization unit are the same as those of Example 1.

[0095] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0096] Comparative Example 2

[0097] Comparative Example 2 is essentially the same as Example 3, except that the light component generated by the hydrogenation reaction does not enter the second thermal polymerization reaction unit. The operating parameters of the heat treatment unit, hydrogenation reaction unit, first thermal polymerization reaction unit, second thermal polymerization reaction unit, settling tower, centrifugal separation unit, and devolatilization unit are the same as those in Example 3.

[0098] The main intermediate products and properties of spinnable pitch are listed in Table 2.

[0099] Table 2 Properties of Major Intermediate Products and Spinnable Pitch

[0100]

[0101]

Claims

1. A process for producing spinnable bitumen, the process comprising the following steps: (1) Heat treatment is performed on heavy hydrocarbon-containing raw materials, and the heat treatment reaction products are separated to obtain purified oil and tail oil; (2) In the presence of hydrogen, the purified oil obtained in step (1) is subjected to hydrogenation treatment, and the hydrogenation reaction products are separated to obtain light components and heavy components; (3) The heavy components obtained in step (2) enter the first thermal polymerization reaction unit for primary thermal polymerization reaction, and after the reaction, the first hydrocarbon oil stream and the first asphalt-containing stream are obtained; (4) The first asphalt-containing material stream obtained in step (3) enters the second thermal polymerization reaction unit for a secondary thermal polymerization reaction, and after the reaction, a second hydrocarbon oil stream and a second asphalt-containing material stream are obtained. (5) The second asphalt-containing material stream obtained in step (4) is separated to obtain a third hydrocarbon oil stream and a third asphalt-containing material stream; (6) The third hydrocarbon oil obtained in step (5) is separated to obtain light and heavy fractions; (7) After the third bitumen-containing material stream in step (5) is subjected to devolatilization treatment, gaseous material stream and spinnable bitumen are obtained.

2. The production process of spinnable bitumen according to claim 1, wherein, The heavy hydrocarbon-containing 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.

3. The production process of spinnable bitumen according to claim 1, wherein, In step (1), the heavy hydrocarbon raw material is first subjected to a desolidification treatment. The ash content of the heavy hydrocarbon raw material after the desolidification treatment is not greater than 80 ppm, preferably not greater than 40 ppm.

4. The production process of spinnable bitumen according to claim 1, wherein, The heat treatment operating conditions in step (1) are as follows: the heat treatment temperature is 350℃~500℃, preferably 390℃~470℃; and / or, The heat treatment pressure is 0 MPa to 5.0 MPa, preferably 0.1 MPa to 1.0 MPa; and / or, The residence time of heavy hydrocarbon feedstock in the reactor is 10s to 3600s, preferably 30s to 150s.

5. The production process of spinnable bitumen according to claim 1, wherein, The 95% distillation temperature of the purified oil is 500℃~600℃, preferably 520℃~560℃; the content of toluene insoluble matter is not greater than 2.0wt%, the content of quinoline insoluble matter is not greater than 0.1wt%, and the ash content is not greater than 20ppm.

6. The production process of spinnable bitumen according to claim 1, wherein, The hydrotreating operating conditions in step (2) are controlled as follows: reaction temperature is 300℃~450℃, preferably 340℃~390℃; reaction pressure is 2MPa~15MPa, preferably 4MPa~8MPa; hydrogen-to-oil volume ratio is 100~2500, preferably 800~1600; and liquid hourly space velocity is 0.1h. -1 ~2.0h -1 Preferably 0.6h -1 ~1.5h -1 .

7. The production process of spinnable bitumen according to claim 1, wherein, The sulfur content of the hydrogenation reaction product after hydrogenation treatment is no more than 0.5 wt%, preferably no more than 0.4 wt%, and the aromatic carbon content is 50 wt% to 85 wt%, preferably 60 wt% to 80 wt%.

8. The production process of spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the heavy components in step (2) is 380℃~500℃, preferably 420℃~480℃.

9. The production process of spinnable bitumen according to claim 1, wherein, The operating conditions for the primary thermal polymerization reaction in step (3) are as follows: the reaction temperature is 350℃~480℃, preferably 400℃~460℃; and / or, the reaction pressure is 0.2MPa~5.0MPa, preferably 0.2MPa~2.0MPa; And / or, the reaction time is 2h to 20h, preferably 3h to 15h.

10. The production process of spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the first asphalt-containing material stream in step (3) 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%.

11. The production process of spinnable bitumen according to claim 1, wherein, The operating conditions for the secondary thermal polymerization reaction in step (4) are as follows: the operating temperature is 350℃~480℃, preferably 400℃~460℃; and / or the pressure is 0MPa~5.0MPa, preferably 0.1MPa~1.5MPa; And / or, the time is 1h to 20h, preferably 2h to 10h.

12. The production process of spinnable bitumen according to claim 1, wherein, The 5% distillation temperature of the second asphalt-containing material stream in step (4) is 420℃~550℃, preferably 460℃~530℃; the softening point is 100℃~270℃, preferably 180℃~250℃.

13. The production process of spinnable bitumen according to claim 1, wherein, The separation in step (5) is sedimentation separation. The operating conditions for sedimentation separation are: sedimentation temperature of 150℃~400℃, preferably 220℃~330℃; sedimentation time of 1h~48h, preferably 6h~24h.

14. The production process of spinnable bitumen according to claim 1, wherein, The separation described in step (6) is carried out by centrifugal separation, which is conducted under an inert atmosphere. The operating temperature of the centrifugal separation is 180℃~350℃, preferably 200℃~280℃.

15. The production process of spinnable bitumen according to claim 1, wherein, The light fraction in step (6) is recycled back to the second thermal polymerization reaction unit for further reaction.

16. The production process of spinnable bitumen according to claim 1, wherein, The heavy fraction in step (6) is recycled back and separated together with the second asphalt-containing material stream.

17. The production process of spinnable bitumen according to claim 1, wherein, In step (7), the devolatilization process is carried out in the presence of a devolatilization atmosphere, which is a gas that does not readily react with asphalt; selected from one or a mixture of several of water vapor, nitrogen, helium, and argon, with water vapor and / or nitrogen being preferred.

18. The production process of spinnable bitumen according to claim 1, wherein, The operating conditions for the devolatilization treatment in step (7) are as follows: the devolatilization treatment temperature is 330℃~470℃, preferably 350℃~450℃, and the treatment time is 1~15h, preferably 2h~8h.

19. The production process of spinnable bitumen according to claim 1, wherein, The gaseous material stream obtained from the devolatilization process in step (7) is recycled back to undergo a secondary thermal polymerization reaction together with the first asphalt-containing material stream.

20. A production system for spinnable bitumen, the production system comprising a heat treatment unit, a hydrogenation reaction unit, a first thermal polymerization reaction unit, a second thermal polymerization reaction unit, a settling tower, a centrifugal separation unit, and a devolatilization unit, wherein: The heat treatment unit includes a heat treatment reactor and a heat treatment separation system. The heat treatment reactor is used to receive heavy hydrocarbon-containing raw materials and heat treat them. The reaction products obtained after heat treatment enter the heat treatment separation system for separation to obtain purified oil and tail oil. The hydrogenation reaction unit includes a hydrogenation reactor and a hydrogenation fractionation tower. The hydrogenation reactor is used to receive hydrogen and purified oil from the heat treatment separation system. The hydrogenation reaction products enter the hydrogenation fractionation tower for separation to obtain light components and heavy components. The first thermal polymerization reaction unit includes a first thermal polymerization reactor and a first fractionation tower. The heavy components from the hydrogenation fractionation tower enter the first thermal polymerization reactor for reaction. The reaction products are separated by the first fractionation tower to obtain a first hydrocarbon oil stream and a first asphalt-containing stream. The second thermal polymerization reaction unit includes a second thermal polymerization reactor and a second fractionation tower. The first asphalt-containing material stream from the first fractionation tower enters the second thermal polymerization reactor for reaction. The reaction products are separated by the second fractionation tower to obtain a second hydrocarbon oil stream and a second asphalt-containing material stream. A settling tower is used to receive the second bituminous stream from the second fractionation tower and separate it to obtain a third hydrocarbon oil stream and a third bituminous stream. The centrifugal separation unit is used to receive the third hydrocarbon oil stream from the settling tower and separate it into light and heavy fractions. The devolatilization unit receives the third bituminous material stream from the settling tower, and after devolatilization, obtains a gaseous material stream and spinnable bitumen.

21. The spinnable bitumen production system according to claim 20, wherein, A heat treatment reactor is one or a combination of several of the following: a batch reactor, a tower reactor, and a tubular reactor, with a tubular reactor being preferred.

22. The spinnable bitumen production system 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.

23. The spinnable bitumen production system according to claim 20, wherein, The light fraction separated by the centrifugal separation unit is connected to the feed inlet of the second thermal polymerization reactor in the second thermal polymerization reaction unit via a pipeline, and undergoes a secondary thermal polymerization reaction together with the first asphalt-containing material stream.

24. The spinnable bitumen production system according to claim 20, wherein, The heavy fraction separated by the centrifugal separation unit is connected to the feed inlet of the settling tower via a pipeline and is separated together with the second asphalt-containing material stream.

25. The spinnable bitumen production system according to claim 20, wherein, After the devolatilization process in the devolatilization unit, the resulting gaseous material flow is connected to the feed inlet of the second thermal polymerization reactor in the second thermal polymerization reaction unit via a pipeline, and undergoes a secondary thermal polymerization reaction together with the first asphalt-containing material flow.

26. The spinnable bitumen production system according to claim 20, wherein, The devolatilization unit can be one or more of the following: a vacuum distillation tower, a stripping tower, and a flash distillation tower.

27. The spinnable bitumen production system according to claim 20, wherein, The production system for spinnable bitumen also includes a desolidification unit, which is used to desolidify heavy hydrocarbon-containing raw materials. The heavy hydrocarbon-containing raw materials enter the desolidification unit for desolidification before entering the heat treatment unit. The desolidification unit adopts one or a combination of filtration, centrifugal sedimentation, and flocculation sedimentation methods.

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