Method and system for preparing starting material of carbon material by means of staged hydrogenation of heavy oil

Abstract

Disclosed in the present invention is a method and system for preparing a starting material of a carbon material by means of staged hydrogenation of heavy oil. The method comprises: sequentially performing pretreatment, hydrogenation pretreatment, and vacuum distillation on heavy oil; performing selective hydrogenation treatment on a middle distillate obtained by vacuum distillation; performing hydrogenation ring-opening treatment on a heavy distillate obtained by vacuum distillation; and then performing post-treatment on a product obtained by the selective hydrogenation treatment and a product obtained by the hydrogenation ring-opening treatment, so as to obtain a starting material of a carbon material. The starting material of the carbon material prepared by the present invention has a relatively high content of tricyclic aromatic hydrocarbon and a relatively high content of tetracyclic aromatic hydrocarbon, and a relatively low content of impurities, and can be used for preparing a high-quality carbon material.

Description

A method and system for preparing carbon material feedstock by staged hydrogenation of heavy oil Technical Field

[0001] This invention relates to the field of carbon materials technology, and specifically to a method and system for preparing carbon material raw materials by staged hydrogenation of heavy oil. Background Technology

[0002] In recent years, with the development of ultra-high power electric arc furnace steelmaking technology, the demand for high-power and ultra-high power graphite electrodes has increased significantly. Needle coke, with its advantages of low resistivity, small coefficient of thermal expansion, strong impact resistance, high mechanical strength, and good oxidation resistance, has become an ideal raw material for high-power and ultra-high power electrodes. Furthermore, with the development of new energy technologies, the demand for carbon materials for battery anodes is strong and has high added value.

[0003] Furthermore, mesophase pitch is a pitch-like mixture composed of polycyclic aromatic hydrocarbons and heterocyclic aromatic hydrocarbons with a relative molecular mass of 400–4000, possessing a certain degree of planarity and regular arrangement. It exhibits both crystalline optical anisotropy and exists in a fluid state. The materials for preparing mesophase pitch are widely available and inexpensive, making it an excellent precursor for producing high-performance carbon materials such as carbon fibers, carbon foam, C / C composites, high thermal conductivity carbon, and carbon electrodes. Carbon fibers prepared from mesophase pitch possess high modulus, high strength, good thermal conductivity, good heat resistance, and corrosion resistance, and can be used in aircraft material manufacturing, track design, and are also widely applied in the production of golf clubs, tennis rackets, fishing gear, and other materials. Currently, the production scale of mesophase pitch remains low, especially achieving a complete production line of thousands of tons, which is difficult. It is necessary to solve the current problem of not being able to continuously produce high-purity mesophase pitch and thus not being able to reduce the cost of large-scale production. Moreover, how to further improve the quality of mesophase pitch is a topic that requires further research in this field.

[0004] Heavy crude oil rich in aromatics, catalytic slurry oil from secondary processed oils, and ethylene tar are theoretically ideal raw materials for the production of carbon materials. However, due to the high content of polycyclic aromatic hydrocarbons and impurities such as sulfur, nitrogen, metals, and ash in these raw materials, there is currently a lack of representative and efficient processing and utilization technologies.

[0005] In crude oil processing, the main technologies for heavy oil conversion include catalytic cracking, hydrotreating, and coking. Heavy oil hydrotreating is a process technology that simultaneously meets the requirements of efficient heavy oil utilization and environmental protection. To date, four process types have been developed for heavy oil hydrotreating: fixed bed, fluidized bed, slurry bed, and moving bed. Among these four types, the fixed bed process is mature, easy to operate, and has relatively low investment costs, making it the most widely used. The main reactions occurring during heavy oil hydrotreating include hydrodemetallization, hydrodesulfurization, hydronitrogenation, residual carbon conversion, and hydrocracking of asphaltenes.

[0006] CN103184057A, CN104560152A and other publications disclose methods for producing needle coke using catalytic oil slurry as raw material. However, needle coke has high requirements for raw materials, and not all components in catalytic oil slurry can be used to produce needle coke.

[0007] CN1872963A discloses a method for producing needle coke feedstock, which enriches tricyclic and tetracyclic aromatic hydrocarbons in catalytic oil slurry as feedstock for producing needle coke, but the remaining components are still not well utilized.

[0008] CN101250433A discloses a coal tar hydrogenation process. Coal tar is pretreated to obtain coal tar hydrogenation feedstock, which then passes through a series of upflow pre-hydrogenation fixed-bed reactors and downflow main hydrogenation fixed-bed reactors. The process involves fractionation to obtain gasoline, diesel, and light fuel oil fractions. The purpose of this process is to produce fuel oil, but the gas-liquid mass transfer in the reaction system is poor, and the investment is high.

[0009] CN103789028A discloses a pretreatment method for producing needle coke feedstock from catalytic oil slurry, comprising: filtering the catalytic oil slurry and then subjecting it to mild hydrogenation treatment; sending 20% ​​to 50% (by weight) of the hydrogenated oil to a vacuum distillation unit; and mixing the resulting hydrogenated light distillate with the remaining hydrogenated oil as feedstock for needle coke production. However, this method has poor feedstock adaptability, low oil slurry yield, and low utilization rate.

[0010] CN117683562A discloses a method and system for preparing feedstock for needle coke production. The method includes: mixing feedstock oil and an oil-soluble hydrogenation catalyst to obtain feed oil; then feeding the feed oil into a slurry-bed hydrogenation reactor to contact with hydrogen and selectively hydrogenate it to obtain a hydrogenated product; subjecting the hydrogenated product to a first separation to obtain a first separation product and a second separation product; the first separation product contains naphtha, hydrogen, and light oil gas; the second separation product contains heavy oil slurry and an oil-soluble hydrogenation catalyst; subjecting the second separation product to vacuum distillation to obtain atmospheric distillate oil, vacuum distillate oil, and recycled tail oil; returning the recycled tail oil and mixing it with the feedstock oil and the oil-soluble hydrogenation catalyst for reuse. This method reduces the impurity content in the vacuum distillate oil and increases the content of tricyclic and tetracyclic aromatics. However, this method has drawbacks such as low impurity removal rate, high conversion rate, low yield of effective carbon materials, and low quality of the produced carbon materials.

[0011] Therefore, how to further improve the adaptability of carbon material raw materials and improve the quality of carbon materials such as needle coke and mesophase pitch are topics that need further research in this field. Summary of the Invention

[0012] To address at least one of the aforementioned technical problems, the present invention aims to provide a method and system for preparing carbon material feedstocks via staged hydrogenation of heavy oil. The carbon material feedstocks prepared by the present invention exhibit high yields, high contents of tricyclic and tetracyclic aromatic hydrocarbons, and low impurity content, and can be used to prepare high-quality carbon materials.

[0013] To achieve the above objectives, the first aspect of the present invention provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, comprising the following steps:

[0014] (1) The heavy oil is pretreated to obtain the pretreated product;

[0015] (2) The pretreated product obtained in step (1) is subjected to hydrogenation pretreatment to obtain the hydrogenated pretreated product.

[0016] (3) The product obtained after hydrogenation pretreatment in step (2) is subjected to vacuum distillation to obtain light distillate oil, middle distillate oil and heavy distillate oil;

[0017] (4) Selectively hydrogenate the middle distillate oil obtained in step (3) to obtain the product after selective hydrogenation.

[0018] (5) The heavy distillate oil obtained in step (3) is subjected to hydroring ring-opening treatment to obtain the product after hydroring ring-opening treatment;

[0019] (6) The product obtained in step (4) after selective hydrogenation and the product obtained in step (5) after hydrogenation ring-opening treatment are post-processed to obtain the carbon material raw material.

[0020] According to a specific embodiment of the present invention, preferably, in step (1), based on the total mass of the heavy oil as 100%, the sulfur content of the heavy oil is 0.5-5.0%, the asphaltene content is 1-15%, the effective aromatic hydrocarbon content is 15-50%; and the nitrogen content of the heavy oil is 900-9000 μg / g, and the ash content is 800-7000 ppm.

[0021] According to a specific embodiment of the present invention, preferably, in step (1), the pretreatment includes desolidification, and the desolidification method includes one or more of the following: filtration, sedimentation and electrostatic separation.

[0022] According to a specific embodiment of the present invention, preferably, in step (1), the ash content in the pretreated product is less than 100 ppm.

[0023] According to a specific embodiment of the present invention, preferably, in step (2), the conditions for the hydrogenation pretreatment include: a hydrogen partial pressure of 0.5-35.0 MPa, a temperature of 250-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000. More preferably, the conditions for the hydrogenation pretreatment include: a hydrogen partial pressure of 4.0-20.0 MPa, a temperature of 350-450 °C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800.

[0024] According to a specific embodiment of the present invention, preferably, in step (2), after the hydrogenation pretreatment, gas-liquid separation is further performed, and the liquid phase product obtained by the gas-liquid separation is the product after the hydrogenation pretreatment.

[0025] According to a specific embodiment of the present invention, preferably, in step (3), the 10% distillation point temperature of the light distillate oil is 150-250℃, and the 90% distillation point is 300-400℃; the 10% distillation point of the middle distillate oil is 310-390℃, and the 90% distillation point is 380-520℃; the 10% distillation point of the heavy distillate oil is 460-550℃. More preferably, the 10% distillation point temperature of the light distillate oil is 200-230℃, and the 90% distillation point is 330-360℃; the 10% distillation point of the middle distillate oil is 320-370℃, and the 90% distillation point is 400-500℃; the 10% distillation point of the heavy distillate oil is 460-520℃.

[0026] According to a specific embodiment of the present invention, preferably, in step (4), the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 1.0-35.0 MPa, a temperature of 280-500 °C, and a volume hourly space velocity of 0.5-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000. More preferably, the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 4.0-10.0 MPa, a temperature of 300-450°C, and a volume hourly space velocity of 0.8-1.2 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800.

[0027] According to a specific embodiment of the present invention, preferably, in step (5), the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 5.0-35.0 MPa, a temperature of 320-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 500-1500. More preferably, the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 8.0-20.0 MPa, a temperature of 350-450 °C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 600-1200.

[0028] According to a specific embodiment of the present invention, preferably, in step (6), the post-processing includes gas-liquid separation, wherein the liquid phase product obtained by gas-liquid separation is the carbon material raw material.

[0029] According to a specific embodiment of the present invention, preferably, in step (6), based on the total mass of the carbon material raw material as 100%, the effective aromatic hydrocarbon content of the carbon material raw material is 35-60%, the sulfur content is 0.05-0.15%, the asphaltene content is 0.2-1.5%, and the nitrogen content of the carbon material raw material is 500-3000 μg / g.

[0030] A second aspect of the present invention provides a system for preparing carbon material feedstock by staged hydrogenation of heavy oil. The system is used to implement the aforementioned method for preparing carbon material feedstock by staged hydrogenation of heavy oil. The system includes: a pretreatment device, a hydrogenation pretreatment reactor, a vacuum distillation device, a selective hydrogenation reactor, a hydrogenation ring-opening reactor, and a post-treatment device. The pretreatment device is sequentially connected to the hydrogenation pretreatment reactor and the vacuum distillation device. The vacuum distillation device is provided with a light distillate oil outlet, a middle distillate oil outlet, and a heavy distillate oil outlet. The middle distillate oil outlet is connected to the selective hydrogenation reactor, the heavy distillate oil outlet is connected to the hydrogenation ring-opening reactor, and the selective hydrogenation reactor and the hydrogenation ring-opening reactor are connected to the post-treatment device.

[0031] According to a specific embodiment of the present invention, preferably, the pretreatment device includes a desolidification device, which includes one or more of the following: a metal mesh filter, a centrifuge, a flocculation sedimentation device, a high-voltage electric field packed tower, and an inorganic ceramic membrane filter.

[0032] According to a specific embodiment of the present invention, preferably, the system further includes a first gas-liquid separation device, the first gas-liquid separation device having at least an inlet, a gas phase outlet and a liquid phase outlet, the inlet of the first gas-liquid separation device being connected to the product outlet of the hydrogenation pretreatment reactor, and the liquid phase outlet of the first gas-liquid separation device being connected to the inlet of the vacuum distillation device.

[0033] According to a specific embodiment of the present invention, preferably, the hydrogenation pretreatment reactor, the selective hydrogenation treatment reactor, and the hydrogenation ring-opening treatment reactor each include one or more of the following: a fixed-bed reactor, a suspended-bed reactor, a fluidized-bed reactor, and a moving-bed reactor.

[0034] According to a specific embodiment of the present invention, preferably, the vacuum distillation apparatus includes one or two of the following: a stripping tower and a fractionating tower.

[0035] According to a specific embodiment of the present invention, preferably, the post-processing device includes a second gas-liquid separation device, the second gas-liquid separation device having at least an inlet, a gas phase outlet and a liquid phase outlet, the carbon material raw material flowing out of the liquid phase outlet of the second gas-liquid separation device.

[0036] The present invention has at least the following beneficial effects:

[0037] This invention performs hydrotreating pretreatment on pre-treated heavy oil, improving its stability while moderately converting asphaltenes. The pre-treated product is then subjected to vacuum distillation, followed by selective hydrotreating and hydrogenation ring-opening treatment on the separated middle and heavy distillate fractions, respectively. This separate hydrotreating for different fractions increases the flexibility of the invention, improves its adaptability to heavy oil feedstocks, and increases the yield of carbon material feedstocks. Furthermore, this invention fully utilizes the heavy distillate fraction, deeply removing impurities such as sulfur and nitrogen while simultaneously increasing the yield of carbon material feedstocks and the content of tricyclic and tetracyclic aromatic hydrocarbons through polycyclic aromatic hydrocarbon cracking. The products after selective hydrotreating and hydrogenation ring-opening treatment are then post-treated to obtain the carbon material feedstocks of this invention. This method broadens the range of feedstocks for preparing high-quality carbon materials, efficiently removing impurities from heavy oil while inhibiting oversaturation of aromatic hydrocarbons and increasing the content of tricyclic and tetracyclic aromatic hydrocarbons, while simultaneously reducing costs. The carbon material raw materials prepared by this invention have a high yield, a high content of tricyclic and tetracyclic aromatic hydrocarbons and a low impurity content. They can be used to prepare high-quality carbon materials, such as needle coke and / or mesophase pitch, and in particular, can co-produce high-quality needle coke and mesophase pitch. Attached Figure Description

[0038] Figure 1 is a schematic diagram of the method and system for preparing carbon material raw materials by staged hydrogenation of heavy oil in a specific embodiment of the present invention.

[0039] Explanation of icon numbers:

[0040] 1-Desolidification device; 2-Hydrogenation pretreatment reactor; 3-First gas-liquid separation device; 4-Vacuum distillation device; 5-Selective hydrogenation treatment reactor; 6-Hydrogenation ring-opening treatment reactor; 7-Second gas-liquid separation device. Detailed Implementation

[0041] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the present invention will now be described in detail below, but this should not be construed as limiting the scope of the invention.

[0042] It should be noted that, unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0044] In the description of this invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] According to a specific embodiment of the first aspect of the present invention, as shown in FIG1, the present invention provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, which includes the following steps:

[0046] (1) The heavy oil is desolidified in the desolidification device 1 to obtain the desolidified product;

[0047] (2) The product obtained after desolidification in step (1) is subjected to hydrogenation pretreatment in hydrogenation pretreatment reactor 2, and then separated into gas and liquid by first gas-liquid separation device 3 to obtain the liquid phase product after hydrogenation pretreatment.

[0048] (3) The liquid phase product after hydrogenation pretreatment obtained in step (2) is subjected to vacuum distillation in vacuum distillation apparatus 4 to obtain light distillate oil, middle distillate oil and heavy distillate oil.

[0049] (4) The middle distillate oil obtained in step (3) is selectively hydrogenated in the selective hydrogenation reactor 5 to obtain the product after selective hydrogenation.

[0050] (5) The heavy distillate oil obtained in step (3) is subjected to hydroring-ring-opening treatment in hydroring-opening treatment reactor 6 to obtain the hydroring-ring-opening product.

[0051] (6) The product obtained in step (4) after selective hydrogenation treatment and the product obtained in step (5) after hydrogenation ring-opening treatment are separated into gas and liquid phases by the second gas-liquid separation device 7. The resulting liquid phase is the carbon material raw material.

[0052] In some embodiments, in step (1), based on the total mass of the heavy oil as 100%, the heavy oil has a sulfur content of 0.5-5.0%, an asphaltene content of 1-15%, and an effective aromatic hydrocarbon content of 15-50%; and the heavy oil has a nitrogen content of 900-9000 μg / g and an ash content of 800-7000 ppm. Specifically, the heavy oil may include one or more of the following: catalytic slurry oil, residual oil, furfural extract oil, ethylene tar, coal tar, and coal-based soft pitch. This invention has a wide adaptability to heavy oil feedstocks, and can use petroleum-based feedstocks, coal-based feedstocks, or a mixture of one or more of petroleum-based and coal-based feedstocks. Those skilled in the art will understand that ash refers to the non-flammable substances remaining after the oil has been calcined at high temperatures, and is generally inorganic.

[0053] In this invention, effective aromatic hydrocarbons refer to tricyclic aromatic hydrocarbons and tetracyclic aromatic hydrocarbons.

[0054] In some embodiments, in step (1), the desolidification method includes one or more of the following: filtration, sedimentation and electrostatic separation.

[0055] In some embodiments, in step (1), the ash content of the deconsolidated product is less than 100 ppm.

[0056] In some embodiments, in step (2), the conditions for the hydrogenation pretreatment include: a hydrogen partial pressure of 0.5-35.0 MPa, a temperature of 250-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000. Preferably, the conditions for the hydrotreating pretreatment include: a hydrogen partial pressure of 4.0-20.0 MPa, a temperature of 350-450°C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800. In this invention, the hydrogen-to-oil ratio refers to the hydrogen-to-oil volume ratio.

[0057] In some embodiments, in step (3), the 10% distillation point temperature of the light distillate oil is 150-250℃, and the 90% distillation point is 300-400℃; the 10% distillation point of the middle distillate oil is 310-390℃, and the 90% distillation point is 380-520℃; the 10% distillation point of the heavy distillate oil is 460-550℃. Preferably, the 10% distillation point temperature of the light distillate oil is 200-230℃, and the 90% distillation point is 330-360℃; the 10% distillation point of the middle distillate oil is 320-370℃ (more preferably 340-380℃), and the 90% distillation point is 400-500℃ (more preferably 440-480℃); the 10% distillation point of the heavy distillate oil is 460-520℃.

[0058] In some embodiments, in step (4), the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 1.0-35.0 MPa, a temperature of 280-500 °C, and a volume hourly space velocity of 0.5-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000. Preferably, the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 1.0-10.0 MPa, more preferably 4.0-10.0 MPa, a temperature of 300-450°C, and a volume hourly space velocity of 0.8-1.2 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800.

[0059] In some embodiments, in step (5), the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 5.0-35.0 MPa, a temperature of 320-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 500-1500. Preferably, the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 8.0-20.0 MPa, a temperature of 350-450°C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 600-1200.

[0060] In embodiments of the present invention, the hydrogenation pretreatment, the selective hydrogenation treatment, and the hydrogenation ring-opening treatment all require the use of a hydrogenation catalyst. The present invention does not impose special limitations on the hydrogenation catalyst and can employ hydrogenation catalysts from the prior art. For example, the hydrogenation catalyst used may include one or more catalysts selected from hydrogenation protectants, hydrogenation pretreatment agents, hydrogenation desulfurizers, hydrogenation denitrifiers, hydrogenation demetallizers, and hydrogenation ring-opening catalysts, or a combination of two or more such catalysts. Generally, the hydrogenation catalyst includes a support and a metal oxide active component supported on the support. The support may include one or more porous, refractory compounds, such as alumina, clay, and molecular sieves; or the support may also be a porous, refractory compound containing one or more of elements such as P, Si, F, and B. The metal oxide active component may include one or more metal oxides selected from Group VIB and Group VIII metals, such as one or more metal oxides selected from W, Mo, Co, and Ni.

[0061] In some preferred embodiments, the hydrogenation catalyst used in the hydrogenation pretreatment includes a hydrogenation protectant and a hydrogenation pretreatment agent; the hydrogenation catalyst used in the selective hydrogenation treatment includes a hydrogenation protectant and a hydrogenation desulfurizer, and selectively includes one or both of a hydrogenation denitrification agent and a hydrogenation demetallization agent; the hydrogenation catalyst used in the hydrogenation ring-opening treatment includes a hydrogenation protectant, a hydrogenation demetallization agent, and a hydrogenation ring-opening catalyst, and selectively includes a hydrogenation denitrification agent. Specifically, the hydrogenation catalyst used in the hydrogenation pretreatment includes a hydrogenation protectant and a hydrogenation pretreatment agent loaded sequentially along the stream direction. The hydrogenation catalyst used in the selective hydrogenation treatment includes a hydrogenation protectant and a hydrogenation desulfurizer loaded sequentially along the stream direction, or includes a hydrogenation protectant, a hydrogenation desulfurizer, and a hydrogenation denitrification agent loaded sequentially along the stream direction, or includes a hydrogenation protectant, a hydrogenation demetallization agent, and a hydrogenation desulfurizer loaded sequentially along the stream direction. The hydrogenation catalyst used in the hydrogenation ring-opening process includes a hydrogenation protectant, a hydrogenation demetallizing agent, and a hydrogenation ring-opening catalyst loaded sequentially along the stream flow direction, or includes a hydrogenation protectant, a hydrogenation demetallizing agent, a hydrogenation denitrifying agent, and a hydrogenation ring-opening catalyst loaded sequentially along the stream flow direction.

[0062] In some embodiments, in step (6), based on the total mass of the carbon material raw material as 100%, the effective aromatic hydrocarbon content of the carbon material raw material is 35-60%, the sulfur content is 0.05-0.15%, the asphaltene content is 0.2-1.5%, and the nitrogen content of the carbon material raw material is 500-3000 μg / g.

[0063] According to a specific embodiment of the second aspect of the present invention, the present invention provides a system for preparing carbon material raw materials by staged hydrogenation of heavy oil. The system is used to realize the above-mentioned method for preparing carbon material raw materials by staged hydrogenation of heavy oil. As shown in FIG1, the system includes: a desolidification device 1, a hydrogenation pretreatment reactor 2, a first gas-liquid separation device 3, a vacuum distillation device 4, a selective hydrogenation treatment reactor 5, a hydrogenation ring-opening treatment reactor 6, and a second gas-liquid separation device 7.

[0064] Among them, the solidification device 1 is provided with at least an inlet and an outlet, the hydrotreating pretreatment reactor 2 is provided with at least a raw material inlet, a hydrogen inlet and a product outlet, the first gas-liquid separation device 3 is provided with at least an inlet, a gas phase outlet and a liquid phase outlet, the vacuum distillation device 4 is provided with at least an inlet, a light distillate oil outlet, a middle distillate oil outlet and a heavy distillate oil outlet, the selective hydrotreating reactor 5 is provided with at least a raw material inlet, a hydrogen inlet and a product outlet, the hydrotreating ring-opening treatment reactor 6 is provided with at least a raw material inlet, a hydrogen inlet and a product outlet, and the second gas-liquid separation device 7 is provided with at least an inlet, a gas phase outlet and a liquid phase outlet;

[0065] The outlet of the desolidification unit 1 is connected to the feed inlet of the hydrotreating pretreatment reactor 2. The product outlet of the hydrotreating pretreatment reactor 2 is connected to the inlet of the first gas-liquid separation unit 3. The liquid phase outlet of the first gas-liquid separation unit 3 is connected to the inlet of the vacuum distillation unit 4. The middle distillate oil outlet of the vacuum distillation unit 4 is connected to the feed inlet of the selective hydrotreating reactor 5. The heavy distillate oil outlet of the vacuum distillation unit 4 is connected to the feed inlet of the hydroopen-loop treatment reactor 6. The product outlets of the selective hydrotreating reactor 5 and the hydroopen-loop treatment reactor 6 are connected to the inlet of the second gas-liquid separation unit 7. The carbon material feedstock flows out from the liquid phase outlet of the second gas-liquid separation unit 7.

[0066] In some embodiments, the desolidification device 1 includes one or more of the following: a metal mesh filter, a centrifuge, a flocculation sedimentation device, a high-voltage electric field packed tower, and an inorganic ceramic membrane filter.

[0067] In some embodiments, the hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation ring-opening treatment reactor 6 each include one or more of the following: a fixed-bed reactor, a suspended-bed reactor, a fluidized-bed reactor, and a moving-bed reactor, with a fixed-bed reactor being preferred. Specifically, the hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation ring-opening treatment reactor 6 may each include one reactor, or they may each include multiple reactors connected in series.

[0068] In some embodiments, the first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators, which may specifically include one or two of high-pressure gas-liquid separators and low-pressure gas-liquid separators.

[0069] In some embodiments, the vacuum distillation apparatus 4 includes one or two of the following: a stripping column and a fractionating column.

[0070] In the embodiments of the present invention, after the carbon material raw material is prepared by the above method and system, the carbon material can then be prepared by the process in the prior art. The carbon material includes needle coke and / or mesophase pitch, etc.

[0071] In some embodiments, the preparation of needle coke using the carbon material raw material of the present invention involves reacting the carbon material raw material in a coking reaction zone to obtain needle coke. The coking reaction zone generally includes at least one heating furnace and at least two coke towers, and at least one coke tower is always in the reaction stage and at least one coke tower is in the decoking stage. The reaction conditions in the coking reaction zone may include: a heating furnace outlet temperature of 410-550°C, preferably 440-520°C; a heating rate of 0.5-30°C / h, preferably 3-8°C / h; a tower top pressure of 0.01-2.5 MPa, preferably 0.2-1.3 MPa; the coke tower can operate under constant pressure or variable pressure; when operating under variable pressure, the variable pressure rate is 0.1-5 MPa / h; and the reaction cycle of the coking reaction zone is 10-72 hours, preferably 32-54 hours. The specific devices in the coking reaction zone can be those commonly used in the art, and those skilled in the art can select or adjust them according to actual conditions.

[0072] In other embodiments, the preparation of mesophase pitch using the carbon material raw material of the present invention involves sequentially subjecting the carbon material raw material to a polymerization reaction and an oxidation reaction to obtain the mesophase pitch. Specifically, the polymerization reaction is carried out at a temperature of 360-440°C, a pressure of 2.0-8.0 MPa, and a time of 1-10 h; the oxidation reaction is carried out at a temperature of 280-330°C, a time of 1-6 h, and an air flow rate of 1-2 L / min. The specific apparatus used for the polymerization and oxidation reactions can be commonly used in the art, and those skilled in the art can select or adjust it according to the actual situation.

[0073] The present invention is illustrated in detail below by way of examples, but the present invention is not limited to these examples. Of course, various modifications can be made within the scope of the present invention.

[0074] The sources of heavy oil feedstock and hydrogenation catalyst used in the following examples and comparative examples are shown in Table 1.

[0075] Table 1. Sources of heavy oil feedstock and hydrotreating catalysts

[0076] Example 1

[0077] This embodiment provides a method for preparing carbon material feedstocks by staged hydrogenation of heavy oil, which includes the following steps:

[0078] (1) The heavy oil is desolidified in the desolidification device 1 to obtain the desolidified product;

[0079] (2) The product obtained after desolidification in step (1) is subjected to hydrogenation pretreatment in hydrogenation pretreatment reactor 2, and then separated into gas and liquid by first gas-liquid separation device 3 to obtain the liquid phase product after hydrogenation pretreatment.

[0080] (3) The liquid phase product after hydrogenation pretreatment obtained in step (2) is subjected to vacuum distillation in vacuum distillation apparatus 4 to obtain light distillate oil, middle distillate oil and heavy distillate oil.

[0081] (4) The middle distillate oil obtained in step (3) is selectively hydrogenated in the selective hydrogenation reactor 5 to obtain the product after selective hydrogenation.

[0082] (5) The heavy distillate oil obtained in step (3) is subjected to hydroring-ring-opening treatment in hydroring-opening treatment reactor 6 to obtain the hydroring-ring-opening product.

[0083] (6) The product obtained in step (4) after selective hydrogenation treatment and the product obtained in step (5) after hydrogenation ring-opening treatment are separated into gas and liquid phases by the second gas-liquid separation device 7. The resulting liquid phase is the carbon material raw material.

[0084] The main properties of the heavy oil used in this embodiment are shown in Table 2.

[0085] In this embodiment, in step (1), the deconsolidation method is filtration. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 155℃, and the 90% distillation point is 340℃; the 10% distillation point of the middle distillate oil is 325℃, and the 90% distillation point is 470℃; the 10% distillation point of the heavy distillate oil is 490℃. In step (4), the conditions for the selective hydrogenation treatment are shown in Table 4. In step (5), the conditions for the hydrogenation ring-opening treatment are shown in Table 5.

[0086] In this embodiment, the desolidification device 1 is a metal mesh filter. The hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation open-loop treatment reactor 6 are all fixed-bed reactors. The first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators. The vacuum distillation device 4 is a fractionation column.

[0087] The hydrotreating pretreatment reactor 2 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404 and hydropretreatment agent PHR-201 loaded sequentially along the stream direction at a volume ratio of 40:60. The selective hydrotreating reactor 5 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404, hydrodesulfurizing agent PHR-202, and hydrodenitrifying agent PHR-301 loaded sequentially along the stream direction at a volume ratio of 20:50:30. The hydroring-opening reactor 6 consists of two fixed-bed reactors, specifically two trickle-bed reactors connected in series, with hydroprotective agent PHR-404, hydrodemetallizing agent PHR-103, and hydroring-opening catalyst PHR-302 loaded sequentially along the stream direction at a volume ratio of 20:20:60.

[0088] The main properties of the carbon material raw materials prepared in this embodiment are shown in Table 6.

[0089] Example 2

[0090] This embodiment provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, which includes the same steps as the method in Embodiment 1.

[0091] The main properties of the heavy oil used in this embodiment are shown in Table 2.

[0092] In this embodiment, in step (1), the deconsolidation method is filtration. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 221℃, and the 90% distillation point is 353℃; the 10% distillation point of the middle distillate oil is 340℃, and the 90% distillation point is 482℃; the 10% distillation point of the heavy distillate oil is 470℃. In step (4), the conditions for the selective hydrogenation treatment are shown in Table 4. In step (5), the conditions for the hydrogenation ring-opening treatment are shown in Table 5.

[0093] In this embodiment, the desolidification device 1 is an inorganic ceramic membrane filter. The hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation ring-opening treatment reactor 6 are all fixed-bed reactors. The first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators. The vacuum distillation device 4 is a fractionation column.

[0094] Hydrotreating pretreatment reactor 2 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydrotreating protectant PHR-404 and hydrotreating pretreatment agent PHR-201 loaded sequentially along the stream direction at a volume ratio of 70:30. Selective hydrotreating reactor 5 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydrotreating protectant PHR-404 and hydrodesulfurizing agent PHR-202 loaded sequentially along the stream direction at a volume ratio of 30:70. Hydrotreating ring-opening reactor 6 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydrotreating protectant PHR-404, hydrodemetallizing agent PHR-103, hydrodenitrifying agent PHR-301, and hydrorecycling ring-opening catalyst PHR-302 loaded along the stream direction at a volume ratio of 15:15:20:50.

[0095] The main properties of the carbon material raw materials prepared in this embodiment are shown in Table 6.

[0096] Example 3

[0097] This embodiment provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, which includes the same steps as the method in Embodiment 1.

[0098] The main properties of the heavy oil used in this embodiment are shown in Table 2.

[0099] In this embodiment, in step (1), the deconsolidation method is electrostatic separation. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 237℃, and the 90% distillation point is 347℃; the 10% distillation point of the middle distillate oil is 352℃, and the 90% distillation point is 491℃; the 10% distillation point of the heavy distillate oil is 488℃. In step (4), the conditions for the selective hydrogenation treatment are shown in Table 4. In step (5), the conditions for the hydrogenation ring-opening treatment are shown in Table 5.

[0100] In this embodiment, the desolidification device 1 is a high-voltage electric field packed tower. The hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation ring-opening treatment reactor 6 are all fixed-bed reactors. The first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators. The vacuum distillation device 4 is a fractionation tower.

[0101] The hydrotreating pretreatment reactor 2 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404 and hydropretreatment agent PHR-201 loaded sequentially along the stream direction at a volume ratio of 35:65. The selective hydrotreating reactor 5 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404 and hydrodesulfurizing agent PHR-202 loaded sequentially along the stream direction at a volume ratio of 45:55. The hydroring-opening reactor 6 consists of two fixed-bed reactors, specifically two trickle-bed reactors connected in series, with hydroprotective agent PHR-404, hydrodemetallizing agent PHR-103, hydrodenitrifying agent PHR-301, and hydroring-opening catalyst PHR-302 loaded sequentially along the stream direction at a volume ratio of 15:15:10:60.

[0102] The main properties of the carbon material raw materials prepared in this embodiment are shown in Table 6.

[0103] Example 4

[0104] This embodiment provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, which includes the same steps as the method in Embodiment 1.

[0105] The main properties of the heavy oil used in this embodiment are shown in Table 2.

[0106] In this embodiment, in step (1), the deconsolidation method is a combination of sedimentation and filtration. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 213℃, and the 90% distillation point is 357℃; the 10% distillation point of the middle distillate oil is 363℃, and the 90% distillation point is 497℃; the 10% distillation point of the heavy distillate oil is 498℃. In step (4), the conditions for the selective hydrogenation treatment are shown in Table 4. In step (5), the conditions for the hydrogenation ring-opening treatment are shown in Table 5.

[0107] In this embodiment, the desolidification device 1 is a flocculation sedimentation device and a metal screen filter. The hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation open-loop treatment reactor 6 are all fixed-bed reactors. The first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators. The vacuum distillation device 4 is a fractionation tower.

[0108] The hydrotreating pretreatment reactor 2 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404 and hydropretreatment agent PHR-201 loaded sequentially along the stream direction at a volume ratio of 30:70. The selective hydrotreating reactor 5 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydroprotective agent PHR-404, hydrodesulfurizing agent PHR-202, and hydrodenitrifying agent PHR-301 loaded sequentially along the stream direction at a volume ratio of 30:10:60. The hydroring-opening reactor 6 consists of two fixed-bed reactors, specifically two trickle-bed reactors connected in series, with hydroprotective agent PHR-404, hydrodemetallizing agent PHR-103, hydrodenitrifying agent PHR-301, and hydroring-opening catalyst PHR-302 loaded sequentially along the stream direction at a volume ratio of 10:20:15:55.

[0109] The main properties of the carbon material raw materials prepared in this embodiment are shown in Table 6.

[0110] Example 5

[0111] This embodiment provides a method for preparing carbon material feedstock by staged hydrogenation of heavy oil, which includes the same steps as the method in Embodiment 1.

[0112] The main properties of the heavy oil used in this embodiment are shown in Table 2.

[0113] In this embodiment, in step (1), the deconsolidation method is filtration. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 203℃, and the 90% distillation point is 355℃; the 10% distillation point of the middle distillate oil is 362℃, and the 90% distillation point is 486℃; the 10% distillation point of the heavy distillate oil is 505℃. In step (4), the conditions for the selective hydrogenation treatment are shown in Table 4. In step (5), the conditions for the hydrogenation ring-opening treatment are shown in Table 5.

[0114] In this embodiment, the desolidification device 1 is an inorganic ceramic membrane filter. The hydrogenation pretreatment reactor 2, the selective hydrogenation treatment reactor 5, and the hydrogenation ring-opening treatment reactor 6 are all fixed-bed reactors. The first gas-liquid separation device 3 and the second gas-liquid separation device 7 are gas-liquid separators. The vacuum distillation device 4 is a fractionation column.

[0115] The hydrotreating pretreatment reactor 2 consists of a fixed-bed reactor, specifically a trickle-bed reactor, with hydrotreating protectant PHR-404 and hydrotreating pretreatment agent PHR-201 loaded sequentially along the stream direction at a volume ratio of 60:40. The selective hydrotreating reactor 5 consists of two fixed-bed reactors, specifically two trickle-bed reactors connected in series, with hydrotreating protectant PHR-404, hydrodemetallizing agent PHR-103, and hydrodesulfurizing agent PHR-202 loaded sequentially along the stream direction at a volume ratio of 40:40:20. The hydroring-opening reactor 6 consists of three fixed-bed reactors, specifically three trickle-bed reactors connected in series, with hydrotreating protectant PHR-404, hydrodemetallizing agent PHR-103, hydrodenitrifying agent PHR-301, and hydroring-opening catalyst PHR-302 loaded sequentially along the stream direction at a volume ratio of 10:10:10:70.

[0116] The main properties of the carbon material raw materials prepared in this embodiment are shown in Table 6.

[0117] Comparative Example 1

[0118] This comparative example provides a method for preparing carbon material raw materials, which includes the following steps:

[0119] (1) The heavy oil is desolidified in a desolidification device to obtain the desolidified product;

[0120] (2) The desolidified product obtained in step (1) is subjected to hydrogenation ring-opening treatment in a hydrogenation ring-opening treatment reactor to obtain the hydrogenation ring-opening treatment product.

[0121] (3) The product obtained after hydrogenation ring-opening treatment in step (2) is separated into gas and liquid phases by a gas-liquid separator, and the resulting liquid phase is the carbon material raw material.

[0122] The heavy oil used in this comparative example is the same as that in Example 1, and its main properties are shown in Table 2.

[0123] In this comparative example, the deconsolidation method in step (1) is the same as in Example 1. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation ring-opening treatment are the same as in Example 1, as shown in Table 5.

[0124] In this comparative example, the solidification apparatus is the same as in Example 1. The hydrocracking ring-opening reactor consists of two fixed-bed reactors, specifically two trickle-bed reactors connected in series. Along the stream flow direction, the reactors are sequentially loaded with a volume ratio of 20:20:20:20:20:20 for the following components: hydroprotectant PHR-404, hydrodemetallizer PHR-103, hydrodesulfurizer PHR-202, hydrodenitrogenator PHR-301, and hydrocracking ring-opening catalyst PHR-302. The gas-liquid separator is the same as in Example 1.

[0125] The main properties of the carbon material raw materials prepared in this comparative example are shown in Table 6.

[0126] Comparative Example 2

[0127] This comparative example provides a method for preparing carbon material raw materials, which includes the following steps:

[0128] (1) The heavy oil is desolidified in a desolidification device to obtain the desolidified product;

[0129] (2) The desolidified product obtained in step (1) is subjected to vacuum distillation in a vacuum distillation apparatus to obtain light distillate oil, middle distillate oil and heavy distillate oil.

[0130] (3) The middle distillate oil obtained in step (2) is selectively hydrogenated in a selective hydrogenation reactor to obtain the product after selective hydrogenation.

[0131] (4) The heavy distillate oil obtained in step (3) is subjected to hydroring-ring-opening treatment in a hydroring-ring-opening treatment reactor to obtain the hydroring-ring-opening product.

[0132] (5) The product obtained in step (3) after selective hydrogenation treatment and the product obtained in step (4) after hydrogenation ring-opening treatment are separated by a gas-liquid separator, and the resulting liquid phase is the carbon material raw material.

[0133] The heavy oil used in this comparative example is the same as that in Example 2, and its main properties are shown in Table 2.

[0134] In this comparative example, the deconsolidation method in step (1) is the same as in Example 1. The ash content of the deconsolidated product is below 100 ppm. In step (2), the 10% distillation point temperature of the light distillate oil is 210°C, and the 90% distillation point is 341°C; the 10% distillation point temperature of the middle distillate oil is 331°C, and the 90% distillation point is 473°C; the 10% distillation point temperature of the heavy distillate oil is 460°C; all these conditions are similar to those in Example 2. In step (3), the selective hydrogenation treatment conditions are the same as in Example 2, as shown in Table 4. In step (4), the hydrogenation ring-opening treatment conditions are the same as in Example 2, as shown in Table 5.

[0135] In this comparative example, the desolidification apparatus is the same as in Example 2. The vacuum distillation apparatus is the same as in Example 2. The selective hydrogenation reactor and the hydrogenation ring-opening reactor, as well as the hydrogenation catalyst packed therein, are the same as in Example 2. The gas-liquid separator is the same as in Example 2.

[0136] The main properties of the carbon material raw materials prepared in this comparative example are shown in Table 6.

[0137] Comparative Example 3

[0138] This comparative example provides a method for preparing carbon material raw materials, which includes the following steps:

[0139] (1) The heavy oil is desolidified in a desolidification device to obtain the desolidified product;

[0140] (2) The product obtained after desolidification in step (1) is subjected to hydrogenation pretreatment in a hydrogenation pretreatment reactor, and then separated into gas and liquid phases by a first gas-liquid separation device to obtain the liquid phase product after hydrogenation pretreatment.

[0141] (3) The liquid phase product after hydrogenation pretreatment obtained in step (2) is subjected to vacuum distillation in a vacuum distillation apparatus to obtain light distillate oil, middle distillate oil and heavy distillate oil.

[0142] (4) After mixing the middle distillate oil and heavy distillate oil obtained in step (3), selective hydrogenation is carried out in a selective hydrogenation reactor to obtain the product after selective hydrogenation.

[0143] (5) After selective hydrogenation treatment of the product obtained in step (4), the product is separated into gas and liquid phase by a second gas-liquid separation device, and the resulting liquid phase is the carbon material raw material.

[0144] The heavy oil used in this comparative example is the same as that in Example 1, and its main properties are shown in Table 2.

[0145] In this comparative example, the deconsolidation method in step (1) is the same as in Example 1. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are the same as in Example 1, as shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 148°C, and the 90% distillation point is 332°C; the 10% distillation point of the middle distillate oil is 317°C, and the 90% distillation point is 465°C; the 10% distillation point of the heavy distillate oil is 480°C; all these conditions are similar to those in Example 1. In step (4), the conditions for the selective hydrogenation treatment are the same as in Example 1, as shown in Table 4.

[0146] In this comparative example, the desolidification apparatus is the same as in Example 1. The vacuum distillation apparatus is the same as in Example 1. The hydrogenation pretreatment reactor and the selective hydrogenation reactor, as well as the hydrogenation catalyst packed therein, are the same as in Example 1. The first gas-liquid separation unit and the second gas-liquid separation unit are both the same as in Example 1.

[0147] The main properties of the carbon material raw materials prepared in this comparative example are shown in Table 6.

[0148] Comparative Example 4

[0149] This comparative example provides a method for preparing carbon material raw materials, which includes the following steps:

[0150] (1) The heavy oil is desolidified in a desolidification device to obtain the desolidified product;

[0151] (2) The product obtained after desolidification in step (1) is subjected to hydrogenation pretreatment in a hydrogenation pretreatment reactor, and then separated into gas and liquid phases by a first gas-liquid separation device to obtain the liquid phase product after hydrogenation pretreatment.

[0152] (3) The liquid phase product after hydrogenation pretreatment obtained in step (2) is subjected to vacuum distillation in a vacuum distillation apparatus to obtain light distillate oil, middle distillate oil and heavy distillate oil.

[0153] (4) After mixing the middle distillate oil and heavy distillate oil obtained in step (3), perform hydroring-ring opening treatment in a hydroring-ring opening treatment reactor to obtain the hydroring-ring opening treatment product.

[0154] (5) The product obtained after hydrogenation ring-opening treatment in step (4) is subjected to gas-liquid separation by a second gas-liquid separation device, and the resulting liquid phase is the carbon material raw material.

[0155] The heavy oil used in this comparative example is the same as that in Example 1, and its main properties are shown in Table 2.

[0156] In this comparative example, the deconsolidation method in step (1) is the same as in Example 1. The ash content of the deconsolidated product is below 100 ppm. In step (2), the conditions for the hydrogenation pretreatment are the same as in Example 1, as shown in Table 3. In step (3), the 10% distillation point temperature of the light distillate oil is 152°C, and the 90% distillation point is 338°C; the 10% distillation point of the middle distillate oil is 321°C, and the 90% distillation point is 465°C; the 10% distillation point of the heavy distillate oil is 486°C; all these conditions are similar to those in Example 1. In step (4), the conditions for the hydrogenation ring-opening treatment are the same as in Example 1, as shown in Table 5.

[0157] In this comparative example, the desolidification apparatus is the same as in Example 1. The vacuum distillation apparatus is the same as in Example 1. The hydrogenation pretreatment reactor and the hydrogenation ring-opening reactor, as well as the hydrogenation catalyst packed therein, are the same as in Example 1. The first gas-liquid separation apparatus and the second gas-liquid separation apparatus are both the same as in Example 1.

[0158] The main properties of the carbon material raw materials prepared in this comparative example are shown in Table 6.

[0159] Table 2 Main Properties of Heavy Oil

[0160] Table 3 Conditions for Hydrotreating

[0161] Table 4 Conditions for selective hydrogenation treatment

[0162] Table 5 Conditions for Hydrogenation Ring-Opening Treatment

[0163] Table 6. Product properties and yields of carbon material raw materials

[0164] In Table 6, the effective aromatic hydrocarbon content refers to the content of tricyclic and tetracyclic aromatic hydrocarbons, which was tested according to the specifications in SH / T 0659-1998 "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry)". The sulfur, nitrogen, and asphaltenes contents were tested according to the specifications in GB / T 17040-2019 "Determination of Sulfur Content in Petroleum and Petroleum Products - Energy Dispersive X-ray Fluorescence Spectrometry", SH / T 0657-2007 "Determination of Trace Nitrogen in Liquid Petroleum Hydrocarbons - Oxidation Combustion and Chemiluminescence Methods", and SH / T 0509-2010 "Determination of Four Components in Petroleum Asphalt", respectively. The yield of the carbon material feedstock was calculated as: (Mass of the prepared carbon material feedstock in the 330℃-520℃ distillation range / Mass of the heavy oil feedstock) × 100%.

[0165] The results above show that, within the same operating cycle, compared with Comparative Example 1, Example 1 showed a significant decrease in sulfur and nitrogen content of the carbon material raw material, and a significant increase in effective aromatic hydrocarbon content and yield; compared with Comparative Example 2, Example 2 showed even lower sulfur and nitrogen content of the carbon material raw material, and a significant increase in effective aromatic hydrocarbon content and yield; compared with Comparative Examples 3 and 4, Example 1 showed a significant decrease in nitrogen content of the carbon material raw material, an increase in effective aromatic hydrocarbon content, and a substantial increase in yield.

[0166] Application Example 1

[0167] The carbon material raw materials prepared in the above embodiments and comparative examples are respectively fed into the coking reaction zone for reaction. The outlet temperature of the heater in the coking reaction zone is controlled by temperature variation, with a temperature variation range of 460-510℃ and a temperature variation rate of 5℃ / h. The heated material enters the coke tower through pipeline. The pressure at the top of the coke tower is 0.3MPa. The reaction cycle of the coking reaction zone is 38h. After the coking process is completed, the coke tower is purged with steam and decoked to obtain needle coke.

[0168] The needle-shaped raw coke was calcined in a tube furnace at 1300℃ and then ground to a particle size of 0.2-0.8 mm to obtain cooked coke. The cooked coke was then treated in a continuous graphitization furnace at 2800℃ in a nitrogen atmosphere to obtain graphitized specimens.

[0169] The sulfur content, true density, and fiber content in the microstructure of the needle-shaped coke were tested, and the coefficient of thermal expansion of the graphitized specimen was tested. The results are shown in Table 7.

[0170] Table 7 Properties of Needle Coke Products

[0171] The coefficient of thermal expansion was determined according to GB / T3074.4 "Determination of Coefficient of Thermal Expansion (CTE) of Graphite Electrodes". The sulfur content was determined according to SH / T0313 "Test Method for Petroleum Coke". The true density was determined according to GB / T6155 "Determination of True Density of Carbon Materials". The method for testing the fiber content in the microstructure includes the following steps: Curing the coke with resin, then grinding and polishing it to create a smooth slide; using a polarizing microscope with crossed polarized light as the light source, observing the microstructure of the slide under an oil immersion lens with a 10x eyepiece and a 50x objective. Fibers are defined as microstructures with a unit width of less than 30 μm and a streamlined shape. Multiple fields of view are selected for a sample, and the number of all microstructures (microstructures generally include fibers, regions, and mosaics) in each field of view is observed and counted. The fiber content is calculated as the percentage of fibers in each field of view relative to the total number of microstructures, and the average value of the content across multiple fields of view is taken to obtain the fiber content.

[0172] As shown in Table 7, under the same coking and graphitization conditions, compared with Comparative Example 1, the coefficient of thermal expansion of the graphitized specimen prepared using the carbon material raw material of Example 1 of this invention is significantly lower, and the fiber content of the needle coke product is significantly higher. Compared with Comparative Example 2, the coefficient of thermal expansion of the graphitized specimen prepared using the carbon material raw material of Example 2 of this invention is somewhat lower, and the fiber content of the needle coke product is significantly higher. Compared with Comparative Examples 3 and 4, the coefficient of thermal expansion of the graphitized specimen prepared using the carbon material raw material of Example 1 of this invention is significantly lower, and the fiber content of the needle coke product is significantly higher.

[0173] The needle coke products prepared from the carbon material raw materials in each embodiment of the present invention all exhibit high quality and can be used as high-quality raw materials for preparing graphite electrodes and / or anode materials. Furthermore, multiple experiments have shown that the needle coke products prepared from the carbon material raw materials in each embodiment of the present invention exhibit minimal performance fluctuations and high performance stability.

[0174] Application Example 2

[0175] The carbon material raw materials prepared in the above examples and comparative examples were added to a reactor to prepare mesophase pitch: first, the reaction was carried out at 415℃ and 4.0MPa for 5 hours, with a stirring rate of 500 r / min during the reaction; then, the reactor temperature was lowered to 320℃, and air was introduced at a flow rate of 1.5 L / min, while the stirring rate of the reactor was increased to 120 r / min. After reacting for 2 hours, mesophase pitch was obtained. The properties of the mesophase pitch were tested, and the results are shown in Table 8.

[0176] Table 8 Properties of Mesophase Pitch Products

[0177] The content of the mesophase was determined by observation using a polarizing microscope. Specifically, the mesophase content was obtained by calculating the percentage of the mesophase region to the total field of view. The mesophase region was determined using optical properties (optical anisotropy) known in the art, as well as texture and morphology (spherical, fibrous, or sheet-like forms with relatively regular texture), and with the aid of image analysis software.

[0178] As shown in Table 8, the mesophase pitch products prepared from carbon material raw materials in the various embodiments of the present invention have a high mesophase content, and therefore a high quality. In contrast, the mesophase pitch products prepared from carbon material raw materials in Comparative Examples 1-4 have too low a mesophase content and do not possess high quality. Furthermore, multiple experiments have revealed that the mesophase pitch products prepared from carbon material raw materials in the various embodiments of the present invention have a stable mesophase content, thus exhibiting high performance stability.

[0179] In summary, the carbon material raw materials prepared in the various embodiments of the present invention have high yields, high contents of tricyclic and tetracyclic aromatic hydrocarbons, and low impurity contents. They can be used to prepare high-quality carbon materials, especially for the co-production of high-quality needle coke and mesophase pitch. The needle coke and mesophase pitch prepared using the carbon material raw materials of the present invention both exhibit high quality and high performance stability.

[0180] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing carbon material feedstock by staged hydrogenation of heavy oil, comprising the following steps: (1) The heavy oil is pretreated to obtain the pretreated product; (2) The pretreated product obtained in step (1) is subjected to hydrogenation pretreatment to obtain the hydrogenated pretreated product. (3) The product obtained after hydrogenation pretreatment in step (2) is subjected to vacuum distillation to obtain light distillate oil, middle distillate oil and heavy distillate oil; (4) Selectively hydrogenate the middle distillate oil obtained in step (3) to obtain the product after selective hydrogenation. (5) The heavy distillate oil obtained in step (3) is subjected to hydroring ring-opening treatment to obtain the product after hydroring ring-opening treatment; (6) The product obtained in step (4) after selective hydrogenation and the product obtained in step (5) after hydrogenation ring-opening treatment are post-processed to obtain the carbon material raw material.

2. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (1), based on the total mass of the heavy oil as 100%, the heavy oil has a sulfur content of 0.5-5.0%, an asphaltene content of 1-15%, and an effective aromatic hydrocarbon content of 15-50%; and the heavy oil has a nitrogen content of 900-9000 μg / g and an ash content of 800-7000 ppm.

3. The method for preparing carbon material raw materials by staged hydrogenation of heavy oil according to claim 1, wherein, In step (1), the pretreatment includes desolidification, and the desolidification method includes one or more of the following: filtration, sedimentation and electrostatic separation.

4. The method for preparing carbon material raw materials by staged hydrogenation of heavy oil according to claim 3, wherein, In step (1), the ash content of the pretreated product is less than 100 ppm.

5. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (2), the conditions for the hydrogenation pretreatment include: a hydrogen partial pressure of 0.5-35.0 MPa, a temperature of 250-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000.

6. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 5, wherein, In step (2), the conditions for the hydrogenation pretreatment include: a hydrogen partial pressure of 4.0-20.0 MPa, a temperature of 350-450 °C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800.

7. The method for preparing carbon material raw materials by staged hydrogenation of heavy oil according to claim 1, wherein, In step (2), after the hydrogenation pretreatment, gas-liquid separation is further performed, and the liquid phase product obtained by the gas-liquid separation is the product after the hydrogenation pretreatment.

8. The method for preparing carbon material raw materials by staged hydrogenation of heavy oil according to claim 1, wherein, In step (3), the 10% distillation point temperature of the light distillate oil is 150-250℃, and the 90% distillation point is 300-400℃; the 10% distillation point of the middle distillate oil is 310-390℃, and the 90% distillation point is 380-520℃; the 10% distillation point of the heavy distillate oil is 460-550℃.

9. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 8, wherein, In step (3), the 10% distillation point temperature of the light distillate oil is 200-230℃, and the 90% distillation point is 330-360℃; the 10% distillation point of the middle distillate oil is 320-370℃, and the 90% distillation point is 400-500℃; the 10% distillation point of the heavy distillate oil is 460-520℃.

10. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (4), the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 1.0-35.0 MPa, a temperature of 280-500 °C, and a volume hourly space velocity of 0.5-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-1000.

11. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 10, wherein, In step (4), the conditions for the selective hydrogenation treatment include: a hydrogen partial pressure of 4.0-10.0 MPa, a temperature of 300-450 °C, and a volume hourly space velocity of 0.8-1.2 h⁻¹. -1 The hydrogen-to-oil ratio is 300-800.

12. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (5), the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 5.0-35.0 MPa, a temperature of 320-500 °C, and a volume hourly space velocity of 0.1-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 500-1500.

13. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 12, wherein, In step (5), the conditions for the hydrogenation ring-opening treatment include: a hydrogen partial pressure of 8.0-20.0 MPa, a temperature of 350-450 °C, and a volume hourly space velocity of 0.2-0.8 h⁻¹. -1 The hydrogen-to-oil ratio is 600-1200.

14. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (6), the post-processing includes gas-liquid separation, and the liquid phase product obtained by the gas-liquid separation is the carbon material raw material.

15. The method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 1, wherein, In step (6), based on the total mass of the carbon material raw material as 100%, the effective aromatic hydrocarbon content of the carbon material raw material is 35-60%, the sulfur content is 0.05-0.15%, the asphaltene content is 0.2-1.5%, and the nitrogen content of the carbon material raw material is 500-3000 μg / g.

16. A system for the staged hydrogenation of heavy oil to prepare carbon material feedstock, wherein, The system is used to implement the method for preparing carbon material feedstock by staged hydrogenation of heavy oil according to any one of claims 1-15. The system includes: a pretreatment device, a hydrogenation pretreatment reactor, a vacuum distillation device, a selective hydrogenation reactor, a hydrogenation ring-opening reactor, and a post-treatment device; wherein, the pretreatment device is sequentially connected to the hydrogenation pretreatment reactor and the vacuum distillation device, the vacuum distillation device is provided with a light distillate oil outlet, a middle distillate oil outlet, and a heavy distillate oil outlet, the middle distillate oil outlet is connected to the selective hydrogenation reactor, the heavy distillate oil outlet is connected to the hydrogenation ring-opening reactor, and the selective hydrogenation reactor and the hydrogenation ring-opening reactor are connected to the post-treatment device.

17. The system for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 16, wherein, The pretreatment device includes a desolidification device, which includes one or more of the following: a metal mesh filter, a centrifuge, a flocculation sedimentation device, a high-voltage electric field packed tower, and an inorganic ceramic membrane filter.

18. The system for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 16, wherein, The system further includes a first gas-liquid separation device, which has at least an inlet, a gas phase outlet, and a liquid phase outlet. The inlet of the first gas-liquid separation device is connected to the product outlet of the hydrogenation pretreatment reactor, and the liquid phase outlet of the first gas-liquid separation device is connected to the inlet of the vacuum distillation device.

19. The system for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 16, wherein, The hydrogenation pretreatment reactor, selective hydrogenation treatment reactor, and hydrogenation ring-opening treatment reactor each include one or more of the following: fixed bed reactor, suspended bed reactor, fluidized bed reactor, and moving bed reactor.

20. The system for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 16, wherein, The vacuum distillation apparatus includes one or both of a stripping tower and a fractionation tower.

21. The system for preparing carbon material feedstock by staged hydrogenation of heavy oil according to claim 16, wherein, The post-processing device includes a second gas-liquid separation device, which is provided with at least an inlet, a gas phase outlet, and a liquid phase outlet, and the carbon material raw material flows out from the liquid phase outlet of the second gas-liquid separation device.

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