A method and system for producing needle coke and coated pitch

Abstract

The application discloses a method and system for producing needle coke and coating pitch, and the method comprises the following steps: (1) catalytic oil slurry and ethylene tar enter a hydrogenation reaction unit to generate a hydrogenation reaction; (2) a liquid phase stream obtained through the hydrogenation reaction is contacted with an extractant to generate a reaction, and an extraction phase is separated to obtain a regenerated extractant and an aromatic-rich fraction; (3) the aromatic-rich fraction is cut and separated to obtain a light fraction and a heavy fraction, wherein the heavy fraction enters a delayed coking unit to produce needle coke; (4) the light fraction is contacted with a raffinate phase to enter an oxidation reaction unit to produce coating pitch. The application further provides a system for producing needle coke and coating pitch. The method and system can obtain high-quality needle coke products, and meanwhile, full-fraction high-value utilization of ethylene tar can be realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of petroleum and chemical industry, and particularly relates to a method and system for producing needle coke and coating pitch. BACKGROUND

[0002] The fraction rich in tricyclic and tetracyclic aromatic hydrocarbons in catalytic slurry oil and ethylene tar is a high-quality raw material for producing needle coke, while the heavy fraction contains gum and asphaltene, which needs to be pretreated for removal. The coating pitch used in the field of negative electrode materials has the characteristics of high softening point and low quinoline insoluble, and is usually prepared from catalytic slurry oil, ethylene tar and the like, with no strict limitation on the fraction.

[0003] CN110511785A discloses a method for preparing needle coke raw material from catalytic slurry oil. The specific steps are as follows: first, low-molecular-weight n-alkanes are added to the oil slurry, and after deasphalting, an upper liquid is obtained. The upper liquid is subjected to extraction and desolidification in sequence to obtain an aromatic-rich oil, which is then subjected to hydrodesulfurization treatment to obtain the needle coke raw material. This method uses an extraction-hydrogenation combined process to treat the catalytic slurry oil to remove solids and sulfur, so that it meets the requirements of being used as a needle coke raw material.

[0004] CN115093872A discloses a method for preparing coating pitch. The specific steps are as follows: ethylene tar and catalytic slurry oil are mixed, settled and heated in sequence, and then subjected to oxidative crosslinking catalytic reaction and polycondensation catalytic reaction in sequence to obtain crude pitch. The crude pitch is then extracted to obtain coating pitch with a softening point of 240-265℃ and a quinoline insoluble content of 0.4wt%-1wt%. SUMMARY

[0005] In view of the deficiencies in the prior art that the quality of needle coke products is difficult to meet the use requirements and ethylene tar is difficult to be efficiently utilized, the present application provides a method and system for producing needle coke and coating pitch, which can obtain high-quality needle coke products and realize high-value utilization of the whole fraction of ethylene tar.

[0006] The first aspect of the present application discloses a method for producing needle coke and coating pitch, which comprises the following steps:

[0007] (1) catalytic slurry oil and ethylene tar enter a hydrogenation reaction unit and undergo hydrogenation reaction in the presence of hydrogen and a hydrogenation catalyst;

[0008] (2) the liquid phase stream obtained by hydrogenation reaction in step (1) is contacted with an extractant to obtain a raffinate phase and an extract phase, wherein the extract phase enters a solvent recovery unit to separate regenerated extractant and aromatic-rich fraction;

[0009] (3) the light fraction and the heavy fraction are obtained after the aromatic-rich fraction obtained in step (2) is separated by cutting, wherein the heavy fraction enters a delayed coking unit for producing needle coke;

[0010] (4) the light fraction obtained in step (3) enters a primary polymerization reaction unit, and the primary polymerization product obtained by the reaction is mixed with the raffinate phase obtained in step (2) to enter a secondary polymerization reaction unit, and the secondary polymerization product obtained by the reaction enters an oxidation reaction unit for producing coating pitch.

[0011] Further, in the method for producing needle coke and coating pitch, the catalytic slurry in step (1) has an ash content of not more than 0.01 wt%, preferably not more than 0.005 wt%, and a sulfur content of more than 0.5 wt%, preferably 0.8 wt%-1.5 wt%.

[0012] Further, in the method for producing needle coke and coating pitch, the catalytic slurry in step (1) can be subjected to a solid-removing treatment according to the situation, and the solid-removing treatment can be performed by one or a combination of several of the following methods: filtration, centrifugal sedimentation, flocculation sedimentation, and electrostatic adsorption, preferably by filtration.

[0013] Further, in the method for producing needle coke and coating pitch, the mass ratio of the catalytic slurry to the ethylene tar in step (1) is 1:1-1:0.001, preferably 1:0.5-1:0.01.

[0014] Further, in the method for producing needle coke and coating pitch, the hydrogenation reaction unit in step (1) is provided with at least one hydrogenation reactor, which can be one or a combination of several of the following reactors: a fixed bed reactor, a suspended bed reactor, and a boiling bed reactor, preferably a fixed bed reactor.

[0015] Further, in the method for producing needle coke and coating pitch, the hydrogenation catalyst in step (1) comprises a carrier and an active metal component supported on the carrier, wherein the carrier can be an inorganic refractory oxide such as alumina, and the active metal can be selected from the group consisting of Group VI B and / or Group VIII metals, specifically one or a combination of several of the following metals: Mo, W, Co, and Ni; and the active metal exists in the form of an oxide. The hydrogenation catalyst can be prepared by a method known in the art, or a commercially available catalyst having a hydrogenation and desulfurization function can be used, such as the FZC and / or FH series hydrogenation catalysts developed by Sinopec (Dalian) Petroleum Chemical Research Institute Co., Ltd.

[0016] Further, in the above process for producing needle coke and coking pitch, the operating conditions of the hydrogenation reaction unit in step (1) are as follows: the reaction temperature is 310-450°C, preferably 340-390°C; the reaction pressure is 2-20 MPa, preferably 4-8 MPa; the hydrogen / oil volume ratio is 100-2500, preferably 800-1800; the liquid hourly space velocity is 0.1-2.0 h -1 -1.2 h -1 , preferably 0.6-1.2 h -1 -1.2 h -1 .

[0017] Further, in the above process for producing needle coke and coking pitch, the sulfur content of the liquid phase stream obtained by the hydrogenation reaction in step (1) is not higher than 0.5 wt%, preferably not higher than 0.4 wt%.

[0018] Further, in the above process for producing needle coke and coking pitch, the extraction unit in step (2) comprises at least one extraction column. The operating temperature of the extraction unit is 30-110°C, preferably 40-80°C. Preferably, the liquid phase stream obtained by the hydrogenation reaction in step (1) and the extraction agent are contacted in countercurrent flow for mass transfer.

[0019] Further, in the above process for producing needle coke and coking pitch, the extraction agent in step (2) is selected from one or more of C3-C 12 paraffins, C3-C 12 naphthenes, preferably one or more of C5-C 12 normal alkanes, C5-C 12 isomeric alkanes; and the specific extraction agent can be one or more of n-propane, i-propane, n-butane, i-butane, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane.

[0020] Further, in the above process for producing needle coke and coking pitch, the mass ratio of the liquid phase stream obtained by the hydrogenation reaction in step (1) to the extraction agent is 1:0.5-1:5, preferably 1:1-1:2.

[0021] Further, in the above process for producing needle coke and coking pitch, the regenerated extraction agent obtained in step (2) is returned for reuse.

[0022] Further, in the above process for producing needle coke and coking pitch, the sum of the gum and pitch contents of the aromatic-rich fraction in step (2) is not higher than 15 wt%, preferably not higher than 5 wt%.

[0023] Further, in the above process for producing needle coke and coking pitch, the 5% distillation temperature of the heavy fraction in step (2) is not less than 340°C, preferably 370-420°C.

[0024] Further, in the process for producing needle coke and coating pitch as described above, the delayed coking unit in step (3) comprises at least one heating furnace, two coke drums and one coking fractionating column. The coke drums are always kept in at least one reaction stage and at least one purging and decoking stage.

[0025] Further, in the process for producing needle coke and coating pitch as described above, the heavy fraction in step (3) is reacted in the delayed coking unit, and the coking oil gas obtained from the reaction is introduced into the coking separation unit to obtain coking gas, coking light oil and coking wax oil by separation, and the coking wax oil is returned to the delayed coking unit as a circulating oil.

[0026] Further, in the process for producing needle coke and coating pitch as described above, the operating conditions of the delayed coking unit for producing needle coke are as follows: the heating furnace outlet temperature is 420-560°C, preferably 440-530°C, and the temperature rising rate is 0.5-30°C / h. The coke drum overhead pressure is 0.01-2.5 MPa, preferably 0.2-1.3 MPa. The operation can be carried out at constant pressure or at variable pressure, and if variable pressure is used, the pressure variation rate is 0.1-5 MPa / h. The reaction cycle is generally 10-72 h, preferably 32-54 h.

[0027] Further, in the process for producing needle coke and coating pitch as described above, the operating conditions of the primary polymerization unit in step (4) are as follows: the reaction temperature is 360-470°C, preferably 400-460°C, the reaction pressure is 0.1-5 MPa, preferably 0.5-2.0 MPa, and the residence time is 3-30 h, preferably 5-20 h.

[0028] Further, in the process for producing needle coke and coating pitch as described above, the softening point of the primary polymerization product is not higher than 120°C, preferably not higher than 60°C, the toluene insoluble content is not more than 3 wt%, preferably not more than 0.5 wt%, and the quinoline insoluble content is not more than 1 wt%, preferably not more than 0.2 wt%.

[0029] Further, in the process for producing needle coke and coating pitch as described above, the mass ratio of the primary polymerization product to the raffinate phase is 1:0.1-1:3, preferably 1:0.3-1:1.5.

[0030] Further, in the above method for producing needle coke and coking pitch, the operating conditions of the secondary polymerization unit in step (4) include: a reaction temperature of 360-470°C, preferably 380-440°C, a reaction pressure of 0.1-5 MPa, preferably 0.5-1.5 MPa, a residence time of 3-30 h, preferably 5-15 h, and the secondary polymerization is preferably carried out under stirring, and the stirring rate is further preferably 10-500 r / min, preferably 100-250 r / min.

[0031] Further, in the above method for producing needle coke and coking pitch, the secondary polymerization product has a softening point of 70-180°C, preferably 80-120°C, and a quinoline insoluble content of not more than 2 wt%, preferably not more than 0.8 wt%.

[0032] Further, in the above method for producing needle coke and coking pitch, the oxidation unit comprises at least one oxidation reactor, and can further comprise an oxidation light oil collection system. The mixture of the secondary polymerization product and the raffinate phase is contacted with an oxygen-containing gas in the oxidation reactor to carry out an oxidation reaction, and the oxidation light oil generated in the reaction is discharged from the top of the oxidation reactor to the oxidation light oil collection system, and the coking pitch is collected from the bottom of the oxidation reactor after the reaction is completed.

[0033] Further, in the above method for producing needle coke and coking pitch, the operating conditions of the oxidation unit include: a reaction temperature of 240-350°C, preferably 270-335°C, a reaction time of 0.5-10 h, preferably 1.5-6 h, and a flow rate of the oxygen-containing gas of 0.01-1.5 m 3 / (h·kg), preferably 0.2-0.7 m 3 / (h·kg), preferably 0.2-0.7 m 3 / (h·kg), preferably 0.2-0.7 m 3 / (h·kg).

[0034] Further, in the above method for producing needle coke and coking pitch, the oxygen-containing gas is a mixture of oxygen and an inert atmosphere, and the inert atmosphere can be one or a mixture of nitrogen, helium, argon, etc. In the oxygen-containing gas, the oxygen content is 5-80 vol%, preferably 20-50 vol%, and the specific oxygen-containing gas can be air.

[0035] Further, in the above method for producing needle coke and coking pitch, after the oxidation reaction is completed, the oxidation reactor is vacuumed to an absolute pressure of 0-80 kPa, preferably 0-30 kPa, and the vacuuming time is 1-120 min, preferably 5-30 min.

[0036] Further, in the above method for producing needle coke and coating pitch, the coker light oil can be returned to the primary polymerization reaction unit.

[0037] The second aspect of the present application provides a system for producing needle coke and coating pitch, the system comprising

[0038] a hydrogenation reaction unit for receiving the catalytic slurry oil and the ethylene tar, and performing hydrogenation reaction under the action of hydrogen and a hydrogenation catalyst;

[0039] an extraction unit for receiving the liquid phase stream obtained from the hydrogenation reaction in step (1) and an extractant, and obtaining a raffinate phase and an extract phase after the material is contacted and reacted;

[0040] an extractant recovery unit for receiving the extract phase from the extraction unit, and obtaining regenerated extractant and an aromatic-rich fraction after separation;

[0041] a hydrogenation separation unit for receiving the aromatic-rich fraction obtained from the extractant recovery unit, and obtaining a light fraction and a heavy fraction after separation;

[0042] a delayed coking unit for receiving the heavy fraction to produce needle coke, and obtaining coking gas, coker light oil and coker wax oil after separation of the coking oil gas generated in the reaction;

[0043] a primary polymerization reaction unit for receiving the light fraction, and obtaining a primary polymerization product after reaction;

[0044] a secondary polymerization reaction unit for receiving the primary polymerization product and the raffinate phase, and obtaining a secondary polymerization product after reaction;

[0045] an oxidation unit for receiving the secondary polymerization product from the secondary polymerization reaction unit, and producing high-softening-point pitch after oxidation reaction, and discharging the oxidation light oil generated in the reaction from the top of the oxidation reactor to an oxidation light oil collection system.

[0046] Further, in the above system for producing needle coke and coating pitch, the hydrogenation reaction unit is provided with at least one hydrogenation reactor, which can be one or a combination of fixed bed reactor, suspended bed reactor and ebullated bed reactor, and is preferably a fixed bed reactor.

[0047] Further, in the above system for producing needle coke and coating pitch, the delayed coking unit comprises at least one heating furnace, two coke towers and one coking fractionating tower. The coke towers are always kept in at least one reaction stage and at least one purging and decoking stage.

[0048] Further, in the above system for producing needle coke and coating pitch, the extraction unit is provided with at least one extraction tower.

[0049] The technical effects and advantages of the method and system for producing needle coke and coating pitch provided by the present application mainly embody in the following aspects:

[0050] (1) According to the present application, the catalytic oil slurry and the ethylene tar are mixed into the hydrogenation reaction unit, and since the ethylene tar contains a large amount of aromatic olefins, the carbon-carbon double bond of the olefin is easier to be hydrogenated than the carbon-carbon double bond of the aromatic ring, so in the hydrogenation reaction unit, the first to occur is the olefin double bond saturation reaction of the aromatic olefin in the ethylene tar, followed by the catalytic oil slurry hydrodesulfurization reaction, and finally the carbon-carbon double bond saturation reaction of the aromatic hydrocarbon occurs, and due to the existence of the competition reaction, the aromatic ring saturation rate of the catalytic oil slurry can be effectively reduced, and the generation of too much aromatic hydrocarbon with a large amount of alkyl side chain or cycloalkyl side chain to cause the decrease of the number of aromatic ring and affect the mechanical properties of the needle coke can be avoided.

[0051] (2) According to the present application, after the ethylene tar is subjected to the hydroprocessing, the content of gum / resin in the ethylene tar is greatly reduced, and the thermal stability is significantly improved, so that the risk of coking of the furnace tube of the subsequent delayed coking system can be reduced.

[0052] (3) According to the present application, after the hydrogenation product passes through the extraction unit, the aromatic-rich fraction is obtained, the properties of the aromatic-rich fraction meet the requirements for producing high-quality needle coke, and the content of gum / resin in the raffinate phase is relatively high, which can be used for producing coating pitch, so that the utilization value of the catalytic oil slurry and the ethylene tar can be maximized.

[0053] (4) According to the present application, the light fraction enters the first-stage polymerization reaction unit and the second-stage polymerization reaction unit in sequence, so that the components gradually become heavier, and the raffinate phase with relatively heavy components directly enters the second-stage polymerization reaction unit, the softening point of the second-stage polymerization product is controlled by the reaction depth, and finally the second-stage polymerization product is sent to the oxidation reaction unit to further improve the softening point and inhibit the generation of quinoline insolubles, and through the graded utilization of the components in the raw material, the effective utilization rate of the catalytic oil slurry and the ethylene tar is greatly improved, and the economic value of the overall process flow is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 The method and system for producing needle coke and coating pitch provided by the present application are shown in the schematic diagram. DETAILED DESCRIPTION

[0055] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0056] Unless otherwise explicitly stated, in the entire specification and claims, the term "comprise" or its variants such as "contain" or "include" and the like will be understood to encompass the stated element or components, without excluding other elements or components.

[0057] For the purposes of this document, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", and the like, can be used to describe an element's or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the object in use or operation in addition to the orientations depicted in the figures. For example, if an object is inverted or rotated 90 degrees, then an element described as "below" or "beneath" another element or feature would be oriented "above" or "over" the other element or feature. Thus, the exemplary term "below" can encompass both an orientation of below and above. The object can be otherwise oriented (e.g., at 45 degrees) and the spatially relative terms used herein interpreted accordingly.

[0058] In this document, the terms "first", "second", etc. are used to distinguish between two different elements or portions of an element, and are not used to designate a particular position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can be interchanged with each other.

[0059] In this document, all numerical values of parameters (e.g., quantities or conditions) should be understood to be modified in all instances by the term "about" unless otherwise indicated expressly to the contrary.

[0060] In this document, the sulfur content is determined by the method of GB / T 24526; the Hardgrove grindability index is determined by the method of GBT 2565; and the particle strength is determined by the method of Appendix B in T / ZGTS 002.

[0061] In this document, the properties of the catalytic slurry oil and ethylene tar used in the examples and comparative examples are shown in Table 1.

[0062] In this document, the hydrogenation catalyst used is FZC-34BT hydrogenation catalyst developed by Sinopec (Dalian) Petroleum Chemical Research Institute Co., Ltd.

[0063] As Figure 1As shown, according to the present application, the catalytic oil slurry 1, the ethylene tar 2 and the hydrogen 4 are mixed into the hydrogenation reaction unit 11 to occur hydrogenation reaction under the action of the hydrogenation catalyst, the liquid phase stream 9 obtained by the hydrogenation reaction is contacted with the extractant 3 in the extraction unit 5 to obtain the raffinate phase 7 and the extract phase 8, wherein the extract phase 8 enters the solvent recovery unit 6 to obtain the regenerated extractant 10 and the aromatic-rich fraction 12 after separation; the regenerated extractant 10 returns to the extraction unit 5 for recycling; the aromatic-rich fraction 12 enters the separation unit 13 to obtain the heavy fraction 14 and the light fraction 15 after separation; the heavy fraction 14 enters the delayed coking unit 16, and the coking oil gas 17 obtained by the reaction enters the coking separation unit 18 to obtain the coking gas 19, the coking light oil 20 and the coking wax oil 21 after separation; the coking light oil 20 is recycled to the primary polymerization reaction unit 22 through the pipeline for treatment; the light fraction 15 enters the primary polymerization reaction unit 22, and the primary polymerization product 23 and the raffinate phase 7 enter the secondary polymerization reaction unit 28 together, and the secondary polymerization product 29 enters the oxidation unit 24 to occur oxidation reaction with the oxygen-containing gas 25 to obtain the oxidized pitch 27 and the oxidation light oil 26, wherein the oxidation light oil 26 can be discharged or returned to the secondary polymerization reaction unit 28.

[0064] Example 1

[0065] Example 1 adopts the method of the present application Figure 1 As shown, according to the present application, the catalytic oil slurry 1, the ethylene tar 2 and the hydrogen 4 are mixed into the hydrogenation reaction unit 11 to occur hydrogenation reaction under the action of the hydrogenation catalyst, the liquid phase stream 9 obtained by the hydrogenation reaction is contacted with the extractant 3 in the extraction unit 5 to obtain the raffinate phase 7 and the extract phase 8, wherein the extract phase 8 enters the solvent recovery unit 6 to obtain the regenerated extractant 10 and the aromatic-rich fraction 12 after separation; the regenerated extractant 10 returns to the extraction unit 5 for recycling; the aromatic-rich fraction 12 enters the separation unit 13 to obtain the heavy fraction 14 and the light fraction 15 after separation; the heavy fraction 14 enters the delayed coking unit 16, and the coking oil gas 17 obtained by the reaction enters the coking separation unit 18 to obtain the coking gas 19, the coking light oil 20 and the coking wax oil 21 after separation; the coking light oil 20 is recycled to the primary polymerization reaction unit 22 through the pipeline for treatment; the light fraction 15 enters the primary polymerization reaction unit 22, and the primary polymerization product 23 and the raffinate phase 7 enter the secondary polymerization reaction unit 28 together, and the secondary polymerization product 29 enters the oxidation unit 24 to occur oxidation reaction with the oxygen-containing gas 25 to obtain the oxidized pitch 27 and the oxidation light oil 26, wherein the oxidation light oil 26 can be discharged or returned to the secondary polymerization reaction unit 28.

[0066] The operation parameters of the hydrogenation reaction unit, the extraction unit, the delayed coking unit, the primary polymerization reaction unit, the secondary polymerization reaction unit and the oxidation unit are listed in Table 2, the material properties are listed in Table 3, the properties of the needle coke are listed in Table 4, and the properties of the coated pitch are listed in Table 5.

[0067] According to the yield of the needle coke and the coated pitch, the effective utilization rate of the catalytic oil slurry and the ethylene tar is 37.69wt%.

[0068] Example 2

[0069] Example 2 adopts the method of the present application Figure 1The method shown differs from Example 1 in that the coker light oil in Example 2 continues to react in the first polymerization reaction unit. The extractant is n-pentane: isobutane = 1:1.3 (mass ratio).

[0070] The operating parameters of the hydrogenation reaction unit, the extraction unit, the delayed coking unit, the first polymerization reaction unit, the second polymerization reaction unit and the oxidation unit are listed in Table 2, the material properties are listed in Table 3, the properties of the needle coke are listed in Table 4, and the properties of the coating pitch are listed in Table 5. According to the needle coke and coating pitch yield, the effective utilization rate of the catalytic oil slurry and ethylene tar is 34.37 wt%.

[0071] Example 3

[0072] Example 3 uses the process of the present application Figure 1 The method shown differs from Example 1 in that the first polymerization reaction unit is cancelled, and the light fraction is directly discharged from the device.

[0073] The operating parameters of the hydrogenation reaction unit, the extraction unit, the delayed coking unit, the second polymerization reaction unit and the oxidation unit are listed in Table 2, the material properties are listed in Table 3, the properties of the needle coke are listed in Table 4, and the properties of the coating pitch are listed in Table 5. According to the needle coke and coating pitch yield, the effective utilization rate of the catalytic oil slurry and ethylene tar is 33.83 wt%.

[0074] Comparative Example 1

[0075] In Comparative Example 1, a catalytic oil slurry distillation-hydrogenation-coking combined process route is used. The catalytic oil slurry enters the vacuum distillation device and is separated into reduced top oil, middle distillate oil and reduced bottom oil. The middle distillate oil enters the hydrogenation reaction unit, and the hydrogenation product is separated to obtain hydrogenation tail oil and hydrogenation light oil. The hydrogenation tail oil enters the delayed coking unit to produce needle coke, and the coking oil gas is separated to obtain coking gas, coking light oil and coking wax oil, wherein the coking wax oil is returned to the delayed coking unit as a circulating oil.

[0076] The operating parameters of the hydrogenation reaction unit and the delayed coking unit are listed in Table 6, the material properties are listed in Table 7, and the properties of the needle coke are listed in Table 4. Although the needle coke yield can reach 31.04 wt%, the comprehensive utilization rate according to the total feed amount is lower than that of the examples, and the particle strength of the needle coke is relatively low, affecting the use.

[0077] Comparative Example 2

[0078] In the comparative example 2, the mixed oil of catalytic oil slurry and ethylene tar was used in the hydrogenation-distillation topping-coking combined process route. The catalytic oil slurry and the ethylene tar were mixed in a mass ratio of 1:0.08, and then mixed with hydrogen to enter the hydrogenation reaction unit, and the hydrogenation reaction occurred under the action of the hydrogenation catalyst. The liquid phase stream obtained by the hydrogenation reaction entered the separation unit, and the light fraction and the heavy fraction were obtained by separation. The heavy fraction entered the delayed coking unit to produce the needle coke.

[0079] The operating parameters of the hydrogenation reaction unit and the delayed coking unit are listed in Table 6, the material properties are listed in Table 7, and the properties of the needle coke are listed in Table 4.

[0080] Although the needle coke yield is relatively high, 33.57wt%, and the particle strength is also relatively high, the key technical index of the thermal expansion coefficient is higher than that of the examples, and the properties are poor.

[0081] Comparative example 3

[0082] In the comparative example 3, the ethylene tar directly entered the oxidation unit to produce the coating pitch, and the operating parameters are listed in Table 8. The pitch yield and properties are listed in Table 5.

[0083] Although the pitch yield is 18.35wt%, the comprehensive utilization rate of the ethylene tar is lower than that of the examples.

[0084] Comparative example 4

[0085] In the comparative example 4, the catalytic oil slurry directly entered the oxidation unit to produce the coating pitch, and the operating parameters are listed in Table 8. The pitch yield and properties are listed in Table 5.

[0086] The oxidation reaction time is prolonged, and the softening point is still lower than that of the examples and other comparative examples.

[0087] Comparative example 5

[0088] In the comparative example 5, the catalytic oil slurry directly entered the polymerization reaction unit, and the polymerization product entered the oxidation unit to produce the coating pitch.

[0089] The operating parameters of the polymerization unit and the oxidation unit are listed in Table 9, and the material properties are listed in Table 10. The pitch yield and properties are listed in Table 5.

[0090] Although the pitch yield is 20.27wt%, the comprehensive utilization rate of the catalytic oil slurry is lower than that of the examples.

[0091] Comparative example 6

[0092] In the comparative example 6, the catalytic oil slurry and the ethylene tar were mixed in a mass ratio of 1:0.3, and then directly entered the polymerization reaction unit. The polymerization product entered the oxidation unit to produce the coating pitch.

[0093] Operating parameters for the polymerization and oxidation units are listed in Table 9, and material properties are listed in Table 10. Asphalt yield and properties are listed in Table 5.

[0094] Although the asphalt yield was 20.11 wt%, the combined utilization of the catalytic oil slurry and ethylene tar was lower than in the example.

[0095] Table 1 Feedstock properties

[0096] Item Ethylene tar FCC slurry oil Ash, wt% 0.017 0.005 Sulfur, wt% 0.019 0.983 Aromatic carbon, mol% 87.4 78.6

[0097] Table 2 Example individual unit operating parameters

[0098]

[0099]

[0100] Table 3 Example material properties

[0101]

[0102] Table 4 Needle coke properties

[0103] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Yield*, wt% 27.51 25.04 25.69 31.04 33.57 Sulfur, wt% 0.39 0.40 0.39 0.40 0.41 Hardgrove grindability index 78 81 75 96 90 Particle strength, wt% 23.66 24.08 23.87 18.83 23.92 coefficient of thermal expansion x 10 6 / °C -1 ]]> 1.13 1.12 1.16 1.15 1.39

[0104] *Based on total feed amount.

[0105] Table 5 Asphalt properties

[0106]

[0107] *Based on total feed amount.

[0108] Table 6 Comparative Example 1 and Comparative Example 2 individual unit operating parameters

[0109]

[0110] Table 7 Comparative Example 1 and Comparative Example 2 delayed coking unit feed properties

[0111]

[0112]

[0113] Table 8 Comparative Example 3 and Comparative Example 4 oxidation unit operating parameters

[0114] Reaction conditions Comparative Example 3 Comparative Example 4 Temperature / °C 310 332 Time / h 5 12 Air flow / m 3 • (h-kg) -1 ]]> 0.5 0.5 Vacuum absolute pressure / kPa 15 15 Vacuum time / min 15 20

[0115] Table 9 Comparative Example 5 and Comparative Example 6 individual unit operating parameters

[0116]

[0117] Table 10 Properties of the polymerization products of Comparative Example 5 and Comparative Example 6

[0118] Reaction conditions Comparative Example 5 Comparative Example 6 Softening point / °C 107 112 Quinoline insolubles, wt% 0.10 0.12

Claims

1. A method for producing needle coke and coated bitumen, the method comprising the following steps: (1) Catalytic oil slurry and ethylene tar enter the hydrogenation reaction unit and undergo hydrogenation reaction in the presence of hydrogen and hydrodesulfurization catalyst; (2) The liquid stream obtained from the hydrogenation reaction in step (1) reacts with the extractant to obtain the raffinate phase and the extract phase. The extract phase enters the solvent recovery unit to separate and obtain the regenerated extractant and the aromatic fraction. The extractant is selected from C3-C 12 Alkanes, C3-C 12 One or more of the cycloalkanes; (3) The aromatic fraction obtained in step (2) is cut and separated to obtain light fraction and heavy fraction, wherein the heavy fraction enters the delayed coking unit for the production of needle coke; (4) The light fraction obtained in step (3) enters the primary polymerization reaction unit. The primary polymerization product obtained in the reaction is mixed with the raffinate obtained in step (2) and enters the secondary polymerization reaction unit. The secondary polymerization product obtained in the reaction enters the oxidation unit for the production of coated asphalt.

2. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The ash content of the catalytic oil slurry in step (1) is not higher than 0.01 wt%.

3. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The ash content of the catalytic oil slurry in step (1) is not higher than 0.005 wt%.

4. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sulfur content of the catalytic oil slurry in step (1) is higher than 0.5 wt%.

5. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sulfur content of the catalytic oil slurry in step (1) is 0.8wt%-1.5wt%.

6. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The mass ratio of catalytic oil slurry to ethylene tar in step (1) is 1:1 to 1:0.

001.

7. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The mass ratio of catalytic oil slurry to ethylene tar in step (1) is 1:0.5 to 1:0.

01.

8. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the hydrogenation reaction unit in step (1) are as follows: reaction temperature 310℃~450℃, reaction pressure 2MPa~20MPa, hydrogen-to-oil volume ratio 100~2500, and liquid hourly space velocity 0.1h. -1 ~2.0h -1 .

9. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the hydrogenation reaction unit in step (1) are as follows: reaction temperature 340℃~390℃, reaction pressure 4MPa~8MPa, hydrogen-to-oil volume ratio 800~1800, and liquid hourly space velocity 0.6h. -1 ~1.2h -1 .

10. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sulfur content of the liquid phase stream obtained from the hydrogenation reaction in step (1) is not higher than 0.5 wt%.

11. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sulfur content of the liquid phase stream obtained from the hydrogenation reaction in step (1) is not higher than 0.4 wt%.

12. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating temperature of the extraction unit in step (2) is 30℃~110℃.

13. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating temperature of the extraction unit in step (2) is 40℃~80℃.

14. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The extractant in step (2) is selected from C5-C. 12 n-Alkanes, C5-C 12 One or more of the isoalkanes.

15. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The extractant in step (2) is one or more of the following: n-propane, isopropane, n-butane, isobutane, n-pentane, isopentane, n-hexane, isohexane, and n-heptane.

16. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The mass ratio of the liquid phase stream obtained from the hydrogenation reaction in step (1) to the extractant is 1:0.5 to 1:

5.

17. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: In step (1), the mass ratio of the liquid phase stream obtained from the hydrogenation reaction to the extractant is 1:1 to 1:

2.

18. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sum of the gum and asphaltenes content of the aromatic fraction in step (2) shall not exceed 15 wt%.

19. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The sum of the gum and asphaltenes content of the aromatic fraction in step (2) shall not exceed 5 wt%.

20. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: In step (3), the 5% distillation temperature of the heavy fraction shall not be less than 340℃.

21. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: In step (3), the 5% distillation temperature of the heavy fraction is 370℃~420℃.

22. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The heavy fraction in step (3) enters the delayed coking unit to react, and the resulting coking oil gas enters the coking separation unit. After separation, coking gas, coking light oil and coking wax oil are obtained. The coking wax oil is returned to the delayed coking unit as circulating oil.

23. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions for producing needle coke in the delayed coking unit are as follows: the outlet temperature of the heating furnace is 420℃~560℃, the top pressure of the coke tower is 0.01MPa~2.5MPa, and the reaction cycle is 10h~72h.

24. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions for producing needle coke in the delayed coking unit are as follows: furnace outlet temperature is 440℃~530℃; coke tower top pressure is 0.2MPa~1.3MPa; reaction cycle is 32h~54h.

25. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the primary polymerization reaction unit in step (4) include: reaction temperature of 360℃~470℃, reaction pressure of 0.1MPa~5MPa, and residence time of 3h~30h.

26. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the primary polymerization reaction unit in step (4) include: reaction temperature of 400℃~460℃, reaction pressure of 0.5MPa~2.0MPa, and residence time of 5h~20h.

27. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The mass ratio of primary polymerization product to raffinate is 1:0.1 to 1:

3.

28. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The mass ratio of primary polymerization product to raffinate is 1:0.3 to 1:1.

5.

29. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the secondary polymerization reaction unit in step (4) include: reaction temperature of 360℃~470℃, reaction pressure of 0.1MPa~5MPa, and residence time of 3h~30h.

30. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions of the secondary polymerization reaction unit in step (4) include: reaction temperature of 380℃~440℃, reaction pressure of 0.5MPa~1.5MPa, and residence time of 5h~15h.

31. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The softening point of the secondary polymerization product is 70℃~180℃, and the content of quinoline insoluble matter is not greater than 2wt%.

32. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The softening point of the secondary polymerization product is 80℃~120℃, and the content of quinoline insoluble matter is not greater than 0.8wt%.

33. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions for the oxidation unit include: a reaction temperature of 240℃~350℃ and a reaction time of 0.5h~10h.

34. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: The operating conditions for the oxidation unit include: a reaction temperature of 270℃ to 335℃ and a reaction time of 1.5h to 6h.

35. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: Oxygen-containing gas is a mixture of oxygen and an inert atmosphere, which is one or more of nitrogen, helium, and argon; the oxygen volume content in oxygen-containing gas is 5% to 80%.

36. The method for producing needle coke and coated bitumen according to claim 35, characterized in that: The oxygen content of oxygen-containing gas is 20% to 50% by volume.

37. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: After the oxidation reaction is completed, the oxidation reactor is evacuated at an absolute pressure of 0–80 kPa for 1–120 min.

38. The method for producing needle coke and coated bitumen according to claim 1, characterized in that: After the oxidation reaction is completed, the oxidation reactor is evacuated at an absolute pressure of 0–30 kPa for 5–30 min.

39. The method for producing needle coke and coated bitumen according to claim 22, characterized in that: The coking oil is returned to the primary polymerization reaction unit.

40. A system for producing needle coke and coated bitumen, the system comprising a hydrogenation reaction unit, an extraction unit, a solvent recovery unit, a separation unit, a delayed coking unit, a primary polymerization reaction unit, a secondary polymerization reaction unit, and an oxidation unit; in The hydrogenation reaction unit is used to receive catalytic slurry and ethylene tar, and to carry out the hydrogenation reaction under the action of hydrogen and hydrodesulfurization catalyst; The extraction unit is used to receive the liquid phase stream and extractant obtained from the hydrogenation reaction in step (1). After the materials come into contact with each other, the raffinate phase and the extract phase are obtained. The solvent recovery unit is used to receive the extract phase from the extraction unit, and after separation, obtain the regenerated extractant and aromatic fraction. The separation unit receives the aromatic fraction from the extractant recovery unit and separates it into light and heavy fractions. The delayed coking unit is used to receive heavy distillate to produce needle coke. The coking oil and gas generated by the reaction enter the coking separation unit, and after separation, coking gas, coking light oil and coking wax oil are obtained. The primary polymerization reaction unit is used to receive light fractions and obtain primary polymerization products after the reaction. The secondary polymerization reaction unit is used to receive the primary polymerization product and the raffinate phase, and the secondary polymerization product is obtained after the reaction. The oxidation unit receives the secondary polymerization products from the secondary polymerization reaction unit, undergoes an oxidation reaction to produce high softening point asphalt, and the oxidized light oil generated by the reaction is discharged from the top of the oxidation reactor to the oxidized light oil collection system.

41. The system for producing needle coke and coated bitumen according to claim 40, characterized in that: The hydrogenation reaction unit is equipped with at least one hydrogenation reactor, which is one or more of the following: fixed bed reactor, suspended bed reactor, and fluidized bed reactor.

42. The system for producing needle coke and coated bitumen according to claim 41, characterized in that: The hydrogenation reactor is a fixed-bed reactor.

43. The system for producing needle coke and coated bitumen according to claim 40, characterized in that: The delayed coking unit includes at least one heating furnace, two coke towers, and one coking fractionation tower.

44. The system for producing needle coke and coated bitumen according to claim 40, characterized in that: The extraction unit is equipped with at least one extraction tower.

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