A co-production process and system of high softening point pitch and needle coke

Abstract

The application discloses a kind of high softening point pitch and needle coke co-production process and system, the co-production process is that the extraction phase obtained by the reaction of ethylene tar and extractant is obtained after the recovery of extractant Rich aromatic oil;The obtained rich aromatic oil, catalytic oil slurry, hydrogen are mixed into hydrogenation reaction unit and hydrogenation reaction occurs, and the hydrogenation liquid phase material obtained by reaction is separated to obtain hydrogenation light oil and hydrogenation tail oil;The obtained hydrogenation tail oil is used to produce needle coke;The obtained hydrogenation light oil is used to produce high softening point pitch.The process of the application can effectively solve the problems of poor quality of needle coke caused by catalytic oil slurry due to hydrogenation treatment and low utilization rate of ethylene tar.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of petrochemical industry, and particularly relates to a process and system for producing needle coke and simultaneously co-producing high softening point pitch. BACKGROUND

[0002] Catalytic slurry oil, ethylene tar and other aromatic-rich oils are high-quality raw materials for producing needle coke and high softening point pitch, but there are certain differences in the requirements of raw materials for needle coke and high softening point pitch. Needle coke requires low sulfur content and low content of resin / asphaltene, while high softening point pitch used as coating pitch requires low quinoline insoluble content and has no limit on the content of resin / asphaltene.

[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 the removal of asphaltene, an upper liquid is obtained. The upper liquid is subjected to extraction and desolidification in sequence to obtain an aromatic-rich oil, which is 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 meet the requirements of needle coke raw material.

[0004] CN114736705A discloses a method for preparing coating pitch from ethylene tar. The specific steps are as follows: first, the ethylene tar is subjected to distillation, and the heavy component of the obtained tar is introduced into an oxidation crosslinking reactor, and at the same time, an oxidizing gas is introduced into the oxidation crosslinking reactor to perform oxidation crosslinking reaction. After the oxidation crosslinking reaction is completed, stripping gas is introduced into the oxidation crosslinking reactor, and the light component is carried out. The remaining in the reactor is the coating pitch. SUMMARY

[0005] In view of the deficiencies in the existing production processes of needle coke and high softening point pitch, the main purpose of the present application is to provide a co-production process and system of high softening point pitch and needle coke, which can effectively solve the problems of poor quality of needle coke produced from catalytic slurry oil due to hydrogenation treatment and low utilization rate of ethylene tar.

[0006] The first aspect of the present application relates to a co-production process of high softening point pitch and needle coke, comprising the following steps:

[0007] (1) under contact conditions, ethylene tar is contacted with an extractant to obtain a raffinate phase and an extract phase, and the extract phase is introduced into an extractant recovery unit to separate regenerated extractant and aromatic-rich oil;

[0008] (2) the aromatic-rich oil obtained in step (1), catalytic slurry oil and hydrogen are mixed and introduced into a hydrogenation reaction unit to perform hydrogenation reaction under the action of a hydrogenation catalyst, and the hydrogenation liquid phase material obtained by the reaction is separated to obtain hydrogenation light oil and hydrogenation tail oil;

[0009] (3) The hydrogenation tail oil obtained in step (2) enters a delayed coking unit to produce needle coke;

[0010] (4) The hydrogenation light oil obtained in step (2) enters a polymerization reaction unit, and the polymerization product obtained by the reaction is mixed with the raffinate obtained in step (1) to enter an oxidation unit to produce high softening point pitch by oxidation reaction.

[0011] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the contacting reaction of the ethylene tar and the extractant in step (1) is carried out in an extraction unit, and the extraction unit is provided with at least one extraction tower; the reaction operating temperature is 30-110°C, preferably 40-80°C; and the contacting between the ethylene tar and the extractant is preferably in countercurrent mode.

[0012] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the extractant in step (1) is selected from one or more of C3-C 12 paraffins, C3-C 12 naphthenes, preferably C5-C 12 normal alkanes, C5-C 12 isomeric alkanes; and the specific extractant can be one or more of n-propane, i-propane, n-butane, i-butane, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane.

[0013] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the mass ratio of the ethylene tar to the extractant in step (1) is 1:0.5-1:5, preferably 1:1-1:2.

[0014] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the regenerated extractant separated by the extractant recovery unit in step (1) is returned to the extraction unit for recycling.

[0015] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the sum of the gum and asphaltene contents of the aromatic-rich oil in step (1) is not higher than 15wt%, preferably not higher than 12wt%, and further preferably not higher than 8wt%.

[0016] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the ash content of the catalytic oil slurry in step (2) is not higher than 0.01wt%, and preferably the ash content is not higher than 0.005wt%. The catalytic oil slurry generally needs to be subjected to desolidification treatment, which can be carried out by one or a combination of several of the following modes: filtration, centrifugal sedimentation, flocculation sedimentation, and electrostatic adsorption, and the filtration mode is preferred.

[0017] Further, in the co-production process of high softening point pitch and needle coke, the sulfur content of the catalytic oil slurry in step (2) is higher than 0.5 wt%, preferably 0.8 wt% to 1.5 wt%.

[0018] Further, in the co-production process of high softening point pitch and needle coke, the mass ratio of the catalytic oil slurry to the aromatic-rich oil in step (2) is 1:1 to 1:0.001, preferably 1:0.2 to 1:0.01.

[0019] Further, in the co-production process of high softening point pitch and needle coke, at least one hydrogenation reactor is provided in the hydrogenation reaction unit in step (2), which can be one or a combination of fixed bed reactor, suspended bed reactor and ebullated bed reactor, preferably a fixed bed reactor.

[0020] Further, in the co-production process of high softening point pitch and needle coke, the hydrogenation catalyst in step (2) is a catalyst with hydrogenation desulfurization function, which generally uses alumina as the carrier and loads oxides of Group ⅥB and / or Group VIII metals as the active components, and the active components can be one or a combination of oxides of Mo, W, Co, Ni and the like. The hydrogenation catalyst can be prepared by the existing method in the art, or the existing commercial hydrogenation desulfurization catalysts, such as FZC and / or FH series hydrogenation catalysts developed by Sinopec (Dalian) Petroleum Chemical Research Institute Co., Ltd.

[0021] Further, in the co-production process of high softening point pitch and needle coke, the operating conditions of the hydrogenation reaction in step (2) are as follows: the reaction temperature is 310°C to 450°C, preferably 340°C to 390°C; the reaction pressure is 2 MPa to 20 MPa, preferably 4 MPa to 8 MPa; the hydrogen / oil volume ratio is 100 to 2500, preferably 800 to 1800; and the liquid hourly space velocity is 0.1 h -1 ~ 2.0 h -1 , preferably 0.6 h -1 ~ 1.5 h -1 .

[0022] Further, in the co-production process of high softening point pitch and needle coke, the sulfur content of the hydrogenation liquid phase material obtained in step (2) is not higher than 0.5 wt%, preferably not higher than 0.4 wt%.

[0023] Further, in the co-production process of high softening point pitch and needle coke, the 5% distillation temperature of the hydrogenation tail oil in step (2) is not less than 340°C, preferably 370°C to 410°C.

[0024] Further, in the process for co-production of high softening point pitch and needle coke, the delayed coking unit in step (3) comprises at least one heating furnace, two coke towers and one coking fractionating tower. At least one of the coke towers is always in the reaction stage and at least one is in the blowing and decoking stage.

[0025] Further, in the process for co-production of high softening point pitch and needle coke, the operating conditions for producing needle coke in step (3) include: 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 tower overhead pressure is 0.01-2.5 MPa, preferably 0.2-1.3 MPa; it can be operated at constant pressure or variable pressure, and if variable pressure is used, the variable pressure rate is generally controlled to be 0.1-5 MPa / h; and the reaction period is generally 10-72 h, preferably 32-54 h.

[0026] Further, in the process for co-production of high softening point pitch and needle coke, the hydrogenated tail oil in step (3) enters the delayed coking unit to react, and the coking oil gas obtained from the reaction enters the coking separation unit to obtain coking gas, coking light oil and coking wax oil after separation, and the coking wax oil is recycled back to the delayed coking unit.

[0027] Further, in the process for co-production of high softening point pitch and needle coke, the operating conditions for the polymerization unit in step (4) include: the reaction temperature is 360-460°C, preferably 380-440°C, the reaction pressure is 0.1-5 MPa, preferably 0.5-1.5 MPa, and the residence time is 3-20 h, preferably 5-15 h.

[0028] Further, in the process for co-production of high softening point pitch and needle coke, the softening point of the polymerization product in step (4) is 70-180°C, preferably 80-120°C, and the quinoline insoluble content is not more than 2 wt%, preferably not more than 0.8 wt%.

[0029] Further, in the process for co-production of high softening point pitch and needle coke, the mass ratio of the polymerization product to the raffinate phase in step (4) is 1:0.1-1:3, preferably 1:0.3-1:1.5.

[0030] Further, in the process for co-production of high softening point pitch and needle coke, the oxidation unit in step (4) comprises at least one oxidation reactor, and can optionally comprise an oxidation light oil collection system. The mixture of the polymerization product and the raffinate phase is contacted with an oxygen-containing gas in the oxidation reactor to undergo oxidation reaction, and the oxidation light oil generated from the reaction is discharged from the top end of the oxidation reactor to the oxidation light oil collection system, and the high softening point pitch is collected from the bottom of the oxidation reactor after the reaction is completed.

[0031] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the operating conditions of the oxidation reaction in step (4) include: the reaction temperature is 240-350°C, preferably 270-335°C, the reaction time is 0.5-10h, preferably 1.5-6h, the flow rate of the oxygen-containing gas is 0.01-1.5m 3 / (h·kg)~1.5m 3 / (h·kg), preferably 0.2m 3 / (h·kg)~0.7m 3 / (h·kg).

[0032] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the oxygen-containing gas in step (4) is a mixture of oxygen and inert gas, and the inert gas can be one or a mixture of nitrogen, helium, argon, etc. The volume content of oxygen in the oxygen-containing gas is 5%-80%, preferably 20%-50%, and the specific oxygen-containing gas can be air.

[0033] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, after the oxidation reaction, the oxidation reactor is vacuumed to an absolute pressure of 0-80kPa, preferably 0-30kPa, and the vacuuming time is 1-120min, preferably 5-30min.

[0034] Further, in the above-mentioned cogeneration process of high softening point pitch and needle coke, the coking light oil can be returned to the polymerization reaction unit.

[0035] The second aspect of the present application provides a cogeneration system of high softening point pitch and needle coke, which comprises

[0036] an extraction unit for receiving ethylene tar and an extractant, and obtaining a raffinate phase and an extract phase after the ethylene tar is contacted with the extractant;

[0037] an extractant recovery unit for receiving the extract phase from the extraction unit, and obtaining regenerated extractant and aromatic-rich oil after separation;

[0038] a hydrogenation reaction unit for receiving catalytic oil slurry and the aromatic-rich oil from the extractant recovery unit, and carrying out hydrogenation reaction under the action of hydrogen and a hydrogenation catalyst;

[0039] a hydrogenation separation unit for receiving the hydrogenation liquid phase material obtained from the hydrogenation reaction unit, and obtaining hydrogenation light oil and hydrogenation tail oil after separation;

[0040] a delayed coking unit for receiving the hydrogenation tail oil to produce needle coke, and the coking oil gas generated in the reaction enters a coking separation unit, and coking gas, coking light oil and coking wax oil are obtained after separation;

[0041] a polymerization unit for receiving the hydrogenated light oil, and producing a polymerization product after reaction;

[0042] an oxidation unit for receiving the polymerization product from the polymerization unit and the raffinate phase from the extraction unit, and producing a high softening point pitch by oxidation reaction, and discharging the oxidation light oil generated in the oxidation reaction from the top of the oxidation reactor to an oxidation light oil collection system.

[0043] Further, in the cogeneration system of the high softening point pitch and the needle coke, the hydrogenation reaction unit comprises at least one hydrogenation reactor, which can be one or a combination of a fixed bed reactor, a suspended bed reactor and a boiling bed reactor, and is preferably a fixed bed reactor.

[0044] Further, in the cogeneration system of the high softening point pitch and the needle coke, 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.

[0045] Further, in the cogeneration system of the high softening point pitch and the needle coke, the extraction unit comprises at least one extraction tower.

[0046] Further, in the cogeneration system of the high softening point pitch and the needle coke, the oxidation unit comprises at least one oxidation reactor, and can further comprise an oxidation light oil collection system. The mixture of the polymerization product and the raffinate phase is contacted with an oxygen-containing gas in the oxidation reactor to generate 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. After the reaction is completed, the high softening point pitch is collected from the bottom of the oxidation reactor.

[0047] Further, in the cogeneration system of the high softening point pitch and the needle coke, the coking light oil is communicated with the polymerization unit through a pipeline.

[0048] Compared with the prior art, the cogeneration process and system of the high softening point pitch and the needle coke provided by the present application has the following advantages:

[0049] (1) In the cogeneration process and system of the high softening point pitch and the needle coke provided by the present application, the ethylene tar is first subjected to the extraction unit to remove gum / asphaltene to obtain a rich aromatic oil, which is used as a potential raw material for the needle coke. The raffinate phase rich in gum / asphaltene is used for preparing the high softening point pitch, so as to maximize the utilization value of the ethylene tar.

[0050] (2) In the cogeneration process and system of high softening point pitch and needle coke provided by the application, catalytic oil slurry is mixed with aromatic-rich oil to enter a hydrogenation reaction unit. Since the aromatic-rich oil (from ethylene tar) contains aromatic alkenes, the carbon-carbon double bonds of alkenes are easier to be hydrogenated than the carbon-carbon double bonds of aromatic rings. Thus, the carbon-carbon double bond saturation reaction of aromatic alkenes occurs first in the hydrogenation reaction unit, followed by the hydrogenation desulfurization reaction of catalytic oil slurry, and finally the carbon-carbon double bond saturation reaction of aromatic hydrocarbons. Due to the existence of competitive reactions, the aromatic ring saturation rate of catalytic oil slurry can be effectively reduced, and the generation of excessive aromatic hydrocarbons with a large number of alkyl side chains or cycloalkyl side chains can be avoided, thereby reducing the number of aromatic rings and affecting the mechanical properties of needle coke. The process of the application solves the problem of hydrogenation desulfurization of catalytic oil slurry, and part of the carbon-carbon double bonds of aromatic rings are saturated and converted into alkyl side chains. These aromatic hydrocarbons with alkyl side chains will play a hydrogen-donating role in the production of needle coke, hinder the polymerization of molecules to form macromolecules, cause incomplete development of mesophase, and affect the mechanical properties of needle coke.

[0051] (3) In the cogeneration process and system of high softening point pitch and needle coke provided by the application, hydrogenated light oil is sent to a polymerization reaction unit. The hydrogenated light oil with high aromatic content and low sulfur content is upgraded, and the polymerization product with a moderate softening point is used as a raw material of high softening point pitch and is sent to an oxidation reaction unit to further improve the softening and inhibit the generation of quinoline insolubles, thereby effectively improving the economic value of the overall process flow.

[0052] (4) In the cogeneration process and system of high softening point pitch and needle coke provided by the application, the components in catalytic oil slurry and ethylene tar raw materials are classified and utilized, thereby greatly improving the effective utilization rate of catalytic oil slurry and ethylene tar. The whole fraction of raw materials is used for high value-added utilization, thereby greatly improving the economic value. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 A schematic diagram of the cogeneration process and system of high softening point pitch and needle coke provided by the application. DETAILED DESCRIPTION

[0054] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the application is not limited by the specific embodiments.

[0055] Unless otherwise explicitly stated, throughout the specification and claims, the term "comprise" or its variants such as "comprises" or "comprising" will be understood to encompass the stated element or components, without excluding other elements or components.

[0056] 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.

[0057] 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, the terms "first", "second", etc. can be interchanged with each other in some embodiments.

[0058] In this document, all numerical values of parameters (e.g., quantities or conditions) are to be interpreted as being modified in all instances by the term "about", unless otherwise indicated expressly to the contrary.

[0059] 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; the particle strength is determined by the method of Appendix B in T / ZGTS 002; the asphalt softening point is determined by the method of ASTM D 3461; the quinoline insolubles are determined by the method of GB / T 2293; and the organizational structure (fibrous, flaky, mosaic) is determined by the method of YB / T 077.

[0060] As Figure 1As shown, according to the present application, ethylene tar 2 enters the extraction unit 5, and after being contacted with the extractant 3, the raffinate phase 7 and the extract phase 8 are obtained, wherein the extract phase 8 enters the solvent recovery unit 6, and after being separated, the regenerated extractant 10 and the aromatic-rich oil 9 are obtained; the regenerated extractant 10 returns to the extraction unit 5 for recycling; the obtained aromatic-rich oil 9, the catalytic oil slurry 1 and hydrogen 4 are mixed and enter the hydrogenation reaction unit 11, and under the action of the hydrogenation catalyst, hydrogenation reaction occurs, and the obtained hydrogenation liquid phase material 12 enters the hydrogenation separation unit 13, and after being separated, the hydrogenation light oil 15 and the hydrogenation tail oil 14 are obtained; the hydrogenation tail oil 14 enters the delayed coking unit 16, and the coking oil gas 17 generated by the reaction enters the coking separation unit 18, and after being separated, the coking gas 19, the coking light oil 20 and the coking wax oil 21 are obtained; the coking wax oil is recycled back to the delayed coking unit for use, and the coking light oil 20 can be recycled back to the polymerization reaction unit 22 for treatment; the hydrogenation light oil 15 enters the polymerization reaction unit 22, and the obtained polymerization product 23 and the raffinate phase 7 enter the oxidation unit 24 together, and after being contacted with the oxygen-containing gas 25, oxidation reaction occurs, and the obtained oxidation pitch 27 and the oxidation light oil 26 are obtained, wherein the oxidation light oil 26 can be discharged after being collected, or can also be returned to the polymerization reaction unit 22 for further treatment.

[0061] The catalytic oil slurry and the ethylene tar raw material used in the examples and comparative examples of the present application are shown in Table 1. The hydrogenation catalyst used is FZC-34BT hydrogenation catalyst developed by Dalian Institute of Petroleum Chemistry, SINOPEC.

[0062] Example 1

[0063] Example 1 uses the process provided by the present application, and the ethylene tar enters the extraction unit and is contacted with the extractant to separate the raffinate phase and the aromatic-rich oil; the extractant used in the extraction unit is n-pentane:isobutane = 1:1.6 (mass ratio); the catalytic oil slurry and the aromatic-rich oil are mixed in a mass ratio of 1:0.1, and enter the hydrogenation reaction unit together with hydrogen, and after the hydrogenation product is separated, the hydrogenation tail oil and the hydrogenation light oil are obtained; the hydrogenation tail oil is sent to 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; the hydrogenation light oil is mixed with the coking light oil to enter the polymerization reaction unit, and the obtained polymerization product and the raffinate phase enter the oxidation unit to produce oxidation pitch.

[0064] The operating parameters of the extraction unit, the hydrogenation reaction unit, the delayed coking unit, the polymerization reaction unit and the oxidation unit are listed in Table 2, and the properties of the materials are listed in Table 3.

[0065] The yield and properties of the needle coke and the oxidation pitch are listed in Table 4. According to the yield of the needle coke and the oxidation pitch, the comprehensive utilization rate of the catalytic oil slurry and the ethylene tar is 39.35wt%.

[0066] Example 2

[0067] Example 2 is the same as Example 1 except that the coking light oil does not enter the polymerization reaction unit. The extractant used in the extraction unit is n-pentane: isobutane = 1:2 (mass ratio).

[0068] The operating parameters of the extraction unit, hydrogenation reaction unit, delayed coking unit, polymerization reaction unit, and oxidation unit are listed in Table 2, and the material properties are listed in Table 3.

[0069] The yield and properties of the needle coke and oxidized pitch are listed in Table 4. According to the yield of the needle coke and oxidized pitch, the comprehensive utilization rate of the catalytic oil slurry and ethylene tar is 37.43 wt%.

[0070] Comparative Example 1

[0071] In Comparative Example 1, a catalytic oil slurry distillation-hydrogenation-coking combined process route is used. The catalytic oil slurry enters a vacuum distillation device and is separated into a reduced top oil, a middle distillate oil, and a reduced bottom oil. The middle distillate oil enters a hydrogenation reaction unit, and the hydrogenation product is separated to obtain hydrogenation tail oil and hydrogenation light oil. The hydrogenation tail oil enters a 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, of which the coking wax oil returns to the delayed coking unit as a recycle oil. The operating parameters of the hydrogenation reaction unit and the delayed coking unit are listed in Table 5, and the material properties are listed in Table 6. The properties of the needle coke are listed in Table 7. It can be seen from the results that the hydrogenation tail oil has a low aromatic carbon rate, and the needle coke has a low strength.

[0072] Comparative Example 2

[0073] In Comparative Example 2, the full-range ethylene tar is directly fed into an oxidation unit to produce oxidized pitch without any process treatment. The operating parameters are listed in Table 8, and the yield and properties of the oxidized pitch are listed in Table 9. According to the yield of the oxidized pitch, the comprehensive utilization rate of the ethylene tar is 19.55 wt%.

[0074] Comparative Example 3

[0075] In Comparative Example 3, the ethylene tar enters an extraction unit to contact and separate with an extractant to obtain a raffinate phase and an aromatic-rich oil. The catalytic oil slurry and hydrogen gas enter a hydrogenation reaction unit, and the hydrogenation product is separated to obtain hydrogenation tail oil and hydrogenation light oil. The hydrogenation tail oil and the aromatic-rich oil are mixed at a mass ratio of 1:0.08 and sent to a delayed coking unit to produce needle coke. The coking oil gas is separated to obtain coking gas, coking light oil, and coking wax oil, of which the coking wax oil returns to the delayed coking unit as a recycle oil.

[0076] The operating parameters of the extraction unit, hydrogenation reaction unit, and delayed coking unit are listed in Table 10, and the material properties are listed in Table 11.

[0077] The properties of the needle coke are listed in Table 12. Although the needle coke yield was 34.02 wt%, the combined utilization of the catalytic slurry oil and ethylene tar was lower than in the example; from a structural organization perspective, the mosaic structure accounted for 6.2%, which was higher than in the example.

[0078] Table 1 Feedstock properties

[0079] Item Ethylene tar Catalytic slurry oil Ash, wt% 0.021 0.004 Sulfur, wt% 0.02 1.08 Aromatic carbon ratio, mol% 89.1 79.4

[0080] Table 2 Example individual unit operation parameters

[0081]

[0082]

[0083] Table 3 Example 1-2 material properties

[0084]

[0085] Table 4 Needle coke and oxidized pitch properties

[0086]

[0087]

[0088] Based on the total feed amount of catalytic slurry oil and ethylene tar.

[0089] Table 5 Comparative Example 1 individual unit operation parameters

[0090]

[0091] Table 6 Comparative Example 1 individual material properties

[0092]

[0093]

[0094] Table 7 Comparative Example 1 needle coke properties

[0095] Item Comparative Example 1 Yield*, wt% 30.71 Sulfur content, wt% 0.37 Hardgrove grindability index 97 Particle strength, wt% 19.4

[0096] Based on the catalytic slurry oil feed amount.

[0097] Table 8 Comparative Example 2 oxidized unit operation parameters

[0098] Reaction conditions Comparative Example 2 Temperature / °C 311 Time / h 7 Air flow / m 3 • (h-kg) -1 ]]> 0.5 Vacuum absolute pressure / kPa 16 Vacuum time / min 18

[0099] Table 9 Comparative Example 2 oxidized pitch properties

[0100]

[0101]

[0102] Based on ethylene tar feed rate.

[0103] Table 10 Comparative Example 3 Individual unit operation parameters

[0104]

[0105] Table 11 Comparative Example 3 Material properties

[0106]

[0107]

[0108] Table 12 Comparative Example 3 Needle coke properties

[0109] Item Comparative Example 3 Yield*, wt% 34.02 Sulfur, wt% 0.34 Hardgrove grindability index 89 Particle strength, wt% 21.1 Texture structure, % Fibrous 57.6 Flaky 36.2 Mosaic 6.2

[0110] Based on total feed rate of cat oil and ethylene tar.

Claims

1. A co-production process for high softening point bitumen and needle coke, comprising the following steps: (1) Under contact conditions, ethylene tar reacts with the extractant to obtain a raffinate phase and an extract phase. The extract phase enters the extractant recovery unit for separation to obtain regenerated extractant and aromatic oil. The extractant is selected from C3-C4. 12 Alkanes, C3-C 12 One or more of the cycloalkanes; (2) The catalytic slurry, the aromatic oil obtained in step (1), and hydrogen are mixed and fed into the hydrogenation reaction unit. Under the action of the hydrogenation catalyst, a hydrogenation reaction occurs. The hydrogenated liquid phase material obtained from the reaction is separated to obtain hydrogenated light oil and hydrogenated tail oil. The hydrogenation catalyst is a catalyst with hydrodesulfurization function; (3) The hydrotreated tail oil obtained in step (2) enters the delayed coking unit to produce needle coke; (4) The hydrogenated light oil obtained in step (2) enters the polymerization reaction unit. The polymerization product obtained from the reaction is mixed with the raffinate obtained in step (1) and enters the oxidation unit to produce high softening point asphalt.

2. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the reaction temperature between ethylene tar and the extractant is 30℃~110℃.

3. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the reaction temperature between ethylene tar and the extractant is 40℃~80℃.

4. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the ethylene tar and the extractant are in countercurrent contact.

5. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, The extractant in step (1) is selected from C5-C. 12 n-Alkanes, C5-C 12 One or more of the isoalkanes.

6. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The extractant in step (1) is one or more of the following: n-propane, isopropane, n-butane, isobutane, n-pentane, isopentane, n-hexane, isohexane, and n-heptane.

7. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the mass ratio of ethylene tar to extractant is 1:0.5 to 1:

5.

8. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the mass ratio of ethylene tar to extractant is 1:1 to 1:

2.

9. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (1), the sum of the gum and asphaltenes content of the aromatic oil shall not exceed 15 wt%.

10. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, In step (1), the sum of the gum and asphaltenes content of the aromatic oil shall not exceed 12 wt%.

11. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, In step (1), the sum of the gum and asphaltenes content of the aromatic oil shall not exceed 8 wt%.

12. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The ash content of the catalytic oil slurry in step (2) is not higher than 0.01 wt%, and the sulfur content is higher than 0.5 wt%.

13. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The ash content of the catalytic slurry in step (2) is not higher than 0.005 wt%, and the sulfur content is 0.8 wt% to 1.5 wt%.

14. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The mass ratio of catalytic oil slurry to aromatic oil is 1:1 to 1:0.

001.

15. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The mass ratio of catalytic oil slurry to aromatic oil is 1:0.2 to 1:0.

01.

16. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The operating conditions for the hydrogenation reaction in step (2) 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 .

17. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The operating conditions for the hydrogenation reaction in step (2) 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 ~1.5h -1 .

18. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The sulfur content of the hydrogenated liquid phase material obtained in step (2) is not higher than 0.5 wt%.

19. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The sulfur content of the hydrogenated liquid phase material obtained in step (2) is not higher than 0.4 wt%.

20. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (2), the 5% distillation temperature of the hydrotreated tail oil shall not be less than 340°C.

21. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, In step (2), the 5% distillation temperature of the hydrotreated tail oil is 370℃~410℃.

22. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The operating conditions for producing needle coke in step (3) include: the outlet temperature of the heating furnace is 420℃~560℃; the pressure at the top of the coke tower is 0.01MPa~2.5MPa; and the reaction cycle is 10h~72h.

23. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, The operating conditions for producing needle coke in step (3) include: the outlet temperature of the heating furnace is 440℃~530℃; the pressure at the top of the coke tower is 0.2MPa~1.3MPa; and the reaction cycle is 32h~54h.

24. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The hydrotreated tail oil obtained in step (2) 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 recycled back to the delayed coking unit for use.

25. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, The operating conditions of the polymerization reaction unit in step (4) include: reaction temperature of 360℃~460℃, reaction pressure of 0.1MPa~5MPa, and residence time of 3h~20h.

26. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The operating conditions of the 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.

27. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The softening point of the polymer product in step (4) is 70℃~180℃, and the content of quinoline insoluble matter is no more than 2wt%.

28. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The softening point of the polymer product in step (4) is 80℃~120℃, and the content of quinoline insoluble matter is no more than 0.8wt%.

29. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (4), the mass ratio of the polymerization product to the raffinate is 1:0.1 to 1:

3.

30. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (4), the mass ratio of the polymerization product to the raffinate is 1:0.3 to 1:1.

5.

31. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, In step (4), the oxidation unit includes at least one oxidation reactor. The mixture of the polymerization product and the raffinate phase is oxidized in the oxidation reactor by contact with oxygen-containing gas. After the reaction is completed, high softening point asphalt is collected from the bottom of the oxidation reactor.

32. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, In step (4), the oxidation unit includes an oxidation light oil collection system, and the oxidation light oil generated by the oxidation reaction is discharged from the top of the oxidation reactor to the oxidation light oil collection system.

33. The co-production process of high softening point bitumen and needle coke according to claim 1, wherein, The operating conditions for the oxidation reaction in step (4) include: a reaction temperature of 240℃~350℃ and a reaction time of 0.5h~10h.

34. The co-production process of high softening point asphalt and needle coke according to claim 1, wherein, The operating conditions for the oxidation reaction in step (4) include: a reaction temperature of 270℃~335℃ and a reaction time of 1.5h~6h.

35. The co-production process of high softening point bitumen and needle coke according to claim 31, wherein, 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 co-production process of high softening point bitumen and needle coke according to claim 35, wherein, The oxygen content of oxygen-containing gas is 20% to 50% by volume.

37. The co-production process of high softening point bitumen and needle coke according to claim 31, wherein, After the oxidation reaction is completed, a vacuum operation is performed on the oxidation reactor in the oxidation unit, with an absolute pressure of 0-80 kPa and a vacuum time of 1-120 min.

38. The co-production process of high softening point bitumen and needle coke according to claim 31, wherein, After the oxidation reaction is completed, a vacuum operation is performed on the oxidation reactor in the oxidation unit, with an absolute pressure of 0-30 kPa and a vacuum time of 5-30 min.

39. The co-production process of high softening point asphalt and needle coke according to claim 24, wherein, The coking oil is returned to the polymerization reaction unit.

40. A co-production system for high softening point bitumen and needle coke, the system comprising: The extraction unit receives ethylene tar and an extractant. The ethylene tar reacts with the extractant to produce a raffinate phase and an extract phase. The extractant is selected from C3-C4 compounds. 12 Alkanes, C3-C 12 One or more of the cycloalkanes; The extractant recovery unit is used to receive the extract phase from the extraction unit, and after separation, obtain the regenerated extractant and aromatic oil. The hydrogenation reaction unit is used to receive catalytic slurry and aromatic oil from the extractant recovery unit, and to carry out a hydrogenation reaction under the action of hydrogen and hydrogenation catalyst. The hydrogenation catalyst is a catalyst with hydrodesulfurization function; The hydrotreating separation unit is used to receive the hydrotreated liquid phase material obtained from the hydrotreating reaction unit, and after separation, it yields hydrotreated light oil and hydrotreated tail oil. The delayed coking unit is used to receive hydrotreated tail oil to produce needle coke. The coking oil gas generated by the reaction enters the coking separation unit, and after separation, coking gas, coking light oil and coking wax oil are obtained. The polymerization reaction unit is used to receive hydrotreated light oil and obtain the polymerization product after the reaction. The oxidation unit receives the polymerization products from the polymerization reaction unit and the raffinate from the extraction unit, and undergoes an oxidation reaction to produce high softening point asphalt. 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 co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The hydrogenation reaction unit is equipped with at least one hydrogenation reactor, which is one or a combination of fixed-bed reactor, suspended-bed reactor, and fluidized-bed reactor.

42. The co-production system of high softening point bitumen and needle coke according to claim 41, wherein, The hydrogenation reactor is a fixed-bed reactor.

43. The co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The delayed coking unit includes at least one heating furnace, two coke towers and one coking fractionation tower; at least one coke tower is always in the reaction stage and at least one is in the purging and decoking stage.

44. The co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The extraction unit is equipped with at least one extraction tower.

45. The co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The oxidation unit includes at least one oxidation reactor. The mixture of polymerization product and raffinate phase is oxidized in the oxidation reactor by contact with oxygen-containing gas. The oxidized light oil generated by the reaction is discharged from the top of the oxidation reactor. After the reaction is completed, high softening point asphalt is collected from the bottom of the oxidation reactor.

46. ​​The co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The oxidation unit includes an oxidation light oil collection system, through which the oxidation light oil generated in the reaction is discharged from the top of the oxidation reactor to the oxidation light oil collection system.

47. The co-production system of high softening point bitumen and needle coke according to claim 40, wherein, The coking light oil is connected to the polymerization reaction unit via pipeline.

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