A method and apparatus for manufacturing needle coke using a batch feeding method

Abstract

This invention relates to a method and apparatus for manufacturing needle coke using a batch feeding method. According to the invention, needle coke with uniform product quality can be produced. The method for manufacturing needle coke according to the invention includes the step of sequentially adding n feedstock oils to a coking reaction at predetermined time intervals, wherein the aromatic carbon content of the i-th feedstock oil is A (mol%), the aromatic carbon content of the (i+1)-th feedstock oil is B (mol%), the aromatic carbon content of the 1-th feedstock oil is A1 (mol%), and the aromatic carbon content of the n-th feedstock oil is B1 (mol%), then B ≥ A, and B1 is greater than A1.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, and in particular relates to a method and apparatus for manufacturing needle coke using a batch feeding method. Background Technology

[0002] In recent years, my country's needle coke production technology has developed rapidly. In terms of production process, unlike conventional delayed coking, needle coke production usually adopts pressurized, temperature-variable, and high circulation ratio operation. That is to say, within one reaction cycle, the raw material is continuously fed into the coke tower, and the needle coke product is obtained by adjusting parameters such as pressure, temperature, and circulation ratio.

[0003] CN113004924A discloses a needle coke production process in which feedstock oil and vacuum residue are mixed and sent to a coking tower for coking reaction, and the circulation ratio is controlled at 0.15-0.20 during the process to obtain needle coke with a high particle strength coefficient.

[0004] CN103184057A discloses a method for producing needle coke, comprising three steps: (1) feeding fresh raw material into a coking tower at a relatively low temperature; (2) after the first step is completed, increasing the outlet temperature of the heating furnace, mixing the fresh raw material and coking heavy distillate oil, and feeding it into the coking tower; (3) when the coking tower reaches the solidification coke temperature, feeding the coking middle distillate oil generated in the first step into the coking tower at a higher temperature. This method can improve the uniformity of needle coke properties in different parts of the coking tower. Summary of the Invention

[0005] Through diligent research, the inventors of this invention discovered that the time required for the coking reaction to complete varies depending on the aromatic carbon content or polymerization capacity of the raw coking materials. Therefore, by varying the residence time of raw materials with different aromatic carbon contents or polymerization capacities within the coking tower, needle coke of uniform product quality can be produced. According to this invention, the microstructure of needle coke products can be improved, and the formation of short fibers, small flakes, and other structural components can be reduced, resulting in high-quality needle coke. This invention is based on these discoveries.

[0006] The present invention relates in a first aspect to a method for manufacturing needle coke, comprising the step of sequentially adding n (n is an integer greater than or equal to 2, preferably 2-15 or 3-5) feedstock oils to a coking reaction at predetermined time intervals, wherein the aromatic carbon content of the i-th (n-1≥i≥1) feedstock oil is A (in mol%), the aromatic carbon content of the (i+1)-th feedstock oil is B (in mol%), the aromatic carbon content of the 1-th feedstock oil is A1 (in mol%), and the aromatic carbon content of the n-th feedstock oil is B1 (in mol%), then B≥A (preferably B1≥5mol% or B1≥10mol%), and B1>A1 (preferably B1-A1≥10mol% or B1-A1≥20mol%).

[0007] In a second aspect, the present invention relates to an apparatus for manufacturing needle coke, comprising the following units:

[0008] The feedstock oil supply unit is configured to provide n feedstock oils (n is an integer greater than or equal to 2, preferably 2-15 or 3-5), where the aromatic carbon percentage of the i-th (n-1≥i≥1) feedstock oil is A (in mol%), the aromatic carbon percentage of the (i+1)-th feedstock oil is B (in mol%), the aromatic carbon percentage of the 1-th feedstock oil is A1 (in mol%), and the aromatic carbon percentage of the n-th feedstock oil is B1 (in mol%). Then B≥A (preferably BA≥5mol% or BA≥10mol%), and B1>A1 (preferably B1-A1≥10mol% or B1-A1≥20mol%).

[0009] The coking unit is configured to receive the n feedstock oils and cause them to undergo a coking reaction to obtain needle coke.

[0010] The control unit is configured to sequentially feedstock oils from the feedstock oil supply unit into the coking unit at predetermined time intervals.

[0011] Technical effect

[0012] Compared with the prior art, the present invention may have one or more or a combination of the following advantages:

[0013] (1) According to a preferred embodiment, the present invention divides the coking reaction cycle into three stages, which can improve the performance of needle coke. In the first stage, the coking feed is the first raw material (first heavy oil), which contains a large amount of hydrogenation products, has low polymerization capacity, and a long residence time in the coking tower, which can promote the conversion of the first raw material into macromolecules; in the second stage, the coking feed is the second raw material (middle distillate oil), which has an increased aromatic carbon content and enhanced polymerization capacity due to cracking reactions such as side chain breaking, and the time required to form a macromolecular structure is shorter than that of the first raw material; in the third stage, the coking feed is the third raw material (third heavy oil), which has undergone delayed coking reaction, has a higher aromatic carbon content, and provides strong heating capacity for the system, which helps to improve the properties of needle coke. The different molecular structures of the three raw materials result in different residence times in the coking tower, which is beneficial to the uniformity of needle coke product quality.

[0014] (2) According to a preferred embodiment, the inventors of this invention discovered during the research process that catalytic slurry undergoes reactions such as C=C double bond saturation, aromatic ring saturation, and aromatic ring opening during hydrodesulfurization. Compared with catalytic slurry, the cracking activity of catalytic slurry increases after hydrogenation, while the condensation reaction performance decreases. In the subsequent preparation of needle coke, the period from condensation of hydrogenated slurry into macromolecules to the formation of a broad-area mesophase becomes longer, which is not conducive to obtaining high-quality needle coke. In the needle coke manufacturing method and production system of this invention, the heavy component (first heavy oil) obtained by separating the catalytic slurry after hydrogenation is first subjected to a cracking reaction. The aromatics undergo a side-chain breaking reaction, transforming into an aromatic structure with a small amount of short side chains. The cracking products are then fractionated, and the fractions enriched with tricyclic and tetracyclic aromatics are used as raw materials for preparing needle coke.

[0015] (3) According to a preferred embodiment, the needle coke manufacturing method of the present invention makes full use of the aromatics in the catalytic slurry, maximizing the conversion of aromatics into tricyclic and tetracyclic aromatics suitable for needle coke production, thereby improving the needle coke yield. All fractions of the catalytic slurry are hydrogenated. The five-ring and higher aromatics contained in the catalytic slurry undergo hydrogenation, fractionation, and cracking reactions in sequence. After hydrogenation, these five-ring and higher aromatics are converted into tetracyclic aromatics with saturated side chains, or even tricyclic aromatics with saturated side chains. These aromatics are further converted into tetracyclic or tricyclic aromatics with short side chains (ideal components for needle coke feedstock) through cracking reactions, thus maximizing the effective utilization of the five-ring and higher aromatics in the catalytic slurry. In contrast, the prior art generally involves fractionating the catalytic slurry and selecting a suitable fraction for hydrogenation, or selecting a suitable fraction after hydrogenation as feedstock for needle coke production. This results in the inefficient utilization of the five-ring and higher aromatics in the catalytic slurry, making it unsuitable as feedstock for needle coke production. The method of this invention can convert the five-ring and higher-ring aromatics in catalytic oil slurry into needle coke feedstock, improving the effective utilization efficiency of catalytic oil slurry, increasing the yield of needle coke feedstock and needle coke, and enhancing the economic value of catalytic oil slurry. Furthermore, the two-ring aromatics and some three-ring aromatics contained in the first light oil can also be converted into three-ring and four-ring aromatics through condensation reactions, thus becoming high-quality feedstock for needle coke.

[0016] (4) According to a preferred embodiment, the needle coke manufacturing method of the present invention can reduce the heat load of the coking unit. Under the conditions of needle coke preparation, the cracking reaction of aromatic side chain breaking in the hydrogenated slurry is an endothermic reaction. The small molecules generated also carry away a large amount of heat, resulting in a low system temperature. In order to promote the condensation of aromatic molecules into large molecules, it is necessary to continuously increase the outlet temperature of the coking furnace to bring more heat into the coke tower. In the catalytic slurry treatment method and system of the present invention, a separate cracking reaction system is set up. In the second stage of the coking reaction, the side chain breaking reaction of the hydrogenated catalytic slurry is transferred to the cracking reactor. Under suitable temperature, pressure and residence time conditions, aromatic feedstock with short side chains is obtained. Moreover, the injection of steam into the cracking reactor can quickly carry the small molecules generated by cracking out of the reactor, avoiding secondary condensation reactions that occur while they are in the cracking reactor.

[0017] (5) According to a preferred embodiment, the needle coke manufacturing method of the present invention can expand the source of needle coke feedstock by introducing a first feedstock oil and mixing it with a first heavy oil to undergo a molecular structure optimization reaction in the cracking reaction system, and removing saturated hydrocarbons and aromatic side chains in the first feedstock oil in the cracking reaction system; and / or introducing a second feedstock oil to blend with cracking products to improve the aromatic composition of the needle coke feedstock. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a needle coke manufacturing method and production system according to one embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the catalytic oil slurry treatment method in the comparative example. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0021] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0022] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0023] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0024] In the context of this specification, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “over,” “upper,” etc., may be used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” said element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (e.g., rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0025] In the context of this specification, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define a specific position or relative relationship. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0026] In the context of this specification, all numeric values ​​of parameters (e.g., quantities or conditions) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0027] In the context of this specification, catalytic slurry refers to heavy distillate oil produced by catalytic cracking.

[0028] In the context of this specification, polarized light microstructures (coarse fibers, fine fibers, short fibers, large sheets, small sheets, mosaics) are determined by method YB / T 077.

[0029] In the context of this specification, the ash content of the oil is determined by method GB / T 508, the sulfur content by method SH / T0689, the aromatic carbon content by method SH / T0793, and the aromatic hydrocarbon content by method SH / T0659.

[0030] In the context of this specification, the ash content of coke is determined by method GB / T 1429, and the sulfur content is determined by method GB / T24526.

[0031] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this instruction manual are based on weight, and the pressure is gauge pressure.

[0032] In the context of this specification, any two or more embodiments of the present invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0033] According to one embodiment of the present invention, a method for manufacturing needle coke is provided. According to the present invention, the method for manufacturing needle coke is performed in a needle coke manufacturing apparatus described below. Therefore, for details not described in the manufacturing method section, reference can be made directly to the relevant content described below regarding the manufacturing apparatus.

[0034] According to one embodiment of the present invention, the method for manufacturing needle coke includes the step of sequentially adding (feeding) n feedstock oils to a coking reaction at predetermined time intervals. According to the present invention, the order in which these feedstock oils are fed (as detailed below) is crucial for achieving the intended technical effect of the present invention and cannot be arbitrarily adjusted. Furthermore, the feeding can be carried out intermittently or continuously, preferably continuously. Moreover, the predetermined time interval refers to the time difference between the feeding times of one feedstock oil and the feeding of another feedstock oil. Preferably, the feeding time of one feedstock oil begins is the feeding time of the other feedstock oils (if any). According to this preferred embodiment, to make the technical effect of the present invention more significant, the n feedstock oils are preferably added to the coking reaction individually at different times, with substantially no overlap in feeding. Furthermore, the present invention does not particularly limit the specific value of the predetermined time interval, as long as the time interval can effectively separate the feeding times of the n feedstock oils; however, preferred methods are detailed below.

[0035] According to one embodiment of the present invention, n is an integer greater than or equal to 2, preferably 2-15 or 3-5.

[0036] According to one embodiment of the present invention, let the aromatic carbon percentage of the i-th (n-1≥i≥1) feedstock be A (in mol%), and let the aromatic carbon percentage of the (i+1)-th feedstock be B (in mol%), then B≥A. Preferably, BA≥5mol% or BA≥10mol%. If B is less than A, especially if BA<5 mol%, then the aromatic carbon percentages of the two feedstocks are similar, and their cracking / polymerization capabilities are likely to be similar as well.

[0037] According to one embodiment of the present invention, let the aromatic carbon content of the first feedstock oil be A1 (in mol%), and let the aromatic carbon content of the nth feedstock oil be B1 (in mol%), then B1 is greater than A1. Preferably, B1-A1 ≥ 10 mol% or B1-A1 ≥ 20 mol%. When B1-A1 < 10 mol%, the polymerization ability of B1 is insufficient, the process of forming the mesophase is slow, and the effect is poor.

[0038] According to one embodiment of the present invention, the aromatic carbon content of the first feedstock oil is 40 mol%-80 mol% (preferably 55 mol%-75 mol%).

[0039] According to one embodiment of the present invention, the aromatic carbon content of the m-th feedstock oil is 60 mol%-90 mol% (preferably 70 mol%-85 mol%). Here, m is any integer greater than 1 and less than n.

[0040] According to one embodiment of the present invention, the aromatic carbon content of the nth feedstock oil is greater than 75 mol% (preferably 80 mol%-95 mol%).

[0041] According to one embodiment of the present invention, the sulfur content of the i-th (n-1≥i≥1) feedstock oil is not greater than 0.45wt% (preferably not greater than 0.37wt%), the ash content is not greater than 0.05wt% (preferably not greater than 0.01wt%), the 5% distillation temperature is 330℃-430℃ (preferably 360℃-400℃), and the 95% distillation temperature is 470℃-530℃ (preferably 485℃-510℃).

[0042] According to one embodiment of the present invention, the sulfur content of the nth feedstock oil is not greater than 0.55 wt% (preferably not greater than 0.5 wt%), the ash content is not greater than 0.05 wt% (preferably not greater than 0.01 wt%), the 5% distillation temperature is 280℃-380℃ (preferably 310℃-360℃), and the 95% distillation temperature is not greater than 480℃.

[0043] According to one embodiment of the present invention, if the reaction period of the coking reaction is T (in hours), then the predetermined time interval divides the coking reaction into n reaction segments. Preferably, within each reaction segment, the feedstock oil corresponding to that reaction segment is continuously or intermittently added from the start to the end of the reaction time of that reaction segment.

[0044] According to one embodiment of the present invention, within each reaction zone, from the start of the reaction time of that reaction zone until the end, no feedstock oil corresponding to that reaction zone is added.

[0045] According to one embodiment of the present invention, let the reaction period of the coking reaction be T (in hours), then the predetermined time interval divides the coking reaction into n reaction segments. For this purpose, let the reaction time of the first reaction segment be T1 (in hours), the reaction time of the m-th reaction segment (where m is any integer greater than 1 and less than n) be Tm (in hours), and the reaction time of the n-th reaction segment be Tn (in hours). Then, T1 / T = 5%-40% (preferably 10%-25%), Tm / T = 15%-85% (preferably 25%-70%), and Tn / T = 15%-80% (preferably 25%-55%).

[0046] According to one embodiment of the present invention, among the n feedstocks, the first feedstock is a hydrogenation product of catalytic slurry, the nth feedstock is the heavy portion of coking oil gas, and any one of the other feedstocks is a cracking product of the hydrogenation product of the catalytic slurry.

[0047] According to one embodiment of the present invention, n=3. Therefore, the quantity of the feedstock oil is three, namely, a first feedstock oil, a second feedstock oil, and a third feedstock oil. Furthermore, the reaction cycle T of the coking reaction is divided into three reaction segments, namely, a first reaction segment, a second reaction segment, and a third reaction segment, wherein in the first reaction segment, the first feedstock oil is added to the coking reaction; in the second reaction segment, the second feedstock oil is added to the coking reaction; and in the third reaction segment, the third feedstock oil is added to the coking reaction.

[0048] According to one embodiment of the present invention, the method for manufacturing the first feedstock oil includes: catalytic slurry is purified and then enters a hydrotreating system to carry out a hydrotreating reaction under the action of hydrogen and a hydrotreating catalyst; the hydrotreating reaction products are separated to obtain a gaseous stream and a liquid stream; the liquid stream enters a first separation system to obtain a first light oil and a first heavy oil, wherein the first heavy oil is used as the first feedstock oil.

[0049] According to one embodiment of the present invention, the ash content of the catalytic slurry is generally higher than 0.01 wt%, and the sulfur content is generally higher than 0.5 wt%, and sometimes higher than 0.8 wt%. Therefore, if the ash and sulfur content in the catalytic slurry cannot meet the requirements of needle coke feedstock, it needs to be treated.

[0050] According to one embodiment of the present invention, the ash content of the purified slurry is ≤0.008wt%, preferably ≤0.005wt%.

[0051] According to one embodiment of the present invention, the purification treatment is generally a solidification treatment. Here, the solidification treatment can be any one or more of the following methods: filtration, centrifugal sedimentation, and flocculation sedimentation, with filtration being preferred.

[0052] According to one embodiment of the present invention, the core equipment for filtration is a filter, and the filter element can be one or a combination of several of the following: sintered metal powder filter element, metal wire mesh filter element, ceramic membrane filter element, etc., preferably a ceramic membrane filter element.

[0053] According to one embodiment of the present invention, the hydrogenation reaction is carried out in a hydrogenation treatment system. For this purpose, the hydrogenation treatment system includes a reaction unit and a separation unit. The reaction unit is equipped with at least one hydrogenation reactor, which may be selected from one or a combination of several of the following: a fluidized bed reactor, a suspended bed reactor, a slurry bed reactor, and a fixed bed reactor, preferably a fixed bed reactor. The separation unit includes a hot high-pressure separator, a cold high-pressure separator, a hot low-pressure separator, and a cold low-pressure separator, and may also include equipment such as a stripping tower and a fractionation tower.

[0054] According to one embodiment of the present invention, the hydrogenation catalyst can be prepared using methods existing in the art, or using existing commercial catalysts, such as the FZC series hydrogenation catalysts developed by the Dalian Research Institute of Petrochemical Technology, Sinopec. The hydrogenation catalyst generally uses alumina as a support, and the active component is an oxide of Group VIB and / or Group VIII metals, such as oxides of Mo, W, Co, Ni, etc., or a combination of several of these metals.

[0055] According to one embodiment of the present invention, the operating conditions of the hydrogenation reaction are as follows: reaction temperature is 310℃-450℃, preferably 340℃-390℃; reaction pressure is 2MPa-20MPa, preferably 4MPa-8MPa; hydrogen-to-oil volume ratio is 100-2500, preferably 800-1800; and liquid hourly space velocity is 0.1 h⁻¹. -1 -2.0h -1 Preferably 0.6h -1 -1.2h -1 .

[0056] According to one embodiment of the present invention, the liquid phase stream is a liquid phase stream that has separated non-condensable vapors, preferably a liquid phase stream that has separated non-condensable vapors and naphtha fractions.

[0057] According to one embodiment of the present invention, the sulfur content in the liquid phase stream is ≤0.4wt%, preferably ≤0.35wt%.

[0058] According to one embodiment of the present invention, the 5% distillation temperature of the first heavy oil is 330°C-420°C, preferably 360°C-400°C. Correspondingly, the 95% distillation temperature of the first light oil is 310°C-420°C, preferably 340°C-400°C.

[0059] According to one embodiment of the present invention, the first light oil discharge device may either send the oil to a condensation reaction system for processing, or a portion of the oil may be discharged from the device and partially sent to a condensation reaction system for processing.

[0060] According to one embodiment of the present invention, the operating conditions of the condensation reaction system are as follows: reaction temperature of 350℃-530℃, preferably 380℃-450℃; reaction pressure of 0.01MPa-5MPa, preferably 1MPa-3MPa; and residence time of 0.1h-15h, preferably 0.5h-6h. Preferably, the condensation reaction system is provided with at least one fixed-bed reactor, the reactor including at least one inlet and one outlet.

[0061] According to one embodiment of the present invention, the reaction time of the first reaction zone accounts for 5%-40% of the reaction cycle T, preferably 10%-25%. That is, in the first stage, the feed to the coking system is the first feedstock oil, and its feeding time accounts for 5% to 40% of the reaction cycle, preferably 10% to 25%.

[0062] According to one embodiment of the present invention, the reaction time of the second reaction zone accounts for 15%-85% of the reaction cycle T, preferably 25%-70%. That is, in the second stage, the feed to the coking system is the second feedstock oil, and its feeding time accounts for 15% to 85% of the reaction cycle, preferably 25% to 70%.

[0063] According to one embodiment of the present invention, in the third stage, the coking system is fed with the third feedstock oil, and the feeding time accounts for the remainder of the reaction cycle.

[0064] According to one embodiment of the present invention, the reaction cycle of the coking reaction is 24-92 hours (preferably 36-60 hours).

[0065] According to one embodiment of the present invention, the method for manufacturing the second feedstock oil includes: the first feedstock oil (such as the first heavy oil) enters a cracking reaction system, and a cracking reaction occurs in the presence of a carrier gas. The resulting cracking products enter a second separation system, and after separation, a second light oil, a middle distillate oil, and a second heavy oil are obtained, wherein the middle distillate oil is used as the second feedstock oil.

[0066] According to one embodiment of the present invention, the cracking reaction is carried out in a cracking reaction system. For this purpose, the cracking reaction system is equipped with at least one reactor, which may be one or a combination of tubular reactors, tower reactors, and tank reactors, preferably a tower reactor. The reactor includes at least two feed inlets and one discharge outlet, one feed inlet for the first heavy oil and the other feed inlet for the carrier gas.

[0067] According to one embodiment of the present invention, the carrier gas can be one or more of water vapor, nitrogen, and inert gases (such as helium, neon, argon, etc.), preferably water vapor.

[0068] According to one embodiment of the present invention, the operating conditions of the cracking reaction are as follows: the reaction temperature is 380℃-520℃, preferably 420℃-490℃; the reaction pressure is 0.1MPa-5MPa, preferably 0.2MPa-1.0MPa; the residence time is 0.01h-30h, preferably 0.1h-3h; and the oil-gas mass ratio is 100:0.1-100:20, preferably 100:1-100:8.

[0069] According to one embodiment of the present invention, the 5% distillation temperature of the middle distillate oil is 340℃-430℃, preferably 360℃-400℃, and the 95% distillation temperature is 470℃-530℃, preferably 485℃-510℃; the sulfur content is ≤0.43wt%, preferably ≤0.37wt%; and the ash content is ≤0.006wt%, preferably ≤0.004wt%. Correspondingly, the 95% distillation temperature of the second light oil is 330℃-430℃, preferably 350℃-400℃, or the 5% distillation temperature of the second heavy oil is 470℃-540℃, preferably 485℃-520℃.

[0070] According to one embodiment of the present invention, the first feedstock oil and the first auxiliary feedstock oil are fed into the cracking reaction system together. Preferably, the first auxiliary feedstock oil has an ash content of no more than 0.02 wt%, preferably no more than 0.01 wt%, a sulfur content of no more than 0.4 wt%, preferably no more than 0.35 wt%, a tricyclic or higher aromatic hydrocarbon content of no less than 40 wt%, an aromatic carbon content of no less than 40 mol%, preferably 55 mol%-80 mol%, and a distillation range of 300℃-550℃, preferably 330℃-510℃.

[0071] According to one embodiment of the present invention, the first feedstock oil is selected from one or more of catalytic slurry oil, ethylene tar, vacuum gas oil, coking gas oil, deasphalted oil, and hydrotreated oil.

[0072] According to one embodiment of the present invention, the mass ratio of the first auxiliary raw material oil to the first raw material oil is 0:100-50:100, preferably 5:100-20:100.

[0073] According to one embodiment of the present invention, the cracking products are fed into the second separation system together with the second feedstock oil. Preferably, the second feedstock oil has an ash content of no more than 0.02 wt%, more preferably no more than 0.01 wt%, a sulfur content of no more than 0.4 wt%, more preferably no more than 0.35 wt%, and an aromatic hydrocarbon content of 50 wt%-95 wt%, more preferably 65 wt%-90 wt%, wherein the content of tricyclic and higher-order aromatic hydrocarbons is no less than 40 wt%, and the aromatic carbon ratio is no less than 50 mol%, more preferably no less than 75 mol%.

[0074] According to one embodiment of the present invention, the second feedstock oil is selected from one or more of catalytic slurry oil, ethylene tar, vacuum gas oil, coking wax oil, and deasphalted oil.

[0075] According to one embodiment of the present invention, the mass ratio of the second feedstock oil to the cracking product is 0:100-100:10, preferably 5:100-20:100.

[0076] According to one embodiment of the present invention, the cracking products and the products obtained by condensation reaction of the first light oil are introduced into the second separation system for separation.

[0077] According to one embodiment of the present invention, the mass ratio of the cracking product to the product obtained by the condensation reaction of the first light oil is 100:0-100:20, preferably 100:0-100:5.

[0078] According to one embodiment of the present invention, the method for manufacturing the third feedstock oil includes: the coking oil gas generated by the coking reaction enters a third separation system, and after separation, coking gas, third light oil and third heavy oil are obtained, wherein the third heavy oil is used as the third feedstock oil.

[0079] According to one embodiment of the present invention, the 5% distillation temperature of the third heavy oil is 280°C-380°C, preferably 310°C-360°C. Correspondingly, the 95% distillation temperature of the third light oil is 270°C-380°C, preferably 300°C-360°C.

[0080] According to one embodiment of the present invention, the operating conditions for the coking reaction are as follows: the outlet temperature of the heating furnace is 420℃-560℃, preferably 440℃-530℃, and the heating rate is 0.5℃ / h-30℃ / h, preferably 3℃ / h-7℃ / h; the top pressure of the coke tower is 0.01MPa-2.5MPa, preferably 0.2MPa-1.3MPa. The coking reaction can be carried out under constant pressure or variable pressure. If variable pressure operation is used, the pressure switching rate is 0.1MPa / h-5MPa / h. The reaction cycle of the coking reaction is generally 24h-92h, preferably 36h-60h.

[0081] According to one embodiment of the present invention, the coking reaction is carried out in a coking system. For example, the coking system generally includes at least one heating furnace and two coke towers. At least one coke tower is always in the reaction stage, and at least one is in the purging and decoking stage. The reaction conditions of the coking system are as follows: the heating furnace outlet temperature is 420℃-560℃, preferably 440℃-530℃, with a heating rate of 0.5℃ / h-30℃ / h, preferably 3℃ / h-7℃ / h; the coke tower top pressure is 0.01MPa-2.5MPa, preferably 0.2MPa-1.3MPa, and can be operated under constant pressure or variable pressure; if variable pressure operation is used, the pressure change rate is 0.1MPa / h-5MPa / h; the reaction cycle is 10h-72h, preferably 32h-54h; the needle coke generated by the reaction is deposited at the bottom of the tower, and the generated coking oil and gas are discharged from the top of the tower.

[0082] According to one embodiment of the present invention, the aforementioned condensation reaction is carried out in a condensation reaction system. As an example, the reaction conditions of the condensation reaction system are: a reaction temperature of 350℃-530℃, preferably 380℃-450℃; a reaction pressure of 0.01MPa-5MPa, preferably 1MPa-3MPa; and a residence time of 0.1h-15h, preferably 0.5h-6h. The condensation reaction system is equipped with at least one fixed-bed reactor, the reactor including at least one inlet and one outlet.

[0083] According to one embodiment of the present invention, the condensation reaction can be carried out under the action of a condensation catalyst, the condensation catalyst comprising a support and an active component, wherein the support is one or a combination of several selected from kaolin, montmorillonite, alumina, and silica-containing alumina, preferably alumina, and the active component is at least one oxide of a Group IVB and / or Group VIB metal, such as zirconium, tungsten, molybdenum, etc. Based on the weight of the catalyst, the content of the active component is 0.1wt%-50wt%, preferably 5wt%-25wt%. The condensation catalyst can be spherical, cylindrical, cloverleaf, four-leaf, Raschig ring, etc., or a combination of several of these shapes.

[0084] According to one embodiment of the present invention, an apparatus for manufacturing needle coke is also provided. According to the present invention, the apparatus for manufacturing needle coke is specifically designed for carrying out the needle coke manufacturing method described above. Therefore, for details not described in the section on the manufacturing apparatus, please refer directly to the relevant content described in the entire text regarding the manufacturing method.

[0085] According to one embodiment of the present invention, the needle coke manufacturing apparatus includes the following units:

[0086] The feedstock supply unit is configured to provide n (n is an integer greater than or equal to 2) feedstocks. Let the aromatic carbon percentage of the i-th (n-1 ≥ i ≥ 1) feedstock be A (in mol%), the aromatic carbon percentage of the (i+1)-th feedstock be B (in mol%), the aromatic carbon percentage of the 1st feedstock be A1 (in mol%), and the aromatic carbon percentage of the n-th feedstock be B1 (in mol%). Then B ≥ A, and B1 is greater than A1.

[0087] The coking unit is configured to receive the n feedstock oils and cause them to undergo a coking reaction to obtain needle coke.

[0088] The control unit is configured to sequentially feedstock oils from the feedstock oil supply unit into the coking unit at predetermined time intervals.

[0089] According to one embodiment of the present invention, BA ≥ 5 mol% or BA ≥ 10 mol% is preferred.

[0090] According to one embodiment of the present invention, B1-A1 ≥ 10 mol% or B1-A1 ≥ 20 mol% is preferred.

[0091] According to one embodiment of the present invention, in the manufacturing apparatus, n=3, and includes:

[0092] A purification system is used to receive and purify catalytic oil slurry, resulting in purified oil slurry.

[0093] The hydrotreating system receives hydrogen and purified oil slurry from the purification system, and carries out a hydrogenation reaction under the action of a hydrogenation catalyst. The hydrogenation reaction products are separated to obtain a gaseous stream and a liquid stream.

[0094] The first separation system is used to receive the liquid feed stream from the hydrotreatment system and separate it to obtain the first light oil and the first heavy oil.

[0095] A cracking reaction system for receiving first heavy oil and optional first feedstock oil from a first separation system, and reacting them in the presence of a carrier gas;

[0096] The second separation system is used to receive the reaction effluent from the cracking reaction system and an optional second feedstock oil, and separates them to obtain a second light oil, a middle distillate oil and a second heavy oil.

[0097] The coking unit is used to receive first heavy oil (first feedstock oil) from the first separation system, middle distillate oil (second feedstock oil) from the second separation system, and third heavy oil (third feedstock oil) from the third separation system, and after reaction, coking oil gas and needle coke are obtained.

[0098] The third separation system is used to receive the coking oil and gas obtained from the reaction of the coking unit, and separate them to obtain coking gas, third light oil and third heavy oil.

[0099] According to one embodiment of the present invention, the manufacturing apparatus further includes a condensation reaction system for receiving a first light oil from a first separation system. The first light oil enters the condensation reaction system and undergoes a condensation reaction under the action of a condensation catalyst. The reaction effluent obtained from the condensation reaction enters a second fractionation unit and is separated together with the cracking reaction effluent.

[0100] According to one embodiment of the present invention, the first separation system may be one or a combination of several of the following: stripping tower, flash tower, fractionation tower, etc., preferably a fractionation tower.

[0101] According to one embodiment of the present invention, the condensation reaction system is provided with at least one fixed-bed reactor, the reactor including at least one inlet and one outlet.

[0102] According to one embodiment of the present invention, in the needle coke manufacturing apparatus, the purification system adopts any one or more of the following: a filtration device, a centrifugal sedimentation device, a flocculation sedimentation device, etc., preferably a filtration device; the core equipment of the filtration device is a filter, and the filter element can be one or a combination of several of the following: a sintered metal powder filter element, a metal wire mesh filter element, a ceramic membrane filter element, etc., preferably a ceramic membrane filter element.

[0103] According to one embodiment of the present invention, in the needle coke manufacturing apparatus, the hydrogenation treatment system includes a reaction unit and a separation unit. The reaction unit is provided with at least one hydrogenation reactor, which can be selected from one or a combination of several of the following: fluidized bed reactor, suspended bed reactor, slurry bed reactor, fixed bed reactor, etc., preferably a fixed bed reactor. The separation unit includes a hot high-pressure separator, a cold high-pressure separator, a hot low-pressure separator, a cold low-pressure separator, and may also include equipment such as a stripping tower and a fractionation tower.

[0104] According to one embodiment of the present invention, in the needle coke manufacturing apparatus, the first separation system may be one or a combination of several of the following: a stripping tower, a flash tower, a fractionating tower, etc., preferably a fractionating tower.

[0105] According to one embodiment of the present invention, in the needle coke manufacturing apparatus, the cracking reaction system is provided with at least one reactor, which may be at least one of a tubular reactor, a tower reactor, and a tank reactor, preferably a tower reactor. The reactor includes at least two feed inlets and one discharge outlet, one feed inlet for introducing first heavy oil and the other feed inlet for introducing carrier gas.

[0106] According to one embodiment of the present invention, in the needle coke manufacturing apparatus, the second separation system may be one or a combination of several of the following: a stripping tower, a flash tower, a fractionating tower, etc., preferably a fractionating tower.

[0107] According to one embodiment of the invention, in the needle coke manufacturing apparatus, the coking system includes at least one heating furnace, two coke towers, and one fractionation tower. At least one coke tower is always in the reaction stage, and at least one is in the purging and decoking stage.

[0108] A specific embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0109] like Figure 1As shown, the specific process of the needle coke manufacturing method provided by the present invention is as follows: the catalytic slurry 1 first enters the purification system 2 for desolidification and purification treatment. After the treatment, the purified slurry 9 obtained is mixed with hydrogen 11 and enters the hydrogenation treatment system 3. Under the action of the hydrogenation catalyst, the reaction is carried out. The hydrogenation reaction product 10 enters the hydrogenation separation unit 4 for separation. After separation, gas phase material stream 12 and liquid phase material stream 13 are obtained. Liquid feed 13 enters the first separation system 5, where it is separated to obtain first light oil 14 and first heavy oil 15. The first light oil 14 can be directly discharged from the device or enter the condensation reaction system 7 for condensation reaction. The condensation reaction product 16 is sent to the second separation system 6. In the first stage of coking reaction, the first heavy oil 15 enters the coking system 22A / 22B as the first feedstock 25. In the remaining stages of coking reaction, the first heavy oil 15 and any first feedstock oil 27 enter the cracking reaction system 8 for cracking reaction in the presence of carrier gas 17. The reaction effluent 18 obtained from the cracking reaction and any second feedstock oil 26 enter the second separation system 6, where it is separated to obtain second light oil 19, middle distillate oil 20, and second heavy oil 21. The second light oil 19 is discharged from the device or enters the purification treatment system 2 as a diluent to be mixed with catalytic oil slurry 1 for purification treatment. The second heavy oil 21 is discharged from the device. In the second stage of the coking reaction, middle distillate oil 20 enters coking system 22A / 22B as the second feedstock for needle coke production. After the reaction, coking oil and gas 23 and needle coke product 24 are obtained. Coking oil and gas 23 enters the third separation system 30, where it is separated to obtain coking gas 28, third light oil 29, and third heavy oil 30. In the third stage of the coking reaction, third heavy oil 30 enters coking system 22A / 22B as the third feedstock for needle coke production. Example

[0110] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0111] The properties of the catalytic slurry, first feedstock oil, and second feedstock oil used in the embodiments and comparative examples of this invention are shown in Table 1. The hydrogenation catalyst used is the FZC-34BT hydrogenation catalyst developed by the Dalian Research Institute of Petrochemical Technology, Sinopec. The purification system uses a filter, and the carrier gas is steam.

[0112] Example 1

[0113] After purification, the catalytic slurry enters the hydrotreating system. The liquid feed stream obtained from the hydrotreating products is sent to the first separation system, where it is separated into first light oil and first heavy oil. Part of the first heavy oil is used as the first feedstock and sent to the coke tower in the first stage of the coking reaction. Part of the first heavy oil enters the cracking reaction system. The effluent from the cracking reaction enters the second separation system, where it is separated into second light oil, middle distillate oil, and second heavy oil. The middle distillate oil is used as the second feedstock and sent to the coke tower in the second stage of the coking reaction. The needle coke generated in the coking reaction is deposited at the bottom of the tower. The coking gas is sent to the third separation system, where it is separated into coking gas, third light oil, and third heavy oil. The third heavy oil is used as the third feedstock and sent to the coke tower in the third stage of the coking reaction. The conditions for the hydrotreating, cracking, and coking reactions are listed in Table 2, and the feed properties of the three stages of the coking system are listed in Table 3.

[0114] The yield of needle coke based on catalytic oil slurry is listed in Table 4.

[0115] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0116] Example 2

[0117] The difference between Example 2 and Example 1 is that the first feedstock is fed to the coking tower throughout the entire coking reaction cycle, the second feedstock is fed to the coking tower in the second stage of the coking reaction, and the third feedstock is fed to the coking tower in the third stage of the coking reaction. The conditions for hydrotreating, cracking, and coking are listed in Table 2, and the feedstock properties for the three stages of the coking system are listed in Table 6.

[0118] The yield of needle coke based on catalytic oil slurry is listed in Table 4.

[0119] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0120] Example 3

[0121] Example 3 follows the same process as Example 1, with the difference being some operating parameters. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are listed in Table 2, and the feed properties of the three-stage coking system are listed in Table 7.

[0122] The yield of needle coke based on catalytic oil slurry is listed in Table 4.

[0123] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0124] Example 4

[0125] Example 4 follows the same process as Example 1, except for some operating parameters. The conditions for hydrogenation, cracking, and coking are listed in Table 2, and the feed properties of the three stages of the coking system are listed in Table 8.

[0126] The yield of needle coke based on catalytic oil slurry is listed in Table 4.

[0127] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0128] Example 5

[0129] Example 5 follows a similar process to Example 4, except that the first light oil enters the condensation reaction system. The condensation reaction conditions are: reaction temperature 405℃, reaction pressure 1.2MPa, and residence time 2.5h. The condensation catalyst is a cloverleaf structure with alumina as the support and 8wt% ZrO2-3.5wt% MoO2 as the active components. The condensation reaction products enter the second separation system, with a cracking product to condensation product mass ratio of 100:9. The conditions for the hydrotreating, cracking, and coking reactions are listed in Table 2, and the feed properties of the three stages of the coking system are listed in Table 9.

[0130] The yield of needle coke based on catalytic oil slurry is listed in Table 4.

[0131] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0132] Example 6

[0133] Example 6 follows a similar process to Example 1, except that the first feedstock and the first heavy oil are fed into the cracking reaction system at a mass ratio of 7:100. The conditions for the hydrotreating, cracking, and coking reactions are listed in Table 2, and the feed properties for the three stages of the coking system are listed in Table 10.

[0134] The yield of needle coke based on catalytic oil slurry and the first by-product is listed in Table 4.

[0135] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0136] Example 7

[0137] Example 7 follows a similar process to Example 1, except that the second feedstock and cracking products are fed into the cracking reaction system at a mass ratio of 9:100. The conditions for the hydrogenation, cracking, and coking reactions are listed in Table 2, and the feed properties for the three stages of the coking system are listed in Table 11.

[0138] The yield of needle coke based on catalytic oil slurry and second feedstock is listed in Table 4.

[0139] The statistical results of the obtained needle fossil microstructure are listed in Table 5.

[0140] Comparative Example 1

[0141] The specific process of Comparative Example 1 is as follows: Figure 2As shown in the table, the catalytic slurry, after purification, enters a vacuum distillation unit to separate the first middle distillate oil. The first middle distillate oil is sent to a hydrotreating system, and the liquid feed stream obtained from the hydrotreating reaction products is sent to a hydroseparation system to separate the second middle distillate oil. The second middle distillate oil is sent as the first feedstock to the coking tower, where the needle coke produced by the reaction is deposited at the bottom. The coking gas is sent to the coking separation system, and the separated heavy coking oil is used as the second feedstock. The second feedstock oil and the first feedstock oil are returned to the coking tower at a mass ratio of 1:1. The hydrotreating and coking reaction conditions are listed in Table 12, and the feed properties of the coking system are listed in Table 13.

[0142] The yield of needle coke based on catalytic oil slurry is listed in Table 14.

[0143] The statistical results of the obtained needle fossil microstructure are listed in Table 15.

[0144] Comparative Example 2

[0145] After purification, the catalytic slurry enters the hydrotreating system. The liquid feed stream obtained from the hydrotreating products is sent to the first separation system, where it is separated into first light oil and first heavy oil. A portion of the first heavy oil is used as the first feedstock. A portion of the first heavy oil enters the cracking system, and the cracking effluent enters the second separation system, where it is separated into second light oil, middle distillate oil, and second heavy oil. The middle distillate oil is used as the second feedstock. The coking gas generated from the coking reaction is sent to the third separation system, where it is separated into coking gas, third light oil, and third heavy oil. The third heavy oil is used as the third feedstock. The first, second, and third feedstocks are fed to the coking tower in a mass ratio of 2:4:4. The needle coke generated from the coking reaction is deposited at the bottom of the tower. The conditions for the hydrotreating, cracking, and coking reactions are listed in Table 12, and the feed properties for the coking system are listed in Table 16.

[0146] The yield of needle coke based on catalytic oil slurry is listed in Table 14.

[0147] The statistical results of the obtained needle fossil microstructure are listed in Table 15.

[0148] Comparative Example 3

[0149] The three feedstocks were obtained in the same way as in Comparative Example 2, but the feeding stages to the coking tower differed: the third feedstock was fed to the coking tower in the first stage of the coking reaction, the second feedstock in the second stage, and the first feedstock in the third stage. The conditions for the hydrotreating, cracking, and coking reactions are listed in Table 12, and the feedstock properties for the coking system are listed in Table 17.

[0150] The yield of needle coke based on catalytic oil slurry is listed in Table 14.

[0151] The statistical results of the obtained needle fossil microstructure are listed in Table 15.

[0152] Table 1 Properties of Raw Materials

[0153]

[0154] Table 2. Conditions for hydrogenation, cracking, and coking reactions in the examples.

[0155]

[0156] Table 3 Properties of the three feedstock oils in Example 1

[0157]

[0158] Table 4. Needle coke yield in the examples

[0159]

[0160] Table 5. Statistical results of the microstructure of needle foci in the examples.

[0161]

[0162] In Table 5, the proportion of coarse and fine fibers in the embodiments reached more than 60%.

[0163] Table 6 Properties of the three feedstock oils in Example 2

[0164]

[0165] Table 7 Properties of the three feedstock oils in Example 3

[0166]

[0167] Table 8 Properties of the three feedstock oils in Example 4

[0168]

[0169] Table 9 Properties of the three feedstock oils in Example 5

[0170]

[0171] Table 10 Properties of the three feedstock oils in Example 6

[0172]

[0173] Table 11 Properties of the three feedstock oils in Example 7

[0174]

[0175] Table 12 Comparative conditions for hydrogenation, cracking, and coking reactions

[0176]

[0177] Table 13 Properties of Three Feed Oils in Comparative Example 1

[0178]

[0179] Table 14 Comparative yield of needle coke

[0180]

[0181] Table 15 Statistical results of the microstructure of comparative needle coke.

[0182]

[0183] In Table 15, the proportion of coarse and fine fibers in the comparative example is less than 55%.

[0184] Table 16 Properties of Three Feed Oils in Comparative Example 2

[0185]

[0186] Table 17 Properties of Three Feed Oils in Comparative Example 3

[0187]

Claims

1. A method for manufacturing needle coke, comprising the step of sequentially adding n feedstock oils to a coking reaction at predetermined time intervals, where n is an integer greater than or equal to 3, wherein the aromatic carbon content of the i-th feedstock oil is A (mol%), the aromatic carbon content of the (i+1)-th feedstock oil is B (mol%), n-1≥i≥1, the aromatic carbon content of the 1-th feedstock oil is A1 (mol%), and the aromatic carbon content of the n-th feedstock oil is B1 (mol%), then B≥A, and B1 is greater than A1; among the n feedstock oils, the 1-th feedstock oil is a hydrogenation product of catalytic slurry, the n-th feedstock oil is the heavy fraction of coking gas, and any one of the other feedstock oils is a cracking product of the hydrogenation product of the catalytic slurry; the reaction period of the coking reaction is T (hours), the predetermined time interval divides the coking reaction into n reaction segments, and the reaction time of the 1-th reaction segment is T1, the reaction time of the m-th reaction segment is Tm, m is any integer greater than 1 and less than n. Let the reaction time of the nth reaction segment be Tn, then T1 / T = 5%-40%, Tm / T = 15%-85%, and Tn / T = 15%-80%.

2. The manufacturing method according to claim 1, wherein n is 3-15, and / or, BA≥5mol%, and / or, B1-A1≥10mol%, and / or, T1 / T=10%-25%, Tm / T=25%-70%, Tn / T=25%-55%.

3. The manufacturing method according to claim 1, wherein n is 3-5, and / or, BA ≥ 10 mol%, and / or, B1-A1 ≥ 20 mol%.

4. The manufacturing method according to claim 1, wherein the aromatic carbon content of the first raw material oil is 40mol%-80mol%, the aromatic carbon content of the m-th raw material oil is 60mol%-90mol%, where m is any integer greater than 1 and less than n, and the aromatic carbon content of the n-th raw material oil is greater than 75mol%.

5. The manufacturing method according to claim 4, wherein the aromatic carbon content of the first raw material oil is 55 mol%-75 mol%, and / or, the aromatic carbon content of the m-th raw material oil is 70 mol%-85 mol%, and / or, the aromatic carbon content of the n-th raw material oil is 80 mol%-95 mol%.

6. The manufacturing method according to claim 1, wherein the i-th raw material oil has a sulfur content of no more than 0.45 wt%, an ash content of no more than 0.05 wt%, a 5% distillation temperature of 330℃-430℃, a 95% distillation temperature of 470℃-530℃, and a tricyclic or higher aromatic hydrocarbon content of more than 35 wt%, and n-1≥i≥1; wherein the n-th raw material oil has a sulfur content of no more than 0.55 wt%, an ash content of no more than 0.05 wt%, a 5% distillation temperature of 280℃-380℃, a 95% distillation temperature of no more than 480℃, and a tricyclic or higher aromatic hydrocarbon content of more than 40 wt%.

7. The manufacturing method according to claim 6, wherein the i-th feedstock oil has a sulfur content of no more than 0.37 wt%, an ash content of no more than 0.01 wt%, a 5% distillation temperature of 360℃-400℃, a 95% distillation temperature of 485℃-510℃, and a tricyclic or higher aromatic hydrocarbon content of 38-60 wt%, and / or, the n-th feedstock oil has a sulfur content of no more than 0.5 wt%, an ash content of no more than 0.01 wt%, a 5% distillation temperature of 310℃-360℃, a 95% distillation temperature of no more than 480℃, and a tricyclic or higher aromatic hydrocarbon content of 45-65 wt%.

8. The manufacturing method according to claim 1, wherein in each reaction section, the raw material oil corresponding to that reaction section is continuously or intermittently added from the start of the reaction time of that reaction section until the end of the reaction time.

9. The manufacturing method according to claim 8, wherein in each reaction zone, from the start of the reaction time of that reaction zone until the end, no raw material oil corresponding to that reaction zone is added.

10. The manufacturing method according to claim 1, wherein n=3, the quantity of the raw material oil is 3, namely, the first raw material oil, the second raw material oil and the third raw material oil, the reaction cycle T of the coking reaction is divided into 3 reaction segments, namely the first reaction segment, the second reaction segment and the third reaction segment, wherein in the first reaction segment, the first raw material oil is added to the coking reaction, in the second reaction segment, the second raw material oil is added to the coking reaction, and in the third reaction segment, the third raw material oil is added to the coking reaction.

11. The manufacturing method according to claim 10, wherein the manufacturing method of the first raw material oil comprises: After purification, the catalytic slurry is purified and then enters the hydrotreating system. Under the action of hydrogen and a hydrotreating catalyst, a hydrotreating reaction is carried out. The products of the hydrotreating reaction are separated to obtain a gaseous stream and a liquid stream. The liquid stream enters the first separation system to obtain a first light oil and a first heavy oil, wherein the first heavy oil is used as the first feedstock oil.

12. The manufacturing method according to claim 11, wherein the catalytic slurry has an ash content higher than 0.01 wt% and a sulfur content higher than 0.5 wt%.

13. The manufacturing method according to claim 11, wherein the ash content of the purified oil slurry is ≤0.008wt%.

14. The manufacturing method according to claim 11, wherein the purification treatment is a desolidification treatment.

15. The manufacturing method according to claim 14, wherein the desolidification treatment employs any one or more of the following methods: filtration, centrifugal sedimentation, and flocculation sedimentation.

16. The manufacturing method according to claim 11, wherein the operating conditions of the hydrogenation reaction are as follows: reaction temperature of 310℃-450℃, reaction pressure of 2MPa-20MPa, hydrogen-to-oil volume ratio of 100-2500, and liquid hourly space velocity of 0.1 h⁻¹. -1 -2.0h -1 .

17. The manufacturing method according to claim 16, wherein the operating conditions of the hydrogenation reaction are as follows: reaction temperature of 340℃-390℃, reaction pressure of 4MPa-8MPa, hydrogen-to-oil volume ratio of 800-1800, and liquid hourly space velocity of 0.6 h⁻¹. -1 -1.2h -1 .

18. The manufacturing method according to claim 11, wherein the liquid phase stream is a liquid phase stream from which non-condensable gases have been separated, and / or, the sulfur content in the liquid phase stream is ≤0.4wt%.

19. The manufacturing method according to claim 11, wherein the liquid phase stream is a liquid phase stream separated from noncondensable gas and naphtha fraction, and / or, the sulfur content in the liquid phase stream is ≤0.35wt%.

20. The manufacturing method according to claim 11, wherein the 5% distillation temperature of the first heavy oil is 330°C-420°C, and / or the 95% distillation temperature of the first light oil is 310°C-420°C.

21. The manufacturing method of claim 20, wherein the 5% distillation temperature of the first heavy oil is 360°C-400°C, and / or the 95% distillation temperature of the first light oil is 340°C-400°C.

22. The manufacturing method according to claim 11, wherein the first light oil discharge device is either sent to the condensation reaction system for processing, or a portion of the discharge device is sent to the condensation reaction system for processing.

23. The manufacturing method according to claim 22, wherein the operating conditions of the condensation reaction system are: reaction temperature of 350℃-530℃, reaction pressure of 0.01MPa-5MPa, and residence time of 0.1h-15h.

24. The manufacturing method according to claim 22, wherein the operating conditions of the condensation reaction system are: reaction temperature of 380℃-450℃, reaction pressure of 1MPa-3MPa, and residence time of 0.5h-6h.

25. The manufacturing method according to claim 1, wherein the reaction time of the first reaction zone accounts for 5%-40% of the reaction cycle T, and / or, the reaction time of the second reaction zone accounts for 15%-85% of the reaction cycle T.

26. The manufacturing method according to claim 1, wherein the reaction time of the first reaction section accounts for 10%-25% of the reaction cycle T, and / or, the reaction time of the second reaction section accounts for 25%-70% of the reaction cycle T.

27. The manufacturing method according to claim 1, wherein the reaction cycle of the coking reaction is 24-92 hours.

28. The manufacturing method according to claim 1, wherein the reaction cycle of the coking reaction is 36-60 hours.

29. The manufacturing method according to claim 10, wherein the manufacturing method of the second raw material oil comprises: The first feedstock oil enters the cracking reaction system and undergoes a cracking reaction in the presence of carrier gas. The resulting cracking products enter the second separation system and are separated to obtain a second light oil, a middle distillate oil, and a second heavy oil, wherein the middle distillate oil is used as the second feedstock oil.

30. The manufacturing method according to claim 29, wherein the operating conditions of the cracking reaction are as follows: reaction temperature of 380℃-520℃, reaction pressure of 0.1MPa-5MPa, residence time of 0.01h-30h, and oil-gas mass ratio of 100:0.1-100:

20.

31. The manufacturing method according to claim 29, wherein the operating conditions of the cracking reaction are as follows: reaction temperature of 420℃-490℃, reaction pressure of 0.2MPa-1.0MPa, residence time of 0.1h-3h, and oil-gas mass ratio of 100:1-100:

8.

32. The manufacturing method according to claim 29, wherein the 5% distillation temperature of the middle distillate oil is 340℃-430℃, the 95% distillation temperature is 470℃-530℃, the sulfur content is ≤0.43wt%, the ash content is ≤0.006wt%, and / or, the 95% distillation temperature of the second light oil is 330℃-430℃, and / or, the 5% distillation temperature of the second heavy oil is 470℃-540℃.

33. The manufacturing method according to claim 29, wherein the 5% distillation temperature of the middle distillate oil is 360℃-400℃, the 95% distillation temperature is 485℃-510℃, the sulfur content is ≤0.37wt%, the ash content is ≤0.004wt%, and / or, the 95% distillation temperature of the second light oil is 350℃-400℃, and / or, the 5% distillation temperature of the second heavy oil is 485℃-520℃.

34. The manufacturing method according to claim 29, wherein the first feedstock oil and the first auxiliary feedstock oil enter the cracking reaction system together, wherein the first auxiliary feedstock oil has an ash content of not more than 0.02 wt%, a sulfur content of not more than 0.4 wt%, a tricyclic or higher aromatic hydrocarbon content of not less than 40 wt%, an aromatic carbon ratio of not less than 40 mol%, and a distillation range of 300℃-550℃.

35. The manufacturing method according to claim 34, wherein the first feedstock oil has an ash content of not more than 0.01 wt%, a sulfur content of not more than 0.35 wt%, a tricyclic or higher aromatic hydrocarbon content of not less than 40 wt%, an aromatic carbon content of 55 mol%-80 mol%, and a distillation range of 330℃-510℃.

36. The manufacturing method according to claim 34, wherein the first feedstock oil is selected from one or more of catalytic slurry oil, ethylene tar, vacuum gas oil, coking wax oil, deasphalted oil, and hydrotreated oil.

37. The manufacturing method according to claim 34, wherein the mass ratio of the first auxiliary raw material oil to the first raw material oil is 0:100-50:

100.

38. The manufacturing method according to claim 34, wherein the mass ratio of the first auxiliary raw material oil to the first raw material oil is 5:100-20:

100.

39. The manufacturing method according to claim 29, wherein the cracking product enters the second separation system together with the second feedstock oil, wherein the second feedstock oil has an ash content of not more than 0.02 wt%, a sulfur content of not more than 0.4 wt%, an aromatic hydrocarbon content of 50 wt%-95 wt%, wherein the content of tricyclic and higher aromatic hydrocarbons is not less than 40 wt%, and the aromatic carbon ratio is not less than 50 mol.

40. The manufacturing method according to claim 39, wherein the second auxiliary feedstock oil has an ash content of not more than 0.01 wt%, a sulfur content of not more than 0.35 wt%, an aromatic hydrocarbon content of 65 wt%-90 wt%, wherein the content of tricyclic and higher aromatic hydrocarbons is not less than 40 wt%, and the aromatic carbon ratio is not less than 75 mol.

41. The manufacturing method according to claim 39, wherein the second auxiliary feedstock oil is selected from one or more of catalytic slurry oil, ethylene tar, vacuum gas oil, coking wax oil, and deasphalted oil.

42. The manufacturing method according to claim 39, wherein the mass ratio of the second feedstock oil to the cracking product is 0:100-100:

10.

43. The manufacturing method according to claim 39, wherein the mass ratio of the second feedstock oil to the cracking product is 5:100-20:

100.

44. The manufacturing method according to claim 29, wherein the manufacturing method of the first raw material oil comprises: After purification, the catalytic slurry enters the hydrotreating system, where it undergoes a hydrotreating reaction under the action of hydrogen and a hydrotreating catalyst. The hydrotreating products are separated to obtain a gaseous stream and a liquid stream. The liquid stream enters the first separation system to obtain a first light oil and a first heavy oil, wherein the first heavy oil is used as the first feedstock. The cracking products and the products obtained by the condensation reaction of the first light oil enter the second separation system for separation.

45. The manufacturing method according to claim 44, wherein the mass ratio of the cracking product to the product obtained by the condensation reaction of the first light oil is 100:0-100:

20.

46. ​​The manufacturing method according to claim 44, wherein the mass ratio of the cracking product to the product obtained by the condensation reaction of the first light oil is 100:0-100:

5.

47. The manufacturing method according to claim 10, wherein the manufacturing method of the third raw material oil comprises: The coking oil and gas generated by the coking reaction enter the third separation system, and after separation, coking gas, third light oil and third heavy oil are obtained, wherein the third heavy oil is used as the third feedstock oil.

48. The manufacturing method of claim 47, wherein the 5% distillation temperature of the third heavy oil is 280°C-380°C, and / or the 95% distillation temperature of the third light oil is 270°C-380°C.

49. The manufacturing method according to claim 47, wherein the 5% distillation temperature of the third heavy oil is 310°C-360°C, and / or the 95% distillation temperature of the third light oil is 300°C-360°C.

50. The manufacturing method according to claim 1, wherein the operating conditions of the coking reaction are: the outlet temperature of the heating furnace is 420℃-560℃, and the heating rate is 0.5℃ / h-30℃ / h; the top pressure of the coke tower is 0.01MPa-2.5MPa, constant pressure operation or variable pressure operation, and if variable pressure operation is adopted, the variable pressure rate is 0.1MPa / h-5MPa / h; the reaction cycle is 24-92 hours.

51. The manufacturing method according to claim 1, wherein the operating conditions of the coking reaction are: the outlet temperature of the heating furnace is 440℃-530℃, and the heating rate is 3℃ / h-7℃ / h; the top pressure of the coke tower is 0.2MPa-1.3MPa, constant pressure operation or variable pressure operation, and if variable pressure operation is adopted, the variable pressure rate is 0.1MPa / h-5MPa / h; the reaction cycle is 36-60 hours.

52. An apparatus for manufacturing needle coke according to any one of claims 1-51, comprising the following units: The feedstock oil supply unit is constructed to provide n feedstock oils, where n is an integer greater than or equal to 3. Let the aromatic carbon percentage of the i-th feedstock oil be A, in mol%, and let n-1≥i≥1. Let the aromatic carbon percentage of the (i+1)-th feedstock oil be B, in mol%. Let the aromatic carbon percentage of the 1st feedstock oil be A1, in mol%, and let the aromatic carbon percentage of the n-th feedstock oil be B1, in mol%. Then B≥A, and B1 is greater than A1. The coking unit is configured to receive the n feedstock oils and cause them to undergo a coking reaction to obtain needle coke; The control unit is configured to sequentially feedstock oils from the feedstock oil supply unit into the coking unit at predetermined time intervals.

53. The manufacturing apparatus according to claim 52, wherein n=3, and comprising: A purification system is used to receive and purify catalytic oil slurry, resulting in purified oil slurry. The hydrotreating system receives hydrogen and purified oil slurry from the purification system, and carries out a hydrogenation reaction under the action of a hydrogenation catalyst. The hydrogenation reaction products are separated to obtain a gaseous stream and a liquid stream. The first separation system is used to receive the liquid feed stream from the hydrotreatment system and separate it to obtain the first light oil and the first heavy oil. A cracking reaction system for receiving first heavy oil and optional first feedstock oil from a first separation system, and reacting them in the presence of a carrier gas; The second separation system is used to receive the reaction effluent from the cracking reaction system and an optional second feedstock oil, and separates them to obtain a second light oil, a middle distillate oil and a second heavy oil. The coking unit is used to receive first heavy oil from the first separation system, middle distillate oil from the second separation system, and third heavy oil from the third separation system, and reacts to obtain coking oil gas and needle coke. The third separation system is used to receive the coking oil and gas obtained from the reaction of the coking unit, and separate them to obtain coking gas, third light oil and third heavy oil.

54. The manufacturing apparatus according to claim 53, further comprising a condensation reaction system for receiving a first light oil from a first separation system, the first light oil entering the condensation reaction system and undergoing a condensation reaction under the action of a condensation catalyst, the reaction effluent obtained from the condensation reaction entering a second fractionation unit and being separated together with the cracking reaction effluent.

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