Method and apparatus for producing needle coke in batch mode

Abstract

The present invention relates to a method and apparatus for producing needle coke in a batch mode. According to the present invention, needle coke with uniform product quality can be produced. The needle coke production method of the present invention includes a step of sequentially supplying n feedstocks to a coking reaction at predetermined time intervals, wherein the aromatic carbon fraction of the i-th feedstock is A (unit: mol%), the aromatic carbon fraction of the (i+1)-th feedstock is B (unit: mol%), the aromatic carbon fraction of the 1st feedstock is A1 (unit: mol%), and the aromatic carbon fraction of the n-th feedstock is B1 (unit: mol%), and B≧A is satisfied, and B1 is greater than A1.

Description

Detailed Description of the Invention

[0001] (Technical field) The present invention belongs to the technical field of petrochemical industry, and in particular to a method and apparatus for producing needle coke in a batch mode.

[0002] (Background technology) In recent years, China's needle coke production technology has developed rapidly. The needle coke production process differs from traditional delayed coke in that it is typically carried out under pressure, variable temperature, and a large circulation ratio. In other words, within a reaction period, raw materials are continuously fed into the coking tower, and parameters such as pressure, temperature, and circulation ratio are adjusted to obtain needle coke.

[0003] CN113004924A discloses a needle coke production process in which raw material oil is mixed with vacuum residue and then sent to a coking tower for coking reaction, while controlling the circulation ratio to 0.15-0.20, to obtain needle coke with a high particle strength coefficient.

[0004] CN103184057A also discloses a method for producing needle coke, which includes three steps: (1) feeding raw materials into a coking tower at a relatively low temperature; (2) after the first step is completed, increasing the temperature at the outlet of the heating furnace and mixing the raw materials with coked heavy distillate oil, and sending the resulting mixture to the coking tower; and (3) after the temperature reaches the solidification and coke formation temperature in the coking tower, sending the coked middle distillate oil produced in the first step to the coking tower at a relatively high temperature. This method can improve the uniformity of needle coke properties at different parts of the coking tower.

[0005] (Summary of the Invention) As a result of extensive research, the inventors have found that the time required for the coking reaction to be completed varies depending on the coke-forming feedstock having a different aromatic carbon fraction or a different polymerization ability. Therefore, by varying the residence time of feedstocks having different aromatic carbon fractions or different polymerization abilities in the coking tower, needle coke with uniform product quality can be produced. According to the present invention, the microstructure of the needle coke product can be improved, the occurrence of short fibers, small pieces, and other structures can be reduced, and high-quality needle coke can be obtained. The present invention was made based on these findings.

[0006] In a first aspect, the present invention relates to a method for producing needle coke, the method comprising the step of sequentially supplying n feedstocks (n is an integer of 2 or greater, preferably 2 to 15 or 3 to 5) to a coking reaction at predetermined time intervals, wherein, where A (in mol%) is the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock, B (in mol%) is the aromatic carbon fraction of the (i+1)th feedstock, A1 (in mol%) is the aromatic carbon fraction of the first feedstock, and B1 (in mol%) is the aromatic carbon fraction of the n-th feedstock, B≧A (preferably B≧5 mol% or B≧10 mol%) and B1 is greater than A1 (preferably B1−A1≧10 mol% or B1−A1≧20 mol%).

[0007] In a second aspect, the present invention provides a feedstock supply unit configured to supply the following unit: n feedstocks (n is an integer of 2 or more, preferably 2 to 15 or 3 to 5), wherein, when the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock is A (unit: mol%), the aromatic carbon fraction of the (i+1)th feedstock is B (unit: mol%), the aromatic carbon fraction of the 1st feedstock is A1 (unit: mol%), and the aromatic carbon fraction of the n-th feedstock is B1 (unit: mol%), B≧A (preferably B≧A The present invention relates to an apparatus for producing needle coke, comprising: a raw oil supply unit in which B1 is greater than A1 (preferably B1-A1≧10 mol% or B1-A1≧20 mol%); a coking unit configured to receive the n raw oils and subject them to a coking reaction to obtain needle coke; and a control unit configured to sequentially introduce the n raw oils from the raw oil supply unit into the coking unit at predetermined time intervals.

[0008] (Technical effect) Compared with the prior art, the present invention may have one, more or a combination of all of the following advantages: (1) According to a preferred embodiment, the present invention divides the coking reaction period into three stages, thereby improving the properties of needle coke. In the first stage, the coking feedstock is a first feedstock (first heavy oil) that contains a large amount of hydrogenation products and has low polymerization capacity. By extending the residence time of the first feedstock in the coking tower, the conversion of the first feedstock to polymers can be promoted. In the second stage, the coking feedstock is a second feedstock (middle distillate oil) whose molecules have undergone cracking reactions such as side chain scission to increase the aromatic carbon fraction and enhance polymerization capacity, thereby shortening the time required for polymer structure formation compared to the first feedstock. In the third stage, the coking feedstock is a third feedstock (third heavy oil) that has undergone delayed coking reactions, resulting in a higher aromatic carbon fraction and a stronger heat supply capacity to the system, contributing to the improvement of the properties of needle coke. The three raw materials have different molecular structures and different residence times in the coking tower, which is advantageous for uniform quality of needle coke products.

[0009] (2) According to a preferred embodiment, the inventors of the present invention have discovered the following through research. When catalytic cracking slurry oil is hydrodesulfurized, reactions such as saturation of C=C double bonds, saturation of aromatic rings, and ring-opening of aromatic rings occur. Hydrogenated catalytic cracking slurry oil has improved cracking activity compared to catalytic cracking slurry oil, but its condensation reactivity is reduced. In the subsequent preparation of needle coke, the hydrogenated slurry oil requires a long period of time to condense into polymers until a wide mesophase is formed, making it difficult to obtain high-quality needle coke. In the needle coke production method and production system of the present invention, the heavy component (first heavy oil) obtained by separating the hydrogenated catalytic cracking slurry oil is first subjected to a cracking reaction to cleave the side chains of aromatic hydrocarbons and convert them into aromatic hydrocarbon structures with a small amount of short side chains. The product of the cracking reaction is then fractionated, and a fraction rich in three- and four-ring aromatic hydrocarbons is used as the raw material for preparing needle coke.

[0010] (3) According to a preferred embodiment, the needle coke production method of the present invention fully utilizes the aromatic hydrocarbons in the catalytic cracking slurry oil and maximizes the conversion of the aromatic hydrocarbons into three- and four-ring aromatic hydrocarbons suitable for the preparation of needle coke, thereby improving the yield of needle coke. All fractions of the catalytic cracking slurry oil are hydrogenated, and the five or more ring aromatic hydrocarbons contained in the catalytic cracking slurry oil are sequentially subjected to hydrogenation, fractionation, and cracking reactions. The five or more ring aromatic hydrocarbons are converted through the hydrogenation reaction into four-ring aromatic hydrocarbons with saturated side chains or three-ring aromatic hydrocarbons with saturated side chains. These aromatic hydrocarbons are further converted through the cracking reaction into four-ring aromatic hydrocarbons or three-ring aromatic hydrocarbons with short side chains (ideal compositions for needle coke feedstock), thereby making the most effective use of the five or more ring aromatic hydrocarbons in the catalytic cracking slurry oil. In the prior art, catalytic cracking slurry oil was generally fractionated, and then an appropriately selected fraction was used for hydrogenation, or an appropriately selected hydrogenated fraction was used as a feedstock for needle coke production. As a result, the fraction containing aromatic hydrocarbons with five or more rings in the catalytic cracking slurry oil was not effectively utilized and could not be used as a feedstock for needle coke production. The method of the present invention can convert the fraction containing aromatic hydrocarbons with five or more rings in the catalytic cracking slurry oil into a feedstock for needle coke production, thereby improving the efficiency of effective utilization of the catalytic cracking slurry oil, increasing the yield of the feedstock for needle coke production and the yield of needle coke, and improving the economic value of the catalytic cracking slurry oil. Furthermore, some of the bicyclic and tricyclic aromatic hydrocarbons contained in the first light oil can be converted into tricyclic and tetracyclic aromatic hydrocarbons through a condensation reaction, resulting in a high-quality feedstock for needle coke production.

[0011] (4) According to a preferred embodiment, the needle coke production method of the present invention can reduce the heat load on the coking unit. Under the conditions for preparing needle coke, the cracking reaction of hydrogenated slurry oil, such as the side chain cleavage of aromatic hydrocarbons, is a heat-absorbing reaction. The elimination of the resulting low-molecular-weight compounds also absorbs a large amount of heat, causing a decrease in the temperature in the system. To promote the condensation of aromatic hydrocarbon molecules into polymers, the temperature at the outlet of the coking furnace must be constantly increased to introduce more heat into the coking tower. In the catalytic cracking slurry oil treatment method and treatment system of the present invention, a separate cracking reaction system is provided. In the second stage of the coking reaction, the side chain cleavage reaction of the hydrogenated catalytic cracking slurry oil is transferred to a cracking reactor, where an aromatic hydrocarbon feedstock with short side chains is obtained under appropriate conditions of temperature, pressure, and residence time. Furthermore, by injecting steam into the cracking reactor, the low-molecular-weight compounds produced by the cracking reaction can be quickly removed from the reactor, thereby avoiding secondary condensation reactions due to retention in the cracking reactor.

[0012] (5) According to a preferred embodiment, the needle coke production method of the present invention includes introducing a first auxiliary feedstock and mixing it with a first heavy oil to perform a reaction to optimize the molecular structure in the cracking reaction system and remove saturated hydrocarbons and side chains of aromatic hydrocarbons in the first auxiliary feedstock in the cracking reaction system; and / or introducing a second auxiliary feedstock and blending it with the cracked product to improve the aromatic hydrocarbon composition of the needle coke production feedstock, thereby expanding the supply source of the needle coke production feedstock.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a needle coke manufacturing method and production system according to one embodiment of the present invention. FIG. 2 is a schematic diagram of a comparative example of a method for treating catalytic cracking slurry oil.

[0014] (Detailed Description of the Invention) Hereinafter, specific embodiments of the present invention will be described in detail, but it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is specified by the appended claims.

[0015] All publications, patent applications, patent documents and other documents mentioned in this specification are incorporated herein by reference.Unless otherwise defined, all technical and scientific terms used in this specification have the meaning that those skilled in the art commonly understand.In the event of any discrepancy, the definitions in this specification shall prevail.

[0016] When the prefixes "well-known to those skilled in the art," "prior art," or similar expressions are used herein to introduce materials, substances, methods, processes, apparatus, or components, the subject matter introduced by the prefixes includes those that are conventionally used in the art at the time of filing this application, as well as those that are no longer commonly used but would be generally recognized in the art as being applicable for the same purpose.

[0017] Unless expressly stated otherwise, throughout this specification and claims, the term "comprise / include / contain" or variations thereof such as "comprises / includes / contains" or "comprising / including / containing" is understood to include the stated structure or component, but not to exclude other structures or components.

[0018] In the context of this specification, for convenience of explanation, spatial terms such as "lower," "bottom," "below," "upper," "top," "above," and the like 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 terms are intended to encompass other orientations of an object during use or operation in addition to the orientation shown. For example, if a depicted object is turned over, an element depicted as being "below" or "below" another element or feature would then be "above" or "above" that other element or feature. Thus, the exemplary term "lower" can encompass both the orientations of "below" and "above." Objects may have other orientations (e.g., rotated 90 degrees or other orientations), and spatial terms used herein should be interpreted accordingly.

[0019] In the context of this specification, the terms "first," "second," etc. are used to distinguish between two different elements or parts, but are not used to limit a specific location or relative relationship. In other words, in some embodiments, the terms "first," "second," etc. can be read interchangeably.

[0020] In the context of this specification, all numerical values ​​relating to parameters (e.g., quantities or conditions) should in all instances be understood to be modified by the term "about," whether or not "about" actually appears immediately before the numerical value.

[0021] In the context of this specification, catalytic cracking slurry oil refers to heavy distillate oil produced by catalytic cracking reactions.

[0022] In the context of this specification, the polarized microstructure (coarse fibers, fine fibers, short fibers, large pieces, small pieces, mosaics) is measured by the method of YB / T 077.

[0023] In the context of this specification, the ash content of oil products is measured by the method of GB / T 508; the sulfur content of oil products is measured by the method of SH / T 0689; the aromatic carbon fraction of oil products is measured by the method of SH / T 0793; and the aromatic hydrocarbon content of oil products is measured by the method of SH / T 0659.

[0024] In the context of this specification, the ash content of the coke is measured according to the method of GB / T 1429 and the sulfur content of the coke is measured according to the method of GB / T 24526.

[0025] Unless expressly stated otherwise, all percentages, parts, ratios, etc. referred to herein are by weight and pressure refers to gauge pressure.

[0026] In the context of this specification, any two or more embodiments of the present invention can be arbitrarily combined, and the technical solutions thus formed belong to the original disclosure of this specification and are included in the protection scope of the present invention.

[0027] According to one embodiment of the present invention, a method for producing needle coke is provided. According to the present invention, the method for producing needle coke is performed by a needle coke production apparatus described below. Therefore, for the content not described in detail in the production method section, direct reference can be made to the relevant content described in the needle coke production apparatus described below.

[0028] According to one embodiment of the present invention, the method for producing needle coke includes a step of sequentially supplying (injecting) n feedstocks into a coking reaction at a predetermined time interval. The order of the feedstocks (described in detail below) is crucial for achieving the expected technical effects of the present invention and cannot be arbitrarily adjusted. The injection may be performed intermittently or continuously, preferably continuously. The so-called "predetermined time interval" refers to the injection of one feedstock followed by the injection of another feedstock after a certain time has elapsed. The difference in the timing of the injection of the two feedstocks is the time interval. Preferably, the start of injection of one feedstock coincides with the end of injection of the other feedstock (if any). According to this preferred embodiment, to more significantly achieve the technical effects of the present invention, the n feedstocks are preferably supplied to the coking reaction at different times, with the injections essentially not overlapping. Furthermore, the specific value of the predetermined time interval is not particularly limited as long as it effectively separates the injection timings of the n feedstocks, and preferred embodiments thereof will be described in detail below.

[0029] According to one embodiment of the present invention, n is an integer of 2 or more, preferably 2-15 or 3-5.

[0030] According to one embodiment of the present invention, when the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock is A (unit: mol%) and the aromatic carbon fraction of the (i+1)th feedstock is B (unit: mol%), B≧A. Preferably, BA≧5 mol%, or BA≧10 mol%. When B is smaller than A, particularly when BA<5 mol%, the two feedstocks are considered to have similar aromatic carbon contents and similar cracking / polymerization abilities.

[0031] According to one embodiment of the present invention, the aromatic carbon fraction of the first feedstock is A1 (unit: mol%), and the aromatic carbon fraction of the nth feedstock is B1 (unit: mol%), where B1>A1. Preferably, B1-A1≧10 mol% or B1-A1≧20 mol%. If B1-A1<10 mol%, the polymerization ability of B1 is insufficient, resulting in a slow mesophase formation rate and reduced effectiveness.

[0032] According to one embodiment of the present invention, the first feedstock has an aromatic carbon fraction of 40 mol % to 80 mol % (preferably 55 mol % to 75 mol %).

[0033] According to one embodiment of the present invention, the mth feedstock has an aromatic carbon fraction of 60 mol% to 90 mol% (preferably 70 mol% to 85 mol%), where m is any integer greater than 1 and less than n.

[0034] According to one embodiment of the present invention, the nth feedstock has an aromatic carbon fraction of more than 75 mol % (preferably 80 mol % to 95 mol %).

[0035] According to one embodiment of the present invention, the i-th (n-1≧i≧1) feedstock oil has a sulfur content of 0.45 wt% or less (preferably 0.37 wt% or less), an ash content of 0.05 wt% or less (preferably 0.01 wt% or less), a 5% distillation temperature of 330°C to 430°C (preferably 360°C to 400°C), and a 95% distillation temperature of 470°C to 530°C (preferably 485°C to 510°C).

[0036] According to one embodiment of the present invention, the nth feedstock oil has a sulfur content of 0.55 wt% or less (preferably 0.5 wt% or less), an ash content of 0.05 wt% or less (preferably 0.01 wt% or less), a 5% distillation temperature of 280°C to 380°C (preferably 310°C to 360°C), and a 95% distillation temperature of 480°C or less.

[0037] According to one embodiment of the present invention, the coking reaction has a reaction period T (unit: hours), and the coking reaction is divided into n reaction zones by the predetermined time intervals. Preferably, in each reaction zone, the feedstock oil corresponding to the reaction zone is added continuously or intermittently from the start of the reaction in the reaction zone to the end of the reaction in the reaction zone.

[0038] According to one embodiment of the present invention, in each reaction zone, no feedstock oil not corresponding to the reaction zone is added from the start to the end of the reaction in the reaction zone.

[0039] According to one embodiment of the present invention, the coking reaction has a reaction period T (unit: hours), and the coking reaction is divided into n reaction zones by the predetermined time intervals. In this case, the first reaction zone has a reaction time T (unit: hours), the mth reaction zone (m is an integer greater than 1 and less than n) has a reaction time T (unit: hours), and the nth reaction zone has a reaction time T (unit: hours), where T / T = 5% to 40% (preferably 10% to 25%), T / T = 15% to 85% (preferably 25% to 70%), and T / T = 15% to 80% (preferably 25% to 55%).

[0040] According to one embodiment of the present invention, among the n feedstocks, the first feedstock is a hydrogenated product of catalytic cracking slurry oil, the nth feedstock is a heavy fraction of coker oil gas, and any other feedstock is a cracked product of a hydrogenated product of catalytic cracking slurry oil.

[0041] According to one embodiment of the present invention, n is 3. Therefore, the quantities of the feedstocks are three: a first feedstock, a second feedstock, and a third feedstock. The reaction period T of the coking reaction is divided into three reaction zones: a first reaction zone, a second reaction zone, and a third reaction zone. In the first reaction zone, the first feedstock is supplied to the coking reaction, in the second reaction zone, the second feedstock is supplied to the coking reaction, and in the third reaction zone, the third feedstock is supplied to the coking reaction.

[0042] According to one embodiment of the present invention, the method for producing the first feedstock oil includes the steps of: sending a refined slurry oil obtained by refining a catalytic cracking slurry oil to a hydrotreating system, performing a hydrogenation reaction in the presence of hydrogen and a hydrogenation catalyst, separating the obtained hydrogenated product to obtain a gas phase stream and a liquid phase stream, and sending the liquid phase stream to a first separation system to obtain a first light oil and a first heavy oil to be used as the first feedstock oil.

[0043] According to one embodiment of the present invention, the catalytic cracking slurry oil has an ash content typically higher than 0.01 wt% and a sulfur content typically higher than 0.5 wt%, and in some cases higher than 0.8 wt%. Therefore, if the ash and sulfur contents of the catalytic cracking slurry oil do not meet the requirements for use as a feedstock for needle coke production, it must be treated.

[0044] According to one embodiment of the present invention, the ash content of the refined slurry oil does not exceed 0.008 wt%, preferably does not exceed 0.005 wt%.

[0045] According to one embodiment of the present invention, the purification treatment is typically a solid removal treatment, which can be carried out by one or more of the following treatment modes: filtration, centrifugal sedimentation, and flocculation sedimentation, and is preferably carried out by filtration.

[0046] According to one embodiment of the present invention, the core element of the filtration process is a filter, which may be one or a combination of a sintered metal powder filter element, a metal mesh filter element, a ceramic membrane filter element, etc., and is preferably a ceramic membrane filter element.

[0047] According to one embodiment of the present invention, the hydrogenation reaction is carried out in a hydrotreating system. To this end, the hydrotreating system includes a reaction unit and a separation unit. The reaction unit includes at least one hydrogenation reactor. The hydrogenation reactor may be one selected from an ebullated bed reactor, a suspended bed reactor, a slurry bed reactor, a fixed bed reactor, or a combination thereof, and is preferably a fixed bed reactor; the separation unit includes a high-temperature high-pressure separator, a low-temperature high-pressure separator, a high-temperature low-pressure separator, and a low-temperature low-pressure separator, and may also include a stripping column, a fractionating column, etc.

[0048] According to one embodiment of the present invention, the hydrogenation catalyst may be prepared by a method known in the art, or may be prepared by using an existing commercially available catalyst, such as the FZC series hydrogenation catalyst developed by SINOPEC's Dalian Petrochemical Research Institute. The hydrogenation catalyst generally uses alumina as a support and any one or a combination of oxides of Group VIB and / or Group VIII metals, such as Mo, W, Co, and Ni, as an active component.

[0049] According to one embodiment of the present invention, the conditions for carrying out the hydrogenation reaction are as follows: a reaction temperature of 310°C to 450°C, preferably 340°C to 390°C; a reaction pressure of 2 MPa to 20 MPa, preferably 4 MPa to 8 MPa; a hydrogen / oil volume ratio of 100 to 2500, preferably 800 to 1800; and a liquid hourly space velocity of 0.1 h -1 ~2.0h -1 , preferably 0.6h -1 ~1.2h -1 is.

[0050] According to one embodiment of the present invention, said liquid phase stream is a liquid phase stream from which non-condensable gases are separated, preferably from which non-condensable gases and a naphtha fraction are separated.

[0051] According to one embodiment of the present invention, the sulphur content of said liquid phase stream does not exceed 0.4 wt%, preferably does not exceed 0.35 wt%.

[0052] According to one embodiment of the present invention, the 5% distillation temperature of the first heavy oil is 330°C to 420°C, preferably 360°C to 400°C, and the 95% distillation temperature of the first light oil is 310°C to 420°C, preferably 340°C to 400°C.

[0053] According to one embodiment of the present invention, the first light oil is discharged from the unit or sent to a condensation reaction system for processing, or a portion of the first light oil is discharged from the unit and a portion of the first light oil is sent to a condensation reaction system for processing.

[0054] According to one embodiment of the present invention, the condensation reaction system is carried out under the following conditions: reaction temperature: 350°C to 530°C, preferably 380°C to 450°C; reaction pressure: 0.01 MPa to 5 MPa, preferably 1 MPa to 3 MPa; residence time: 0.1 h to 15 h, preferably 0.5 h to 6 h. Preferably, the condensation reaction system is provided with at least one fixed-bed reactor having at least one inlet and one outlet.

[0055] According to one embodiment of the present invention, the reaction time of the first reaction section occupies 5% to 40%, preferably 10% to 25% of the reaction period T. That is, in the first stage, the first feedstock oil is introduced into the coking system, and the introduction time thereof occupies 5% to 40%, preferably 10% to 25% of the reaction period.

[0056] According to one embodiment of the present invention, the reaction time of the second reaction section occupies 15% to 85%, preferably 25% to 70% of the reaction period T. That is, in the second stage, the second feedstock is introduced into the coking system, and the introduction time thereof occupies 15% to 85%, preferably 25% to 70% of the reaction period T.

[0057] According to one embodiment of the present invention, in a third stage, the third feedstock is introduced into a coking system, the introduction time of which occupies the remainder of the reaction period.

[0058] According to one embodiment of the present invention, the reaction period of the coking reaction is 24 hours to 92 hours (preferably 36 hours to 60 hours).

[0059] According to one embodiment of the present invention, the method for producing the second feedstock oil includes the steps of sending the first feedstock oil (e.g., the first heavy oil) to a cracking reaction system, carrying out a cracking reaction in the presence of a carrier gas, sending the resulting cracked product to a second separation system, and obtaining a second light oil, a middle distillate oil used as the second feedstock oil, and a second heavy oil by separation.

[0060] According to one embodiment of the present invention, the cracking reaction is carried out in a cracking reaction system. To this end, the cracking reaction system comprises at least one reactor. The type of reactor may be one of a tubular reactor, a column reactor, a tank reactor, or a combination thereof, and is preferably a column reactor. The reactor comprises at least two inlets and one outlet, one of which is used to introduce the first heavy oil and the other of which is used to introduce a carrier gas.

[0061] According to one embodiment of the present invention, the carrier gas may be one or more of water vapor, nitrogen gas, and inert gas (e.g., helium gas, neon gas, argon gas, etc.), and is preferably water vapor.

[0062] According to one embodiment of the present invention, the conditions for carrying out the cracking reaction are a reaction temperature of 380°C to 520°C, preferably 420°C to 490°C, a reaction pressure of 0.1 MPa to 5 MPa, preferably 0.2 MPa to 1.0 MPa, a residence time of 0.01 h to 30 h, preferably 0.1 h to 3 h, and a mass ratio of oil to steam of 100:0.1 to 100:20, preferably 100:1 to 100:8.

[0063] According to one embodiment of the present invention, the middle distillate oil has a 5% distillation temperature of 340°C to 430°C, preferably 360°C to 400°C, a 95% distillation temperature of 470°C to 530°C, preferably 485°C to 510°C, a sulfur content of not more than 0.43 wt%, preferably not more than 0.37 wt%, and an ash content of not more than 0.006 wt%, preferably not more than 0.004 wt%. The second light oil has a 95% distillation temperature of 330°C to 430°C, preferably 350°C to 400°C, or the second heavy oil has a 5% distillation temperature of 470°C to 540°C, preferably 485°C to 520°C.

[0064] According to one embodiment of the present invention, the first feedstock is sent to the cracking reaction system together with a first auxiliary feedstock. Preferably, the first auxiliary feedstock has an ash content of 0.02 wt% or less, preferably 0.01 wt% or less, a sulfur content of 0.4 wt% or less, preferably 0.35 wt% or less, a content of aromatic hydrocarbons with three or more rings of 40 wt% or more, an aromatic carbon fraction of 40 mol% or more, preferably 55 mol% to 80 mol%, and a distillation range of 300°C to 550°C, preferably 330°C to 510°C.

[0065] According to one embodiment of the present invention, the first auxiliary feedstock is one or more selected from catalytic cracking slurry oil, ethylene tar, vacuum gas oil, coker gas oil, deasphalted oil and hydrogenation product oil.

[0066] According to one embodiment of the present invention, the mass ratio of the first auxiliary feedstock to the first feedstock is 0:100 to 50:100, preferably 5:100 to 20:100.

[0067] According to one embodiment of the present invention, the cracked product is sent to the second separation system together with a second auxiliary feedstock oil. Preferably, the second auxiliary feedstock oil has an ash content of 0.02 wt% or less, preferably 0.01 wt% or less, a sulfur content of 0.4 wt% or less, preferably 0.35 wt% or less, an aromatic hydrocarbon content of 50 wt% to 95 wt%, preferably 65 wt% to 90 wt%, a content of aromatic hydrocarbons with three or more rings of 40 wt% or more, and an aromatic carbon fraction of 50 mol% or more, preferably 75 mol% or more.

[0068] According to one embodiment of the present invention, the second auxiliary feedstock is one or more of catalytic cracking slurry oil, ethylene tar, vacuum gas oil, coker gas oil and deasphalted oil.

[0069] According to one embodiment of the present invention, the mass ratio of the second co-feedstock to the cracked product is 0:100 to 100:10, preferably 5:100 to 20:100.

[0070] According to one embodiment of the present invention, the cracked product is sent to the second separation system together with the condensation reaction product of the first light oil and separated therein.

[0071] According to one embodiment of the present invention, the mass ratio of the cracked product to the condensation reaction product of the first light oil is 100:0 to 100:20, preferably 100:0 to 100:5.

[0072] According to one embodiment of the present invention, the method for producing the third feedstock oil includes a step of sending the coker oil gas produced by the coking reaction to a third separation system, and obtaining coker gas, a third light oil, and a third heavy oil to be used as the third feedstock oil by separation.

[0073] According to one embodiment of the present invention, the 5% distillation temperature of the third heavy oil is 280°C to 380°C, preferably 310°C to 360°C. At the same time, the 95% distillation temperature of the third light oil is 270°C to 380°C, preferably 300°C to 360°C.

[0074] According to one embodiment of the present invention, the conditions for carrying out the coking reaction include a temperature at the outlet of the heating furnace of 420°C to 560°C, preferably 440°C to 530°C, a temperature rise rate of 0.5°C / h to 30°C / h, preferably 3°C / h to 7°C / h, and a pressure at the top of the coking tower of 0.01 MPa to 2.5 MPa, preferably 0.2 MPa to 1.3 MPa. The coking reaction may be carried out under constant pressure or variable pressure. When carried out under variable pressure, the pressure change rate is 0.1 MPa / h to 5 MPa / h. The reaction period of the coking reaction is usually 24 hours to 92 hours, preferably 36 hours to 60 hours.

[0075] According to one embodiment of the present invention, the coking reaction is carried out in a coking system. For example, the coking system typically includes at least one heating furnace and two coking towers. At least one of the coking towers is in the reaction stage and at least one is in the purge and decoking stage. The reaction conditions of the coking system are as follows: That is, the temperature at the outlet of the heating furnace is 420°C to 560°C, preferably 440°C to 530°C, and the heating rate is 0.5°C / h to 30°C / h, preferably 3°C / h to 7°C / h; the pressure at the top of the coking tower is 0.01MPa to 2.5MPa, preferably 0.2MPa to 1.3MPa, and the reaction may be carried out under constant pressure or under variable pressure. If carried out under variable pressure, the pressure change rate is 0.1MPa / h to 5MPa / h; the reaction period is 10 hours to 72 hours, preferably 32 hours to 54 hours; the needle coke produced by the reaction is deposited at the bottom of the coking tower, and the produced coker oil gas is discharged from the top of the coking tower.

[0076] According to one embodiment of the present invention, the condensation reaction is carried out in a condensation reaction system. For example, the reaction conditions of the condensation reaction system include a reaction temperature of 350°C to 530°C, preferably 380°C to 450°C, a reaction pressure of 0.01 MPa to 5 MPa, preferably 1 MPa to 3 MPa, and a residence time of 0.1 h to 15 h, preferably 0.5 h to 6 h. The condensation reaction system includes at least one fixed-bed reactor having at least one inlet and one outlet.

[0077] According to one embodiment of the present invention, the condensation reaction may be carried out in the presence of a condensation catalyst. The condensation catalyst includes a support and an active component. The support may be one or a combination of two or more of kaolin, montmorillonite, alumina, and silicon-containing alumina, preferably alumina. The active component may be at least one oxide of a Group IVB and / or Group VIB metal, such as an oxide of a metal such as zirconium, tungsten, or molybdenum. The content of the active component is 0.1 wt% to 50 wt%, preferably 5 wt% to 25 wt%, based on the weight of the catalyst. The shape of the condensation catalyst may be one or a combination of spherical, cylindrical, three-leaf clover, four-leaf clover, Raschig ring, etc.

[0078] According to one embodiment of the present invention, there is also provided an apparatus for producing needle coke, which is used to carry out the above-described method for producing needle coke. Therefore, for the content not described in detail in the section on the apparatus for producing needle coke, direct reference can be made to the corresponding content of the production method described throughout the specification.

[0079] According to one embodiment of the present invention, the needle coke manufacturing apparatus comprises: a feedstock supply unit configured to supply n feedstocks (n is an integer of 2 or greater), wherein, when the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock is A (unit: mol%), the aromatic carbon fraction of the (i+1)th feedstock is B (unit: mol%), the aromatic carbon fraction of the first feedstock is A1 (unit: mol%), and the aromatic carbon fraction of the n-th feedstock is B1 (unit: mol%), B≧A and B1 is greater than A1; a coking unit configured to receive the n feedstocks and perform a coking reaction thereon to obtain needle coke; a control unit configured to sequentially send the n feedstocks from the feedstock supply unit to the coking unit at predetermined time intervals.

[0080] According to one embodiment of the present invention, preferably BA≧5 mol % or BA≧10 mol %.

[0081] According to one embodiment of the present invention, preferably, B1-A1≧10 mol % or B1-A1≧20 mol %.

[0082] According to one embodiment of the present invention, in the needle coke production apparatus, n is 3, The needle coke production apparatus includes a refining system used to receive and refine catalytic cracking slurry oil to obtain refined slurry oil; a hydrotreating system adapted to receive hydrogen and the refined slurry oil from the refining system, to carry out a hydrogenation reaction in the presence of a hydrogenation catalyst, and to separate the resulting hydrogenated product to obtain a gas phase stream and a liquid phase stream; a first separation system adapted to receive the liquid phase stream from the hydrotreating system and separate it to obtain a first light oil and a first heavy oil; a cracking reaction system that receives the first heavy oil from the first separation system and, optionally, the first auxiliary feedstock, and is used to carry out a reaction in the presence of a carrier gas; a second separation system for receiving the reaction effluent from the cracking reaction system and, optionally, a second auxiliary feedstock, and for separating the reaction effluent into a second light oil, a middle distillate oil, and a second heavy oil; a coking unit used for receiving the first heavy oil (first feedstock) from the first separation system, the middle distillate oil (second feedstock) from the second separation system, and the third heavy oil (third feedstock) from the third separation system, reacting them, and obtaining coker oil gas and needle coke; and a third separation system that receives the coker oil gas obtained after the reaction from the coking unit and separates it to obtain coker gas, a third light oil, and a third heavy oil.

[0083] According to one embodiment of the present invention, the needle coke production apparatus further includes a condensation reaction system for receiving the first light oil from the first separation system. The first light oil is sent to the condensation reaction system and undergoes a condensation reaction in the presence of a condensation catalyst. The reaction effluent obtained by the condensation reaction is sent to a second separation unit and separated together with the reaction effluent obtained by the cracking reaction.

[0084] According to one embodiment of the present invention, the first separation system may be one or a combination of a stripping column, a flash distillation column, a fractionation column, etc., preferably a fractionation column.

[0085] According to one embodiment of the present invention, the condensation reaction system comprises at least one fixed-bed reactor comprising at least one inlet and one outlet.

[0086] According to one embodiment of the present invention, in the needle coke production apparatus, the refining system uses one or more of a filtration device, a centrifugal sedimentation device, a flocculation sedimentation device, etc., preferably a filtration device; the core element of the filtration device is a filter. The filter element may be one of a sintered metal powder filter element, a metal mesh filter element, a ceramic membrane filter element, etc., or a combination thereof, preferably a ceramic membrane filter element.

[0087] According to one embodiment of the present invention, in the needle coke production apparatus, the hydrotreating system includes a reaction unit and a separation unit, and the reaction unit includes at least one hydrotreating reactor. The hydrotreating reactor may be one or a combination of a bubbling bed reactor, a suspended bed reactor, a slurry bed reactor, and a fixed bed reactor, and is preferably a fixed bed reactor. The separation unit includes a high-temperature high-pressure separator, a low-temperature high-pressure separator, a high-temperature low-pressure separator, and a low-temperature low-pressure separator, and may include a stripping tower, a fractionating tower, etc.

[0088] According to one embodiment of the present invention, in the needle coke production apparatus, the first separation system may be one of a stripping tower, a flash distillation tower, a fractional distillation tower, etc., or a combination thereof, and is preferably a fractional distillation tower.

[0089] According to one embodiment of the present invention, in the needle coke production apparatus, the cracking reaction system includes at least one reactor. The reactor may be at least one of a tubular reactor, a column reactor, and a tank reactor, and is preferably a column reactor. The reactor has at least two inlets and one outlet, one of which is used to introduce the first heavy oil and the other of which is used to introduce a carrier gas.

[0090] According to one embodiment of the present invention, in the needle coke production apparatus, the second separation system may be one of a stripping tower, a flash distillation tower, a fractional distillation tower, etc., or a combination thereof, and is preferably a fractional distillation tower.

[0091] According to one embodiment of the present invention, in the needle coke production apparatus, the coking system includes at least one heating furnace, two coking towers, and one fractionating tower, at least one of which is always in the reaction stage and at least one of which is always in the purge and decoking stage.

[0092] Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0093] As shown in Figure 1, the specific steps of the needle coke production method provided by the present invention are as follows: First, catalytic cracking slurry oil 1 is sent to a refining treatment system 2 for refining treatment to remove solids. The refined slurry oil 9 obtained by the treatment is mixed with hydrogen gas 11, and the mixture is sent to a hydrotreating system 3 for reaction in the presence of a hydrogenation catalyst. The obtained hydrogenated product 10 is sent to a hydrogenated product separation unit 4 for separation, yielding a gas phase stream 12 and a liquid phase stream 13. The liquid phase stream 13 is sent to the first separation system 5, where it is separated to obtain a first light oil 14 and a first heavy oil 15; the first light oil 14 can be discharged directly from the device or sent to the condensation reaction system 7 for condensation reaction, and the resulting condensation reaction product 16 can be sent to the second separation system 6; in the first stage of the coking reaction, the first heavy oil 15 is sent to the coking system 22A / 22B as the first feedstock 25; in other stages of the coking reaction, the first heavy oil 15 and optionally a first auxiliary feedstock 27 are sent to the cracking reaction system 8 to react with the carrier gas 17, and the reaction effluent 18 obtained by the cracking reaction and optionally a second auxiliary feedstock 26 are sent to the second separation system 6 to be separated to obtain a second light oil 19, a middle distillate oil 20, and a second heavy oil 21. The second light oil 19 is discharged from the unit or sent to the refining system 2 as a diluent and mixed with the catalytic cracking slurry oil 1 for further refining; the second heavy oil 21 is discharged from the unit. In the second stage of the coking reaction, the middle distillate oil 20 is sent to the coking system 22A / 22B as a second feedstock for producing needle coke, where it is reacted to produce coker oil gas 23 and needle coke 24. The coker oil gas 23 is sent to the third separation system 30, where it is separated to produce coker gas 28, third light oil 29, and third heavy oil 30. In the third stage of the coking reaction, the third heavy oil 30 is sent to the coking system 22A / 22B as a third feedstock for producing needle coke.

[0094] <Example> The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0095] The feedstock characteristics of the catalytic cracking slurry oil, first auxiliary feedstock, and second auxiliary feedstock used in the examples and comparative examples according to the present invention are shown in Table 1. The hydrogenation catalyst used was the FZC-34BT hydrogenation catalyst developed by SINOPEC's Dalian Petrochemical Research Institute. The purification system used a filter, and steam was used as the carrier gas.

[0096] Example 1 The refined catalytic cracking slurry oil was sent to a hydrotreating system. The liquid phase stream obtained by separating the hydrotreated product was sent to a first separation system to separate into a first light oil and a first heavy oil; a portion of the first heavy oil was used as the first feedstock and sent to a coking tower in the first stage of the coking reaction. Another portion of the first heavy oil was sent to a cracking reaction system, and the resulting cracking reaction effluent was sent to a second separation system to separate into a second light oil, a middle distillate oil, and a second heavy oil. The middle distillate oil was used as the second feedstock and sent to a coking tower in the second stage of the coking reaction; the needle coke produced by the coking reaction was deposited at the bottom of the tower; the coker oil gas was sent to a third separation system to separate into coker gas, a third light oil, and a third heavy oil. The third heavy oil was used as the third feedstock and sent to a coking tower in the third stage of the coking reaction. The conditions for the hydrogenation, cracking and coking reactions are shown in Table 2, and the characteristics of the feedstocks fed into the three stages of the coking system are shown in Table 3.

[0097] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 4.

[0098] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0099] Example 2 Example 2 was carried out in the same manner as Example 1, except that the first feedstock was fed to the coking tower for the entire duration of the coking reaction, the second feedstock was fed to the coking tower in the second stage of the coking reaction, and the third feedstock was fed to the coking tower in the third stage of the coking reaction. The conditions for the hydrogenation, cracking, and coking reactions are shown in Table 2, and the properties of the feedstocks fed to the three stages of the coking system are shown in Table 6.

[0100] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 4.

[0101] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0102] Example 3 Example 3 was carried out in the same manner as Example 1, except for some operational parameters. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 2, and the characteristics of the feedstocks fed into the three stages of the coking system are shown in Table 7.

[0103] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 4.

[0104] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0105] Example 4 Example 4 was carried out in the same manner as Example 1, except for some operational parameters. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 2, and the characteristics of the feedstocks fed into the three stages of the coking system are shown in Table 8.

[0106] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 4.

[0107] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0108] Example 5 In Example 5, the first light oil was sent to a condensation reaction system under the following conditions: a reaction temperature of 405°C, a reaction pressure of 1.2 MPa, and a residence time of 2.5 hours; the condensation catalyst was an alumina support, an active component was 8 wt% ZrO2-3.5 wt% MoO2, and had a three-leaf clover structure. The condensation reaction product was sent to a second separation system, and the mass ratio of the cracked product to the condensation reaction product was 100:9. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 2, and the properties of the feedstocks fed to the three stages of the coking system are shown in Table 9.

[0109] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 4.

[0110] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0111] Example 6 Example 6 was carried out in the same manner as Example 1, except that the first auxiliary feedstock and the first heavy oil were fed to the cracking reaction system in a mass ratio of 7:100. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 2, and the properties of the feedstocks fed to the three stages of the coking system are shown in Table 10.

[0112] Table 4 shows the needle coke yield relative to the catalytic cracking slurry oil and the first auxiliary feedstock.

[0113] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0114] Example 7 Example 7 was carried out in the same manner as Example 1, except that the second auxiliary feedstock and the cracked product were fed to the cracking reaction system in a mass ratio of 9:100. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 2, and the properties of the feedstocks fed to the three stages of the coking system are shown in Table 11.

[0115] Table 4 shows the needle coke yield relative to the catalytic cracking slurry oil and the second auxiliary feedstock.

[0116] The microstructural analysis results of the obtained needle coke are shown in Table 5.

[0117] (Comparative Example 1) The specific procedure for Comparative Example 1 is shown in Figure 2. The refined catalytic cracking slurry oil was sent to a vacuum distillation unit and separated to obtain a first middle distillate oil. The first middle distillate oil was sent to a hydrotreating system, and the resulting hydrogenated product was separated to obtain a liquid phase stream. This liquid phase stream was sent to a hydroseparation system and separated to obtain a second middle distillate oil. The second middle distillate oil was sent to a coking tower as the first feedstock, and the needle coke produced by the reaction was deposited at the bottom of the tower. The resulting coker oil gas was sent to a coking separation system, and the separated coke heavy oil was used as the second feedstock. This second feedstock and the first feedstock were returned to the coking tower in a mass ratio of 1:1. Table 12 shows the conditions for the hydrotreating reaction and coking reaction, and Table 13 shows the characteristics of the feedstock fed to the coking system.

[0118] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 14.

[0119] The microstructural analysis results of the obtained needle coke are shown in Table 15.

[0120] (Comparative Example 2) The refined catalytic cracking slurry oil was sent to a hydrotreating system. The hydrotreated product was separated to obtain a liquid stream. This liquid stream was sent to a first separation system, where it was separated to obtain a first light oil and a first heavy oil. A portion of the first heavy oil was used as the first feedstock; a portion of the first heavy oil was sent to a cracking reaction system. The resulting cracking reaction effluent was sent to a second separation system, where it was separated to obtain a second light oil, a middle distillate oil, and a second heavy oil. The middle distillate oil was used as the second feedstock. The coker oil gas produced by the coking reaction was sent to a third separation system, where it was separated to obtain coker gas, a third light oil, and a third heavy oil. The third heavy oil was used as the third feedstock. The first feedstock, the second feedstock, and the third feedstock were sent to a coking tower in a mass ratio of 2:4:4, and the needle coke produced by the coking reaction was deposited at the bottom of the tower. The conditions for the hydrogenation reaction, cracking reaction and coking reaction are shown in Table 12, and the properties of the raw materials fed into the coking system are shown in Table 16.

[0121] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 14.

[0122] The microstructural analysis results of the obtained needle coke are shown in Table 15.

[0123] (Comparative Example 3) The three feedstocks were obtained in the same manner as in Comparative Example 2, except that the steps of feeding the three feedstocks to the coking tower were as follows: in the first stage of the coking reaction, the third feedstock was fed to the coking tower, in the second stage of the coking reaction, the second feedstock was fed to the coking tower, and in the third stage of the coking reaction, the first feedstock was fed to the coking tower. The conditions for the hydrogenation reaction, cracking reaction, and coking reaction are shown in Table 12, and the properties of the feedstocks fed to the coking system are shown in Table 17.

[0124] The yield of needle coke relative to catalytic cracking slurry oil is shown in Table 14.

[0125] The microstructural analysis results of the obtained needle coke are shown in Table 15.

[0126]

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table 11

Table 12

Table 13

Table 14

Table 15

[0127] [Figure 1] 1 is a schematic diagram of a needle coke manufacturing method and production system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a catalytic cracking slurry oil treatment method in a comparative example.

Claims

1. A method for producing needle coke, comprising: The method includes a step of sequentially supplying n feedstocks (n is an integer of 2 or more, preferably 2 to 15 or 3 to 5) to a coking reaction at predetermined time intervals, where A (mol%) is the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock, B (mol%) is the aromatic carbon fraction of the (i+1)th feedstock, A1 (mol%) is the aromatic carbon fraction of the 1st feedstock, and B1 (mol%) is the aromatic carbon fraction of the nth feedstock, B≧A (preferably B−A≧5 mol% or B−A≧10 mol%) and B1 is greater than A1 (preferably B1−A1≧10 mol% or B1−A1≧20 mol%); Method for producing needle coke.

2. the aromatic carbon fraction of the first feedstock is 40 mol% to 80 mol% (preferably 55 mol% to 75 mol%); the aromatic carbon fraction of the mth feedstock (m is an arbitrary integer greater than 1 and less than n) is 60 mol% to 90 mol% (preferably 70 mol% to 85 mol%); The method according to claim 1, wherein the aromatic carbon fraction of the nth feedstock is greater than 75 mol% (preferably 80 mol% to 95 mol%).

3. The i-th (n-1 ≧ i ≧ 1) feedstock oil is The sulfur content is 0.45 wt% or less (preferably 0.37 wt% or less), The ash content is 0.05 wt% or less (preferably 0.01 wt% or less), 5% distillation temperature is 330°C to 430°C (preferably 360°C to 400°C), 95% distillation temperature is 470°C to 530°C (preferably 485°C to 510°C), The content of aromatic hydrocarbons having three or more rings is more than 35 wt % (preferably 38 wt % to 60 wt %), The n-th raw material oil is The sulfur content is 0.55 wt% or less (preferably 0.5 wt% or less), The ash content is 0.05 wt% or less (preferably 0.01 wt% or less), 5% distillation temperature is 280°C to 380°C (preferably 310°C to 360°C), The 95% distillation temperature is 480°C or less, The method according to claim 1, wherein the content of aromatic hydrocarbons having three or more rings is more than 40 wt % (preferably 45 wt % to 65 wt %).

4. When the reaction period of the coking reaction is T (unit: hour), the coking reaction is divided into n reaction sections by the predetermined time intervals, 2. The production method according to claim 1, wherein in each reaction zone, the feedstock oil corresponding to the reaction zone is added continuously or intermittently from the start of the reaction in the reaction zone to the end of the reaction in the reaction zone.

5. 5. The method according to claim 4, wherein in each reaction zone, no feedstock oil not corresponding to the reaction zone is added from the start to the end of the reaction in the reaction zone.

6. When the reaction period of the coking reaction is T (unit: hour), the coking reaction is divided into n reaction sections by the predetermined time intervals, The production method according to claim 1, wherein the reaction time of the first reaction section is T1 (unit: hour), the reaction time of the mth reaction section (m is an arbitrary integer greater than 1 and less than n) is Tm (unit: hour), and the reaction time of the nth reaction section is Tn (unit: hour), T1 / T = 5% to 40% (preferably 10% to 25%), Tm / T = 15% to 85% (preferably 25% to 70%), and Tn / T = 15% to 80% (preferably 25% to 55%).

7. Among the n feedstocks, 2. The production method according to claim 1, wherein the first feedstock is a hydrogenated product of catalytic cracking slurry oil, the nth feedstock is a coke distillate, and any other feedstock is a cracked product of a hydrogenated product of catalytic cracking slurry oil.

8. wherein n is 3; the number of the feedstocks is three, corresponding to a first feedstock, a second feedstock, and a third feedstock; the reaction period T of the coking reaction is divided into three reaction zones, corresponding to a first reaction zone, a second reaction zone, and a third reaction zone; 2. The production method according to claim 1, wherein the first feedstock oil is supplied to the coking reaction in the first reaction zone, the second feedstock oil is supplied to the coking reaction in the second reaction zone, and the third feedstock oil is supplied to the coking reaction in the third reaction zone.

9. The first method for producing a stock oil comprises:

9. The production method according to claim 8, comprising the steps of: feeding a refined slurry oil obtained by refining a catalytic cracking slurry oil to a hydrotreating system; carrying out a hydrogenation reaction in the presence of hydrogen gas and a hydrogenation catalyst; separating the obtained hydrogenated product to obtain a gas phase stream and a liquid phase stream; and feeding the liquid phase stream to a first separation system to obtain a first light oil and a first heavy oil to be used as the first feedstock oil.

10. The method of claim 9, wherein the catalytic cracking slurry oil has an ash content greater than 0.01 wt% and a sulfur content greater than 0.5 wt%.

11. 10. The method of claim 9, wherein the refined slurry oil has an ash content not exceeding 0.008 wt%, preferably an ash content not exceeding 0.005 wt%.

12. The method according to claim 9, wherein the purification treatment is a solid matter removal treatment, and the solid matter removal treatment is carried out by one or more of filtration, centrifugal sedimentation, and flocculation sedimentation, and is preferably carried out by filtration.

13. The conditions for carrying out the hydrogenation reaction are: 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; The liquid hourly space velocity per volume is 0.1 h －１ ~2.0h －１ , preferably 0.6 h －１ ~1.2 hours －１ The method according to claim 9, wherein

14. the liquid phase stream is a liquid phase stream from which non-condensable gases have been separated, preferably from which non-condensable gases and a naphtha fraction have been separated, and / or 10. The process of claim 9, wherein the sulfur content in the liquid phase stream does not exceed 0.4 wt%, preferably does not exceed 0.35 wt%.

15. The method according to claim 9, wherein the 5% distillation temperature of the first heavy oil is 330°C to 420°C, preferably 360°C to 400°C, and / or the 95% distillation temperature of the first light oil is 310°C to 420°C, preferably 340°C to 400°C.

16. The production method according to claim 9, wherein the first light oil is discharged from the unit or sent to a condensation reaction system for processing, or a portion of the first light oil is discharged from the unit and another portion is sent to a condensation reaction system for processing.

17. The conditions for carrying out the condensation reaction are as follows: The reaction temperature is 350°C to 530°C, preferably 380°C to 450°C; the reaction pressure is 0.01 MPa to 5 MPa, preferably 1 MPa to 3 MPa; The process according to claim 16, wherein the residence time is between 0.1 h and 15 h, preferably between 0.5 h and 6 h.

18. The method according to claim 8, wherein the reaction time of the first reaction zone occupies 5% to 40%, preferably 10% to 25%, of the reaction period T, and / or the reaction time of the second reaction zone occupies 15% to 85%, preferably 25% to 70% of the reaction period T.

19. The method according to claim 1, wherein the reaction period of the coking reaction is from 24 hours to 92 hours (preferably from 36 hours to 60 hours).

20. The method for producing the second feedstock oil comprises:

9. The method according to claim 8, further comprising the steps of: feeding the first feedstock (e.g., the first heavy oil) to a cracking reaction system, carrying out a cracking reaction in the presence of a carrier gas; feeding the resulting cracked product to a second separation system; and obtaining a second light oil, a middle distillate oil used as the second feedstock, and a second heavy oil by separation.

21. The decomposition reaction is carried out under the following conditions: The reaction temperature is 380°C to 520°C, preferably 420°C to 490°C; the reaction pressure is 0.1 MPa to 5 MPa, preferably 0.2 MPa to 1.0 MPa; The residence time is 0.01 h to 30 h, preferably 0.1 h to 3 h; 21. The process according to claim 20, wherein the mass ratio of oil to steam is from 100:0.1 to 100:20, preferably from 100:1 to 100:

8.

22. 21. The method of claim 20, The middle distillate oil has a 5% distillation temperature of 340°C to 430°C, preferably 360°C to 400°C, a 95% distillation temperature of 470°C to 530°C, preferably 485°C to 510°C, a sulfur content of not more than 0.43 wt%, preferably not more than 0.37 wt%, and an ash content of not more than 0.006 wt%, preferably not more than 0.004 wt%. and / or The 95% distillation temperature of the second light oil is 330°C to 430°C, preferably 350°C to 400°C; and / or The method according to claim 20, wherein the second heavy oil has a 5% distillation temperature of 470°C to 540°C, preferably 485°C to 520°C.

23. the first feedstock is fed to the cracking reaction system together with a first auxiliary feedstock; The first co-feedstock is The ash content is 0.02 wt% or less, preferably 0.01 wt% or less, The sulfur content is 0.4 wt% or less, preferably 0.35 wt% or less, The content of aromatic hydrocarbons having three or more rings is 40 wt % or more, the aromatic carbon fraction is 40 mol% or more, preferably 55 mol% to 80 mol%, The process according to claim 20, wherein the distillation range is from 300°C to 550°C, preferably from 330°C to 510°C.

24. 24. The process of claim 23, wherein the first auxiliary feedstock is one or more of catalytic cracking slurry oil, ethylene tar, vacuum gas oil, coker gas oil, deasphalted oil, and hydrogenation product oil.

25. 24. The process according to claim 23, wherein the mass ratio of the first auxiliary feedstock to the first feedstock is from 0:100 to 50:100, preferably from 5:100 to 20:

100.

26. the cracked product is sent to the second separation system along with a second auxiliary feed; The second co-feedstock is The ash content is 0.02 wt% or less, preferably 0.01 wt% or less, The sulfur content is 0.4 wt% or less, preferably 0.35 wt% or less, the aromatic hydrocarbon content is 50 wt % to 95 wt %, preferably 65 wt % to 90 wt %, of which the content of aromatic hydrocarbons having three or more rings is 40 wt % or more; The method according to claim 20, wherein the aromatic carbon fraction is 50 mol% or more, preferably 75 mol% or more.

27. 27. The process of claim 26, wherein the second auxiliary feedstock is one or more of catalytic cracking slurry oil, ethylene tar, vacuum gas oil, coker gas oil, and deasphalted oil.

28. 27. The process according to claim 26, wherein the mass ratio of the second co-feedstock to the cracked product is from 0:100 to 100:10, preferably from 5:100 to 20:

100.

29. The method according to claim 20, wherein the cracked product is sent to the second separation system together with the condensation reaction product of the first light oil and separated therein.

30. The method according to claim 29, wherein the mass ratio of the cracked product to the condensation reaction product of the first light oil is 100:0 to 100:20, preferably 100:0 to 100:

5.

31. The third method for producing a raw material oil comprises:

9. The production method according to claim 8, further comprising a step of sending the coker oil gas produced by the coking reaction to a third separation system and obtaining, by separation, a coker gas, a third light oil, and a third heavy oil used as the third feedstock oil.

32. The third heavy oil has a 5% distillation temperature of 280°C to 380°C, preferably 310°C to 360°C, and / or the third light oil has a 95% distillation temperature of 270°C to 380°C, preferably 300°C to 360°C. The production method according to claim 31.

33. The conditions for carrying out the coking reaction are: The temperature at the outlet of the heating furnace is 420°C to 560°C, preferably 440°C to 530°C, The temperature rise rate is 0.5°C / h to 30°C / h, preferably 3°C / h to 7°C / h; The pressure at the top of the coking tower is 0.01 MPa to 2.5 MPa, preferably 0.2 MPa to 1.3 MPa; The coking reaction is carried out under constant pressure or variable pressure, and when carried out under variable pressure, the pressure change rate is 0.1 MPa / h to 5 MPa / h; The method according to claim 1, wherein the reaction period is 24 hours to 92 hours (preferably 36 hours to 60 hours).

34. a feedstock supply unit configured to supply n feedstocks (n is an integer of 2 or more, preferably 2 to 15 or 3 to 5), wherein, where A (mol%) is the aromatic carbon fraction of the i-th (n-1≧i≧1) feedstock, B (mol%) is the aromatic carbon fraction of the (i+1)th feedstock, A1 (mol%) is the aromatic carbon fraction of the 1st feedstock, and B1 (mol%) is the aromatic carbon fraction of the nth feedstock, B≧A (preferably B−A≧5 mol% or B−A≧10 mol%) and B1 is greater than A1 (preferably B1−A1≧10 mol% or B1−A1≧20 mol%); a coking unit configured to receive the n feedstocks and perform a coking reaction thereon to obtain needle coke; a control unit configured to sequentially send the n feedstocks from the feedstock supply unit to the coking unit at predetermined time intervals.

35. wherein n is 3; a refining system used to receive and refine the catalytic cracking slurry oil to obtain a refined slurry oil; a hydrotreating system used to receive hydrogen gas and the refined slurry oil from the refining system, to carry out a hydrogenation reaction in the presence of a hydrogenation catalyst, and to separate the resulting hydrogenated product to obtain a gas phase stream and a liquid phase stream; a first separation system adapted to receive the liquid phase stream from the hydrotreating system and separate it to obtain a first light oil and a first heavy oil; a cracking reaction system that receives the first heavy oil from the first separation system and, optionally, a first auxiliary feedstock, and is used to carry out a cracking reaction in the presence of a carrier gas; a second separation system for receiving the reaction effluent from the cracking reaction system and, optionally, a second auxiliary feedstock, and for separating the reaction effluent into a second light oil, a middle distillate oil, and a second heavy oil; a coking unit used to receive the first heavy oil (i.e., first feedstock) from the first separation system, the middle distillate oil (i.e., second feedstock) from the second separation system, and the third heavy oil (i.e., third feedstock) from the third separation system, and to perform a coking reaction to obtain coker oil gas and needle coke; a third separation system for receiving the coker oil gas obtained from the coking unit and then separating the coker gas, a third light oil, and a third heavy oil; 35. The manufacturing apparatus of claim 34, comprising:

36. a condensation reaction system adapted to receive the first light oil from the first separation system; The first light oil is sent to a condensation reaction system and undergoes a condensation reaction in the presence of a condensation catalyst, The production apparatus according to claim 35, wherein the reaction effluent obtained by the condensation reaction is then sent to a second separation unit and subjected to separation together with the reaction effluent from the decomposition reaction system.

Images