A catalytic cracking diesel processing technology and processing system

Abstract

The present invention discloses a catalytic cracking diesel processing technology and processing system, comprising the following steps: (1) catalytic cracking diesel is cut to obtain a light fraction, a middle fraction and a heavy fraction; (2) the middle fraction enters a fluidized bed hydrogenation reaction unit for reaction, and obtains a gas phase material and a liquid phase material after separation; (3) the heavy fraction is contacted with an extractant, and an extract phase and a raffinate phase are obtained after extraction; (4) the extract phase is recovered by the extractant to obtain a regenerated extractant and a material rich in aromatics; (5) the material rich in aromatics enters a resin synthesis unit for cross-linking reaction, and the obtained reaction product is washed and separated to obtain a resin material and an oil phase material; (6) the light fraction and the liquid phase material enter a fixed bed hydrogenation reaction unit for reaction, and the reaction effluent is separated to obtain naphtha and unconverted diesel. A system for implementing the above process is also provided. In the process of the present invention, the catalytic diesel is pre-separated according to the property differences of different fractions, and then the processing route is selected according to the property characteristics of the catalytic diesel in different fractions.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a high-efficiency conversion process and system for catalytic cracking diesel. Background Art

[0002] Catalytic cracking technology is one of the most important technical means to lighten heavy oil. At present, the scale of catalytic cracking in China is nearly 240 million tons / year, and the output of catalytic cracking diesel (LCO) is nearly 55 million tons / year. Refining companies face many problems in handling LCO. Due to the high content of polycyclic aromatic hydrocarbons (usually greater than 70%), low cetane number, and high content of sulfur and nitrogen impurities in LCO, it is difficult to produce clean diesel blending components by hydrofining it, and the hydrogen consumption is very high. In addition, diesel consumption has reached saturation, and the economic efficiency of this route is low.

[0003] At present, the main methods for processing LCO in refineries include using it as a fuel oil blending component or using hydrogenation conversion technology to generate light aromatic components, but there are some technical problems. When used as a fuel oil blending component, the economic benefits are low, and the large amount of sulfur and nitrogen impurities in LCO will pollute the environment during combustion. From the current and future development perspective, LCO hydrogenation conversion to produce light aromatics is a relatively economical and efficient route. The core of this technology is to hydrogenate and saturate the cracking of other aromatic rings while retaining one aromatic ring in the polycyclic aromatics in LCO, and to control the saturation depth and ring opening depth through effective means to maximize the generation of single-ring aromatics at a lower hydrogen consumption. The current industrialized LCO hydrogenation conversion technologies for producing aromatics mainly include UOP's LCO-XTM technology, Sinopec's RLG and FD2A technologies, etc. Such technologies generally have problems such as low single-pass conversion rate, high energy consumption of the device and low yield of light aromatics. The main reasons are that the hydrogenation reaction network of polycyclic aromatics in LCO is complex, and the step-by-step hydrogenation ring-opening process is poorly controllable in the fixed bed. At the same time, the hydrogenation cracking process of three-ring and above polycyclic aromatics into single-ring aromatics has high hydrogen consumption and low economic efficiency.

[0004] CN107286987A provides a combined process for treating inferior diesel. The inferior diesel raw material is mixed with hydrogen and then enters the fixed bed hydrogenation reaction zone, and the hydrogenation reaction is carried out under the action of a hydrorefining catalyst; the resulting reaction oil is mixed with hydrogen and then enters the ebullated bed hydrocracking reaction zone, and the hydrocracking reaction is carried out in the presence of an ebullated bed hydroconversion catalyst, and the product is obtained after separation. The products of this technology are mainly gasoline and diesel. At the same time, the direct processing of catalytic diesel into a fixed bed has the problems of low light aromatics yield and high hydrogen consumption. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a high-efficiency separation and precise processing technology for catalytic diesel based on the concept of molecular refining. The processing technology separates polycyclic aromatic hydrocarbons in catalytic diesel as high-end resin raw materials, and the catalytic diesel rich in dicyclic aromatic hydrocarbons is directionally and efficiently converted into monocyclic aromatic hydrocarbons using a boiling bed hydrogenation technology in a fully back-mixed isothermal system. The process of the present invention can achieve the optimal path conversion and utilization of different hydrocarbon molecules in catalytic diesel, greatly promoting the improvement of quality and efficiency of refineries.

[0006] In order to achieve the above-mentioned object of the invention, the first aspect of the present invention provides a catalytic cracking diesel processing process, comprising the following steps:

[0007] (1) Catalytic cracking diesel is cut into light fraction, middle fraction and heavy fraction;

[0008] (2) the middle fraction obtained in step (1) enters an ebullated bed hydrogenation reaction unit, reacts in the presence of hydrogen and an ebullated bed hydrogenation catalyst, and obtains an ebullated bed reaction effluent;

[0009] (3) the heavy fraction obtained in step (1) is contacted with an extractant, and after extraction is completed, an extract phase and a raffinate phase are obtained;

[0010] (4) The extract phase obtained in step (3) enters an extractant recovery unit, and after the extractant is recovered, a regenerated extractant and an aromatics-rich material are obtained;

[0011] (5) The aromatics-rich material obtained in step (4) enters a resin synthesis unit, undergoes a cross-linking reaction under the action of a resin synthesis catalyst and a cross-linking agent, and the reaction product is washed and separated to obtain a resin material and an oil phase material;

[0012] (6) The light fraction obtained in step (1) and the ebullated bed reaction effluent obtained in step (2) enter a fixed bed hydrogenation reaction unit, react under the action of hydrogen and a supplementary hydrotreating catalyst, and the reaction effluent is separated to obtain naphtha and unconverted diesel.

[0013] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, catalytic cracking diesel generally refers to the diesel fraction produced from the catalytic cracking unit. Generally, the distillation range of catalytic cracking diesel is 150°C to 380°C, the aromatic content is 50wt% to 85wt%, and the nitrogen content is 500 to 1500mg / kg.

[0014] Furthermore, in the above-mentioned catalytic cracking diesel processing process, the catalytic cracking diesel in step (1) is cut to obtain a light fraction, a middle fraction and a heavy fraction; wherein the cutting point temperature of the light fraction and the middle fraction is 170-220°C, preferably 180-210°C; the cutting point temperature of the middle fraction and the heavy fraction is 270-330°C, preferably 280-320°C. wherein the light fraction is rich in monocyclic aromatic hydrocarbons, wherein the content of monocyclic aromatic hydrocarbons is 35wt%-60wt%; the middle fraction is rich in dicyclic aromatic hydrocarbons, wherein the content of dicyclic aromatic hydrocarbons is 50wt%-80wt%; the heavy fraction is rich in tricyclic aromatic hydrocarbons, wherein the content of tricyclic aromatic hydrocarbons is 40wt%-70wt%; in addition, wherein the nitrogen content of the light fraction is 50-250mg / kg, the nitrogen content of the middle fraction is 150-400mg / kg, and the nitrogen content of the heavy fraction is 400-4000mg / kg.

[0015] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the ebullated bed hydrogenation reaction unit can be provided with more than one ebullated bed reactor, and the ebullated bed reactor is preferably an ebullated bed reactor with a three-phase separator arranged inside the reactor. Specifically, the ebullated bed reactor with a three-phase separator developed by Fushun Petrochemical Research Institute of Sinopec can be adopted, such as the structure disclosed in ZL200810228414.4.

[0016] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the ebullated bed hydrogenation catalyst can be selected from the existing diesel hydrogenation catalyst in the art, or prepared by itself according to the method disclosed in the prior art. Specifically in the present invention, the preferred ebullated bed hydrogenation catalyst uses high-silicon alumina and molecular sieve as carriers, and uses Group VIII metals and Group VIB metals as active metal components. Based on the weight of the catalyst, the content of high-silicon alumina is 30% to 70%, the content of molecular sieve is 10% to 50%, the content of Group VIII metal in terms of oxide is 1% to 9%, and the content of Group VIB metal in terms of oxide is 10% to 30%. The Group VIII metal is preferably Ni and / or Co; the Group VIB metal is preferably W and / or Mo; the molecular sieve is selected from one or more of Y-type molecular sieve, β molecular sieve, ZSM-5 molecular sieve, SAPO molecular sieve, and MCM-41 mesoporous molecular sieve. The specific surface area of ​​the catalyst is 250 to 450 m 2 / g, and the pore volume is 0.30~0.50mL / g.

[0017] Furthermore, in the above-mentioned catalytic cracking diesel processing process, the process conditions of the ebullated bed hydrogenation reaction unit are: reaction temperature is 350-450°C, preferably 380-440°C, reaction pressure is 5.0-15.0MPa, preferably 6.0-12.0MPa, hydrogen-to-oil volume ratio is 500-2000, preferably 600-1500, liquid hourly volume space velocity is 0.1-5.0h -1 , preferably 0.2~2.0h -1 .

[0018] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the extractant can be selected from at least one of sulfone compounds, aldehyde compounds, alkanone compounds, amide compounds, and ionic liquids, preferably alkanone compounds; specifically, the extractant can be at least one of cyclopentane sulfone, N-methylpyrrolidone, pyrrolidone, N,N-dimethylacetamide, caprolactam, [emim]N(CN)2, and [3-mebupy]N(CN)2.

[0019] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the extraction process can be achieved by using an aromatic extraction device, and the operating conditions of the extraction are: temperature of 30-200°C, preferably 30-100°C, and a weight ratio of the extractant to the heavy fraction of 0.5-10.0, preferably 1.0-5.0.

[0020] Furthermore, in the above catalytic cracking diesel processing technology, the extractant recovery unit includes a distillation device, and the extract phase enters the extractant recovery unit and the extractant is recovered to obtain a regenerated extractant and a material rich in aromatics.

[0021] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the operating conditions of the extractant recovery unit are generally to adjust the distillation cut point according to the boiling point of the extractant.

[0022] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the cross-linking agent can be selected from at least one of alcohol compounds, aldehyde compounds, acyl compounds, olefin compounds, organic acid compounds and their derivatives, preferably aldehyde compounds; the specific cross-linking agent can be at least one of formaldehyde, benzaldehyde, terephthalaldehyde, p-tolualdehyde, trioxymethylene and polyformaldehyde.

[0023] Furthermore, in the above catalytic cracking diesel processing technology, the resin synthesis catalyst can be selected from at least one of concentrated sulfuric acid, oleum, chlorosulfuric acid, sulfur trioxide, aminosulfuric acid, and p-toluenesulfonic acid.

[0024] Furthermore, in the above catalytic cracking diesel processing technology, the resin synthesis unit can use parallel batch reactors to achieve continuous production.

[0025] Furthermore, in the above catalytic cracking diesel processing technology, the reaction conditions of the resin synthesis unit are as follows: the reaction temperature is 50 to 200°C, preferably 80 to 160°C; the reaction time is 0.5 to 8.0 hours. -1 , preferably 1.0~5.0h -1 ,; The molar ratio of the heavy fraction and the cross-linking agent is 0.25-5.0, preferably 0.5-2.0; The amount of the resin synthesis catalyst is 5%-80% of the total weight of the materials in the reaction system (including the heavy fraction, the cross-linking agent and the synthesis catalyst), preferably 10-50%.

[0026] Furthermore, in the above catalytic cracking diesel processing technology, the specific process of resin synthesis in step (5) is: the cross-linking agent and the catalyst are introduced into the reactor, mixed evenly, and then the heavy fraction is added to react. After the reaction is completed, the resin material and the oil phase material are obtained by washing and separation.

[0027] Furthermore, in the above catalytic cracking diesel processing process, the washing in step (5) is washing with water until the reaction liquid becomes neutral.

[0028] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the separation in step (5) is to cut the generated oil after reaction and washing into fractions, and the cutting temperature point is preferably 280°C to 350°C. After cutting, resin material and oil phase material are obtained. The resin material can be further processed to obtain a new type of thermosetting polymer material with better performance.

[0029] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, part or all of the oil phase material separated in step (5) can be introduced into an ebullated bed hydrogenation reaction unit to be mixed with the middle fraction for treatment.

[0030] Furthermore, in the above-mentioned catalytic cracking diesel processing process, the operating conditions of the fixed bed hydrogenation reaction unit in step (6) are: reaction temperature is 200-400°C, preferably 200-300°C, reaction pressure is 2.0-10.0 MPa, preferably 2.0-5.0 MPa, liquid hourly volume space velocity is 0.1-5.0 h -1 , preferably 1.0~3.0h -1 , the volume ratio of hydrogen to oil is 300-1500, preferably 400-1000.

[0031] Furthermore, in the above-mentioned catalytic cracking diesel processing process, the fixed bed hydrogenation reaction unit can be provided with at least one fixed bed hydrogenation reactor, preferably 1 or 2 fixed bed hydrogenation reactors; one or more catalyst beds can be provided in the fixed bed hydrogenation reactor. Furthermore, in the above-mentioned technical scheme, the supplementary hydrogenation refining catalyst can use commercially available products, or it can be prepared according to conventional knowledge in the field. The supplementary hydrogenation refining catalyst uses alumina or silicon-containing alumina as a carrier, and the active components are selected from the VIB group metals of Mo and / or W and / or the VIII group metals of Co and / or Ni. Based on the weight of the catalyst, the content of the VIB group metal and the VIII group metal content are 8wt% to 25wt% and 2wt% to 18wt% respectively in terms of oxide.

[0032] Furthermore, in the above-mentioned catalytic cracking diesel processing process, the naphtha obtained after separation of the reaction effluent in step (6) can be further divided into light naphtha and heavy naphtha as needed. Generally, the final distillation point of the light naphtha is controlled to be no higher than 65°C, and the light naphtha can be used as a raw material for the steam cracking unit to produce ethylene. The distillation range of the heavy naphtha fraction is generally controlled to be 65°C to 210°C, and the heavy naphtha can be used as a raw material for the reforming unit to produce olefins.

[0033] Furthermore, in the above-mentioned catalytic cracking diesel processing technology, the raffinate phase can enter the fixed bed hydrogenation reaction unit and be mixed with the light fraction and the ebullating bed reaction effluent obtained in step (2) for treatment.

[0034] Furthermore, in the above-mentioned catalytic cracking diesel processing process, part or all of the unconverted diesel separated in step (6) is recycled to the ebullated bed hydrogenation reaction unit and mixed with the middle fraction for processing.

[0035] A second aspect of the present invention provides a catalytic cracking diesel processing system, the system comprising

[0036] A first fractionation unit, which is used to receive catalytic cracking diesel and obtain light fraction, middle fraction and heavy fraction after cutting;

[0037] An ebullated bed hydrogenation reaction unit, which is used to receive the middle fraction from the first fractionation unit, and react in the presence of hydrogen and an ebullated bed hydrogenation catalyst to obtain an ebullated bed reaction effluent;

[0038] An extraction unit, which is used to receive the extractant and the heavy fraction from the first fractionation unit, and obtain an extract phase and a raffinate phase after the extraction is completed;

[0039] An extractant recovery unit, which is used to receive the extract phase from the extraction unit and obtain a regenerated extractant and an aromatics-rich material after recovering the extractant;

[0040] The resin synthesis unit is used to receive the aromatics-rich material from the extractant recovery unit, and to carry out a cross-linking reaction under the action of a resin synthesis catalyst and a cross-linking agent, and to obtain a resin material and an oil phase material after washing and separation of the reaction product;

[0041] A fixed bed hydrogenation reaction unit, which is used to receive the light fraction of the first fractionation unit and the ebullated bed reaction effluent from the ebullated bed hydrogenation reaction unit, and react under the action of hydrogen and a supplementary hydrorefining catalyst;

[0042] A gas-liquid separation unit, which is used to receive the reaction effluent from the fixed bed hydrogenation reaction unit and obtain gas phase material and liquid phase material after separation;

[0043] The second fractionation unit is used to receive the liquid phase material from the gas-liquid separation unit and obtain naphtha and unconverted diesel after fractionation.

[0044] Furthermore, in the above catalytic cracking diesel processing system, the first fractionation unit is provided with one or more devices with fractionation function, specifically a fractionation tower, which can be any one of the existing fractionation towers in the art, specifically a plate tower or a packed tower.

[0045] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the ebullated bed hydrogenation reaction unit can be provided with more than one ebullated bed reactor, and the ebullated bed reactor is preferably an ebullated bed reactor with a three-phase separator arranged inside the reactor. Specifically, the ebullated bed reactor with a three-phase separator developed by Fushun Petrochemical Research Institute of Sinopec can be adopted, such as the structure disclosed in ZL200810228414.4.

[0046] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the fixed bed hydrogenation reaction unit may be provided with more than one fixed bed hydrogenation reactor, preferably 1 or 2 fixed bed hydrogenation reactors.

[0047] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the extraction unit can be implemented by an aromatics extraction device.

[0048] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the extractant recovery unit includes a distillation device, and the extract phase enters the extractant recovery unit and the extractant is recovered to obtain a regenerated extractant and a material rich in aromatics.

[0049] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the system also includes a hydrogen recovery unit, including light hydrocarbon recovery equipment, a hydrogen sulfide removal tower and a membrane separation equipment, which is used to receive the gas phase material from the gas-liquid separation unit, and obtain light hydrocarbons and circulating hydrogen after processing. Furthermore, the circulating hydrogen can be introduced into the boiling bed hydrogenation reaction unit through a pipeline for use.

[0050] Furthermore, in the above catalytic cracking diesel processing system, the unconverted oil obtained from the second fractionation unit is introduced into the ebullating bed hydrogenation reaction unit through a pipeline for treatment.

[0051] Furthermore, in the above catalytic cracking diesel processing system, the raffinate phase obtained from the extraction unit is introduced into the fixed bed hydrogenation reaction unit through a pipeline for treatment.

[0052] Furthermore, in the above catalytic cracking diesel processing system, the oil phase material obtained by the resin synthesis unit is introduced into the ebullating bed hydrogenation reaction unit through a pipeline for treatment.

[0053] Furthermore, in the above catalytic cracking diesel processing system, the second fractionation unit is provided with one or more devices with fractionation function, specifically a fractionation tower can be used, and the fractionation tower can be any one of the existing fractionation towers in the art, specifically a plate tower or a packed tower.

[0054] Furthermore, in the above catalytic cracking diesel processing system, the naphtha obtained after separation in the second fractionation unit can be further divided into light naphtha and heavy naphtha as needed.

[0055] Furthermore, in the above-mentioned catalytic cracking diesel processing system, the gas-liquid separation unit can adopt at least one of the existing gas-liquid separators in the art. Generally, the gas-liquid separation unit includes a hot high-pressure separator, a hot low-pressure separator, a cold high-pressure separator, and a cold low-pressure separator.

[0056] Compared with the prior art, the catalytic cracking diesel processing technology and processing system provided by the present invention have the following advantages:

[0057] 1. In the catalytic diesel processing technology of the present invention, the catalytic diesel is pre-separated according to the property differences of different fractions, and then the processing route is selected according to the property characteristics of the catalytic diesel in different fractions.

[0058] 2. In the catalytic diesel processing technology of the present invention, the nitrogen of the catalytic diesel is mainly enriched in polycyclic aromatic hydrocarbons, and the nitrogen content in the dicyclic aromatic hydrocarbon-rich fraction is greatly reduced compared with that of the catalytic diesel, and can directly enter the ebullated bed hydrogenation unit without hydrogenation refining; at the same time, in the ebullated bed hydrogenation unit, in order to achieve a high conversion rate and high selectivity of dicyclic aromatic hydrocarbons to light aromatic hydrocarbons, a higher reaction temperature is required. Since there are few polycyclic aromatic hydrocarbons that are prone to coking in the dicyclic aromatic hydrocarbon-rich fraction, the coking of the device can be greatly reduced.

[0059] 3. In the catalytic diesel processing technology of the present invention, the polycyclic aromatic hydrocarbons-rich fraction contains a considerable amount of saturated hydrocarbons, which can be extracted by solvent extraction, which can further improve the enrichment of polycyclic aromatic hydrocarbons and the subsequent resin yield; at the same time, the extracted large molecular saturated hydrocarbons are high-quality raw materials suitable for cracking and preparing ethylene.

[0060] 4. In the catalytic cracking diesel processing technology provided by the present invention, compared with polycyclic aromatic hydrocarbons without impurities, polycyclic aromatic hydrocarbons containing nitrogen heteroatoms have a faster synthetic resin efficiency due to the electron-sharing effect of nitrogen groups. Therefore, the synthetic resin of polycyclic aromatic hydrocarbons without impurities is relatively slow. By controlling the reaction time, while obtaining aromatic resins, polycyclic aromatic hydrocarbon fractions with low impurity content are also obtained, reducing the return to the ebullated bed hydrogenation unit, and further improving the yield and quality of the target product naphtha.

[0061] 5. In the catalytic diesel processing technology described in the present invention, the ebullating bed hydrogenation technology is used to convert dicyclic aromatics, which cleverly combines the characteristics of the ebullating bed suitable for high exothermic systems and the conversion rules of dicyclic aromatics to monocyclic aromatics, thereby achieving precise and directional conversion of aromatics. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of the catalytic cracking diesel processing technology and processing system of the present invention.

[0063] The main drawings are explained as follows: 1 is catalytic cracking diesel, 2 is the first fractionation unit, 3 is the light fraction, 4 is the middle fraction, 5 is the ebullated bed hydrogenation reaction unit, 6 is the ebullated bed reaction effluent, 7 is the fixed bed hydrogenation reaction unit, 8 is the gas-liquid separation unit, 9 is the gas phase material, 10 is the hydrogen recovery unit, 11 is the circulating hydrogen, 12 is the light hydrocarbon component, 13 is the liquid phase material, 14 is the second fractionation unit, 15 is the light naphtha, 16 is the heavy naphtha, 17 is the unconverted diesel, 18 is the heavy fraction, 19 is the extraction unit, 20 is the raffinate phase, 21 is the extraction phase, 22 is the extractant recovery unit, 23 is the regenerated extractant, 24 is the aromatics-rich material, 25 is the resin synthesis unit, 26 is the oil phase material, and 27 is the resin material.

[0064] Figure 2 This is a schematic diagram of the process flow adopted in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0065] The technical scheme and technical effects of the present invention are further described below in conjunction with the accompanying drawings and specific implementation methods.

[0066] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0067] In this document, for the convenience of description, spatial relative terms such as "below", "below", "down", "above", "above", "upper", etc. may be used to describe the relationship between one element or feature and another element or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different directions of objects in use or operation in addition to the directions drawn in the drawings. For example, if the object in the figure is turned over, the elements described as being "below" or "below" other elements or features will be oriented "above" the elements or features. Therefore, the exemplary term "below" can include both below and above directions. Objects may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0068] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0069]

[0043] All numerical values ​​for parameters (eg, amounts or conditions) herein are to be understood as being modified in all instances by the term "about", whether or not "about" actually appears before the numerical value.

[0070] like Figure 1 As shown, the catalytic cracking diesel processing process provided by the present invention is as follows: catalytic cracking diesel 1 enters the first fractionation unit 2, and after separation, a light fraction 3, a middle fraction 4 and a heavy fraction 18 are obtained; the middle fraction 4 and hydrogen are mixed and enter the ebullated bed hydrogenation reaction unit 5; the ebullated bed reaction effluent 6 obtained after the reaction and the light fraction 3 are mixed and enter the fixed bed hydrogenation reaction unit 7; the fixed bed hydrogenation generated oil obtained after the reaction enters the gas-liquid separation unit 8 for separation to obtain a gas phase material 9 and a liquid phase material 13; the gas phase material 9 enters the hydrogen recovery unit 10 for treatment to obtain circulating hydrogen 11 and a light hydrocarbon fraction 12; the liquid phase material 13 enters the second fractionation unit 14 for separation to obtain a light naphtha 15, a heavy naphtha 16 and an unconverted oil diesel 17, wherein the unconverted diesel 17 is returned to the ebullated bed hydrogenation reaction unit 5 for further processing. The heavy fraction 18 enters the extraction unit 19, and after reacting with the extractant, a raffinate phase 20 and an extract phase 21 are obtained, wherein the raffinate phase 20 can be selected to enter the fixed bed hydrogenation reaction unit 7 for processing, or can be selected to be discharged as a product; the extract phase 21 (a mixed flow of the extractant and the extract) enters the extractant recovery unit 22, and after separation, a regenerated extractant 23 and an aromatics-rich material 24 are obtained, and the regenerated extractant 23 is returned to the extraction unit 19 for recycling; the aromatics-rich material 24 enters the resin synthesis unit 25, and a cross-linking reaction is carried out under the action of a catalyst and a cross-linking agent. The reaction product obtained is washed and separated to obtain a resin material 27 and an oil phase material 26, and the oil phase material 26 can be returned to the ebullated bed hydrogenation reaction unit for processing.

[0071] The properties of the catalytic cracking diesel feedstock used in the examples and comparative examples of the present invention are shown in Table 1.

[0072] Table 1 Catalytic diesel properties

[0073] project data <![CDATA[Density (20 °C) / g×cm -3 > 0.9794 Distillation range / ℃ IBP / 10% 195.7 / 212.4 30% / 50% 242.5 / 261.4 70% / 90% 313.6 / 350.3 95% / EBP 365.3 / 372.1 S,wt 0.456 N,wt% 0.132 Mass Spectrum Composition, wt% Alkanes 14.3 Total cycloalkanes 14.7 Total aromatics 71.0 Example 1

[0074] use Figure 1 In the process flow shown in the figure, the cut point between light fraction and middle fraction is 210℃, and the cut point between middle fraction and heavy fraction is 320℃; the reaction conditions of the ebullated bed hydrogenation reaction unit are reaction temperature 415℃, reaction pressure 10.0MPa, hydrogen-oil volume ratio 800, liquid collection volume space velocity 0.8h -1 The catalyst used is the spherical FC-24B hydrocracking catalyst developed by Sinopec Dalian Petrochemical Research Institute. The extraction unit uses N-methylpyrrolidone as the extractant, the extraction temperature is 50°C, and the agent-oil weight ratio is 2.0; the resin synthesis unit uses concentrated sulfuric acid as the catalyst, and the cross-linking agent is benzaldehyde. The molar ratio of the heavy fraction, the cross-linking agent and the concentrated sulfuric acid is 1:1:0.5, the temperature is 100°C, and the reaction time is 2h. The fixed bed reaction unit has a reaction temperature of 280°C, a reaction pressure of 4.0MPa, and a volume space velocity of 1.5h -1 , the volume ratio of hydrogen to oil is 800. The fixed bed hydrogenation reaction unit uses the FGH-21 catalyst from Fushun Petrochemical Research Institute. The test results are shown in Table 2. Example 2

[0075] The process flow is basically the same as that of Example 1, except that the material 26 in the resin synthesis unit is not returned to the ebullated bed hydrogenation unit. The cut point between the light fraction and the middle fraction is 190°C, and the cut point between the middle fraction and the heavy fraction is 300°C; the reaction conditions of the ebullated bed hydrogenation reaction unit are reaction temperature 425°C, reaction pressure 8.0 MPa, hydrogen-to-oil volume ratio 1000, and liquid collection volume space velocity 0.6 h -1 The catalyst used is the spherical FC-24B hydrocracking catalyst developed by Sinopec Dalian Petrochemical Research Institute. The extraction unit uses pyrrolidone as the extractant, the extraction temperature is 80°C, and the agent-oil weight ratio is 4.0; the resin synthesis unit uses concentrated sulfuric acid as the catalyst, and the cross-linking agent is formaldehyde. The molar ratio of heavy fraction, cross-linking agent and concentrated sulfuric acid is 1:0.8:0.4, the temperature is 80°C, and the reaction time is 2h. The fixed bed reaction unit has a reaction temperature of 280°C, a reaction pressure of 3.0MPa, and a volume space velocity of 1.5h -1 , the volume ratio of hydrogen to oil is 800. The fixed bed hydrogenation reaction unit uses the FGH-21 catalyst from Fushun Petrochemical Research Institute. The test results are shown in Table 2. Example 3

[0076] The process flow is basically the same as that of Example 1, except that the cut point between the light fraction and the middle fraction is 210°C, and the cut point between the middle fraction and the heavy fraction is 320°C; the reaction conditions of the ebullated bed hydrogenation reaction unit are reaction temperature 405°C, reaction pressure 12.0 MPa, hydrogen-to-oil volume ratio 1000, and liquid collection volume space velocity 0.6 h -1 The catalyst used was FC-24B hydrocracking catalyst produced by Dalian Petrochemical Research Institute of Sinopec after spheroidization. The extraction unit used N-methylpyrrolidone as the extractant, the extraction temperature was 80°C, and the agent-oil weight ratio was 2.0; the resin synthesis unit used concentrated sulfuric acid as the catalyst, and the cross-linking agent was p-methylbenzaldehyde. The molar ratio of the heavy fraction, the cross-linking agent, and the concentrated sulfuric acid was 1:1:0.6. The temperature was 100°C and the reaction time was 3h. The fixed bed reaction unit had a reaction temperature of 300°C, a reaction pressure of 5.0MPa, and a volume space velocity of 2.0 h -1 , the volume ratio of hydrogen to oil is 600. The fixed bed hydrogenation reaction unit uses the FGH-21 catalyst from Fushun Petrochemical Research Institute. The test results are shown in Table 2.

[0077] Comparative Example 1

[0078] This comparative example adopts Figure 2 In the process flow shown, the catalytic diesel 1 and hydrogen are mixed and enter the first fixed bed reactor 2 for hydrofining reaction to remove sulfur and nitrogen impurities and saturate aromatics. The hydrogenated oil obtained after the reaction then enters the second fixed bed reactor 3, in which a hydrocracking reaction is carried out. The hydrogenated oil obtained enters the gas-liquid separator 4. The gas phase stream obtained after separation enters the hydrogen recovery unit 5 for treatment to obtain circulating hydrogen 7 and light hydrocarbon components 6. The liquid phase stream enters the fractionation system 8 for separation to obtain light naphtha 9, heavy naphtha 10 and unconverted diesel 11, wherein the unconverted diesel 11 is returned to the second fixed bed reactor for further reaction. Among them, the catalysts loaded in the first fixed bed reactor and the second fixed bed reactor are FF-36 brand hydrofining catalyst and FC-24B hydrocracking catalyst developed by Sinopec Dalian Petrochemical Research Institute, respectively. The conditions of the first fixed bed reactor are: reaction temperature of 370°C, reaction pressure of 8.0MPa, hydrogen-oil volume ratio of 700, reaction space velocity of 0.8h -1 ; Second fixed bed reactor conditions: reaction temperature 405°C, reaction pressure 8.0MPa, hydrogen to oil volume ratio 1200, reaction space velocity 0.8h -1 The specific test results are shown in Table 2.

[0079] Comparative Example 2

[0080] This comparative example adopts Figure 3In the process flow chart shown, the catalytic diesel 1 and hydrogen are mixed and enter the fixed bed reactor 2 for hydrofining reaction, sulfur and nitrogen impurities are removed, and aromatics are saturated. The hydrogenated oil obtained after the reaction then enters the ebullating bed reactor 3, in which the hydrocracking reaction is carried out, and the hydrogenated oil obtained enters the gas-liquid separator 4. The gas phase stream obtained after separation enters the hydrogen recovery unit 5 for treatment to obtain circulating hydrogen 7 and light hydrocarbon components 6. The liquid phase stream enters the fractionation system 8 for separation to obtain light naphtha 9, heavy naphtha 10 and unconverted diesel 11, wherein the unconverted diesel 11 is returned to the second fixed bed reactor for further reaction. Among them, the catalysts loaded in the fixed bed reactor are the FF-36 brand hydrofining catalyst developed by Sinopec Dalian Petrochemical Research Institute, and the ebullating bed reactor is loaded with the spherical FC-24B hydrocracking catalyst developed by Sinopec Dalian Petrochemical Research Institute. The fixed bed reactor conditions are: reaction temperature of 370°C, reaction pressure of 8.0MPa, hydrogen-to-oil volume ratio of 700, reaction space velocity of 0.8h -1 ; Ebullating bed reactor conditions: reaction temperature 415°C, reaction pressure 8.0MPa, hydrogen-oil volume ratio 1200, reaction space velocity 0.8h -1 The specific test results are shown in Table 2.

[0081] Table 2 Test results of examples and comparative examples

[0082] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Hydrogen consumption, wt% 2.5 2.4 2.7 3.7 3.8 Liquid yield (naphtha), wt% 80.5 67.0 78.5 89.0 88.0 Sulfur content in naphtha, ppm <1.0 <1.0 <1.0 <1.0 <1.0 Nitrogen content in naphtha, ppm <1.0 <1.0 <1.0 <1.0 <1.0 C6-C9 aromatics yield in naphtha, wt% 55.0 57.4 54.5 40.0 43.5 BTX yield, % 36.2 31.8 34.9 26.7 29.5 Resin yield, wt% 12.5 13.0 13.7 0 0 .

Claims

1. A catalytic cracking diesel processing process, comprising the following steps: (1) Catalytic cracking diesel is cut into light fraction, middle fraction and heavy fraction; in, The cutting point temperature between light fraction and middle fraction is 170~220℃, and the cutting point temperature between middle fraction and heavy fraction is 270~330℃; (2) the middle fraction obtained in step (1) enters an ebullated bed hydrogenation reaction unit, reacts in the presence of hydrogen and an ebullated bed hydrogenation catalyst, and obtains an ebullated bed reaction effluent; (3) the heavy fraction obtained in step (1) is contacted with an extractant, and after extraction is completed, an extract phase and a raffinate phase are obtained; (4) The extract phase obtained in step (3) enters an extractant recovery unit, and after the extractant is recovered, a regenerated extractant and an aromatics-rich material are obtained; (5) The aromatics-rich material obtained in step (4) enters a resin synthesis unit, undergoes a cross-linking reaction under the action of a resin synthesis catalyst and a cross-linking agent, and the reaction product is washed and separated to obtain a resin material and an oil phase material; (6) The light fraction obtained in step (1) and the ebullated bed reaction effluent obtained in step (2) enter a fixed bed hydrogenation reaction unit, react under the action of hydrogen and a supplementary hydrotreating catalyst, and the reaction effluent is separated to obtain naphtha and unconverted diesel.

2. The catalytic cracking diesel processing process according to claim 1, in, Catalytic cracking diesel refers to the diesel fraction produced from a catalytic cracking unit. The distillation range of catalytic cracking diesel is 150°C to 380°C, and the aromatic content is 50wt% to 85wt%.

3. The catalytic cracking diesel processing process according to claim 1, in, In step (1), the cutting point temperature between the light fraction and the middle fraction is 180-210°C; the cutting point temperature between the middle fraction and the heavy fraction is 280-320°C.

4. The catalytic cracking diesel processing process according to claim 1, in, In step (1), the light fraction is rich in monocyclic aromatic hydrocarbons, wherein the content of monocyclic aromatic hydrocarbons is 35 wt% to 60 wt%; the middle fraction is rich in dicyclic aromatic hydrocarbons, wherein the content of dicyclic aromatic hydrocarbons is 50 wt% to 80 wt%; and the heavy fraction is rich in tricyclic aromatic hydrocarbons, wherein the content of tricyclic aromatic hydrocarbons is 40 wt% to 70 wt%.

5. The catalytic cracking diesel processing process according to claim 1, in, The process conditions of the ebullating bed hydrogenation reaction unit are: reaction temperature of 350-450°C, reaction pressure of 5.0-15.0 MPa, hydrogen-oil volume ratio of 500-2000, liquid hourly volume space velocity of 0.1-5.0 h -1 .

6. The catalytic cracking diesel processing process according to claim 1, in, The process conditions of the ebullating bed hydrogenation reaction unit are: reaction temperature of 380-440°C, reaction pressure of 6.0-12.0 MPa, hydrogen-oil volume ratio of 600-1500, liquid hourly volume space velocity of 0.2-2.0 h -1 .

7. The catalytic cracking diesel processing process according to claim 1, in, The extractant is selected from at least one of sulfone compounds, aldehyde compounds, alkanone compounds, amide compounds and ionic liquids.

8. The catalytic cracking diesel processing process according to claim 1, in, The extractant is selected from alkanone compounds.

9. The catalytic cracking diesel processing process according to claim 1, in, The extractant is at least one of sulfolane, N-methylpyrrolidone, pyrrolidone, N,N-dimethylacetamide, caprolactam, [emim]N(CN)2, and [3-mebupy]N(CN)2.

10. The catalytic cracking diesel processing process according to claim 1, in, The operating conditions of the extraction process are: temperature of 30-200°C, and a weight ratio of the extractant to the heavy fraction of 0.5-10.

0.

11. The catalytic cracking diesel processing process according to claim 1, in, The operating conditions of the extraction process are: temperature of 30-100°C, and a weight ratio of the extractant to the heavy fraction of 1.0-5.

0.

12. The catalytic cracking diesel processing process according to claim 1, in, The cross-linking agent is selected from at least one of organic acid compounds and their derivatives, alcohol compounds, aldehyde compounds, acyl compounds, and olefin compounds.

13. The catalytic cracking diesel processing process according to claim 1, in, The crosslinking agent is selected from aldehyde compounds.

14. The catalytic cracking diesel processing process according to claim 1, in, The cross-linking agent is at least one of formaldehyde, benzaldehyde, terephthalaldehyde, p-tolualdehyde and paraformaldehyde.

15. The catalytic cracking diesel processing process according to claim 1, in, The crosslinking agent is trioxymethylene.

16. The catalytic cracking diesel processing process according to claim 1, in, The resin synthesis catalyst is selected from at least one of concentrated sulfuric acid, chlorosulfuric acid, sulfur trioxide, aminosulfuric acid and p-toluenesulfonic acid.

17. The catalytic cracking diesel processing process according to claim 1, in, The resin synthesis catalyst is selected from oleum.

18. The catalytic cracking diesel processing process according to claim 1, in, The reaction conditions of the resin synthesis unit are as follows: reaction temperature is 50-200°C, reaction time is 0.5-8.0h -1 The molar ratio of the heavy fraction to the cross-linking agent is 0.25 to 5.0, and the amount of the resin synthesis catalyst is 5% to 80% of the total weight of the materials in the reaction system.

19. The catalytic cracking diesel processing process according to claim 1, in, The reaction conditions of the resin synthesis unit are as follows: reaction temperature is 80-160°C, reaction time is 1.0-5.0h -1 The molar ratio of the heavy fraction to the cross-linking agent is 0.5 to 2.0, and the amount of the resin synthesis catalyst is 10% to 50% of the total weight of the materials in the reaction system.

20. The catalytic cracking diesel processing process according to claim 1, in, The separation in step (5) is to cut the generated oil after reaction and washing into fractions at a cutting temperature of 280°C to 350°C. After cutting, resin material and oil phase material are obtained. The resin material is further processed to obtain a new type of thermosetting polymer material.

21. The catalytic cracking diesel processing process according to claim 1, in, Part or all of the oil phase material separated in step (5) is introduced into an ebullated bed hydrogenation reaction unit and mixed with the middle fraction for treatment.

22. The catalytic cracking diesel processing process according to claim 1, in, The operating conditions of the fixed bed hydrogenation reaction unit in step (6) are: reaction temperature of 200-400°C, reaction pressure of 2.0-10.0 MPa, liquid hourly volume space velocity of 0.1-5.0 h -1 , the volume ratio of hydrogen to oil is 300-1500.

23. The catalytic cracking diesel processing process according to claim 1, in, The operating conditions of the fixed bed hydrogenation reaction unit in step (6) are: reaction temperature of 200-300°C, reaction pressure of 2.0-5.0 MPa, liquid hourly volume space velocity of 1.0-3.0 h -1 ; The volume ratio of hydrogen to oil is 400~1000.

24. The catalytic cracking diesel processing process according to claim 1, in, The raffinate phase enters the fixed bed hydrogenation reaction unit and is mixed with the light fraction and the liquid phase material obtained in step (2) for treatment.

25. The catalytic cracking diesel processing process according to claim 1, in, Part or all of the unconverted diesel separated in step (6) is recycled to the ebullated bed hydrogenation reaction unit and mixed with the middle fraction for processing.

26. A catalytic cracking diesel processing system for implementing the catalytic cracking diesel processing process described in any one of claims 1 to 25, wherein the catalytic cracking diesel processing system comprises A first fractionation unit, which is used to receive catalytic cracking diesel and obtain light fraction, middle fraction and heavy fraction after cutting; An ebullated bed hydrogenation reaction unit, which is used to receive the middle fraction from the first fractionation unit, and react in the presence of hydrogen and an ebullated bed hydrogenation catalyst to obtain an ebullated bed reaction effluent after the reaction; An extraction unit, which is used to receive the extractant and the heavy fraction from the first fractionation unit, and obtain an extract phase and a raffinate phase after the extraction is completed; An extractant recovery unit, which is used to receive the extract phase from the extraction unit and obtain a regenerated extractant and an aromatics-rich material after recovering the extractant; The resin synthesis unit is used to receive the aromatics-rich material from the extractant recovery unit, and to carry out a cross-linking reaction under the action of a resin synthesis catalyst and a cross-linking agent, and to obtain a resin material and an oil phase material after washing and separation of the reaction product; A fixed bed hydrogenation reaction unit, which is used to receive the light fraction of the first fractionation unit and the ebullated bed reaction effluent of the ebullated bed hydrogenation reaction unit, and react under the action of hydrogen and a supplementary hydrorefining catalyst; A gas-liquid separation unit, which is used to receive the reaction effluent from the fixed bed hydrogenation reaction unit and obtain gas phase material and liquid phase material after separation; The second fractionation unit is used to receive the liquid phase material from the gas-liquid separation unit and obtain naphtha and unconverted diesel after fractionation.

27. A catalytic cracking diesel processing system according to claim 26, in, The ebullated bed hydrogenation reaction unit is provided with more than one ebullated bed reactor, and the ebullated bed reactor adopts an ebullated bed reactor with a three-phase separator arranged inside the reactor.

28. A catalytic cracking diesel processing system according to claim 26, in, The fixed bed hydrogenation reaction unit is provided with more than one fixed bed hydrogenation reactor.

29. The catalytic cracking diesel processing system according to claim 26, in, The fixed bed hydrogenation reaction unit is equipped with 1 or 2 fixed bed hydrogenation reactors.

30. The catalytic cracking diesel processing system according to claim 26, in, The extraction unit is realized by using an aromatic extraction device.

31. A catalytic cracking diesel processing system according to claim 26, in, The extractant recovery unit comprises a distillation device. After the extract phase enters the extractant recovery unit, the extractant is recovered to obtain a regenerated extractant and a material rich in aromatics.

32. The catalytic cracking diesel processing system according to claim 26, in, The catalytic cracking diesel processing system also includes a hydrogen recovery unit, including light hydrocarbon recovery equipment, a hydrogen sulfide removal tower and a membrane separation device, which is used to receive gaseous materials from the gas-liquid separation unit, obtain light hydrocarbons and circulating hydrogen after processing, and the circulating hydrogen is introduced into the boiling bed hydrogenation reaction unit through a pipeline for use.

33. A catalytic cracking diesel processing system according to claim 26, in, The unconverted oil obtained from the second fractionation unit is introduced into the ebullated bed hydrogenation reaction unit through a pipeline for treatment.

34. A catalytic cracking diesel processing system according to claim 26, in, The raffinate phase obtained from the extraction unit is introduced into the fixed bed hydrogenation reaction unit through a pipeline for treatment.

35. A catalytic cracking diesel processing system according to claim 26, in, The oil phase material obtained from the resin synthesis unit is introduced into the fluidized bed hydrogenation reaction unit through a pipeline for treatment.

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