A combined hydrogenation process and system for producing chemicals from heavy oil

Abstract

The present invention discloses a combined hydrogenation process and system for producing chemicals from heavy oil. The system comprises a first ebullated-bed reaction zone, a first gas-liquid separator, a second ebullated-bed reaction zone, a second gas-liquid separator, a third gas-liquid separator, a first fractionation unit, a fixed-bed reaction zone, a fourth gas-liquid separation unit, and a second fractionation unit. Also provided is a combined hydrogenation process for producing chemicals from heavy oil, coupling the separation unit, ebullated-bed heavy oil hydrogenation, and fixed-bed hydrogenation to achieve efficient conversion of heavy oil into light and heavy naphtha as primary chemical feedstocks. The process of the present invention organically couples ebullated-bed hydrocracking and fixed-bed hydrocracking, achieving chemical yields exceeding 70%, reducing plant operating severity, and significantly lowering energy consumption and investment.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a combined hydrogenation process for producing chemicals using heavy oil as raw material. Background Art

[0002] The rapid global adoption of new energy vehicles, growing public awareness of shared mobility, and the introduction of environmental protection policies and regulations in relevant countries have significantly slowed the growth of demand for refined products. According to the International Energy Agency, global demand for petrochemicals is expected to grow three to six times faster than fuel over the next five years. Global gasoline demand will grow at a compound annual growth rate of less than 1%, while propylene will increase by approximately 4% and paraxylene by approximately 5%. Reducing oil production and increasing chemical production is the prevailing trend in the current refining industry's transformation. Oil-to-chemicals production remains the dominant route in my country's refining and chemical industry structure.

[0003] Among existing processing routes, hydrogenation offers advantages such as optimized reaction conditions, high yields of target products, and superior quality, making it a clear advantage in converting heavy oil to light chemicals. Currently, leveraging existing, mature technologies and reconfiguring them has significantly increased the yield of basic petrochemical feedstocks to 40%-50%. However, current technologies operate independently using individual units, resulting in poor coupling between these units.

[0004] The dual carbon goals and adjustments to the refining structure have posed new requirements and challenges for hydrogenation technology. Efficiently applying hydrogenation technology to heavy oil-to-chemicals production is an urgent need for development. Throughout the conversion process, it is necessary to strengthen the integrated coupling of logistics and energy flows across various process units, reduce intermediate material and energy consumption, and lower process severity. Developing integrated hydrogenation technology for heavy oil-to-chemicals production will ultimately achieve a green, environmentally friendly, and cost-effective process, facilitating enterprise transformation and upgrading and the adjustment of China's energy structure. Summary of the Invention

[0005] The key to heavy oil-to-chemical hydrogenation technology is how to improve the efficient conversion of heavy oil to naphtha under low severity, provide sufficient raw materials for steam cracking and catalytic reforming-aromatics combined units, and thus increase the production of olefins and aromatic chemicals, while reducing process energy and material consumption. In response to the shortcomings of the existing technology, the main purpose of the present invention is to provide a combined hydrogenation process and system for heavy oil production chemicals, coupling a separation unit, an ebullating bed heavy oil hydrogenation unit, and a fixed bed hydrogenation unit to achieve efficient conversion of heavy oil to chemical raw materials light naphtha and heavy naphtha. In the process flow of the present invention, the various reaction units are efficiently and organically coupled based on the reaction characteristics of different oil products, and the energy consumption and investment of the device are low.

[0006] A first aspect of the present invention provides a combined hydrogenation process for producing chemicals from heavy oil, the combined hydrogenation process comprising the following steps:

[0007] (1) Under contact conditions, heavy oil and hydrogen enter a first ebullated bed reaction zone, and the reaction products are separated to obtain a first gas phase stream and a first liquid phase stream;

[0008] (2) Under contact conditions, the first liquid phase stream and hydrogen obtained in step (1) enter a second ebullated bed reaction zone, and the reaction products are separated to obtain a second gas phase stream and a second liquid phase stream;

[0009] (3) the first gas phase stream obtained in step (1) and the second gas phase stream obtained in step (2) are mixed and separated to obtain a third gas phase stream and a third liquid phase stream;

[0010] (4) the high aromatic fraction, the second liquid phase stream obtained in step (2), and the third liquid phase stream obtained in step (3) are mixed and separated to obtain a first light fraction, a second light fraction, a third light fraction, a middle fraction, and a heavy fraction;

[0011] (5) Under contact conditions, the second light fraction and the middle fraction obtained in step (4), the third gaseous stream obtained in step (3) and hydrogen enter the fixed bed reaction zone for reaction, and the reaction products are separated to obtain a fourth gaseous stream and a fourth liquid stream; wherein the fourth liquid stream is separated to obtain light hydrocarbons, light naphtha, heavy naphtha and hydrogenated heavy oil.

[0012] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the heavy oil in step (1) can be a heavy fraction of crude oil of a certain species and source, such as at least one of atmospheric residue, vacuum residue, deasphalted oil, and asphalt, or a mixed raw material of several of them.

[0013] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the total aromatic content of the high aromatic fraction in step (4) is not less than 55% by mass, and the content of dicyclic and higher ring aromatics is not less than 30% by mass. Preferably, the total aromatic content is higher than 70% by mass, and the content of dicyclic and higher ring aromatics is higher than 40% by mass.

[0014] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the high aromatics fraction in step (4) can be one or more of heavy catalytic diesel from a heavy oil catalytic cracking unit, catalytic cycle oil from a heavy oil catalytic cracking unit, catalytic oil slurry from a heavy oil catalytic cracking unit, ethylene tar fraction from a steam cracking unit, and extracted oil fraction from a furfural extraction unit.

[0015] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the weight ratio of the high aromatic fraction to the heavy oil is 1:20 to 1:4, preferably 1:15 to 1:5.

[0016] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the reaction conditions in the first ebullated bed reaction zone are as follows: reaction temperature of 350-450°C, reaction pressure of 12.0-20.0 MPa, hydrogen-to-oil volume ratio of 300-1000, liquid hourly volume space velocity of 0.1-2.0 h -1 ;

[0017] The preferred reaction conditions of the first ebullated bed reaction zone are as follows: reaction temperature of 380-430°C, reaction pressure of 15.0-19.0 MPa, hydrogen-to-oil volume ratio of 300-800, liquid hourly volume space velocity of 0.15-0.5 h -1 .

[0018] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the reaction conditions in the second ebullated bed reaction zone are as follows: reaction temperature of 350-450°C, reaction pressure of 12.0-20.0 MPa, hydrogen-to-oil volume ratio of 300-1000, liquid hourly volume space velocity of 0.1-2.0 h -1 ;

[0019] The preferred reaction conditions of the second ebullated bed reaction zone are as follows: reaction temperature of 380-430°C, reaction pressure of 15.0-19.0 MPa, hydrogen-to-oil volume ratio of 300-800, liquid hourly volume space velocity of 0.15-0.5 h -1 .

[0020] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the first ebullated bed reaction zone and the second ebullated bed reaction zone can each be equipped with a single ebullated bed reactor, or two or more ebullated bed reactors can be equipped. When two or more ebullated bed reactors are equipped, they are preferably connected in series, and a gas-liquid separator is further provided between the ebullated bed reactors. The ebullated bed reactor can be a reactor with an external circulation cup, or it can be a STRONG ebullated bed reactor with a three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0021] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the ebullated-bed reactors in the first and second ebullated-bed reaction zones are loaded with an ebullated-bed hydrogenation catalyst. The catalyst comprises a support and an active metal, wherein the active metal may be one or more of nickel, cobalt, molybdenum, and tungsten; and the support may be one or more of alumina, alumina-silica, silica, and titanium oxide. The ebullated-bed hydrogenation catalyst may be a commercially available product or prepared according to publicly available methods, such as the FEM-10 or FES-31 ebullated-bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0022] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the third light fraction can be recycled in whole or in part to the first ebullated bed reaction zone for treatment. When a part of it is recycled to the first ebullated bed reaction zone for treatment, the remaining part enters the fixed bed reaction zone for treatment; the cutting temperature between the first light fraction and the second light fraction is 150-250°C, preferably 180-210°C; the cutting temperature between the second light fraction and the third light fraction is 240-330°C, preferably 270-310°C; the cutting temperature between the third light fraction and the middle fraction is 310-400°C, preferably 330-380°C; the cutting temperature between the middle fraction and the heavy fraction is 480-550°C, preferably 500-540°C.

[0023] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the reaction conditions in the fixed bed reaction zone are as follows: reaction temperature of 350-400°C, preferably 360-390°C; hydrogen-to-oil volume ratio of 700-1500, preferably 800-1200; liquid hourly space velocity of 0.5-3.0h -1 , preferably 1.0 to 2.0 hours -1 ; The reaction pressure is 12.0~17.0MPa, preferably 13.0~16.0MPa.

[0024] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the first light fraction obtained in step (4) can be mixed with the light naphtha obtained in step (5) and used as a feedstock for producing ethylene in a steam cracking unit.

[0025] In the above combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the third light fraction obtained in step (4) is circulated to the first ebullated bed reaction zone for treatment.

[0026] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the heavy fraction from step (4) can be recycled to the first ebullated-bed reaction zone and / or the second ebullated-bed reaction zone for processing, or can be discharged as a feedstock for coking, solvent deasphalting, partial oxidation hydrogen production (POX), and other units. Specifically, it can be used as a coking feedstock to produce low-sulfur petroleum coke, or as a feedstock for POX hydrogen production, or it can be fed into a solvent deasphalting unit to generate deasphalted oil and deoiled asphalt, with the deasphalted oil being fed into a hydrocracking unit for processing, and the deoiled asphalt being used as a feedstock for POX hydrogen production.

[0027] In the above combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the light naphtha in step (5) can be used as a raw material for producing ethylene in a steam cracking unit, and the heavy naphtha can be used as an aromatics raw material.

[0028] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the fixed-bed reaction zone can be equipped with a single fixed-bed reactor, or it can be equipped with two or more fixed-bed reactors. Preferably, the two or more fixed-bed reactors are arranged in series, and more preferably, two fixed-bed reactors are arranged in series. When two fixed-bed reactors are used, the first reactor and the second reactor are configured as a refining reactor and a cracking reactor, respectively. The fixed-bed reaction zone can adopt any of a single-stage series single-pass flow, a single-stage series partial-circulation flow, or a single-stage series full-circulation flow, preferably a single-stage series full-circulation flow.

[0029] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific implementation method, when more than two fixed-bed reactors are arranged in the fixed-bed reaction zone, a stripping tower can be set up according to the impurity content in the processed raw materials to remove H2S, NH3, etc. The gas phase obtained by the stripping tower enters the subsequent cold high-separation and circulating hydrogen purification and recovery units for treatment.

[0030] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the fixed-bed reactor in the fixed-bed reaction zone is loaded with a fixed-bed hydrogenation catalyst, specifically a hydrorefining catalyst and / or a hydrocracking catalyst. The catalyst can be a commercially available product or can be prepared in-house using methods disclosed in the prior art.

[0031] In the above-mentioned combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the fourth gaseous phase stream in step (5) is used as circulating hydrogen after purification treatment. The purification treatment generally includes hydrogen purification treatment such as desulfurization treatment and membrane separation. The hydrogen concentration in the hydrogen-rich gas after membrane separation is generally required to reach more than 95%. After being pressurized by a circulating hydrogen compressor, it is circulated to each reaction unit for use as circulating hydrogen.

[0032] In the combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, during separation in the first gas-liquid separator and the second gas-liquid separator, recycled hydrogen and / or new hydrogen are introduced as stripping media to be separated together with the reaction products.

[0033] In the above combined hydrogenation process for producing chemicals from heavy oil, as a specific embodiment, the hydrogenated heavy oil in step (5) is circulated back to the fixed bed reaction zone for treatment.

[0034] A second aspect of the present invention provides a combined hydrogenation system for producing chemicals from heavy oil, the system comprising a first ebullated bed reaction zone, a first gas-liquid separator, a second ebullated bed reaction zone, a second gas-liquid separator, a first fractionation unit, a fixed bed reaction zone, a third gas-liquid separator, a fourth gas-liquid separator, and a second fractionation unit;

[0035] The first ebullated bed reaction zone is used to receive heavy oil feedstock, and the heavy oil is contacted with hydrogen to react;

[0036] a first gas-liquid separator, which is used to receive and separate the reaction product from the first ebullated bed reaction zone to obtain a first gas phase material flow and a first liquid phase material flow after separation;

[0037] a second ebullated bed reaction zone, which is used to receive the first liquid phase stream from the first gas-liquid separator, and the first liquid phase stream is contacted with hydrogen to react;

[0038] a second gas-liquid separator, which is used to receive the reaction product from the second ebullated bed reaction zone and obtain a second gas phase material flow and a second liquid phase material flow after separation;

[0039] a third gas-liquid separator, which is used to receive the first gas-phase material flow from the first gas-liquid separator and the second gas-phase material flow from the second gas-liquid separator, and obtain a third gas-phase material flow and a third liquid-phase material flow after separation;

[0040] a first fractionation unit, which is used to receive the high aromatic fraction, the second liquid phase stream from the second gas-liquid separator, and the third liquid phase stream from the third gas-liquid separator, and obtain a first light fraction, a second light fraction, a third light fraction, a middle fraction, and a heavy fraction after separation;

[0041] a fixed-bed reaction zone, which is used to receive the second light fraction from the first fractionation unit, the middle fraction from the first fractionation unit, and the third gas phase stream from the third gas-liquid separator, and contact them with hydrogen for reaction;

[0042] a fourth gas-liquid separator, which is used to receive the reaction product from the fixed bed reaction zone and obtain a fourth gas phase material flow and a fourth liquid phase material flow after separation;

[0043] The second fractionation unit is used for receiving the fourth liquid phase stream from the fourth gas-liquid separation unit and separating the stream to obtain light hydrocarbons, light naphtha, heavy naphtha and hydrogenated heavy oil.

[0044] In the combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the hydrogenated heavy oil obtained in the second fractionation unit enters the fixed bed reaction zone through a pipeline.

[0045] In the above-mentioned combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the fixed-bed reaction zone can be equipped with a single fixed-bed reactor, or it can be equipped with two or more fixed-bed reactors. Preferably, the two or more fixed-bed reactors are arranged in series, and more preferably, two fixed-bed reactors are arranged in series. When two fixed-bed reactors are used, the first reactor and the second reactor are configured as a refining reactor and a cracking reactor, respectively. The fixed-bed reaction zone can adopt any of a single-stage series single-pass flow, a single-stage series partial-circulation flow, or a single-stage series full-circulation flow, preferably a single-stage series full-circulation flow.

[0046] In the combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the first light fraction obtained from the first fractionation unit can be mixed with the light naphtha obtained from the second fractionation unit and used as a feedstock for producing ethylene in a steam cracking unit.

[0047] In the combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the third light fraction obtained from the first fractionation unit is circulated to the first ebullated bed reaction zone via a pipeline for treatment.

[0048] In the above-mentioned combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the first ebullated bed reaction zone and the second ebullated bed reaction zone can each be equipped with a single ebullated bed reactor, or two or more ebullated bed reactors can be arranged. Preferably, the two or more ebullated bed reactors are arranged in series, and a gas-liquid separator is further provided between the reactors. The ebullated bed reactor can be a reactor with an external circulation cup, or it can be a STRONG ebullated bed reactor with a three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0049] In the above-mentioned combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the heavy fraction from the first fractionation unit can be connected to the first ebullated-bed reaction zone and / or the second ebullated-bed reaction zone via a pipeline for processing therein, or can be discharged via a pipeline to connect to a coking unit, a solvent deasphalting unit, or a POX unit (POX refers to partial oxidation hydrogen production) for use as feed to the unit.

[0050] In the above-mentioned combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the fourth gas phase material flow from the fourth gas-liquid separator is connected to the purification device through a pipeline, and is used as circulating hydrogen after treatment. The purification device generally includes a desulfurization device and a membrane separation device. The hydrogen concentration in the hydrogen-rich gas after membrane separation is generally controlled to reach more than 95%, and is circulated to each reaction unit for use as circulating hydrogen after boosting the pressure through a circulating hydrogen compressor.

[0051] In the combined hydrogenation system for producing chemicals from heavy oil, as a specific embodiment, the outlet of the circulating hydrogen compressor is connected to the first gas-liquid separator and the second gas-liquid separator via a pipeline.

[0052] The technical effects of the combined hydrogenation process and system for producing chemicals from heavy oil provided by the present invention are mainly reflected in the following aspects:

[0053] (1) The combined hydrogenation process and system for producing heavy oil chemicals provided by the present invention utilizes the highly efficient coupling of ebullated-bed and fixed-bed reaction units, fully utilizing the difficulty of hydrogenation conversion of oil molecules. The gaseous components after the ebullated-bed reaction are directly delivered to the subsequent fixed-bed reaction zone, making rational and efficient use of the reaction pressure level and reducing the energy consumption of the device. The hydrogenation units throughout the entire process share a common fractionation system, a circulating hydrogen desulfurization tower, and other equipment, significantly reducing device investment and energy consumption.

[0054] (2) In the combined hydrogenation process and system for producing chemicals from heavy oil provided by the present invention, the high aromatic hydrocarbon fraction is introduced into the first fractionation unit, which has three main advantages: First, the separation device configured in the ebullated bed device itself is cleverly used to perform preliminary separation together with the liquid phase material obtained in the ebullated bed reaction zone, and the third light fraction (2-3 ring aromatic hydrocarbon components) obtained by separation is returned to the first ebullated bed reaction zone. This fraction segment is the heavy diesel fraction. Since the residue oil hydrocracking process follows the dynamic equilibrium theory of reaction, the introduction of the heavy diesel fraction (two parts generated by the ebullated bed itself and introduced from outside) into the reaction system will change the component conversion balance in the residue oil conversion process, thereby increasing the equilibrium conversion rate of the residue oil to the wax oil fraction and the naphtha fraction, reducing the diesel yield, and helping to improve the chemical yield. Secondly, compared with directly introducing the high aromatic fraction into the reaction system, the present invention introduces it into the fractionation unit because the subsequent fractionation unit of the ebullated bed unit is the part most prone to coking. After the high aromatic fraction is added to the hydrogenated oil, the stability of the system will be enhanced, and the aromatics with higher aromatic ring numbers will be retained in the hydrogenated heavy oil, which can significantly slow down the coking problem of the vacuum fractionation system. Thirdly, the two-ring and three-ring aromatics in the high aromatic fraction have a good hydrogen-carrying effect. For example, the naphthalene series in the two-ring aromatics and the anthracene series in the three-ring aromatics can quickly saturate part of the aromatic rings as hydrogen carriers during the ebullated bed hydrogenation process. They can quickly contact with macromolecules such as asphaltene in the residual oil to provide hydrogen molecules, promote asphaltene conversion, improve the residual oil conversion rate, and also enhance the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 The figure is a schematic diagram of the integrated hydrogenation process flow for producing chemicals from heavy oil according to one embodiment of the present invention.

[0056] Among them, 1-heavy oil; 2-first ebullated bed reaction zone; 3-reaction product of the first ebullated bed reaction zone; 4-first gas-liquid separator; 5-first liquid phase stream; 6-second ebullated bed reaction zone; 7-reaction product of the second ebullated bed reaction zone; 8-second gas-liquid separator; 9-second liquid phase stream; 10-first gas phase stream; 11-second gas phase stream; 12-third gas-liquid separator; 13-third liquid phase stream; 14-third gas phase stream; 15-first fractionation unit; 16-first light fraction; 17-second Light fraction; 18-third light fraction; 19-middle fraction; 20-heavy fraction; 21-first reactor of fixed-bed reaction zone; 22-second reactor of fixed-bed reaction zone; 23-products of fixed-bed reaction zone; 24-fourth gas-liquid separator; 25-fourth gas-phase feed stream; 26-circulating hydrogen compressor; 27-circulating hydrogen; 28-new hydrogen; 29-fourth liquid-phase feed stream; 30-second fractionation unit; 31-light hydrocarbons; 32-light naphtha; 33-heavy naphtha; 34-hydrogenated heavy oil, 35-high aromatic fraction.

[0057] Figure 2 Schematic diagram of the process flow of a comparative example of the present invention. DETAILED DESCRIPTION

[0058] Next, the technical features of the present invention will be further described through embodiments and in conjunction with the accompanying drawings, but these embodiments are not intended to limit the present invention.

[0059] Unless expressly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising” will be understood to include the stated elements or components but not to exclude other elements or components.

[0060] In this document, for ease of description, spatially relative terms such as "below," "beneath," "down," "above," "above," etc. may be used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that the spatially relative terms are intended to encompass different orientations of an object in use or operation in addition to the orientation depicted in the drawings. For example, if the object in the figure is turned over, the element described as being "below" or "below" other elements or features will be oriented "above" the element or feature. 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 spatially relative terms used herein should be interpreted accordingly.

[0061] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit specific positions or relative relationships. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable with each other.

[0062]

[0046] 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 precedes the numerical value.

[0063] The present invention provides a combined hydrogenation process for producing chemicals from heavy oil, such as Figure 1 As shown, the specific process flow is as follows: the heavy oil 1 first enters the first ebullated bed reaction zone 2, contacts with the circulating hydrogen 27 and the new hydrogen 28 to react, and the reaction product 3 of the first ebullated bed reaction zone obtained after the reaction enters the first gas-liquid separator 4, and after separation, a first gas-phase material stream 10 and a first liquid-phase material stream 5 are obtained. The first liquid-phase material stream 5 enters the second ebullated bed reaction zone 6, contacts with the circulating hydrogen 27 and the new hydrogen 28 to react, and the reaction product 7 of the second ebullated bed reaction zone obtained after the reaction enters the second gas-liquid separator 8, and after separation, a second gas-phase material stream 11 and a second liquid-phase material stream 9 are obtained, wherein the second gas-phase material stream 11 is mixed with the first gas-phase material stream 10 and enters the third gas-liquid separator 12 for separation to obtain a third gas-phase material stream 14 and a third liquid-phase material stream 13, and the second liquid-phase material stream 9, the third liquid-phase material stream 13 and the optional high aromatic hydrocarbon fraction 35 are mixed and enter the first fractionation unit 15 for separation A first light fraction 16, a second light fraction 17, a third light fraction 18, an intermediate fraction 19 and a heavy fraction 20 are obtained; the third light fraction 18 is returned to the first ebullated bed reaction zone 2 for treatment; the second light fraction 17, the intermediate fraction 19 and the third gaseous stream 14 are sequentially fed into the first reactor 21 and the second reactor 22 of the fixed bed reaction zone for reaction. The product 23 of the fixed bed reaction zone obtained after the reaction enters the fourth gas-liquid separator 24, and after separation, a fourth gaseous stream 25 and a fourth liquid stream 29 are obtained. The fourth gaseous stream 25 is purified (the purification device is not shown in the figure) and then pressurized by a circulating hydrogen compressor 26 to obtain circulating hydrogen 27. The circulating hydrogen 27 is returned to the reaction system. The fourth liquid stream 29 enters the second fractionation unit 30 for separation to obtain light hydrocarbons 31, light naphtha 32, heavy naphtha 33 and hydrogenated heavy oil 34, of which the hydrogenated heavy oil 34 is returned to the fixed bed unit for treatment.

[0064] In this paper, the ebullated bed reactor adopts the STRONG ebullated bed reactor with built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0065] In this paper, the properties of heavy oil are shown in Table 1, and the high aromatic fraction comes from the catalytic cracking unit, and its properties are shown in Table 2.

[0066] Table 1 Heavy oil properties

[0067] project heavy oil <![CDATA[Density (20 °C), g / cm 3 > 1.021 Viscosity, (150℃), mPa·s 89.0 Carbon residue, wt% 19.4 Sulfur content, wt% 4.83 Nitrogen content, wt% 0.36 Metal (Ni+V), mg / kg 213.0 Gum, wt% 15.93 Asphaltene, wt% 12.96

[0068] Table 2 High aromatic fractions

[0069] project data <![CDATA[Density at 20 °C, kg / m 3 > 1058 S，％ 1.17 N, mg / kg 1800 Distillation range distribution Initial distillation point, ℃ 270 10％ / 30％，℃ 312 / 343 50％ / 70％，℃ 369 / 394 90％，℃ 418 Final distillation point, ℃ 442 Hydrocarbon composition, wt% Alkanes 13.2 Total cycloalkanes 6.7 Total monocyclic aromatic hydrocarbons 19.1 Total bicyclic aromatic hydrocarbons 46.3 tricyclic aromatic hydrocarbons 14.7 Total aromatics 78.1

[0070] Example 1

[0071] Example 1 uses Figure 1 The process flow is shown.

[0072] The mass ratio of the high aromatic fraction introduced to the heavy oil entering the first ebullated bed reaction zone is 1:5, and the third light fraction accounts for 10% of the mass fraction of the total feed to the first ebullated bed reaction zone.

[0073] The first ebullated bed reaction zone and the second ebullated bed reaction zone adopt a dual-reactor series mode. The catalyst loaded in the first ebullated bed reaction zone is FEM-10 ebullated bed hydrogenation catalyst, and the catalyst loaded in the second ebullated bed reaction zone is FES-31 ebullated bed hydrogenation catalyst.

[0074] The reaction pressures of the first and second ebullated bed reaction zones were both 17 MPa, the hydrogen-to-oil volume ratio was 400, and the total volumetric space velocity of the ebullated bed was 0.24 h-1. -1 The reaction temperature of the first ebullated bed reaction zone is 418°C, and the reaction temperature of the second ebullated bed reaction zone is 422°C.

[0075] The cutting temperature between the first light fraction and the second light fraction is 180°C, the cutting temperature between the second light fraction and the third light fraction is 300°C, the cutting temperature between the third light fraction and the middle fraction is 360°C, and the cutting temperature between the middle fraction and the heavy fraction is 510°C.

[0076] The first reactor in the fixed-bed reaction zone is filled with FF-56 pretreatment catalyst, and the second reactor is filled with FC-76 hydrocracking catalyst and FF-34 hydrofining catalyst. The reaction conditions of the first reactor in the fixed-bed reaction zone are: reaction pressure of 16.0 MPa, reaction temperature of 368°C, volume space velocity of 1.5 h -1 , the hydrogen-oil volume ratio is 800; the reaction conditions of the second reactor are: reaction pressure of 15.0MPa, reaction temperature of 380℃, volume space velocity of 1.7h -1 , the hydrogen-to-oil volume ratio is 1000.

[0077] Example 2

[0078] Example 2 also uses Figure 1 The process flow is basically the same as that of Example 1, except that the mass ratio of the introduced catalytic diesel to the heavy oil is 1:10, and the third light fraction accounts for 10% of the mass fraction of the total feed to the first ebullated bed reaction zone.

[0079] The first ebullated bed reaction zone and the second ebullated bed reaction zone adopt a dual-reactor series mode. The catalyst loaded in the first ebullated bed reaction zone is FEM-10 ebullated bed hydrogenation catalyst, and the catalyst loaded in the second ebullated bed reaction zone is FES-31 ebullated bed hydrogenation catalyst.

[0080] The reaction pressures of the first and second ebullated bed reaction zones were both 17 MPa, the hydrogen-to-oil volume ratio was 500, and the total volumetric space velocity of the ebullated bed was 0.22 h -1 The reaction temperature of the first ebullated bed reaction zone is 423°C, and the reaction temperature of the second ebullated bed reaction zone is 428°C.

[0081] The cutting temperature between the first light fraction and the second light fraction is 180°C, the cutting temperature between the second light fraction and the third light fraction is 300°C, the cutting temperature between the third light fraction and the middle fraction is 360°C, and the cutting temperature between the middle fraction and the heavy fraction is 510°C.

[0082] The first reactor in the fixed-bed reaction zone is filled with FF-56 pretreatment catalyst, and the second reactor is filled with FC-76 hydrocracking catalyst and FF-34 hydrofining catalyst. The reaction conditions of the first reactor in the fixed-bed reaction zone are: reaction pressure of 16.0 MPa, reaction temperature of 368°C, volume space velocity of 1.5 h -1 , the hydrogen-oil volume ratio is 800; the reaction conditions of the second reactor are: reaction pressure of 14.0MPa, reaction temperature of 380℃, volume space velocity of 1.7h -1 , the hydrogen-to-oil volume ratio is 1000.

[0083] Example 3

[0084] Example 3 also uses Figure 1 The process flow is basically the same as that of Example 2, except that the mass ratio of the introduced catalytic diesel to the heavy oil is 1:10, and the third light fraction accounts for 10% of the mass fraction of the total feed to the first ebullated bed reaction zone.

[0085] The first ebullated bed reaction zone and the second ebullated bed reaction zone adopt a dual-reactor series mode. The catalyst loaded in the first ebullated bed reaction zone is FEM-10 ebullated bed hydrogenation catalyst, and the catalyst loaded in the second ebullated bed reaction zone is FES-31 ebullated bed hydrogenation catalyst.

[0086] The reaction pressures of the first and second ebullated bed reaction zones were both 15 MPa, the hydrogen-to-oil volume ratio was 400, and the total volumetric space velocity of the ebullated bed was 0.20 h -1 The reaction temperature of the first ebullated bed reaction zone is 423°C, and the reaction temperature of the second ebullated bed reaction zone is 428°C.

[0087] The cutting temperature between the first light fraction and the second light fraction is 180°C, the cutting temperature between the second light fraction and the third light fraction is 320°C, the cutting temperature between the third light fraction and the middle fraction is 370°C, and the cutting temperature between the middle fraction and the heavy fraction is 510°C.

[0088] The first reactor in the fixed-bed reaction zone is filled with FF-56 pretreatment catalyst, and the second reactor is filled with FC-76 hydrocracking catalyst and FF-34 hydrofining catalyst. The reaction conditions of the first reactor in the fixed-bed reaction zone are: reaction pressure of 14.0 MPa, reaction temperature of 365°C, volume space velocity of 1.4 h -1 , the hydrogen-oil volume ratio is 800; the reaction conditions of the second reactor are: reaction pressure of 16.0 MPa, reaction temperature of 376 ° C, volume space velocity of 1.8 h -1 , the hydrogen-to-oil volume ratio is 1200.

[0089] Comparative Example 1

[0090] Comparative Example 1 Figure 2 The process flow chart shown in the figure is different from that in the embodiment in that the circulating hydrogen pressure systems of the ebullated bed hydrogenation unit and the fixed bed hydrogenation unit are separated, and no high aromatic fraction is introduced.

[0091] The heavy oil 1 is mixed with the circulating hydrogen 16 and the new hydrogen 33 and enters the first ebullated bed reaction zone 2. The reaction product oil 3 enters the first gas-liquid separator 4 and is separated to obtain the first gas phase material stream 8 and the first liquid phase material stream 5. The first liquid phase material stream 5 is mixed with the circulating hydrogen 16 and enters the second ebullated bed reaction zone 6. The product oil 7 obtained after the reaction enters the second gas-liquid separator 9 and is separated to obtain the second gas phase material stream 11 and the second liquid phase material stream 10. The first gas phase material stream 8 and the second gas phase material stream 11 are mixed and enter the third gas-liquid separator 12 to be separated into the third gas phase material stream 14 and the third liquid phase material stream 13. The third gas phase material stream 14 is purified and recovered by hydrogen and then compressed by the first circulating hydrogen compressor 15 to obtain circulating hydrogen. The second liquid phase material stream 10 and the third liquid phase material stream 13 are separated. The mixed phase stream 13 enters the first fractionation unit 17 to be separated into a first light fraction, a second light fraction, a middle fraction and a heavy fraction, wherein the second light fraction and the middle fraction enter the first reactor 22 and the second reactor 23 of the fixed bed reaction zone in sequence, and the reaction generated oil enters the fourth gas-liquid separator 24 to be separated to obtain a fourth gas phase stream 25 and a fourth liquid phase stream 28. After purification and recovery, the fourth gas phase stream 25 passes through the second circulating hydrogen compressor 27 to obtain circulating hydrogen for the fixed bed reaction zone, and the fourth liquid phase stream 28 enters the second fractionation unit 26 to be separated to obtain light hydrocarbons 29, light naphtha 30, heavy naphtha 31 and hydrogenated heavy oil 32, wherein the hydrogenated heavy oil 32 is returned to the first reactor 22 of the fixed bed reaction zone for treatment.

[0092] The first ebullated bed reaction zone and the second ebullated bed reaction zone adopt a dual-reactor series mode. The catalyst loaded in the first ebullated bed reaction zone is FEM-10 ebullated bed hydrogenation catalyst, and the catalyst loaded in the second ebullated bed reaction zone is FES-31 ebullated bed hydrogenation catalyst.

[0093] The reaction pressures of the first and second ebullated bed reaction zones were both 17 MPa, the hydrogen-to-oil volume ratio was 500, and the total volumetric space velocity of the ebullated bed was 0.20 h -1 The reaction temperature of the first ebullated bed reaction zone is 423°C, and the reaction temperature of the second ebullated bed reaction zone is 428°C.

[0094] The cutting temperature between the first light fraction and the second light fraction is 180°C, the cutting temperature between the second light fraction and the middle fraction is 350°C, and the cutting temperature between the middle fraction and the heavy fraction is 510°C.

[0095] The first reactor in the fixed-bed reaction zone is filled with FF-56 pretreatment catalyst, and the second reactor is filled with FC-76 hydrocracking catalyst and FF-34 hydrofining catalyst. The reaction conditions of the first reactor in the fixed-bed reaction zone are: reaction pressure of 16.0 MPa, reaction temperature of 365°C, volume space velocity of 1.4 h -1 , the hydrogen-oil volume ratio is 800; the reaction conditions of the second reactor are: reaction pressure of 16.0 MPa, reaction temperature of 380 ° C, volume space velocity of 1.6 h -1 , the hydrogen-to-oil volume ratio is 1000.

[0096] The comparative results of the embodiments and comparative examples are shown in Tables 2 and 3.

[0097] Table 2 Product distribution

[0098]

[0099]

[0100] Table 3 Properties of Hydrogenated Heavy Oil

[0101] project Example 1 Example 2 Example 3 Comparative Example 1 <![CDATA[Density (20 °C), kg / m 3 > 967.9 973.3 979.2 986.2 S, wt% 0.82 1.01 1.14 1.39 N, mg / kg 3219 3332 3700 4012 Carbon residue, wt% 18.56 20.21 22.51 22.51 Metal Ni+V, mg / kg 64 67 86 96

Claims

1. A combined hydrogenation process for producing chemicals from heavy oil, the combined hydrogenation process comprising the following steps: (1) Under contact conditions, heavy oil and hydrogen enter the first ebullated bed reaction zone, and the reaction products are separated to obtain a first gas phase stream and a first liquid phase stream; (2) Under contact conditions, the first liquid phase stream and hydrogen obtained in step (1) enter the second ebullated bed reaction zone, and the reaction products are separated to obtain a second gas phase stream and a second liquid phase stream; (3) the first gas phase stream obtained in step (1) and the second gas phase stream obtained in step (2) are mixed and separated to obtain a third gas phase stream and a third liquid phase stream; (4) The high aromatic fraction, the second liquid phase stream obtained in step (2) and the third liquid phase stream obtained in step (3) are mixed and separated to obtain a first light fraction, a second light fraction, a third light fraction, an intermediate fraction and a heavy fraction; the third light fraction is recycled in whole or in part to the first ebullated bed reaction zone for treatment; the total aromatic content of the high aromatic fraction is not less than 55% by mass, and the content of dicyclic and higher ring aromatics is not less than 30% by mass; the cutting temperature of the first light fraction and the second light fraction is 150-250°C, the cutting temperature of the second light fraction and the third light fraction is 240-330°C, the cutting temperature of the third light fraction and the intermediate fraction is 310-400°C, and the cutting temperature of the intermediate fraction and the heavy fraction is 480-550°C; (5) Under the contact conditions, the second light fraction and the middle fraction obtained in step (4), the third gaseous stream obtained in step (3) and hydrogen enter the fixed bed reaction zone for reaction, and the reaction products are separated to obtain a fourth gaseous stream and a fourth liquid stream; wherein the fourth liquid stream is separated to obtain light hydrocarbons, light naphtha, heavy naphtha and hydrogenated heavy oil.

2. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The heavy oil in step (1) is a heavy fraction of crude oil of different species and sources, and is selected from at least one of atmospheric residue, vacuum residue, deasphalted oil, and asphalt.

3. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The total aromatic content of the high aromatic fraction in step (4) is higher than 70% by mass, and the content of dicyclic and higher ring aromatics is higher than 40% by mass.

4. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The weight ratio of the high aromatic fraction to the heavy oil is 1:20 to 1:

4.

5. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The weight ratio of the high aromatic fraction to the heavy oil is 1:15 to 1:

5.

6. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions of the first ebullated bed reaction zone are as follows: reaction temperature of 350-450°C, reaction pressure of 12.0-20.0 MPa, hydrogen-to-oil volume ratio of 300-1000, liquid hourly volume space velocity of 0.1-2.0 h -1 .

7. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions of the first ebullated bed reaction zone are as follows: reaction temperature of 380-430°C, reaction pressure of 15.0-19.0 MPa, hydrogen-to-oil volume ratio of 300-800, liquid hourly volume space velocity of 0.15-0.5 h -1 .

8. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions of the second ebullated bed reaction zone are as follows: reaction temperature of 350-450°C, reaction pressure of 12.0-20.0 MPa, hydrogen-to-oil volume ratio of 300-1000, liquid hourly volume space velocity of 0.1-2.0 h -1 .

9. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions of the second ebullated bed reaction zone are as follows: reaction temperature of 380-430°C, reaction pressure of 15.0-19.0 MPa, hydrogen-to-oil volume ratio of 300-800, liquid hourly volume space velocity of 0.15-0.5 h -1 .

10. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: When part of the third light fraction is recycled back to the first ebullated bed reaction zone for treatment, the remaining part enters the fixed bed reaction zone for treatment.

11. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The cutting temperature of the first light fraction and the second light fraction is 180-210°C, the cutting temperature of the second light fraction and the third light fraction is 270-310°C, the cutting temperature of the third light fraction and the middle fraction is 330-380°C, and the cutting temperature of the middle fraction and the heavy fraction is 500-540°C.

12. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions in the fixed bed reaction zone are as follows: reaction temperature 350-400°C, hydrogen to oil volume ratio 700-1500, liquid hourly volume space velocity 0.5-3.0h -1 , the reaction pressure is 12.0~17.0MPa.

13. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The reaction conditions in the fixed bed reaction zone are as follows: reaction temperature of 360-390°C, hydrogen to oil volume ratio of 800-1200, liquid hourly volume space velocity of 1.0-2.0h -1 , the reaction pressure is 13.0~16.0MPa.

14. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The first light fraction obtained in step (4) is mixed with the light naphtha obtained in step (5) and used as a raw material for the steam cracking unit to produce ethylene.

15. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The heavy fraction in step (4) is recycled to the first ebullated bed reaction zone and / or the second ebullated bed reaction zone for treatment, or discharged as a feedstock for a coking, solvent deasphalting, or partial oxidation hydrogen production unit.

16. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The fourth gaseous phase stream in step (5) is used as circulating hydrogen after being purified, and is pressurized by a circulating hydrogen compressor and circulated to each reaction zone for use as circulating hydrogen.

17. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: During separation in the first gas-liquid separator and the second gas-liquid separator, circulating hydrogen and / or new hydrogen are introduced as stripping media to be separated together with the reaction product materials.

18. The combined hydrogenation process for producing chemicals from heavy oil according to claim 1, characterized in that: The hydrogenated heavy oil in step (5) is circulated back to the fixed bed reaction zone for treatment.

19. A hydrogenation system for implementing the combined hydrogenation process for producing chemicals from heavy oil as claimed in any one of claims 1 to 18, the system comprising a first ebullated bed reaction zone, a first gas-liquid separator, a second ebullated bed reaction zone, a second gas-liquid separator, a first fractionation unit, a fixed bed reaction zone, a third gas-liquid separator, a fourth gas-liquid separator, and a second fractionation unit; The first ebullated bed reaction zone is used to receive heavy oil feedstock, and the heavy oil is contacted with hydrogen to react; a first gas-liquid separator, which is used to receive and separate the reaction product from the first ebullated bed reaction zone to obtain a first gas phase material flow and a first liquid phase material flow after separation; a second ebullated bed reaction zone, which is used to receive the first liquid phase stream from the first gas-liquid separator, and the first liquid phase stream is contacted with hydrogen to react; a second gas-liquid separator, which is used to receive the reaction product from the second ebullated bed reaction zone and obtain a second gas phase material flow and a second liquid phase material flow after separation; a third gas-liquid separator, which is used to receive the first gas-phase material flow from the first gas-liquid separator and the second gas-phase material flow from the second gas-liquid separator, and obtain a third gas-phase material flow and a third liquid-phase material flow after separation; a first fractionation unit, which is used to receive the high aromatic fraction, the second liquid phase stream from the second gas-liquid separator, and the third liquid phase stream from the third gas-liquid separator, and obtain a first light fraction, a second light fraction, a third light fraction, a middle fraction, and a heavy fraction after separation; a fixed-bed reaction zone, which is used to receive the second light fraction from the first fractionation unit, the middle fraction from the first fractionation unit, and the third gas phase stream from the third gas-liquid separator, and contact them with hydrogen for reaction; a fourth gas-liquid separator, which is used to receive the reaction product from the fixed bed reaction zone and obtain a fourth gas phase material flow and a fourth liquid phase material flow after separation; The second fractionation unit is used for receiving the fourth liquid phase stream from the fourth gas-liquid separation unit and separating the stream to obtain light hydrocarbons, light naphtha, heavy naphtha and hydrogenated heavy oil.

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