A combined processing technology and system for treating inferior hydrocarbon-containing raw materials

Abstract

This invention discloses a combined processing technology and system for treating low-quality hydrocarbon-containing feedstocks. The combined processing technology includes the following steps: hydrocarbon-containing feedstocks and hydrogen gas are sequentially introduced into a two-stage fluidized bed reaction zone arranged in series for reaction. The reaction products are separated to obtain gas, hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil, and unconverted oil. The unconverted oil is then introduced into a coking reaction zone, where it reacts to obtain petroleum coke, coking gas, coked naphtha, coked diesel, coked light wax oil, coked heavy wax oil, and coking cycle oil. The combined process provided by this invention organically couples hydrotreating and decarbonization processes to achieve efficient conversion of low-quality heavy oil.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, and in particular relates to a method and system for treating inferior hydrocarbon-containing raw materials using a combined process. Background Technology

[0002] In recent years, the deep processing of low-quality heavy oil has become a key focus of technological development in the oil refining industry, mainly including hydrotreating and decarbonization technologies. Among them, fluidized bed heavy oil hydrotreating technology has significant advantages in the light processing of heavy oil, with advantages such as online catalyst replacement, high utilization rate, long operating cycle, and flexible unit operation. It can meet the requirements of large-scale units and long-cycle operation, and plays a crucial role in the current refining and chemical transformation process.

[0003] In the fluidized bed residue hydrotreating process, the residue oil conversion rate is typically between 60% and 80%, leaving a considerable proportion of unconverted oil that requires processing. The efficiency of its utilization directly impacts the economics of the fluidized bed hydrotreating process. While increasing the conversion rate can reduce the unconverted oil yield to some extent, it significantly increases the operational demands of the fluidized bed hydrotreating unit, increases catalyst consumption, and affects the long-term stable operation of the unit. Therefore, optimizing the processing technology based on the characteristics of the unconverted oil, and establishing a coupling technology between fluidized bed hydrotreating and other processes, is currently the main research direction.

[0004] CN 103102986 A discloses a combined process of residue oil hydrotreating and delayed coking. In this method, residue oil, coking wax oil, and hydrogen are fed together into a hydrotreating unit. The hydrotreated residue oil is then mixed with separated vacuum gas oil and fed into a delayed coking unit to separate coking products. All coking gas oil is recycled back to the residue oil hydrotreating unit. While the hydrotreated vacuum gas oil has superior properties, using it as a coking feedstock generates dry gas and petroleum coke, resulting in a lower overall liquid yield, reduced economic efficiency, and an inability to significantly improve the hydrotreating effect of the unit.

[0005] CN103059998A discloses a combined process for treating residual oil. In this method, the liquid phase product from the residual oil feedstock after fluidized bed hydrotreatment is directly fed into a coking fractionation tower without fractionation. There, it comes into counter-current contact with coking gas and is fractionated to obtain a wax oil fraction, which then enters a wax oil hydrotreatment unit. The resulting liquid phase product is used as feedstock for catalytic cracking. The circulating oil obtained from the coking fractionation tower is returned to the delayed coking unit. This process requires separate refining of the coking wax oil fraction. Since coking wax oil has high nitrogen content, high-pressure hydrotreatment is necessary, increasing the investment cost of the equipment. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a combined processing technology and system for treating inferior hydrocarbon-containing feedstocks. This combined processing technology enables the efficient coupling of fluidized bed hydrogenation, catalytic cracking, and coking processes, thereby achieving the efficient conversion of inferior hydrocarbon-containing feedstocks.

[0007] I. This invention provides a combined processing technology for inferior hydrocarbon-containing raw materials, the combined processing technology including the following steps:

[0008] (1) Hydrocarbon-containing raw materials and hydrogen are sequentially introduced into the first and second fluidized bed reaction zones set in series for reaction. The reaction products are separated to obtain gas, hydrogenated naphtha, hydrogenated diesel, hydrogenated wax oil and unconverted oil.

[0009] (2) The unconverted oil obtained in step (1) enters the coking reaction zone, reacts and is separated to obtain petroleum coke, coking gas, coking naphtha, coking diesel, coking light wax oil, coking heavy wax oil and coking circulating oil; wherein, the coking light wax oil is partially or completely recycled back to the second fluidized bed reaction zone, and the coking heavy wax oil is partially or completely recycled back to the first fluidized bed reaction zone.

[0010] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, a gas-liquid separator may or may not be installed between the first and second fluidized bed reaction zones. When a gas-liquid separator is installed, the reaction products in the first fluidized bed reaction zone are separated to obtain gas-liquid flow and liquid flow, and the liquid flow enters the second fluidized bed reaction zone for processing.

[0011] Furthermore, in the above-mentioned inferior hydrocarbon feedstock combination processing process, the hydrogenated wax oil obtained in step (1) enters the catalytic cracking reaction zone for reaction, and after the reaction, cracked gas, catalytic gasoline, catalytic diesel, catalytic cycle oil and catalytic slurry are obtained.

[0012] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, under preferred conditions, the catalytic cycle oil and coking heavy wax oil are mixed and returned to the first fluidized bed reaction zone for further processing after being filtered and separated.

[0013] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, in a preferred case, the catalytic slurry can be processed in the first fluidized bed reaction zone and / or the coking reaction zone. More preferably, a portion is processed in the first fluidized bed reaction zone, and the remaining portion is processed in the coking reaction zone.

[0014] Furthermore, in the above-mentioned combined treatment process of inferior hydrocarbon raw materials, the coking circulating oil obtained in step (2) can be recycled back to the coking reaction zone for further treatment.

[0015] Furthermore, in the above-mentioned combined processing technology for inferior hydrocarbon feedstocks, the hydrotreated naphtha obtained in step (1), the coking naphtha obtained in step (2), and the catalytic gasoline obtained in the catalytic cracking reaction zone can optionally be used as ethylene feedstock or aromatic feedstock after hydrorefining.

[0016] Furthermore, in the above-mentioned combined processing technology for inferior hydrocarbon feedstocks, the hydrotreated diesel obtained in step (1), the coking diesel obtained in step (2), and the catalytic diesel obtained in the catalytic cracking reaction zone can be subjected to hydrocracking treatment.

[0017] Furthermore, in the above-mentioned inferior hydrocarbon raw material combination treatment process, the hydrocarbon raw material mentioned in step (1) can be selected from one or more of atmospheric residue, vacuum residue, oilfield heavy oil, heavy fuel oil, etc., and can also be optionally blended or not blended with one or more of catalytic slurry, vacuum wax oil, furfural extract oil.

[0018] Furthermore, in the aforementioned combined treatment process for inferior hydrocarbon-containing feedstocks, both the first and second fluidized bed reaction zones are equipped with at least one fluidized bed hydrogenation reactor. The fluidized bed reactor can be at least one of existing fluidized bed reactors, specifically a fluidized bed reactor with a circulating cup, or the STRONG fluidized bed reactor with a built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with the STRONG fluidized bed reactor with a built-in three-phase separator being preferred. When using a fluidized bed reactor with a circulating cup, a device with gas-liquid separation function needs to be installed between the first and second fluidized bed reaction zones, such as a high-pressure separator. Its main purpose is to separate the hydrogen and light hydrocarbon components from the heavy fraction in the reaction products of the first fluidized bed reactor.

[0019] Furthermore, in the above-mentioned combined processing technology for inferior hydrocarbon-containing raw materials, the separation process of the reaction products in the second fluidized bed reaction zone is as follows: the reaction products obtained from the second fluidized bed reaction zone first enter the first gas-liquid separator, and the first gas phase stream and the first liquid phase stream are separated; the first gas phase stream and the gas phase stream obtained from the first fluidized bed reaction zone (optionally) enter the second gas-liquid separator, and after separation, the second gas phase stream and the second liquid phase stream are obtained; the first liquid phase stream enters the third gas-liquid separator, and after separation, the third gas phase stream and the third liquid phase stream are obtained; the second gas phase stream and the third gas phase stream are mixed and enter the hydrogen recovery unit for processing to obtain recycled hydrogen; the second liquid phase stream and the third liquid phase stream enter the first fractionation tower for separation to obtain hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil and unconverted oil.

[0020] Furthermore, in the aforementioned combined treatment process for inferior hydrocarbon-containing raw materials, the operating conditions of the first fluidized bed reaction zone are as follows: reaction temperature of 350–450℃, preferably 380–430℃; reaction pressure of 10.0–20.0 MPa, preferably 15.0–18.0 MPa; hydrogen-to-oil volume ratio of 300–1000, preferably 400–600; and liquid hourly space velocity of 0.1–5.0 h⁻¹. -1 Preferably, it is 0.2 to 0.5 h. -1 .

[0021] Furthermore, in the aforementioned combined treatment process for inferior hydrocarbon-containing feedstocks, the operating conditions of the second fluidized bed reaction zone are as follows: reaction temperature of 350–450℃, preferably 380–430℃; reaction pressure of 10.0–20.0 MPa, preferably 15.0–18.0 MPa; hydrogen-to-oil volume ratio of 300–1000, preferably 400–600; and liquid hourly space velocity of 0.1–5.0 h⁻¹. -1 Preferably, it is 0.2 to 0.5 h. -1 .

[0022] Furthermore, in the aforementioned combined treatment process for inferior hydrocarbon-containing feedstocks, both the first and second fluidized bed reaction zones are filled with fluidized bed hydrogenation catalysts, which can be the same or different. Moreover, when the catalyst activity in the second fluidized bed reaction zone decreases to a certain level, the catalyst from the second fluidized bed reaction zone is discharged into the first fluidized bed reaction zone for use through an online catalyst addition and discharge process. If different types of catalysts are used in the first and second fluidized bed reaction zones, the average pore size of the catalyst in the first fluidized bed reaction zone should be higher than that in the second fluidized bed reaction zone. The filled fluidized bed hydrogenation catalyst can be a commercial catalyst or prepared according to existing technical methods, such as the series of fluidized bed hydrogenation catalysts developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd. Generally, the catalyst includes a support and an active metal component, wherein the active metal is a Group VIB and / or Group VIII metal, specifically one or more of nickel, cobalt, molybdenum, or tungsten; the support can be one or more of alumina, silica, alumina-silica, or titanium dioxide.

[0023] Furthermore, in the above-mentioned combined processing technology for inferior hydrocarbon-containing raw materials, the cutting point of hydrogenated wax oil and unconverted oil is 450-550℃, preferably 500-540℃.

[0024] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, the coking reaction zone in step (2) includes at least one heating furnace, two coking towers and one fractionation tower; it includes two processes: continuous coking and intermittent coking removal; under normal circumstances, the outlet temperature of the heating furnace is 480-520℃, preferably 490-510℃; the pressure of the coking tower is 0.1MPa-0.5MPa, preferably 0.15-0.25MPa; and the recycle ratio is 0.05-1.0, preferably 0.1-0.3.

[0025] Furthermore, in the above-mentioned inferior hydrocarbon raw material combination treatment process, the cutting point temperature of coking light wax oil and coking heavy wax oil in step (2) is 400-450℃, preferably 410℃-430℃; the cutting point temperature of coking heavy wax oil and coking circulating oil is 490℃-540℃, preferably 500℃-520℃.

[0026] Furthermore, in the aforementioned combined processing technology for inferior hydrocarbon-containing raw materials, when part of the coking light wax oil is recycled back to the second fluidized bed reaction zone, the remaining part of the coking light wax oil can be mixed with hydrogenated wax oil as a downstream processing raw material.

[0027] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, when the coking heavy wax oil is recycled back to the first fluidized bed reaction zone, a coking powder filter is installed on the return pipeline, wherein the filter can be at least one of a backwash filter and a ceramic membrane filter; the coking powder content in the purified coking wax oil is controlled to be no more than 0.01 wt%.

[0028] Furthermore, in the aforementioned combined processing technology for inferior hydrocarbon feedstocks, coking light wax oil and / or coking heavy wax oil can also be used as transport oil for the fluidized bed hydrogenation catalyst in the first fluidized bed reaction zone and the second fluidized bed reaction zone, and returned to the corresponding fluidized bed reactor in a manner that carries the fluidized bed catalyst.

[0029] Furthermore, in the aforementioned combined treatment process for inferior hydrocarbon feedstocks, the catalytic cracking catalyst packed in the catalytic cracking reaction zone can be prepared using commercially available products or existing publicly disclosed methods.

[0030] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon feedstock, the reaction conditions in the catalytic cracking reaction zone are as follows: the reaction temperature is 480–550℃, preferably 490–510℃; the mass ratio of steam to feed is 0.05:1–1:1, preferably 0.05:1:1–0.5:1; the reaction pressure is 0.10–1.0 MPa, preferably 0.10–0.5 MPa; and the contact time with the catalyst is 0.1–15.0 seconds, preferably 0.5–5.0 seconds.

[0031] Furthermore, in the above-mentioned combined treatment process for inferior hydrocarbon-containing raw materials, the cut-off temperature of catalytic gasoline and catalytic diesel is 180-240℃, preferably 200-220℃; the cut-off temperature of catalytic diesel and catalytic cycle oil is 320-380℃, preferably 340-370℃; and the cut-off temperature of catalytic cycle oil and catalytic slurry is 410-470℃, preferably 430-460℃.

[0032] A second aspect of the present invention provides a combined processing system for inferior hydrocarbon-containing raw materials, the combined processing system comprising a fluidized bed reaction zone and a coking reaction zone;

[0033] The fluidized bed reaction zone includes a first fluidized bed reaction zone and a second fluidized bed reaction zone arranged in series. It is used to receive hydrocarbon-containing raw materials and hydrogen gas, and the hydrocarbon-containing raw materials and hydrogen gas undergo a hydrogenation reaction after contact.

[0034] The first separation system includes a gas-liquid separation unit and a first fractionation unit, which is used to receive and separate the reaction products from the fluidized bed reaction zone, and obtain gas, hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil and unconverted oil after separation.

[0035] The coking reaction zone is used to receive unconverted oil from the separation system. The unconverted oil undergoes a coking reaction, and the reaction yields petroleum coke, gaseous and liquid fractions.

[0036] The second separation system is used to receive and separate the liquid phase fraction from the coking reaction zone, and the separated fractions are coking naphtha, coking diesel, coking light wax oil, coking heavy wax oil and coking cycle oil.

[0037] Furthermore, in the aforementioned combined processing system for inferior hydrocarbon-containing feedstocks, coking light wax oil is connected to the second fluidized bed reaction zone via pipeline.

[0038] Furthermore, in the aforementioned combined processing system for inferior hydrocarbon-containing raw materials, the coking heavy wax oil is connected to the first fluidized bed reaction zone via pipeline.

[0039] Furthermore, the aforementioned inferior hydrocarbon feedstock combined processing system also includes a catalytic cracking reaction zone, which is used to receive hydrogenated wax oil from the first separation system. After the hydrogenated wax oil undergoes a catalytic cracking reaction, it yields cracked gas, catalytic gasoline, catalytic diesel, catalytic cycle oil, and catalytic slurry.

[0040] Furthermore, in the aforementioned combined treatment system for inferior hydrocarbon-containing feedstocks, the catalytic circulating oil is connected to the coking heavy wax oil pipeline via a pipeline, and is also connected to the first fluidized bed reaction zone via a pipeline. Preferably, a separation device is installed on the pipeline, and the separation device is a filter, wherein the filter can be at least one of a backwash filter and a ceramic membrane filter.

[0041] Furthermore, in the aforementioned combined treatment system for inferior hydrocarbon feedstocks, the catalytic slurry is connected to the first fluidized bed reaction zone and / or the coking reaction zone via pipelines. More preferably, a portion of the catalytic slurry is connected to the first fluidized bed reaction zone via pipelines, and the remaining portion of the catalytic slurry is connected to the coking reaction zone via pipelines.

[0042] Furthermore, in the aforementioned combined processing system for inferior hydrocarbon-containing raw materials, the coking reaction zone includes at least one heating furnace, two coking towers, and one fractionation tower, comprising two processes: continuous coking and intermittent decoking.

[0043] Furthermore, in the aforementioned combined treatment system for inferior hydrocarbon-containing feedstocks, the coking circulating oil is connected to the inlet of the coking reaction zone via pipeline.

[0044] Furthermore, in the aforementioned combined processing system for inferior hydrocarbon feedstocks, both the first and second fluidized bed reaction zones are equipped with at least one fluidized bed hydrogenation reactor. The fluidized bed reactor can be at least one of existing fluidized bed reactors, specifically a fluidized bed reactor with a circulating cup, or the STRONG fluidized bed reactor with a built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with the STRONG fluidized bed reactor with a built-in three-phase separator being preferred. When using a fluidized bed reactor with a circulating cup, a device with gas-liquid separation function needs to be installed between the first and second fluidized bed reaction zones, such as a high-pressure separator. Its main purpose is to separate the hydrogen and light hydrocarbon components from the heavy fraction in the reaction products of the first fluidized bed reactor.

[0045] Furthermore, in the above-mentioned combined treatment system for inferior hydrocarbon-containing raw materials, a gas-liquid separator may or may not be installed between the first and second fluidized bed reaction zones. When a gas-liquid separator is installed, the reaction products in the first fluidized bed reaction zone are separated to obtain gas-liquid flow and liquid flow, and the liquid flow enters the second fluidized bed reaction zone for processing.

[0046] Furthermore, in the aforementioned combined processing system for inferior hydrocarbon-containing feedstocks, the first separation system includes a first gas-liquid separator, a second gas-liquid separator, a third gas-liquid separator, and a first fractionation tower. The reaction products obtained from the second fluidized bed reaction zone first enter the first gas-liquid separator, where a first gaseous stream and a first liquid stream are separated. The first gaseous stream and, optionally, the gaseous stream separated from the first fluidized bed reaction zone, enter the second gas-liquid separator, where they are separated to obtain a second gaseous stream and a second liquid stream. The first liquid stream enters the third gas-liquid separator, where it is separated to obtain a third gaseous stream and a third liquid stream. The second and third gaseous streams are mixed and processed in a hydrogen recovery unit to obtain recycled hydrogen. The second and third liquid streams enter the first fractionation tower for separation to obtain hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil, and unconverted oil.

[0047] The combined processing technology and system for treating inferior hydrocarbon-containing raw materials provided by this invention have the following advantages:

[0048] 1. The combined processing technology and system for inferior hydrocarbon-containing raw materials provided by this invention organically combines hydrogenation and decarbonization processes, and assigns them suitable processing methods according to the characteristics of different materials, so as to achieve efficient processing and utilization of heavy oil, and obtain high-value light chemical raw materials (or clean oil products) and high-value-added low-sulfur petroleum coke; at the same time, the conversion rate of fluidized bed hydrogenation can be flexibly adjusted to ensure long-term operation of the unit.

[0049] 2. In the combined processing technology and system for inferior hydrocarbon-containing raw materials provided by the present invention, coking wax oil is returned to the fluidized bed reaction zone for further processing, making full use of existing equipment to process inferior coking wax oil and providing a new processing route for coking wax oil; at the same time, this process can achieve low circulation ratio operation in the coking process, reduce the yield of coking dry gas and petroleum coke, and increase the yield of liquid oil products.

[0050] 3. The inferior hydrocarbon-containing feedstock combined processing technology and system provided by this invention separates coking wax oil into light coking wax oil and heavy coking wax oil according to their property differences, and sends them to different fluidized bed reaction zones for processing, achieving a perfect match between component utilization and reaction zone operating conditions. This solves the problem of high investment costs in existing technologies where high nitrogen content (mainly difficult-to-remove basic nitrogen) and aromatics in coking wax oil necessitates hydrogenation under harsh operating conditions to obtain feedstocks that meet usage requirements (such as catalytic cracking). Simultaneously, it solves the problem in existing technologies where increasing the coking cycle ratio to reduce coking wax oil pressure leads to a significant decrease in liquid recovery, the generation of low-value dry gas, and reduced economic benefits.

[0051] 4. The combined treatment process and system for inferior hydrocarbon-containing feedstocks provided by this invention proposes mixing catalytic circulating oil and coking heavy wax oil, treating them through a filter, and then recycling them back to the first fluidized bed reaction zone. On the one hand, the presence of catalytic circulating oil helps reduce the viscosity of the coking heavy wax oil, enhances the filtration and separation effect, and facilitates the removal of coke dust contained in the coking heavy wax oil. On the other hand, the presence of catalytic circulating oil can also improve the system stability of the fluidized bed hydrogenation process, enabling long-term operation of the unit. The coke dust in the heavy wax oil can be discharged through the waste catalyst discharge system of the fluidized bed reactor.

[0052] 5. Compared to straight-run wax oil, coking wax oil has a higher nitrogen and aromatic content, with nitrogen compounds mainly consisting of difficult-to-remove basic nitrogen. If this fraction is discharged externally, a highly demanding hydrogenation process is required before it can be used as feedstock for catalytic cracking, resulting in relatively high investment costs. Increasing the coking recycle ratio to reduce the pressure of coking wax oil significantly reduces liquid yield, generating low-value dry gas and decreasing economic efficiency. This invention utilizes a fluidized bed hydrogenation unit, using its unconverted oil as coking feedstock to produce low-sulfur petroleum coke. The higher hydrogenation pressure is well-suited for removing aromatics and nitrogen compounds from the coking wax oil system.

[0053] 6. Compared with the existing fluidized bed addition and discharge process (where the conveying oil for the fluidized bed catalyst is the fluidized bed wax oil fraction), using coking wax oil rich in sulfur and olefins as the catalyst addition and discharge conveying oil can mitigate the problem of temperature instability in the fluidized bed system caused by the addition of conveying oil due to temperature drop by the exothermic reaction of the conveying oil itself.

[0054] 7. In the inferior hydrocarbon feedstock combination treatment process and system provided by the present invention, adding coking wax oil to the residue oil system can significantly improve the impurity removal effect, and the impurity content of the fluidized bed hydrogenated unconverted oil can be significantly reduced, which is beneficial to improving coking feed and ensuring the production of high-quality petroleum coke products. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the combined processing technology for inferior hydrocarbon-containing raw materials according to the present invention. Detailed Implementation

[0056] The technical features of the present invention are further described below with reference to specific examples and accompanying drawings, but these embodiments are not intended to limit the present invention.

[0057] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0058] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0059] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0060] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0061] This invention provides a combined processing technology for inferior hydrocarbon-containing raw materials, such as... Figure 1As shown, the specific process of the treatment is as follows: Hydrocarbon-containing feedstock 1, recycled hydrogen 32, and fresh hydrogen 39 enter the first fluidized bed reaction zone 2 for reaction. The reaction effluent is separated by the fluidized bed gas-liquid separator 3 to obtain gas phase stream 4 and liquid phase stream 5. The liquid phase stream 5, recycled hydrogen 32, and fresh hydrogen 39 enter the second fluidized bed reaction zone 6 for reaction. The reaction products first enter the first gas-liquid separator 7, separating to obtain the first gas phase stream 8 and the first liquid phase stream 13. The first gas phase stream 8 and the gas phase stream separated in the first fluidized bed reaction zone... Stream 4 enters the second gas-liquid separator 9, and after separation, it yields the second gas phase stream 10 and the second liquid phase stream 12; the first liquid phase stream 13 enters the third gas-liquid separator 14, and after separation, it yields the third gas phase stream 15 and the third liquid phase stream 16. The second gas phase stream 10 and the third gas phase stream 15 are mixed and enter the hydrogen recovery unit 11 for processing to obtain recycled hydrogen 32; the second liquid phase stream 12 and the third liquid phase stream 16 enter the first fractionation tower 17, and after separation, they yield hydrotreated naphtha 18, hydrotreated diesel 19, hydrotreated wax oil 20, and unconverted oil 21. The unconverted oil 21 obtained enters the coking reaction zone 22, and after the reaction, petroleum coke 30 is obtained. The coking reaction products are separated by the second fractionation system 23 to obtain coking gas 24, coking naphtha 25, coking diesel 26, coking light wax oil 27, coking heavy wax oil 28, and coking cycle oil 29. Among them, coking light wax oil 27 is partially or completely recycled back to the second fluidized bed reaction zone 6, and coking heavy wax oil 28 is partially or completely recycled back to the first fluidized bed reaction zone 1 via pipeline. The pipeline is equipped with a filtration system 31. Coking cycle oil 29 can be recycled back to the coking reaction zone 22 for further processing. Hydrogenated wax oil 20 can enter the catalytic cracking reaction zone 33 for reaction, and after the reaction, cracked gas 34, catalytic gasoline 35, catalytic diesel 36, catalytic cycle oil 37, and catalytic slurry 38 are obtained. Catalytic cycle oil 37 can be mixed with coking heavy wax oil and filtered and separated by the filtration system 31 before being returned to the first fluidized bed reaction zone 2 for further processing. The catalytic slurry 38 can be processed in the first fluidized bed reaction zone 2 and / or the coking reaction zone 22. Preferably, a portion is processed in the first fluidized bed reaction zone 2, and the remainder is processed in the coking reaction zone 22.

[0062] The properties of the residual oil feedstock used in the embodiments and comparative examples of this invention are shown in Table 1.

[0063] Table 1 Properties of Residue Oil Feedstock

[0064] project heavy oil <![CDATA[Density (20 °C), g / cm 3 > 1.011 Residual carbon, wt% 21.4 Sulfur content, wt% 5.13 Nitrogen content, wt% 0.38 Metal (Ni+V), mg / kg 221.0 Asphalt, wt% 13.14

[0065] Example 1

[0066] Example 1 uses Figure 1The process flow is shown below. All coking heavy wax oil is recycled back to the first fluidized bed reaction zone, and a backwash filter is installed on the return pipeline. All coking light wax oil is returned to the second fluidized bed reaction zone. All catalytic heavy circulating oil and catalytic slurry are returned to the first fluidized bed reaction zone.

[0067] The first fluidized bed reaction zone was filled with FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with a reaction pressure of 18 MPa, a hydrogen-to-oil volume ratio of 400, and a volume hourly space velocity of 0.36 h⁻¹. -1 The average reaction temperature in the reaction zone is 420℃.

[0068] The second fluidized bed reaction zone was filled with the FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with a reaction pressure of 17.5 MPa, a hydrogen-to-oil volume ratio of 400, and a volume hourly space velocity of 0.36 h⁻¹. -1 The average reaction temperature in the reaction zone is 425℃.

[0069] The cut-off temperature for hydrotreated naphtha and hydrotreated diesel is 210℃, for hydrotreated diesel and hydrotreated wax oil it is 350℃, and for hydrotreated wax oil and unconverted oil it is 520℃. The coking unit uses a conventional process with one heater, two coking towers, and one fractionation tower. The heater outlet temperature is 490℃, the coking tower pressure is 0.18 MPa, and the recycle ratio is 0.1. The cut-off temperature for coked naphtha and coking diesel is 210℃, for coking diesel and coking light wax oil it is 350℃, for coking light wax oil and coking heavy wax oil it is 420℃, and for coking heavy wax oil and coking circulating oil it is 500℃.

[0070] The catalytic cracking unit uses the DFC-1 catalyst (produced by Sinopec Changling Catalyst Co., Ltd.), which is commonly used in existing industrial plants. The reaction temperature is 495℃, the reaction pressure is 0.2MPa, and the reaction time is 3.0s.

[0071] Example 2

[0072] The process flow for Example 2 is the same as that for Example 1.

[0073] The first fluidized bed reaction zone was filled with FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with a reaction pressure of 15 MPa, a hydrogen-to-oil volume ratio of 600, and a volume hourly space velocity of 0.28 h⁻¹. -1 The average reaction temperature in the reaction zone is 415℃.

[0074] The second fluidized bed reaction zone was filled with the FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., with a reaction pressure of 17.5 MPa, a hydrogen-to-oil volume ratio of 600, and a volume hourly space velocity of 0.28 h⁻¹. -1 The average reaction temperature in the reaction zone is 419℃.

[0075] Example 3

[0076] The process flow of Example 3 is basically the same as that of Example 1, the main difference being the external discharge of catalytic circulating oil and catalytic oil slurry, the rest are the same.

[0077] Comparative Example 1

[0078] The difference between the process flow of Comparative Example 1 and the process flow of Example 1 is as follows: Figure 1 In the coking reaction zone 22, the coking wax oil in the target product is not separated into coking light wax oil 27 and coking heavy wax oil 28. The coking wax oil is directly fed into the catalytic cracking reaction zone 33 for processing without separation, while the catalytic circulating oil and catalytic slurry are discharged.

[0079] project Example 1 Example 2 Example 3 Comparative Example 1 Product distribution, wt% dry air 4.33 4.37 4.28 4.63 Liquefied gas 9.31 9.23 9.03 9.13 naphtha 34.39 34.38 33.36 32.74 diesel fuel 41.99 42.10 40.92 40.11 petroleum coke 7.51 7.45 7.44 7.78 Burnt 2.12 2.11 2.04 2.30 Catalytic heavy oil 2.73 3.17 Total liquid yield 76.38 76.48 74.28 72.85

Claims

1. A combined processing technology for inferior hydrocarbon-containing raw materials, the combined processing technology comprising the following steps: (1) Hydrocarbon feedstock and hydrogen are sequentially fed into the first and second fluidized bed reaction zones set in series for reaction. The reaction products are separated to obtain gas, hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil and unconverted oil. The cutting point of hydrotreated wax oil and unconverted oil is 450-550℃. Hydrotreated wax oil is fed into the catalytic cracking reaction zone for reaction. After the reaction, cracked gas, catalytic gasoline, catalytic diesel, catalytic cycle oil and catalytic slurry are obtained. Catalytic cycle oil and coking heavy wax oil are mixed and filtered and separated before being returned to the first fluidized bed reaction zone for processing. Catalytic slurry is fed into the first fluidized bed reaction zone for processing. (2) The unconverted oil obtained in step (1) enters the coking reaction zone, reacts, and is separated to obtain petroleum coke, coking gas, coking naphtha, coking diesel, coking light wax oil, coking heavy wax oil, and coking cycle oil; among which, All coking light wax oil is recycled back to the second boiling bed reaction zone, and all coking heavy wax oil is recycled back to the first boiling bed reaction zone; the cutting point temperature of coking light wax oil and coking heavy wax oil is 400-450℃, and the cutting point temperature of coking heavy wax oil and coking circulating oil is 490℃-540℃.

2. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, A gas-liquid separator may or may not be installed between the first and second fluidized bed reaction zones. When a gas-liquid separator is installed, the reaction products in the first fluidized bed reaction zone are separated into a gas-liquid stream and a liquid stream. The liquid stream enters the second fluidized bed reaction zone for processing.

3. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The catalytic oil slurry is partially processed in the first boiling bed reaction zone, while the remaining portion is processed in the coking reaction zone.

4. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The coking circulating oil obtained in step (2) is recycled back to the coking reaction zone for processing.

5. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The hydrocarbon-containing raw material mentioned in step (1) is selected from one or more of atmospheric residue, vacuum residue, and heavy oil from oil fields.

6. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 5, wherein, The hydrocarbon-containing raw materials mentioned in step (1) are also blended with one or more of the following: catalytic oil slurry, vacuum wax oil, and furfural extract oil.

7. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The separation process of the reaction products in the second fluidized bed reaction zone is as follows: The reaction products obtained in the second fluidized bed reaction zone first enter the first gas-liquid separator, and are separated into a first gas phase stream and a first liquid phase stream; the first gas phase stream and the gas phase stream obtained from the first fluidized bed reaction zone (optionally) enter the second gas-liquid separator, and are separated into a second gas phase stream and a second liquid phase stream; the first liquid phase stream enters the third gas-liquid separator, and is separated into a third gas phase stream and a third liquid phase stream; the second gas phase stream and the third gas phase stream are mixed and then processed in the hydrogen recovery unit to obtain recycled hydrogen; The second and third liquid phase streams are separated in the first fractionation tower to obtain hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil, and unconverted oil.

8. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The operating conditions for the first fluidized bed reaction zone are as follows: reaction temperature 350–450℃, reaction pressure 10.0–20.0 MPa, hydrogen-to-oil volume ratio 300–1000, and liquid hourly space velocity 0.1–5.0 h⁻¹. -1 .

9. The combined treatment process for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The operating conditions for the first fluidized bed reaction zone are: reaction temperature 380–430℃, reaction pressure 15.0–18.0 MPa, hydrogen-to-oil volume ratio 400–600, and liquid hourly space velocity 0.2–0.5 h⁻¹. -1 .

10. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The operating conditions for the second fluidized bed reaction zone are as follows: reaction temperature 350–450℃, reaction pressure 10.0–20.0 MPa, hydrogen-to-oil volume ratio 300–1000, and liquid hourly space velocity 0.1–5.0 h⁻¹. -1 .

11. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The operating conditions for the second fluidized bed reaction zone are as follows: reaction temperature 380–430℃, reaction pressure 15.0–18.0 MPa, hydrogen-to-oil volume ratio 400–600, and liquid hourly space velocity 0.2–0.5 h⁻¹. -1 .

12. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The cutting point for hydrogenated wax oil and unconverted oil is 500℃~540℃.

13. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The coking reaction zone in step (2) includes at least one heating furnace, two coking towers and one fractionation tower; the outlet temperature of the heating furnace is 480-520℃, the pressure of the coking tower is 0.1MPa-0.5MPa, and the circulation ratio is 0.05-1.

0.

14. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The coking reaction zone in step (2) includes at least one heating furnace, two coking towers and one fractionation tower; the outlet temperature of the heating furnace is 490℃~510℃; the pressure of the coking tower is 0.15~0.25MPa; and the circulation ratio is 0.1~0.

3.

15. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The cutting point temperature of coking light wax oil and coking heavy wax oil in step (2) is 410℃~430℃; the cutting point temperature of coking heavy wax oil and coking circulating oil is 500℃~520℃.

16. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, When the coking heavy wax oil is circulated back to the first boiling bed reaction zone, a coking powder filter is installed on the return pipeline, and the coking powder content in the purified coking wax oil is controlled to be no more than 0.01 wt%.

17. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, Coking light wax oil and / or coking heavy wax oil are used as transport oils for the fluidized bed hydrogenation catalyst in the first fluidized bed reaction zone and the second fluidized bed reaction zone, and are returned to the corresponding fluidized bed reactor in a manner that carries the fluidized bed catalyst.

18. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The reaction conditions in the catalytic cracking reaction zone are as follows: reaction temperature is 480–550℃, the mass ratio of steam to feed is 0.05:1–1:1, the reaction pressure is 0.10–1.0 MPa, and the contact time with the catalyst is 0.1–15.0 seconds.

19. The combined processing technology for inferior hydrocarbon-containing raw materials according to claim 1, wherein, The reaction conditions in the catalytic cracking reaction zone are as follows: reaction temperature is 490–510℃; the mass ratio of steam to feed is 0.05:1–0.5:1; the reaction pressure is 0.10–0.5 MPa; and the contact time with the catalyst is 0.5–5.0 seconds.

20. A combined processing system for inferior hydrocarbon feedstocks that implements the combined processing technology for inferior hydrocarbon feedstocks according to any one of claims 1-19, wherein the combined processing system comprises a fluidized bed reaction zone, a coking reaction zone, and a catalytic cracking reaction zone; The fluidized bed reaction zone includes a first fluidized bed reaction zone and a second fluidized bed reaction zone arranged in series. It is used to receive hydrocarbon-containing raw materials and hydrogen gas, and the hydrocarbon-containing raw materials and hydrogen gas undergo a hydrogenation reaction after contact. The first separation system includes a gas-liquid separation unit and a first fractionation unit, which is used to receive and separate the reaction products from the fluidized bed reaction zone, and obtain gas, hydrotreated naphtha, hydrotreated diesel, hydrotreated wax oil and unconverted oil after separation. The coking reaction zone is used to receive unconverted oil from the separation system. The unconverted oil undergoes a coking reaction, and the resulting petroleum coke, coking gas, and liquid fraction are obtained. The second separation system is used to receive and separate the liquid phase fraction from the coking reaction zone, and obtain coking naphtha, coking diesel, coking light wax oil, coking heavy wax oil and coking circulating oil after separation; the coking light wax oil is connected to the second fluidized bed reaction zone through pipeline, and the coking heavy wax oil is connected to the first fluidized bed reaction zone through pipeline. The catalytic cracking reaction zone receives hydrotreated wax oil from the first separation system. After undergoing catalytic cracking, the hydrotreated wax oil produces cracked gas, catalytic gasoline, catalytic diesel, catalytic cycle oil, and catalytic slurry. The catalytic cycle oil is connected to the coking heavy wax oil pipeline via a pipeline and to the first fluidized bed reaction zone via a pipeline. A separation device is installed on the pipeline. The catalytic slurry is connected to the first fluidized bed reaction zone via a pipeline.

21. The combined processing system for inferior hydrocarbon-containing raw materials according to claim 20, wherein, The separation device is a filter, wherein the filter is at least one of a backwash filter and a ceramic membrane filter.

22. The combined processing system for inferior hydrocarbon-containing raw materials according to claim 20, wherein, Part of the catalytic slurry is connected to the first fluidized bed reaction zone via pipeline, and the remaining part of the catalytic slurry is connected to the coking reaction zone via pipeline.

Images