A method and system for producing high value products with high utilization of crude oil

Abstract

The present application relates to a method and system for producing high-value products with high utilization of crude oil, which comprises: (1) subjecting crude oil to distillation cutting to obtain light crude oil fraction and heavy crude oil fraction; (2) subjecting the heavy crude oil fraction to extraction separation to obtain extracted oil of the heavy crude oil fraction and raffinate oil of the heavy crude oil fraction; (3) contacting a catalytic cracking raw material with a catalyst in a catalytic cracking reactor to perform a catalytic cracking reaction, and separating oil and gas to obtain cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil; the catalytic cracking raw material comprises the light crude oil fraction, the extracted oil of the heavy crude oil fraction and difficult-to-convert components. The present application adopts a method combining crude oil component separation and catalytic cracking reaction, and can convert intermediate-based crude oil or poor-quality naphthenic-based crude oil into high-value products, with a yield of high-value products in the whole process close to 65% or more.

Description

Technical Field

[0001] This invention relates to the field of petrochemicals, and more specifically to a method and system for producing high-value products with high crude oil utilization. Background Technology

[0002] With overcapacity in oil refining and a slowing demand for refined oil products, ethylene, propylene, and BTX (benzene-toluene-xylene) are key basic organic synthesis raw materials in huge demand, while demand for chemical products remains strong. Existing technologies for producing propylene and BTX from petroleum are developed based on traditional oil refining processes primarily focused on oil production. These processes suffer from long production lines, low yields of high-value products, and insignificant economic benefits. The key to solving these problems is to develop core technologies that enable the targeted conversion of crude oil hydrocarbon molecules into high-value products. Therefore, in recent years, international petrochemical companies, represented by ExxonMobil and Saudi Aramco, have begun to innovate traditional refining processes. These companies have revolutionized traditional oil refining processes, elevating integrated refining and chemical production to a new level of directly producing high-value products from crude oil.

[0003] ExxonMobil is a pioneer in the research and development of crude oil steam cracking to olefins, and was the first company to build an industrial-scale demonstration plant. It has also applied for a series of patents, such as CN200580016314.X. The company's process for directly producing high-value products from crude oil involves directly feeding crude oil into a steam cracker, where it undergoes flash evaporation to separate light and heavy components. The light components (gaseous components) are then further cracked in the steam cracker, while the heavy components (liquid components) are used as feedstock for refineries. If the selected crude oil is sufficiently light and has no fractions above 593°C (i.e., no bottom residue), it can be produced without relying on a refinery. The company's first industrial-scale plant used ultralight paraffinic Tapis crude oil with an API gravity of 42.7 as feedstock.

[0004] Saudi Aramco's technological strength lies in its use of crude oil pretreatment and hydrotreating technologies to minimize the impact of non-volatile components in crude oil on steam cracking. Simultaneously, a vapor-liquid (steam and liquid) separation device is installed between the convection and radiant sections of the steam cracker to remove non-volatile liquids (liquid phases), ensuring that the material entering the radiant section is free of liquid entrainment, thus preventing coking in the furnace tubes. The heavier components are then fed into the catalytic cracking unit. This can be described as an integrated process for producing olefins and aromatics from crude oil, combining hydrotreating, steam cracking, and catalytic cracking.

[0005] Due to the presence of heavy components in crude oil that are difficult to vaporize, existing technologies for directly producing high-value products from crude oil are only suitable for low-sulfur, paraffin-based crude oils with an API gravity of around 45. Other crude oil-to-chemicals (CTC) technologies vary among companies depending on the processing of heavy components, but all employ fractionation. They combine processes based on the properties of different distillate fractions to produce high-value products from crude oil. Compared to traditional refining processes, this only changes the distillate range and quantity and integrates existing processing techniques, failing to achieve a fundamental technological revolution. Furthermore, these existing combined technologies are more suitable for light crude oils or paraffin-based crude oils; when using inferior crude oils such as heavy crude oils or intermediate-based crude oils as feedstock, the yield of high-value products is low. Finding a method or system to convert inferior crude oil into high-value products with high yield is a pressing technical problem that needs to be solved. Summary of the Invention

[0006] This invention provides a method and system for producing high-value products with high crude oil utilization. The purpose is to enable inferior oil to be effectively converted into high-value products. The process is not only short, but also has a high yield of high-value products and a low yield of coke, which can significantly reduce carbon emissions in the process.

[0007] In a first aspect, the present invention relates to a method for producing high-value products with high crude oil utilization, the method comprising the following steps:

[0008] (1) Distill crude oil to obtain light crude oil fraction and heavy crude oil fraction; wherein the cutting point of the light crude oil fraction and the heavy crude oil fraction is 240-350℃;

[0009] (2) Extract and separate the crude oil heavy fraction to obtain crude oil extract and crude oil residue.

[0010] (3) In a catalytic cracking reactor, the catalytic cracking feedstock is brought into contact with the catalyst to carry out a catalytic cracking reaction, and cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel and cracked heavy oil are obtained by oil-gas separation; the catalytic cracking feedstock includes the light fraction of crude oil, the extracted oil of the heavy fraction of crude oil and difficult-to-convert components; wherein, the difficult-to-convert components include light hydrocarbons and / or light distillate oil.

[0011] Secondly, the present invention relates to a system for producing high-value products with high crude oil utilization, the system comprising a distillation unit, an extraction and separation unit, and a catalytic cracking unit;

[0012] The distillation unit is equipped with a crude oil inlet, a crude oil light fraction outlet pipeline, and a crude oil heavy fraction outlet pipeline;

[0013] The crude oil heavy distillate outlet pipeline is connected to the material inlet of the extraction and separation unit. The extraction and separation unit is also provided with an extraction solvent inlet, an extracted oil outlet of the crude oil heavy distillate, and a raffinate oil outlet of the crude oil heavy distillate.

[0014] The catalytic cracking unit is equipped with a catalytic cracking feedstock inlet, a cracking gas outlet, a cracking light gasoline outlet, a cracking heavy gasoline outlet, a cracking diesel outlet, and a cracking heavy oil outlet;

[0015] The catalytic cracking feedstock inlet of the catalytic cracking unit is connected to the extracted oil outlet of the heavy crude oil fraction and the outlet pipeline of the light crude oil fraction, respectively.

[0016] The catalytic cracking unit is also provided with an inlet for difficult-to-convert components.

[0017] Beneficial effects:

[0018] 1) It has strong adaptability to crude oil. By using a combination of crude oil component separation and catalytic cracking reaction, intermediate base crude oil or lower quality naphthenic crude oil can be converted into high-value products.

[0019] 2) High crude oil utilization rate: Since low-quality crude oil contains more difficult-to-crack components such as polycyclic aromatic hydrocarbons, gums and asphaltenes, which are mainly distributed in the heavy fraction of crude oil, separating polycyclic aromatic hydrocarbons, gums and asphaltenes in the heavy fraction of crude oil as raffinate oil reduces the competitive adsorption on the active sites of the catalyst, which helps to improve the selectivity of the extracted oil with better cracking performance to generate high-value products, thus achieving efficient utilization of crude oil.

[0020] 3) High yield of high-value products; the raffinate oil from the heavy fraction of crude oil, which is rich in polycyclic aromatic hydrocarbons or asphaltene, can be used as a feedstock for needle coke or road asphalt depending on its properties; the extracted oil is used as a feedstock for catalytic cracking to be converted into low-carbon olefins and aromatics, and the yield of high-value products in the whole process is close to 65% or more.

[0021] 4) High online rate of the unit; inferior crude oil has high content of residual carbon, high metal and high asphaltene. After component separation, the quality of catalytic cracking feedstock is greatly improved. Not only is the yield of target product high, but the operating cycle is extended and the online rate is improved, thereby effectively improving economic benefits.

[0022] Using the method or system of this application, high-value products such as low-carbon olefins and light aromatics can be directly and efficiently produced from low-quality crude oil. This not only produces high-value chemical raw materials and promotes the deep integration of the oil refining and petrochemical industries, but also effectively addresses the challenges brought about by the scarcity of oil resources and safeguards national energy security. Attached Figure Description

[0023] Figure 1This is a schematic diagram of a specific embodiment of a system for producing high-value products with high crude oil utilization according to the present invention;

[0024] Explanation of reference numerals in the attached figures:

[0025] Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0027] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0028] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0029] Any specific numerical values ​​disclosed herein (including the endpoints of numerical ranges) are not limited to their exact values, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Furthermore, with respect to the disclosed numerical ranges, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values ​​themselves; these new numerical ranges should also be considered as specifically disclosed herein.

[0030] Unless otherwise stated, the terms used herein have the same meaning as commonly understood by those skilled in the art, and if a term is defined herein and its definition differs from the common understanding in the art, the definition herein shall prevail.

[0031] In this application, the terms "upstream" and "downstream" refer to the direction of reaction material flow. For example, when the reaction material flows from bottom to top, "upstream" refers to the position located at the bottom, while "downstream" refers to the position located at the top.

[0032] In a first aspect, the present invention relates to a method for producing high-value products with high crude oil utilization, the method comprising the following steps:

[0033] (1) Distill crude oil to obtain light crude oil fraction and heavy crude oil fraction; wherein the cutting point of the light crude oil fraction and the heavy crude oil fraction is 240-350℃;

[0034] (2) Extract and separate the crude oil heavy fraction to obtain crude oil extract and crude oil residue.

[0035] (3) In a catalytic cracking reactor, the catalytic cracking feedstock is brought into contact with the catalyst to carry out a catalytic cracking reaction, and cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel and cracked heavy oil are obtained by oil-gas separation; the catalytic cracking feedstock includes the light fraction of crude oil, the extracted oil of the heavy fraction of crude oil and difficult-to-convert components; wherein, the difficult-to-convert components include light hydrocarbons and / or light distillate oil.

[0036] It should be noted that in step (1), crude oil is distilled and separated into light and heavy fractions based on the difference in boiling points; in step (2), the heavy fraction is extracted to obtain saturated hydrocarbon-rich extract oil and aromatic hydrocarbon-rich residue oil; in step (3), the catalytic cracking feedstock undergoes a catalytic cracking reaction under high temperature and catalyst conditions, and high-value products such as low-carbon olefins and light aromatics can be obtained through oil-gas separation and other steps. According to this application, the method for separating the reaction products to obtain cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel, and cracked heavy oil can be a conventional method in the art or a method well known to those skilled in the art.

[0037] The method of this application first cuts crude oil into light and heavy sections, and then separates the raffinate oil rich in polycyclic aromatic hydrocarbons, gums and asphaltenes through extraction and separation. This reduces the competitive adsorption on the active sites of the catalyst, which helps to improve the selectivity of the extracted oil with better cracking performance to generate high-value products, thus achieving efficient utilization of crude oil. In addition, the catalytic cracking feedstock also introduces the above-mentioned difficult-to-convert components, which effectively improves the yield of high-value products.

[0038] According to a specific embodiment of the method described in the first aspect of the present invention, the pyrolysis gas from step (3) is subjected to gas separation to obtain ethylene, propylene, C4 components and other products;

[0039] The light hydrocarbons of the difficult-to-convert components include the C4 components;

[0040] The light distillate oil of the difficult-to-convert components includes light distillate oil with a final boiling point of less than 280-350°C, and the light distillate oil of the difficult-to-convert components preferably includes the cracked light gasoline obtained from step (3).

[0041] It should be noted that, as a preferred embodiment, the difficult-to-convert components used as part of the catalytic cracking feedstock in step (3) include C4 components obtained from gas separation and cracked light gasoline obtained from oil-gas separation. In this case, the composition of the catalytic cracking feedstock can be C4 components, cracked light gasoline, crude oil light fraction, and crude oil heavy fraction extract. In the process described in this application, this type of catalytic cracking feedstock is beneficial for further increasing the yield of the target product, i.e., the high-value product. In addition, the method for gas separation of the cracked gas to obtain ethylene, propylene, C4 components, and other products can be carried out using conventional methods in the art or methods well known to those skilled in the art.

[0042] According to a preferred embodiment of the method described in the first aspect of the present invention, the method further includes the following steps:

[0043] The cracked diesel from step (3) is subjected to hydrotreating to obtain hydrocracked diesel;

[0044] The catalytic cracking feedstock in step (3) also includes the hydrocracking diesel.

[0045] It should be noted that, in this preferred embodiment, the cracked diesel obtained from step (3) undergoes a hydrogenation reaction under the action of hydrogen and a hydrotreating catalyst. The resulting hydrocracked diesel can be used as a component for producing high-octane gasoline or aromatics, or it can be used as a catalytic cracking feedstock to undergo the catalytic cracking reaction in step (3) together with the extract oil from the light and heavy fractions of crude oil. Using hydrocracked diesel as part of the catalytic cracking feedstock, and subjecting it to catalytic cracking reactions together with other feedstocks, is beneficial for further increasing the yield of the target product, i.e., the high-value product.

[0046] It should be noted that the cracked diesel oil undergoes a hydrotreating reaction in the presence of hydrogen, in contact with a hydrotreating catalyst. The hydrotreating reaction conditions can be: hydrogen partial pressure 4-25 MPa, reaction temperature 330-460℃, and volume hourly space velocity 0.1-10 h⁻¹. -1 Hydrogen-to-oil volume ratio 300-2000 Nm 3 / m 3 Preferably, the hydrogen partial pressure is 7-15 MPa, the reaction temperature is 350-400 °C, and the volume hourly space velocity is 1-6 h⁻¹. -1 Hydrogen-to-oil volume ratio 500-1400 Nm 3 / m 3 .

[0047] It should be noted that, in one embodiment, the active metal component of the hydrogenation catalyst is selected from Group VIB metals and / or Group VIII non-precious metals, and the support is selected from one or more of alumina, silica, and amorphous silica-alumina. The Group VIB metal is molybdenum and / or tungsten, and the Group VIII non-precious metal is nickel and / or cobalt. Preferably, the active metal component is a combination of one or more of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum, or cobalt-molybdenum; preferably, in the hydrogenation catalyst, the content of nickel and / or cobalt, based on the total weight of the hydrogenation catalyst, is 1-25% by weight (calculated as oxides), and the content of molybdenum and / or tungsten, based on oxides, is 3-35% by weight.

[0048] According to a preferred embodiment of the method described in the first aspect of the present invention, the C4 component, the light crude oil fraction, the cracked light gasoline, the extract oil from the heavy crude oil fraction, and the hydrocracked diesel are introduced into the catalytic cracking reactor at independent locations; preferably, inlets for the C4 component, the light crude oil fraction, the cracked light gasoline, the extract oil from the heavy crude oil fraction, and the hydrocracked diesel are sequentially arranged from upstream to downstream of the catalytic cracking reactor; and / or,

[0049] The weight percentages of the C4 component, which is the difficult-to-convert component, and the cracked light gasoline in the catalytic cracking feedstock are each 5-20%;

[0050] The hydrocracking diesel fuel accounts for 5-30% of the weight of the catalytic cracking feedstock.

[0051] It should be noted that, in this embodiment, the composition of the catalytic cracking feedstock can be C4 components, light crude oil fractions, cracked light gasoline, extract oil from heavy crude oil fractions, and hydrocracked diesel. In this case, the catalytic cracking feedstocks are fed in the aforementioned feed sequence, or in other words, the feed inlets of the aforementioned catalytic cracking feedstocks are arranged sequentially from upstream to downstream. This catalytic cracking reaction further improves the yield of the target product, i.e., the high-value product. As a further preferred embodiment, while controlling the feed sequence or position as described above, controlling the weight percentages of C4 components and cracked light gasoline in the catalytic cracking feedstock, and / or the weight percentage of hydrocracked diesel in the catalytic cracking feedstock as described above, can further improve the yield of the target product, i.e., the high-value product.

[0052] In another preferred embodiment of the method according to the first aspect of the present invention, the catalytic cracking feedstock in step (3) further includes the cracked diesel oil;

[0053] The C4 component, the light crude oil fraction, the cracked light gasoline, the extracted oil from the heavy crude oil fraction, and the cracked diesel are introduced into the catalytic cracking reactor at independent locations; preferably, inlets for the C4 component, the light crude oil fraction, the cracked light gasoline, the extracted oil from the heavy crude oil fraction, and the cracked diesel are sequentially located from upstream to downstream of the catalytic cracking reactor; and / or,

[0054] The weight percentages of the C4 component, which is the difficult-to-convert component, and the cracked light gasoline in the catalytic cracking feedstock are each 5-20%;

[0055] The cracked diesel fuel accounts for 5-30% of the weight of the catalytic cracking feedstock.

[0056] It should be noted that, in this preferred embodiment, the composition of the catalytic cracking feedstock can be C4 components, light crude oil fractions, cracked light gasoline, extract oil from heavy crude oil fractions, and cracked diesel. In this case, the catalytic cracking feedstocks are fed in the aforementioned feed sequence, or in other words, the feed inlets of the aforementioned catalytic cracking feedstocks are arranged sequentially from upstream to downstream. This catalytic cracking reaction further improves the yield of the target product, i.e., the high-value product. As a further preferred embodiment, while controlling the feed sequence or position as described above, controlling the weight percentages of C4 components and cracked light gasoline in the catalytic cracking feedstock, and / or the weight percentage of cracked diesel in the catalytic cracking feedstock as described above, can further improve the yield of the target product, i.e., the high-value product.

[0057] According to a specific embodiment of the method described in the first aspect of the present invention, in step (1),

[0058] The crude oil is selected from one or more of the following: paraffinic crude oil, paraffinic-intermediate crude oil, intermediate-paraffinic crude oil, and intermediate-based crude oil; and / or,

[0059] The crude oil meets at least one of the following criteria:

[0060] The density at 20℃ is 835-935 kg / m³. 3 The API gravity is greater than 28, the UOP K value is not less than 11.5, and the metal content is greater than 30 mg / kg. It can meet one, two, three, or four of the above indicators.

[0061] It should be noted that the method of the present invention has strong raw material adaptability, high yield of high-value products, and a short process flow, while significantly reducing carbon emissions. Either the first and second key components of the paraffinic crude oil are paraffinic; the first key component of the paraffinic-intermediate crude oil is paraffinic and the second key component is intermediate; the first key component of the intermediate-paraffinic crude oil is intermediate and the second key component is paraffinic; either the first and second key components of the intermediate-based crude oil are intermediate. The cut-off points for the light and heavy fractions of the crude oil can also be 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, etc.

[0062] The method of this application can not only produce high-value products from ordinary crude oil with high yield, but also produce high-value products from inferior crude oils such as intermediate base crude oil with high yield, thus developing a better conversion process for inferior crude oil.

[0063] According to a specific embodiment of the method described in the first aspect of the present invention, in step (2),

[0064] The yield of the extracted oil from the heavy fraction of the crude oil is greater than 50% by weight, preferably greater than 65% by weight; and / or,

[0065] The extracted oil from the heavy crude oil fraction contains a saturated fraction content greater than 45% by weight, preferably greater than 50% by weight; and / or,

[0066] The heavy metal removal rate of the extracted oil from the crude oil heavy fraction is greater than 80% by weight, preferably greater than 90% by weight; and / or,

[0067] The asphaltene removal rate of the extracted oil from the heavy crude oil fraction is greater than 90%, preferably greater than 95%.

[0068] It should be noted that, by controlling the yield, saturated fraction content, metal removal rate and asphalt removal rate of the crude oil heavy fraction as described above, the crude oil heavy fraction extract can be carried out together with other catalytic cracking feedstocks such as crude oil light fraction in step (3) catalytic cracking reaction, which is conducive to further improving the yield of high-value products.

[0069] According to a specific embodiment of the method described in the first aspect of the present invention, in step (3), the light hydrocarbon of the difficult-to-convert component includes gaseous hydrocarbons rich in C4 fractions produced by other devices or processes, and the light hydrocarbon of the difficult-to-convert component preferably includes C4 fractions produced by other devices or processes.

[0070] The light distillate oil containing the difficult-to-convert components is selected from one or more of the following oil products:

[0071] Other primary processing units produce straight-run naphtha, straight-run kerosene, and straight-run diesel, as well as secondary processing products such as topping oil, residue oil, hydrocracking light naphtha, pentane oil, coking gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrotreated gasoline, and hydrotreated diesel.

[0072] It should be noted that, in one embodiment, the light hydrocarbons in the difficult-to-convert component are C4 components. These C4 components refer to low-molecular-weight hydrocarbons existing in gaseous form at room temperature and pressure, with C4 fractions as the main component. They include alkanes, alkenes, and alkynes with four carbon atoms in their molecules. This includes gaseous hydrocarbon products rich in C4 fractions produced by the process of this invention, and may also include gaseous hydrocarbons rich in C4 fractions produced by other processes or equipment, with the C4 fraction produced by the process of this invention being preferred. The C4 hydrocarbons are preferably C4 fractions rich in olefins, wherein the content of C4 olefins is greater than 50% by weight, preferably greater than 60% by weight, and most preferably greater than 70% by weight.

[0073] In one embodiment, the light distillate oil in the difficult-to-convert component is a light distillate oil with a final boiling point of less than 280-350℃, including light distillate oil with a final boiling point of less than 280-350℃ produced by the process of the present invention, and may also include one or more mixtures of primary processed straight-run naphtha, straight-run kerosene, and straight-run diesel; and one or more mixtures of secondary processed topping oil, residue oil, hydrocracked light naphtha, pentane oil, coking gasoline, Fischer-Tropsch synthetic oil, catalytic cracked light gasoline, hydrotreated gasoline, and hydrotreated diesel.

[0074] According to a specific embodiment of the method described in the first aspect of the present invention, in step (2),

[0075] The extraction separation is supercritical fluid extraction separation, and the extraction solvent used is selected from low-carbon alkanes, specifically one or a mixture of several of the following: ethane, propane, n-butane, isobutane, n-pentane, isopentane, hexane, heptane, and octane; and / or,

[0076] The extraction and separation conditions include: a temperature of 50-100℃, a pressure of 6-20 MPa, and a weight ratio of the extraction solvent to the crude oil heavy fraction of (2-5):1.

[0077] It should be noted that by controlling the extraction and separation conditions in step (2) as described above, the extracted oil from the heavy fraction of crude oil and other components such as the light fraction of crude oil can be used as raw materials for catalytic cracking in step (3). This allows the raw materials to undergo catalytic cracking reactions more effectively, thereby increasing the yield of high-value products.

[0078] According to a specific embodiment of the method described in the first aspect of the present invention, in step (3), the conditions for the catalytic cracking reaction include:

[0079] The catalytic cracking feedstock is mixed with water vapor and then fed into the reaction. The reaction temperature is 510-650℃ and the reaction time is 1-20 seconds. The weight ratio of the catalyst to the catalytic cracking feedstock is (3-50):1, and the weight ratio of the water vapor to the catalytic cracking feedstock is (0.03-0.8):1.

[0080] In step (3), the conditions for the catalytic cracking reaction preferably include:

[0081] The catalytic cracking feedstock is mixed with water vapor and then fed into the reaction. The reaction temperature is 550-620℃ and the reaction time is 2-10 seconds. The weight ratio of the catalyst to the catalytic cracking feedstock is (10-30):1, and the weight ratio of the water vapor to the catalytic cracking feedstock is (0.10-0.5):1.

[0082] It should be noted that the reaction temperature can also be 520℃, 530℃, 540℃, 560℃, 570℃, 580℃, 590℃, 600℃, 610℃, 630℃, 640℃, etc. In the method of this application, by controlling the catalytic cracking conditions in step (3) as described above, the catalytic cracking feedstock can be converted into more high-value products.

[0083] According to a specific embodiment of the method described in the first aspect of the present invention, the catalyst in step (3) comprises the following components, based on the dry weight of the components and the catalyst:

[0084] 1-50% zeolite, 5-99% inorganic oxides, and 0-70% clay;

[0085] The preferred composition is 5-45% zeolite, 10-80% inorganic oxides, and 5-60% clay.

[0086] More preferably, 10-40 wt% zeolite, 20-70 wt% inorganic oxides, and 10-50 wt% clay; and / or,

[0087] The method further includes the following steps:

[0088] This allows the residual oil from the heavy fraction of the crude oil in step (2) to be used as a feedstock for the production of needle coke and / or road asphalt.

[0089] It should be noted that, in one embodiment, the zeolite includes mesoporous zeolite and optionally macroporous zeolite, wherein the mesoporous zeolite is selected from ZSM series zeolite, ZRP zeolite, and any combination thereof; and the macroporous zeolite is selected from rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite, and high silica Y-type zeolite, and any combination thereof.

[0090] In one embodiment, the mesoporous zeolite accounts for 10-90% by weight, preferably 50-80% by weight, on a dry basis, of the total weight of the zeolite.

[0091] In this application, the terms mesoporous zeolite and macroporous zeolite are defined according to conventional definitions in the art, namely, the average pore size of mesoporous zeolite is about 0.5-0.6 nm, and the average pore size of macroporous zeolite is about 0.7-1.0 nm.

[0092] As an example, the macroporous zeolite may be selected from one or more of rare earth Y (REY) type zeolite, rare earth hydrogen Y (REHY) type zeolite, ultrastable Y type zeolite obtained by different methods, and high-silica Y type zeolite. The mesoporous zeolite may be selected from zeolites with an MFI structure, such as ZSM series zeolites and / or ZRP zeolite. Optionally, the above-mentioned mesoporous zeolites may be modified with non-metallic elements such as phosphorus and / or transition metal elements such as iron, cobalt, and nickel. A more detailed description of ZRP zeolite can be found in US Patent 5,232,675A. ZSM series zeolites are preferably selected from one or more mixtures of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48, and other zeolites with similar structures. A more detailed description of ZSM-5 can be found in US Patent 3,702,886A.

[0093] According to this application, the inorganic oxide, as a binder, is preferably silicon dioxide (SiO2) and / or aluminum oxide (Al2O3). The clay, as a matrix (i.e., carrier), is preferably kaolin and / or hydrous kaolin.

[0094] Secondly, the present invention relates to a system for producing high-value products with high crude oil utilization, such as... Figure 1 As shown, the system includes a distillation unit 100, an extraction and separation unit 200, and a catalytic cracking unit 400;

[0095] The distillation unit 100 is provided with a crude oil inlet 101, a crude oil light fraction outlet pipeline 102, and a crude oil heavy fraction outlet pipeline 103.

[0096] The crude oil heavy distillate outlet pipeline 103 is connected to the material inlet of the extraction and separation unit 200. The extraction and separation unit 200 is also provided with an extraction solvent inlet 201, an extracted oil outlet 202 for the crude oil heavy distillate, and a raffinate oil outlet 203 for the crude oil heavy distillate.

[0097] The catalytic cracking unit 400 is provided with a catalytic cracking feedstock inlet, a cracking gas outlet 401, a cracking light gasoline outlet 402, a cracking heavy gasoline outlet 403, a cracking diesel outlet 404, and a cracking heavy oil outlet 405.

[0098] The catalytic cracking feedstock inlet of the catalytic cracking unit 400 is connected to the crude oil extraction outlet 202 of the heavy fraction and the crude oil light fraction outlet pipeline 102, respectively.

[0099] The catalytic cracking unit 400 is also provided with an inlet for difficult-to-convert components.

[0100] It should be noted that crude oil enters the distillation unit 100 through crude oil inlet 101 for distillation and splitting. The resulting light and heavy fractions of crude oil are output through the light fraction outlet pipeline 102 and the heavy fraction outlet pipeline 103, respectively. After the heavy fraction is output, it enters the extraction and separation unit 200 for extraction and separation. The resulting extracted oil and raffinate are output through the extracted oil outlet 202 and the raffinate outlet 203, respectively. The extracted oil from the extraction and separation unit 200 and the light fraction from the distillation unit 100 enter the catalytic cracking unit 400, where they, together with the difficult-to-convert component entering through the first difficult-to-convert component inlet 406, serve as feedstock for catalytic cracking. After oil-gas separation and oil-gas separation, the resulting cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel, and cracked heavy oil are output through the cracked gas outlet 401, cracked light gasoline outlet 402, cracked heavy gasoline outlet 403, cracked diesel outlet 404, and cracked heavy oil outlet 405, respectively.

[0101] The system of this application may also include oil separation equipment and reaction product separation equipment. These can be equipment well known to those skilled in the art. For example, the oil separation equipment may include cyclone separators, settlers and strippers, while the reaction product separation equipment may be fractionation towers.

[0102] It should be noted that the method described in the first aspect of the present invention can be based on, but is not limited to, the system described in the second aspect of the present invention, and the system described in the second aspect of the present invention can be based on, but is not limited to, the method described in the first aspect of the present invention.

[0103] According to a specific embodiment of the system described in the second aspect of the present invention, the system is further provided with a gas separation unit, wherein the cracked gas outlet 401 is connected to the gas inlet to be separated of the gas separation unit, and the gas separation unit is provided with an ethylene outlet, a propylene outlet, a C4 component outlet, and other product outlets.

[0104] The C4 component outlet of the gas separation unit is connected to the difficult-to-convert component inlet of the catalytic cracking unit 400; the cracked light gasoline outlet 402 of the catalytic cracking unit 400 is connected to the difficult-to-convert component inlet.

[0105] It should be noted that, in this preferred embodiment, the C4 component generated by the gas separation unit and the cracked light gasoline generated by the catalytic cracking unit 400, together with the extracted oil from the light and heavy fractions of crude oil, are used as feedstocks for catalytic cracking. The C4 component and the cracked light gasoline can enter the catalytic cracking unit 400 through the difficult-to-convert component inlet. Specifically, they can enter through the same difficult-to-convert component inlet, or they can enter the catalytic cracking unit 400 through different difficult-to-convert component inlets.

[0106] According to a specific embodiment of the system described in the second aspect of the present invention, the system further includes a hydrogenation unit 300, wherein the cracked diesel outlet 404 of the catalytic cracking unit 400 is connected to the hydrogenation material inlet of the hydrogenation unit 300, and the hydrogenation unit 300 is further provided with a hydrogenated cracked diesel outlet.

[0107] Preferably, the catalytic cracking unit 400 is provided with a first difficult-to-convert component inlet 406, a crude oil light fraction inlet, a second difficult-to-convert component inlet 408, an extract oil inlet, and a hydrocracking diesel inlet 407 sequentially from upstream to downstream. The C4 component outlet is connected to the first difficult-to-convert component inlet 406, the crude oil light fraction outlet pipeline 102 is connected to the crude oil light fraction inlet, the cracked light gasoline outlet 402 is connected to the second difficult-to-convert component inlet 408, the crude oil heavy fraction extract oil outlet 202 is connected to the extract oil inlet, and the hydrocracking diesel outlet is connected to the hydrocracking diesel inlet 407.

[0108] It should be noted that, in this preferred embodiment, the cracked diesel produced by catalytic cracking is output through cracked diesel outlet 404 and then enters the hydrotreating unit 300 for hydrotreating. The resulting hydrotreated cracked diesel is output through the hydrotreated cracked diesel outlet and then enters the catalytic cracking unit 400 through the hydrotreated cracked diesel inlet 407 as a feedstock for catalytic cracking reaction. In this embodiment, the above-mentioned catalytic cracking feedstocks are introduced into the reactor of the catalytic cracking unit 400 sequentially through the above-mentioned different inlets. The upstream and downstream relationship of the feeding sequence or feeding position of the feedstocks is cleverly controlled, which is beneficial to further improve the yield of the target high-value product.

[0109] According to a specific embodiment of the system described in the second aspect of the present invention, the cracked diesel outlet 404 of the catalytic cracking unit 400 is connected to the catalytic cracking feedstock inlet;

[0110] Preferably, the catalytic cracking unit 400 is provided with a first difficult-to-convert component inlet 406, a crude oil light fraction inlet, a second difficult-to-convert component inlet 408, an extract oil inlet, and a cracked diesel inlet from upstream to downstream. The C4 component outlet is connected to the first difficult-to-convert component inlet 406, the crude oil light fraction outlet pipeline 102 is connected to the crude oil light fraction inlet, the cracked light gasoline outlet 402 is connected to the second difficult-to-convert component inlet 408, the crude oil heavy fraction extract oil outlet 202 is connected to the extract oil inlet, and the cracked diesel outlet 404 is connected to the cracked diesel inlet.

[0111] And / or,

[0112] The extraction and separation unit 200 is a supercritical extraction unit; and / or,

[0113] The system also includes a needle coke production unit and a road asphalt production unit, wherein the raffinate outlet 203 of the crude oil heavy fraction is connected to the raw material inlet of the needle coke production unit and / or the road asphalt production unit.

[0114] It should be noted that, in this preferred embodiment, the pyrolysis diesel produced in the catalytic cracking unit 400 is output through the pyrolysis diesel outlet 404 and then enters the catalytic cracking unit 400 again to undergo catalytic cracking reaction together with other catalytic cracking feedstocks. In this preferred embodiment, the aforementioned catalytic cracking feedstocks are sequentially introduced into the reactor of the catalytic cracking unit 400 through the aforementioned different inlets. The upstream and downstream relationship of the feeding sequence or feeding location of the feedstocks is cleverly controlled, which is beneficial to further improving the yield of the target high-value product.

[0115] According to a specific embodiment of the system described in the second aspect of the present invention, the reactor provided in the catalytic cracking unit 400 is selected from one or a combination of several of fluidized beds, turbulent beds, fast beds and dilute phase transport beds;

[0116] The reactor is one, two, or a combination of more, selected from one or two series combinations of constant linear velocity reactors, constant diameter reactors, variable diameter reactors, upward conveyor line reactors, and downward conveyor line reactors.

[0117] It should be noted that the gas velocity in the turbulent bed and fast bed reactors can be 0.1 m / s to 2 m / s, while the gas velocity in the dilute phase transport bed can be 2 m / s to 20 m / s.

[0118] In one embodiment, in order to enable the feedstock oil to react fully, the catalytic cracking reactor may be provided with one or more reaction zones, depending on the different catalytic cracking reaction performance of the feedstock. The reaction zones may be 2-8, preferably 2-3.

[0119] In one embodiment, the reactor of the catalytic cracking unit may be provided with one or more, such as one, two or more, crude oil heavy fraction extraction oil inlets, and the one or more crude oil heavy fraction extraction oil inlets may be independently provided in the catalytic cracking reactor.

[0120] In one embodiment, the reactor of the catalytic cracking unit may be provided with one or more, such as one, two or more, inlets for difficult-to-convert components, and the one or more inlets for difficult-to-convert components may be independently provided in the catalytic cracking reactor.

[0121] In one embodiment, the reactor of the catalytic cracking unit may be provided with one or more, such as one, two or more hydrocracking diesel inlets, which may be independently provided in the catalytic cracking reactor.

[0122] In one embodiment, the light hydrocarbons and light distillate oils of the difficult-to-convert components can be introduced into the catalytic cracking reactor at the same location as the reactor, or they can be introduced into the catalytic cracking reactor at different locations. Preferably, the light hydrocarbons are introduced into the catalytic cracking reactor at one or more locations upstream of the light distillate oil introduction location, which is beneficial to further improve the yield of the target product, i.e., the high-value product.

[0123] Figure 1 A preferred embodiment of the system for producing high-value products with high crude oil utilization of this application is provided.

[0124] like Figure 1 As shown, crude oil enters the distillation unit 100 through crude oil inlet 101 and is separated into light crude oil fraction and heavy crude oil fraction under the action of heat;

[0125] The separated crude oil heavy fraction enters the extraction separation unit 200 through the crude oil heavy fraction outlet pipeline 103, where it comes into contact with the extraction solvent from the extraction solvent inlet 201 and the components are separated to obtain extracted oil and raffinate oil. The extracted oil flows out through the crude oil heavy fraction extracted oil outlet 202 and is then sent to the catalytic cracking unit 400; the raffinate oil flows out through the crude oil heavy fraction raffinate oil outlet 203 and is then sent out of the unit as a raw material for the production of needle coke or road asphalt.

[0126] The light crude oil fraction from the light crude oil fraction outlet pipeline 102 and the extracted oil from the heavy crude oil fraction outlet pipeline 202 enter the catalytic cracking unit 400. Under the action of heat and catalytic cracking catalyst, a catalytic cracking reaction occurs. The reaction products are separated to obtain cracked gas (outflow from cracked gas outlet 401), cracked light gasoline (outflow from cracked light gasoline outlet 402), cracked heavy gasoline (outflow from cracked heavy gasoline outlet 403), cracked diesel (outflow from cracked diesel outlet 404), and cracked heavy oil (outflow from cracked heavy oil outlet 405). The cracked gas can be further separated to obtain ethylene, propylene, C4 fraction, and other products. The C4 fraction and cracked light gasoline, as difficult-to-convert components, are returned to the catalytic cracking unit through the difficult-to-convert component inlet for further conversion into high-value products. The cracked diesel is sent to the hydrotreating unit 300 after flowing out through the cracked diesel outlet 404. Under the action of hydrogen and hydrotreating catalyst, a hydrorefining reaction occurs. The reaction products enter the catalytic cracking unit through the hydrotreating cracked diesel inlet 407 for further catalytic cracking reaction.

[0127] The present invention will be further described in detail below through examples, but these examples are not intended to limit the invention. In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0128] The feedstock used in the following examples and comparative examples is Kuwaiti crude oil, the properties of which are shown in Table 1. The catalyst used in the catalytic cracking unit is a commercial catalytic cracking catalyst purchased from the Catalyst Division of China Petroleum & Chemical Corporation (Sinopec), with the trade name DMMC-2. The trade name of the hydrotreating catalyst is RN-32L.

[0129] In this application, the yield of high-value products refers to the total yield of low-carbon olefins (ethylene, propylene, butene), light aromatics (BTX), and the production of needle coke or road asphalt components (residue oil from heavy crude oil fractions). The yield of products such as ethylene and propylene refers to their weight percentage in crude oil.

[0130] Table 1 Properties of the crude oil used

[0131]

[0132] Example 1

[0133] use Figure 1 The system shown separates Kuwaiti crude oil from Table 1 into light and heavy fractions by true boiling point distillation. The cutoff point between the light and heavy fractions is approximately 300°C, and the yields of the light and heavy fractions are 34.24% and 65.76%, respectively.

[0134] In the extraction and separation unit, propane is used as a solvent to separate the heavy fraction of crude oil using supercritical extraction to obtain extract oil and raffinate oil. The yield of extract oil is 76.2% (the proportion of extract oil in the heavy fraction of crude oil = 50.11% ÷ 65.76%), the mass fraction of saturated components in the extract oil is 52.4%, the heavy metal removal rate is above 96%, and the asphaltene removal rate is 99%. The properties of the obtained raffinate oil are suitable for use as a raw material for road asphalt.

[0135] In the hydrotreating unit, the cracked diesel fuel obtained from the catalytic cracking reaction comes into contact with the hydrotreating catalyst and undergoes a polycyclic aromatic hydrocarbon saturation reaction. The resulting hydrotreating product (hydrocracked diesel fuel) is used as feed for the catalytic cracking unit.

[0136] In the catalytic cracking unit, a small-scale fixed fluidized bed reactor was used for catalytic cracking reaction experiments. The feedstocks were light crude oil fraction, extract oil from heavy crude oil fraction, C4 components (obtained from the gas separation of cracked gases), cracked light gasoline (obtained from the catalytic cracking reaction), and hydrocracking diesel. Before the experiment, the catalyst was loaded into the reactor, and the reactor was heated to the reaction temperature while maintaining the catalyst in a fluidized state. Based on the catalytic cracking reaction performance of the feedstocks, the feedstock feeding order (from upstream to downstream) was C4 components, light crude oil fraction, cracked light gasoline, extract oil from heavy crude oil fraction, and hydrocracking diesel. All feedstocks were preheated and mixed with high-temperature steam, then fed into the bottom of the fluidized bed reactor through the feed nozzle, where they reacted on the hot catalyst. After the reaction, steam was introduced for stripping, and the reaction oil and gas entered a multi-stage condensation separation system for separation, yielding cracked gas products and liquid products. The yields of both gaseous and liquid products were measured, and the gaseous products entered the separation system for further separation into C4 components and other gases. After the reaction, the reactor automatically heats up to the regeneration temperature, and oxygen is simultaneously introduced into the reactor to regenerate the spent catalyst through coking. The real-time CO2 concentration of the regenerated flue gas is measured by an infrared analyzer, and the coke yield is calculated based on the integral of the flue gas flow rate. The gaseous products are collected and their composition is analyzed by offline chromatography, while the liquid products are analyzed by simulated distillation chromatography to obtain the mass fractions of cracked gasoline (cracking light gasoline and cracked heavy gasoline), cracked diesel, and cracked heavy oil.

[0137] The reaction conditions and product yields for different units are listed in Tables 2 and 3. As can be seen from Table 3, the ethylene yield in this embodiment reached 12.91% by weight, the propylene yield reached 24.85% by weight, the light aromatics (BTX) yield reached 9.70% by weight, the high-value product yield reached 67.52%, and the coke yield was 10.35%.

[0138] Example 2

[0139] use Figure 1The system shown operates the same as in Example 1 in terms of extraction and separation unit operation. There is no hydrogenation unit; the catalytic cracking unit produces cracked diesel oil, which is directly used as the cracking feedstock. The catalytic cracking unit operation steps are the same as in Example 1, and the feedstock order (from upstream to downstream) is: C4 components, light crude oil fraction, cracked light gasoline, extract oil from heavy crude oil fraction, and cracked diesel oil.

[0140] The reaction conditions and product yields for different units are listed in Tables 2 and 3. As can be seen from Table 3, the ethylene yield in this embodiment reached 12.69% by weight, the propylene yield reached 24.32% by weight, the light aromatics (BTX) yield reached 9.55% by weight, the high-value product yield reached 66.77%, and the coke yield was 10.42%.

[0141] Comparative Example 1

[0142] There is no crude oil distillation process; the crude oil goes directly into the catalytic cracking unit.

[0143] Using Kuwaiti crude oil and DMMC-2 catalyst as shown in Table 1, a small-scale fixed fluidized bed reactor was used for catalytic cracking experiments. Before the experiment, the catalyst was loaded into the reactor, and the reactor was heated to the reaction temperature while maintaining the catalyst in a fluidized state. The feedstock, after preheating, was mixed with high-temperature steam and fed into the bottom of the fluidized bed through the feed nozzle, where it reacted on the hot catalyst. After the reaction, steam was introduced for stripping, and the reaction oil and gas were separated in a multi-stage condensation separation system to obtain cracked gaseous and liquid products. The yields of both gaseous and liquid products were measured. After the reaction, the reactor was automatically heated to the regeneration temperature, and oxygen was simultaneously introduced into the reactor to regenerate the spent catalyst through coke burning. The real-time CO2 concentration of the regenerated flue gas was measured using an infrared analyzer, and the coke yield was calculated based on the integral of the flue gas flow rate. The gaseous products were collected and their composition was analyzed using offline chromatography, while the liquid products were analyzed using simulated distillation chromatography to obtain the mass fractions (%) of cracked gasoline, cracked diesel, and cracked heavy oil. The reaction conditions and product distribution are listed in Tables 2 and 3.

[0144] As can be seen from the results in Table 3, the yield of ethylene in this comparative example is only 5.56% by weight, the yield of propylene is only 15.85% by weight, the yield of light aromatics (BTX) is 6.34%, the yield of high-value products is 39.04%, and the yield of coke is as high as 13.12%.

[0145] Comparative Example 2

[0146] Using the true boiling point distillation method shown in Example 1, Kuwaiti crude oil was separated into light crude oil fraction and heavy crude oil fraction, which were then fed into a catalytic cracking reactor.

[0147] Catalytic cracking experiments were conducted using a small-scale fixed fluidized bed reactor. Before the experiment, the catalyst was loaded into the reactor and kept in a fluidized state while the reactor was heated to the reaction temperature. First, the light fraction of crude oil was mixed with high-temperature steam and fed into the bottom of the fluidized bed reactor through the feed nozzle, where it reacted on the hot catalyst. Then, the preheated heavy fraction of crude oil was mixed with high-temperature steam and fed into the bottom of the fluidized bed reactor through the feed nozzle, where it reacted on the hot catalyst. After the reaction, steam was introduced for stripping, and the reaction mixture was separated into pyrolysis gaseous and liquid products by a multi-stage condensation separation system. The yields of both gaseous and liquid products were measured. After the reaction, the reactor was automatically heated to the regeneration temperature, and oxygen was introduced into the reactor to regenerate the spent catalyst through coking. The real-time CO2 concentration of the regenerated flue gas was measured using an infrared analyzer, and the coke yield was calculated based on the integral of the flue gas flow rate. The gaseous products were collected and analyzed using offline chromatography, while the liquid products were analyzed using simulated distillation chromatography to obtain the mass fractions of cracked gasoline, cracked diesel, and cracked heavy oil. The reaction conditions and product distribution are listed in Tables 2 and 3.

[0148] As can be seen from the results in Table 3, the yield of ethylene in this comparative example is only 10.01% by weight, the yield of propylene is only 12.81% by weight, the yield of light aromatics (BTX) is 8.40%, the yield of high-value products is 41.88%, and the yield of coke is as high as 12.71%.

[0149] Table 2 Reaction conditions for the Examples and Comparative Examples

[0150]

[0151] The percentage of water vapor used (by weight) indicates the proportion of water vapor in the total weight of the catalytic cracking feedstock.

[0152] The amount of catalytic cracking feedstock does not include difficult-to-convert components (C4 components and cracked light gasoline) in the following weight ratios: catalyst to catalytic cracking feedstock, proportion of difficult-to-convert components in catalytic cracking feedstock, and proportion of (hydrogenated) cracked diesel in catalytic cracking feedstock.

[0153] Table 3 Comparison of reaction results between the examples and comparative examples

[0154]

[0155] As can be seen from the results of the above embodiments and comparative examples, when the catalytic cracking method and system of this application are used for crude oil catalytic cracking reaction, the yields of ethylene and propylene are significantly increased, the yield of high-value products is high, and the yield of coke is reduced, that is, the crude oil atom utilization rate is high and the carbon emissions of the process are greatly reduced.

[0156] In the description of this application, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0157] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0158] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A method for producing high-value products with high crude oil utilization, characterized in that, The method includes the following steps: (1) Distill crude oil to obtain light crude oil fraction and heavy crude oil fraction; wherein the cutting point of the light crude oil fraction and the heavy crude oil fraction is 240-350℃; (2) Extract and separate the crude oil heavy fraction to obtain crude oil extract and crude oil residue. (3) In a catalytic cracking reactor, the catalytic cracking feedstock is brought into contact with the catalyst to carry out a catalytic cracking reaction, and cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel and cracked heavy oil are obtained by oil-gas separation; the catalytic cracking feedstock includes the light fraction of crude oil, the extracted oil of the heavy fraction of crude oil and difficult-to-convert components; wherein, the difficult-to-convert components include light hydrocarbons and light distillate oil; The method further includes separating the pyrolysis gas from step (3) to obtain ethylene, propylene, C4 components and other products, wherein the light hydrocarbons of the difficult-to-convert components include the C4 components, and the light distillate oil of the difficult-to-convert components includes the pyrolysis light gasoline obtained from step (3). The C4 component, the light crude oil fraction, the cracked light gasoline, and the crude oil heavy fraction extract oil are each introduced into the catalytic cracking reactor independently at different locations; the feed inlets for the C4 component, the light crude oil fraction, the cracked light gasoline, and the crude oil heavy fraction extract oil are sequentially arranged from upstream to downstream of the catalytic cracking reactor.

2. The method according to claim 1, characterized in that, The light distillate oils containing the difficult-to-convert components include light distillate oils with a final boiling point of less than 280-350℃.

3. The method according to claim 2, characterized in that, The method further includes the following steps: The cracked diesel from step (3) is subjected to hydrotreating to obtain hydrocracked diesel; The catalytic cracking feedstock in step (3) also includes the hydrocracking diesel.

4. The method according to claim 3, characterized in that, The weight percentages of the C4 component, which is the difficult-to-convert component, and the cracked light gasoline in the catalytic cracking feedstock are each 5-20%; The hydrocracking diesel fuel accounts for 5-30% of the weight of the catalytic cracking feedstock.

5. The method according to claim 2, characterized in that, The catalytic cracking feedstock mentioned in step (3) also includes the cracked diesel oil; The C4 components, the light crude oil fraction, the cracked light gasoline, the extracted oil from the heavy crude oil fraction, and the cracked diesel are introduced into the catalytic cracking reactor at their respective independent locations. And / or, The weight percentages of the C4 component, which is the difficult-to-convert component, and the cracked light gasoline in the catalytic cracking feedstock are each 5-20%; The cracked diesel fuel accounts for 5-30% of the weight of the catalytic cracking feedstock.

6. The method according to claim 1, characterized in that, In step (1), The crude oil is selected from one or more of the following: paraffinic crude oil, paraffinic-intermediate crude oil, intermediate-paraffinic crude oil, and intermediate-based crude oil; and / or, The crude oil meets at least one of the following criteria: The density at 20℃ is 835-935 kg / m³. 3 The API content is greater than 28, the UOP K value is not less than 11.5, and the metal content is greater than 30 mg / kg.

7. The method according to claim 1, characterized in that, In step (2), The yield of the extracted oil from the heavy fraction of the crude oil is greater than 50% by weight; and / or, The extracted oil from the heavy fraction of the crude oil contains a saturated fraction content greater than 45% by weight; and / or, The heavy metal removal rate of the extracted oil from the crude oil heavy fraction is greater than 80% by weight; and / or, The asphaltene removal rate of the extracted oil from the heavy fraction of the crude oil is greater than 90%.

8. The method according to claim 1, characterized in that, In step (3), the light hydrocarbons of the difficult-to-convert components include gaseous hydrocarbons rich in C4 fractions produced by other devices or processes; The light distillate oil containing the difficult-to-convert components is selected from one or more of the following oil products: Other primary processing units produce straight-run naphtha, straight-run kerosene, and straight-run diesel, as well as secondary processing products such as topping oil, residue oil, hydrocracking light naphtha, pentane oil, coking gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrotreated gasoline, and hydrotreated diesel.

9. The method according to claim 1, characterized in that, In step (2), The extraction separation is supercritical fluid extraction separation, and the extraction solvent used is selected from one or a mixture of several of ethane, propane, n-butane, isobutane, n-pentane, isopentane, hexane, heptane, and octane; and / or, The extraction and separation conditions include: a temperature of 50-100℃, a pressure of 6-20 MPa, and a weight ratio of the extraction solvent to the crude oil heavy fraction of (2-5):

1.

10. The method according to any one of claims 1-5, characterized in that, In step (3), the conditions for the catalytic cracking reaction include: The catalytic cracking feedstock is mixed with water vapor and then fed into the reaction. The reaction temperature is 510-650℃ and the reaction time is 1-20 seconds. The weight ratio of the catalyst to the catalytic cracking feedstock is (3-50):1, and the weight ratio of the water vapor to the catalytic cracking feedstock is (0.03-0.8):

1.

11. The method according to claim 1, characterized in that, Based on the dry weight of the components and the catalyst, the catalyst in step (3) comprises the following components: 1-50 wt% zeolite, 5-99 wt% inorganic oxides, and 0-70 wt% clay; and / or, The method further includes the following steps: This allows the residual oil from the heavy crude oil fraction of step (2) to be used as a feedstock for the production of needle coke and / or road asphalt.

12. The method according to claim 4, characterized in that, The feed inlets for the C4 component, the light crude oil fraction, the cracked light gasoline, the extracted oil from the heavy crude oil fraction, and the hydrocracking diesel are sequentially arranged from upstream to downstream of the catalytic cracking reactor.

13. The method according to claim 5, characterized in that, The feed inlets for the C4 component, the light crude oil fraction, the cracked light gasoline, the extracted oil from the heavy crude oil fraction, and the cracked diesel are sequentially arranged from upstream to downstream of the catalytic cracking reactor.

14. The method according to claim 7, characterized in that, The yield of the extracted oil from the heavy fraction of the crude oil is greater than 65% by weight; and / or, The content of saturated fraction in the extracted oil of the crude oil heavy fraction is greater than 50% by weight; and / or, The heavy metal removal rate of the extracted oil from the crude oil heavy fraction is greater than 90% by weight; and / or, The asphaltene removal rate of the extracted oil from the heavy fraction of the crude oil is greater than 95%.

15. The method according to claim 8, characterized in that, The light hydrocarbons of the difficult-to-convert components include C4 fractions produced by other units or processes.

16. The method according to claim 10, characterized in that, In step (3), the conditions for the catalytic cracking reaction include: The catalytic cracking feedstock is mixed with water vapor and then fed into the reaction. The reaction temperature is 550-620℃ and the reaction time is 2-10 seconds. The weight ratio of the catalyst to the catalytic cracking feedstock is (10-30):1, and the weight ratio of the water vapor to the catalytic cracking feedstock is (0.10-0.5):

1.

17. The method according to claim 11, characterized in that, Based on the dry weight of the components and the catalyst, the catalyst in step (3) comprises the following components: 5-45 wt% zeolite, 10-80 wt% inorganic oxides, and 5-60 wt% clay.

18. The method according to claim 11, characterized in that, Based on the dry weight of the components and the catalyst, the catalyst in step (3) comprises the following components: 10-40 wt% zeolite, 20-70 wt% inorganic oxides, and 10-50 wt% clay.

19. A system for producing high-value products with high crude oil utilization rate, characterized in that, The system includes a distillation unit (100), an extraction and separation unit (200), and a catalytic cracking unit (400). The distillation unit (100) is provided with a crude oil inlet (101), a crude oil light fraction outlet pipeline (102), and a crude oil heavy fraction outlet pipeline (103). The crude oil heavy distillate outlet pipeline (103) is connected to the material inlet of the extraction separation unit (200). The extraction separation unit (200) is also provided with an extraction solvent inlet (201), an extracted oil outlet (202) of the crude oil heavy distillate and a raffinate oil outlet (203) of the crude oil heavy distillate. The catalytic cracking unit (400) is provided with a catalytic cracking feedstock inlet, a cracked gas outlet (401), a cracked light gasoline outlet (402), a cracked heavy gasoline outlet (403), a cracked diesel outlet (404), and a cracked heavy oil outlet (405). The catalytic cracking feedstock inlet of the catalytic cracking unit (400) is connected to the crude oil extraction outlet (202) of the heavy fraction and the crude oil light fraction outlet pipeline (102), respectively. The catalytic cracking unit (400) is also provided with an inlet for difficult-to-convert components; The system is further provided with a gas separation unit, and the cracked gas outlet (401) is connected to the gas inlet to be separated of the gas separation unit. The gas separation unit is provided with an ethylene outlet, a propylene outlet, a C4 component outlet and other product outlets. The C4 component outlet of the gas separation unit is connected to the difficult-to-convert component inlet of the catalytic cracking unit (400); the cracked light gasoline outlet (402) of the catalytic cracking unit (400) is connected to the difficult-to-convert component inlet.

20. The system according to claim 19, characterized in that, The system also includes a hydrogenation unit (300), the cracked diesel outlet (404) of the catalytic cracking unit (400) is connected to the hydrogenation material inlet of the hydrogenation unit (300), and the hydrogenation unit (300) is also provided with a hydrogenated cracked diesel outlet.

21. The system according to claim 19, characterized in that, The cracked diesel outlet (404) of the catalytic cracking unit (400) is connected to the catalytic cracking feedstock inlet; And / or, The extraction and separation unit (200) is a supercritical extraction unit; and / or, The system also includes a needle coke production unit and a road asphalt production unit, wherein the raffinate outlet (203) of the crude oil heavy fraction is connected to the feed inlet of the needle coke production unit and / or the road asphalt production unit.

22. The system according to claim 19, characterized in that, The reactor in the catalytic cracking unit (400) is selected from one or a combination of fluidized bed, turbulent bed, fast bed and dilute phase transport bed; The reactor is one, two, or a combination of more, selected from one or two series combinations of constant linear velocity reactors, constant diameter reactors, variable diameter reactors, upward conveyor line reactors, and downward conveyor line reactors.

23. The system according to claim 20, characterized in that, The catalytic cracking unit (400) is provided with a first difficult-to-convert component inlet (406), a crude oil light fraction inlet, a second difficult-to-convert component inlet (408), an extract oil inlet, and a hydrocracking diesel inlet (407) in sequence from upstream to downstream. The C4 component outlet is connected to the first difficult-to-convert component inlet (406), the crude oil light fraction outlet pipeline (102) is connected to the crude oil light fraction inlet, the cracked light gasoline outlet (402) is connected to the second difficult-to-convert component inlet (408), the crude oil heavy fraction extract oil outlet (202) is connected to the extract oil inlet, and the hydrocracking diesel outlet is connected to the hydrocracking diesel inlet (407).

24. The system according to claim 21, characterized in that, The catalytic cracking unit (400) is provided with a first difficult-to-convert component inlet (406), a crude oil light fraction inlet, a second difficult-to-convert component inlet (408), an extract oil inlet, and a hydrocracking diesel inlet (407) in sequence from upstream to downstream. The C4 component outlet is connected to the first difficult-to-convert component inlet (406), the crude oil light fraction outlet pipeline (102) is connected to the crude oil light fraction inlet, the cracked light gasoline outlet (402) is connected to the second difficult-to-convert component inlet (408), the crude oil heavy fraction extract oil outlet (202) is connected to the extract oil inlet, and the hydrocracking diesel outlet is connected to the hydrocracking diesel inlet (407).

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