Process method and system for producing high value-added product from crude oil

Abstract

The invention relates to a process method and system for producing a high-added-value product from crude oil, and the method comprises the following steps: (1) carrying out distillation cutting on the crude oil to obtain light oil, intermediate oil and heavy oil; (2) carrying out first separation on the light oil to obtain a first saturated component and a first unsaturated component; (3) carrying out second separation on the intermediate oil to obtain a second saturated component and a second unsaturated component; (4) carrying out third separation on the heavy oil to obtain a third saturated component and a third unsaturated component; (5) contacting the catalytic cracking raw material with a catalyst to carry out catalytic cracking reaction, and carrying out oil-gas separation to obtain cracked gas, cracked light gasoline, cracked heavy gasoline, cracked diesel oil and cracked heavy oil; the catalytic cracking raw material comprises a first saturated component, a second saturated component, a third saturated component and an optional difficult-to-convert component, and the difficult-to-convert component comprises light hydrocarbon and / or light distillate oil. The method is high in crude oil adaptability, high in crude oil utilization rate, high in yield of high-added-value products and high in online rate of the device.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical engineering, and in particular to a process method and system for producing high value-added products from crude oil. Background Art

[0002] Refining capacity is in excess, and the demand for refined oil products is slowing down. Ethylene, propylene and BTX (benzene-toluene-xylene) are key basic organic synthetic raw materials with huge demand, while the demand for chemical products continues to be strong. The existing technical route for producing propylene and BTX from petroleum is developed on the basis of the traditional petroleum refining process that mainly produces oil products. There are problems such as long production process, low chemical yield and insignificant economic benefits. The technical measures to solve this problem are to develop key core technologies that mainly produce chemicals and can direct the conversion of crude oil hydrocarbon molecules into chemicals. Therefore, in recent years, international petrochemical companies represented by ExxonMobil and Saudi Aramco have begun to innovate traditional refining processes. These companies have subverted the traditional refining process and promoted the integration of refining and chemical to a new level of direct production of chemicals from crude oil.

[0003] ExxonMobil Corporation of the United States is a pioneer in the research and development of crude oil steam cracking to produce olefins. It was the first company to build an industrial demonstration unit and applied for a series of patents, such as CN 200580016314.X. The process method of the company's crude oil direct chemicals is that the crude oil directly enters the steam cracking furnace, and the light components and recombinant components are separated through flash evaporation. The light components (gaseous components) enter the steam cracking furnace for cracking, and the recombinant components (liquid components) are used as refinery raw materials. If the selected crude oil is light enough, there is no fraction above 593°C, that is, no bottom residue oil, and it does not need to rely on a refinery. The company's first industrial unit uses ultra-light paraffin-based tapis crude oil with an API gravity of 42.7 as raw material.

[0004] The technical characteristics of Saudi Aramco National Oil Company are that it adopts crude oil pretreatment technology and hydroprocessing technology to minimize the impact of non-volatile components in crude oil on steam cracking. At the same time, a vapor-liquid (steam and liquid) separation device is installed between the convection section and the radiation section of the steam cracking furnace to remove non-volatile liquid (liquid phase), ensuring that the material entering the radiation section does not carry liquid, thereby ensuring that the furnace tube does not coke, and the heavy components enter the catalytic cracking unit. It can be said that it is a process for producing olefins and aromatics from crude oil that integrates hydroprocessing, steam cracking and catalytic cracking processes.

[0005] Due to the presence of heavy components in crude oil that are difficult to vaporize, the existing crude oil direct chemical technology is only suitable for low-sulfur paraffin-based crude oil with an API degree of about 45. Other crude oil chemical technologies are different according to the different processing processes of heavy components in crude oil. The crude oil chemical technology routes of major companies are different, but they all use fraction cutting and combine process technologies according to the properties of distillate oils with different distillation ranges to achieve crude oil production chemicals. Compared with the traditional refining process, only the distillation range and quantity of the cut distillate oils are changed, and then the existing processing technology is integrated, which fails to achieve fundamental technological changes. In addition, these existing combined technologies are more suitable for light crude oil or paraffin-based crude oil. When using inferior crude oil such as heavy crude oil or intermediate-based crude oil as raw materials, the yield of chemicals such as high value-added products is low.

[0006] How to efficiently convert crude oil into high-value products such as low-carbon olefins and light aromatics to maximize the reaction efficiency and process selectivity and the utilization of crude oil resources at the molecular level is a technical problem that needs to be solved urgently. Summary of the invention

[0007] The present invention provides a process method and system for producing high value-added products from crude oil, the purpose of which is to better convert crude oil into high-value products such as low-carbon olefins and light aromatics, increase the yield of high-value products, and maximize the utilization of crude oil resources at the molecular level.

[0008] In a first aspect, the present invention relates to a process for producing high value-added products from crude oil, the process comprising the following steps:

[0009] (1) subjecting crude oil to distillation and cutting to obtain light oil, intermediate oil and heavy oil; wherein the cutting point between the light oil and the intermediate oil is 160-220° C., and the cutting point between the intermediate oil and the heavy oil is 260-320° C.;

[0010] (2) subjecting the light oil to a first separation to obtain a first saturated fraction and a first unsaturated fraction;

[0011] (3) subjecting the intermediate oil to a second separation to obtain a second saturated fraction and a second unsaturated fraction;

[0012] (4) subjecting the heavy oil to a third separation to obtain a third saturated fraction and a third unsaturated fraction;

[0013] (5) contacting the catalytic cracking feedstock with the catalyst to perform a catalytic cracking reaction, and obtaining cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil through oil and gas separation;

[0014] The catalytic cracking feedstock comprises the first saturated fraction, the second saturated fraction, the third saturated fraction and optional difficult-to-convert components, and the difficult-to-convert components include light hydrocarbons and / or light distillate oil.

[0015] In a second aspect, the present invention relates to a system for producing high value-added products from crude oil, the system comprising a distillation unit, a first separation unit, a second separation unit, a third separation unit and a catalytic cracking reaction unit;

[0016] The distillation unit is provided with a crude oil inlet, a light distillate oil outlet, a middle distillate oil outlet and a heavy distillate oil outlet;

[0017] The light fraction oil outlet of the distillation unit is connected to the inlet of the material to be separated of the first separation unit, and the first separation unit is also provided with a first saturated fraction outlet and a first unsaturated fraction outlet;

[0018] The middle distillate oil outlet of the distillation unit is connected to the inlet of the material to be separated of the second separation unit, and the second separation unit is also provided with a second saturated outlet and a second unsaturated outlet;

[0019] The heavy fraction oil outlet of the distillation unit is connected to the inlet of the material to be separated of the third separation unit, and the third separation unit is also provided with a third saturated fraction outlet and a third unsaturated fraction outlet;

[0020] The first saturated outlet, the second saturated outlet and the third saturated outlet are respectively connected to the catalytic cracking feedstock inlet of the catalytic cracking reaction unit; the catalytic cracking reaction unit is also provided with a cracking gas outlet, a cracking light gasoline outlet, a cracking heavy gasoline outlet, a cracking diesel outlet and a cracking heavy oil outlet.

[0021] Beneficial effects:

[0022] 1) The crude oil has strong adaptability. The process method of combining crude oil component separation and catalytic cracking units can convert intermediate base crude oil or lower quality naphthenic crude oil into high value-added products;

[0023] 2) High crude oil utilization rate. Since the size and structure of aromatics in the distillate oils of different distillation ranges of inferior crude oil are quite different, the components composed of different hydrocarbons can be separated and targeted and selective catalytic conversion can be carried out according to the characteristics of the components, which can improve the selectivity of the process and achieve efficient utilization of crude oil;

[0024] 3) The yield of high value-added products is high. The unsaturated fractions rich in aromatics in light distillate oil and middle distillate oil can be directly used as aromatic components or high-octane gasoline blending components. The heavy distillate oil rich in polycyclic aromatics or asphaltene can be used as needle coke or road asphalt raw materials according to different properties. The saturated fractions are converted into light olefins and aromatics as catalytic cracking raw materials. The yield of high value-added products in the whole process reaches 70%;

[0025] 4) The online rate of the device is high. Inferior crude oil has high residual carbon, high metal and high asphaltene content. After component separation, the quality of the catalytic cracking raw material is greatly improved. Not only is the yield of the target product high, but the operation cycle is also extended and the online rate is increased, thereby effectively improving the economic benefits.

[0026] The process method or system for producing high value-added products from crude oil of the present application can efficiently produce low-carbon olefins and light aromatics and other high-value-added products from inferior crude oil, which can not only produce high-value chemical raw materials and promote the deep integration of oil refining and petrochemical industries, but also effectively respond to the challenges brought about by the shortage of oil resources; not only does it have good crude oil adaptability and high chemical yield, but it also produces other high value-added chemical raw materials as by-products, and the crude oil utilization rate is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a system for producing high value-added products from crude oil in the present application;

[0028] Description of Reference Numerals

[0029] 100 Distillation unit 101 Crude oil inlet 201a Light distillate oil outlet

[0030] 202a Middle distillate oil outlet 203a Heavy distillate oil outlet 201 First separation unit

[0031] 202 second separation unit 203 third separation unit 400 catalytic cracking reaction unit

[0032] 201b first saturated outlet 201c first unsaturated outlet 202b second saturated outlet

[0033] 202c second unsaturated outlet 203b third saturated outlet 203c third unsaturated outlet

[0034] 401 cracking gas outlet 402 cracking light gasoline outlet 403 cracking heavy gasoline outlet

[0035] 404 cracking diesel outlet 405 cracking heavy oil outlet 300 hydrogenation reaction unit

[0036] 301 Hydrogenation product outlet 406 Difficult-to-convert component inlet DETAILED DESCRIPTION

[0037] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0038] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0039] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0040] Any specific numerical value disclosed herein (including the endpoint of the numerical range) is not limited to the exact value of the numerical value, but should be understood to also cover values ​​close to the exact value, such as all possible numerical values ​​within the range of ±5% of the exact value. In addition, for the disclosed numerical range, the endpoint values ​​of the range, the endpoint values ​​and the specific point values ​​in the range, and the specific point values ​​can be arbitrarily combined to obtain one or more new numerical ranges, and these new numerical ranges should also be regarded as specifically disclosed herein.

[0041] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0042] In a first aspect, the present invention relates to a process for producing high value-added products from crude oil, the process comprising the following steps:

[0043] (1) subjecting crude oil to distillation and cutting to obtain light oil, intermediate oil and heavy oil; wherein the cutting point between the light oil and the intermediate oil is 160-220° C., and the cutting point between the intermediate oil and the heavy oil is 260-320° C.;

[0044] (2) subjecting the light oil to a first separation to obtain a first saturated fraction and a first unsaturated fraction;

[0045] (3) subjecting the intermediate oil to a second separation to obtain a second saturated fraction and a second unsaturated fraction;

[0046] (4) subjecting the heavy oil to a third separation to obtain a third saturated fraction and a third unsaturated fraction;

[0047] (5) contacting the catalytic cracking feedstock with the catalyst to carry out a catalytic cracking reaction, and obtaining cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil through oil and gas separation;

[0048] The catalytic cracking feedstock comprises the first saturated fraction, the second saturated fraction, the third saturated fraction and optional difficult-to-convert components, and the difficult-to-convert components include light hydrocarbons and / or light distillate oil.

[0049] It should be noted that light oil, intermediate oil and heavy oil are abbreviations for light distillate oil, intermediate distillate oil and heavy distillate oil, respectively. The optional difficult-to-convert component means that the catalytic cracking feedstock may not contain the difficult-to-convert component, or may contain any proportion of the difficult-to-convert component. The light hydrocarbons and / or light distillate oil of the difficult-to-convert component may be obtained from the process of the present application or introduced from the outside.

[0050] It should be noted that in the process method of the present application, in step (1), crude oil is cut and separated into light, medium and heavy fractions according to different distillation ranges. As a preferred embodiment, cutting is performed according to the above-mentioned cutting points to obtain light oil, intermediate oil and heavy oil; in steps (2)-(4), the fractions of different distillation ranges are separated into components to obtain saturated fractions and unsaturated fractions, respectively, wherein the obtained saturated fractions are rich in saturated hydrocarbons and the obtained unsaturated fractions are rich in aromatic hydrocarbons; in step (5), the saturated fractions rich in paraffins and cycloalkanes obtained from steps (2)-(4) are used as catalytic cracking raw materials, and catalytic cracking reactions occur under high temperature and the action of a catalyst, and the reaction products can be separated to obtain high-value products such as low-carbon olefins and light aromatic hydrocarbons.

[0051] The process method of the present application first distills and cuts the crude oil according to the above-mentioned cutting points, and then separates the distillate oils of different distillation ranges obtained by cutting into saturated fractions and unsaturated fractions, and uses the obtained three saturated fractions as catalytic cracking raw materials for catalytic cracking reaction. This process method of the present application can better convert crude oil into high-value products such as low-carbon olefins and light aromatics, and significantly improve the yield of high value-added products. The yield of high value-added products in the present application refers to the total yield of low-carbon olefins (ethylene, propylene, butene), light aromatics BTX (benzene, toluene and xylene), the first unsaturated fraction, the second unsaturated fraction, and the third unsaturated fraction.

[0052] It should be noted that in step (1), the cut point between light oil and intermediate oil can be specifically 170°C, 180°C, 190°C, 200°C, 210°C, 215°C, etc., and the cut point between intermediate oil and heavy oil can be specifically 265°C, 270°C, 280°C, 290°C, 300°C, 310°C, 315°C, etc. In step (5), after the catalytic cracking reaction, cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil are obtained through the steps of oil agent separation, oil-gas separation, etc., and the separation process involved can adopt conventional separation methods in the art, or methods well known to those skilled in the art.

[0053] According to a specific embodiment of the process method described in the first aspect of the present invention, the crude oil in step (1) is selected from one or more mixed crude oils of intermediate base crude oil, intermediate base-cycloalkyl crude oil and cycloalkyl-intermediate base crude oil.

[0054] It should be noted that any one of the first key component and the second key component of the intermediate base crude oil belongs to the intermediate base attribute; the first key component of the intermediate base-cycloalkyl crude oil is the intermediate base attribute and the second key component is the cycloalkyl attribute; the first key component of the cycloalkyl-intermediate base crude oil is the cycloalkyl attribute and the second key component is the intermediate base attribute. The process method of the present application can distill, cut and separate the above-mentioned inferior oils, catalytically crack the saturated components, and then produce high-value products such as low-carbon olefins and light aromatics with high yields.

[0055] It should be noted that the inventors of the present application have developed the process method for producing high value-added products from crude oil of the present application after many years of research and development. The process method of the present application has strong adaptability to raw materials, is particularly suitable for inferior crude oil, has a high yield of high value-added products, and can achieve efficient utilization of inferior crude oil resources. Therefore, the process method of the present application can be called a method for producing high value-added products from inferior crude oil.

[0056] According to another specific embodiment of the process method of the first aspect of the present invention, the first separation in step (2) comprises: contacting the light oil with a first solvent to perform a first extraction separation;

[0057] Wherein, the first solvent is selected from one or more combinations of sulfolane, methyl sulfolane, dimethyl sulfolane and polyglycol ether solvents;

[0058] The conditions for the first extraction separation include: a temperature of 60-180° C., a pressure of 0.3-1.2 MPa, and a weight ratio of the first solvent to the light oil of (1-6):1.

[0059] It should be noted that, in one embodiment, based on the weight of the first saturated fraction, the content of saturated hydrocarbons in the first saturated fraction obtained by the first separation is 85-98% by weight. The above-mentioned first solvent is selected, and the first extraction separation is carried out under the above-mentioned conditions. The first saturated fraction obtained is used together with the second saturated fraction and the third saturated fraction as catalytic cracking raw materials for catalytic cracking reaction, which is conducive to better preparation of high value-added products.

[0060] According to a specific embodiment of the process method of the first aspect of the present invention, the second separation in step (3) comprises: contacting the intermediate oil with an ionic liquid or a second solvent for a second extraction separation;

[0061] The thermal stability of the ionic liquid is higher than 250°C;

[0062] Wherein, the ionic liquid comprises cations and anions; the cations are selected from alkyl-substituted imidazoles and / or pyridines; the anions are selected from at least one of hexafluorophosphate, tetrafluoroborate and bis(trifluoromethylsulfonyl)imide;

[0063] The second solvent is selected from one or more combinations of furfural, dimethyl sulfoxide, N,N-dimethylformamide, N,N-diethylformamide and morpholine;

[0064] The conditions for the second extraction separation include: a temperature of 15-120° C., a pressure of 0.1-0.5 MPa, and a weight ratio of the ionic liquid to the intermediate oil, or a weight ratio of the second solvent to the intermediate oil, each independently being (1-15):1.

[0065] It should be noted that, in one embodiment, based on the weight of the second saturated fraction, the content of saturated hydrocarbons in the second saturated fraction obtained by the second separation is 75-90% by weight. The above-mentioned second solvent or ionic liquid is selected, and the second extraction separation is carried out under the above-mentioned conditions. The obtained second saturated fraction is used together with the first saturated fraction and the third saturated fraction as catalytic cracking raw materials for catalytic cracking reaction, which is conducive to further improving the yield of catalytic cracking high value-added products.

[0066] According to a specific embodiment of the process method described in the first aspect of the present invention, the third separation in step (4) comprises: contacting the heavy oil with a third solvent to perform supercritical extraction separation;

[0067] Wherein, the third solvent is selected from low carbon alkanes; the low carbon alkanes are selected from one or a mixture of ethane, propane, propylene, n-butane, isobutane, n-pentane, isopentane, hexane, heptane and octane;

[0068] The conditions for the supercritical extraction separation include: a temperature of 50-100° C., a pressure of 6-20 MPa, and a weight ratio of the third solvent to the heavy oil of (2-5):1.

[0069] It should be noted that, in one embodiment, based on the weight of the third saturated fraction, the content of saturated hydrocarbons in the third saturated fraction obtained by the third separation is greater than 45% by weight. The third solvent is selected, and supercritical extraction separation is performed under the above conditions. The third saturated fraction obtained is used together with the first saturated fraction and the second saturated fraction obtained in step (2) and step (3) as catalytic cracking raw materials for the catalytic cracking reaction in step (5), which can better convert and generate high value-added products.

[0070] According to a specific implementation of the process method described in the first aspect of the present invention, the process method further includes the following steps:

[0071] Using the first unsaturated fraction from step (2) as a raw material to produce aromatic hydrocarbons; and / or,

[0072] The second unsaturated fraction from step (3) is used as a raw material for producing high-octane gasoline and / or aromatics; and / or,

[0073] The third unsaturated fraction from step (4) is used as a raw material for producing needle coke and / or road asphalt; and / or,

[0074] The cracked gas from step (5) is separated to obtain ethylene, propylene, butene and remaining components.

[0075] It should be noted that the method for separating the cracked gas obtained in step (5) to obtain the target products such as ethylene, propylene and butene can adopt conventional separation methods in the art, or methods well known to those skilled in the art. In the process method of the present application, the saturated fraction obtained by separation in steps (2)-(4) can be subjected to the catalytic cracking reaction in step (5) to obtain high value-added products with high yield; the unsaturated fraction rich in aromatics obtained in different distillation ranges from steps (2)-(4) can be used as a raw material for producing aromatics or high-octane gasoline, needle coke or asphalt according to its composition characteristics. In this way, the saturated fraction and unsaturated fraction in crude oil can be well converted or utilized, and the crude oil utilization rate is high.

[0076] According to another preferred embodiment of the process method of the first aspect of the present invention, the light hydrocarbons of the difficult-to-convert components include a gaseous hydrocarbon product rich in C4 fraction, preferably including butenes obtained by separation of the cracked gas;

[0077] The light distillate oil of the difficult-to-convert component includes self-produced light distillate oil with a final boiling point of less than 280-360°C and optionally one or more of the following fractions: straight-run naphtha, straight-run kerosene, straight-run diesel produced by other primary processing units, topped oil, raffinate oil, hydrocracking light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline and hydrogenated diesel produced by other secondary processing units; and / or, the light distillate oil of the difficult-to-convert component preferably includes the cracking light gasoline obtained from step (5); the weight proportion of butene as the difficult-to-convert component in the catalytic cracking feedstock is 5-20%; the weight proportion of cracking light gasoline as the difficult-to-convert component in the catalytic cracking feedstock is 5-20%.

[0078] It should be noted that, in this preferred embodiment, the catalytic cracking raw material in step (5) includes not only the first saturated fraction, the second saturated fraction, and the third saturated fraction, but also hard-to-convert components, which may include butene obtained by separation of cracked gas and / or the cracked light gasoline obtained by separation of oil and gas; in the catalytic cracking raw material, the weight proportion of the hard-to-convert components may be 8%, 10%, 15%, etc. After years of research and development experiments, the inventors of the present application have found that using the hard-to-convert components together with the above three saturated components as catalytic cracking raw materials for the catalytic cracking reaction of step (5) is conducive to better converting the catalytic cracking raw materials into high-value products such as light olefins (ethylene, propylene, butene), light aromatics BTX (benzene, toluene and xylene), and can further improve the yield of high value-added products.

[0079] It should be noted that the light hydrocarbons of the difficult-to-convert components may include gaseous hydrocarbon products rich in C4 fractions produced by the process of the present application and gaseous hydrocarbons rich in C4 fractions produced by other device processes, preferably C4 fractions or butenes produced by the process of the present application. The light distillate oil of the difficult-to-convert components may include light distillate oil with a final boiling point of less than 280-360°C produced by the process of the present application, or a mixed oil of one or more of the above-mentioned straight-run naphtha, straight-run kerosene, etc. introduced by other external processes or devices.

[0080] It should be noted that, in one embodiment, the light hydrocarbon in the difficult-to-convert component is a C4 component, which refers to a low molecular hydrocarbon compound that exists in the form of gas at room temperature and pressure and has a C4 fraction as the main component, including alkanes, olefins and alkynes with 4 carbon atoms in the molecule. It includes a gaseous hydrocarbon product rich in C4 fraction produced by the process of the present invention, and may also include gaseous hydrocarbons rich in C4 fraction produced by other processes, among which the C4 fraction produced by the process of the present invention is 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 preferably above 70% by weight.

[0081] It should be noted that, in one embodiment, the light distillate oil in the difficult-to-convert components is a light distillate oil with a final distillation point of less than 280-350°C, including the light distillate oil with a final distillation point of less than 280-350°C produced by the process method of the present invention, and may also include a mixture of one or more of primary processed straight-run naphtha, straight-run kerosene, and straight-run diesel; a mixed oil of one or more of secondary processed top oil, raffinate oil, hydrocracking light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline, and hydrogenated diesel.

[0082] According to a specific implementation of the process method described in the first aspect of the present invention, the process method further includes the following steps:

[0083] subjecting the second unsaturated fraction from step (3) to a hydrogenation reaction to obtain a hydrogenated component;

[0084] The catalytic cracking feedstock in step (5) also includes the hydrogenation component;

[0085] The weight proportion of the hydrogenation component in the catalytic cracking feedstock is 0.1-10%.

[0086] It should be noted that, as a preferred embodiment, the second unsaturated fraction from step (3) is subjected to a hydrogenation treatment reaction under the action of hydrogen and a hydrogenation catalyst to obtain a hydrogenated component, i.e., the second unsaturated fraction after hydrogenation. The hydrogenated component can be used together with the first saturated fraction, the second saturated fraction, and the third saturated fraction as a catalytic cracking raw material for the catalytic cracking reaction of step (5), or the hydrogenated component can be used as a raw material for producing a high-octane gasoline component or an aromatic component. In this preferred embodiment, in step (5), the catalytic cracking raw material includes the first saturated fraction, the second saturated fraction, the third saturated fraction, butenes obtained by separation of gas products, and the hydrogenated component obtained by hydrogenation reaction of the second unsaturated fraction obtained from step (3). The catalytic cracking raw material composed of the above can better prepare high-value products through catalytic cracking reaction, thereby further improving the yield of high-value products.

[0087] It should be noted that, in this embodiment, the conditions for the hydrogenation reaction of the second unsaturated fraction obtained in step (3) include a hydrogen partial pressure of 10.0-25.0 MPa, a reaction temperature of 330-450°C, and a volume space velocity of 0.1-2.0 h -1 , Hydrogen oil volume ratio 1000-2000Nm 3 / m 3 The active metal component in the hydrogenation catalyst is selected from metals of Group VIB and / or non-precious metals of Group VIII, and the carrier is selected from any one or more of alumina, silicon dioxide, and amorphous silicon aluminum. The metal of Group VIB is molybdenum and / or tungsten, and the non-precious metal of Group VIII is nickel and / or cobalt. The active metal component is preferably a combination of one or more of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum.

[0088] According to a specific embodiment of the process method described in the first aspect of the present invention, the conditions for the catalytic cracking reaction in step (5) include:

[0089] The catalytic cracking raw material is mixed with water vapor and then fed, wherein the reaction temperature is 510-650° C., the reaction time is 1-20 seconds, the weight ratio of the catalyst to the catalytic cracking raw material is (3-50):1, and the weight ratio of the water vapor to the catalytic cracking raw material is (0.03-0.8):1; and / or,

[0090] The catalyst comprises the following components, based on the dry weight of the components and the catalyst:

[0091] 1-50 wt% zeolite, 5-99 wt% inorganic oxide, and 0-70 wt% clay;

[0092] Preferably 5-45 wt% zeolite, 10-80 wt% inorganic oxide, and 5-60 wt% clay;

[0093] More preferably, it is 10-40 wt% of zeolite, 20-70 wt% of inorganic oxide, and 10-50 wt% of clay.

[0094] It should be noted that in the process method of the present application, by controlling the conditions of the catalytic cracking reaction in step (5) as described above, the catalytic cracking raw materials can be better reacted under the catalysis of the above-mentioned catalyst to form high-value products such as light olefins (ethylene, propylene, butene), light aromatics BTX (benzene, toluene and xylene), etc., which can further improve the yield of high value-added products.

[0095] It should be noted that, in one embodiment, the zeolite includes a medium-pore zeolite and an optional large-pore zeolite, wherein the medium-pore zeolite is selected from ZSM series zeolites, ZRP zeolites, and any combination thereof; the large-pore zeolite is selected from rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite and high-silicon Y-type zeolite, and any combination thereof.

[0096] In one embodiment, the medium pore zeolite accounts for 10-90 wt %, preferably 50-80 wt %, of the total weight of the zeolite on a dry basis.

[0097] In the present application, the medium-pore zeolite and large-pore zeolite follow the conventional definition in the art, that is, the average pore diameter of the medium-pore zeolite is about 0.5-0.6 nm, and the average pore diameter of the large-pore zeolite is about 0.7-1.0 nm.

[0098] As an example, the large-pore zeolite can 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 silicon Y type zeolite. The medium-pore zeolite can be selected from zeolites with MFI structure, such as ZSM series zeolites and / or ZRP zeolites. Optionally, the above-mentioned medium-pore zeolites can also 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 U.S. Patent No. 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 of similar structure. A more detailed description of ZSM-5 can be found in U.S. Patent No. 3,702,886A.

[0099] It should be noted that the inorganic oxide as a binder is preferably silicon dioxide (SiO 2 ) and / or aluminum oxide (Al 2 O 3 The clay used as the matrix (ie, carrier) is preferably kaolin and / or halloysite.

[0100] In a second aspect, the present invention relates to a system for producing high value-added products from crude oil, such as Figure 1 As shown, the system includes a distillation unit 100, a first separation unit 201, a second separation unit 202, a third separation unit 203 and a catalytic cracking reaction unit 400;

[0101] The distillation unit 100 is provided with a crude oil inlet 101, a light distillate oil outlet 201a, a middle distillate oil outlet 202a and a heavy distillate oil outlet 203a;

[0102] The light fraction oil outlet 201a of the distillation unit 100 is connected to the inlet of the material to be separated of the first separation unit 201, and the first separation unit 201 is also provided with a first saturated fraction outlet 201b and a first unsaturated fraction outlet 201c;

[0103] The middle distillate oil outlet 202a of the distillation unit 100 is connected to the inlet of the material to be separated of the second separation unit 202, and the second separation unit 202 is also provided with a second saturated fraction outlet 202b and a second unsaturated fraction outlet 202c;

[0104] The heavy fraction oil outlet 203a of the distillation unit 100 is connected to the inlet of the material to be separated of the third separation unit 203, and the third separation unit 203 is also provided with a third saturated fraction outlet 203b and a third unsaturated fraction outlet 203c;

[0105] The first saturated outlet 201b, the second saturated outlet 202b and the third saturated outlet 203b are respectively connected to the catalytic cracking feedstock inlet of the catalytic cracking reaction unit 400; the catalytic cracking reaction unit 400 is also provided with 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.

[0106] It should be noted that the process method described in the first aspect of the present invention can be based on but 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 not limited to the process method described in the first aspect of the present invention.

[0107] It should be noted that in the system of the present application, crude oil enters the distillation unit 100 through the crude oil inlet 101, and is cut into light distillate oil, middle distillate oil and heavy distillate oil through distillation. The three oil products obtained by cutting flow out of the distillation unit 100 through the light distillate oil outlet 201a, the middle distillate oil outlet 202a and the heavy distillate oil outlet 203a, respectively, and then enter the first separation unit 201, the second separation unit 202 and the third separation unit 203, respectively. The light distillate oil, the middle distillate oil and the heavy distillate oil are separated in the three separation units. Specifically, the light distillate oil is separated into the first saturated fraction and the first unsaturated fraction by the first separation unit 201, the middle distillate oil is separated into the second saturated fraction and the second unsaturated fraction by the second separation unit 202, and the heavy distillate oil is separated into the third saturated fraction and the third unsaturated fraction by the third separation unit 203. The first saturated fraction flows out through the first saturated fraction outlet 201b and then enters the catalytic cracking reaction unit 400 through the catalytic cracking raw material inlet, the second saturated fraction flows out through the second saturated fraction outlet 202b and then enters the catalytic cracking reaction unit 400 through the catalytic cracking raw material inlet, and the third saturated fraction flows out through the third saturated fraction outlet 203b and then enters the catalytic cracking reaction unit 400 through the catalytic cracking raw material inlet; the three saturated fractions are used as catalytic cracking raw materials in the catalytic cracking reaction unit 400 and contact with the catalyst to undergo catalytic cracking reaction at high temperature, and are separated in turn through the oil agent separation equipment and the oil-gas separation equipment to obtain cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil, and the above-mentioned products flow out through the cracking gas outlet 401, the cracking light gasoline outlet 402, the cracking heavy gasoline outlet 403, the cracking diesel outlet 404 and the cracking heavy oil outlet 405 respectively.

[0108] It should be noted that the system of the present application first distills and cuts the crude oil through the distillation unit 100, and then separates the three types of oil products obtained by the division through three separation units. The three saturated fractions obtained after separation are used as catalytic cracking raw materials for catalytic cracking in the catalytic cracking reaction unit 400, so that the crude oil can be better converted into high-value products such as light olefins (ethylene, propylene, butene), light aromatics BTX (benzene, toluene and xylene).

[0109] It should be noted that in the system for producing high value-added products from crude oil of the present invention, equipment such as oil agent separation equipment and reaction product separation equipment may also be provided. The oil agent separation equipment and reaction product separation equipment are both well known to those skilled in the art. For example, the oil agent separation equipment may include a cyclone separator, a settler and a stripper, etc., while the reaction product separation equipment may be a distillation tower, etc.

[0110] According to a specific embodiment of the system of the second aspect of the present invention, the system is further provided with an aromatics production unit, and the first unsaturated branch outlet 201c is connected to the raw material inlet of the aromatics production unit; and / or,

[0111] The system is further provided with a high-octane gasoline production unit, and the second unsaturated outlet 202c is connected to the raw material inlet of the high-octane gasoline production unit and / or the raw material inlet of the aromatics production unit; and / or,

[0112] The system is further provided with a needle coke production unit and a road asphalt production unit, and the third unsaturated outlet 203c is connected to the raw material inlet of the needle coke production unit and / or the raw material inlet of the road asphalt production unit; and / or,

[0113] The system further comprises a gas separation unit, the cracked gas outlet 401 of the catalytic cracking reaction unit 400 is connected to the gas inlet to be separated of the gas separation unit, and the gas separation unit is further provided with an ethylene outlet, a propylene outlet, a butene outlet and an outlet for remaining components.

[0114] It should be noted that the light distillate oil is separated into the first saturated fraction and the first unsaturated fraction by the first separation unit 201, and the obtained first unsaturated fraction can flow out through the first unsaturated fraction outlet 201c and enter the aromatics production unit as a raw material to produce aromatics. The middle distillate oil is separated into the second saturated fraction and the second unsaturated fraction by the second separation unit 202, and the obtained second unsaturated fraction can flow out through the second unsaturated fraction outlet 202c and enter the high-octane gasoline production unit as a raw material to produce high-octane gasoline, or can enter the aromatics production unit as a raw material to produce aromatics. The heavy distillate oil is separated into the third saturated fraction and the third unsaturated fraction by the third separation unit 203, and the obtained third unsaturated fraction flows out through the third unsaturated fraction outlet 203c and enters the needle coke production unit as a raw material to produce needle coke, or enters the road asphalt production unit as a raw material to produce road asphalt.

[0115] It should be noted that the cracked gas flowing out through the cracked gas outlet 401 is separated into ethylene, propylene, butene and remaining components by a gas separation unit. The system of the present application can make good use of various components.

[0116] According to another specific embodiment of the system according to the second aspect of the present invention, the catalytic cracking reaction unit 400 is further provided with a difficult-to-convert component inlet 406, and the difficult-to-convert component inlet 406 is connected to the cracking light gasoline outlet 402 and / or the butene outlet of the gas separation unit.

[0117] It should be noted that, as a preferred embodiment, the cracked light gasoline flows out from the cracked light gasoline outlet 402 and enters the catalytic cracking reaction unit 400 through the difficult-to-convert component inlet 406 as a catalytic cracking feedstock for catalytic cracking reaction, and the butene separated by the gas separation unit flows out from the butene outlet and enters the catalytic cracking reaction unit 400 through the difficult-to-convert component inlet 406 as a catalytic cracking feedstock for catalytic cracking reaction. Using the above-mentioned butene and / or cracked light gasoline as part of the catalytic cracking feedstock can make the catalytic cracking reaction proceed better and can further improve the yield of high-value products.

[0118] It should be noted that, as a variant implementation, the difficult-to-convert component inlet 406 can be connected to the gaseous hydrocarbon outlet of the C4 fraction rich in other external devices, or to the light distillate oil outlet with a final boiling point less than 280-360°C of other external devices, specifically, it can be connected to one or more of the straight-run naphtha outlet, straight-run kerosene outlet, and straight-run diesel outlet of other primary processing devices, or to one or more of the top oil outlet, raffinate oil outlet, hydrocracking light naphtha outlet, pentane oil outlet, coker gasoline outlet, Fischer-Tropsch synthetic oil outlet, catalytic cracking light gasoline outlet, hydrogenated gasoline outlet, and hydrogenated diesel outlet of other secondary processing devices.

[0119] It should be noted that the difficult-to-convert component inlet 406 may be one, two or more. In one embodiment, when there is one difficult-to-convert component inlet 406, light hydrocarbons and light distillate oil as difficult-to-convert components may enter the catalytic cracking reaction unit through the same difficult-to-convert component inlet 406; in another preferred embodiment, the number of difficult-to-convert component inlets 406 is two or more, and light hydrocarbons and light distillate oil as difficult-to-convert components enter the catalytic cracking reactor through different difficult-to-convert component inlets 406, respectively. Specifically, light hydrocarbons are introduced into the catalytic cracking reactor at one or more difficult-to-convert component inlets 406 downstream of the difficult-to-convert component inlet 406 (introduction position) for introducing light distillate oil, which is conducive to obtaining high-value products with a higher yield.

[0120] It should be noted that, in one embodiment, the catalytic cracking reactor is provided with one or more, for example, one, two or more difficult-to-convert component inlets, and the one or more difficult-to-convert component inlets can be independently arranged at the lower part of the catalytic cracking reactor. Further preferably, the difficult-to-convert component inlets are independently arranged at the middle and upstream of the catalytic cracking reactor.

[0121] According to another specific embodiment of the system described in the second aspect of the present invention, the system is further provided with a hydrogenation reaction unit 300, the second unsaturated branch outlet 202c is connected to the hydrogenation feedstock inlet of the hydrogenation reaction unit 300, and the hydrogenation product outlet 301 of the hydrogenation reaction unit 300 is connected to the catalytic cracking feedstock inlet of the catalytic cracking reaction unit 400.

[0122] As a preferred embodiment, the middle distillate oil is separated into a second saturated fraction and a second unsaturated fraction by the second separation unit 202, and the obtained second unsaturated fraction enters the hydrogenation reaction unit 300, and undergoes a hydrogenation reaction in the presence of hydrogen and a hydrogenation catalyst, and the second unsaturated fraction hydrogenated product flows out through the hydrogenation product outlet 301 and enters the catalytic cracking reaction unit 400 as a catalytic cracking feedstock for catalytic cracking reaction. In this preferred embodiment, the second unsaturated fraction hydrogenated product and the three saturated fractions (butene obtained by gas separation may also be included) are used as catalytic cracking feedstocks for catalytic cracking reaction, which can further improve the yield of high-value products.

[0123] According to a specific embodiment of the system of the second aspect of the present invention, the first separation unit 201 is an extraction separation unit, the second separation unit 202 is an extraction separation unit, and the third separation unit 203 is a supercritical extraction separation unit;

[0124] The catalytic cracking reaction unit 400 is selected from one or a combination of reactors selected from fluidized bed, turbulent bed, fast bed and dilute phase transport bed; the reactor is selected from one or a series combination of constant linear velocity reactor, constant diameter reactor, variable diameter reactor, upward transport line reactor and downward transport line reactor.

[0125] It should be noted that in the system of the present application, an extraction separation unit and a supercritical extraction separation unit are used in combination, and the catalytic cracking reaction unit (reactor) is selected from the above-mentioned reactor, so that the separation process and the catalytic cracking reaction process can operate better to improve the yield of high-value products of the system.

[0126] It should be noted that, in order to allow the crude oil to react fully and according to different quality requirements of the target product, the reaction zones of the catalytic cracking reaction unit can be 2-8, preferably 2-3. The gas velocity of the turbulent bed and fast bed reactor is 0.1 m / s-2 m / s, and the gas velocity of the dilute phase transport bed is 2 m / s-20 m / s.

[0127] Figure 1 A preferred implementation of the system for producing high value-added products from crude oil of the present application is provided.

[0128] like Figure 1 As shown, crude oil enters the distillation unit 100 through the crude oil inlet 101 and is separated into light distillate oil, middle distillate oil and heavy distillate oil under the action of heat;

[0129] The separated light distillate oil flows out through the light distillate oil outlet 201a and enters the first separation unit 201, contacts with the extraction solvent and separates the components to obtain a first saturated fraction and a first unsaturated fraction. The first saturated fraction flows out through the first saturated fraction outlet 201b and enters the catalytic cracking reaction unit 400; the first unsaturated fraction flows out through the first unsaturated fraction outlet 201c and is used as a raw material for aromatic production.

[0130] The separated middle distillate flows out through the middle distillate outlet 202a and enters the second separation unit 202, contacts with the extraction solvent and separates the components to obtain a second saturated fraction and a second unsaturated fraction. The second saturated fraction flows out through the second saturated fraction outlet 202b and enters the catalytic cracking reaction unit 400; the second unsaturated fraction flows out through the second unsaturated fraction outlet 202c and is used as a raw material for producing a high-octane gasoline component or an aromatic component. Optionally, the second unsaturated fraction flows out through the second unsaturated fraction outlet 202c and is sent to the hydrogenation reaction unit 300, where it is hydrogenated under the action of hydrogen and a hydrogenation catalyst. The hydrogenated second unsaturated fraction flows out through the hydrogenation product outlet 301 and is sent to the catalytic cracking reaction unit 400.

[0131] The separated heavy distillate oil flows out through the heavy distillate oil outlet 203a and enters the third separation unit 203, contacts with the extraction solvent and separates the components to obtain a third saturated fraction and a third unsaturated fraction. The third saturated fraction flows out through the third saturated fraction outlet 203b and is sent to the catalytic cracking reaction unit 400; the third unsaturated fraction is sent out of the device through the third unsaturated fraction outlet 203c and is used as a raw material for the production of needle coke or road asphalt.

[0132] The first saturated fraction from the first saturated fraction outlet 201b, the second saturated fraction from the second saturated fraction outlet 202b and the third saturated fraction from the third saturated fraction outlet 203b, and the optional difficult-to-convert components from the difficult-to-convert components inlet 406 enter the catalytic cracking reaction unit 400, and a catalytic cracking reaction occurs under the action of heat and a catalytic cracking catalyst. The reaction products are separated to obtain cracking gas (flowing out of the cracking gas outlet 401), cracking light gasoline (flowing out of the cracking light gasoline outlet 402), cracking heavy gasoline (flowing out of the cracking heavy gasoline outlet 403), cracking diesel (flowing out of the cracking diesel outlet 404) and cracking heavy oil (flowing out of the cracking heavy oil outlet 405). The cracking gas can be further separated to obtain ethylene, propylene, butene and other products.

[0133] The present invention is further described in detail by way of examples below, but the present invention is not limited thereto. In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0134] The feedstock oil used in the following examples and comparative examples is Kuwait crude oil, and its properties are shown in Table 1. The catalyst used in the catalytic cracking unit is a commercial catalytic cracking catalyst purchased from the Catalyst Branch of Sinopec, with a trade name of DMMC-2. The trade name of the hydrotreating catalyst is RN-32L.

[0135] Table 1 Properties of crude oil used

[0136]

[0137]

[0138] The yield of high value-added products refers to the total yield of light olefins (ethylene, propylene, butene), light aromatics BTX (benzene, toluene and xylene), aromatic components (first unsaturated fraction), high-octane gasoline components (second unsaturated fraction), and needle coke or road asphalt components (third unsaturated fraction). The yield of a certain product can refer to the weight percentage of the product in crude oil.

[0139] Example 1

[0140] The Kuwait crude oil in Table 1 is subjected to actual boiling point distillation to obtain light distillate oil, middle distillate oil and heavy distillate oil, wherein the cut point between light distillate oil and middle distillate oil is 200°C, and the cut point between middle distillate oil and heavy distillate oil is 300°C. The light distillate oil is subjected to extraction separation in the first separation unit using cyclopentane as solvent to obtain the first saturated fraction and the first unsaturated fraction, wherein the yield of the first saturated fraction is 90.6%, the mass fraction of saturated hydrocarbons in the first saturated fraction is 95.55%, and the mass fraction of aromatic hydrocarbons in the first unsaturated fraction is 95.86%, which is a high-quality raw material for producing aromatic components.

[0141] The middle distillate oil is extracted and separated in the second separation unit by using ionic liquid as solvent, the cation is dialkyl substituted imidazolium cation, the alkyl groups are methyl and hexyl respectively, and the anion is hexafluorophosphate anion to obtain the second saturated fraction and the second unsaturated fraction, wherein the yield of the second saturated fraction is 83%, the mass fraction of saturated hydrocarbons in the second saturated fraction is 87.4%, and the mass fraction of aromatic hydrocarbons in the second unsaturated fraction is 92.4%, which is a high-quality raw material for producing high-octane gasoline components or aromatic components.

[0142] The heavy distillate oil is sent to the third separation unit using propane as the solvent, and is separated by supercritical extraction to obtain a third saturated fraction and a third unsaturated fraction, wherein the yield of the third saturated fraction is 76.2%, the mass fraction of saturated hydrocarbons in the third saturated fraction is 52.4%, the heavy metal removal rate is above 96%, and the third unsaturated fraction can be used as a raw material for road asphalt.

[0143] A fluidized bed reactor device was used to conduct a catalytic cracking reaction test of saturated fractions of different distillation ranges. Before the test, the catalyst was first loaded into the reactor, and the reactor was heated to the reaction temperature while the catalyst was kept in a fluidized state. The catalytic cracking raw materials including the first saturated fraction, the second saturated fraction, the third saturated fraction and the difficult-to-convert component light gasoline (the cracked light gasoline obtained from the separation of liquid products) were allowed to enter the fluidized bed reactor device. After preheating, the raw materials were mixed with high-temperature water vapor and entered the bottom of the fluidized reaction bed through the feed nozzle. The difficult-to-convert component butene (from the separation of gas products) entered the bottom of the fluidized bed reactor from the gas feed pipeline through the feed nozzle. All the reaction raw materials reacted on the hot catalyst. After the reaction, water vapor was introduced for stripping, and the reaction oil and gas entered the multi-stage condensation separation system for separation to obtain cracking gas products and liquid products. The gas products and liquid products were measured to obtain the yield. The gas products were separated to obtain ethylene, propylene, butene and remaining components. After the reaction was completed, the reactor was automatically heated to the regeneration temperature, and oxygen was introduced into the reactor to burn and regenerate the catalyst to be regenerated. The regenerated flue gas was measured by an infrared analyzer to obtain real-time CO 2The concentration is calculated based on the flue gas flow integral. The gas products are collected and then distributed using offline chromatography. The liquid products are analyzed using simulated distillation chromatography to obtain the mass fractions of pyrolysis gasoline (pyrolysis light gasoline and pyrolysis heavy gasoline), pyrolysis diesel and pyrolysis heavy oil.

[0144] The reaction conditions and product yields of different units are listed in Tables 2 and 3. As can be seen from Table 3, the ethylene yield of this embodiment reaches 12.80% by weight, the propylene yield reaches 26.01% by weight, the high value-added product yield is as high as 70.79% by weight, and the coke yield is 9.10% by weight.

[0145] Example 2

[0146] The Kuwait crude oil in Table 1 is subjected to actual boiling point distillation to obtain light distillate oil, middle distillate oil and heavy distillate oil, wherein the cut point between light distillate oil and middle distillate oil is 200°C, and the cut point between middle distillate oil and heavy distillate oil is 300°C. The light distillate oil is subjected to extraction separation in the first separation unit using cyclopentane as solvent to obtain the first saturated fraction and the first unsaturated fraction, wherein the yield of the first saturated fraction is 90.6%, the mass fraction of saturated hydrocarbons in the first saturated fraction is 95.55%, and the mass fraction of aromatic hydrocarbons in the first unsaturated fraction is 95.86%, which is a high-quality raw material for producing aromatic components.

[0147] The middle distillate oil is extracted and separated in the second separation unit by using ionic liquid as solvent, the cation is dialkyl substituted imidazolium cation, the alkyl groups are methyl and hexyl respectively, and the anion is hexafluorophosphate anion to obtain the second saturated fraction and the second unsaturated fraction, wherein the yield of the second saturated fraction is 83%, the mass fraction of saturated hydrocarbons in the second saturated fraction is 87.4%, and the mass fraction of aromatic hydrocarbons in the second unsaturated fraction is 92.4%, which is a high-quality raw material for producing high-octane gasoline components or aromatic components.

[0148] The second unsaturated fraction is sent to the hydrogenation unit, and after being hydrogenated and upgraded, it is sent back to the fluidized bed reactor of the catalytic cracking unit to be further converted into high-value products.

[0149] The heavy distillate oil is sent to the third separation unit using propane as the solvent, and is separated by supercritical extraction to obtain a third saturated fraction and a third unsaturated fraction, wherein the yield of the third saturated fraction is 76.2%, the mass fraction of saturated hydrocarbons in the third saturated fraction is 52.4%, the heavy metal removal rate is above 96%, and the third unsaturated fraction can be used as a raw material for road asphalt.

[0150] A fluidized bed reactor device is used to conduct a catalytic cracking reaction test of saturated fractions of different distillation ranges. Before the test, the catalyst is first loaded into the reactor, and the reactor is heated to the reaction temperature while the catalyst is kept in a fluidized state. The catalytic cracking raw materials including the first saturated fraction, the second saturated fraction, the hydrogenated second unsaturated fraction, the third saturated fraction and the difficult-to-convert component light gasoline (the cracked light gasoline obtained from the separation of liquid products) are allowed to enter the fluidized bed reactor device. The raw materials are mixed with high-temperature water vapor after preheating and enter the bottom of the fluidized reaction bed through the feed nozzle. The difficult-to-convert component butene (from the separation of gas products) enters the bottom of the fluidized bed reactor from the gas feed pipeline through the feed nozzle. All reaction raw materials react on the hot catalyst. After the reaction, water vapor is introduced for stripping, and the reaction oil and gas enter the multi-stage condensation separation system for separation to obtain cracking gas products and liquid products. The yields of the gas products and liquid products are measured. The gas products are separated to obtain ethylene, propylene, butene and remaining components. After the reaction is completed, the reactor is automatically heated to the regeneration temperature, and oxygen is introduced into the reactor to burn and regenerate the catalyst. The real-time CO 2 The concentration is calculated based on the flue gas flow integral. The gas products are collected and then distributed using offline chromatography. The liquid products are analyzed using simulated distillation chromatography to obtain the mass fractions of pyrolysis gasoline (pyrolysis light gasoline and pyrolysis heavy gasoline), pyrolysis diesel and pyrolysis heavy oil.

[0151] The reaction conditions and product yields of different units are listed in Tables 2 and 3. As can be seen from Table 3, the ethylene yield of this embodiment reaches 12.85% by weight, the propylene yield reaches 26.35% by weight, the high value-added product yield is as high as 70.67% by weight, and the coke yield is 9.16% by weight.

[0152] Comparative Example 1

[0153] This comparative example is a test of direct catalytic cracking of crude oil. Using the Kuwait crude oil and DMMC-2 catalyst shown in Table 1, a fixed fluidized bed reactor test device was used to carry out a crude oil catalytic cracking reaction test. Before the test, the catalyst was first loaded into the reactor, and the reactor was heated to the reaction temperature while the catalyst was kept in a fluidized state. After preheating, the crude oil was mixed with high-temperature water vapor, entered the bottom of the fluidized reactor bed through a feed nozzle, and reacted on the hot catalyst. After the reaction, water vapor was introduced for stripping, and the reaction oil and gas entered a multi-stage condensation separation system for separation to obtain cracking gas products and liquid products. The gas products and liquid products were measured to obtain yields. After the reaction is completed, the reactor automatically heats up to the regeneration temperature, and at the same time, oxygen is introduced into the reactor to regenerate the catalyst to be regenerated by charring. The regenerated flue gas is measured by an infrared analyzer to obtain real-time CO 2The concentration is calculated based on the flue gas flow integral. The gas products are collected and then distributed using offline chromatography. The liquid products are analyzed using simulated distillation chromatography to obtain the mass fractions of pyrolysis gasoline, pyrolysis diesel, and pyrolysis heavy oil. The reaction conditions and product distribution are listed in Tables 2 and 3.

[0154] From the results in Table 3, it can be seen that the ethylene yield of this comparative example is only 5.56% by weight, the propylene yield is only 15.85% by weight, the high value-added product yield is 39.04% by weight, and the coke yield is 13.12% by weight.

[0155] Comparative Example 2

[0156] The Kuwait crude oil is separated into light distillate oil, middle distillate oil and heavy distillate oil by actual boiling point distillation, wherein the cut point between the light distillate oil and the middle distillate oil is 200°C, and the cut point between the middle distillate oil and the heavy distillate oil is 300°C.

[0157] A fluidized bed reactor test device was used to conduct catalytic cracking reaction tests of crude oil distillates with different distillation ranges. Before the test, the catalyst was first loaded into the reactor, and the reactor was heated to the reaction temperature while the catalyst was kept in a fluidized state. Crude oil distillates with different distillation ranges were mixed with high-temperature water vapor in the order of light distillate, middle distillate and heavy distillate, and preheated, and entered the bottom of the fluidized reactor bed through a feed nozzle to react on the hot catalyst. After the reaction, water vapor was introduced for stripping, and the reaction oil and gas entered a multi-stage condensation separation system for separation to obtain cracking gas products and liquid products. The yields of the gas products and liquid products were measured. After the reaction was completed, the reactor automatically heated up to the regeneration temperature, and oxygen was introduced into the reactor to regenerate the catalyst to be regenerated by burning. The regenerated flue gas was measured by an infrared analyzer to obtain real-time CO 2 The concentration is calculated based on the flue gas flow integral. The gaseous products are collected and then distributed by offline chromatography. The liquid products are analyzed by simulated distillation chromatography to obtain the mass fractions of pyrolysis gasoline, pyrolysis diesel and pyrolysis heavy oil. The reaction conditions and product distribution are listed in Table 2 and Table 3.

[0158] From the results in Table 3, it can be seen that the ethylene yield of this comparative example is only 7.61% by weight, the propylene yield is only 17.30% by weight, the high value-added product yield is 43.76%, and the coke yield is 11.26% by weight.

[0159] Table 2 Reaction conditions of Examples 1-2 and Comparative Examples 1-2

[0160]

[0161]

[0162] The amount of water vapor used in Table 2, in weight %, represents the proportion of water vapor in the total weight of the catalytic cracking feedstock.

[0163] The weight ratio of catalyst to catalytic cracking feedstock, the proportion of difficult-to-convert components in the catalytic cracking feedstock and the proportion of the second unsaturated components in the catalytic cracking feedstock are such that the amount of catalytic cracking feedstock does not include difficult-to-convert components (butene and cracked light gasoline).

[0164] Table 3 Comparison of reaction results of Example 1-2 and Comparative Example 1-2

[0165]

[0166] In Example 2, based on the weight of crude oil, the yield of the second unsaturated fraction is 1.77% by weight. After hydrogenation in the hydrogenation unit, the fraction is sent to the catalytic cracking unit for cracking reaction to convert into high value-added products. Therefore, the yield of high value-added products in Example 2 is not included in the weight of the second unsaturated fraction.

[0167] It can be seen from the results of the above embodiments and comparative examples that when the catalytic cracking method and system of the present application are used for catalytic cracking of crude oil, the yields of ethylene and propylene are significantly improved, and the yield of high value-added products is high, that is, the utilization rate of crude oil atoms is high.

[0168] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of the present application. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present application.

[0169] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect" and "connect" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0170] The present application has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, various replacements and improvements may be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A process for producing high value-added products from crude oil, characterized in that: The process comprises the following steps: (1) subjecting crude oil to distillation and cutting to obtain light oil, intermediate oil and heavy oil; wherein the cutting point between the light oil and the intermediate oil is 160-220° C., and the cutting point between the intermediate oil and the heavy oil is 260-320° C.; (2) subjecting the light oil to a first separation to obtain a first saturated fraction and a first unsaturated fraction; (3) subjecting the intermediate oil to a second separation to obtain a second saturated fraction and a second unsaturated fraction; (4) subjecting the heavy oil to a third separation to obtain a third saturated fraction and a third unsaturated fraction; (5) contacting the catalytic cracking feedstock with the catalyst to perform a catalytic cracking reaction, and obtaining cracking gas, cracking light gasoline, cracking heavy gasoline, cracking diesel and cracking heavy oil through oil and gas separation; The catalytic cracking feedstock comprises the first saturated fraction, the second saturated fraction, the third saturated fraction and optional difficult-to-convert components, and the difficult-to-convert components include light hydrocarbons and / or light distillate oil.

2. The process according to claim 1, characterized in that: The crude oil in step (1) is selected from one or more of the following: intermediate base crude oil, intermediate base-cycloalkyl crude oil and cycloalkyl-intermediate base crude oil.

3. The process according to claim 1, characterized in that: The first separation in step (2) includes: contacting the light oil with a first solvent to perform a first extraction separation; Wherein, the first solvent is selected from one or more combinations of sulfolane, methyl sulfolane, dimethyl sulfolane and polyglycol ether solvents; The conditions for the first extraction separation include: a temperature of 60-180° C., a pressure of 0.3-1.2 MPa, and a weight ratio of the first solvent to the light oil of (1-6):

1.

4. The process according to claim 1, characterized in that: The second separation in step (3) comprises: contacting the intermediate oil with an ionic liquid or a second solvent for a second extraction separation; The thermal stability of the ionic liquid is higher than 250°C; Wherein, the ionic liquid comprises cations and anions; the cations are selected from alkyl-substituted imidazoles and / or pyridines; the anions are selected from at least one of hexafluorophosphate, tetrafluoroborate and bis(trifluoromethylsulfonyl)imide; The second solvent is selected from one or more combinations of furfural, dimethyl sulfoxide, N,N-dimethylformamide, N,N-diethylformamide and morpholine; The conditions for the second extraction separation include: a temperature of 15-120° C., a pressure of 0.1-0.5 MPa, and a weight ratio of the ionic liquid to the intermediate oil, or a weight ratio of the second solvent to the intermediate oil, each independently being (1-15):

1.

5. The process according to claim 1, characterized in that: The third separation in step (4) comprises: contacting the heavy oil with a third solvent to perform supercritical extraction separation; Wherein, the third solvent is selected from low carbon alkanes; the low carbon alkanes are selected from one or a mixture of ethane, propane, propylene, n-butane, isobutane, n-pentane, isopentane, hexane, heptane and octane; The conditions for the supercritical extraction separation include: a temperature of 50-100° C., a pressure of 6-20 MPa, and a weight ratio of the third solvent to the heavy oil of (2-5):

1.

6. The process according to claim 1, characterized in that: The process also includes the following steps: Using the first unsaturated fraction from step (2) as a raw material to produce aromatic hydrocarbons; and / or, The second unsaturated fraction from step (3) is used as a raw material for producing high-octane gasoline and / or aromatics; and / or, The third unsaturated fraction from step (4) is used as a raw material for producing needle coke and / or road asphalt; and / or, The cracked gas from step (5) is separated to obtain ethylene, propylene, butene and remaining components.

7. The process according to claim 6, characterized in that: The light hydrocarbons of the difficult-to-convert components include a gaseous hydrocarbon product rich in C4 fraction, preferably including butene obtained by separation of the cracked gas; The light distillate oil of the difficult-to-convert components includes self-produced light distillate oil with a final boiling point of less than 280-360°C and one or more of the following fractions: straight-run naphtha, straight-run kerosene, straight-run diesel produced by other primary processing units, topped oil, raffinate oil, hydrocracking light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline and hydrogenated diesel produced by other secondary processing units; And / or, the light distillate oil of the difficult-to-convert components preferably includes the pyrolysis light gasoline obtained from step (5); The weight proportion of butene as the difficult-to-convert component in the catalytic cracking feedstock is 5-20%; The weight proportion of the cracking light gasoline as the difficult-to-convert component in the catalytic cracking feedstock is 5-20%.

8. The process according to claim 7, characterized in that: The process also includes the following steps: subjecting the second unsaturated fraction from step (3) to a hydrogenation reaction to obtain a hydrogenated component; The catalytic cracking feedstock in step (5) also includes the hydrogenation component; The weight proportion of the hydrogenation component in the catalytic cracking feedstock is 0.1-10%.

9. The process according to claim 1, characterized in that: The conditions for the catalytic cracking reaction in step (5) include: The catalytic cracking raw material is mixed with water vapor and then fed, wherein the reaction temperature is 510-650° C., the reaction time is 1-20 seconds, the weight ratio of the catalyst to the catalytic cracking raw material is (3-50):1, and the weight ratio of the water vapor to the catalytic cracking raw material is (0.03-0.8):1; and / or, The catalyst comprises the following components, based on the dry weight of the components and the catalyst: 1-50 wt% zeolite, 5-99 wt% inorganic oxide, and 0-70 wt% clay; Preferably 5-45 wt% zeolite, 10-80 wt% inorganic oxide, and 5-60 wt% clay; More preferably, it is 10-40 wt% of zeolite, 20-70 wt% of inorganic oxide, and 10-50 wt% of clay.

10. A system for producing high value-added products from crude oil, characterized in that: The system comprises a distillation unit (100), a first separation unit (201), a second separation unit (202), a third separation unit (203) and a catalytic cracking reaction unit (400); The distillation unit (100) is provided with a crude oil inlet (101), a light distillate oil outlet (201a), a middle distillate oil outlet (202a) and a heavy distillate oil outlet (203a); The light fraction oil outlet (201a) of the distillation unit (100) is connected to the inlet of the material to be separated of the first separation unit (201), and the first separation unit (201) is also provided with a first saturated fraction outlet (201b) and a first unsaturated fraction outlet (201c); The middle distillate oil outlet (202a) of the distillation unit (100) is connected to the inlet of the material to be separated of the second separation unit (202), and the second separation unit (202) is also provided with a second saturated fraction outlet (202b) and a second unsaturated fraction outlet (202c); The heavy fraction oil outlet (203a) of the distillation unit (100) is connected to the inlet of the material to be separated of the third separation unit (203), and the third separation unit (203) is also provided with a third saturated fraction outlet (203b) and a third unsaturated fraction outlet (203c); The first saturated outlet (201b), the second saturated outlet (202b) and the third saturated outlet (203b) are respectively connected to the catalytic cracking feedstock inlet of the catalytic cracking reaction unit (400); the catalytic cracking reaction unit (400) is also provided with 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).

11. The system according to claim 10, characterized in that The system is further provided with an aromatics production unit, and the first unsaturated branch outlet (201c) is connected to the raw material inlet of the aromatics production unit; and / or, The system is further provided with a high-octane gasoline production unit, and the second unsaturated outlet (202c) is connected to the raw material inlet of the high-octane gasoline production unit and / or the raw material inlet of the aromatics production unit; and / or, The system is further provided with a needle coke production unit and a road asphalt production unit, and the third unsaturated outlet (203c) is connected to the raw material inlet of the needle coke production unit and / or the raw material inlet of the road asphalt production unit; and / or, The system also includes a gas separation unit, the cracked gas outlet (401) of the catalytic cracking reaction unit (400) is connected to the gas inlet to be separated of the gas separation unit, and the gas separation unit is also provided with an ethylene outlet, a propylene outlet, a butene outlet and a remaining component outlet.

12. The system according to claim 11, characterized in that The catalytic cracking reaction unit (400) is further provided with a difficult-to-convert component inlet (406), and the difficult-to-convert component inlet (406) is connected to the cracking light gasoline outlet (402) and / or the butene outlet of the gas separation unit; and / or, The system is also provided with a hydrogenation reaction unit (300), the second unsaturated branch outlet (202c) is connected to the hydrogenation feedstock inlet of the hydrogenation reaction unit (300), and the hydrogenation product outlet (301) of the hydrogenation reaction unit (300) is connected to the catalytic cracking feedstock inlet of the catalytic cracking reaction unit (400).

13. The system according to claim 10, characterized in that The first separation unit (201) is an extraction separation unit, the second separation unit (202) is an extraction separation unit, and the third separation unit (203) is a supercritical extraction separation unit; The catalytic cracking reaction unit (400) is selected from one or a combination of reactors selected from fluidized bed, turbulent bed, fast bed and dilute phase transport bed; the reactor is selected from one or a series combination of constant linear velocity reactor, constant diameter reactor, variable diameter reactor, upward transport line reactor and downward transport line reactor.

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