A catalytic cracking reaction method and system for improving product selectivity

Abstract

The present application relates to a catalytic cracking reaction method and system for improving product selectivity. The method comprises delivering a light oil and a regenerated catalyst to a cracking reactor for catalytic cracking reaction; delivering a coke feedstock and a regenerated catalyst to a coke generator for coking reaction; delivering a mixed reactant stream and a C4 fraction or C5-C6 light gasoline to a settling section for further cracking reaction; the resulting reaction products are subjected to a separation system; and the resulting regenerated catalyst is delivered to a regenerator for charring, regeneration, and recycling. The catalytic cracking method of the present application can improve ethylene and propylene selectivity, reduce methane generation, and simultaneously address the heat balance issue of the reaction without compromising the physical and chemical properties of the catalyst.

Description

Technical Field

[0001] The present application relates to the technical field of fluidized catalytic cracking, and more specifically, to a reaction method and system for catalytic cracking with improved product selectivity. Background Art

[0002] Currently, there is an oversupply of refining capacity, a slowdown in terminal consumption of refined oil products, and an oversupply of refined oil products, which has become an urgent problem for refining companies. In the chemical raw material market, ethylene and propylene, as basic chemical raw materials, remain in strong market demand. The consumption of ethylene and propylene has been increasing year by year. Taking my country as an example, it is estimated that by the end of 2023, my country's ethylene and propylene production capacity will reach approximately 44 million tons / year and 52 million tons / year, respectively, with an average annual compound growth rate of 11.5% and 8.7%, respectively. As a result, the domestic refining landscape and resource flows will undergo structural reorganization, the growth rate of terminal consumption of refined oil products will slow down, and the consumption of light chemical oil will increase significantly. Therefore, the transformation from refining to chemical industry has become an inevitable direction for the development of refineries. Catalytic cracking, as the link between refining and chemical industry, is a key technology in the transformation process from refining to chemical industry.

[0003] Catalytic cracking processes typically use heavy petroleum hydrocarbons as feedstock, particularly paraffin-based vacuum distillates or atmospheric residues, which yield high yields of light olefins such as propylene. With the increasing heaviness and degradation of global crude oil, high-quality heavy petroleum hydrocarbon resources are becoming increasingly scarce, creating an urgent need to expand the feedstock range for catalytic cracking technology. As refineries adjust and transform their product mix, improving oil quality also generates significant amounts of light petroleum hydrocarbons as byproducts. For a typical 10 million ton fuel oil refinery, annual light petroleum hydrocarbon production can reach millions of tons, representing approximately 10% of crude oil processing capacity. For integrated refining and chemical companies or chemical refineries, the production and proportion of light petroleum hydrocarbons will increase significantly as crude oil conversion deepens. Efficiently utilizing these light hydrocarbon resources has become a key focus of research and attention within the refining and chemical industry.

[0004] Catalytic cracking technologies targeting light olefins as their primary target products feature high conversion rates, high reaction temperatures, and high reaction heat. This requires more heat than conventional fluidized bed catalytic regenerators or other catalytic conversion methods. The coke generated by the cracking itself often fails to meet the heat balance requirements of the reaction-regeneration system. Lighter feedstocks exacerbate this problem of insufficient heat sources. When insufficient coke is generated during the reaction, slurry oil recycling or external fuel oil addition to the regenerator are typically used to provide the required heat. Because slurry oil contains a high concentration of polycyclic aromatic hydrocarbons, it readily adsorbs onto the catalyst's active sites, affecting the accessibility of the active sites to the feedstock molecules and, consequently, the catalytic reaction selectivity. Furthermore, because catalytic cracking utilizes molecular sieves as the active component of the catalyst, the localized high temperatures generated by the combustion of fuel oil within the regenerator cause the aluminum in the molecular sieve framework to gradually dislodge, leading to irreversible damage to the catalyst. This fundamentally addresses the impact of the high-temperature hotspots generated by the localized combustion of external fuel oil on the catalyst's skeletal structure and reaction performance. In order to solve this problem, the existing technical solutions all start from the regenerator system, such as setting up an oxygen-depleted area in the regenerator, introducing fuel oil into the oxygen-depleted area to mix with the catalyst, and then entering the regenerator for burning and regeneration; or arranging a heater in the regenerator and using a fuel nozzle, the fuel nozzle is constructed to spray a mixture of fuel and oxygen-containing gas for combustion to supplement heat; or injecting methane, relying on the combustion heat of methane to supplement heat for the reaction. The heat supplementation method in the above technology has alleviated the adverse effects of the catalyst, but it has not fundamentally solved the impact of the high-temperature hot spots generated by the local combustion of the external fuel oil on the catalyst skeleton structure and reaction performance, thereby seriously affecting the reaction selectivity. Therefore, in the development of light oil catalytic cracking technology, while improving the selectivity of low-carbon olefins, insufficient heat balance is also a technical problem that must be solved. Summary of the Invention

[0005] The purpose of this application is to provide a catalytic cracking reaction method and system for improving product selectivity, increasing ethylene and propylene selectivity, reducing methane selectivity, providing a coke source for the regeneration process, and solving the problem of heat balance in the reaction process from the reaction aspect.

[0006] In one aspect, the present application provides a light oil catalytic cracking method, the method comprising:

[0007] 1) Preheated light oil is introduced from the lower part of the cracking reactor, contacts with the regenerated catalyst from the regenerator and performs a first catalytic cracking reaction from bottom to top to obtain a first reaction product and a first catalyst to be regenerated.

[0008] 2) introducing the coke raw material into the coking reaction zone of the coker, contacting it with the regenerated catalyst from the regenerator and performing a coking reaction to obtain a coker oil; mixing the C4 hydrocarbon fraction and / or the C5-C6 light gasoline fraction into the coker oil at one or more locations in the outlet zone of the coker, and introducing the coke raw material into the dense phase settling section of the settler to perform a second catalytic cracking reaction to obtain a second reaction product and a second catalyst to be regenerated;

[0009] 3) transporting the settler catalyst from the settler to a regenerator for charring and regeneration, and recycling the regenerated catalyst, wherein the settler catalyst includes a first catalyst to be regenerated and a second catalyst to be regenerated;

[0010] 4) introducing the first reaction product and the second reaction product into a separation system for separation.

[0011] In one embodiment, the light oil includes gaseous hydrocarbons and light distillate oil; preferably, the properties of the light oil meet one, two, three or four of the following indicators: density at 20°C is less than 860 kg / m3, residual carbon is 0-0.5% by weight, total aromatic hydrocarbon content is 0%-30% by weight, and the end distillation point is less than 360°C.

[0012] In one embodiment, the conditions of the first catalytic cracking reaction include: a reaction temperature of 510-750°C, a reaction time of 0.5-10 seconds, a catalyst-oil weight ratio of 10:1 to 50:1, a weight ratio of pre-lift gas to feed oil of 0.05:1 to 2.0:1, a catalyst density of 20-100 kg / m3, a linear velocity of 4-18 m / s, and a reaction pressure of 130-450 kPa.

[0013] In one embodiment, the conditions of the coking reaction include: a reaction temperature of 460-650°C, a reaction time of 1-20 seconds, a catalyst-oil weight ratio of 3:1 to 30:1, a weight ratio of pre-lifting gas to coking raw material of 0.01:1 to 0.05:1, a linear velocity of 0.2-0.8 m / s, and a catalyst particle density of 300-700 kg / m3.

[0014] In one embodiment, the conditions of the second catalytic cracking reaction include: a reaction temperature of 490-730°C, a weight hourly space velocity of 0.5-20 hours -1 .

[0015] In one embodiment, the coke raw material is selected from the cracking heavy oil produced by the device and secondary processed distillate oil, or a mixture thereof; preferably, the secondary processed distillate oil can be selected from a mixture of one or more of catalytic cracking diesel, catalytic cracking diesel, catalytic cracking slurry, catalytic cracking slurry, coker gasoline, coker diesel and coker gas oil; more preferably, the coke raw material is the cracking heavy oil produced by the device.

[0016] In another aspect, the present application provides a catalytic cracking reaction-regeneration system, comprising:

[0017] Catalytic cracking reactor,

[0018] coke generator,

[0019] Oil separation equipment,

[0020] settler, and

[0021] Regenerator,

[0022] The catalytic cracking reactor comprises, from bottom to top, the following components:

[0023] optional pre-lift zone;

[0024] A reaction zone, the reaction zone comprising at least one reduced-diameter reaction section, the reduced-diameter reaction section being in the form of a hollow cylinder with a substantially circular cross-section and open bottom and top ends, the inner diameter of which decreases continuously or discontinuously from bottom to top; and

[0025] export zone;

[0026] wherein the optional pre-lifting zone is connected to the bottom end of the reaction zone, the top end of the reaction zone is connected to the outlet zone, and at least one raw material feed port is provided on the optional pre-lifting zone and / or the bottom end of the reaction zone;

[0027] The inner diameter of the cross section of the bottom end of the reaction zone is greater than or equal to the inner diameter of the cross section of the optional pre-lift zone, and the inner diameter of the cross section of the top end is equal to or smaller than the inner diameter of the cross section of the optional pre-lift zone and the inner diameter of the cross section of the outlet zone; the regenerated catalyst inlet is provided at the bottom of the reaction zone and / or the optional pre-lift zone;

[0028] The catalytic cracking reactor is coaxially arranged with the settler, and the oil-agent separation device is accommodated inside the settler. The outlet area of ​​the catalytic cracking reactor is in communication with the oil-agent separation device, so that the oil from the catalytic cracking reactor enters the oil-agent separation device and is separated into a first reaction product and a first spent catalyst.

[0029] The lower part of the settler is provided with a dense phase settling section, and the dense phase settling section of the settler is provided with a catalyst outlet; the catalyst outlet of the settler is connected to the regenerator, so that the settler catalyst in the settler is transported to the regenerator;

[0030] The coke generator comprises, from bottom to top,

[0031] Pre-lift area,

[0032] a coke-forming reaction zone, wherein the coke-forming reaction zone is a bubbling fluidized bed or a turbulent fluidized bed, and

[0033] Export Zone,

[0034] wherein the top of the pre-lifting zone is connected to the coke-generating reaction zone, and the top of the coke-generating reaction zone is connected to the outlet zone;

[0035] The coking device is provided with at least one fuel oil feed port;

[0036] The coke generator is arranged outside the settler, and the outlet area of ​​the coke generator is connected to the dense phase settling section of the settler, so that the material of the coke generator enters the dense phase settling section of the settler;

[0037] The regenerator is provided with a first regenerated catalyst outlet and a second regenerated catalyst outlet, wherein the first regenerated catalyst outlet is connected to the regenerated catalyst inlet of the catalytic cracking reactor, so that at least a portion of the regenerated catalyst is circulated back to the catalytic cracking reactor;

[0038] The bottom end of the pre-lifting zone of the coke maker and / or the bottom end of the coke forming reaction zone is configured to communicate with the second regenerated catalyst outlet of the regenerator, so that at least a portion of the regenerated catalyst of the regenerator is transported to the coke maker.

[0039] In one embodiment, the ratio of the inner diameter to the height of the pre-lift zone of the catalytic cracking reactor is 0.02-0.4:1; the ratio of its height to the total height of the catalytic cracking reactor is 0.01:1 to 0.2:1;

[0040] and / or, the ratio of the inner diameter of the bottom cross-section of the reaction zone of the catalytic cracking reactor to the total height of the catalytic cracking reactor is 0.01:1 to 0.5:1; the ratio of the total height of the reaction zone to the total height of the catalytic cracking reactor is 0.15:1 to 0.8:1;

[0041] And / or, the ratio of the inner diameter of the cross section of the reactor outlet zone to the height is 0.01-0.3:1, and the ratio of the height of the outlet zone to the total height of the reactor is 0.05:1 to 0.5:1.

[0042] In one embodiment, the reaction zone of the catalytic cracking reactor includes 1-3 reduced diameter reaction sections.

[0043] Preferably, the reduced diameter reaction section of the catalytic cracking reactor is in the form of a hollow truncated cone, and the longitudinal section is an isosceles trapezoid; the ratio of the inner diameter of the top cross-section to the height of the reduced diameter reaction section is independently 0.005-0.3:1, the ratio of the inner diameter of the bottom cross-section to the height of the reduced diameter reaction section is independently 0.015-0.25:1, and the ratio of the inner diameter of the bottom cross-section to the inner diameter of the top cross-section is independently greater than 1.2 and less than or equal to 10; the ratio of the height of the reduced diameter reaction section to the total height of the catalytic cracking reactor is independently 0.15:1 to 0.8:1.

[0044] In one embodiment, the pre-lifting zone of the catalytic cracking reactor is connected to the reaction zone by a first connecting section, the longitudinal section of the first connecting section is an isosceles trapezoid, and the outward inclination angle α of the side of the isosceles trapezoid is 5-85°.

[0045] In one embodiment, the coke generator is provided with the pre-lift gas inlet, the catalyst inlet and two fuel oil inlets in order from bottom to top;

[0046] Among them, one of the fuel oil inlets is arranged upstream of the coking reaction zone of the coking device, and one of the fuel oil inlets is arranged downstream of the coking reaction zone of the coking device.

[0047] In one embodiment, the coke-generating reaction zone is a hollow cylinder with an aspect ratio of 20:1 to 2:1.

[0048] In one embodiment, the pre-lifting zone of the coke generator is a hollow cylinder with an aspect ratio of 10:1 to 2:1;

[0049] The outlet area of ​​the coke generator is a hollow cylinder with an aspect ratio of 30:1-5:1;

[0050] Preferably, the ratio of the inner diameters of the pre-lifting zone of the coke generator, the coke generating reaction zone of the coke generator, and the outlet zone of the coke generator is 1:2:1 to 1:10:2.

[0051] In the present application, the reduced diameter reaction section, especially the reduced diameter structure of the conical reaction section, set in the cracking reactor in the system of the present application is conducive to accelerating the reaction oil and gas to leave the reaction zone, shortening the reaction time, and reducing the catalyst backmixing, which is conducive to reducing the secondary conversion reaction of the light olefins generated by the primary reaction and improving the selectivity of light olefins.

[0052] In the present application, the C4 hydrocarbon or C5-C6 light gasoline fraction is transported to the dense phase settling section through the coking device outlet pipeline for the second cracking reaction, which not only avoids the competitive reaction of the olefin components in the cracking reactor, but also provides a suitable reaction environment for the polymerization and re-cracking reaction of the C4 hydrocarbon or C5-C6 light gasoline fraction, thereby improving the selectivity of ethylene and propylene.

[0053] In the present application, by setting up a coker, the fuel oil can be mixed with the catalyst under low-temperature, oxygen-free fluidized conditions, and a coking reaction occurs in the coker reaction zone having the characteristics of a bubbling bed or a turbulent fluidized bed. Not only is the coke selectivity high, but the coke is also evenly distributed on the catalyst, which is conducive to uniform combustion in the regeneration system.

[0054] In the present application, the coke-containing catalyst generated by the coke generator can be mixed with the coke-containing catalyst generated by the cracking reactor and enter the regeneration system. The coke on the catalyst can be fully burned and released heat under the action of high-temperature, oxygen-rich gas, supplying the heat required for the reaction without damaging the properties of the catalyst. This realizes the replenishment of coke source from the reaction system end and solves the heat balance problem of the catalytic cracking device.

[0055] When the method and system of this application are used in catalytic cracking reactions, the contact efficiency between the feedstock and the catalyst is high, the catalytic reaction selectivity is good, the yield of high-value-added products such as ethylene and propylene is high, and the yield of byproducts such as methane is low. This helps refineries transform, develop, and expand from oil refining to chemical raw material production, solving the problem of petrochemical raw material shortages and improving the economic benefits of refineries. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following detailed description, they are used to explain the present application but do not constitute a limitation of the present application. In the accompanying drawings:

[0057] Figure 1 Schematic diagram of the catalytic cracking reactor in the system of this application;

[0058] Figure 2 A schematic diagram of a coke generator in the system of this application;

[0059] Figure 3 A schematic diagram of a catalytic cracking system according to an embodiment of the present application. DETAILED DESCRIPTION

[0060] The present application will be further described in detail below through the accompanying drawings and examples, through which the features and advantages of the present application will become more clear and distinct.

[0061] The word "exemplary" is used exclusively herein to mean "serving as an example, example, 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 indicated.

[0062] 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.

[0063] Any specific numerical value disclosed herein (including the endpoints of a numerical range) is not limited to the exact value of the numerical value, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Moreover, for a disclosed numerical range, any combination of the endpoints of the range, between the endpoints and the specific points in the range, and between the specific points can be used to generate one or more new numerical ranges, and these new numerical ranges should also be considered to be specifically disclosed herein.

[0064] In this application, the terms "upstream" and "downstream" are used in relation to the direction of flow of the reactants. For example, when the reactants flow from bottom to top, "upstream" refers to a position below, while "downstream" refers to a position above.

[0065] 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.

[0066] The present application provides a light oil catalytic cracking method, the method comprising:

[0067] 1) Preheated light oil is introduced from the lower part of the cracking reactor, contacts with the regenerated catalyst from the regenerator and performs a first catalytic cracking reaction from bottom to top to obtain a first reaction product and a first catalyst to be regenerated.

[0068] 2) introducing the coke raw material into the coking reaction zone of the coker, contacting it with the regenerated catalyst from the regenerator and performing a coking reaction to obtain a coker oil; mixing the C4 hydrocarbon fraction and / or the C5-C6 light gasoline fraction into the coker oil at one or more locations in the outlet zone of the coker, and introducing the coke raw material into the dense phase settling section of the settler to perform a second catalytic cracking reaction to obtain a second reaction product and a second catalyst to be regenerated;

[0069] 3) transporting the settler catalyst from the settler to a regenerator for charring and regeneration, and recycling the regenerated catalyst, wherein the settler catalyst includes a first catalyst to be regenerated and a second catalyst to be regenerated;

[0070] 4) introducing the first reaction product and the second reaction product into a separation system for separation.

[0071] The present application also provides a catalytic cracking reaction-regeneration system, comprising:

[0072] Catalytic cracking reactor,

[0073] coke generator,

[0074] Oil separation equipment,

[0075] settler, and

[0076] Regenerator,

[0077] The catalytic cracking reactor comprises, from bottom to top, the following components:

[0078] optional pre-lift zone;

[0079] A reaction zone, the reaction zone comprising at least one reduced-diameter reaction section, the reduced-diameter reaction section being in the form of a hollow cylinder with a substantially circular cross-section and open bottom and top ends, the inner diameter of which decreases continuously or discontinuously from bottom to top; and

[0080] export zone;

[0081] wherein the optional pre-lifting zone is connected to the bottom end of the reaction zone, the top end of the reaction zone is connected to the outlet zone, and at least one raw material feed port is provided on the optional pre-lifting zone and / or the bottom end of the reaction zone;

[0082] The inner diameter of the cross section of the bottom end of the reaction zone is greater than or equal to the inner diameter of the cross section of the optional pre-lift zone, and the inner diameter of the cross section of the top end is equal to or smaller than the inner diameter of the cross section of the optional pre-lift zone and the inner diameter of the cross section of the outlet zone; the regenerated catalyst inlet is provided at the bottom of the reaction zone and / or the optional pre-lift zone;

[0083] The catalytic cracking reactor is coaxially arranged with the settler, and the oil-agent separation device is accommodated inside the settler. The outlet area of ​​the catalytic cracking reactor is in communication with the oil-agent separation device, so that the oil from the catalytic cracking reactor enters the oil-agent separation device and is separated into a first reaction product and a first spent catalyst.

[0084] The lower part of the settler is provided with a dense phase settling section, and the dense phase settling section of the settler is provided with a catalyst outlet; the catalyst outlet of the settler is connected to the regenerator, so that the settler catalyst in the settler is transported to the regenerator;

[0085] The coke generator comprises, from bottom to top,

[0086] Pre-lift area,

[0087] a coke-forming reaction zone, wherein the coke-forming reaction zone is a bubbling fluidized bed or a turbulent fluidized bed, and

[0088] Export Zone,

[0089] wherein the top of the pre-lifting zone is connected to the coke-generating reaction zone, and the top of the coke-generating reaction zone is connected to the outlet zone;

[0090] The coking device is provided with at least one fuel oil feed port;

[0091] The coke generator is arranged outside the settler, and the outlet area of ​​the coke generator is connected to the dense phase settling section of the settler, so that the material of the coke generator enters the dense phase settling section of the settler;

[0092] The regenerator is provided with a first regenerated catalyst outlet and a second regenerated catalyst outlet, wherein the first regenerated catalyst outlet is connected to the regenerated catalyst inlet of the catalytic cracking reactor, so that at least a portion of the regenerated catalyst is circulated back to the catalytic cracking reactor;

[0093] The bottom end of the pre-lifting zone of the coke maker and / or the bottom end of the coke forming reaction zone is configured to communicate with the second regenerated catalyst outlet of the regenerator, so that at least a portion of the regenerated catalyst of the regenerator is transported to the coke maker.

[0094] The method of the present application can be performed in the system of the present application. The catalytic cracking method of the present application is further described below in conjunction with the catalytic cracking reaction-regeneration system. The following description of the catalytic cracking method of the present application is also applicable to the catalytic cracking reaction-regeneration system of the present application, and vice versa.

[0095] Figure 3 The catalytic cracking reaction-regeneration system of the present application is shown, and the catalytic cracking reaction-regeneration system comprises:

[0096] Catalytic cracking reactor 100,

[0097] Coke generator 300,

[0098] Oil separation equipment 201,

[0099] settler 200, and

[0100] Regenerator 500.

[0101] like Figure 1 As shown, the catalytic cracking reactor 100 can be provided with a pre-lift gas inlet 101, one or more cracking feedstock inlets (e.g., a cracking feedstock feed inlet 102 at the bottom), a catalyst inlet 103 at the bottom, and an oil agent outlet 104 at the top. The oil agent outlet 104 of the cracking reactor is in fluid communication with the oil agent separation device 201, so that the first reaction oil gas and the first spent catalyst from the catalytic cracking reactor 100 are separated in the oil agent separation device 201.

[0102] In one embodiment, the catalytic cracking reactor 100 includes, from bottom to top:

[0103] Optional pre-lift zone I,

[0104] Reaction zone II, wherein the reaction zone II includes at least one reduced-diameter reaction section, wherein the reduced-diameter reaction section is a hollow cylinder with a substantially circular cross-section and open bottom and top ends, and the inner diameter of the hollow cylinder decreases continuously or discontinuously from bottom to top; and

[0105] Export Zone III,

[0106] The optional pre-elevation zone I is connected to the bottom end of the reaction zone II, the top end of the reaction zone II is connected to the outlet zone III, and at least one raw material feed port 102 is provided on the optional pre-elevation zone and / or the bottom end of the reaction zone;

[0107] The cross-sectional inner diameter of the bottom end of the reaction zone II is greater than or equal to the cross-sectional inner diameter of the optional pre-lift zone I, and the cross-sectional inner diameter of the top end is equal to or less than the cross-sectional inner diameter of the optional pre-lift zone and the cross-sectional inner diameter of the outlet zone.

[0108] like Figure 1 As shown, the catalytic cracking reactor may include the pre-lifting zone I, which is arranged at the bottom of the catalytic cracking reactor and is used to pre-lift the catalyst entering the reactor. Figure 1 As shown, a catalyst inlet 103 is provided at the lower part of the pre-lifting zone I for inputting the catalyst. The pre-lifting zone I can be a hollow cylindrical structure, and the ratio of its inner diameter to height is 0.02-0.4:1; the ratio of its height to the total height of the reactor is 0.01:1 to 0.2:1, preferably 0.05:1 to 0.15:1. In one embodiment, the inner diameter of the pre-lifting zone I can be 0.2-5 meters, preferably 0.4-3 meters. In an embodiment in which a pre-lifting zone I is present, a pre-lifting medium can be input into the pre-lifting zone I through a pre-lifting gas inlet 101. In an embodiment in which a pre-lifting zone I is present, at least one catalyst inlet 103 can also be provided at the bottom of the pre-lifting zone I for allowing the catalyst to pass through the pre-lifting zone I into the reactor.

[0109] According to the present application, the pre-lift zone I is not necessary. For example, when the reaction zone II of the reactor of the present application is used in series with other reactors such as a riser reactor, the reaction zone II can be directly connected to the outlet of the other reactor located upstream without the need to use the pre-lift zone I. In one embodiment, the catalytic cracking reactor may not include the pre-lift zone I. At this time, the bottom of the reaction zone II may be provided with at least one raw material feed port 102 to facilitate the entry of raw materials and the like into the catalytic cracking reactor. In an embodiment in which there is no pre-lift zone I, the bottom of the reaction zone II may be provided with at least one catalyst inlet (not shown) for allowing the catalyst to enter the reactor. Of course, the reaction zone II may not be provided with a catalyst inlet, and the catalyst therein may be derived from the catalyst carried in the logistics of other reactors. Both embodiments are within the scope of protection of the present application.

[0110] like Figure 1 As shown, the catalytic cracking reactor may include a reaction zone II. A pre-lift zone I is connected to the bottom end 110 of the reaction zone II, and the top end 120 of the reaction zone II is connected to the outlet zone III. At least one catalyst inlet 103 and at least one raw material feed port 102 are provided on the pre-lift zone and / or at the bottom of the reaction zone. The inner diameter of the cross section of the bottom end 110 of the reaction zone II is greater than or equal to the inner diameter of the cross section of the pre-lift zone I, and the inner diameter of the cross section of the top end 120 is equal to or less than the inner diameter of the cross section of the pre-lift zone I and the inner diameter of the cross section of the outlet zone III.

[0111] In the catalytic cracking reactor provided in the present application, the reaction zone II is a fluidized bed. Preferably, the fluidized bed is one or a combination of a transport fluidized bed, a turbulent fluidized bed and a fast bed.

[0112] In one embodiment, the pre-elevation zone I is connected to the reaction zone II via a first transition section I-1. The longitudinal section of the first transition section I-1 may be an isosceles trapezoid, and the outward inclination angle α of the side of the isosceles trapezoid may be 5-85°, preferably 15-75°.

[0113] like Figure 1 As shown, the raw material feed port can be provided at the upper portion of the pre-elevation zone I, in the first transition section I-1, or at the lower portion of the reaction zone II. In particular, in an embodiment where the pre-elevation zone I is not present, a raw material feed port 102 can be provided at the lower portion of the reaction zone II for feeding raw materials.

[0114] In one embodiment, the ratio of the inner diameter of the bottom cross-section of the reaction zone II to the total height of the reactor is 0.01:1 to 0.5:1, preferably 0.05:1 to 0.2:1; the ratio of the total height of the reaction zone II to the total height of the reactor is 0.15:1 to 0.8:1, for example 0.2:1 to 0.75:1.

[0115] like Figure 1 As shown, the reaction zone II includes at least one diameter-reducing reaction section, which is a hollow cylinder with a roughly circular cross-section and open bottom and top ends, and its inner diameter decreases continuously or discontinuously from bottom to top.

[0116] In this application, "reduced diameter" refers to a decrease in inner diameter in a discontinuous manner, such as steps or jumps, or in a continuous manner. An example of a "reduced diameter section with a discontinuous decrease in inner diameter from bottom to top" includes a column consisting of two or more hollow cylinders with decreasing inner diameters.

[0117] For example, the reaction zone II may be cylindrical, including one or more hollow truncated cone sections, or may be cylindrical, including two or more hollow cylindrical sections. According to the present application, when the reaction zone includes two or more reduced diameter reaction sections, the reduced diameter reaction sections may have the same or different heights, and this application does not impose strict restrictions on this.

[0118] In a preferred embodiment, the reaction zone II comprises a cylindrical form consisting of one or more hollow truncated conical segments and optional connecting segments for connecting adjacent hollow truncated conical segments, or a cylindrical form consisting of two or more hollow cylindrical segments and optional connecting segments for connecting adjacent hollow cylindrical segments.

[0119] In one embodiment, Figure 1 As shown, the reaction zone II includes a reduced diameter reaction section, which is in the form of a hollow truncated cone, and its longitudinal section is an isosceles trapezoid; the inner diameter D of the top cross section is 120 The height h of the reduced diameter reaction section II The ratio is 0.005-0.3:1 independently, and the inner diameter D of the bottom cross section 110 The height h of the reduced diameter reaction section II The ratio is 0.015-0.25:1 independently, and the inner diameter of the bottom cross section D 110 and the inner diameter D of the top cross section 120 The ratio of each is independently greater than 1.2 and less than or equal to 10, more preferably 1.5 to 5; the diameter reduction reaction section h II The ratio of the height of the bottom end to the total height h of the reactor is 0.15:1 to 0.8:1, preferably 0.2:1 to 0.75:1. In one embodiment, the inner diameter D of the bottom cross section is110 The ratio of the height h1 of the reduced diameter reaction section to the total height h of the reactor is 0.01:1 to 0.5:1, preferably 0.05:1 to 0.2; the ratio of the height h1 of the reduced diameter reaction section to the total height h of the reactor is 0.15:1 to 0.8:1, preferably 0.2:1 to 0.75:1, and the total height h1 of the reaction zone II is 0.15:1 to 0.8:1, preferably 0.2:1 to 0.75:1. II The ratio of the inner diameter D of the top cross section of the reduced diameter reaction section 100 to the total height h of the reactor is 0.15:1 to 0.8:1, preferably 0.2:1 to 0.75:1. 110 In one embodiment, the total height h of the reaction zone II is 0.2-5 meters, preferably 0.4-3 meters. II It may be about 2-50 meters, preferably about 5-40 meters, and more preferably about 8-20 meters.

[0120] In the catalytic cracking reactor of the present application, the reduced-diameter reaction section, especially the conical reaction section, has a large bottom space, which can effectively increase the catalyst density in the reactor, thereby greatly increasing the ratio of catalyst to reaction raw materials in the reactor, strengthening the primary cracking reaction of the raw materials, not only improving the reaction conversion rate, but also increasing the yield of light olefins; moreover, the reduced-diameter reaction section, especially the reduced-diameter structure of the conical reaction section, is conducive to accelerating the reaction oil and gas to leave the reaction zone, shortening the reaction time, and reducing catalyst backmixing, which is conducive to reducing the secondary conversion reaction of the light olefins generated by the primary reaction and improving the selectivity of light olefins.

[0121] In the catalytic cracking reactor provided herein, the reactor may be provided with one or more, for example, one, two or more, raw material feed ports, and the one or more raw material feed ports may be independently provided at the outlet end of the pre-elevation zone I, or at the bottom of the reaction zone II. Further preferably, the positions of the multiple raw material inlets are independently located at the same height or at different heights of the reaction zone II. Thus, raw materials of different properties can be fed separately at different raw material feed ports.

[0122] like Figure 1 As shown, the catalytic cracking reactor may include an outlet zone III. In one embodiment, the outlet zone III may be in the form of a hollow cylinder with a cross-sectional inner diameter and a height h III The ratio is 0.01-0.3:1, the height h of the outlet area III The ratio to the total height h of the reactor is 0.05: 1 to 0.5: 1, more preferably 0.1: 1 to 0.35: 1. In one embodiment, the inner diameter of the outlet zone III is 0.2-5 meters, preferably 0.4-3 meters.

[0123] As mentioned above, the inner diameter of the cross section at the top of reaction zone II is equal to or smaller than the inner diameter of the cross section of outlet zone III. In one embodiment, the inner diameter of the cross section at the top of reaction zone II is equal to the inner diameter of the cross section of outlet zone III.

[0124] In one embodiment, the inner diameter of the cross section at the top of reaction zone II is smaller than the inner diameter of the cross section of outlet zone III. In this case, reaction zone II and outlet zone III may be connected by a third transition section (not shown). The longitudinal section of the third transition section may be an isosceles trapezoid, and the outward inclination angle of the side of the isosceles trapezoid may be 5-85°, preferably 15-75°.

[0125] In the present application, the catalytic cracking reactor 100 is coaxially arranged with the settler 200, and the oil separation device 201 is housed within the settler 200. The outlet zone of the catalytic cracking reactor is connected to the oil separation device, so that the oil from the catalytic cracking reactor enters the oil separation device and is separated into a first reaction product and a first regenerated catalyst. In one embodiment, the outlet end 104 of the outlet zone III can be directly connected to the inlet of the oil separation device 201, such as a cyclone separator. In the present application, the oil separation device 201 can be a device well known to those skilled in the art, such as a cyclone separator.

[0126] In one embodiment, the light oil includes gaseous hydrocarbons and light distillate oil. The light oil has properties that meet one, two, three, or four of the following criteria: a density of less than 860 kg / m³ at 20°C, a carbon residue of 0-0.5% by weight, a total aromatics content of 0%-30% by weight, and an end-of-range boiling point of less than 360°C.

[0127] In one embodiment, the gaseous hydrocarbons can be selected from a mixture of one or more of saturated liquefied gas, unsaturated liquefied gas, and C4 fractions; the light distillate oil includes petroleum hydrocarbons, oxygen-containing compounds, and distillate oils generated from biomass or waste plastics with a distillation range of 25 to 360°C; the petroleum hydrocarbons can be selected from a mixture of one or more of primary processed straight-run naphtha, straight-run kerosene, and straight-run diesel; and a mixed oil of one or more of secondary processed topped oil, raffinate oil, hydrocracked light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline, and hydrogenated diesel.

[0128] In one embodiment, the catalyst comprises, on a dry basis and based on the dry weight of the catalyst, 1-50 wt%; 5-99 wt% inorganic oxide, and 0-70 wt% clay. The zeolite comprises a medium-pore zeolite and an optional large-pore zeolite, wherein the medium-pore zeolite is selected from the group consisting of ZSM series zeolites, ZRP zeolites, and any combination thereof; and the large-pore zeolite is selected from the group consisting of rare earth Y-type zeolites, rare earth hydrogen Y-type zeolites, ultrastable Y-type zeolites, and high-silica Y-type zeolites, and any combination thereof. On a dry basis, the medium-pore zeolite accounts for 10-100 wt%, preferably 50-90 wt%, of the total weight of the zeolite.

[0129] In the present application, the medium-pore zeolite and large-pore zeolite are defined in accordance with conventional definitions 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.

[0130] 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 a mixture of one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other zeolites of similar structures. A more detailed description of ZSM-5 can be found in U.S. Patent No. 3,702,886A.

[0131] According to the present application, the inorganic oxide as a binder is preferably silicon dioxide (SiO2) and / or aluminum oxide (Al2O3). The clay as a matrix (ie, a carrier) is preferably kaolin and / or halloysite.

[0132] In one embodiment, the conditions of the catalytic cracking reaction include: a reaction temperature of 550-750°C, a reaction time of 0.5-10 seconds, a catalyst-oil weight ratio of 10:1 to 50:1, a weight ratio of pre-lift gas to feed oil of 0.05:1 to 2.0:1, a catalyst density of 20-100 kg / m3, a linear velocity of 4-18 m / s, and a reaction pressure of 130-450 kPa.

[0133] In one embodiment, the feedstock oil is introduced into the cracking reactor at one location, or the feedstock oil is introduced into the cracking reactor at more than one location, which may be the same or different.

[0134] In one embodiment, the method further comprises introducing a C4 hydrocarbon fraction and / or a C5-C6 light gasoline fraction into the dense phase settling section for a second catalytic cracking reaction.

[0135] In this application, the C4 hydrocarbon fraction refers to low-molecular-weight hydrocarbons that exist in gaseous form at room temperature and pressure and have the C4 fraction as a main component, including alkanes, alkenes, and alkynes with 4 carbon atoms in their molecules. It can include both gaseous hydrocarbon products rich in the C4 hydrocarbon fraction produced by the method of the present invention (e.g., liquefied gas) and gaseous hydrocarbons rich in the C4 fraction produced by other devices. The C4 hydrocarbon fraction produced by the method of the present invention is preferred. The C4 hydrocarbon fraction is preferably a C4 hydrocarbon fraction rich in olefins, and the C4 olefin content can be greater than 50% by weight, preferably greater than 60% by weight, and more preferably greater than 70% by weight.

[0136] In the present application, the C5-C6 light gasoline fraction may include the pyrolysis gasoline produced by the method of the present invention, or may include gasoline fractions produced by other devices, for example, at least one C5-C6 fraction selected from catalytic pyrolysis gasoline, catalytic cracking gasoline, straight-run gasoline, coker gasoline, thermal pyrolysis gasoline, thermal cracking gasoline, and hydrogenated gasoline. The C5-C6 light gasoline is preferably an olefin-rich fraction, wherein the olefin content is greater than 50% by weight, preferably greater than 60% by weight.

[0137] In one embodiment, C4 hydrocarbons or C5-C6 light gasoline fraction is introduced at one or more locations in the outlet zone of the coker, as described below.

[0138] In one embodiment, the conditions for the second catalytic cracking reaction include: a reaction temperature of 490-730°C, a weight hourly space velocity of 0.5-20 hours -1 .

[0139] In one embodiment, the amount of coking raw materials introduced into the coker accounts for 10-50 wt% of the raw material feed into the cracking reactor; the amount of C4 hydrocarbons or C5-C6 light gasoline fraction introduced into the coker accounts for 3-30 wt% of the raw material feed into the cracking reactor.

[0140] like Figure 2 As shown, the catalytic cracking coke generator 300 of the present application is suitable for adjusting heat balance. The coke generator 300 includes, from bottom to top, a pre-lifting zone I', a coke generating reaction zone II', and an outlet zone III'.

[0141] The coker 300 is equipped, from bottom to top, with a pre-lift gas inlet 301, a catalyst inlet 303, and fuel oil inlets 302 and 305, as well as inlets for inputting the C4 hydrocarbon fraction and / or the C5-C6 light gasoline fraction. The pre-lift gas inlet 301 is typically located in the pre-lift zone I', typically at its bottom. The catalyst inlet 303 can be located in the pre-lift zone I' and / or the coking reaction zone II', but is typically located in the pre-lift zone I', at its lower portion, but above the pre-lift gas inlet 301, allowing the pre-lift gas to lift the incoming catalyst. This allows the regenerated catalyst to be pre-accelerated and pre-fluidized, improving its distribution and facilitating uniform contact and rapid mixing with the fuel oil.

[0142] The bottom of the regenerator 500 (eg Figure 3 The catalyst inlet 303 is connected to the coke generator 300, allowing the catalyst to enter the coke generator to generate coke, thereby producing a coked catalyst. The top of the coke generator 300 is connected to the oil separation device 201, which separates the coked catalyst from the reaction oil and gas.

[0143] In one embodiment, the pre-lifting zone I', the coking reaction zone II', and the outlet zone III' are connected in sequence, that is, the top of the pre-lifting zone I' is connected to the coking reaction zone II', and the top of the coking reaction zone II' is connected to the outlet zone III'.

[0144] In the present application, the coke maker 300 has independently provided pre-lift gas inlet 301, regenerated catalyst inlet 303, and one or more fuel oil inlets 302 located at different heights of the coke maker 300. Preferably, the coke maker is provided with the pre-lift gas inlet 301 and the regenerated catalyst inlet 303 in order from bottom to top.

[0145] In the present application, the reaction zone of the coke generator 300 is a bubbling bed or a turbulent fluidized bed. In one embodiment, the reaction zone is a hollow cylinder with an aspect ratio of 20:1 to 2:1.

[0146] In one embodiment, the coke raw materials are introduced into the coke maker from one or more identical or different positions at the coke maker inlet. In one embodiment, the coke raw materials are introduced into the coke maker outlet from one or more identical or different positions.

[0147] In the present application, the coke generator may be provided with one or more, for example, one, two or more fuel oil inlets 302, 305. Figure 3As shown, a fuel oil inlet 302 is located upstream of the coking reaction zone, and a fuel oil inlet 305 is located downstream of the coking reaction zone. Pre-lift gas enters the coking vessel 300 from the bottom through the pre-lift gas inlet 301. High-temperature regenerated catalyst from the regenerator and / or settler catalyst from the dense-phase settling section enter the lower portion of the coking vessel 300, mixes with the pre-lift gas, and moves upward. Coking crude oil is then injected into the coking vessel through the fuel oil inlet 302, where it comes into contact with the regenerated catalyst and enters the coking vessel to initiate the coking reaction. C4 hydrocarbons or a C5-C6 light gasoline fraction are introduced into the coking vessel through the fuel oil inlet 305, mixed with the material exiting the coking reaction zone, and introduced into the dense-phase settling section of the settler to undergo the aforementioned second catalytic cracking reaction.

[0148] In the present application, the fuel oil injected through the fuel oil inlet 302 may include straight-run distillate oil or secondary processed distillate oil. Preferably, the secondary processed distillate oil may be selected from a mixture of one or more of catalytic cracking diesel, catalytic cracking slurry oil, coker gasoline, coker diesel and coker gas oil.

[0149] In one embodiment, the pre-elevation zone I' is a hollow cylindrical shape with an aspect ratio of 10:1 to 2:1. In one embodiment, the outlet zone III' is a hollow cylindrical shape with an aspect ratio of 30:1 to 5:1. In one embodiment, the ratio of the inner diameters of the pre-elevation zone I', the coking reaction zone II', and the outlet zone III' is 1:2:1 to 1:10:1.

[0150] In one embodiment, the conditions of the coking reaction include: a reaction temperature of 460-560°C, a reaction time of 1-20 seconds, a catalyst-oil weight ratio of (3-30):1, a weight ratio of pre-lifting gas to coking raw material of (0.01-0.5):1, a linear velocity of 0.2 m / s-1.2 m / s, and a catalyst particle density of 300 kg / m3-700 kg / m3.

[0151] In one embodiment, the coke-forming feedstock is a pyrolysis heavy oil produced in the plant and a secondary processed distillate, or a mixture thereof. Preferably, the secondary processed distillate can be a mixture of one or more of catalytically cracked diesel, catalytically cracked diesel, catalytically cracked slurry oil, catalytically cracked slurry oil, coker gasoline, coker diesel, and coker gas oil. More preferably, the coke-forming feedstock is a pyrolysis heavy oil produced in the plant.

[0152] In one embodiment, the linear velocity of the reaction zone of the coke generator is 0.2 m / s to 1.2 m / s, and the catalyst particle density is 300 kg / m3 to 700 kg / m3.

[0153] In one embodiment, the pre-lift gas is selected from water vapor, nitrogen, dry gas, rich gas or C4 fraction or a mixture thereof, and the mass ratio of the pre-lift gas to fuel oil is 0.01:1 to 0.05:1.

[0154] In one embodiment, the fuel oil comprises straight-run distillate or secondary processed distillate. Preferably, the secondary processed distillate can be selected from a mixture of one or more of catalytic cracking diesel, coker gasoline, coker diesel and coker gas oil.

[0155] In one embodiment, the atomizing medium of the fuel oil can be selected from water vapor, nitrogen or a mixture thereof, and the mass ratio of the atomizing medium to the combustion oil is 0.01:1 to 0.5:1.

[0156] In one embodiment, the outlet temperature of the coke generator is 460-560°C.

[0157] In one embodiment, the coke generator 300 is located outside the settler 200 and arranged in parallel with the catalytic cracking reactor 100. The coke generator's outlet zone III' is connected to the dense phase settling section 205 located at the bottom of the settler, allowing the coke generator's materials to enter the dense phase settling section 205. Within this dense phase settling section 205, C4 hydrocarbons or C5-C6 light gasoline fractions injected through the fuel oil inlet 305 and materials from the coke generator (including oil and gas) come into contact with the first spent catalyst separated by the oil-agent separation device 201, undergoing a second catalytic cracking reaction to produce a second reaction product and a second spent catalyst. In one embodiment, the outlet end 304 of the coke generator 300 is connected to the dense phase settling section 205 of the settler. In one embodiment, the oil-agent separation device 201 is housed within the settler 200, allowing the catalyst separated by the oil-agent separation device 201 to settle within the settler 200. At the same time, a stripping gas inlet 207 is provided at the lower portion of the dense phase settling section 205 for inputting a stripping gas, such as water vapor, for stripping the catalyst (including the first spent catalyst and the second spent catalyst, collectively referred to herein as the settler catalyst) within the dense phase settling section 205. The regenerator 500 is connected to the dense phase settling section 205 so that the stripped settler catalyst is delivered to the regenerator 500.

[0158] In one embodiment, the dense phase settling section 205 of the settler is provided with a catalyst outlet 206; the catalyst outlet 206 of the settler is connected to the regenerator 500, so that the settler catalyst in the settler is transported to the regenerator.

[0159] like Figure 3As shown, the regenerator 500 is used to regenerate the catalyst to be regenerated. The lower part is provided with an oxygen-containing gas inlet 501, a regenerated catalyst inlet 505 and two regenerated catalyst outlets 506 and an outlet 508. A cyclone separator 503 is provided inside and a flue gas outlet 504 is provided on the top.

[0160] like Figure 3 As shown, the first regenerated catalyst outlet 506 is connected to the regenerated catalyst inlet 103 of the catalytic cracking reactor, so that at least a portion of the regenerated catalyst is circulated back to the catalytic cracking reactor 100. In one embodiment, the bottom end of the pre-lift zone I' of the coke generator and / or the bottom end of the coke generation reaction zone II' are configured to be connected to the second regenerated catalyst outlet 508 of the regenerator; in one embodiment, the catalyst inlet 303 of the coke generator is connected to the second regenerated catalyst outlet 508 of the regenerator, so that at least a portion of the regenerated catalyst of the regenerator is circulated back to the coke generator 300, allowing the catalyst to enter the coke generator to generate coke, thereby obtaining a coked catalyst.

[0161] In one embodiment, the conditions of the regenerator are: the regeneration temperature is 550-750°C, preferably 600-730°C, more preferably 650-700°C; the gas superficial velocity is 0.5-3 m / s, preferably 0.8-2.5 m / s, more preferably 1-2 m / s, and the average residence time of the catalyst to be regenerated is 0.6-3 minutes, preferably 0.8-2.5 minutes, more preferably 1-2 minutes.

[0162] In one embodiment, the regenerated catalyst recycled to the catalytic cracking reactor 100 accounts for 50-90% of the total amount of regenerated catalyst, based on the total weight of the regenerated catalyst; the regenerated catalyst recycled to the coker 300 accounts for 10-50% of the total amount of regenerated catalyst, based on the total weight of the regenerated catalyst.

[0163] The reaction oil and gas (i.e., reaction products) separated by the oil agent separation device 201 are collected in a gas collection chamber 202 and then transported via pipeline 203 to a subsequent reaction product separation device (not shown) for separation. The reaction product separation device can be equipped with a reaction product inlet, a dry gas outlet, a liquefied gas outlet, a pyrolysis gasoline outlet, and a pyrolysis heavy oil outlet, for separating the reaction products into dry gas, liquefied gas, pyrolysis gasoline, and pyrolysis heavy oil components according to their distillation range. The dry gas and liquefied gas are then further separated by the gas separation device to obtain methane, ethylene, propylene, and mixed C4 components. The pyrolysis gasoline is further separated to obtain pyrolysis light gasoline and heavy gasoline. The methods for separating ethylene and propylene from the reaction products are similar to conventional methods in the art and are not limited by the present invention and will not be described in detail here.

[0164] In the catalytic cracking system provided herein, the settler, oil separation equipment, regenerator, other devices, reaction product separation system, etc. may all be devices well known to those skilled in the art, and the connections between these devices may also be made in accordance with methods known in the art. For example, the oil separation equipment may include a cyclone separator and an outlet rapid separator.

[0165] The catalytic cracking method and system of the present application can efficiently produce chemical raw materials such as ethylene and propylene from light petroleum hydrocarbons. It can not only fundamentally solve the problem of heat balance, but also reduce the damage caused to the catalyst and regeneration system by the traditional method of spraying combustion oil, saving catalyst costs, and helping refineries to transform, develop and extend from oil refining to chemical raw material production, which not only solves the problem of shortage of petrochemical raw materials, but also improves the economic benefits of refineries.

[0166] The present application will be further described below with reference to the preferred embodiments shown in the accompanying drawings, but the present application is not limited thereby.

[0167] Figure 3 A preferred embodiment of the catalytic cracking reaction system of the present application is given.

[0168] The pre-lift gas enters the pre-lift zone I of the cracking reactor from the bottom of the cracking reactor 100 through the pre-lift gas inlet 101. The high-temperature regenerated catalyst from the regenerator enters the pre-lift zone I at the bottom of the cracking reactor 100 through the catalyst inlet 103, mixes with the pre-lift gas, moves upward, and contacts the feedstock oil from the feedstock oil inlet 102 to produce a first catalytic cracking reaction in the reaction zone II. The carbonized catalyst and the oil and gas generated by the reaction flow upward, enter the outlet zone III, and enter the oil-agent separation device 201 through the outlet 104.

[0169] The pre-lifting gas enters the coker from the bottom of the coker 300 through the pre-lifting gas inlet 301, and the high-temperature regenerated catalyst from the regenerator enters the lower part of the coker 300 through the catalyst inlet 303, mixes with the pre-lifting gas and moves upward, contacts with the coking crude oil from the fuel oil inlet 302, and enters the coker together to cause a coking reaction; the catalyst with carbon and the oil and gas generated by the reaction flow upward, mix with the C4 hydrocarbon fraction or the C5-C6 light gasoline fraction introduced through the fuel oil inlet 305, and enter the dense phase sedimentation section 205 through the outlet area 304.

[0170] The reaction oil and gas separated by the oil-agent separation device 201 enter the gas collecting chamber 202 and are introduced into the product separation system through the oil and gas pipeline 203; the separated regenerated catalyst enters the dense phase settling section 205 of the settler, contacts the C4 hydrocarbon fraction or the C5-C6 light gasoline fraction introduced through the fuel oil inlet 305, and undergoes a second cracking reaction. The regenerated catalyst enters the regenerator 500 after the reaction; the oxygen-containing gas from the oxygen-containing gas inlet 501 enters the regenerator after passing through the gas distributor 502, contacts the coke-carrying catalyst, undergoes a complete combustion reaction, and completely releases heat. Part of the regenerated catalyst returns to the catalytic cracking reactor for recycling, and part of the catalyst returns to the coke generator for recycling. The regenerated flue gas is recovered by the cyclone separator 503 to remove the entrained catalyst and is sent to the subsequent energy recovery system through the flue gas outlet 504.

[0171] Example

[0172] The following examples further illustrate the present invention but are not intended to limit the present invention. The catalyst used in the experiments was an industrial catalyst with the trade name NCC. The cracking reaction feedstock was Yanshan straight-run naphtha obtained from the Yanshan Petrochemical atmospheric and vacuum unit. The coke feedstock was catalytic diesel obtained from the Anqing Petrochemical catalytic cracking unit. The properties of these two feedstocks are shown in Table 1.

[0173] Example 1

[0174] exist Figure 3 The system was tested, in which

[0175] The structure of the catalytic cracking reactor used is as follows:

[0176] The total height of the reactor is 10 meters, of which the pre-lifting zone is 2 meters and the inner diameter is 0.2 meters; the reaction zone is 5 meters high, the inner diameter of the top cross section is 0.2 meters, and the inner diameter of the bottom cross section is 0.3 meters; the outlet zone is 3 meters high and has an inner diameter of 0.2 meters.

[0177] The coke generator 300 used includes:

[0178] Pre-lifting zone I, with a length of 1 meter and an inner diameter of 0.2 meters;

[0179] Coke-generating reaction zone II is a turbulent bed reactor with a length of 3 meters and an inner diameter of 0.4 meters;

[0180] The outlet zone III has a length of 2 meters and an inner diameter of 0.2 meters.

[0181] The coke generator is provided with a pre-lift gas inlet 301 , a regenerated catalyst inlet 303 , and a fuel oil inlet 302 in sequence from bottom to top, and all are located at the lower part of the coke generator 300 .

[0182] The distance between the fuel oil inlet 302 and the bottom of the coke generator is independently 10% of the height of the coke generator.

[0183] A cracking reaction test of straight-run naphtha was carried out in a catalytic cracking reactor. Preheated feedstock oil was introduced from the lower part of the cracking reactor, contacted with the regenerated catalyst from the regenerator, and a catalytic cracking reaction was carried out from bottom to top to obtain an oil-agent mixture of reaction products and the regenerated catalyst. The oil-agent mixture entered a cyclone separator from the reactor outlet, and the reaction products and the regenerated catalyst were quickly separated. The reaction products were cooled and collected.

[0184] The pre-lifting medium nitrogen enters the lower part of the coking vessel, mixes with the regenerated catalyst, and then flows upward. The mixture of Anqing slurry oil (coking raw material) and atomized medium (water vapor) enters the coking vessel through the fuel oil inlet, contacts the hot regenerated catalyst, and undergoes a coking reaction to obtain a mixture of reaction products and an oil agent with carbonized catalyst. The C5-C6 light gasoline fraction is injected into the outlet area of ​​the coking vessel and sent together with the oil agent mixture into the dense phase settling section below the settler.

[0185] The spent catalyst and the charred catalyst enter the dense phase settling section under gravity, where steam strips the hydrocarbon products adsorbed on the spent catalyst. The stripped spent catalyst then enters the regenerator, where it is regenerated by contact with air. The regenerated catalyst is then returned to the catalytic cracking reactor and the coke generator for recycling. The regenerated catalyst recycled to the catalytic cracking reactor accounts for 85% by weight of the total regenerated catalyst, while the regenerated catalyst recycled to the coke generator accounts for 15% by weight of the total regenerated catalyst. The operating conditions and product distribution are listed in Table 2.

[0186] From the results in Table 2, it can be seen that the ethylene yield is 24.95 wt%, the propylene yield is 25.13 wt%, the total selectivity of ethylene and propylene is 57.88%, the methane yield is 10.10%, the methane selectivity is 11.67%, and the coke yield is 5.97%.

[0187] Comparative Example 1

[0188] according to Figure 3 The experiment was conducted with reference to the process of Example 1, except that the coke generator was not turned on in Comparative Example 1, that is, the catalyst was regenerated as follows:

[0189] The spent catalyst enters the stripping section of the settler under gravity, where steam strips the hydrocarbon products adsorbed on the spent catalyst. The stripped catalyst then enters the regenerator, where it is regenerated by contact with air. Simultaneously, fuel oil is injected into the regenerator bed, releasing heat and burning it to replenish the regenerator's heat. The regenerated catalyst is then returned to the reactor for recycling. The operating conditions and product distribution are listed in Table 2.

[0190] From the results in Table 2, it can be seen that the ethylene yield is 23.81 wt%, the propylene yield is 24.36 wt%, the total selectivity of ethylene and propylene is 56.57%, the methane yield is 10.54%, the methane selectivity is 12.38%, and the coke yield is 3.7%.

[0191] It can be seen from the results of the above examples that the catalytic cracking reaction system of the present application can not only reduce the methane yield and improve the selectivity of ethylene and propylene, but also can produce coke with high selectivity, provide a heat source for the regenerator from the reaction system, have no effect on the regeneration system, and help maintain the physical and chemical properties of the catalyst.

[0192] In the description of this 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 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 direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on this application.

[0193] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0194] The present application has been described above in conjunction with preferred embodiments, but these embodiments are merely exemplary and serve only as an illustrative example. On this basis, various replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

[0195] Table 1 Properties of cracking reaction raw materials and coke raw materials

[0196] Straight-run naphtha Anqing slurry <![CDATA[Density at 20 °C, kg / m 3 > 752.5 1068.6 Refractive index at 70℃ 1.6361 <![CDATA[Viscosity at 100°C, millimeters 2 / second]]> 11.5 Carbon residue, % (weight) 0 4.79 Carbon content, % (weight) 87.47 91.22 Hydrogen content, % (weight) 14.53 8.06 Sulfur content, % (weight) 0.014 0.331 Nitrogen content, mg / kg 1.2 2100 Basic nitrogen, mg / kg / 86 Distillation range, ℃ 5% (volume) / 364.5 10% (volume) 90.9 373.2 30% (volume) 121.7 400.6 50% (volume) 145.8 425.6 70% (volume) 167.3 464.8 95% (volume) 197.5 /

[0197] Table 2 Operating conditions and results of Examples and Comparative Examples

[0198] Example Comparative Example Cracking reactor conditions Cracking reactor outlet temperature, ℃ 670 670 Weight ratio of catalyst to raw material feed 30：1 30：1 Reaction time, seconds 2.1 2 Weight ratio of water vapor to raw material feed 0.3 0.3 Coke generator conditions Coke generator outlet temperature, ℃ 650 Weight ratio of catalyst to coke raw material feed 30 Reaction time, seconds 5 Weight ratio of water vapor to coke raw material feed 0.3 The proportion of raw coke to the raw material feed of cracking reactor, % 35 The proportion of C5-C6 light gasoline fraction feed to the cracking reactor raw material feed, % 5 Regenerator conditions Temperature in regenerator, ℃ 720 720 The proportion of oil slurry feed in the regenerator to the feed of the cracking reactor, % 30 Product yield, weight % dry gas 40.53 40.13 Of which methane 10.10 10.54 Of which ethylene 24.95 23.81 Liquefied gas 38.39 39.00 Of which propylene 25.13 24.36 pyrolysis gasoline 13.48 14.85 Cracking heavy oil 1.63 2.30 coke 5.97 3.7 total 100.00 100.00 Methane selectivity, % 11.67 12.38 Total selectivity of ethylene and propylene, % 57.88 56.57

Claims

1. A light oil catalytic cracking method, the method comprising: 1) introducing preheated light oil from the lower portion of a catalytic cracking reactor, contacting it with a regenerated catalyst from a regenerator, and performing a first catalytic cracking reaction from bottom to top to obtain a first reaction product and a first regenerated catalyst, wherein the catalytic cracking reactor comprises a reaction zone, wherein the reaction zone comprises at least one reduced diameter reaction section, wherein the reduced diameter reaction section is a hollow cone having a substantially circular cross-section and open bottom and top ends, and wherein the inner diameter of the reduced diameter reaction section decreases continuously or discontinuously from bottom to top; 2) introducing the coke-forming raw material into the coke-forming reaction zone of the coke maker, contacting it with the regenerated catalyst from the regenerator and carrying out a coke-forming reaction to obtain a coke-forming oil agent, wherein the coke-forming reaction zone is a bubbling fluidized bed or a turbulent fluidized bed, and the coke-forming oil agent comprises the carbon-bearing catalyst obtained by the coke-forming reaction; mixing the coke-forming oil agent with a C4 hydrocarbon fraction and / or a C5-C6 light gasoline fraction at one or more locations in the outlet zone of the coke maker, and introducing the coke-forming oil agent into the dense phase settling section of the settler for a second catalytic cracking reaction to obtain a second reaction product and a second catalyst to be regenerated; 3) transporting the settler catalyst from the settler to a regenerator for charring and regeneration, and recycling the regenerated catalyst, wherein the settler catalyst includes a first catalyst to be regenerated and a second catalyst to be regenerated; 4) introducing the first reaction product and the second reaction product into a separation system for separation.

2. The method according to claim 1, wherein The light oil includes gaseous hydrocarbons and light distillate oil.

3. The method according to claim 2, wherein: The properties of the light oil meet one, two, three or four of the following indicators: density at 20°C is less than 860 kg / m3, residual carbon is 0-0.5% by weight, total aromatic hydrocarbon content is 0%-30% by weight, and final distillation point is less than 360°C.

4. The method according to claim 1, wherein The conditions of the first catalytic cracking reaction include: a reaction temperature of 510-750°C, a reaction time of 0.5-10 seconds, a catalyst-to-oil weight ratio of 10:1 to 50:1, a weight ratio of pre-lift gas to feed oil of 0.05:1 to 2.0:1, a catalyst density of 20-100 kg / m3, a linear velocity of 4-18 m / s, and a reaction pressure of 130-450 kPa.

5. The method according to claim 1, wherein The coking reaction conditions include: a reaction temperature of 460-650°C, a reaction time of 1-20 seconds, a catalyst-oil weight ratio of 3:1 to 30:1, a weight ratio of pre-lift gas to coking raw material of 0.01:1 to 0.05:1, a linear velocity of 0.2-0.8 m / s, and a catalyst particle density of 300-700 kg / m3.

6. The method according to claim 1, wherein The conditions of the second catalytic cracking reaction include: reaction temperature of 490-730°C, weight hourly space velocity of 0.5-20 hours -1 .

7. The method according to claim 1, wherein The coke raw material is selected from the cracked heavy oil or secondary processed distillate oil produced by the device, or a mixture thereof.

8. The method according to claim 7, wherein: The secondary processed distillate oil is selected from a mixture of one or more of catalytic cracking diesel, catalytic cracking diesel, catalytic cracking slurry, catalytic cracking slurry, coker gasoline, coker diesel and coker gas oil.

9. The method according to claim 6, wherein: The raw material for coking is the cracking heavy oil produced by the device.

10. A catalytic cracking reaction-regeneration system for implementing the light oil catalytic cracking method according to any one of claims 1 to 9, comprising: Catalytic cracking reactor, coke generator, Oil separation equipment, settler, and Regenerator, The catalytic cracking reactor comprises, from bottom to top, the following components: optional pre-lift zone; A reaction zone, the reaction zone comprising at least one reduced-diameter reaction section, the reduced-diameter reaction section being in the form of a hollow cone with a substantially circular cross-section and open bottom and top ends, the inner diameter of which decreases continuously or discontinuously from bottom to top; and export zone; wherein the optional pre-lifting zone is connected to the bottom end of the reaction zone, the top end of the reaction zone is connected to the outlet zone, and at least one raw material feed port is provided on the optional pre-lifting zone and / or the bottom end of the reaction zone; The inner diameter of the cross section of the bottom end of the reaction zone is greater than or equal to the inner diameter of the cross section of the optional pre-lift zone, and the inner diameter of the cross section of the top end is equal to or smaller than the inner diameter of the cross section of the optional pre-lift zone and the inner diameter of the cross section of the outlet zone; the regenerated catalyst inlet is provided at the bottom of the reaction zone and / or the optional pre-lift zone; The catalytic cracking reactor is coaxially arranged with the settler, and the oil-agent separation device is accommodated inside the settler. The outlet area of ​​the catalytic cracking reactor is in communication with the oil-agent separation device, so that the oil from the catalytic cracking reactor enters the oil-agent separation device and is separated into a first reaction product and a first spent catalyst. The lower part of the settler is provided with a dense phase settling section, and the dense phase settling section of the settler is provided with a catalyst outlet; the catalyst outlet of the settler is connected to the regenerator, so that the settler catalyst in the settler is transported to the regenerator; The coke generator comprises, from bottom to top, Pre-lift area, a coke-forming reaction zone, wherein the coke-forming reaction zone is a bubbling fluidized bed or a turbulent fluidized bed, and Export Zone, wherein the top of the pre-lifting zone is connected to the coke-generating reaction zone, and the top of the coke-generating reaction zone is connected to the outlet zone; The coke maker is provided with at least two fuel oil feed ports, wherein at least one fuel oil inlet is provided upstream of the coke making reaction zone of the coke maker for introducing coke making raw materials, and at least one fuel oil inlet is provided downstream of the coke making reaction zone of the coke maker for mixing C4 hydrocarbon fraction and / or C5-C6 light gasoline fraction; The coke generator is arranged outside the settler, and the outlet area of ​​the coke generator is connected to the dense phase settling section of the settler, so that the material of the coke generator enters the dense phase settling section of the settler; The regenerator is provided with a first regenerated catalyst outlet and a second regenerated catalyst outlet, wherein the first regenerated catalyst outlet is connected to the regenerated catalyst inlet of the catalytic cracking reactor, so that at least a portion of the regenerated catalyst is circulated back to the catalytic cracking reactor; The bottom end of the pre-lifting zone of the coke maker and / or the bottom end of the coke forming reaction zone is configured to communicate with the second regenerated catalyst outlet of the regenerator, so that at least a portion of the regenerated catalyst of the regenerator is transported to the coke maker.

11. The catalytic cracking reaction-regeneration system according to claim 10, wherein: The ratio of the inner diameter to the height of the pre-lift zone of the catalytic cracking reactor is 0.02-0.4:1; The ratio of its height to the total height of the catalytic cracking reactor is 0.01:1 to 0.2:1; and / or, the ratio of the inner diameter of the bottom cross section of the reaction zone of the catalytic cracking reactor to the total height of the catalytic cracking reactor is 0.01:1 to 0.5:1, and the ratio of the total height to the total height of the catalytic cracking reactor is 0.15:1 to 0.8:1; And / or, the ratio of the inner diameter to the height of the cross section of the outlet zone of the catalytic cracking reactor is 0.01-0.3:1, and the ratio of the height to the total height of the catalytic cracking reactor is 0.05:1 to 0.5:

1.

12. The catalytic cracking reaction-regeneration system according to claim 10, characterized in that: The reaction zone of the catalytic cracking reactor includes 1 to 3 reduced diameter reaction sections.

13. The catalytic cracking reaction-regeneration system according to claim 12, characterized in that: The reduced diameter reaction section of the catalytic cracking reactor is in the form of a hollow truncated cone, and its longitudinal section is an isosceles trapezoid; the ratio of the inner diameter of its top cross-section to the height of the reduced diameter reaction section is independently 0.005-0.3:1, the ratio of the inner diameter of the bottom cross-section to the height of the reduced diameter reaction section is independently 0.015-0.25:1, and the ratio of the inner diameter of the bottom cross-section to the inner diameter of the top cross-section is independently greater than 1.2 and less than or equal to 10; the ratio of the height of the reduced diameter reaction section to the total height of the catalytic cracking reactor is independently 0.15:1 to 0.8:

1.

14. The catalytic cracking reaction-regeneration system according to claim 12, characterized in that: The pre-lifting zone and the reaction zone of the catalytic cracking reactor are connected by a first connecting section, the longitudinal section of the first connecting section is an isosceles trapezoid, and the outward inclination angle α of the side of the isosceles trapezoid is 5-85 o .

15. The catalytic cracking reaction-regeneration system according to claim 10, characterized in that: The coke-generating reaction zone is in the shape of a hollow cylinder, and its aspect ratio is 20:1 to 2:

1.

16. The catalytic cracking reaction-regeneration system according to claim 15, characterized in that: The pre-lifting area of ​​the coke generator is a hollow cylinder with an aspect ratio of 10:1-2:1; The outlet area of ​​the coke generator is a hollow cylinder with a length-to-diameter ratio of 30:1-5:

1.

17. The catalytic cracking reaction-regeneration system according to claim 16, characterized in that: The ratio of the inner diameters of the pre-lifting zone of the coke generator, the coke generating reaction zone of the coke generator, and the outlet zone of the coke generator is 1:2:1 to 1:10:2.

Images