Fluid catalytic cracking and regeneration apparatus and its application

Abstract

The present disclosure is a fluid catalytic cracking regeneration apparatus and its application. The fluid catalytic cracking regeneration apparatus includes a coke supply device, a regenerator, and an external catalyst circulation pipe, the outlet of the coke supply device is in fluid communication with the inlet of the regenerator, the external catalyst circulation pipe connects the lower part of the regenerator with the coke supply device to return a part of the catalyst in the regenerator to the coke supply device, the coke supply device is provided with an inlet for used catalyst, an inlet for oxygen-poor gas, and an inlet for fuel oil, the inlet for oxygen-rich gas is located at the bottom of the regenerator, and the inlet for fuel oil is located downstream of the inlet for used catalyst along the flow direction of the stream. When the regenerator is used for a fluid catalytic cracking reaction with low coke generation, not only can the heat balance of the reaction-regeneration process be realized, but also the temperature rise of the catalyst during the coke burning process in the regenerator can be uniform without local hot spots, so that the physical and chemical properties of the catalyst are not damaged.

Description

[Technical Field]

[0001] The present invention relates to the technical field of fluid catalytic cracking, and in particular to a fluid catalytic cracking regenerator and the use thereof. [Background Art]

[0002] The fluid catalytic cracking reaction process is a self-heat balance process. The large amount of high-level energy released during the catalytic coke combustion regeneration process can exactly meet the low-level energy required for the cracking reaction. The catalyst circulating between the reactor and the regenerator has a sufficient amount and heat capacity such that the catalyst can function as an active site for the reaction and as a heat carrier for transferring heat energy. The catalyst flows between the reactor and the regenerator, continuously acquiring heat from one end and supplying heat to the other end. Establishment of heat balance requires certain conditions, based on which it is guaranteed that the reaction and regeneration reach predetermined temperatures. For industrial catalytic cracking units, the heat balance between the reactor and the regenerator is based on the fact that the reaction generates a sufficient amount of coke. This coke is combusted during the regeneration process to release heat for use in the reaction.

[0003] With the development of petroleum refining processes, particularly the increasing heaviness / degradation of crude oil and the improvement of petroleum product quality, the hydrogenation process has become more widely used. When hydrogenated heavy oil is used as a catalytic cracking raw material, the structure and quality of the product are significantly improved, but the catalytic cracking unit itself does not produce enough coke, resulting in a shortage of heat supply. In addition, catalytic cracking technologies that primarily produce light olefins have a high conversion rate and temperature, requiring a large amount of heat. The amount of heat required for the reaction is greater than that of conventional fluid catalyst regenerators and other catalytic conversion methods, and the resulting coke cannot meet the heat balance requirements of the reaction-regeneration system. If coke production is insufficient during the reaction, fuel oil is usually supplied to the regenerator to provide the heat necessary for the reaction. However, since catalytic cracking uses a catalyst with molecular sieves as the active ingredient, the localized high temperatures generated by the combustion of fuel oil in the regenerator gradually remove aluminum from the molecular sieve skeleton, resulting in irreversible damage to the catalyst. Prior art has not fundamentally resolved the issue of how high-temperature hot spots generated by the localized combustion of additional fuel oil affect the catalyst skeleton structure and reaction performance. [Overview of the project]

[0004] The object of the present invention is to provide a fluid catalytic cracking regeneration apparatus and a method suitable for maintaining heat balance that can solve the problem of heat balance in catalytic cracking reactions while suppressing coke generation, and without affecting the physical and chemical properties of the catalyst.

[0005] To achieve the above objectives, in one embodiment, the present invention provides a fluid catalytic cracking regeneration apparatus. The fluid catalytic cracking regeneration apparatus comprises a coke replenishment device, a regenerator, and an external catalyst circulation pipe, wherein the outlet of the coke replenishment device is in fluid communication with the inlet of the regenerator, and the external catalyst circulation pipe connects the bottom of the regenerator to the coke replenishment device in order to return a portion of the catalyst in the regenerator to the coke replenishment device, the coke replenishment device is provided with an inlet for spent catalyst, an inlet for low oxygen gas, and an inlet for fuel oil, wherein the inlet for rich oxygen gas is located at the bottom of the regenerator, and the fuel oil inlet is located downstream of the spent catalyst inlet along the direction of the flow of the stream.

[0006] In another embodiment, the present invention provides a catalytic cracking system including a catalytic cracking reactor and a fluid catalytic cracking regeneration apparatus according to the present invention.

[0007] In yet another embodiment, a method for regenerating a catalyst using a fluid catalytic cracking regeneration apparatus according to the present invention is provided, comprising the following steps: 1) A step of bringing a spent catalyst into contact with fuel oil and oxygen-deficient gas in a coke replenishment device to carry out a coke formation reaction and a partial coke combustion reaction to obtain a partially coking catalyst; and 2) A step of bringing a partially coking catalyst into contact with oxygen-rich gas in a regenerator and carrying out a complete combustion reaction to obtain a regenerated catalyst.

[0008] The regeneration apparatus according to the present invention has a simple structure and is easy to implement. It can be implemented by adaptively modifying the regeneration equipment of existing industrial units, making it highly applicable and particularly suitable for catalytic cracking units that primarily target petrochemical raw materials such as light olefins. Not only can it fundamentally solve the problem of heat balance in reaction-regeneration systems, but it can also reduce catalyst and hardware damage caused by conventional fuel oil injection modes, saving catalyst costs and improving the economic benefits of refineries. When the regeneration apparatus and method according to the present invention are used in fluid catalytic cracking reactions with low coke generation, it can not only achieve heat balance in the reaction-regeneration process, but also ensure a uniform temperature rise in the catalyst during the coke combustion process in the regeneration unit without localized hot spots, and as a result, the physical and chemical properties of the catalyst are not damaged.

[0009] Other features and advantages of the present invention will be described in detail in the following detailed description. The accompanying drawings, which constitute part of this specification, are intended to provide a further understanding of the invention and should not be considered limiting. The invention can be interpreted by reference to the drawings in conjunction with the following detailed description. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a preferred embodiment of the fluid catalytic cracking and regeneration apparatus provided in the present invention. [Figure 2] This is a schematic diagram of another preferred embodiment of the fluid catalytic cracking and regeneration apparatus provided in the present invention. [Modes for carrying out the invention]

[0011] Specific embodiments of the present invention will be described in detail below, in conjunction with the attached drawings. Please understand that the specific embodiments described herein are intended solely to illustrate and illustrate the present invention and are not intended to limit it.

[0012] As used herein, the term “exemplary” means “serving as an example, embodiment, or explanatory example.” Embodiments described herein as “exemplary” are not necessarily construed to be preferable or advantageous to other embodiments. Various aspects of the embodiments are illustrated in the drawings, which are not necessarily drawn to scale unless otherwise indicated.

[0013] Furthermore, the technical features relating to the different embodiments of the present invention described below can be combined with each other, insofar as they do not contradict each other.

[0014] The specific numerical values ​​disclosed herein (including the endpoints of numerical ranges) should be understood not to be limited to the exact value of the numerical value, but to include all possible values ​​close to the exact value, for example, within ±5% of the exact value. Furthermore, with respect to the disclosed numerical ranges, one or more new numerical ranges can be obtained by any combination of the endpoint values ​​of the range, the endpoint values ​​and specific point values ​​within the range, and each specific point value, and such new numerical ranges should also be considered to be specifically disclosed herein.

[0015] In this invention, the terms "upstream" and "downstream" are based on the direction of the reaction stream. For example, if the reaction stream flows from bottom to top, "upstream" refers to the lower position and "downstream" refers to the upper position.

[0016] In this specification, terms such as "up," "down," "inside," "outside," "front," "back," "left," and "right" indicate orientation or positional relationships based on the operating state of the present invention, and are used solely for the convenience and simplification of explanation. They do not indicate or suggest that the referenced device or element must have a specific orientation, be configured in a specific orientation, or operate in a specific orientation, and should therefore not be construed as limiting the present invention.

[0017] In this specification, the terms “mounted,” “coupled,” and “connected” should be interpreted broadly unless otherwise explicitly specified or limited. The specific meanings of these terms in the present invention can be understood on a case-by-case basis by those skilled in the art.

[0018] Unless otherwise specified, terms used herein have the same meaning as those generally understood by those skilled in the art. If a term is defined herein and that definition differs from the generally understood meaning of those skilled in the art, the definition herein shall prevail.

[0019] As described above, in a first embodiment, the present invention provides a fluid catalytic cracking regeneration apparatus comprising a coke replenishment device, a regenerator, and an external catalyst circulation pipe, wherein the outlet of the coke replenishment device is in fluid communication with the inlet of the regenerator, and the external catalyst circulation pipe connects the bottom of the regenerator to the coke replenishment device in order to return a portion of the catalyst in the regenerator to the coke replenishment device, the coke replenishment device being provided with an inlet for spent catalyst, an inlet for low oxygen gas, and an inlet for fuel oil, wherein the inlet for rich oxygen gas is located at the bottom of the regenerator, and the fuel oil inlet is located downstream of the spent catalyst inlet along the direction of the flow of the stream.

[0020] According to the present invention, the regenerator can have the structure of a conventional regenerator, except that it is necessary to place an opening at the bottom of the regenerator and connect the outlet of the coke replenishment device to the opening, that is, to fluidly communicate the outlet of the coke replenishment device with the inlet of the regenerator and allow the stream originating from the coke replenishment device to flow into the regenerator.

[0021] In the fluid catalytic cracking regeneration apparatus according to the present invention, one or more, preferably one to three, rich oxygen gas inlets are arranged on the side wall of the regenerator for injecting rich oxygen gas into the regenerator, and these inlets are used to regenerate the catalyst entering the regenerator. Preferably, a gas distributor (also referred to as a main air distributor in the present invention) is further arranged at the bottom of the regenerator, thereby sending the rich oxygen gas injected from the rich oxygen gas inlets into the regenerator through the gas distributor. According to the present invention, the gas distributor may be a main air distributor well known to those skilled in the art. For example, the main air distributor may consist of a distribution plate and a distribution pipe. Preferably, the distribution pipe is an annular distribution pipe or a dendritic distribution pipe.

[0022] In some specific embodiments, the regenerator is in fluid communication with a gas-solid separator, so that the regenerated exhaust gas produced by the regenerator is introduced into an energy recovery system after being separated by the gas-solid separator and reused via a regenerated exhaust gas line. In the present invention, the gas-solid separator may be an apparatus well known to those skilled in the art. For example, the gas-solid separator may include a cyclone separator.

[0023] In some specific embodiments, the regenerator is further provided with an outlet for the regenerated catalyst. This outlet is used to discharge the regenerated high-temperature regenerated catalyst from the regenerator and reuse it in the reaction.

[0024] In the fluid catalytic cracking regenerator according to the present invention, a spent catalyst at a relatively low temperature (generally lower than 600°C) is first brought into contact with fuel oil and oxygen-lean gas in a coke replenishing device, to undergo a coke formation reaction and a partial coke combustion reaction to obtain a partially coked catalyst. Then the partially coked catalyst is sent into a regenerator, where it fully releases coke combustion heat under the action of a high temperature and oxygen-rich gas, to supply the heat required for the reaction. For a catalytic cracking reaction process with low coke generation, the regenerator according to the present invention can not only solve the heat balance problem of the reaction-regeneration system, but also alleviate the coke combustion environment of the catalyst, achieve a gentle temperature rise of the catalyst, thereby maximizing the protection of the physical and chemical properties of the catalyst. In contrast, when a regenerated catalyst at a relatively high temperature (usually 660°C or higher) is brought into contact with fuel oil, the carbon combustion rate increases sharply even under an oxygen-lean environment, heat is released through the combustion reaction with oxygen, making it difficult to maintain the morphology of coke on the catalyst surface.

[0025] In a second aspect, the present invention provides a catalytic cracking system comprising a catalytic cracking reactor and a fluid catalytic cracking regenerator according to the present invention.

[0026] According to the present invention, the catalytic cracking system may comprise 1 or more, preferably 1 to 3 catalytic cracking reactors. The fluid catalytic cracking regenerator according to the present invention may be connected to 1 or more catalytic cracking reactors, whereby the spent catalyst from 1 or more catalytic cracking reactors is sent into the regenerator according to the present invention for regeneration, and the regenerated catalyst is recycled to 1 or more catalytic cracking reactors for reuse.

[0027] In some specific embodiments, the catalytic cracking system further comprises an oil separation device, a stripping device, and optionally a reaction product separation device.

[0028] According to the present invention, the catalytic cracking reactor, oil separation device, stripping device, reaction product separation device, etc., may all be devices well known to those skilled in the art, and the connections between these devices can also be made in a manner well known to those skilled in the art. For example, the oil separation device may include a cyclone separator and an outlet quick separator. In some specific embodiments, the oil separation device includes settlers located at high and low levels, respectively, coaxially or in parallel with the catalytic cracking reactor.

[0029] In a third embodiment, a method for regenerating a catalyst using a fluid catalytic cracking regeneration apparatus according to the present invention is provided, comprising the following steps: 1) A step of bringing a spent catalyst into contact with fuel oil and oxygen-deficient gas in a coke replenishment device to carry out a coke formation reaction and a partial coke combustion reaction to obtain a partially coking catalyst; and 2) A step of bringing a partially coking catalyst into contact with oxygen-rich gas in a regenerator and carrying out a complete combustion reaction to obtain a regenerated catalyst.

[0030] According to the present invention, the oxygen-depleted gas can be selected from the group consisting of air, nitrogen, water vapor, mixtures thereof, or mixtures thereof with oxygen. Preferably, the oxygen content of the oxygen-depleted gas is 1 to 20% by volume, more preferably 5 to 10% by volume.

[0031] According to the present invention, the fuel oil may be selected from the group consisting of a direct fraction, a secondary processed fraction, or a combination thereof. Preferably, the secondary processed fraction may be selected from the group consisting of catalytic cracking diesel, catalytic cracking slurry, coker gasoline, coker diesel, coker light oil, or a combination thereof.

[0032] According to the present invention, the oxygen content of the oxygen-rich gas is preferably 21 to 100% by volume, more preferably 21 to 85% by volume. For example, the oxygen-rich gas may be air.

[0033] In a preferred embodiment, the temperature of the spent catalyst in step 1) is 480 to 650°C, preferably 540 to 600°C.

[0034] In some specific embodiments, the temperature inside the regenerator is 620-800°C, preferably 650-750°C, the apparent linear velocity of the gas is 0.2-1.0 m / s, preferably 0.3-0.8 m / s, and the average residence time of the catalyst is 0.5-10 minutes, preferably 1-5 minutes.

[0035] The fluid catalytic cracking regeneration apparatus, catalytic cracking system, and catalyst regeneration method according to the present invention are suitable for various catalytic cracking reaction-regeneration systems in which coke production is insufficient, such as reactions that produce light olefins by catalytic cracking of petroleum hydrocarbons and oxygen-containing hydrocarbons, and in particular reactions that produce light olefins by catalytic cracking of light hydrocarbons or light fractions.

[0036] For example, light hydrocarbons or light fractions may be gaseous hydrocarbons, petroleum hydrocarbons with a distillation range of 25-350°C, oxygen-containing compounds, biomass, or fractions of waste plastic-derived oil; gaseous hydrocarbons may be selected from the group consisting of saturated liquefied gas, unsaturated liquefied gas, C4 fraction, or combinations thereof; petroleum hydrocarbons may be selected from primary-treated straight-run naphtha, straight-run kerosene, straight-run diesel, or combinations thereof; and secondary-treated supernatant oil, raffinate oil, C4 fraction, hydrocracked light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, fluid catalytic cracked light gasoline, hydrogenated gasoline, hydrogenated diesel, or combinations thereof.

[0037] The fluid catalytic cracking regeneration apparatus, catalytic cracking system, and catalyst regeneration method according to the present invention can have various specific embodiments depending on the specific structure of the coke supply device used. Two particularly preferred embodiments are described below.

[0038] First type of preferred embodiment In a first preferred embodiment of the fluid catalytic cracking regeneration apparatus according to the present invention, an external catalyst circulation pipe connects the lower part of the regeneration apparatus to the lower part of the coke replenishment device, and an inlet for oxygen-deficient gas, a connection port between the external catalyst circulation pipe and the coke replenishment device, an inlet for spent catalyst, and an inlet for fuel oil are sequentially arranged on the coke replenishment device along the direction of flow of the stream.

[0039] In the first type of preferred embodiment, an external catalyst circulation pipe allows a portion of the high-temperature regenerating catalyst in the regenerator to flow into the lower part of the coke replenishment device. This portion of the high-temperature regenerating catalyst in the regenerator can be used to heat the spent catalyst in the coke replenishment device when the temperature of the spent catalyst from the reactor is low, thereby contributing to the effective progress of the coke production reaction of fuel oil.

[0040] In the first type of preferred embodiment, the coke replenishment device may be a high-speed fluidized bed. Preferably, the coke replenishment device is in the form of a hollow cylinder having a length-to-diameter ratio of 30:1 to 3:1, preferably 20:1 to 5:1.

[0041] In the first type of preferred embodiment, the coke replenishment device is equipped with a spent catalyst inlet, a connection port for the external catalyst circulation pipe, a hypoxic gas inlet, and a fuel oil inlet, all located at different heights of the coke replenishment device. Preferably, the coke replenishment device is equipped with the hypoxic gas inlet, the connection port for the external catalyst circulation pipe, the spent catalyst inlet, and the fuel oil inlet in order from bottom to top, all located in the lower middle section of the coke replenishment device, i.e., at a distance of 50% or less from the bottom of the coke replenishment device.

[0042] In the first type of preferred embodiment, one or more, preferably one to three, oxygen-depleted gas inlets may be located at the bottom of the coke replenishment device. Preferably, the oxygen-depleted gas inlets are located at the bottom of the coke replenishment device. More preferably, a first gas distributor is further located at the bottom of the coke replenishment device, thereby sending the oxygen-depleted gas injected through the oxygen-depleted gas inlets into the coke replenishment device through the first gas distributor. According to the present invention, the first gas distributor may be a distributor well known to those skilled in the art, such as a distribution plate and a distribution pipe. Preferably, the distribution pipe is an annular distribution pipe or a dendritic distribution pipe.

[0043] In the first type of preferred embodiment, the connection port between the external catalyst circulation pipe and the coke replenishment device is located at the bottom of the coke replenishment device, preferably at a distance of 3% to 20%, preferably 5% to 10%, from the bottom of the coke replenishment device.

[0044] In the first type of preferred embodiment, the coke replenishment device may be provided with one or more fuel oil inlets, for example, one, two, three or more, and each of the one or more fuel oil inlets may be independently located at the entrance or lower middle of the coke replenishment device. Preferably, each of the one or more fuel oil inlets is independently located at the lower middle of the coke replenishment device. More preferably, each of the one or more fuel oil inlets is independently located at a distance of 20% to 50%, preferably 25% to 40%, of the height of the coke replenishment device from the bottom of the coke replenishment device.

[0045] In the first type of preferred embodiment, the catalyst distribution plate may be located where the catalyst is delivered to the bottom of the regenerator, for example, at the outlet of a coke replenishment device. According to the present invention, the catalyst distribution plate may be any of the various types of distribution plates commonly used in industry, for example, one or more of the following shapes: plate shape, arch shape, disc shape, ring shape, and umbrella shape. The catalyst distribution plate is effective in uniformly contacting the catalyst with a high-concentration oxygen-rich gas in the axial direction of the regenerator to carry out the coke combustion reaction, thereby improving coke combustion efficiency and suppressing the occurrence of localized hot spots in the catalyst layer.

[0046] In a first type of preferred embodiment, the coke replenishment device is configured to mix injected fuel oil with a catalyst to form coke under low temperature and low oxygen fluidization conditions. The catalyst, having formed coke, is then backmixed within the coke replenishment device having high-speed fluidized bed properties, thereby uniformly distributing the coke over the catalyst and partially burning it, thereby achieving a gradient increase in the catalyst's surface temperature.

[0047] In a first type of preferred embodiment, the regenerator and the coke replenishment device can be arranged coaxially or in parallel at high and low levels, respectively.

[0048] In a first preferred embodiment of a method for regenerating a catalyst according to the present invention, step 1) of the method further includes the following steps: 1a) A step of heating the spent catalyst by mixing it with a regenerated catalyst derived from a regenerator through an external catalyst circulation pipe and bringing it into contact with a low-oxygen gas injected through a low-oxygen gas inlet, thereby carrying out a partial coke combustion reaction; and 1b) A step in which the stream obtained in step 1a) is brought into contact with a mixture of a spray medium and fuel oil injected through a fuel oil inlet to carry out a coke formation reaction and a partial coke combustion reaction to obtain a partial coking catalyst.

[0049] In the first type of preferred embodiment, the logarithmic mean linear velocity of the coke replenishment device is preferably 1.2 to 2.2 m / s.

[0050] In the first type of preferred embodiment, the atomizing medium is preferably nitrogen, and the mass ratio of the atomizing medium to the fuel oil is preferably 1:1 to 1:100.

[0051] In the first type of preferred embodiment, the outlet temperature of the coke replenishment device is preferably 550 to 650°C.

[0052] A first preferred embodiment of the present invention will be further described with reference to the accompanying drawings, but the present invention is not limited thereto.

[0053] In a preferred embodiment, as shown in Figure 1, the fluid catalytic cracking regeneration apparatus according to the present invention includes a coke replenishment device 101 and a regenerator 102, the outlet of the coke replenishment device 101 is in fluid communication with the inlet of the regenerator 102, allowing the stream originating from the coke replenishment device 101 to flow into the regenerator 102. The lower part of the coke replenishment device 101 is also in communication with the lower part of the regenerator 102 through an external catalyst circulation pipe 108, allowing a portion of the high-temperature regeneration catalyst in the regenerator 102 to flow into the coke replenishment device 101, thereby heating the spent catalyst in the coke replenishment device 101 originating from the reactor, and thus achieving optimal energy utilization.

[0054] At the bottom of the coke replenishment device 101 are an inlet 105 for low-oxygen gas and a first gas distributor 106; on the lower side wall of the coke replenishment device 101 are an inlet 107 for spent catalyst and a connection port for the external catalyst circulation pipe 108; and in the middle lower part of the coke replenishment device 101 is an inlet 109 for fuel oil. At the bottom of the regenerator 102 are a second gas distributor (i.e., a main air distributor) 112, and on the bottom side wall are one or more inlets 111 for rich-oxygen gas (i.e., main air inlets) 111, for example, one, two, three, or more.

[0055] Low-oxygen gas is introduced into the coke replenishment device 101 from the bottom of the coke replenishment device 101 through the low-oxygen gas inlet 105. High-temperature regenerated catalyst from the external catalyst circulation pipe 108 is sent to the bottom of the coke replenishment device 101, mixed with the low-oxygen gas, and moves upward, coming into contact with spent catalyst from the spent catalyst inlet 107 to carry out a partial coke combustion reaction. The reaction stream continues to move upward, coming into contact with fuel oil from the fuel oil inlet 109 to carry out coke formation and partial coke combustion reactions. The coking catalyst flows upward and is sent into the regenerator 102 through the catalyst distributor 110, where it comes into contact with rich oxygen gas injected through the rich oxygen gas inlet 111 and the second gas distributor 112 to carry out a complete combustion reaction, thereby completely releasing heat. The regenerated catalyst is discharged from the regenerator through the regenerated catalyst outlet 113 and reused in the reaction. After the regenerated exhaust gas has had its accompanying catalyst separated by the cyclone separator 103, it is sent to the energy recovery system via line 104.

[0056] Second type of preferred embodiment In a second preferred embodiment of the fluid catalytic cracking regeneration apparatus according to the present invention, the coke supply device is provided with a prelift zone, a coke generation zone, and a pre-combustion zone, in order along the direction of flow of the stream, the outlet of the prelift zone is in fluid communication with the inlet of the coke generation zone, the outlet of the coke generation zone is in fluid communication with the inlet of the pre-combustion zone, the outlet of the pre-combustion zone is in fluid communication with the inlet of the regenerator, and an external catalyst circulation pipe connects the lower part of the regenerator to the lower part of the pre-combustion zone; An inlet for used catalyst is located on the side wall of the prelift zone; one or more, preferably one to three, fuel oil inlets are provided, each independently located on the side wall of the prelift zone and / or the side wall of the coke generation zone; and an inlet for hypoxic gas is located on the side wall of the pre-combustion zone.

[0057] In a second preferred embodiment, a portion of the high-temperature regenerating catalyst in the regenerator flows into the lower part of the pre-combustion zone via an external catalyst circulation pipe and is used to heat the coked spent catalyst originating from the coke generation zone. When the coke content on the spent catalyst is relatively high, it is advantageous for the combustion and heat release of the coke on the spent catalyst, thereby achieving a gradient temperature increase of the spent catalyst and avoiding tail combustion phenomena caused by incomplete combustion due to a large amount of coke being introduced into the main combustion zone.

[0058] In a second type of preferred embodiment, the fluid catalytic cracking regeneration apparatus according to the present invention comprises a prelift zone located at the bottom of the fluid catalytic cracking regeneration apparatus, upstream in the flow direction of the spent catalyst within the fluid catalytic cracking regeneration apparatus. A spent catalyst inlet is provided at the bottom of the prelift zone, which is used to transport the spent catalyst from the catalytic cracking reactor to the fluid catalytic cracking regeneration apparatus for regeneration. A prelift medium is introduced from the inlet at the bottom of the prelift zone and is used to lift the introduced spent catalyst upward. The prelift medium used in the prelift zone may be nitrogen, water vapor, or a mixture thereof. Preferably, the prelift zone may be in the form of a hollow cylinder having a certain diameter, and the hollow cylinder may have a length-to-diameter ratio of 30:1 to 3:1, preferably 20:1 to 5:1.

[0059] In a second type of preferred embodiment, the fluid catalytic cracking regeneration apparatus according to the present invention comprises a coke-generating zone positioned above the prelift zone to further rectify the coking catalyst therein to provide a uniform distribution of coke on the catalyst. In some even more preferred embodiments, the coke-generating zone is a pneumatic conveying bed or a high-speed fluidized bed. Preferably, the coke-generating zone is in the form of a hollow cylinder having a certain diameter, which may have a length-to-diameter ratio of 30:1 to 3:1, preferably 20:1 to 5:1.

[0060] In some more preferred embodiments, the ratio of the inner diameter of the coke generation zone to the inner diameter of the prelift zone is 0.2:1 to 0.8:1, preferably 0.3:1 to 0.6:1, and the ratio of the height of the coke generation zone to the height of the prelift zone is 0.5:1 to 1.5:1, preferably 0.8:1 to 1.2:1.

[0061] In some more preferred embodiments, the coke-generating zone and the prelift zone may be connected by a first joint. Preferably, the longitudinal cross-section of the first joint is isosceles trapezoidal (as shown in Figure 2), and the outward inclination angle β of the sides of the isosceles trapezoid is 5 to 85°.

[0062] In a second type of preferred embodiment, one or more, preferably one to three, fuel oil inlets are provided on the side walls of the prelift zone and / or the coke generation zone for injecting fuel oil.

[0063] In some more preferred embodiments, one or more, preferably one to three, fuel oil inlets are independently positioned on the side wall of the prelift zone at a distance of 0% to 15%, preferably 0% to 10%, of the height of the prelift zone from the outlet end of the prelift zone.

[0064] In a more preferred embodiment, one or more, preferably one to three, fuel oil inlets are independently positioned on the side wall of the coke formation zone at a distance of 0 to 15%, preferably 0 to 10%, of the height of the coke formation zone from the bottom of the coke formation zone.

[0065] Fuel oil is injected into the prelift zone and / or coke-making zone, where it is mixed with a catalyst under low temperature and oxygen-free or low-oxygen fluidization conditions to produce coke. The coking catalyst is further refined in the coke-making zone, thereby ensuring a uniform distribution of coke on the catalyst.

[0066] In a second preferred embodiment, the fluid catalytic cracking regeneration apparatus according to the present invention includes a pre-combustion zone, which has one or more, preferably one to three, oxygen-poor gas inlets on its side wall. The pre-combustion zone is arranged so that a coking catalyst flows uniformly into it and comes into contact with an oxygen-containing gas at a relatively low temperature and a relatively high gas linear velocity, thereby partially burning the coke on the catalyst and achieving a gradient increase in the catalyst surface temperature.

[0067] In a more preferred embodiment, one or more, preferably one to three, oxygen-deficient gas inlets are located at the bottom of the pre-combustion zone, and the gas nozzles located at the oxygen-deficient gas inlets are independently positioned at a distance of 5% to 30%, preferably 10% to 20%, of the height of the pre-combustion zone from the bottom of the pre-combustion zone. Preferably, the gas nozzle line has an axial angle α of 5 to 85°, preferably 15 to 75°.

[0068] In a more preferred embodiment, the prelift zone, coke generation zone, and pre-combustion zone may each be in the form of a hollow cylinder and arranged coaxially.

[0069] In a second type of preferred embodiment, the pre-combustion zone is also in communication with a regenerator through an external catalyst circulation pipe. Preferably, the external catalyst circulation pipe is connected to the pre-combustion zone at a distance from the bottom of the pre-combustion zone that is 0-20%, preferably 3-10%, of the height of the pre-combustion zone. Within the regenerator, a portion of the regenerated catalyst is circulated back to the pre-combustion zone through the external catalyst circulation pipe and mixed with the catalyst from the coke-producing zone to raise its temperature.

[0070] In a second type of preferred embodiment, the regenerator and the pre-combustion zone can be arranged coaxially or in parallel at high and low levels, respectively. Preferably, the regenerator, coke-making zone and pre-combustion zone are arranged coaxially.

[0071] In a more preferred embodiment, the pre-combustion zone includes a partial combustion section and an outlet section, where the inner diameter of the partial combustion section is larger than the inner diameter of the outlet section. Preferably, the ratio of the inner diameter of the partial combustion section to the inner diameter of the outlet section is 10:1 to 2:1, and the ratio of the height of the partial combustion section to the height of the outlet section is 10:1 to 2:1.

[0072] In a more preferred embodiment, a catalyst discharge pipe is positioned at the top of the outlet of the pre-combustion zone, and the outlet of the pre-combustion zone is positioned inside the regenerator together with the catalyst discharge pipe, thereby allowing the catalyst originating from the pre-combustion zone to be directly introduced into the regenerator through the catalyst discharge pipe, thereby achieving complete combustion and regeneration within the regenerator. For example, the regenerator may be configured as a conventional catalytic cracking single-stage regenerator, with an opening positioned at its lower part, so that the outlet of the pre-combustion zone, together with the catalyst discharge pipe, is included inside the regenerator through this opening.

[0073] In a second preferred embodiment of the method for regenerating a catalyst according to the present invention, step 1) of the method further includes the following steps: 1a') A step of bringing a coking reaction to obtain a coking catalyst by bringing a spent catalyst introduced through the prelift zone into contact with a mixture of a spray medium and fuel oil injected through the fuel oil inlet of the coke formation zone; and 1b') A step in which the stream obtained in step 1a') is mixed with a regenerated catalyst derived from the regenerator through an external catalyst circulation pipe in the pre-combustion zone, heated, and brought into contact with oxygen-deficient gas injected from the oxygen-deficient gas inlet to carry out a partial coke combustion reaction and obtain a partially coked catalyst.

[0074] In a second type of preferred embodiment, a prelift medium can be injected into the prelift zone to lift the spent catalyst, and the prelift medium used may be nitrogen, water vapor, or a mixture thereof.

[0075] In a second type of preferred embodiment, the fuel oil can be mixed with an atomizing medium to better disperse the fuel oil, and the mixture is injected through an inlet for the fuel oil. Preferably, the atomizing medium is nitrogen. More preferably, the mass ratio of fuel oil to atomizing medium may be 1:1 to 100:1, for example, 1:1 to 50:1, or 1:1 to 20:1. In actual operation, the injection amount of the mixture of atomizing medium and fuel oil is adjusted according to the supply amount of feedstock oil in the reactor connected to the regenerator and is used to control the temperature of the regenerated catalyst after regeneration to 620 to 800°C.

[0076] In a second type of preferred embodiment, the pre-combustion zone preferably has a logarithmic mean linear velocity of 1.2 to 2.2 m / s, and the temperature at the outlet of the pre-combustion zone is preferably 550 to 650°C.

[0077] The present invention is not limited to a second type of preferred embodiment, which will be further described with reference to the accompanying drawings.

[0078] In a preferred embodiment, as shown in Figure 2, the fluid catalytic cracking regeneration apparatus according to the present invention comprises a prelift zone 201, a coke generation zone 202, a pre-combustion zone 203, and a regenerator 204, arranged from bottom to top. A prelift medium inlet 208 is located at the bottom of the prelift zone 201, a used catalyst inlet 209 is located at the lower part, and a fuel oil inlet 210 is located at the upper outlet end. One or more, preferably one to three, oxygen-containing gas inlets 211 are located on the lower side wall of the pre-combustion zone 203. The pre-combustion zone 203 includes a partial combustion section 231 and an outlet section 232, with a catalyst discharge pipe 213 located at the top of the outlet section 232 of the pre-combustion zone, and the outlet section 232 of the pre-combustion zone is located inside the regenerator together with the catalyst discharge pipe 213. A gas distributor 207 is located at the bottom of the regenerator 204, and one or more oxygen-rich gas inlets 214, for example, one, two, three, or more, are located on the side wall of the bottom. The lower part of the regenerator 204 is also in communication with the lower part of the pre-combustion zone 203 via an external catalyst circulation pipe 212.

[0079] The prelift medium is nitrogen, water vapor, or a mixture thereof, and is sent from the bottom of the prelift zone 201 to the fluid catalytic cracking regeneration unit via line 208. Spent catalyst from the spent catalyst inlet 209 is sent to the bottom of the prelift zone 201 and moves upward due to the lifting effect of the prelift medium. Fuel oil and spray medium are injected into the top of the prelift zone 201 through the fuel oil inlet 210, mixed, and come into contact with the catalyst in the coke formation zone 202 to carry out the coke formation reaction. The coking catalyst flows upward and is sent to the pre-combustion zone 203, where it is mixed and heated with the high-temperature regenerating catalyst returned through the external catalyst circulation pipe 212, and comes into contact with the low-oxygen gas introduced from the low-oxygen gas inlet 211 to carry out a partial coking reaction that partially burns the coke on the catalyst. The obtained partial coking catalyst is sent to the regenerator 204 through the discharge pipe 213, where it comes into contact with the rich oxygen gas injected through the rich oxygen gas inlet 214 and the gas distributor 207 to undergo a complete combustion reaction, thereby completely releasing heat. The regenerated catalyst is discharged from the regenerator through the catalyst outlet 215 and reused in the reaction; the regenerated exhaust gas, after the accompanying catalyst is separated by the cyclone separator 205, is sent to the energy recovery system via line 206.

[0080] In some preferred embodiments, the present invention provides the following preferred embodiments: A1. A fluid catalytic cracking and regeneration apparatus suitable for maintaining heat balance, comprising a coke replenishment device and a regenerator, wherein the outlet of the coke replenishment device is in fluid communication with the inlet of the regenerator, allowing a stream originating from the coke replenishment device to flow into the regenerator; The coke replenishment device is provided with an inlet for used catalyst, an inlet for oxygen-deficient gas, and an inlet for fuel oil; The regenerator is provided with an inlet for oxygen-rich gas; The bottom of the coke supply device is in communication with the bottom of the regenerator through an external catalyst circulation pipe, in a fluid catalytic cracking regeneration apparatus.

[0081] A2. The fluid catalytic cracking regeneration apparatus according to item A1, wherein the coke supply device is provided with the oxygen-deficient gas inlet, the connection port for the external catalyst circulation pipe, the spent catalyst inlet, and the fuel oil inlet in that order from bottom to top.

[0082] A3. The fluid catalytic cracking and regeneration apparatus according to item A2, wherein the connection port of the external catalyst circulation pipe is located on the coke supply device at a position where the distance from the bottom of the coke supply device is 5% to 10% of the height of the coke supply device.

[0083] A4. The fluid catalytic cracking and regeneration apparatus described in item A1, wherein the fuel oil inlets are each independently located in the middle or upstream of the coke supply device.

[0084] A5. The fluid catalytic cracking and regeneration apparatus as described in item A1, wherein the fuel oil inlets are independently arranged at positions where the distance from the bottom of the coke supply device is 20% to 50% of the height of the coke supply device.

[0085] A6. The fluid catalytic cracking and regeneration apparatus according to item A1, wherein a first gas distributor is located at the bottom of the coke supply device, thereby sending the oxygen-poor gas injected through the oxygen-poor gas inlet into the coke supply device through the first gas distributor.

[0086] A7. The fluid catalytic cracking regeneration apparatus described in item A1, wherein a catalyst distribution plate is located at the outlet of the coke supply device.

[0087] A8. The fluid catalytic cracking and regeneration apparatus according to item A1, wherein the coke supply device is in the form of a hollow cylinder having a length-to-diameter ratio of 30:1 to 3:1.

[0088] A9. The fluid catalytic cracking regeneration apparatus as described in item A1, wherein a second gas distributor is located at the bottom of the regenerator, thereby sending the rich oxygen gas injected through the rich oxygen gas inlet to the regenerator through the second gas distributor.

[0089] A10. The fluid catalytic cracking regeneration apparatus as described in item A1, wherein the regenerator is in fluid communication with a gas-solid separator, and the regenerated exhaust gas generated by the regenerator is separated by the gas-solid separator and then introduced into the energy recovery system.

[0090] A11. A method for regenerating a catalytic cracking catalyst, carried out in a fluid catalytic cracking regeneration apparatus described in any of items A1 to A10, comprising the following steps: A process in which oxygen-deficient gas is injected into a coke replenishment device through an oxygen-deficient gas inlet, the oxygen-deficient gas is brought into contact with a regenerating catalyst derived from the regenerator and a spent catalyst derived from the reactor, and the spent catalyst is heated to carry out a partial coke combustion reaction; A step of injecting a mixture of spray medium and fuel oil into the coke supply device through a fuel oil inlet, bringing the mixture of spray medium and fuel oil into contact with a catalyst in the coke supply device, carrying out a coke formation reaction and a partial coke combustion reaction to obtain a partial coking catalyst; and The process involves sending the partial coking catalyst to the regenerator, bringing the partial coking catalyst into contact with the rich oxygen gas injected into the regenerator through the rich oxygen gas inlet, and performing a complete combustion reaction to obtain a regenerated catalyst.

[0091] A12. The regeneration method according to item A11, wherein the coke supply device has a logarithmic mean linear velocity of 1.2 m / s to 2.2 m / s, and the oxygen-depleted gas has an oxygen content of 1% to 20%, more preferably 5% to 10%.

[0092] A13. The regeneration method described in item A11, wherein the spraying medium is nitrogen and the mass ratio of the spraying medium to the fuel oil is 1:1 to 1:100.

[0093] A14. The regeneration method according to item A11, wherein the coke supply device has an outlet temperature of 550 to 650°C.

[0094] A15. The regeneration method according to item A11, wherein the oxygen-rich gas in the regenerator has an oxygen content of 21% to 100% by volume, and more preferably, the oxygen-rich gas has an oxygen content of 21% to 85% by volume.

[0095] A16. The regeneration method described in item A11, where the temperature inside the regenerator is 600-800°C.

[0096] A17. A catalytic cracking system including a catalyst regeneration device as described in any one of items A1 to A10.

[0097] B1. A fluid catalytic cracking and regeneration apparatus comprising, in order from bottom to top, a prelift zone, a coke generation zone, a pre-combustion zone, and a regenerator, The outlet of the prelift zone is in fluid communication with the inlet of the coke generation zone, the outlet of the coke generation zone is in fluid communication with the inlet of the pre-combustion zone, the outlet of the pre-combustion zone is in fluid communication with the inlet of the regenerator; and the pre-combustion zone is in communication with the regenerator via an external catalyst circulation pipe; One or more fuel oil inlets are provided on the side walls of the prelift zone and / or the side walls of the coke generation zone; One or more oxygen-poor gas inlets are located on the side wall of the pre-combustion zone; and A fluid catalytic cracking regeneration apparatus in which one or more oxygen-rich gas inlets are located on the side wall of the regenerator.

[0098] B2. The fluid catalytic cracking and regeneration apparatus according to item B1, wherein one or more fuel oil inlets are arranged on the side wall of the prelift zone at a distance of 0% to 15%; preferably 0% to 10% of the height of the prelift zone, respectively, from the outlet end of the prelift zone.

[0099] B3. The fluid catalytic cracking and regeneration apparatus according to item B1, wherein one or more fuel oil inlets are arranged on the side wall of the coke generation zone, each independently from the bottom of the coke generation zone at a distance of 0% to 15%, preferably 0% to 10%, of the height of the coke generation zone.

[0100] B4. The fluid catalytic cracking and regeneration apparatus according to item B1, wherein the oxygen-deficient gas inlet is located at the bottom of the pre-combustion zone, and the oxygen-deficient gas inlet has nozzles that are independently located at a distance of 15% to 30% of the height of the pre-combustion zone from the bottom of the pre-combustion zone.

[0101] B5. The fluid catalytic decomposition and regeneration apparatus according to item B4, wherein the nozzle line of the inlet for the oxygen-deficient gas has an axial angle of 5 to 85°, preferably 15 to 75°.

[0102] B6. The fluid catalytic cracking regeneration apparatus according to item B1, wherein the catalyst circulation pipes are connected to the pre-combustion zone at positions where the distance from the bottom of the pre-combustion zone is independently 0 to 10% of the height of the pre-combustion zone.

[0103] B7. The fluid catalytic cracking and regeneration apparatus described in item B1, wherein the regenerator, the coke generation zone, and the pre-combustion zone are arranged coaxially.

[0104] B8. The fluid catalytic cracking regeneration apparatus described in item B7, wherein a catalyst discharge pipe is located at the top of the outlet of the pre-combustion zone, and the outlet of the pre-combustion zone, together with the catalyst discharge pipe, is located inside the regenerator.

[0105] B9. The fluid catalytic cracking regeneration apparatus according to item B1, wherein a gas distributor is located below the regenerator, and the gas distributor is configured to distribute rich oxygen gas introduced through one or more rich oxygen gas inlets located on the side wall of the regenerator.

[0106] B10. The fluid catalytic cracking and regeneration apparatus described in item B1, wherein the ratio of the inner diameter of the prelift zone to the inner diameter of the coke generation zone is 0.2:1 to 0.8:1, and the ratio of the height of the prelift zone to the height of the coke generation zone is 0.5:1 to 1.5:1.

[0107] B11. The fluid catalytic cracking and regeneration apparatus according to item B1, wherein the pre-combustion zone comprises a partial combustion section and an outlet section, and the partial combustion section has an inner diameter larger than the inner diameter of the outlet section.

[0108] B12. The fluid catalytic cracking and regeneration apparatus described in item B11, wherein the ratio of the inner diameter of the partial combustion section to the inner diameter of the outlet section is 10:1 to 2:1, and the ratio of the height of the partial combustion section to the height of the outlet section is 10:1 to 2:1.

[0109] B13. A catalytic cracking regeneration method, comprising the following steps, performed in a fluid catalytic cracking regeneration apparatus described in any one of items B1 to B12: A step of introducing the used catalyst into the prelift zone of the regenerator, bringing it into contact with and mixing it with the prelift medium, and moving it upward; A process of mixing a spraying medium with fuel oil, injecting the mixture into the fluid catalytic cracking regeneration apparatus through one or more fuel oil inlets, bringing the mixture into contact with the existing streams in the fluid catalytic cracking regeneration apparatus to carry out a coke formation reaction and obtain a coking catalyst; A step of introducing the coking catalyst into the pre-combustion zone, mixing the coking catalyst with the regenerated catalyst that has been circulated back to the pre-combustion zone through the catalyst circulation pipe and heating it, and carrying out a partial combustion reaction in the presence of oxygen-deficient gas introduced through one or more oxygen-deficient gas inlets; and A step of introducing a partial coking catalyst into the regenerator and carrying out a complete combustion reaction in the presence of rich oxygen gas introduced through the rich oxygen gas inlet to obtain a regenerated catalyst.

[0110] B14. The regeneration process according to item B13, wherein the prelift medium in the prelift zone is nitrogen, water vapor, or a mixture thereof; and the spray medium is nitrogen.

[0111] B15. The regeneration method described in item B13, wherein the mass ratio of the spraying medium to the fuel oil is 1:1 to 1:100.

[0112] B16. The regeneration method according to item B13, wherein the pre-combustion zone has a logarithmic mean linear velocity of 1.2 to 2.2 m / s; and the oxygen-depleted gas has an oxygen content of 1 to 20 volume%, more preferably 5 to 10 volume%, of the oxygen-depleted gas.

[0113] B17. The regeneration method described in item B13, wherein the temperature in the pre-combustion zone is 550 to 650°C.

[0114] B18. The regeneration method according to item B13, wherein the oxygen-rich gas in the regenerator has an oxygen content of 21% to 100% by volume, and more preferably, the oxygen-rich gas has an oxygen content of 21% to 85% by volume.

[0115] B19. The regeneration method described in item B13, wherein the temperature inside the regenerator is 600 to 800°C.

[0116] B20. A catalytic cracking system including a fluid catalytic cracking regeneration apparatus as described in any of items B1 to B12. [Examples]

[0117] The following examples further illustrate the present invention, but do not limit it. The catalyst used in the tests was a spent catalyst with a carbon content of 0.8% by weight, and the fuel oil was LCO derived from a commercially available catalytic cracking unit.

[0118] Example 1 The regeneration apparatus used in this embodiment was configured as shown in Figure 1. A rapid bed reactor from a medium-sized plant was used as the coke replenishment device, and a regenerator from a medium-sized plant was used as the regenerator. The coke replenishment device had an inner diameter of 0.3 m and a height of 2 m. The coke replenishment device had a fuel oil inlet located at a distance of 30% of the height of the coke replenishment device from the bottom of the coke replenishment device, and the outlet of the coke replenishment device communicated directly with the bottom opening of the regenerator, where a catalyst distributor was located.

[0119] A mixture of nitrogen with an oxygen content of 5% and air was introduced to the bottom of the coke replenishment device and sequentially mixed with the regenerating catalyst and spent catalyst, then moved upward to heat the spent catalyst so that the carbon on the spent catalyst would undergo a partial combustion reaction; nitrogen-prayed fuel oil was injected into the coke replenishment device and came into contact with the stream inside the coke replenishment device to carry out the coke formation reaction and a small amount of coke combustion reaction. The coking catalyst was sent into the regenerator and came into contact with the air entering the regenerator through the main air distributor to undergo a complete combustion reaction, thereby releasing heat. The main operating conditions of the regeneration process and the temperature profile changes of the regenerator are shown in Table 1.

[0120] A temperature measurement point was set up at the outlet of the coke replenishment device to measure the temperature at the outlet of the coke replenishment device; two temperature measurement points (at a 180-degree angle with respect to the axis) were set up at the same height, i.e., 40% of the axial height of the regenerator from the axial bottom of the regenerator, and close to the wall of the regenerator, to measure the temperature at the intermediate points at different positions at the same height; and a temperature measurement point was set up at the top of the regenerator to measure the temperature at the top of the regenerator.

[0121] As can be seen from Table 1, in Example 1, the temperature at the coke replenishment device outlet was 675°C, the temperatures at different locations in the middle of the regenerator were 687°C and 681°C, respectively, with a radial temperature difference of only 6°C, and the temperature at the top of the regenerator was 695°C, with a small temperature difference from the temperature in the middle section.

[0122] Comparative Example 1 In this comparative example, a conventional single-stage catalytic cracking regenerator was used. This regenerator had the same structure and dimensions as the regenerator of Example 1, except that only the fuel oil injection port was located in the catalyst dense phase zone at the bottom of the regenerator.

[0123] The spent catalyst was sent to the bottom of the regenerator and underwent a coke combustion reaction in contact with the air entering the regenerator from the main air distributor. Fuel oil was injected into the catalyst's dense phase layer and underwent a coke combustion reaction in contact with high-temperature air, thereby releasing heat. Table 1 shows the main operating conditions of the regeneration process and the changes in the regenerator's temperature profile.

[0124] Two temperature measurement points were set up at the same height, i.e., 40% of the axial height of the regenerator from the axial bottom of the regenerator, and close to the wall of the regenerator (at an angle of 180 degrees with respect to the axis), and the temperature of the intermediate part at different positions at the same height was measured; and a temperature measurement point was set up at the top of the regenerator to measure the temperature of the top of the regenerator.

[0125] As can be seen from Table 1, in Comparative Example 1, the temperatures at different locations in the middle section of the regenerator were 668°C and 725°C, respectively, with a radial temperature difference of 57°C, and the temperature at the top of the regenerator was 737°C, showing a large temperature difference from the temperature in the middle section.

[0126] [Table 1]

[0127] Example 2 The regeneration apparatus used in this embodiment was configured as shown in Figure 2, with a pre-lift zone having an inner diameter of 0.05 m and a length of 1 m, a coke generation zone having an inner diameter of 0.08 m and a length of 1 m, and a pre-combustion zone having an inner diameter of 0.3 m and a length of 2 m. The distance from the fuel oil inlet to the outlet end of the pre-combustion zone was 5% of the height of the pre-combustion zone, and the distance from the low-oxygen gas inlet to the bottom of the pre-combustion zone was 20% of the height of the pre-combustion zone.

[0128] Prelift nitrogen was sent to the bottom of the prelift zone, mixed with the spent catalyst, and moved upward. It came into contact with and mixed with fuel oil injected from the top of the prelift zone, and was then sent to the coke formation zone where the coke formation reaction took place. As it moved upward, it was continuously rectified, thereby ensuring a uniform distribution of coke. The coking catalyst was sent to the pre-combustion zone, where it came into contact with a low-oxygen gas (a mixture of nitrogen and air with an oxygen content of 5%) injected from the side walls of the pre-combustion zone to undergo a pre-combustion reaction, burning off a portion of the coke. The partially coked catalyst was sent into the regenerator, where it came into contact with the air entering the regenerator through the main air distributor to complete the reaction, thereby releasing heat.

[0129] Two temperature measurement points were set up at the same height, i.e., 40% of the axial height of the regenerator from the axial bottom of the regenerator, and close to the wall of the regenerator (at an angle of 180 degrees with respect to the axis). The temperature of the intermediate portion at different positions at the same height was measured; and a temperature measurement point was set up at the top of the regenerator to measure the temperature of the upper part of the regenerator. The main operating conditions of the regeneration process and the changes in the regenerator's temperature profile are shown in Table 2.

[0130] As can be seen from Table 2, in the regenerator of Example 2, the temperatures in the intermediate section at different positions at the same height in the radial direction were 683°C and 687°C, respectively, with a radial temperature difference of only 4°C, and the temperature at the top of the regenerator was 701°C, with a small temperature difference from the temperature in the intermediate section.

[0131] Comparative Example 2 In this comparative example, a conventional single-stage catalytic cracking regenerator was used. This regenerator had the same structure and dimensions as the regenerator in Example 2, except that only the fuel oil injection port was located in the catalyst dense phase zone at the bottom of the regenerator.

[0132] The spent catalyst was sent to the bottom of the regenerator and underwent a coke combustion reaction in contact with the air entering the regenerator from the main air distributor. Fuel oil was injected into the catalyst's dense phase layer and underwent a coke combustion reaction in contact with high-temperature air, thereby releasing heat.

[0133] Similarly, two temperature measurement points (at a 180-degree angle with respect to the axis) were set up at the same height, i.e., 40% of the axial height of the regenerator from the axial bottom of the regenerator, and close to the wall of the regenerator. The temperature of the intermediate portion at different positions at the same height was measured; a temperature measurement point was set up at the top of the regenerator to measure the temperature of the upper part of the regenerator. The main operating conditions of the regeneration process and the changes in the regenerator's temperature profile are shown in Table 2.

[0134] As can be seen from Table 2, in the regenerator of this comparative example, the temperatures of the intermediate sections at different positions but at the same height in the radial direction were 671°C and 730°C, respectively, with a radial temperature difference of 59°C. The temperature at the top of the regenerator was 740°C, showing a large temperature difference from the temperature of the intermediate section.

[0135] [Table 2]

[0136] From the results of the above examples and comparative examples, it is understood that catalyst regeneration carried out using the regeneration apparatus and regeneration method according to the present invention can raise the regeneration temperature to the temperature necessary to achieve heat balance, while keeping the coke combustion environment in the regeneration apparatus mild and stable, resulting in small radial and axial catalyst temperature gradients, which is beneficial for maintaining the physical and chemical properties of the catalyst.

[0137] Although the present invention has been described above in relation to preferred embodiments, these embodiments are merely illustrative and demonstrable. Based thereon, the present invention can be subjected to various substitutions and modifications, all of which fall within the scope of protection of the present invention.

Claims

1. A fluid catalytic cracking regeneration apparatus comprising a coke replenishment device, a regenerator, and an external catalyst circulation pipe, wherein the outlet of the coke replenishment device is in fluid communication with the inlet of the regenerator, the external catalyst circulation pipe connects the lower part of the regenerator to the coke replenishment device to return a portion of the catalyst in the regenerator to the coke replenishment device, the coke replenishment device is provided with an inlet for spent catalyst, an inlet for low oxygen gas, and an inlet for fuel oil, the inlet for rich oxygen gas is located at the bottom of the regenerator, and the fuel oil inlet is located downstream of the spent catalyst inlet along the direction of the flow of the stream.

2. The fluid catalytic cracking regeneration apparatus according to claim 1, characterized in that the external catalyst circulation pipe connects the lower part of the regenerator and the lower part of the coke supply device, and the oxygen-deficient gas inlet, the connection port between the external catalyst circulation pipe and the coke supply device, the spent catalyst inlet and the fuel oil inlet are sequentially arranged on the coke supply device along the direction of the flow of the stream.

3. The fluid catalytic cracking and regeneration apparatus according to claim 2, characterized in that the connection port of the external catalyst circulation pipe is located on the coke supply device at a distance of 3% to 20%, preferably 5% to 10%, from its bottom to the height of the coke supply device.

4. The fluid catalytic cracking and regeneration apparatus according to claim 1, characterized in that one or more fuel oil inlets, preferably one to three, are provided, and each is independently arranged on the coke supply device at a distance of 20% to 50%, preferably 25% to 40%, from the bottom of the coke supply device to the height of the coke supply device.

5. The fluid catalytic cracking and regeneration apparatus according to claim 1, having one or more of the following features: The oxygen-deficient gas inlet is located at the bottom of the coke supply device, and the first gas distributor is also located at the bottom of the coke supply device, thereby sending the oxygen-deficient gas injected through the oxygen-deficient gas inlet to the coke supply device through the first gas distributor; The catalyst distribution plate is located at the outlet of the coke supply device; The coke replenishment device is in the form of a hollow cylinder with a length-to-diameter ratio of 30:1 to 3:1, preferably 20:1 to 5:1; A second gas distributor is also located at the bottom of the regenerator, thereby sending the rich oxygen gas injected through the rich oxygen gas inlet to the regenerator through the second gas distributor; and The regenerator is in fluid communication with a gas-solid separator, and the regenerated exhaust gas generated by the regenerator is separated by the gas-solid separator and then introduced into an energy recovery system.

6. The coke replenishment device comprises, in order along the direction of the stream flow, a prelift zone, a coke generation zone, and a pre-combustion zone, wherein the outlet of the prelift zone is in fluid communication with the inlet of the coke generation zone, the outlet of the coke generation zone is in fluid communication with the inlet of the pre-combustion zone, and the outlet of the pre-combustion zone is in fluid communication with the inlet of the regenerator, and the external catalyst circulation pipe connects the lower part of the regenerator to the lower part of the pre-combustion zone; The fluid catalytic cracking and regeneration apparatus according to claim 1, wherein the inlet for used catalyst is located on the side wall of the prelift zone, one or more, preferably one to three, inlets for fuel oil are provided, each independently located on the side wall of the prelift zone and / or the side wall of the coke generation zone, and the inlet for oxygen-deficient gas is located on the side wall of the pre-combustion zone.

7. The one or more fuel oil inlets are independently positioned on the side wall of the prelift zone at a distance of 0 to 15%, preferably 0 to 10%, of the height of the prelift zone from their outlet ends, or alternatively The fluid catalytic cracking and regeneration apparatus according to claim 6, wherein the one or more fuel oil inlets are independently arranged on the side wall of the coke generation zone at a distance of 0 to 15%, preferably 0 to 10%, of the height of the coke generation zone from the bottom thereof.

8. The gas nozzle positioned at the oxygen-deficient gas inlet is located at a distance of 5% to 30%, preferably 10% to 20%, from the bottom of the pre-combustion zone to the side wall at the bottom of the pre-combustion zone; Preferably, the axial angle of the gas nozzle is 5 to 85°, preferably 15 to 75°, the fluid catalytic decomposition and regeneration apparatus according to claim 6.

9. The fluid catalytic decomposition and regeneration apparatus according to claim 6, wherein the connection port between the external catalyst circulation pipe and the side wall of the pre-combustion zone is located at a distance of 0 to 20%, preferably 0 to 10%, of the height of the pre-combustion zone from the bottom of the pre-combustion zone.

10. The fluid catalytic cracking and regeneration apparatus according to claim 6, having one or more of the following features: The regenerator is positioned coaxially with the prelift zone, the coke generation zone, and the pre-combustion zone of the coke supply device; A gas distributor is also located at the bottom of the regenerator, thereby sending the rich oxygen gas injected through the rich oxygen gas inlet to the regenerator through the gas distributor; The ratio of the inner diameter of the prelift zone to the inner diameter of the coke generation zone is 0.2:1 to 0.8:1, preferably 0.3:1 to 0.6:1, and the ratio of the height of the prelift zone to the height of the coke generation zone is 0.5:1 to 1.5:1, preferably 0.8:1 to 1.2:1; The pre-combustion zone includes, in order along the direction of the stream flow, a partial combustion section and an outlet section, wherein the inner diameter of the partial combustion section is larger than the inner diameter of the outlet section, preferably the ratio of the inner diameter of the partial combustion section to the inner diameter of the outlet section is 10:1 to 2:1, and the ratio of the height of the partial combustion section to the height of the outlet section is 10:1 to 2:1; and The catalyst discharge pipe is positioned at the top of the outlet of the pre-combustion zone, and the outlet of the pre-combustion zone is located inside the regenerator together with the catalyst discharge pipe.

11. A catalytic cracking system comprising a catalytic cracking reactor and a fluid catalytic cracking regeneration apparatus as described in claim 1.

12. A method for regenerating a catalyst using the fluid catalytic cracking regeneration apparatus described in claim 1, comprising the following steps: 1) A step of bringing a used catalyst into contact with fuel oil and oxygen-deficient gas in the coke supply device to carry out a coke formation reaction and a partial coke combustion reaction to obtain a partially coking catalyst; and 2) The process includes the step of bringing the partially coking catalyst into contact with oxygen-rich gas in the regenerator to carry out a complete combustion reaction and obtain a regenerated catalyst, Preferably, the low-oxygen gas has an oxygen content of 1 to 20% by volume, more preferably 5 to 10% by volume, and the rich-oxygen gas has an oxygen content of 21 to 100% by volume, more preferably 21 to 85% by volume.

13. A regeneration method according to claim 12, which is carried out in the fluid catalytic cracking regeneration apparatus according to claim 2, wherein step 1) further comprises the following steps: 1a) A step of heating the spent catalyst by mixing it with the regenerated catalyst derived from the regenerator through the external catalyst circulation pipe and bringing it into contact with the oxygen-deficient gas injected through the oxygen-deficient gas inlet, thereby carrying out a partial coke combustion reaction; and A regeneration method comprising the steps of: 1b) bringing the stream obtained in step 1a) into contact with a mixture of a spraying medium and fuel oil injected through the fuel oil inlet to carry out a coke formation reaction and a partial coke combustion reaction to obtain a partial coking catalyst.

14. The regeneration method according to claim 13, having one or more of the following features: The logarithmic mean linear velocity of the coke replenishment device is 1.2 to 2.2 m / s; The atomizing medium is nitrogen, and the mass ratio of the atomizing medium to the fuel oil is 1:1 to 1:100; The outlet temperature of the coke supply device is 550 to 650°C; and The temperature inside the regenerator is 620 to 800°C.

15. A regeneration method according to claim 13, which is carried out in the fluid catalytic cracking regeneration apparatus according to claim 6, wherein step 1) further comprises the following steps: 1a') A step of bringing the spent catalyst introduced through the prelift zone into contact with a mixture of a spray medium and fuel oil injected through the fuel oil inlet of the coke generation zone to carry out a coke generation reaction and obtain a coking catalyst; and A regeneration method comprising the steps of: 1b') mixing the stream obtained in step 1a') with the regeneration catalyst derived from the regenerator through the external catalyst circulation pipe of the pre-combustion zone, heating it, and bringing it into contact with the oxygen-poor gas injected through the oxygen-poor gas inlet to carry out a partial coke combustion reaction and obtain a partial coking catalyst.

16. The regeneration method according to claim 15, having one or more of the following features: The prelift medium in the aforementioned prelift zone is nitrogen, water vapor, or a mixture thereof; The atomizing medium is nitrogen, and the mass ratio of the atomizing medium to the fuel oil is 1:1 to 1:100; The logarithmic mean linear velocity in the aforementioned pre-combustion zone is 1.2 to 2.2 m / s; The outlet temperature of the pre-combustion zone is 550 to 650°C. The temperature inside the regenerator is 620 to 800°C.

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