Coke burning tank regeneration system and method for catalytic cracking process

Abstract

The application provides a catalytic cracking process coke drum regeneration system and method, the regeneration system comprises a catalytic cracking process coke drum regenerator (11) and an external heat supplement device (1); the external heat supplement device (1) comprises an electric energy supply heating device (2) and a shell (3); the electric energy supply heating device (2) is composed of a plurality of electric heating pipes (4); the external heat supplement device (1) further comprises a first catalyst conveying channel (5) and a second catalyst conveying channel (6) for being communicated with the catalytic cracking process coke drum regenerator; the first catalyst conveying channel (5) is arranged at the upper portion of the external heat supplement device (1), and the second catalyst conveying channel (6) is arranged at the lower portion of the external heat supplement device (1); the external heat supplement device (1) is communicated with the catalytic cracking process coke drum regenerator (10) through the first catalyst conveying channel (5) and the second catalyst conveying channel (6).

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and more specifically, to a coke oven regeneration system and method for a catalytic cracking process. Background Technology

[0002] Saturated hydrocarbon feedstocks with high alkane content are ideal for catalytic cracking to produce low-carbon olefins. The carbon-carbon bonds in alkanes are relatively weak, making them more prone to breakage after absorbing significant heat during cracking, thus forming low-carbon olefins. In contrast, aromatic carbons in the feedstock only undergo condensation reactions to form coke during catalytic cracking. This coke deposits on the catalyst surface and burns during regeneration, releasing heat and carbon dioxide. As future environmental regulations become increasingly stringent regarding carbon emissions, feedstocks with high aromatic carbon content will inevitably face restrictions.

[0003] However, limiting feedstocks with high aromatic carbon content means that the heat released during catalyst regeneration may be insufficient to maintain the thermal balance of the reaction-regeneration system, requiring external heat supplementation to meet the needs of reaction and regeneration. Traditional methods of relying on fossil fuels for heat supplementation increase carbon dioxide emissions. To address this challenge, electric heating devices have become an optimized option. Using electric heating devices to enhance heat transfer is one of the effective methods to increase the yield of low-carbon olefins and reduce carbon emissions.

[0004] Chinese patent application CN200510017540.1 discloses a heating or reheating method for a hydrocarbon processing unit reaction system. This method involves continuously or intermittently adding pulverized coal with a particle size of 10-140 μm to the catalyst regenerator via an automatic catalyst replenishment system and / or a catalyst additive addition system. This method results in more solid impurities in the regenerated flue gas, increasing the difficulty of subsequent treatment. Furthermore, the combustion of pulverized coal significantly increases carbon dioxide emissions.

[0005] Chinese patent application CN201510833567.1 discloses a supplementary heater, a catalytic cracking regeneration device, and a method for external heating. The supplementary heater is placed next to the catalyst regenerator and connected to the catalyst via a catalyst delivery pipeline to form a circulation. Diesel fuel or heavy oil with an auto-ignition point below 380°C is burned in the supplementary heater, causing uniform additional coke to form on the catalyst surface. This coke is then sent to the regenerator for complete combustion and heat release. However, the large amount of water vapor generated by the fuel combustion creates a high-temperature hydrothermal environment, accelerating the deactivation of the regenerator. Furthermore, the fuel combustion heating can easily cause localized excessively high temperatures on the catalyst, exceeding 1000°C, leading to collapse of the regenerator's pores and particle breakage, reducing catalyst stability and lifespan.

[0006] In addition, there are currently some internal and external heat supply devices, which are set up inside and outside the regenerator respectively. The internal heat supply device is set in the regenerator bed or main air duct. Since the heater lacks shell protection, it is prone to breakage under the action of main air or fluidizing medium. Moreover, the heat capacity of the regenerator bed or main air is small, and the heat exchange efficiency between it and the heater is low, making it difficult to ensure safety and unable to be used efficiently for a long period of time. The external heat supply device sets up a heater outside the regenerator and uses a riser structure to draw the catalyst from a certain bed of the regenerator. After being heated by the external heat supply device, it returns to the same bed. However, it does not consider the bed density of the catalyst in the external heat supply device to ensure sufficient heat capacity for efficient heat transfer. It also lacks the amount of catalyst circulation between the external heat supply device and the regenerator, and cannot guarantee the catalyst temperature of 700-800°C in the regenerator.

[0007] Bed regenerators are a commonly used dense-phase fluidized bed regeneration method in catalytic cracking units. Their low operating linear velocity and high backmixing degree bring them close to a fully mixed-flow operation. When the coke content on the catalyst is low, the heat released from coke combustion is insufficient to maintain the regeneration temperature, necessitating external heating of the regeneration unit. Current technologies primarily suffer from increased carbon dioxide emissions, and the high-temperature hydrothermal environment accelerates catalyst deactivation and breakage; alternatively, the electric heating equipment used does not consider the catalyst bed density and catalyst circulation rate within the unit, making it difficult to achieve effective heating for the regenerator. Therefore, there is a need to provide more environmentally friendly and efficient heating methods to optimize the catalytic cracking process. Summary of the Invention

[0008] One object of the present invention is to provide a coke oven regeneration system for a catalytic cracking process;

[0009] Another objective of this invention is to provide a method for reheating a coke oven regenerator in a catalytic cracking process.

[0010] To achieve the above objectives, in one aspect, the present invention provides a catalytic cracking process coke oven regeneration system, wherein the regeneration system includes a catalytic cracking process coke oven regenerator 11 and an external heating device 1; the external heating device 1 includes an electrically powered heating device 2 and a shell 3; the electrically powered heating device 2 is composed of multiple electric heating tubes 4; the external heating device 1 further includes a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for communication with the catalytic cracking process coke oven regenerator; the first catalyst delivery channel 5 is located at the upper part of the external heating device 1, and the second catalyst delivery channel 6 is located at the lower part of the external heating device 1; the external heating device 1 is connected to the catalytic cracking process coke oven regenerator 11 through the first catalyst delivery channel 5 and the second catalyst delivery channel 6.

[0011] According to some specific embodiments of the present invention, the number of electric heating tubes 4 is 2-50.

[0012] According to some specific embodiments of the present invention, the number of electric heating tubes 4 is 5-40.

[0013] According to some specific embodiments of the present invention, the number of electric heating tubes 4 is 10-30.

[0014] According to some specific embodiments of the present invention, the electric heating tubes 4 are arranged in a cluster.

[0015] According to some specific embodiments of the present invention, the electric heating tube 4 is fixedly installed on the flange cover 10 of the external heating device 1.

[0016] According to some specific embodiments of the present invention, the electric heating tubes 4 are connected in parallel.

[0017] The electric heating element 4 is controlled by an external control circuit to achieve individual, partial, or complete power-on heating of the electric heating element.

[0018] Each electric heating element 4 has the same heating power, and the total heating power is equal to the total power of the electric heating device 2.

[0019] According to some specific embodiments of the present invention, the electric heating tube 4 includes a heating tube shell 41, an electric heating element 42 disposed inside the heating tube shell, and fins 43 disposed on the outer surface of the heating tube shell 41.

[0020] According to some specific embodiments of the present invention, the electric heating element 42 is required to withstand 1400°C.

[0021] According to some specific embodiments of the present invention, the heating tube housing 41 is a ceramic heating tube housing.

[0022] According to some specific embodiments of the present invention, the ceramic heating tube shell can withstand high temperatures exceeding 1200°C for extended periods.

[0023] This invention utilizes ceramic materials to make the outer shell of the heating tube. The high hardness of ceramic materials solves the problem of the need for the outer surface of the electric heating tube 4 to withstand high wear resistance for a long time under high temperature and catalyst fluidization conditions.

[0024] According to some specific embodiments of the present invention, the fins 43 are arranged in a spiral configuration around the heating tube housing 41 from top to bottom.

[0025] According to some specific embodiments of the present invention, the fin 43 is arranged with a swirl angle of 30°-60°.

[0026] According to some specific embodiments of the present invention, the width of the fin 43 is 0.1-1.0 times the diameter of the heating tube shell 41.

[0027] The fins of this invention increase the disturbance and heat transfer area of ​​the catalyst particles in the external heating device, thereby improving the heating efficiency of the electrically powered heating device.

[0028] According to some specific embodiments of the present invention, the electric heating tube 4 further includes a temperature sensor and an over-temperature protection component 44 disposed inside the heating tube housing 41.

[0029] According to some specific embodiments of the present invention, a horizontal deflection structure 7 is provided inside the first catalyst delivery channel 5 at the connection with the external heating device 1.

[0030] According to some specific embodiments of the present invention, the angle between the horizontal steering structure 7 and the conveying channel 5 is 30 degrees to 60 degrees.

[0031] According to some specific embodiments of the present invention, the horizontal steering structure 7 has a height h ( Figure 1 h) is smaller than the pipe diameter ( Figure 1 1 / 4 of R in the equation.

[0032] According to some specific embodiments of the present invention, a valve 8 is provided on the second catalyst delivery channel 6.

[0033] According to some specific embodiments of the present invention, the valve 8 is a slide valve.

[0034] According to some specific embodiments of the present invention, the external heating device 1 is provided with a catalyst fluidization distributor 9 at the bottom of the inner cavity.

[0035] According to some specific embodiments of the present invention, one or two external heating devices 1 are provided.

[0036] According to some specific embodiments of the present invention, there are two external heating devices 1, which are symmetrically arranged on both sides of the coke burner regenerator 11 in the catalytic cracking process.

[0037] According to some specific embodiments of the present invention, two external heating devices 1 are provided and are symmetrically distributed on both sides of the coke burner regenerator 5 in the catalytic cracking process.

[0038] On the other hand, the present invention also provides a method for supplementing heat to the coke burner regenerator in a catalytic cracking process, wherein the method includes supplementing heat to the coke burner regenerator in a catalytic cracking process using any of the external heat supplementation devices described above in the present invention.

[0039] According to some specific embodiments of the present invention, the linear velocity of the fluidizing gas in the external heating device 1 is 0.05-1 m / s.

[0040] According to some specific embodiments of the present invention, the linear velocity of the fluidizing gas in the external heating device 1 is 0.1-0.4 m / s.

[0041] According to some specific embodiments of the present invention, the linear velocity of the fluidizing gas in the external heating device 1 is 0.2-0.3 m / s.

[0042] According to some specific embodiments of the present invention, the operating temperature inside the external heating device 1 is 650 to 950°C.

[0043] According to some specific embodiments of the present invention, the operating temperature inside the external heating device 1 is 700-850°C.

[0044] According to some specific embodiments of the present invention, the operating temperature inside the external heating device 1 is 800-820°C.

[0045] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 200-700 kg / m³. 3 .

[0046] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 300-650 kg / m³. 3 .

[0047] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 600-650 kg / m³. 3 .

[0048] According to some specific embodiments of the present invention, the catalyst circulation rate between the external heating device 1 and the catalytic cracking process coke burner regenerator is 0.05 to 1.0 times the catalyst circulation rate of the catalytic cracking reaction system.

[0049] According to some specific embodiments of the present invention, the catalyst circulation rate between the external heating device 1 and the catalytic cracking process coke burner regenerator is 0.1 to 0.5 times the catalyst circulation rate of the catalytic cracking reaction system.

[0050] According to some specific embodiments of the present invention, the catalyst circulation rate between the external heating device 1 and the catalytic cracking process coke burner regenerator is 0.25 to 0.35 times the catalyst circulation rate of the catalytic cracking regeneration system.

[0051] The catalytic cracking regeneration system of the present invention includes a catalytic cracking bed regeneration system and a catalytic cracking reaction system (e.g., a riser reactor or a turbulent fluidized bed reactor).

[0052] Both the catalytic cracking bed regeneration system and the catalytic cracking reaction system can be conventional catalytic cracking bed regeneration systems and catalytic cracking reaction systems in the art.

[0053] According to some specific embodiments of the present invention, the heat compensation coefficient of the external heat compensation device 1 is 0.05 to 5.0.

[0054] According to some specific embodiments of the present invention, the heat compensation coefficient of the external heat compensation device 1 is 0.5 to 2.

[0055] According to some specific embodiments of the present invention, the operating temperature inside the external heating device 1 is 800–820°C, the linear velocity of the fluidizing gas inside the external heating device 1 is 0.2–0.3 m / s, and the catalyst bed density inside the external heating device 1 is 600–650 kg / m³. 3 The amount of catalyst circulating between the external heating device 1 and the catalytic cracking process coke burner regenerator is 0.25 to 0.35 times the amount of catalyst circulating in the catalytic cracking reaction system.

[0056] According to some specific embodiments of the present invention, the operating temperature inside the external heating device 1 is 800°C, the linear velocity of the fluidizing gas inside the external heating device 1 is 0.24 m / s, and the catalyst bed density inside the external heating device 1 is 650 kg / m³. 3 The amount of catalyst circulating between the external heating device 1 and the catalytic cracking process coke burner regenerator is 0.30 times the amount of catalyst circulating in the catalytic cracking reaction system.

[0057] The total heat replenishment of the external heating device 1 of the present invention is equal to the heat replenishment coefficient * (heat required by the catalytic cracking reactor - heat of coke combustion); the heat of coke combustion is equal to the enthalpy of coke combustion × the amount of raw material processed × the coke yield; the total power of the electric heating device 2 of the external heating device 1 is equal to the total heat replenishment of the external heating device per unit time.

[0058] In summary, this invention provides an external heating device, system, and method for a coke oven regenerator in a catalytic cracking process. The device of this invention has the following advantages:

[0059] An electrically powered external heating device is used to externally heat the regenerated catalyst. No hydrothermal environment is generated inside the external heating device, which can avoid structural deactivation of the catalyst even under overheating conditions, thereby reducing catalyst consumption and achieving heat balance between the catalytic cracking reaction and the regeneration system.

[0060] By using electric power to reheat the regenerated catalyst instead of the existing method of adding fuel oil or pulverized coal for reheating, there is no new carbon dioxide emission;

[0061] This invention, by flexibly adjusting the catalyst bed density and catalyst circulation rate of the external heating device, can efficiently transfer the heat energy converted from electrical energy to the regenerator and catalytic cracking reactor, thereby achieving high-temperature regeneration of the spent catalyst and improving the efficiency of the heating to achieve energy saving.

[0062] This invention uses an external heating device equipped with an electric heating tube bundle, which can quickly and accurately control the temperature of the catalyst in the regenerator by adjusting the current or voltage, and flexibly adjust the process conditions of the reactor.

[0063] This invention places the heat replenishment device outside the regenerator, which can prevent the heat replenishment device from aging at high temperatures, avoid the impact of heat replenishment device failure on the regenerator, ensure the safe use of the equipment, and significantly extend its service life. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the external heating device and the catalytic cracking process coke burner regeneration system of Embodiment 1 of the present invention.

[0065] Figure 2 This is an enlarged schematic diagram of the electric heating tube in Embodiment 1 of the present invention. Detailed Implementation

[0066] The following detailed embodiments illustrate the implementation process and beneficial effects of the present invention, aiming to help readers better understand the essence and characteristics of the present invention, and are not intended to limit the scope of implementation of this case.

[0067] Example 1

[0068] Industrial production equipment is used, according to Figure 1 The diagram shows an external heating device for the coke oven regenerator in a catalytic cracking process, which utilizes electrical power for heat replenishment. The external heating device includes: an external heating device 1 with an internally installed electrically powered heating device 2 and a catalyst fluidization distributor 9; a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for conveying catalyst into and out of the external heating device 1; a horizontal deflection structure 7 at the outlet end of the first catalyst delivery channel 5 and a slide valve 8 on the second catalyst delivery channel 6; and a catalytic cracking coke oven regenerator 11.

[0069] The catalyst exiting the coke oven regenerator 11 of the catalytic cracking process enters the external heating device 1 through the first catalyst conveying channel 5 and the horizontal deflection structure 7 at the outlet of the first catalyst conveying channel 5. Within the external heating device, under the action of the catalyst fluidizer 9, a uniformly distributed catalyst particle bed is formed, which fully exchanges heat with the electrically powered heating device 2. The linear velocity of the fluidizing gas within the external heating device 1 is 0.25 m / s; the operating temperature within the external heating device 1 is 750℃; and the catalyst bed density is adjusted to 400 kg / m³ by regulating the linear velocity of the fluidizing gas within the external heating device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the catalyst circulation rate between the external heating device 1 and the catalytic cracking process coke burner regenerator 11 is 0.45 times the catalyst circulation rate of the catalytic cracking reaction regeneration system.

[0070] Taking a catalytic cracking unit for producing low-carbon olefins with a processing capacity of 200 tons / h of light hydrocarbons as an example, the coke yield is 3.20% (mass fraction), and the amount of coke burned in the regenerator per hour is 6.40 tons. Therefore, the heat released by coke combustion is 2.30 * 10⁻⁶ tons / hour. 8 The catalytic cracking reactor requires 6.41 kJ / h of heat. 8 To maintain the heat balance of the reaction-regeneration system in the catalytic cracking unit, the preferred heat compensation coefficient is 1.2. The total heat compensation of external heat compensation device 1 = 1.2 * (heat required by the catalytic cracking reactor - heat of coke combustion) = 4.932 * 10^-10 kJ / h. 8 If the power is kJ / h, then the total power of the external heating device 1 is 137.01MW.

[0071] Based on the total power of the external heating device 1, 30 electric heating tubes are installed, each with a power of 4.567MW. The electric heating tubes are connected in parallel and controlled individually through an external control circuit to achieve individual, partial, or complete energization and heating of each tube. Figure 2 As shown, each electric heating tube 4 contains an electric heating element 42, a temperature sensor, and an over-temperature protection element 44. The electric heating element is required to withstand 1400℃. To address the wear problem on the outer surface of the electric heating tube 4 under high temperature and catalyst fluidization conditions, the outer surface of the electric heating tube 4 is a ceramic heating tube shell 41. The ceramic heating tube shell 41 outside the electric heating tube 4 can be equipped with fins 43 (with a spiral angle of 32° and a width of 0.15 times the diameter of the heating tube shell 41) to increase the disturbance of catalyst particles and the heat transfer area in the heater, thereby improving the heating efficiency of the electrically powered heating device.

[0072] The operating conditions within the external heating device 1 of Example 1 are shown in Table 1:

[0073] Table 1 Main Operating Conditions of External Heating Device

[0074] Heater pressure, MPa (A) 0.30 0.33 Heater operating temperature, °C 750 680 Gas linear velocity, m / s 0.25 0.25 Oxygen content in the flue gas at the outlet, v% No smoke produced 0.5 Fuel to catalyst ratio fuel-free use 1:6-500 Will it increase carbon dioxide emissions? none have

[0075] As can be seen from the data in Table 1, using Example 1 (the comparative data in Table 1 comes from the invention patent CN201510833567.1), compared with other current heat exchanger methods (heat exchanger, catalytic cracking regeneration device and external heat exchanger method. Invention patent CN201510833567.1), using an electrically powered heat exchanger to externally heat the regenerated catalyst allows the heat exchanger to operate at a higher temperature, and there is no hydrothermal environment generated inside the heat exchanger, no flue gas is generated, and no new carbon dioxide emissions are generated.

[0076] Example 2

[0077] Using an experimental pilot-scale apparatus, according to Figure 1 The diagram shows an external heating device for the coke oven regenerator in a catalytic cracking process, which utilizes electrical power for heat replenishment. The external heating device includes: an external heating device 1 with an internally installed electrically powered heating device 2 and a catalyst fluidization distributor 9; a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for conveying catalyst into and out of the external heating device 1; a horizontal deflection structure 7 at the outlet end of the first catalyst delivery channel 5 and a slide valve 8 on the second catalyst delivery channel 6; and a catalytic cracking coke oven regenerator 11.

[0078] The catalyst exiting the coke oven regenerator 11 of the catalytic cracking process enters the external heating device 1 through the first catalyst conveying channel 5 and the horizontal deflection structure 7 at the outlet end of the first catalyst conveying channel. Under the action of the catalyst fluidizer 9 within the external heating device 1, a uniformly distributed catalyst particle bed is formed, which fully exchanges heat with the electrically powered heating device 2. The linear velocity of the fluidizing gas within the external heating device 1 is 0.35 m / s; the operating temperature within the external heating device 1 is 800℃; and the catalyst bed density is adjusted to 550 kg / m³ by regulating the linear velocity of the fluidizing gas within the external heating device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the catalyst circulation rate between the external heating device 1 and the catalytic cracking process coke burner regenerator 11 is 0.1 times the catalyst circulation rate of the catalytic cracking reaction regeneration system.

[0079] Taking a pilot-scale catalytic cracking plant for producing low-carbon olefins with a naphtha processing capacity of 15 kg / h as an example, the coke yield is 3.68% (mass fraction), and the amount of coke burned in the regenerator per hour is 0.5595 kg. Therefore, the heat released by coke combustion is 2.01 * 10⁻⁶. 4 The catalytic cracking reactor requires 4.14 kJ / h of heat. 4 To maintain the heat balance of the reaction-regeneration system in the catalytic cracking unit, the preferred heat compensation coefficient is 2.0. The total heat compensation of external heat compensation device 1 = 2.0 * (heat required by the catalytic cracking reactor - heat from coke combustion) = 4.26 * 10^-10 kJ / h.4 If the power is kJ / h, then the total power of the external heating device 1 is 11.83MW.

[0080] Ten electric heating tubes are set according to the total power of the external heating device 1, with each electric heating tube having a power of 1.2MW. The electric heating tubes are connected in parallel and controlled individually through an external control circuit to achieve heating of each, partially, or all of them. Each electric heating tube 4 contains an electric heating element 42, a temperature sensor, and an over-temperature protection element 44. The electric heating element is required to withstand 1400℃. To solve the problem of wear on the outer surface of the electric heating tube 4 under high temperature and catalyst fluidization conditions, the outer surface of the electric heating tube 4 is a ceramic heating tube shell 41. The ceramic shell 41 of the electric heating tube 4 can be equipped with fins 43 (with a spiral angle of 40° and a width of 0.20 times the diameter of the heating tube shell 41) to increase the disturbance of catalyst particles and the heat transfer area in the heater, thereby improving the heating efficiency of the electric heating device.

[0081] Given that catalytic cracking is a deep catalytic cracking reaction, to compare the effects of Example 2 on catalyst and product yield, other current heat replenishment methods were selected (a catalyst regeneration method and equipment for supplementing heat in a catalytic cracking unit, invention patent CN201110272641.9). The data for the comparative examples in Tables 2-4 are from invention patent CN201110272641.9. Example 2 was tested in a pilot-scale unit for catalytic cracking to produce low-carbon olefins with a naphtha processing capacity of 15 kg / h, also using naphtha as the catalytic cracking feedstock. The feedstock properties are shown in Table 2. Compared with the comparative examples, the properties of the feedstock in Example 2 were slightly worse, with a slightly lower alkane content and a higher aromatic content.

[0082] Table 2 Properties of Naphtha Raw Materials

[0083] <![CDATA[Density (20°C), g / cm 3 > 0.7387 0.7358 Vapor pressure, kPa 49.5 50.0 Family composition, w% Alkanes 49.92 51.01 Cycloalkanes 38.23 38.24 Olefins 0.12 0.12 Aromatics 11.73 10.52 Distillation range, °C IBP 47 46 10％ 89 87 30％ 110 107 50％ 121 120 70％ 135 133 90％ 152 149 95％ 157 155

[0084] Table 3 shows a comparison of catalyst properties. Since no hydrothermal environment is generated inside the heater, structural deactivation of the catalyst can be avoided even under overheating conditions. Therefore, the catalyst pore volume and specific surface area of ​​Example 2 are significantly increased compared with the comparative example, and the proportion of catalyst particles smaller than 40 μm is significantly reduced, which is beneficial to improving the catalytic cracking reaction effect.

[0085] Table 3 Catalyst Properties

[0086]

[0087]

[0088] Table 4 compares the operating conditions and product distribution. By using electric power to reheat the regenerated catalyst instead of adding fuel oil for reheating in the comparative example, no new carbon dioxide emissions are generated. The temperature of the catalyst in the regenerator can be quickly and accurately controlled by adjusting the current or voltage, which significantly increases the regeneration temperature. The catalyst properties and reactor process conditions can be flexibly adjusted, which can significantly improve the yield of the target product ethylene + propylene.

[0089] Table 4 Operating Conditions and Product Distribution

[0090]

[0091]

[0092] Example 3

[0093] To verify that the present invention can better ensure sufficient heat capacity and achieve efficient heat transfer by controlling the circulation amount of catalyst between the external heating device and the catalytic cracking bed regenerator, thereby adjusting the bed density in the external heating device, a single-factor experiment was conducted to compare Example 3 with Example 1 of the present invention.

[0094] Industrial production equipment is used, according to Figure 1 The external heating device for the catalytic cracking bed regenerator shown uses electric power for heat replenishment, employing the method of Example 1. The linear velocity of the fluidizing gas within the external heating device 1 is 0.25 m / s; the operating temperature within the external heating device 1 is 750 °C; and the catalyst bed density is adjusted to 400 kg / m³ by regulating the linear velocity of the fluidizing gas within the external heating device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the catalyst circulation rate between the external heating device 1 and the catalytic cracking coke burner regenerator 11 is made 0.45 times the catalyst circulation rate of the catalytic cracking reverse regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a light hydrocarbon processing capacity of 200 tons / h as an example, the coke yield is 3.20% (mass fraction), and the amount of coke burned in the regenerator per hour is 6.40 tons. Therefore, the heat released by coke combustion is 2.30 * 10⁻⁶ tons / hour. 8 The catalytic cracking reactor requires 6.41 kJ / h of heat. 8 To maintain the heat balance of the reaction-regeneration system in the catalytic cracking unit, the heat compensation coefficient is 1.2. Therefore, the total heat compensation of external heat compensation device 1 = 1.2 * (heat required by the catalytic cracking reactor - heat of coke combustion) = 4.932 * 10^-10 kJ / h. 8 If the power is kJ / h, then the total power of the external heating device 1 is 137.01MW.

[0095] Industrial production equipment is used, according to Figure 1The external heating device for the catalytic cracking bed regenerator, which utilizes electric power, supplements heat using the following method: the linear velocity of the fluidizing gas in the external heating device 1 is 0.25 m / s; the operating temperature in the external heating device 1 is 750℃; and the catalyst bed density is adjusted to 600 kg / m³ by regulating the linear velocity of the fluidizing gas in the external heating device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the catalyst circulation rate between the external heating device 1 and the catalytic cracking bed regenerator 11 is made 0.35 times the catalyst circulation rate of the catalytic cracking regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a light hydrocarbon processing capacity of 200 tons / h as an example, the coke yield is 3.20% (mass fraction), and the amount of coke burned in the regenerator per hour is 6.40 tons. Therefore, the heat released by coke combustion is 2.30 * 10⁻⁶ tons / hour. 8 The catalytic cracking reactor requires 6.41 kJ / h of heat. 8 To maintain the heat balance of the reaction-regeneration system in the catalytic cracking unit, the heat compensation coefficient is 1.1. Therefore, the total heat compensation of external heat compensation device 1 = 1.1 * (heat required by the catalytic cracking reactor - heat of coke combustion) = 4.525 * 10^-10 kJ / h. 8 If the power is kJ / h, then the total power of the external heating device 1 is 125.69MW.

[0096] By adjusting the bed density inside the external heating device, the heating power of the heater can be significantly reduced, and sufficient catalyst heat capacity can be guaranteed to achieve efficient heat transfer.

[0097] Comparative Example

[0098] Industrial production equipment is used, according to Figure 1 The catalytic cracking bed regenerator shown uses an external heating device powered by electricity for heat replenishment. The linear velocity of the fluidizing gas in the external heating device 1 is 0.23 m / s; the operating temperature in the external heating device 1 is 750℃; and the catalyst bed density is adjusted to 150 kg / m³ by adjusting the linear velocity of the fluidizing gas in the external heating device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the catalyst circulation rate between the external heating device 1 and the catalytic cracking coke burner regenerator 11 is made 0.1 times the catalyst circulation rate of the catalytic cracking reverse regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a light hydrocarbon processing capacity of 200 tons / h as an example, the coke yield is 3.20% (mass fraction), and the amount of coke burned in the regenerator per hour is 6.40 tons. Therefore, the heat released by coke combustion is 2.30 * 10⁻⁶ tons / hour. 8 The catalytic cracking reactor requires 6.41 kJ / h of heat. 8To maintain the heat balance of the reaction-regeneration system in the catalytic cracking unit, the heat compensation coefficient is 1.15. Therefore, the total heat compensation of external heat compensation device 1 = 1.15 * (heat required by the catalytic cracking reactor - heat of coke combustion) = 4.726 * 10^-10 kJ / h. 8 If the power is kJ / h, then the total power of the external heating device 1 is 130.4MW.

[0099] Table 5 shows that the optimization of catalyst bed density and circulation rate significantly improved catalyst performance and the yield of low-carbon olefins, as demonstrated by the data from Examples 1, 2, and Comparative Example 3 of the industrial production unit. Specifically, in Example 3, the ethylene + propylene yield reached 57.14%, significantly higher than in the other examples. The catalyst pore volume and specific surface area in the examples were significantly better than in the comparative example, indicating that the optimized parameter settings significantly enhanced catalyst regeneration and stability. Overall, the efficient heat support provided by the external heating device, especially at higher catalyst bed densities and circulation rates, significantly improved reaction efficiency and achieved energy savings.

[0100] Table 5 Main operating conditions and product properties of external heating device

[0101]

[0102]

[0103] In this invention, the catalysts in each embodiment and comparative example are from the same batch with the same parameters, and other parameters of the catalysts in industrial production are also the same. The only difference between each embodiment and comparative example is the different parameter settings of the regenerator external heating device in Table 5, so as to exclude the influence of other factors other than these parameters.

Claims

1. A method for reheating a regenerator in a coke burner during a catalytic cracking process, wherein, The method includes supplementing the heat of the coke burner regenerator (11) in the catalytic cracking process using an external heating device (1); the method includes the following parameters: The linear velocity of the fluidizing gas in the external heating device (1) is 0.05-1 m / s; The operating temperature inside the external heating device (1) is 650~950℃; The catalyst bed density in the external heating device (1) is 200~700 kg / m³. 3 ; The amount of catalyst circulating between the external heating device (1) and the regenerator of the coke burner in the catalytic cracking process is 0.05 to 1.0 times the amount of catalyst circulating in the catalytic cracking regeneration system; The external heating device (1) includes an electrically powered heating device (2) and a shell (3); the electrically powered heating device (2) is composed of multiple electric heating tubes (4); the external heating device (1) also includes a first catalyst delivery channel (5) and a second catalyst delivery channel (6) for communication with the coke oven regenerator of the catalytic cracking process; the first catalyst delivery channel (5) is located at the upper part of the external heating device (1), and the second catalyst delivery channel (6) is located at the lower part of the external heating device (1); the external heating device (1) is connected to the coke oven regenerator (11) of the catalytic cracking process through the first catalyst delivery channel (5) and the second catalyst delivery channel (6).

2. The method according to claim 1, wherein, The linear velocity of the fluidizing gas in the external heating device (1) is 0.1-0.4 m / s.

3. The method according to claim 1, wherein, The operating temperature inside the external heating device (1) is 700~850℃.

4. The method according to claim 1, wherein, The catalyst bed density in the external heating device (1) is 300~650 kg / m³. 3 .

5. The method according to claim 1, wherein, The amount of catalyst circulating between the external heating device (1) and the catalytic cracking process coke burner regenerator is 0.1 to 0.5 times the amount of catalyst circulating in the catalytic cracking reaction system.

6. The method according to any one of claims 1 to 5, wherein, The number of electric heating tubes (4) is 2-30.

7. The method according to any one of claims 1 to 5, wherein, The first catalyst delivery channel (5) has a horizontal steering structure (7) at the connection with the external heating device (1).

8. The method according to any one of claims 1 to 5, wherein, A valve (8) is installed on the second catalyst delivery channel (6).

9. The method according to any one of claims 1 to 5, wherein, The electric heating tube (4) includes a heating tube shell (41), an electric heating element (42) disposed inside the heating tube shell, and fins (43) disposed on the outer surface of the heating tube shell (41).

10. The method according to claim 9, wherein, The heating tube housing (41) is a ceramic heating tube housing.

11. The method according to claim 9, wherein, The fins (43) are arranged in a spiral pattern around the heating tube shell (41) from top to bottom.

12. The method according to claim 9, wherein, The electric heating tube (4) also includes a temperature sensor and an over-temperature protection component (44) disposed inside the heating tube housing (41).

13. The method according to any one of claims 1 to 5, wherein, The external heating device (1) has a catalyst fluidization distributor (9) installed at the bottom of the inner cavity.

14. The method according to any one of claims 1 to 5, wherein, There are two external heating devices (1), which are symmetrically arranged on both sides of the coke burner regenerator (11) in the catalytic cracking process.

Images