External heat compensation device, system and method for catalytic cracking bed regenerator

Abstract

The invention provides an external heat compensation device, system and method for a catalytic cracking bed regenerator. The external heat compensation 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 electric energy supply external heat compensation device is used for performing external heat compensation on the regenerated catalyst, no hydrothermal environment is generated in the external heat compensation device, and the catalyst can be prevented from being structurally inactivated even under an overheat condition, so that the catalyst consumption is reduced, and the heat balance of a catalytic cracking reaction-regeneration system is realized.

Description

Technical Field

[0001] The present invention relates to the field of chemical industry, and in particular to an external heat supplement device, system and method for a catalytic cracking bed regenerator. Background Art

[0002] Saturated hydrocarbon-rich feedstocks have a high content of chain alkanes and are high-quality feedstocks for catalytic cracking to produce light olefins. Due to the large carbon-carbon bond energy of short-chain and cycloalkane saturated hydrocarbons, a large amount of heat energy is required to fully break the carbon-carbon bond in the cracking reaction to produce light olefins; in addition, hydrocarbons with aromatic carbon structures in the feedstock cannot generate light olefins during the catalytic cracking process. Under high temperature conditions, only condensation reactions occur to generate coke, and the coke is deposited on the catalyst and burns to release heat and carbon dioxide during regeneration. In the future, environmental regulations will become increasingly stringent on carbon emissions from catalytic cracking units, and the aromatic carbon content in the feedstock will inevitably be restricted. Therefore, since the catalytic cracking of saturated hydrocarbons produces less coke, aromatic hydrocarbons that are easy to generate coke will be limited in the feedstock, and the heat generated by the regeneration of the coke-deposited catalyst cannot maintain the thermal balance of the catalytic cracking reaction-regeneration system, and external heat supplementation is required to achieve the heat required for reaction and regeneration. The conventional combustion of fossil fuels to supplement heat to the catalytic cracking reaction-regeneration system will cause excessive carbon dioxide emissions, and the electric heating device that enhances heat transfer is one of the most effective ways to increase the production of light olefins and reduce carbon emissions in saturated hydrocarbon catalytic cracking units.

[0003] Invention patent application CN200510017540.1 discloses a method for heating or supplementing heat of a hydrocarbon processing device reaction system, which is to continuously or intermittently add coal powder with a particle size of 10-140μm to a catalyst regenerator through the catalyst automatic replenishment system and / or catalyst promoter addition system of the hydrocarbon processing device. The regeneration flue gas generated by the combustion of coal powder using this method will contain more solid impurity particles, which increases the difficulty of treating the regeneration flue gas, and the combustion of coal powder will cause an increase in carbon dioxide emissions.

[0004] The invention patent application CN201510833567.1 discloses a reheater, a catalytic cracking regeneration device and a method for external heat supplementation, by arranging the reheater next to the catalyst regenerator, and connecting it to the catalyst regenerator through a catalyst delivery pipeline to form a loop. Diesel or heavy oil with an auto-ignition point below 380°C is burned in the reheater to form uniform additional coke on the catalyst surface, and then sent to the regenerator through a pipeline and a control slide valve for complete combustion and heat release, thereby achieving a uniform temperature rise on the surface of the catalyst particles and achieving the purpose of protecting the physical properties and chemical activity of the catalyst. However, the combustion of oil in the reheater will inevitably produce a large amount of water vapor. The harsh high-temperature hydrothermal environment will accelerate the deactivation of the regeneration agent, and the oil combustion heat supplement will easily cause the local temperature of the catalyst to be too high, reaching more than 1000°C, causing the regeneration agent pores to collapse and the particles to break, increasing the consumption of the catalyst.

[0005] In addition, there are currently some internal and external heat supplement equipment, which are heat supplement equipment installed inside and outside the regenerator respectively. The internal heat supplement equipment is installed in the regenerator bed or the main air duct. Since the heater lacks shell protection, it is easy to break under the action of the main air or fluidized medium, and the regenerator bed or main air has a small heat capacity, and the heat exchange efficiency between the heater and the heater is low, which makes it difficult to ensure safety and cannot be used efficiently for a long period of time; the external heat supplement equipment is installed outside the regenerator, and a lifting riser structure is used to draw out the catalyst from a certain bed of the regenerator. After being heated by the external heat supplement equipment, it returns to the same bed. However, the bed density of the catalyst in the external heat supplement equipment is not considered to ensure sufficient heat capacity to achieve efficient heat transfer, and there is also a lack of circulation of the catalyst between the external heat supplement equipment and the regenerator, and it is impossible to ensure that the catalyst temperature of 700-800°C in the regenerator is achieved.

[0006] For catalytic cracking units, bed regenerators are a commonly used dense phase fluidized bed regeneration method with low operating linear velocity, high degree of back mixing of bed catalyst, and a tendency towards full mixed flow operation. When the catalytic cracking reaction produces little coke and the coke content on the catalyst is low, the heat released by the coke combustion is difficult to maintain the normal coking temperature, and heat needs to be added to the regeneration unit. However, the above technologies all have limitations in application. Mainly, in the current context, these technologies increase the carbon dioxide emissions of the unit. In addition, the high temperature hydrothermal environment formed by the combustion of the fuel causes deactivation or breakage of the regenerated catalyst and other adverse effects. Summary of the invention

[0007] One object of the present invention is to provide an external heat supplement device for a catalytic cracking bed regenerator;

[0008] Another object of the present invention is to provide a catalytic cracking bed regeneration system;

[0009] Another object of the present invention is to provide a method for supplementing heat in a catalytic cracking bed regenerator.

[0010] To achieve the above objectives, on the one hand, the present invention provides an external heat supply device for a catalytic cracking bed regenerator, wherein the external heat supply device 1 includes an electrically powered heating device 2 and a shell 3; the electrically powered heating device 2 is composed of a plurality of electric heating tubes 4.

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

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

[0013] According to some specific embodiments of the present invention, the number of the 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 clusters.

[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 tubes 4 are controlled separately through external control circuits to realize heating of the electric heating tubes one by one, partially or completely.

[0018] The heating power of each electric heating tube 4 is the same, and the total heating power is equal to the total power of the electrically powered 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 component 42 arranged inside the heating tube shell, and fins 43 arranged on the outer surface of the heating tube shell 41 .

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

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

[0022] According to some specific embodiments of the present invention, the ceramic heating tube shell can withstand a high temperature exceeding 1200° C. for a long period of time.

[0023] The present invention uses ceramic material to make the outer shell of the heating tube. The high hardness of the ceramic material solves the problem that the outer surface of the electric heating tube 4 needs 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 spirally arranged around the heating tube shell 41 from top to bottom.

[0025] According to some specific embodiments of the present invention, the spiral angle of the fin 43 is 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 the present invention increase the disturbance of catalyst particles in the external heating device and the heat transfer area, thereby improving the heating efficiency of the electric power supply 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 arranged inside the heating tube housing 41 .

[0029] According to some specific embodiments of the present invention, the external heat supplement device 1 also includes a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for communicating with the catalytic cracking bed regenerator; the first catalyst delivery channel 5 is arranged at the upper part of the external heat supplement device 1, and the second catalyst delivery channel 6 is arranged at the lower part of the external heat supplement device 1.

[0030] According to some specific embodiments of the present invention, a horizontal turning structure 7 is provided inside the first catalyst delivery channel 5 at the connection with the external heat supply device 1 .

[0031] According to some specific embodiments of the present invention, the angle between the horizontal turning structure 7 and the conveying channel 5 is 30 degrees to 60 degrees.

[0032] According to some specific embodiments of the present invention, the height h of the horizontal turning structure 7 is ( Figure 1 h) is smaller than the pipe diameter ( Figure 1 1 / 4 of R in.

[0033] According to some specific embodiments of the present invention, a valve 8 is provided on the second catalyst delivery channel 6 .

[0034] According to some specific embodiments of the present invention, the valve 8 is a sliding valve.

[0035] According to some specific embodiments of the present invention, the external heat supplement device 1 is provided with a catalyst fluidization distributor 9 at the bottom of the inner cavity.

[0036] According to some specific embodiments of the present invention, 1-2 external heating devices 1 are provided.

[0037] On the other hand, the present invention also provides a catalytic cracking bed regeneration system, wherein the regeneration system includes a catalytic cracking bed regenerator 11 and an external heat supplement device 1 for the catalytic cracking bed regenerator according to the present invention; the external heat supplement device 1 is connected to the catalytic cracking bed regenerator 11 through a first catalyst delivery channel 5 and a second catalyst delivery channel 6.

[0038] According to some specific embodiments of the present invention, there are two external heat supplement devices 1 for the catalytic cracking bed regenerator, and they are symmetrically arranged on both sides of the catalytic cracking bed regenerator 11.

[0039] According to some specific embodiments of the present invention, two external heat supplement devices 1 are provided and are symmetrically distributed on both sides of the catalytic cracking bed regenerator 5 .

[0040] On the other hand, the present invention further provides a method for supplementing heat to a catalytic cracking bed regenerator, wherein the method comprises supplementing heat to the catalytic cracking bed regenerator using the external heat supplement device for the catalytic cracking bed regenerator as described in any one of the preceding items of the present invention.

[0041] According to some specific embodiments of the present invention, the linear velocity of the fluidizing gas in the external supplemental heat device 1 is 0.05-1 m / s.

[0042] According to some specific embodiments of the present invention, the linear velocity of the fluidizing gas in the external supplemental heat device 1 is 0.1-0.4 m / s.

[0043] According to some specific embodiments of the present invention, the operating temperature in the external heat supply device 1 is 650-950°C.

[0044] According to some specific embodiments of the present invention, the operating temperature in the external heat supply device 1 is 700-850°C.

[0045] According to some specific embodiments of the present invention, the density of the catalyst bed (i.e., the catalyst accumulation layer) in the external heating device 1 is 200-700 kg / m 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 / m 3 .

[0047] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 400-650 kg / m 3 .

[0048] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 450-650 kg / m 3 .

[0049] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 600-650 kg / m 3 .

[0050] According to some specific embodiments of the present invention, the circulation amount of catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator (referred to as catalyst circulation amount) is 0.05 to 1.0 times, preferably 0.1 to 0.5 times, of the catalyst circulation amount of the catalytic cracking regeneration system.

[0051] According to some specific embodiments of the present invention, the circulation amount of catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator is 0.25-0.35 times the circulation amount of catalyst in the catalytic cracking reverse regeneration system.

[0052] The catalytic cracking regeneration system of the present invention comprises a catalytic cracking bed regeneration system and a catalytic cracking reaction system (such as a riser reactor or a turbulent fluidized bed reactor).

[0053] The catalytic cracking bed regeneration system and the catalytic cracking reaction system can be conventional catalytic cracking bed regeneration system and catalytic cracking reaction system in the art.

[0054] According to some specific embodiments of the present invention, the heat compensation coefficient of the external heat compensation device 1 is 0.05-5.0.

[0055] According to some specific embodiments of the present invention, the heat compensation coefficient of the external heat compensation device 1 is 0.5-2.

[0056] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 600-650 kg / m 3 The circulation amount of catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator is 0.25-0.35 times the circulation amount of catalyst in the catalytic cracking reverse regeneration system.

[0057] According to some specific embodiments of the present invention, the catalyst bed density in the external heating device 1 is 650 kg / m 3 The circulation amount of catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator is 0.3 times the circulation amount of catalyst in the catalytic cracking reverse regeneration system.

[0058] The total heat supplement of the external heat supplement device 1 of the present invention = heat supplement coefficient * (heat requirement of catalytic cracking reactor - heat of coke combustion); the combustion heat of coke = coke combustion enthalpy × raw material processing volume × coke yield; the total power of the electric power supply heating device 2 of the external heat supplement device 1 is equal to the total heat supplement of the external heat supplement device per unit time.

[0059] In summary, the present invention provides a catalytic cracking bed regenerator external heat supplement device, system and method. The device of the present invention has the following advantages:

[0060] An electrically powered external heating device is used to provide external heating for the regenerated catalyst. No hydrothermal environment is generated in the external heating device, and structural deactivation of the catalyst can be avoided even under overheating conditions, thereby reducing catalyst consumption and achieving heat balance in the catalytic cracking reaction-regeneration system.

[0061] By using electricity to supply heat to the regenerated catalyst, instead of adding fuel oil or coal powder to burn to supplement heat, there is no additional carbon dioxide emission;

[0062] The present invention can efficiently transfer the heat energy converted from electrical energy to the regenerator and the catalytic cracking reactor by flexibly adjusting the catalyst bed density and the catalyst circulation multiple of the external heat supplement device, thereby realizing high-temperature regeneration of the catalyst to be regenerated and improving the efficiency of heat supplement to achieve energy saving effect.

[0063] The present 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;

[0064] The present invention arranges the supplementary heat device outside the regenerator, which can prevent the supplementary heat device from aging at high temperature, avoid the influence of the failure of the supplementary heat device on the regenerator, ensure the safe use of the equipment, and significantly extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of the external heat supplement device and the catalytic cracking bed regeneration system of Example 1 of the present invention.

[0066] Figure 2 It is an enlarged schematic diagram of the electric heating tube of Example 1 of the present invention. DETAILED DESCRIPTION

[0067] The implementation process of the present invention and the beneficial effects produced are described in detail below through specific embodiments, which is intended to help readers better understand the essence and characteristics of the present invention, and is not intended to limit the scope of implementation of the present invention.

[0068] Example 1

[0069] Using industrial production equipment, according to Figure 1The external heat supplement device of the catalytic cracking bed regenerator shown in the figure uses electric energy to supplement heat. The external heat supplement device includes: an external heat supplement device 1 with an electric energy heating device 2 and a catalyst fluidizing distributor 9 arranged inside, a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for delivering catalyst into and out of the external heat supplement device 1, a horizontal turning 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 bed regenerator 11.

[0070] The catalyst coming out of the catalytic cracking bed regenerator 11 enters the external heating device 1 through the first catalyst delivery channel 5 and the horizontal turning structure 7 at the outlet of the first catalyst delivery channel 5, and under the action of the catalyst fluidizing distributor 9 in the external heating device, a uniformly distributed catalyst particle bed is formed to fully exchange heat with the electric power supply heating device 2. The linear velocity of the fluidizing gas in the external heating device 1 is 0.24m / s; the operating temperature in the external heating device 1 is 800℃; the density of the catalyst bed is 420kg / m 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 circulation amount of the catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator 11 is 0.4 times the circulation amount of the catalyst in the catalytic cracking reverse regeneration system.

[0071] Taking a catalytic cracking unit for producing low-carbon olefins with a processing capacity of 100 tons / h of light hydrocarbons as an example, the coke yield is 3.17% (mass fraction), and the amount of coke burned in the regenerator per hour is 3.17 tons. The heat released by the combustion of coke is 1.14*10 8 kJ / h. The catalytic cracking reactor requires 3.2*10 8 kJ / h, in order to maintain the heat balance of the catalytic cracking device reaction-regeneration system, the heat supplement coefficient is preferably 1.18, and the total heat supplement of the external heat supplement device 1 = 1.18*(heat required by the catalytic cracking reactor - heat of coke combustion) = 2.8*10 8 kJ / h, the total power of the external heating device 1 is 77.78MW.

[0072] According to the total power of the external heating device 1, 20 electric heating tubes are set, and the power of each electric heating tube is 3.889MW. The electric heating tubes are connected in parallel and controlled separately by external control circuits to realize the electric heating tubes being powered on one by one, partially or completely for heating. Figure 2As shown, each electric heating tube 4 contains an electric heating component 42, a temperature sensor and an over-temperature protection component 44, and the electric heating component is required to withstand 1400°C; in order to solve the problem of wear on the outer surface of the electric heating tube 4 under high temperature and catalyst fluidization state, the outside 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 provided with fins 43 (the spiral angle is 30°, and the width is 0.2 times the diameter of the heating tube shell 41) to increase the disturbance of the catalyst particles in the supplementary heat device and the heat transfer area, thereby improving the heating efficiency of the electric power heating device.

[0073] The working conditions in the external heating device 1 of Example 1 are shown in Table 1:

[0074] Table 1 Main working conditions of external heating device

[0075] Example 1 Comparative Example 1 Heater pressure, MPa(A) 0.31 0.33 Heater operating temperature, ℃ 800 680 Fluidizing gas linear velocity of supplementary heat exchanger, m / s 0.24 0.25 Catalyst circulation volume of supplementary heat unit / catalyst circulation volume of reverse regeneration system 0.4 - Oxygen content in outlet flue gas, v% No smoke generation 0.5 Fuel to catalyst ratio No fuel used 1:6-500 Will it increase carbon dioxide emissions? none have

[0076] It can be seen from the data in Table 1 that Example 1 and the comparative example data in Table 1 are from invention patent CN201510833567.1. Compared with other current reheater methods (reheater, catalytic cracking regeneration device and external heat supply method. Invention patent CN201510833567.1), the use of an electrically powered reheater to externally heat the regenerated catalyst can enable the reheater to operate at a higher temperature, and no hydrothermal environment is generated in the reheater, no smoke is generated, and no additional carbon dioxide emissions are emitted.

[0077] Example 2

[0078] Using the experimental pilot plant, according to Figure 1 The external heat supplement device of the catalytic cracking bed regenerator shown in the figure uses electric energy to supplement heat. The external heat supplement device includes: an external heat supplement device 1 with an electric energy heating device 2 and a catalyst fluidizing distributor 9 arranged inside, a first catalyst delivery channel 5 and a second catalyst delivery channel 6 for delivering catalyst into and out of the external heat supplement device 1, a horizontal turning 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 bed regenerator 11.

[0079] The catalyst coming out of the catalytic cracking bed regenerator 11 enters the external heating device 1 through the first catalyst delivery channel 5 and the horizontal turning structure 7 at the outlet of the first catalyst delivery channel, and under the action of the catalyst fluidizing distributor 9 in the external heating device 1, a uniformly distributed catalyst particle bed is formed to fully exchange heat with the electric power supply heating device 2. The linear velocity of the fluidizing gas in the external heating device 1 is 0.30m / s; the operating temperature in the external heating device 1 is 900℃; the density of the catalyst bed is 540kg / m by adjusting the linear velocity of the fluidizing gas in the external heating device 1. 3By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the circulation amount of the catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator 11 is 0.2 times the circulation amount of the catalyst in the catalytic cracking reverse regeneration system.

[0080] Taking the pilot plant of catalytic cracking to produce light olefins with a processing capacity of 10 kg / h naphtha as an example, the coke yield is 3.68% (mass fraction), and the amount of coke burned in the regenerator per hour is 0.368 kg. The heat released by the combustion of coke is 1.32*10 4 kJ / h. The catalytic cracking reactor requires 2.76*10 4 kJ / h, in order to maintain the heat balance of the reaction-regeneration system of the catalytic cracking unit, the heat supplement coefficient is preferably 2.0, and the total heat supplement of the external heat supplement device 1 = 2.0*(heat required by the catalytic cracking reactor - heat of coke combustion) = 2.88*10 4 kJ / h, the total power of the external heating device 1 is 8MW.

[0081] According to the total power of the external heating device 1, 10 electric heating tubes are set, and the power of each electric heating tube is 0.8MW. The electric heating tubes are connected in parallel and controlled separately by external control circuits to realize the heating of the electric heating tubes one by one, partially or completely. Each electric heating tube 4 contains an electric heating component 42, a temperature sensor and an over-temperature protection component 44. The electric heating component is required to withstand 1400°C; in order to solve the problem of wear on the outer surface of the electric heating tube 4 under high temperature and catalyst fluidization state, the outside of the electric heating tube 4 is a ceramic heating tube shell 41; the ceramic shell 41 outside the electric heating tube 4 can be provided with fins 43 (the spiral angle is 45°, and the width is 0.25 times the diameter of the heating tube shell 41) to increase the disturbance of the catalyst particles in the heater and the heat transfer area, thereby improving the heating efficiency of the electric power heating device.

[0082] In view of the fact that catalytic cracking is a deep catalytic cracking reaction mode, in order to compare the effect of Example 2 on the catalyst and product yield, other current heat supplementation methods (a catalyst regeneration method and equipment for supplementing the heat of a catalytic cracking unit. Invention patent CN201110272641.9) are selected. The data of the comparative examples in Table 2-4 are from the invention patent CN201110272641.9. Example 2 is used in a pilot plant for catalytic cracking of light olefins with a processing capacity of 10kg / h naphtha for testing, and naphtha is also used as the catalytic cracking raw material. The raw material properties are shown in Table 2. Compared with the comparative example, the properties of the raw material of Example 2 are slightly worse, which is manifested in a slightly lower content of paraffins and a higher content of aromatics.

[0083] Table 2 Naphtha raw material properties

[0084] Example 2 Comparative Example 2 <![CDATA[Density (20 °C), g / cm 3 > 0.7379 0.7358 Vapor pressure, kPa 49.0 50.0 Group composition, w% Alkanes 49.52 51.01 Cycloalkanes 38.63 38.24 Olefins 0.11 0.12 Aromatics 11.74 10.52 Distillation range,℃ IBP 46 46 10％ 89 87 30％ 108 107 50％ 122 120 70％ 134 133 90％ 151 149 95％ 156 155

[0085] Table 3 is a comparison of catalyst properties. Since no hydrothermal environment is generated in the supplementary heat vessel, structural deactivation of the catalyst can be avoided even under overheating conditions. Therefore, the pore volume and specific surface area of ​​the catalyst in Example 2 are significantly increased compared with those in the comparative example, and the proportion of catalyst particles smaller than 40 um is significantly reduced, which is beneficial to improving the effect of the catalytic cracking reaction.

[0086] Table 3 Catalyst properties

[0087]

[0088]

[0089] Table 4 is a comparison of operating conditions and product distribution. The regenerated catalyst is heated by electric energy supply instead of adding fuel oil combustion to supplement heat in the comparative example, and no additional carbon dioxide emissions are emitted. The temperature of the catalyst in the regenerator can be quickly and accurately controlled by adjusting the current or voltage, so that the regeneration temperature is significantly increased. The catalyst properties and improvements and reactor process conditions can be flexibly adjusted to significantly increase the yield of the target product ethylene + propylene.

[0090] Table 4 Operating conditions and product distribution

[0091]

[0092]

[0093] Example 3

[0094] In order to verify that the present invention can better ensure sufficient heat capacity to achieve efficient heat transfer by controlling the circulation amount of catalyst between the external heat supplement device and the catalytic cracking bed regenerator, thereby adjusting the bed density in the external heat supplement device, a single factor experimental comparison was carried out between Example 3 and Example 1 of the present invention.

[0095] Using industrial production equipment, according to Figure 1 The catalytic cracking bed regenerator shown in the figure uses an external heat supplement device for electrical energy to supplement heat. The method of Example 1 is adopted. The linear velocity of the fluidizing gas in the external heat supplement device 1 is 0.24 m / s; the operating temperature in the external heat supplement device 1 is 800°C; the catalyst bed density is 520 kg / m by adjusting the linear velocity of the fluidizing gas in the external heat supplement device 1. 3 By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the circulation amount of the catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator 11 is 0.4 times the circulation amount of the catalyst in the catalytic cracking reverse regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a processing capacity of 100 tons / h of light hydrocarbons as an example, the coke yield is 3.17% (mass fraction), and the amount of coke burned in the regenerator per hour is 3.17 tons. The heat released by the combustion of coke is 1.14*10 8kJ / h. The catalytic cracking reactor requires 3.2*10 8 kJ / h, in order to maintain the heat balance of the reaction-regeneration system of the catalytic cracking device when using Example 1, the heat supplement coefficient is 1.18, and the total heat supplement of the external heat supplement device 1 = 1.18*(heat required by the catalytic cracking reactor - heat of coke combustion) = 2.8*10 8 kJ / h, the total power of the external heating device 1 is 77.78MW.

[0096] Using industrial production equipment, according to Figure 1 The heat supplement of the external heating device of the catalytic cracking bed regenerator using electrical energy is shown in the figure. The following method is used: the linear velocity of the fluidizing gas in the external heating device 1 is 0.24 m / s; the operating temperature in the external heating device 1 is 800°C; the density of the catalyst bed is 650 kg / m 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 circulation amount of the catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator 11 is 0.3 times the circulation amount of the catalyst in the catalytic cracking reverse regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a processing capacity of 100 tons / h of light hydrocarbons as an example, the coke yield is 3.17% (mass fraction), and the amount of coke burned in the regenerator per hour is 3.17 tons. The heat released by the combustion of coke is 1.14*10 8 kJ / h. The catalytic cracking reactor requires 3.2*10 8 kJ / h. When using Example 3, in order to maintain the heat balance of the reaction-regeneration system of the catalytic cracking device, the heat supplement coefficient is 1.0, and the total heat supplement of the external heat supplement device 1 = 1.0*(heat required by the catalytic cracking reactor - heat of coke combustion) = 2.37*10 8 kJ / h, the total power of the external heating device 1 is 65.91MW.

[0097] By adjusting the bed density in the external supplementary heat device through the present invention, the heating power of the supplementary heat device can be greatly reduced, and sufficient catalyst heat capacity can be guaranteed to achieve efficient heat transfer.

[0098] Comparative Example

[0099] Using industrial production equipment, according to Figure 1 The catalytic cracking bed regenerator shown in the figure uses an external heat supplement device for heat supplementation, the fluidizing gas linear velocity in the external heat supplement device 1 is 0.24m / s; the operating temperature in the external heat supplement device 1 is 800℃; the catalyst bed density is 150kg / m by adjusting the fluidizing gas linear velocity in the external heat supplement device 1 3By adjusting the opening of the slide valve 8 on the second catalyst delivery channel 6, the circulation amount of the catalyst between the external heat supply device 1 and the catalytic cracking bed regenerator 11 is 0.1 times the circulation amount of the catalyst in the catalytic cracking reverse regeneration system. Taking a catalytic cracking unit for producing low-carbon olefins with a processing capacity of 100 tons / h of light hydrocarbons as an example, the coke yield is 3.17% (mass fraction), and the amount of coke burned in the regenerator per hour is 3.17 tons. The heat released by the combustion of coke is 1.14*10 8 kJ / h. The catalytic cracking reactor requires 3.2*10 8 kJ / h. In order to maintain the heat balance of the reaction-regeneration system of the catalytic cracking unit, the heat supplement coefficient is 1.41, and the total heat supplement of the external heat supplement device 1 = 1.41*(heat required by the catalytic cracking reactor - heat of coke combustion) = 2.91*10 8 kJ / h, the total power of the external heating device 1 is 79.30MW.

[0100] Table 5 shows that the optimization of catalyst bed density and circulation volume has played a significant role in improving catalyst performance and the yield of light olefins through the data of industrial production device Example 1, Example 3 and Comparative Example 3. Among them, in Example 3, the ethylene + propylene yield reached 56.34%, which is significantly higher than other operating conditions. In addition, the catalyst pore volume and specific surface area in the embodiment are significantly better than those in the comparative example, indicating that the optimized parameter setting significantly enhances the catalyst regeneration effect and stability. In general, the efficient heat supplement support provided by the external heat supplement device, especially at higher catalyst bed density and circulation volume, significantly improves the reaction efficiency and achieves energy saving effect.

[0101] Table 5 Main working conditions and product distribution of external heating device

[0102]

[0103]

[0104] In the present invention, the catalysts in the embodiments and comparative examples are from the same batch of catalysts with the same parameters, and other parameters of the catalysts in industrial production are also the same. The difference between the embodiments and comparative examples is only the difference in the parameter settings of the regenerator external heat supply device in Table 5, so as to eliminate the influence of other factors other than these parameters.

Claims

1. A catalytic cracking bed regenerator external heat supplement device, wherein: The external heating device (1) comprises an electrically powered heating device (2) and a housing (3); the electrically powered heating device (2) is composed of a plurality of electric heating tubes (4) (preferably 2 to 30 tubes).

2. The external heating device according to claim 1, wherein: The electric heating tube (4) comprises a heating tube shell (41) (preferably a ceramic heating tube shell), an electric heating component (42) arranged inside the heating tube shell, and fins (43) arranged on the outer surface of the heating tube shell (41) (preferably the fins (43) are arranged in a spiral arrangement around the heating tube shell (41) from top to bottom).

3. The external heating device according to claim 2, wherein: The electric heating tube (4) also includes a temperature sensor and an over-temperature protection component (44) arranged inside the heating tube shell (41).

4. The external heating device according to any one of claims 1 to 3, wherein: The external heat supplement device (1) is provided with a catalyst fluidizing distributor (9) at the bottom of the inner cavity.

5. The external heating device according to any one of claims 1 to 4, wherein: The external heat supply device (1) further comprises a first catalyst delivery channel (5) and a second catalyst delivery channel (6) for communicating with the catalytic cracking bed regenerator; the first catalyst delivery channel (5) is arranged at the upper part of the external heat supply device (1), and the second catalyst delivery channel (6) is arranged at the lower part of the external heat supply device (1) (preferably, a horizontal turning structure (7) is arranged inside the first catalyst delivery channel (5) at the connection with the external heat supply device (1)) (more preferably, a valve (8) is arranged on the second catalyst delivery channel (6)).

6. A catalytic cracking bed regeneration system, wherein: The regeneration system comprises a catalytic cracking bed regenerator (11) and an external heat supplement device (1) for the catalytic cracking bed regenerator according to claim 5; the external heat supplement device (1) is connected to the catalytic cracking bed regenerator (10) through a first catalyst delivery channel (5) and a second catalyst delivery channel (6) (preferably, there are two external heat supplement devices (1) for the catalytic cracking bed regenerator, which are symmetrically arranged on both sides of the catalytic cracking bed regenerator (11)).

7. A method for supplementing heat in a catalytic cracking bed regenerator, wherein: The method comprises using the catalytic cracking bed regenerator external heat supplement device as claimed in any one of claims 1 to 5 to supplement the heat of the catalytic cracking bed regenerator.

8. The method according to claim 7, wherein: The linear velocity of the fluidizing gas in the external supplemental heat device (1) is 0.05-1 m / s (preferably 0.1-0.4 m / s).

9. The method according to claim 7 or 8, wherein: The operating temperature in the external supplementary heat device (1) is 650-950°C (preferably 700-850°C).

10. The method according to any one of claims 7 to 9, wherein: The catalyst bed density in the external heating device (1) is 200-700 kg / m 3 (Preferably 300 to 650 kg / m 3 ).

11. The method according to any one of claims 7 to 10, wherein: The circulation amount of the catalyst between the external heat supply device (1) and the catalytic cracking bed regenerator is 0.05 to 1.0 times (preferably 0.1 to 0.5 times) the circulation amount of the catalyst in the catalytic cracking regeneration system.

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