Catalyst heat exchange and replacement device, catalytic cracking reaction system and catalytic cracking method

Abstract

The invention provides a catalyst heat exchange and replacement device, a catalytic cracking reaction system and a catalytic cracking method. The method provided by the invention solves the technical problems of large catalyst storage amount and long replacement period of a large catalytic device and further improvement of the flexible adjustment range of the catalytic cracking reaction, realizes flexible switching among different product schemes such as maximum production of chemical materials, consideration of the chemical materials and oil products, maximum production of the oil products and the like, and has a wide application prospect. The method is a novel catalytic cracking technology with flexibly adjustable product structure.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, specifically relating to a catalyst heat exchange and replacement device, a catalytic cracking reaction system, and a catalytic cracking method. Background Technology

[0002] In recent years, global refining capacity has continued to grow, but the industry's development has been affected by factors such as the global economic downturn and geopolitical conflicts, resulting in a slowdown in overall demand growth. Product demand and production profits have shown an unprecedented trend of "oil refining being weak and chemical refining being weak." Currently, the refining industry is facing a situation of accelerating the "reduction of oil refining and increase of chemical and specialty products," with continuous optimization of product structure adjustments. How refineries can flexibly adjust their product structure to closely follow the market and respond quickly is key to the profitability of refining enterprises. Developing catalytic cracking technology that can adapt to the diversity of processing raw materials and flexibly adjust product structure can achieve flexible switching between different product models such as oil products and chemical products, and has good prospects for industrial application.

[0003] Some well-known international oil companies have proposed the concept of a gas-solid ultra-short contact downflow bed reactor, believing that shortening the residence time of oil and gas helps improve the selectivity of intermediate products such as propylene, and have begun to develop new downflow bed reactor catalytic cracking technologies. Patent CN1113659 discloses a flexible folded design using a riser-coupled downflow bed, capable of producing low-carbon olefins and clean gasoline. Patent US6656346B2 discloses a high-severity catalytic cracking process HS-FCC (High-Severity Fluid Catalytic Cracking), which uses a downflow bed reactor to conduct catalytic cracking reactions under high severity, achieving a propylene yield of over 20%, while maintaining lower yields of dry gas and coke. This technology has two operating modes: producing more light olefins and producing more high-octane gasoline.

[0004] Domestic catalytic cracking processes mainly employ riser reactors. Patent CN1237477A discloses a variable-diameter fluidized bed (MIP) technology, developed by the China Petroleum & Chemical Research Institute Co., Ltd., and is the most widely used catalytic cracking technology in China, primarily for producing high-octane, low-olefin gasoline. This technology is based on a dual-reaction-zone conversion concept, employing a fast-bed reactor in the second reaction zone to promote hydrogen transfer and achieve controllable reductions in gasoline olefin content. To flexibly change the product structure, relying on the MIP technology platform, the China Petroleum & Chemical Research Institute Co., Ltd. developed the CGP technology, which reduces gasoline olefin content while significantly increasing propylene yield. Patent CN112536001A discloses a catalytic cracking RTC technology that utilizes a fast-bed reactor to increase propylene production, achieving propylene yields of over 18%. Flexible adjustment of the product structure requires rapidly matching and adapting catalysts. Patent CN1267706A discloses a catalyst replacement method, but it does not consider the drastic disturbance to the thermal balance caused by large-scale catalyst replacement, making it difficult to achieve stable reaction operation.

[0005] The current chemical and refined oil markets are changing rapidly. As one of the main units for producing chemicals and gasoline / diesel, catalytic cracking needs to quickly switch its product structure to seize market opportunities, but the following problems exist:

[0006] (1) Long replacement cycle: With the increase in large-scale catalytic devices and the large amount of catalyst stored in the system, there is a problem that conventional replacement techniques for formulation catalysts have a long cycle. It takes at least 1 to 3 months for the replacement period to show a good product structure adjustment effect.

[0007] (2) Limited scope of product structure adjustment: Existing catalytic cracking units face technical challenges in adjusting product structure, such as limiting the yield of target products and affecting the thermal balance of the unit. Adjusting the catalyst formulation will affect product distribution, especially coke yield. Coke will significantly affect the thermal balance of the regeneration system. Conventional external heat exchangers have limited operating load and are difficult to adapt to rapid and large-scale adjustments.

[0008] Therefore, it is essential to develop new catalytic cracking technologies that allow for rapid and flexible adjustment of product structures. Summary of the Invention

[0009] The purpose of this invention is to solve the technical problems of large catalyst reserves, long replacement cycles, and further improve the flexibility of catalytic cracking reaction adjustment in large-scale catalytic devices.

[0010] A first aspect of the present invention provides a catalyst heat exchange and replacement device, the catalyst heat exchange and replacement device having an outer cylinder, the outer cylinder housing a heat exchange coil, the heat exchange coil being provided with a heat exchange medium inlet and a heat exchange medium outlet, the heat exchange medium inlet and the heat exchange medium outlet being disposed outside the outer cylinder;

[0011] The heat exchange coil is connected to the fluidized medium pipeline of the displacement catalyst. The fluidized medium pipeline of the displacement catalyst is equipped with a fluidized medium inlet valve of the displacement catalyst. The fluidized medium inlet valve of the displacement catalyst is located outside the outer cylinder and close to the outlet side of the heat exchange medium.

[0012] The outer cylinder is provided with one or more inner cylinders. The bottom of the inner cylinder is provided with a displacement catalyst inlet, which is connected to the displacement catalyst fluidizing medium pipeline. The top of the inner cylinder is provided with a displacement catalyst outlet, which is connected to the displacement catalyst discharge pipeline. The heat exchange coil is located below the one or more inner cylinders.

[0013] The fluidized medium pipeline for the displacement catalyst is also provided with a displacement catalyst inlet, which is connected to the displacement catalyst addition pipeline and is located downstream of the fluidized steam inlet valve.

[0014] The outer cylinder is also equipped with a regenerated catalyst fluidized medium inlet, a catalyst unloading pipeline, a regenerated catalyst heat exchange inlet, and a regenerated catalyst heat exchange outlet.

[0015] The regenerated catalyst fluidized medium inlet, catalyst unloading pipeline, and regenerated catalyst heat exchanger are located at the lower part of the external heat exchanger, and are all located below the heat exchange coil.

[0016] According to the catalyst heat exchange and replacement device of the first aspect, the outer cylinder of the catalyst heat exchange and replacement device is cylindrical with a height-to-diameter ratio of 0.1-20; and / or

[0017] The diameter of the heat exchange coil is 0.01-0.1 times the outer cylinder diameter.

[0018] According to the catalyst heat exchange and replacement device of the first aspect, the inner cylinder has a diameter of 0.05-0.4 times that of the outer cylinder, and a height-to-diameter ratio of 0.1-20;

[0019] Preferably, the number of inner cylinders is 4-10.

[0020] A second aspect of the present invention provides a catalytic cracking reaction system, comprising:

[0021] The reactor is equipped with a reaction oil and gas inlet, a reactor fluidized medium inlet, a catalyst inlet, an oil and gas separation device, a product oil and gas outlet, and a catalyst outlet. The oil and gas separation device includes a cyclone separator and a stripper.

[0022] A regenerator, used for regenerating the catalyst to be generated, is equipped with a regenerating inclined tube, a regeneration medium inlet, a flue gas outlet, a regenerating catalyst heat exchange outlet, a regenerating catalyst heat exchange return inlet, a replacement catalyst inlet, and a regeneration inclined tube. The regenerating inclined tube is connected to the regenerating catalyst outlet of the reactor, and the regeneration inclined tube is connected to the catalyst inlet of the reactor.

[0023] A catalyst heat exchange and replacement device in the first aspect is used to heat and replace the regenerated catalyst. The catalyst replacement outlet line of the catalyst heat exchange and replacement device is connected to the catalyst replacement inlet of the regenerator. The regenerated catalyst heat exchange inlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange outlet of the regenerated catalyst. The regenerated catalyst heat exchange outlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange return inlet of the regenerator.

[0024] According to the catalyst heat exchange and replacement device of the first aspect, the reactor is a fluidized bed reactor;

[0025] Preferably, the fluidized bed reactor is selected from one or more of the following: riser reactor, fast bed reactor, turbulent bed reactor, and downflowing bed reactor.

[0026] A third aspect of the present invention provides a catalytic cracking method, wherein the catalytic cracking reaction system of the second aspect of the catalytic cracking method comprises:

[0027] Fluidized medium enters the reactor from the bottom, and catalyst from the regenerator enters the reactor. The feedstock oil and gas and the catalyst react in the reactor. The resulting oil and gas products are separated from the spent catalyst at the end of the reactor. The separated oil and gas products are led out of the reactor. The spent catalyst is stripped and then enters the regenerator for regeneration. The regenerated catalyst enters the outer cylinder of the catalyst heat exchange replacement device to exchange heat with the heat exchange medium in the heat exchange coil. Under the action of the fluidized medium of the regenerated catalyst, it returns to the regenerator through the heat exchange outlet of the regenerated catalyst and then enters the reactor through the regeneration inclined tube set at the bottom of the regenerator for recycling reaction.

[0028] During catalyst replacement, the regenerated catalyst enters the outer cylinder of the catalyst heat exchanger and replacement device for heat exchange. Then, 10%-80% of the catalyst is discharged through the catalyst unloading pipeline of the catalyst heat exchanger and replacement device. The replacement catalyst enters the inner cylinder of the catalyst heat exchanger and replacement device through the replacement catalyst inlet under the action of the replacement catalyst fluidizing medium and completes heat exchange. It then enters the regenerator through the replacement catalyst outlet pipeline to mix with the regenerated catalyst for a cyclic reaction.

[0029] According to the method of the third aspect, the operating conditions of the reactor are as follows:

[0030] The reaction temperature is 500-800℃;

[0031] The reaction pressure is 0.1-2.0 MPa;

[0032] The agent-to-oil ratio is 5-40;

[0033] The dwell time is 1.0-15.0 seconds.

[0034] According to the method of the third aspect, the outer cylinder of the catalyst heat exchanger is a fluidized bed with a linear velocity of 0.1-2 m / s; and / or

[0035] The fluidizing medium for the regenerated catalyst is selected from one or more of air, dry gas, and water vapor.

[0036] According to the third method, the heat exchange medium generates superheated steam after heat exchange through the heat exchange coil. The superheated steam enters the inner cylinder through the fluidized medium pipeline for replacing the catalyst, and is used to fluidize and replace the catalyst and perform heat exchange.

[0037] Preferably, the heat exchange medium is water at 0-100°C;

[0038] More preferably, the inlet flow velocity of the heat exchange medium is 1-10 m / s.

[0039] According to the method of the third aspect, the linear velocity of the catalyst being replaced in the inner cylinder of the catalyst heat exchanger is 0.1-2 m / s; and / or

[0040] The replacement catalyst is heated to 300-500℃ and then enters the regenerator.

[0041] According to the method of the third aspect, the regeneration temperature in the regenerator is 550-850℃; and / or

[0042] The regeneration medium is one or more of air and pure oxygen.

[0043] According to the method of the third aspect, the feedstock oil and gas is selected from one or more of heavy distillate oil, gasoline, and diesel;

[0044] Preferably, the raw materials are preheated before entering the reactor, and the preheating temperature is preferably 100-300℃.

[0045] Compared with the prior art, the present invention has the following technical effects:

[0046] (1) Wide heat exchange load: Compared with conventional external heat exchangers, the present invention uses a catalyst replacement device, and the inner cylinder can be adjusted between dense phase fluidized bed and dilute phase fluidized bed. The catalyst particle solid content adjustment range is wide, so the heat exchange load range is wide, thus it can adapt to a wider range of product structure adjustments.

[0047] (2) High heat exchange efficiency. By using the heat of the original regenerated catalyst to heat the new catalyst, heat is recovered on the one hand, and the temperature fluctuation of the new low-temperature catalyst on the regeneration system is reduced on the other hand.

[0048] (3) It has strong adaptability to raw materials, a wide range of heat loads for catalyst replacement devices, and a fast heat exchange rate. It can be applied to raw materials with different coke yields. It is not only suitable for light catalytic cracking raw materials such as hydrogenated LCO, but also for deep catalytic cracking processes of inferior heavy raw materials with high density and low hydrogen content.

[0049] (4) Fast heat exchange rate. This invention can achieve rapid replacement of catalyst system in large-scale catalytic cracking unit. Compared with conventional replacement methods, this method can increase the replacement rate by 2-20 times. Attached Figure Description

[0050] Figure 1 A schematic diagram of the process flow according to an embodiment of the present invention is shown.

[0051] Figure 2 A schematic diagram of the inner cylinder arrangement described in this invention is shown. Figure 2 (a) shows the arrangement of four inner cylinders in Embodiment 1. Figure 2 (b) shows the arrangement of eight inner cylinders in Embodiment 2.

[0052] Explanation of reference numerals in the attached figures:

[0053] 1. Fluidizing medium; 2. Gas distribution plate; 3. Regeneration slide valve; 4. Oil inlet nozzle; 5. Riser reaction section; 6. Cyclone separator; 7. Stripper; 8. Product oil and gas discharge pipeline; 9. Stripping medium; 10. Waiting slide valve; 11. Regenerator; 12. Regenerator cyclone separator; 13. Flue gas outlet pipeline; 14. Regeneration medium; 15. Cold regenerator replacement slide valve; 16. Hot regenerator replacement slide valve; 17. Catalyst heat exchanger replacement device outer cylinder; 18. Catalyst heat exchanger replacement device inner cylinder; 19. Replacement catalyst addition pipeline; 20. Replacement catalyst discharge pipeline; 21. Heat exchange medium inlet; 22. Heat exchange medium outlet; 23. Heat exchange coil; 24. Replacement catalyst fluidizing medium inlet valve; 25. Regenerated catalyst fluidizing medium; 26. Catalyst unloading pipeline. Detailed Implementation

[0054] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0055] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0056] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0057] Any specific numerical values ​​disclosed herein (including the endpoints of numerical ranges) are not limited to their exact values, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Furthermore, with respect to the disclosed numerical ranges, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values ​​themselves; these new numerical ranges should also be considered as specifically disclosed herein.

[0058] In this application, the terms "upstream" and "downstream" refer to the direction of reaction material flow. For example, when the reaction material flows from bottom to top, "upstream" refers to the position at the bottom, while "downstream" refers to the position at the top.

[0059] Unless otherwise stated, the terms used herein have the same meaning as commonly understood by those skilled in the art, and if a term is defined herein and its definition differs from the common understanding in the art, the definition herein shall prevail.

[0060] The present invention provides a catalyst heat exchange and replacement device, the catalyst heat exchange and replacement device having an outer cylinder, the outer cylinder containing a heat exchange coil, the heat exchange coil being provided with a heat exchange medium inlet and a heat exchange medium outlet, the heat exchange medium inlet and the heat exchange medium outlet being located outside the outer cylinder;

[0061] The heat exchange coil is connected to the fluidized medium pipeline of the displacement catalyst. The fluidized medium pipeline of the displacement catalyst is equipped with a fluidized medium inlet valve of the displacement catalyst. The fluidized medium inlet valve of the displacement catalyst is located outside the outer cylinder and close to the outlet side of the heat exchange medium.

[0062] The outer cylinder is provided with one or more inner cylinders. The bottom of the inner cylinder is provided with a displacement catalyst inlet, which is connected to the displacement catalyst fluidizing medium pipeline. The top of the inner cylinder is provided with a displacement catalyst outlet, which is connected to the displacement catalyst discharge pipeline. The heat exchange coil is located below the one or more inner cylinders.

[0063] The fluidized medium pipeline for the displacement catalyst is also provided with a displacement catalyst inlet, which is connected to the displacement catalyst addition pipeline and is located downstream of the fluidized steam inlet valve.

[0064] The outer cylinder is also equipped with a regenerated catalyst fluidized medium inlet, a catalyst unloading pipeline, a regenerated catalyst heat exchange inlet, and a regenerated catalyst heat exchange outlet.

[0065] The regenerated catalyst fluidized medium inlet, catalyst unloading pipeline, and regenerated catalyst heat exchanger are located at the lower part of the external heat exchanger, and are all located below the heat exchange coil.

[0066] In this invention, the catalyst fluidized medium inlet, catalyst unloading pipeline, and regenerated catalyst heat exchange inlet are located at the lower part of the external heat exchanger, and all are situated below the heat exchange coil, thereby ensuring that the regenerated catalyst entering the catalyst heat exchange and replacement device can fully exchange heat with the heat exchange coil. Simultaneously, this region is the dense phase zone of the fluidized bed, which facilitates rapid, large-volume unloading, thereby increasing the replacement rate.

[0067] In one embodiment, the outer cylinder of the catalyst heat exchanger is cylindrical with a height-to-diameter ratio of 0.1-20; and / or

[0068] The diameter of the heat exchange coil is 0.01-0.1 times the outer cylinder diameter.

[0069] The preferred diameter of the heat exchange coil in this invention is 0.01-0.1 times the outer cylinder diameter. When the diameter of the heat exchange coil is less than 0.01 times the outer cylinder diameter, the flow of the heat exchange medium inside the coil will be constrained by the friction of the pipe wall, increasing the flow resistance of the heat exchange medium inside the pipe, thereby reducing the velocity inside the pipe and decreasing the heat transfer efficiency. When the diameter of the heat exchange coil is greater than 0.1 times the outer cylinder diameter, the excessively large diameter of the heat exchange coil will cause the velocity distribution of the heat exchange medium inside the pipe to become uneven, reducing the contact area between the fluid and the pipe. Furthermore, an excessively large diameter will affect the fluidization of the catalyst inside the outer cylinder, hindering heat transfer. In one embodiment, the diameter of the inner cylinder is 0.05-0.4 times the outer cylinder diameter, and the height-to-diameter ratio is 0.1-20.

[0070] Preferably, the number of inner cylinders is 4-10.

[0071] The inner cylinder diameter of this invention is 0.05-0.4 times the outer cylinder diameter. When the inner cylinder diameter is less than 0.05 times the outer cylinder diameter, the inner cylinder diameter is too small, which increases the resistance to the flow of the replacement catalyst entering the inner cylinder and may even cause blockage of the replacement catalyst inside the cylinder. When the inner cylinder diameter is greater than 0.4 times the outer diameter, the outer cylinder can accommodate fewer inner cylinders, and the flow velocity distribution of the replacement catalyst inside the inner cylinder is uneven, which cannot carry out sufficient heat exchange and affects the thermal balance inside the regenerator after entering the regenerator.

[0072] The present invention also provides a catalytic cracking reaction system, comprising:

[0073] The reactor is equipped with a reaction oil and gas inlet, a reactor fluidized medium inlet, a catalyst inlet, an oil and gas separation device, a product oil and gas outlet, and a catalyst outlet. The oil and gas separation device includes a cyclone separator and a stripper.

[0074] A regenerator, used for regenerating the catalyst to be generated, is equipped with a regenerating inclined tube, a regeneration medium inlet, a flue gas outlet, a regenerating catalyst heat exchange outlet, a regenerating catalyst heat exchange return inlet, a replacement catalyst inlet, and a regeneration inclined tube. The regenerating inclined tube is connected to the regenerating catalyst outlet of the reactor, and the regeneration inclined tube is connected to the catalyst inlet of the reactor.

[0075] The aforementioned catalyst heat exchange and replacement device is used to exchange heat and replace the regenerated catalyst. The replacement catalyst outlet pipeline of the catalyst heat exchange and replacement device is connected to the replacement catalyst inlet of the regenerator. The regenerated catalyst heat exchange inlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange outlet of the regenerated catalyst. The regenerated catalyst heat exchange outlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange return inlet of the regenerator.

[0076] In one embodiment, the reactor is a fluidized bed reactor;

[0077] Preferably, the fluidized bed reactor is selected from one or more of the following: riser reactor, fast bed reactor, turbulent bed reactor, and downflowing bed reactor.

[0078] The present invention further provides a catalytic cracking method, wherein the catalytic cracking method uses the aforementioned catalytic cracking reaction system, comprising:

[0079] Fluidized medium enters the reactor from the bottom, and catalyst from the regenerator enters the reactor. The feedstock oil and gas and the catalyst react in the reactor. The resulting oil and gas products are separated from the spent catalyst at the end of the reactor. The separated oil and gas products are led out of the reactor. The spent catalyst is stripped and then enters the regenerator for regeneration. The regenerated catalyst enters the outer cylinder of the catalyst heat exchange replacement device to exchange heat with the heat exchange medium in the heat exchange coil. Under the action of the fluidized medium of the regenerated catalyst, it returns to the regenerator through the heat exchange outlet of the regenerated catalyst and then enters the reactor through the regeneration inclined tube set at the bottom of the regenerator for recycling reaction.

[0080] During catalyst replacement, the regenerated catalyst enters the outer cylinder of the catalyst heat exchanger and replacement device for heat exchange. Then, 10%-80% of the catalyst is discharged through the catalyst unloading pipeline of the catalyst heat exchanger and replacement device. The replacement catalyst enters the inner cylinder of the catalyst heat exchanger and replacement device through the replacement catalyst inlet under the action of the replacement catalyst fluidizing medium and completes heat exchange. It then enters the regenerator through the replacement catalyst outlet pipeline to mix with the regenerated catalyst for a cyclic reaction.

[0081] The working principle of this invention is as follows: fluidizing gas flows into the fluidized bed reactor from the bottom, and catalytic cracking catalyst from the regenerator enters the reactor from the upper part of the distribution plate. The fluidizing medium mixes with the flowing catalyst after passing through the distribution plate. The feedstock oil, after preheating, enters the bottom of the fluidized bed reactor through nozzles and mixes with the catalyst. The feedstock oil and catalyst then undergo a rapid cracking reaction in the fluidized bed reactor. Finally, the reactant oil and catalyst are rapidly separated at the end of the reactor. The separated, unregenerated catalyst is stripped and then enters the regenerator for coke burn-off regeneration. The regenerated catalyst enters the outer cylinder of the catalyst replacement device, which is equipped with a heat exchange coil at the bottom. After heat exchange, the regenerated catalyst returns to the regenerator and then back to the reactor for the next cycle. To achieve rapid switching between different operating modes, a catalyst compatible with the mode is required. When switching operating modes, a portion of the original regenerated catalyst enters the outer cylinder of the catalyst replacement device for fluidization. Hot water flows into the heat exchange coil to generate superheated steam. The superheated steam, as the fluidization medium, enters the inner cylinder to fluidize the new catalyst and exchange heat with it. The new catalyst and the original regenerated catalyst further exchange heat through the inner cylinder wall. By having a portion of the original regenerated catalyst enter the catalyst replacement device to exchange heat with the new catalyst, it enters the regenerator to mix with the original regenerated catalyst for the next cycle. The method of this invention can recover heat from the hot catalyst, increase the temperature of the new catalyst, reduce thermal balance fluctuations within the regenerator, achieve rapid catalyst replacement, and improve the efficiency of flexible product structure adjustment.

[0082] Specifically, the process of the present invention includes the following steps:

[0083] (1) The catalyst from the regenerator enters the reactor from the bottom of the fluidized bed reactor.

[0084] (2) After the fluidizing medium passes through the distribution plate, it mixes with the catalyst from the regenerator. The catalyst flows upward under the action of the fluidizing medium.

[0085] (3) After the feed oil is preheated, it enters the fluidized bed reactor through the nozzle and mixes with the catalyst. Under the action of the fluidized medium, the feed oil and the catalyst flow upward into the reactor to carry out catalytic cracking reaction.

[0086] (4) The reaction product oil and gas and the catalyst are separated at the top of the fluidized bed reactor by a cyclone separator. The separated product oil and gas enter the fractionation unit, and the catalyst separated by the cyclone separator enters the stripper for stripping.

[0087] (5) After the catalyst is stripped, it enters the regenerator through the regeneration slide valve to burn coke. The flue gas generated by burning coke is separated by the cyclone separator and discharged. The regenerated catalyst enters the fluidized bed reactor through the regeneration slide valve for the next cycle.

[0088] (6) When switching operating modes, part of the original regenerated catalyst enters the outer cylinder of the catalyst replacement device for fluidization. Hot water flows into the heat exchange coil to generate superheated steam. The superheated steam enters the inner cylinder as a fluidization medium to fluidize the new catalyst and exchange heat with the catalyst. The new catalyst and the original regenerated catalyst exchange heat further through the inner cylinder wall. After the heat exchange is completed, the new catalyst quickly enters the regenerator to mix with the regenerated catalyst for the next cycle.

[0089] In one embodiment, the operating conditions of the reactor are:

[0090] The reaction temperature is 500-800℃;

[0091] The reaction pressure is 0.1-2.0 MPa;

[0092] The agent-to-oil ratio is 5-40;

[0093] The dwell time is 1.0-15.0 seconds.

[0094] In one embodiment, the outer cylinder of the catalyst heat exchanger is a fluidized bed with a linear velocity of 0.1-2 m / s; and / or

[0095] The fluidizing medium for the regenerated catalyst is selected from one or more of air, dry gas, and water vapor.

[0096] In one embodiment, the heat exchange medium generates superheated steam after heat exchange through the heat exchange coil. The superheated steam enters the inner cylinder through the catalyst replacement fluidizing medium pipeline for fluidizing and replacing the catalyst and for heat exchange.

[0097] Preferably, the heat exchange medium is water at 0-100°C;

[0098] More preferably, the inlet flow velocity of the heat exchange medium is 1-10 m / s.

[0099] In one embodiment, the linear velocity of the catalyst being replaced in the inner cylinder of the catalyst heat exchanger is 0.1-2 m / s; and / or

[0100] The replacement catalyst is heated to 300-500℃ and then enters the regenerator.

[0101] In one embodiment, the regeneration temperature in the regenerator is 550-850°C; and / or

[0102] The regeneration medium is one or more of air and pure oxygen.

[0103] In one embodiment, the feedstock oil and gas is selected from one or more of heavy distillate oil, gasoline, and diesel.

[0104] Preferably, the raw materials are preheated before entering the reactor, and the preheating temperature is preferably 100-300℃.

[0105] like Figure 1 As shown, the catalyst enters the fluidized bed reactor 5 through the regeneration slide valve 3. After being fluidized by the gas distribution plate 2 in the fluidizing medium 1, it enters the bottom of the fluidized bed reactor 5. The fluidizing medium carries the catalyst upward. The feed oil, after preheating, enters the bottom of the fluidized bed reactor 5 through the oil inlet nozzle 4 and mixes with the catalyst. The feed oil gas and catalyst flow upward in parallel into the reaction section 5 for catalytic cracking reaction to obtain product oil gas and the spent catalyst. The reaction product oil gas and spent catalyst are separated at the top of the reactor by the cyclone separator 6. The separated product oil gas is discharged from the fluidized bed reactor 5 through the product oil gas discharge pipeline 8. The product oil gas discharge pipeline 8 can be connected to further oil gas treatment equipment, such as entering the fractionation unit. The spent catalyst separated by the cyclone separator 6 enters the stripper 7 and is stripped by the stripping medium 9. After stripping, the spent catalyst enters the regenerator 11 through the spent catalyst slide valve 10, where it undergoes coking regeneration under the action of the regeneration medium 14. It is then separated and settled in the regenerator cyclone separator 12. The generated flue gas is separated again by the regenerator cyclone separator 12 and discharged from the flue gas outlet pipeline 13. The regenerated hot catalyst enters the outer cylinder 17 of the catalyst heat exchanger through the hot regenerator displacement slide valve 16. Under the action of the regenerated catalyst fluidizing medium 25, the hot catalyst flows upward and exchanges heat with the heat exchange medium in the heat exchange coil 23. The heat exchange medium in the heat exchange coil enters through the heat exchange medium inlet 21, undergoes a phase change after heat exchange, and generates superheated steam, which is then drawn out from the heat exchange medium outlet 22. In normal operation mode, the cooled regenerator after heat exchange returns to the regenerator through the cold regenerator displacement slide valve 15 and settles to the bottom of the regenerator before entering the reactor through the regeneration slide valve 3 for the next cycle.

[0106] When the operation mode is switched to catalyst replacement mode, part of the hot regenerated catalyst enters the outer cylinder 17 of the catalyst replacement device through the hot regenerator replacement slide valve 16. The hot catalyst is fluidized through the regenerated catalyst fluidizing medium 25. The heat exchange medium enters the heat exchange coil 23 from the heat exchange medium inlet 21 to exchange heat with the hot regenerated catalyst. The generated superheated steam flows out through the heat exchange medium outlet 22. Part of the superheated steam is fluidized through the replacement catalyst fluidizing medium inlet valve 24. The new replacement catalyst entering from the replacement catalyst addition line 19 is carried into the inner cylinder 18 of the catalyst replacement device. After reaching a certain temperature (300-500℃), it enters the regenerator 11 through the replacement catalyst outlet line 20 and settles to the bottom of the regenerator. It then enters the reactor through the regeneration slide valve 3 for recycling. The original regenerated catalyst after heat exchange can be discharged through the catalyst unloading line 26 to avoid disturbing the regenerator.

[0107] The reaction conditions in the fluidized bed reactor are as follows: reaction temperature 500-800℃, reaction pressure 0.1-2.0MPa, agent-to-oil ratio 5-20, and residence time 1.0-15.0 seconds.

[0108] The regeneration conditions inside the regenerator are: regeneration temperature of 550-850℃ and regeneration medium of air.

[0109] The properties of the hydrogenated catalytic converters used in the examples are shown in Table 1.

[0110] The catalysts used in the examples are commercial NTO catalysts and CGP catalysts.

[0111] Example 1

[0112] This embodiment follows Figure 1 The equipment and process were tested to achieve a multi-product chemical feedstock operation mode. The reaction was carried out in a small riser reactor, using the hydrotreated diesel oil in Table 1 as feedstock and NTO catalyst.

[0113] This embodiment uses a regeneration device with a volume of 1.2m³. 3 The total catalyst loading is 10 kg. The reaction and regeneration process conditions are as follows: hydrogenation catalyst preheating temperature is 200℃, reaction outlet temperature is 530℃, reaction pressure is 0.2 MPa, residence time is 1.5 s, catalyst-to-oil ratio is 8, regenerator outlet temperature is 700℃, and the regenerator medium is air.

[0114] The catalyst heat exchanger has an outer cylinder height-to-diameter ratio of 10, an outer cylinder diameter of 0.5m, and a linear velocity of 0.5m / s. The fluidizing medium for the regenerated catalyst is air. The bottom heat exchange coil has a diameter of 0.02 times the outer cylinder diameter, and the heat exchange medium is 100℃ hot water with an inlet velocity of 3m / s. The inner cylinder diameter is 0.3 times the outer cylinder diameter, with a height-to-diameter ratio of 10, and there are 4 tubes (e.g., ...). Figure 2(a) shows a schematic diagram. The linear velocity inside the tube is 1 m / s. The new replacement catalyst is heated to 300°C and then enters the regenerator.

[0115] The NTO catalyst enters the fluidized bed reactor 5 via the regeneration slide valve 3. The fluidizing medium 1, after being fluidized by the gas distribution plate 2, enters the bottom of the fluidized bed reactor 5, carrying the catalyst upwards. The feedstock oil, preheated to 200°C, enters the bottom of the fluidized bed reactor 5 through the inlet nozzle 4 and mixes with the catalyst. The feedstock oil and catalyst flow upwards in parallel into the reaction section for catalytic cracking. The reaction product oil and catalyst are separated at the top of the reactor by the cyclone separator 6. The separated product oil and gas enter the fractionation unit through the product oil and gas discharge pipeline 8. The catalyst separated by the cyclone separator 6 enters the stripper 7 and is stripped by the stripping medium 9. The stripped catalyst enters the regenerator 11 through the regeneration slide valve 10 for coke burn regeneration. It is then separated and settled in the regenerator cyclone separator 12. The generated flue gas is separated by the regenerator cyclone separator 12 and discharged from the flue gas outlet pipeline 13. The regenerated hot catalyst enters the outer cylinder 17 of the catalyst heat exchanger through the hot regenerator displacement valve 16. Under the action of the regenerated catalyst fluidizing medium 25, the hot catalyst flows upward and exchanges heat with the hot water in the heat exchange coil 23. After heat exchange, the cold regenerator returns to the regenerator 11 through the cold regenerator displacement valve 15 and settles to the bottom of the regenerator before entering the reactor through the regeneration valve 3 for the next cycle.

[0116] When switching operating modes, part of the original regenerated NTO catalyst enters the outer cylinder 17 of the catalyst replacement device through the hot regenerator replacement slide valve 16. It is fluidized by the regenerated catalyst fluidizing medium 25. Hot water enters the heat exchange coil 23 from the heat exchange medium inlet 21 to exchange heat with the hot NTO catalyst. The generated superheated steam flows out through the heat exchange medium outlet 22. Part of the superheated steam is fluidized through the replacement catalyst fluidizing medium inlet valve 24, carrying the new replacement catalyst CGP catalyst entering from the replacement catalyst addition line 19 into the inner cylinder 18 of the catalyst replacement device. After reaching a certain temperature, it enters the regenerator 11 through the replacement catalyst outlet line 20 for cyclic reaction. The original NTO regenerated catalyst can be discharged through the catalyst unloading line 26 to avoid disturbing the thermal balance within the regenerator 11.

[0117] Under these conditions, after stable operation, when the replacement rate of the new catalyst reaches 50%, the replacement time is measured to be 5 hours.

[0118] Example 2

[0119] This embodiment follows Figure 1 The equipment and process were tested to achieve a multi-product chemical feedstock operation mode. The reaction was carried out in a small riser reactor, using the hydrotreated diesel oil in Table 1 as feedstock and NTO catalyst.

[0120] This embodiment uses a regeneration device with a volume of 1.2m³. 3 The catalyst loading is 10 kg.

[0121] The process conditions for reaction and regeneration are as follows: the preheating temperature of the hydrogenation catalytic converter is 200℃, the reaction outlet temperature is 530℃, the reaction pressure is 0.2MPa, the residence time is 1.5s, the catalyst-to-oil ratio is 8, the regenerator outlet temperature is 700℃, and the regenerator medium is air.

[0122] The catalyst heat exchanger has an outer cylinder height-to-diameter ratio of 10, an outer cylinder diameter of 0.5m, and a linear velocity of 0.5m / s. The fluidizing medium for the regenerated catalyst is air. The bottom heat exchange coil has a diameter of 0.02 times the outer cylinder diameter, and the heat exchange medium is 100℃ hot water with an inlet velocity of 3m / s. The inner cylinder diameter is 0.2 times the outer cylinder diameter, with a height-to-diameter ratio of 10, and there are 8 tubes (e.g., ...). Figure 2 (b) Schematic diagram), the linear velocity inside the tube is 1 m / s, and the new replacement catalyst is heated to 300°C and then enters the regenerator.

[0123] The NTO catalyst enters the fluidized bed reactor 5 via the regeneration slide valve 3. The fluidizing medium 1, after being fluidized by the gas distribution plate 2, enters the bottom of the fluidized bed reactor 5, carrying the catalyst upwards. The feedstock oil, after preheating, enters the bottom of the fluidized bed reactor 5 through the inlet nozzle 4 and mixes with the catalyst. The feedstock oil and catalyst flow upwards in parallel into the reaction section for catalytic cracking. The reaction product oil and catalyst are separated at the top of the reactor by a cyclone separator 6. The separated product oil and gas enter the fractionation unit through the product oil and gas discharge pipeline 8. The catalyst separated by the cyclone separator 6 enters the stripper 7 and is stripped by the stripping medium 9. The stripped catalyst enters the regenerator 11 through the regeneration slide valve 10 for coke burn regeneration. It is then separated and settled in the regenerator cyclone separator 12. The generated flue gas is separated by the regenerator cyclone separator 12 and discharged from the flue gas outlet pipeline 13. The regenerated hot catalyst enters the outer cylinder 17 of the catalyst heat exchanger through the hot regenerator displacement valve 16. Under the action of the regenerated catalyst fluidizing medium 25, the hot catalyst flows upward and exchanges heat with the hot water in the heat exchange coil 23. After heat exchange, the cold regenerator returns to the regenerator 11 through the cold regenerator displacement valve 15 and settles to the bottom of the regenerator before entering the reactor through the regeneration valve 3 for the next cycle.

[0124] When switching operating modes, a portion of the original regenerated NTO catalyst enters the outer cylinder 17 of the catalyst replacement device via the hot regenerator replacement valve 16. It is fluidized by the regenerated catalyst fluidizing medium 25. Hot water enters the heat exchange coil 23 from the heat exchange medium inlet 21 to exchange heat with the hot NTO catalyst. The generated superheated steam flows out through the heat exchange medium outlet 22. Part of the superheated steam is fluidized by the replacement catalyst fluidizing medium inlet valve 24, carrying the new replacement catalyst CGP catalyst entering from the replacement catalyst addition line 19 into the inner cylinder 18 of the catalyst replacement device. After reaching a certain temperature, it enters the regenerator 11 via the replacement catalyst outlet line 20 for cyclic reaction. The original NTO regenerated catalyst can be discharged via the catalyst discharge line, avoiding disturbance to the thermal balance within the regenerator 11.

[0125] Under these conditions, after stable operation, when the replacement rate of the new catalyst reaches 50%, the replacement time is measured to be 4 hours.

[0126] Comparative Example 1

[0127] This comparative example uses a conventional upflow external heat exchanger and the reaction is carried out in a small riser reactor. NTO balancer is used, and the feed oil is the same as in Example 1.

[0128] The comparative example uses a regeneration device with a volume of 1.2m³. 3 The catalyst loading is 10 kg.

[0129] The reaction and regeneration process conditions are as follows: the preheating temperature of the hydrocatalytic diesel generator is 200℃, the reaction outlet temperature is 530℃, the catalyst-to-oil ratio is 8, the regenerator outlet temperature is 700℃, and the regenerator medium is air. Catalyst replacement is performed using conventional methods. Part of the NTO catalyst is unloaded from the regenerator. After unloading, once the temperature stabilizes, a portion of the CGP catalyst is added back to the regenerator. The addition and unloading processes should not be too rapid to ensure thermal balance during the reaction and stable operation of the subsequent fractionation process, avoiding drastic fluctuations in the unit. Catalyst replacement is carried out gradually through small-scale unloading and addition.

[0130] Under these conditions, after stable operation, when the replacement rate of the new catalyst reached 50%, the replacement time was measured to be 30 hours. This replacement time is 6 times and 7.5 times that of Examples 1 and 2, respectively, indicating a longer replacement time.

[0131] Using the apparatus of Comparative Example 1, Example 1, and Example 2, the catalyst replacement ratio and product distribution after simultaneous replacement for 4 hours are shown in Table 2. As can be seen from the table, the replacement methods used in Example 1 and Example 2 have a faster replacement rate, enabling quicker adjustment of the product structure, and are particularly suitable for flexible adjustments in large-scale plants.

[0132] Table 1

[0133]

[0134] Table 2

[0135]

[0136]

[0137] *Trienes refer to ethylene, propylene, and butadiene. The triene yield refers to the yield of trienes obtained after further separation of the product.

[0138] **BTX refers to light aromatic hydrocarbons, namely a mixture of benzene, toluene, and xylene. The BTX yield refers to the yield of light aromatic hydrocarbons (BTX) obtained after further separation of the product.

[0139] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A catalyst heat exchange and displacement device, characterized in that, The catalyst heat exchange and replacement device has an outer cylinder, and a heat exchange coil is housed inside the outer cylinder. The heat exchange coil is provided with a heat exchange medium inlet and a heat exchange medium outlet, which are located outside the outer cylinder. The heat exchange coil is connected to the fluidized medium pipeline of the displacement catalyst. The fluidized medium pipeline of the displacement catalyst is equipped with a fluidized medium inlet valve of the displacement catalyst. The fluidized medium inlet valve of the displacement catalyst is located outside the outer cylinder and close to the outlet side of the heat exchange medium. The outer cylinder is provided with one or more inner cylinders. The bottom of the inner cylinder is provided with a displacement catalyst inlet, which is connected to the displacement catalyst fluidizing medium pipeline. The top of the inner cylinder is provided with a displacement catalyst outlet, which is connected to the displacement catalyst discharge pipeline. The heat exchange coil is located below the one or more inner cylinders. The fluidized medium pipeline for the displacement catalyst is also provided with a displacement catalyst inlet, which is connected to the displacement catalyst addition pipeline and is located downstream of the fluidized steam inlet valve. The outer cylinder is also equipped with a regenerated catalyst fluidized medium inlet, a catalyst unloading pipeline, a regenerated catalyst heat exchange inlet, and a regenerated catalyst heat exchange outlet. The regenerated catalyst fluidized medium inlet, catalyst unloading pipeline, and regenerated catalyst heat exchanger are located at the lower part of the external heat exchanger, and are all located below the heat exchange coil.

2. The catalyst heat exchange and displacement device according to claim 1, characterized in that, The outer cylinder of the catalyst heat exchanger is cylindrical with a height-to-diameter ratio of 0.1-20; and / or The diameter of the heat exchange coil is 0.01-0.1 times the outer cylinder diameter.

3. The catalyst heat exchange and displacement device according to claim 1, characterized in that, The inner cylinder has a diameter of 0.05-0.4 times that of the outer cylinder, and a height-to-diameter ratio of 0.1-20. Preferably, the number of inner cylinders is 4-10.

4. A catalytic cracking reaction system, comprising: The reactor is equipped with a reaction oil and gas inlet, a reactor fluidized medium inlet, a catalyst inlet, an oil and gas separation device, a product oil and gas outlet, and a catalyst outlet. The oil and gas separation device includes a cyclone separator and a stripper. A regenerator is used to regenerate the catalyst to be generated. It is equipped with a regenerating inclined tube, a regeneration medium inlet, a flue gas outlet, a regeneration catalyst heat exchange outlet, a regeneration catalyst heat exchange return inlet, a replacement catalyst inlet, and a regeneration inclined tube. The regenerating inclined tube is connected to the regenerating catalyst outlet of the reactor, and the regeneration inclined tube is connected to the catalyst inlet of the reactor. and The catalyst heat exchange and replacement device according to any one of claims 1 to 3 is used for heat exchange and catalyst replacement of the regenerated catalyst, wherein the catalyst replacement outlet pipeline of the catalyst heat exchange and replacement device is connected to the catalyst replacement inlet of the regenerator, the regenerated catalyst heat exchange inlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange outlet of the regenerated catalyst, and the regenerated catalyst heat exchange outlet of the catalyst heat exchange and replacement device is connected to the regenerated catalyst heat exchange return inlet of the regenerator.

5. The catalytic cracking reaction system according to claim 4, characterized in that, The reactor is a fluidized bed reactor; Preferably, the fluidized bed reactor is selected from one or more of the following: riser reactor, fast bed reactor, turbulent bed reactor, and downflowing bed reactor.

6. A catalytic cracking method, said catalytic cracking method using the catalytic cracking reaction system of claim 4 or 5, comprising: Fluidized medium enters the reactor from the bottom, and catalyst from the regenerator enters the reactor. The feedstock oil and gas and the catalyst react in the reactor. The resulting oil and gas products are separated from the spent catalyst at the end of the reactor. The separated oil and gas products are led out of the reactor. The spent catalyst is stripped and then enters the regenerator for regeneration. The regenerated catalyst enters the outer cylinder of the catalyst heat exchange replacement device to exchange heat with the heat exchange medium in the heat exchange coil. Under the action of the fluidized medium of the regenerated catalyst, it returns to the regenerator through the heat exchange outlet of the regenerated catalyst and then enters the reactor through the regeneration inclined tube set at the bottom of the regenerator for recycling reaction. During catalyst replacement, the regenerated catalyst enters the outer cylinder of the catalyst heat exchanger and replacement device for heat exchange. Then, 10%-80% of the catalyst is discharged through the catalyst unloading pipeline of the catalyst heat exchanger and replacement device. The replacement catalyst enters the inner cylinder of the catalyst heat exchanger and replacement device through the replacement catalyst inlet under the action of the replacement catalyst fluidizing medium and completes heat exchange. It then enters the regenerator through the replacement catalyst outlet pipeline to mix with the regenerated catalyst for a cyclic reaction.

7. The method according to claim 6, characterized in that, The operating conditions of the reactor are as follows: The reaction temperature is 500-800℃; The reaction pressure is 0.1-2.0 MPa; The agent-to-oil ratio is 5-40; The dwell time is 1.0-15.0 seconds.

8. The method according to claim 6, characterized in that, The outer cylinder of the catalyst heat exchanger is a fluidized bed with a linear velocity of 0.1-2 m / s; and / or The fluidizing medium for the regenerated catalyst is selected from one or more of air, dry gas, and water vapor.

9. The method according to claim 6, characterized in that, After the heat exchange medium is heated by the heat exchange coil, it generates superheated steam. The superheated steam enters the inner cylinder through the fluidized medium pipeline for replacing the catalyst, and is used to fluidize and replace the catalyst and perform heat exchange. Preferably, the heat exchange medium is water at 0-100°C; More preferably, the inlet flow velocity of the heat exchange medium is 1-10 m / s.

10. The method according to claim 6, characterized in that, The linear velocity of the catalyst being replaced in the inner cylinder of the catalyst heat exchanger is 0.1-2 m / s; and / or The replacement catalyst is heated to 300-500℃ and then enters the regenerator.

11. The method according to claim 6, characterized in that, The regeneration temperature in the regenerator is 550-850℃; and / or The regeneration medium is one or more of air and pure oxygen.

12. The method according to claim 6, characterized in that, The feedstock oil and gas are selected from one or more of heavy distillate oil, gasoline, and diesel. Preferably, the raw materials are preheated before entering the reactor, and the preheating temperature is preferably 100-300℃.

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