Method and equipment for dechlorination bed catalyst inactivation of propane dehydrogenation device

Abstract

The invention discloses a method and equipment for inactivating a catalyst of a dechlorination bed of a propane dehydrogenation device, and belongs to the technical field of petrochemical engineering. Comprising the following steps: S1, regeneration operation: carrying out hot nitrogen steam stripping on a dechlorinating agent in a dechlorinating bed through low-pressure nitrogen, and removing aromatic solvent oil and residual impurities adsorbed by the dechlorinating agent; s2, passivation operation: injecting low-pressure steam into the dechlorinating bed in stages, and enabling the low-pressure steam and nitrogen to generate a passivation reaction until the dechlorinating agent is completely inactivated under the synergistic effect of the low-pressure steam and the nitrogen; and S3, unloading the dechlorinating agent, namely safely unloading the dechlorinating agent after inactivation from the dechlorinating bed, and replacing the dechlorinating agent with a new dechlorinating agent. Aromatic solvent oil adsorbed by the dechlorinating agent is removed through hot nitrogen steam stripping, and then the dechlorinating agent is ensured to be completely inactivated before being unloaded through staged steam passivation, so that the problem that in the prior art, solvent oil overflows in the fire extinguishing process of the dechlorinating agent in a water injection mode during agent unloading, and the fire extinguishing effect is poor is solved. The surrounding environment is polluted; and a downstream water treatment system is impacted.

Description

Technical Field

[0001] The present invention belongs to the technical field of petrochemical industry, and particularly relates to a method and equipment for deactivating a dechlorination bed catalyst in a propane dehydrogenation unit. Background Art

[0002] The existing propane dehydrogenation unit is designed with an annual production scale of 511,700 tons of propylene and adopts UOP Oleflex process technology. The raw materials of this unit are refinery propane and propane from an ethylene unit. The reaction products enter the product gas contact cooling tower from the side, are cooled to 43°C by countercurrent contact with a circulating solvent (solvent oil rich in aromatics), and then are further processed by a product gas compressor. Finally, the product gas undergoes a series of treatment steps and then enters a dechlorination processor for dechlorination treatment.

[0003] Due to incomplete gas-liquid separation, part of the solvent oil is entrained in the gas-phase product output from the reactor. After the solvent oil enters the dechlorination bed, it is adsorbed by the dechlorination agent. The product chlorine comes from the chlorine gas injected during the re-dispersion of platinum in the chlorination zone of the catalyst, which is used for the oxychlorination reaction with the platinum metal on the catalyst and the chloride ions carried by the fresh feed. Since chlorine is a poison to the downstream SHP catalyst and HCl can cause equipment corrosion, it is necessary to remove the chlorides.

[0004] The current dechlorination process uses a dechlorination agent to dechlorinate the gas-phase product output from the reactor, but this process has the following problems:

[0005] 1. Safety hazards and environmental pollution:

[0006] The dechlorination agent in the dechlorination bed will adsorb a large amount of aromatic solvent oil during use. Since these dechlorination agents will react violently with air and release a large amount of heat after contacting with air, the temperature of the dechlorination agent continues to rise, and even spontaneous combustion may occur.

[0007] During the process of unloading the old dechlorination agent, water injection is usually used to extinguish the fire, but this will cause the solvent oil to overflow, pollute the on-site environment, and impact the downstream water treatment system.

[0008] 2. Operational complexity and time consumption:

[0009] Each replacement of the dechlorination agent takes 10 - 15 days. During this period, the unit needs to shut down or operate at reduced production, seriously affecting the continuity of production and economic benefits.

[0010] Condition limitations make it impossible to dispose of the oil-containing dechlorination agent in a timely manner, further prolonging the entire treatment cycle. Summary of the Invention

[0011] The present invention addresses the above-mentioned problems existing in the prior art, and provides a method and equipment for inactivating the catalyst in the dechlorination bed of a propane dehydrogenation unit, which can remove the aromatic solvent oil in the dechlorination agent and ensure the continuity of production.

[0012] The present invention can be achieved through the following technical solutions:

[0013] A method for inactivating the catalyst in the dechlorination bed of a propane dehydrogenation unit, comprising the following steps:

[0014] S1. Regeneration operation: Thermally strip the dechlorination agent in the dechlorination bed with low-pressure nitrogen to remove the aromatic solvent oil and residual impurities adsorbed by the dechlorination agent.

[0015] S2. Passivation operation: Inject low-pressure steam into the dechlorination bed in stages, and cooperate with nitrogen to cause the dechlorination agent to undergo a passivation reaction until it is completely inactivated.

[0016] S3. Agent unloading operation: Safely unload the inactivated dechlorination agent from the dechlorination bed and replace it with a new dechlorination agent.

[0017] As a further improvement of the present invention, in step S1, the flow rate of the regeneration nitrogen is increased in stages, with the initial flow rate increase ≤ 500 kg / h, the flow rate increase per hour ≤ 2000 kg / h, and finally a nitrogen flow rate of 10000 - 20000 kg / h is established.

[0018] As a further improvement of the present invention, in step S1, it further includes:

[0019] S11. After the nitrogen flow rate reaches 10000 kg / h, start the electric heater to heat the nitrogen, with the heating rate ≯ 50 °C / h, and raise the temperature of the dechlorination bed to 210 - 230 °C and keep it constant for 3 - 5 h.

[0020] As a further improvement of the present invention, after step S11, it further includes:

[0021] S12. After the temperature of the dechlorination bed reaches the constant temperature, lower its temperature to 170 - 190 °C to prepare for step S2.

[0022] As a further improvement of the present invention, step S2 includes staged passivation:

[0023] S21. First stage: The steam flow rate is 500 - 1000 kg / h, the steam accounts for 5% wt of the nitrogen mass, and the passivation time is 24 - 48 hours.

[0024] S22. Second stage: The steam flow rate is increased to 1000 - 2000 kg / h, the steam accounts for 10% wt of the nitrogen mass, and the passivation time is 24 - 48 hours.

[0025] S23. Third stage: The steam flow rate is increased to 2000 - 4000 kg / h, the steam accounts for 20% wt of the nitrogen mass, and the passivation time is 24 - 48 hours.

[0026] As a further improvement of the present invention, after step S23, it further includes:

[0027] S24. When the temperature at the outlet of the dechlorination bed drops to 140 - 160 °C, the steam flow rate is reduced to 1000 - 2000 kg / h, and the steam accounts for 10% wt of the nitrogen mass.

[0028] As a further improvement of the present invention, after step S24, it further includes:

[0029] S25. When the temperature at the outlet of the dechlorination bed drops below 70 °C, stop injecting steam, and the passivation is completed.

[0030] As a further improvement of the present invention, after step S25, it further includes:

[0031] S26. Continue to introduce nitrogen until the temperature of the dechlorination bed drops below 40 °C, then stop nitrogen, and prepare for catalyst unloading.

[0032] There is also provided a device for inactivating the catalyst of the dechlorination bed in a propane dehydrogenation unit, which adopts the above - mentioned method for inactivating the catalyst of the dechlorination bed in a propane dehydrogenation unit, and includes:

[0033] Product compressor;

[0034] At least two dechlorination beds arranged in parallel, which are respectively connected to the product compressor;

[0035] Regeneration and passivation system, including a low - pressure nitrogen source, a low - pressure steam source and an electric heater;

[0036] Product dryer, which is connected to the product compressor through a dechlorination bed bypass;

[0037] Among them, the nitrogen and steam of the regeneration and passivation system are introduced from the bottom of the dechlorination bed, and the top is connected to the hot flare network through a regeneration discharge line. The product gas output by the product compressor is introduced from the top of the dechlorination bed.

[0038] As a further improvement of the present invention, the regeneration discharge line is provided with a flare condensate tank for separating condensate and gas phase. The condensate is pumped to the light dirty oil tank after water separation through a water - separating package, and the gas phase is discharged into the hot flare network.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. First, remove the aromatic solvent oil adsorbed by the dechlorination agent through hot nitrogen stripping, and then perform staged steam passivation to ensure that the dechlorination agent completely loses its activity before unloading, solving the problems in the prior art that during the unloading of the agent, when extinguishing the fire of the dechlorination agent by injecting water, there is an overflow of solvent oil, resulting in environmental pollution around and impacting the downstream water treatment system;

[0041] 2. Before performing the passivation operation, keep purging with nitrogen until the gas exiting to the hot flare network contains a total of less than 10% of the lower explosive limit (LEL) of flammable substances, ensuring that the content of flammable substances in the gas reaches the safety standard;

[0042] 3. During the regeneration operation, by gradually increasing the nitrogen flow rate, ensure that the aromatic solvent oil and impurities in the dechlorination agent are fully purged, improving the regeneration efficiency and effect. Among them, the heating rate of the heater for nitrogen should not exceed 50 °C / h to prevent potential safety hazards or damage to equipment caused by too fast heating. Raising the temperature of the dechlorination bed 100 to 210 - 230 °C and maintaining this temperature for 3 - 5 hours helps to thoroughly remove the aromatic solvent oil and other impurities in the dechlorination agent, ensuring good regeneration operation effect;

[0043] 4. During the passivation operation, by introducing low-pressure steam in stages, not only improves the safety and passivation effect of the operation, ensures that the dechlorination agent completely loses its activity before unloading, provides guarantee for subsequent safe unloading and replacement of the new dechlorination agent, but also reduces equipment stress, enhances process flexibility and controllability, and at the same time has energy-saving and economic benefits;

[0044] 5. At least two dechlorination beds are in standby for each other. Thus, when replacing the dechlorination agent in one of the dechlorination beds, the other dechlorination beds can continue to operate, and the entire system can still maintain high-load operation, ensuring the continuity of production, and also ensuring that the desiccant in the product dryer can reach the designed service life. Description of the Drawings

[0045] Figure 1 is the schematic diagram of the method for inactivating the catalyst in the dechlorination bed of the propane dehydrogenation device of the present invention.

[0046] In the figure, 100, dechlorination bed; 110, product compressor; 120, outlet buffer tank; 130, electric heater; 140, product dryer; 150, dechlorination bed bypass; 160, hot flare network; 170, regeneration discharge line; 180, safety valve. Detailed Embodiments

[0047] The following are specific embodiments of the present invention in combination with the drawings, and the technical methods of the present invention are further described, but the present invention is not limited to these embodiments.

[0048] As Figure 1As shown in the figure, the present invention provides a method for inactivating the dechlorination bed catalyst of a propane dehydrogenation device, comprising the following steps:

[0049] S1. Regeneration operation: Thermally nitrogen strip the dechlorination agent in the dechlorination bed 100 with low-pressure nitrogen to remove the aromatic solvent oil and residual impurities adsorbed by the dechlorination agent;

[0050] S2. Passivation operation: Inject low-pressure steam into the dechlorination bed 100 in stages, and cooperate with nitrogen to cause the dechlorination agent to undergo a passivation reaction until it is completely inactivated;

[0051] S3. Agent unloading operation: Safely unload the inactivated dechlorination agent from the dechlorination bed 100 and replace it with a new dechlorination agent.

[0052] It should be noted that after the dechlorination agent reaches its normal service life, trace impurity compounds may concentrate on the used dechlorination agent. These impurities may be toxic or flammable. Directly exposing the dechlorination agent to the ambient air may release toxic substances. These residual harmful substances mainly come from bed breakthrough, dechlorination agent caking, carbon deposition reaction, entrained liquid, and incomplete regeneration. If the remaining substances are reactants such as olefins or other hydrocarbons, it may lead to fire and / or release of toxic substances;

[0053] Therefore, before unloading the dechlorination agent, it is necessary to let the dechlorination agent drain the substances it adsorbs. This process is step S1, and to make the dechlorination agent no longer have the adsorption effect, this process is step S2.

[0054] In view of the above problems, in this embodiment, first, the aromatic solvent oil adsorbed by the dechlorination agent is removed by thermal nitrogen stripping, and then the dechlorination agent is completely inactivated before unloading through staged steam passivation, solving the problems in the prior art that during the agent unloading process, when extinguishing the fire of the dechlorination agent by injecting water, there is solvent oil overflow, resulting in environmental pollution around and impacting the downstream water treatment system.

[0055] In addition, before the passivation operation, nitrogen purging needs to be maintained until the gas exiting to the hot torch network 160 contains a total of less than 10% of the lower explosive limit (LEL) of flammable substances, ensuring that the content of flammable substances in the gas reaches the safety standard. The lower explosive limit content of various common flammable substances in the air is shown in Table 1.

[0056] Flammable substances Volume content in air % Methane 5.0 Ethane 2.9 Propane 2.1 n-Butane 1.6 Hydrogen 4.0 Benzene 1.4

[0057] Table 1

[0058] Specifically, the following is a detailed description of step S1:

[0059] Preferably, in step S1, the dechlorination agent in the dechlorination bed 100 is thermally nitrogen stripped with low-pressure nitrogen to remove the aromatic solvent oil and residual impurities adsorbed by the dechlorination agent. To ensure safety and effectiveness, the nitrogen flow rate needs to be gradually increased in stages:

[0060] 1. Initial flow rate increase: At the beginning, the nitrogen flow rate should not exceed 500 kg / h to slowly introduce nitrogen and avoid system pressure fluctuations or instability caused by a sudden large amount of gas entering;

[0061] 2. Hourly flow rate increase: During the nitrogen introduction process, the maximum hourly flow rate increase should not exceed 2000 kg / h to ensure that nitrogen can uniformly penetrate through the entire 100 layers of the dechlorination bed and effectively displace and carry away the flammable gases therein;

[0062] 3. Final nitrogen flow rate: After gradual increase, a final nitrogen flow rate of 10000 - 20000 kg / h is established to ensure that all areas within the dechlorination bed 100 are fully purged.

[0063] By gradually increasing the nitrogen flow rate, it is ensured that the aromatic solvent oil and impurities in the dechlorination agent are fully purged, improving the regeneration efficiency and effect.

[0064] Furthermore, in step S1, it also includes:

[0065] S11. When the nitrogen flow rate reaches 10000 kg / h, start the electric heater 130 to heat up the nitrogen. In this step:

[0066] First of all, the heating rate of the electric heater 130 for nitrogen should not exceed 50 °C / h to prevent potential safety hazards or damage to equipment caused by too fast heating;

[0067] Secondly, raise the temperature of the dechlorination bed 100 to 210 - 230 °C and maintain this temperature for 3 - 5 hours. This process helps to thoroughly remove the aromatic solvent oil and other impurities in the dechlorination agent, ensuring good effect of the regeneration operation.

[0068] Furthermore, after step S11, it also includes:

[0069] S12. After the constant temperature of the dechlorination bed 100 ends, lower its temperature to 170 - 190 °C to prepare for the next passivation operation. This temperature range will neither be too high to generate excessive heat when steam is introduced nor too low to form saturated steam, resulting in condensate generation that affects the passivation effect.

[0070] Specifically, the following is the detailed description of step S2:

[0071] Preferably, step S2 includes staged passivation:

[0072] S21. The first stage: the steam flow rate is 500 - 1000 kg / h, the steam accounts for 5% wt of the nitrogen mass, and the passivation time is 24 - 48 hours;

[0073] In this initial stage, by introducing steam with a lower steam flow rate and a relatively small proportion, the passivation process can be gently started, ensuring that the dechlorination agent gradually loses its activity without triggering violent reactions or sudden temperature rises. This step helps to smoothly transition to a higher-intensity passivation operation.

[0074] S22. The second stage: the steam flow rate is increased to 1000 - 2000 kg / h, the steam accounts for 10% wt of the nitrogen mass, and the passivation time is 24 - 48 hours;

[0075] Based on the first stage, gradually increase the steam flow rate and proportion to further promote the passivation reaction of the dechlorination agent. The increase in the steam volume and proportion in this stage can accelerate the passivation process, but still remain within a controllable range to avoid potential safety hazards caused by excessive temperature rise or overreaction.

[0076] S23. The third stage: the steam flow rate is increased to 2000 - 4000 kg / h, the steam accounts for 20% wt of the nitrogen mass, and the passivation time is 24 - 48 hours;

[0077] In the final stage, significantly increase the steam flow rate and proportion to ensure that the dechlorination agent completely loses its activity. The high steam flow rate and proportion in this stage can ensure that all dechlorination agent particles are fully exposed to steam and undergo effective passivation reactions, ultimately achieving the purpose of complete inactivation.

[0078] By introducing low-pressure steam in stages for passivation operation, not only improves the safety and passivation effect of the operation, ensures that the dechlorination agent completely loses its activity before unloading, provides guarantee for subsequent safe unloading and replacement of new dechlorination agent, but also reduces equipment stress, enhances process flexibility and controllability, and at the same time has energy-saving and economic benefits.

[0079] Furthermore, after step S23, it also includes:

[0080] S24. When the outlet temperature of the dechlorination bed 100 drops to 140 - 160 °C, it indicates that the dechlorination agent has undergone sufficient high-temperature passivation treatment and begins to gradually cool down. At this time, reduce the steam flow rate to 1000 - 2000 kg / h, and the steam accounts for 10% wt of the nitrogen mass. Keep this lower steam flow rate and proportion for a period of time to ensure that the dechlorination agent is further passivated under mild conditions and stabilize its state, preventing potential problems caused by incomplete passivation due to rapid cooling or temperature fluctuations.

[0081] S25. When the outlet temperature of the dechlorination bed 100 drops below 70°C, it indicates that the dechlorination agent has reached a relatively stable low-temperature state. At this time, stop injecting steam, the passivation is completed, and the dechlorination agent has completely lost its activity.

[0082] S26. Continue to introduce nitrogen until the temperature of the dechlorination bed 100 drops below 40°C, then stop the nitrogen and prepare for discharging the agent. Nitrogen, as an inert gas, can help maintain an oxygen-free environment inside the dechlorination bed 100 and avoid any possible oxidation reaction. Until the temperature drops below 40°C, this temperature range is usually a safe operating temperature suitable for subsequent discharging operations.

[0083] By gradually reducing the steam flow rate and ratio, it is possible to avoid a sudden temperature drop caused by rapid cooling, and continue to maintain an appropriate steam flow rate and ratio during the temperature drop process, providing additional time for the passivation reaction to proceed fully and improving the passivation effect.

[0084] As Figure 1 shown, the present invention also provides a device for inactivating the catalyst of the dechlorination bed 100 in a propane dehydrogenation unit. Using the method for inactivating the catalyst of the dechlorination bed 100 in the above propane dehydrogenation unit, it includes:

[0085] A product compressor 110, which is used to output product gas. The outlet of the product compressor 110 is connected with an outlet buffer tank 120 to stabilize the pressure;

[0086] At least two dechlorination beds 100 arranged in parallel, which are respectively connected with the outlet buffer tank 120 of the product compressor 110;

[0087] A regeneration and passivation system, including a low-pressure nitrogen source, a low-pressure steam source and an electric heater 130. The low-pressure nitrogen source is used for thermally stripping the dechlorination agent in the dechlorination bed 100 to remove the adsorbed aromatic solvent oil and residual impurities. The low-pressure steam source is used to inject low-pressure steam into the dechlorination bed 100 in stages to cause the dechlorination agent to undergo a passivation reaction until it is completely inactivated. The electric heater 130 is used to heat nitrogen for better thermal nitrogen stripping;

[0088] A product dryer 140, which is connected with the product compressor 110 through a dechlorination bed bypass 150. The desiccant in the product dryer 140 has a certain ability to adsorb hydrogen chloride in the product gas and serves as a backup adsorption means for the dechlorination bed 100 and can be used when needed;

[0089] Among them, the nitrogen and steam of the regeneration and passivation system are introduced from the bottom of the dechlorination bed 100, and the top is connected with a hot flare network 160 through a regeneration discharge line 170. The product gas output by the product compressor 110 is introduced from the top of the dechlorination bed 100.

[0090] It is worth mentioning that at least two dechlorination beds 100 are in standby for each other. Thus, when replacing the dechlorination agent in one of the dechlorination beds 100, the other dechlorination beds 100 can continue to operate, and the entire system can still maintain high-load operation, ensuring the continuity of production. Therefore, the desiccant in the product dryer 140 can reach the designed service life.

[0091] Preferably, the regeneration discharge line 170 is provided with a flare condensate tank for separating condensate from the gas phase. The condensate is pumped to the light dirty oil tank for storage and subsequent treatment after water separation through a water separation package, and the gas phase is discharged into the hot flare network 160 for combustion treatment to ensure the safe discharge of waste gas.

[0092] Through effective gas-liquid separation and the treatment of condensate and gas phase, the risk of environmental pollution is reduced, meeting the high standards of modern chemical production.

[0093] In addition, a safety valve 180 is also provided on the bypass of the regeneration discharge line 170. During normal regeneration operation, the regeneration gas directly enters the hot flare network 160 through the regeneration discharge line 170 without passing through the safety valve 180. At this time, the safety valve 180 is in the put-into-use state. As a protection device, if the internal pressure of the system exceeds the set safety threshold, the safety valve 180 will automatically open to release the excessive pressure, ensuring that the system pressure returns to the safe range. The released gas will enter the hot flare network 160 through the outlet pipeline of the safety valve 180 and be burned in the flare system.

[0094] The technical means disclosed in the solution of the present invention are not limited to those disclosed in the above technical means, but also include technical solutions composed of any combination of the above technical features. The above is the specific implementation manner of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

[0095] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0096] In addition, in the present invention, descriptions such as "", "", and "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "", "" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0097] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0098] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation unit, characterized in that: The following steps are involved: S1. Regeneration operation: The dechlorinating agent in the dechlorinating bed is subjected to hot nitrogen stripping by low-pressure nitrogen to remove the aromatic solvent oil and residual impurities adsorbed by the dechlorinating agent; S2, passivation operation: inject low-pressure steam into the dechlorination bed in stages, and work together with nitrogen to make the dechlorination agent undergo a passivation reaction until it is completely inactivated; S3, agent unloading operation: safely unload the inactivated dechlorinating agent from the dechlorinating bed and replace it with a new dechlorinating agent.

2. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 1, characterized in that: In step S1, the flow rate of regenerated nitrogen is increased in stages, with an initial increase of ≤500kg / h, an increase of ≤2000kg / h per hour, and finally a nitrogen flow rate of 10000-20000kg / h.

3. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 1, characterized in that: In step S1, it also includes: S11. When the nitrogen flow rate reaches 10,000 kg / h, start the electric heater to heat the nitrogen at a heating rate of ≯50°C / h, raise the dechlorination bed temperature to 210-230°C and keep it constant for 3-5 hours.

4. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 2, characterized in that: After step S11, the method further includes: S12, after the dechlorination bed is kept at a constant temperature, the temperature is lowered to 170-190°C to prepare for step S2.

5. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 1, characterized in that: Step S2 includes a staged passivation: S21, first stage: steam flow rate is 500-1000kg / h, steam accounts for 5%wt of nitrogen mass, and passivation time is 24-48 hours; S22, second stage: steam flow rate is increased to 1000-2000 kg / h, steam accounts for 10%wt of nitrogen mass, and passivation time is 24-48 hours; S23, the third stage: the steam flow rate is increased to 2000-4000 kg / h, the steam accounts for 20%wt of the nitrogen mass, and the passivation time is 24-48 hours.

6. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 5, characterized in that: After step S23, the method further includes: S24. When the outlet temperature of the dechlorination bed drops to 140-160°C, the steam flow rate is reduced to 1000-2000 kg / h, and the steam accounts for 10%wt of the nitrogen mass.

7. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 6, characterized in that: After step S24, the method further includes: S25. When the outlet temperature of the dechlorination bed drops below 70°C, the steam injection is stopped and the passivation is completed.

8. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 7, characterized in that: After step S25, the method further includes: S26. Continue to introduce nitrogen until the temperature of the dechlorination bed drops below 40°C, stop nitrogen, and prepare to unload the agent.

9. A device for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device, using a method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device as claimed in any one of claims 1 to 8, characterized in that: include: Product compressor; At least two dechlorination beds are arranged in parallel and are respectively connected to the product compressor; A regeneration passivation system, including a low-pressure nitrogen source, a low-pressure steam source and an electric heater; a product dryer connected to the product compressor via a dechlorination bed bypass; The nitrogen and steam of the regeneration passivation system are introduced from the bottom of the dechlorination bed, and the top is connected to the hot torch pipe network through the regeneration discharge line. The product gas output by the product compressor is introduced from the top of the dechlorination bed.

10. The method for deactivating a catalyst in a dechlorination bed of a propane dehydrogenation device according to claim 9, characterized in that: The regeneration discharge line is provided with a flare condensate tank for separating the condensate from the gas phase. The condensate is pumped to the light dirty oil tank after cutting water through the water separation bag, and the gas phase is discharged into the hot flare pipe network.

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