Regeneration and cryogenic recovery process of high olefin dry dehydration bed

Abstract

The application discloses a kind of high olefin dry dehydration bed regeneration and cryogenic recovery process, belong to chemical separation and purification technical field, the process includes six steps of bed emptying, cold inert medium purging, heating desorption, staged cryogenic condensation recovery, bed cooling, pressure charging standby in sequence, maximum recovery free olefin by pre-emptying and purging step, inhibit high temperature polymerization, core uses staged cryogenic condensation recovery process to olefin component in desorption gas is condensed and recovered gradually, the loss problem of olefin material direct discharge flare in traditional process is solved, effectively inhibit olefin polymerization, by pre-cold inert medium purging step, remove the free olefin remaining in bed, cooperate with desorption temperature control and oxygen-free inert atmosphere throughout, avoid the occurrence of olefin polymerization reaction under high temperature condition, prevent the damage of green oil generation to adsorbent and equipment.

Description

Technical Field

[0001] This invention relates to the field of chemical separation and purification technology, specifically to a regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed, which is particularly suitable for the industrial regeneration operation of a fixed-bed adsorption drying unit for C4-C12 high-olefin materials. Background Technology

[0002] In petrochemical and fine chemical production processes, deep drying and dehydration of high-olefin materials is a core step in ensuring the stable operation of downstream processes such as polymerization, hydrogenation, and distillation. Industrially, fixed-bed adsorption drying processes are commonly used, employing molecular sieves, activated alumina, and other adsorbents for deep dehydration of high-olefin materials. After the adsorbent becomes saturated, a regeneration process is required to restore its adsorption performance. The stability and economic efficiency of this regeneration process directly determine the operating cost of the drying unit and the long-term operational capability of the equipment.

[0003] The existing technology has the following problems: 1. The existing high-olefin drying bed regeneration generally adopts nitrogen thermal regeneration process. The desorption gas containing high concentration of olefins generated in the heating and desorption stage is directly sent to the flare system for incineration. The annual loss of olefin material in a single unit can reach hundreds of tons, which not only causes serious waste of high-value raw materials and greatly increases the operating cost of the unit, but also significantly increases the emission load of the flare system and the pressure of environmental governance. 2. Existing regeneration processes have defects such as incomplete purging and replacement and insufficient precision in desorption temperature control. Residual olefins in the bed are prone to oligomerization reactions in a high-temperature and oxygen-free environment. The resulting green oil polymers will block the micropores of the adsorbent, causing an irreversible decrease in the adsorption capacity of the adsorbent, shortening the service life of the adsorbent, and increasing the pressure drop of the bed, which will affect the stability of the unit operation. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a regeneration and cryogenic recovery process for high olefin drying and dehydration beds to solve the problems of olefin material loss, easy polymerization of olefins, short adsorbent life and high environmental pressure in traditional regeneration processes, and to achieve stable regeneration of high olefin drying beds.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed includes six core steps: bed emptying, cold inert medium purging, heating and desorption, staged cryogenic condensation and recovery, bed cooling, and pressurization for standby. The details are as follows: Bed emptying: The adsorption-saturated high-olefin drying and dehydration bed is cut out of the production system, the feed and discharge valves are closed, the connecting valve between the bed and the emptying tank is opened, and the internal liquid high-olefin material is discharged into the emptying tank by the operating pressure of the bed itself until the pressure of the bed and the emptying tank is balanced, thus completing the initial material recovery.

[0006] Cold inert medium purging: A high-purity inert regeneration medium at room temperature is introduced into the emptied dry dehydration bed to purge and replace the high-olefin material remaining in the bed and adsorbent pores. The purged hydrocarbon-containing inert medium is sent to the emptying tank to recover the olefin components, thereby minimizing the olefin load in the subsequent heating stage.

[0007] Heating and desorption: The inert regeneration medium is heated to the preset desorption temperature and then introduced into the drying and dehydration bed. The adsorbent that is saturated with adsorption is desorbed at a constant temperature and pressure, so that the water adsorbed in the micropores of the adsorbent and the residual high olefin material are fully desorbed, forming a hot hydrocarbon desorption gas containing a high concentration of olefins.

[0008] Staged cryogenic condensation and recovery: The hydrocarbon-containing desorbed gas is sent to the staged condensation and recovery unit. Based on the boiling point differences of different olefin components, the gas is cooled step by step to below the dew point of the target olefin, so that the high olefin components in the gas phase are condensed into liquid phase in stages and recovered to the cooling storage tank. The non-condensable gas after two stages of condensation is sent to the flare system for treatment.

[0009] Bed cooling: After the desorption is completed, the heating of the inert regeneration medium is stopped, and room temperature inert regeneration medium is continuously introduced into the bed to cool and replace the bed until the bed temperature drops to room temperature, removing residual moisture and trace hydrocarbons from the bed and preparing for the next cycle of adsorption drying.

[0010] Pressurization and standby: Qualified inert media or high-olefin product materials are injected into the cooled and dehydrated bed to restore the bed to normal operating pressure and maintain a positive pressure seal to prevent air and moisture from entering, thus completing the entire regeneration process and putting the bed into standby mode.

[0011] Due to the adoption of the above technical solution, compared with existing traditional recycling processes, the present invention has the following significant advantages: 1. By using a staged cryogenic condensation and recovery process, the high olefin components in the desorbed gas are condensed and recovered in stages, solving the problem of loss of olefin materials in the direct discharge flare in the traditional process.

[0012] 2. The recovered olefin material can be directly returned to the production system for reuse without additional refining treatment.

[0013] 3. By using a pre-cooled inert medium purging step, residual free olefins in the bed are removed. Combined with temperature control and a completely oxygen-free inert atmosphere, the polymerization reaction of olefins under high temperature conditions is avoided, and the formation of green oil is prevented from damaging the adsorbent and equipment.

[0014] 4. Avoid irreversible capacity decay caused by polymer blockage of adsorbent micropores, extend adsorbent lifespan, reduce bed pressure drop, and decrease the frequency of adsorbent replacement and equipment maintenance.

[0015] 5. Reduce the amount of hydrocarbon materials entering the flare system, reduce pollutant emissions from flare combustion, and at the same time, the staged cooling process can optimize the distribution of cooling capacity according to the boiling point of olefin components, thereby reducing the energy consumption of the refrigeration system.

[0016] 6. It can be achieved simply by adding a staged cryogenic condensation recovery unit to the existing traditional nitrogen regeneration device, without the need for large-scale modification of the original drying bed main equipment and pipelines. It is suitable for the regeneration treatment of drying beds of various high olefin materials.

[0017] 7. The regeneration process steps are seamlessly connected, and all process parameters can be fully automatically controlled through the DCS system. At the same time, each unit is equipped with redundant protection, which can effectively avoid the impact of operating condition fluctuations on the regeneration effect, ensure the stable performance of the drying bed after regeneration, and meet the needs of long-cycle continuous production. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the regeneration and cryogenic recovery process of the high-olefin drying and dehydration bed described in this invention.

[0019] Explanation of reference numerals in the attached diagram: 1. Drying and dehydration bed A; 2. Drying and dehydration bed B; 3. Emptying tank; 4. Nitrogen electric heater; 5. Air cooler (first-stage precooling unit); 6. Cryogenic heat exchanger (second-stage cryogenic unit); 7. Cooling storage tank; 8. Flare system; 9. Valve a; 10. Valve b; 11. Valve c; 12. Valve d; 13. Valve e; 14. Valve f; 15. Valve g; 16. Valve h; 17. Valve i; 18. Valve j; 19. Valve k; 20. Valve m; 21. Valve n; 22. Valve p; 23. Valve q; 24. Valve r; 25. Valve s; 26. Valve t. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific implementation schemes, embodiments, and comparative examples, but the scope of protection of the present invention is not limited thereto.

[0021] Implementation Plan This invention provides a regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed, applicable to the regeneration of fixed-bed adsorption drying units for C4-C12 olefin materials. The adsorbent filled in the drying bed is one or more combinations of alkaline aluminosilicate molecular sieves, modified 3A molecular sieves, or activated alumina-molecular sieve composite adsorbents. When the water content of the material at the outlet of the drying bed is ≥50ppm, the adsorbent is determined to be saturated, and the regeneration process is initiated.

[0022] The specific implementation steps of the regeneration process are as follows: Bed emptying: The adsorption-saturated drying and dehydration bed is removed from the production system, the feed and discharge valves are closed, and the connecting valve between the bed and emptying tank 3 is opened. Relying on the operating pressure of the bed itself, the liquid phase high olefin material in the bed is discharged into the emptying tank 3 until the pressure of the bed and the pressure of the emptying tank 3 reach equilibrium. The connecting valve is then closed, completing the initial material recovery. This step can recover more than 90% of the free liquid phase olefin material in the bed.

[0023] Cold inert medium purging: A high-purity inert regeneration medium at room temperature is introduced into the emptied dry dehydration bed. The inert regeneration medium is selected from high-purity nitrogen, high-purity hydrogen, or high-purity argon with a purity ≥99.9%. The empty tower gas velocity of the inert medium is controlled at 0.25–0.45 m / s, and the system pressure is 0.15–0.35 MPaG. The residual high-olefin material in the bed and adsorbent pores is purged and replaced. The purged hydrocarbon-containing inert medium is sent to the emptying tank 3 to recover the olefin components. The purging time is determined according to the bed volume and the amount of adsorbent, generally 30–90 min. This step can remove the residual free olefins in the bed to the maximum extent and avoid olefin polymerization in the subsequent heating stage.

[0024] Heating and desorption: The inert regeneration medium is heated to a preset desorption temperature of 230-260℃ by a nitrogen electric heater 4, and then introduced into the drying and dehydration bed. The regeneration system pressure is controlled at 0.15-0.35 MPaG, and the empty tower gas velocity of the inert medium is 0.25-0.45 m / s. The adsorbent that is saturated with adsorption is desorbed at a constant temperature to fully desorb the water adsorbed in the micropores of the adsorbent and the residual high olefin material, forming a hot hydrocarbon-containing desorption gas with a high concentration of olefins. The constant temperature desorption time is 2-6 hours to ensure complete desorption of the adsorbent.

[0025] Staged cryogenic condensation and recovery: The hot hydrocarbon-containing gas generated from heating and desorption is sent to the staged condensation and recovery unit. First, it enters the first-stage precooling unit, where air, circulating water, or demineralized water is used as the cooling medium to cool the hydrocarbon-containing gas from 230–260°C to 60–85°C, causing the heavy olefin components in the gas phase to condense into a liquid phase and be recovered to the cooling storage tank 7. The desorption gas after the first-stage cooling continues to enter the second-stage cryogenic unit, where frozen demineralized water, propane, propylene, liquid nitrogen, or liquid ammonia is used as the cryogenic medium to further cool the desorption gas to 0–10°C, causing the remaining light olefin components in the gas phase to condense into a liquid phase and be recovered to the cooling storage tank 7. The non-condensable gas after two stages of condensation is sent to the flare system 8 for treatment.

[0026] Bed cooling: After the desorption is completed, stop the operation of nitrogen electric heater 4, close the heating medium pipeline valve, and continuously introduce room temperature inert regeneration medium into the drying and dehydration bed to cool and replace the bed until the bed temperature drops to room temperature (≤40℃). Remove the residual moisture and trace hydrocarbons in the bed to prepare for the next cycle of adsorption drying. The cooling time is 1 to 3 hours.

[0027] Pressurization and Standby: After the bed cooling is completed, close the inert regeneration medium feed valve, slightly open the product material feed valve of the drying bed, and pressurize the bed with qualified high-olefin product material until the bed pressure returns to the normal operating pressure. Maintain the bed in a positive pressure and sealed state to prevent air and moisture from entering the bed, complete the entire regeneration process, and the bed enters the standby state. The liquid phase olefin material recovered in the cooling storage tank 7 can be directly sent to the drying bed feed system for reuse without additional refining treatment.

[0028] In this implementation plan, addressing the regeneration needs of the drying and dehydration bed for high-olefin materials, a comprehensive regeneration process is constructed based on the boiling point characteristics of olefin materials and the adsorption-desorption mechanism of the adsorbent. This process includes pre-recovery, purging and replacement, isothermal desorption, staged cryogenic recovery, and cooling for later use. First, through two pre-processing steps—bed evacuation and cold inert media purging—over 90% of the free liquid olefins in the bed are recovered. Then, purging and replacement with room-temperature inert media maximizes the removal of residual free olefins from the adsorbent pores, reducing the olefin content in the subsequent heating and desorption stage from the source. This avoids polymerization side reactions caused by the presence of large amounts of olefins at high temperatures, ensuring the structural stability and service life of the adsorbent. Second, in the heating and desorption stage, the desorption temperature is precisely controlled between 230 and 260°C. This temperature range satisfies the deep desorption requirements of water in the molecular sieve adsorbent, ensuring complete recovery of the adsorbent's adsorption capacity, while preventing thermal polymerization and cracking reactions of olefins caused by excessively high temperatures. Combined with a completely oxygen-free inert atmosphere, the formation of green oil polymers is completely eliminated. Then, the core staged cryogenic condensation and recovery unit, based on the boiling point differences of olefin components with different carbon numbers, adopts a staged cooling process of first-stage precooling and second-stage cryogenic condensation: the first-stage precooling uses low-cost air or circulating water as a cold source to cool the high-temperature desorbed gas to 60-85°C, condensing and recovering the heavier olefin components with higher boiling points, while simultaneously reducing the temperature of the desorbed gas and decreasing the cooling load of the second-stage cryogenic unit; the second-stage cryogenic condensation uses chilled brine or low-temperature refrigerant to further cool the desorbed gas to 0-10°C, bringing the lighter olefin components with lower boiling points below the dew point for full condensation and liquefaction, achieving near-complete recovery of olefin components in the desorbed gas. The recovered liquid olefins can be directly returned to the production system for reuse without additional refining costs. Finally, through bed cooling and pressurization standby steps, the regenerated bed is cooled to room temperature and pressurized to a positive pressure sealed state with product material. This ensures the stability of the bed's adsorption drying performance in the next cycle and avoids contamination caused by air and moisture entering the bed, achieving continuous switching operation of the drying bed.

[0029] In addition, it should be noted that the entire process maintains an oxygen-free inert atmosphere, with smooth transitions between steps and precise parameter control. This not only achieves efficient recovery of olefin materials and reduces operating costs, but also effectively suppresses olefin polymerization side reactions, extends the lifespan of the adsorbent, and reduces pollutant emissions. Example

[0030] like Figure 1As shown, this invention provides a regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed. This embodiment is for the regeneration treatment of a C8 olefin (a mixture of components such as octene, methylhepten, dimethylhexene, and trimethylpentene) drying and dehydration bed. The drying bed is filled with modified 3A molecular sieve adsorbent, with a single bed adsorbent filling amount of 12 m³. The normal operating pressure is 0.6 MPaG. When the water content of the material at the outlet of the drying bed is ≥50 ppm, adsorption is determined to be saturated, and the regeneration program is started.

[0031] The specific regeneration process steps are as follows: Bed emptying: The adsorption-saturated drying and dehydration bed B2 is removed from the production system. The feed valve g15 and the discharge valve e13 are closed, and valves i17 and j18 are opened to connect the drying and dehydration bed B2 with the emptying tank 3. Relying on the bed's own pressure of 0.6 MPaG, the liquid phase C8 olefin material in the bed is discharged into the emptying tank 3 until the bed pressure and the emptying tank 3 pressure are balanced to 0.25 MPaG. Then, valve m20 is closed to complete the initial material recovery.

[0032] Cold nitrogen purging: Open valves a9 and c11 to introduce high-purity nitrogen gas (99.99% purity) at room temperature into the drying and dehydration bed B2. Control the nitrogen gas velocity in the empty tower to 0.35 m / s and the system pressure to 0.2 MPaG to purge and replace the bed. The purged hydrocarbon-containing nitrogen gas is sent to the empty tank 3. The purging time is 60 minutes to remove the residual C8 olefin material in the bed to the maximum extent.

[0033] Heating and Desorption: Close valve J18, open valves K19 and N21, stabilize the system pressure at 0.2 MPaG, open valves M20 and P22, control the pressure of cooling storage tank 7 to 0.18 MPaG, start nitrogen electric heater 4, heat high-purity nitrogen to 250℃, and introduce it into the drying and dehydration bed B2 at a flow rate of 4250 kg / h and an empty tower gas velocity of 0.35 m / s to perform isothermal desorption of the adsorbent, so that the moisture in the micropores of the adsorbent desorbs from the C8 olefins to form hydrocarbon-containing desorption gas. The isothermal desorption time is 4 hours.

[0034] Staged cryogenic condensation and recovery: The 250°C hydrocarbon-containing gas generated from heating and desorption is first sent to air cooler 5 (first-stage precooling unit), where air is used as the cooling medium to cool the gas to 70°C, and most of the heavy C8 olefins such as dimethylhexene and trimethylpentene are condensed and recovered; the desorption gas after the first-stage cooling is sent to cryogenic heat exchanger 6 (second-stage cryogenic unit), where demineralized water is used as the cold source to cool the gas to 5°C, and the remaining light C8 olefins such as octene and methylhepten are condensed and recovered; all liquid olefins generated from the two-stage condensation are collected in cooling storage tank 7, and the non-condensable gas is sent to flare system 8.

[0035] Bed cooling: After the analysis is completed, stop the operation of the nitrogen electric heater 4, close valves m20 and p22, and continuously introduce room temperature high-purity nitrogen into the drying and dehydration bed B2 to cool the bed until the bed temperature drops to 35°C. The cooling time is 2 hours, and the bed cooling is completed.

[0036] Pressurization and Standby: After the bed cooling is completed, close valves a9, c11, i17, k19, and n21, and slightly open valve g15. Pressurize the drying and dehydration bed B2 with qualified C8 olefin product material until the bed pressure returns to 0.6 MPaG. Maintain positive pressure sealing of the bed to complete the entire regeneration process, and the bed enters standby status. The recovered olefin material in the cooling storage tank 7 is fed into the drying bed feed system for reuse by opening valve s25.

[0037] The implementation results of this embodiment are as follows: The total recovery rate of C8 olefins reached 98.31%, the water content of the material at the outlet of the regenerated drying bed was stable at ≤10ppm, the adsorption capacity recovery rate of the adsorbent reached 99.2%, no olefin oligomers were detected in the bed, and no polymerization occurred.

[0038] The data analysis is shown in the table below.

[0039] Table 1: Example

[0040] like Figure 1 As shown, this embodiment uses the same C8 olefin drying and dehydration bed as Example 1. The adsorbent type, filling amount, operating pressure and adsorption saturation judgment criteria are all the same as in Example 1. The regeneration program is then started.

[0041] The specific regeneration process steps are as follows: Emptying the bed: Same as step 1 in Example 1, to complete the initial material recovery of the bed.

[0042] Cold nitrogen purging: Open valves a9 and c11 to introduce high-purity nitrogen gas at room temperature and with a purity of 99.99% into the drying and dehydration bed B2. Control the nitrogen gas velocity in the empty tower to be 0.35 m / s, the system pressure to be 0.2 MPaG, and the purging time to be 60 min to complete the bed purging and replacement.

[0043] Heating and Desorption: Close valve J18, open valves K19 and N21, stabilize the system pressure at 0.2 MPaG, open valves M20 and P22, control the pressure of cooling storage tank 7 to 0.18 MPaG, start nitrogen electric heater 4, heat high-purity nitrogen to 230℃, and introduce it into drying and dehydration bed B2 at a flow rate of 4250 kg / h and an empty tower gas velocity of 0.35 m / s. The constant temperature desorption time is 4 hours to complete the adsorbent desorption.

[0044] Staged cryogenic condensation and recovery: The 230°C hydrocarbon-containing desorption gas generated by heating and desorption is first sent to air cooler 5, where air is used as the cooling medium to cool the desorption gas to 80°C and condense to recover heavy C8 olefins; the desorption gas after the first stage of cooling is sent to cryogenic heat exchanger 6, where dehydrated water is used as the cold source to cool the desorption gas to 10°C and condense to recover the remaining light C8 olefins; the liquid olefins are collected in cooling storage tank 7, and the non-condensable gas is sent to flare system 8.

[0045] Bed cooling: The bed cooling process is the same as in Example 1, and the bed cooling is completed.

[0046] Pressurization for standby: Similar to the pressurization for standby in Example 1, the bed is pressurized for standby, and the olefin material is recovered for reuse.

[0047] The implementation results of this embodiment are as follows: The total recovery rate of C8 olefins reached 97.80%, the water content of the material at the outlet of the regenerated drying bed was stable at ≤12ppm, the adsorbent adsorption capacity recovery rate reached 98.7%, no olefin oligomers were detected in the bed, and no polymerization occurred.

[0048] The data analysis is shown in the table below.

[0049] Table 2:

[0050] Comparative Example 1 like Figure 1 As shown, this comparative example uses a traditional nitrogen thermal regeneration process. For the C8 olefin drying and dehydration bed that is exactly the same as in Examples 1 and 2, the adsorbent type, filling amount, operating pressure and adsorption saturation judgment criteria are all the same, and the regeneration program is started.

[0051] The specific regeneration process steps are as follows: Bed emptying: Consistent with the bed emptying in Example 1, the initial material recovery of the bed is completed.

[0052] Cold nitrogen purging: The cold nitrogen purging of the bed is completed in the same manner as in Example 1.

[0053] Heating and desorption: Start the nitrogen electric heater to heat high-purity nitrogen (99.99% purity) to 230℃, and introduce it into the drying and dehydration bed at a flow rate of 4250 kg / h and an empty tower gas velocity of 0.35 m / s. Control the system pressure to 0.2 MPaG and maintain the temperature for 4 hours. All hydrocarbon-containing desorption gases produced are directly sent to the flare system for incineration without any condensation or recovery steps.

[0054] Bed cooling: After the analysis is completed, the heater is stopped and high-purity nitrogen at room temperature is introduced to cool the bed to 35°C for 2 hours.

[0055] Pressurization and standby: After the bed is cooled, pressurize it to 0.6 MPaG with C8 olefin product material to complete regeneration, and the bed enters standby state.

[0056] The implementation results of this comparative example are as follows: the total recovery rate of C8 olefins is 0, all olefin materials in the desorbed gas are sent to the flare for combustion with nitrogen, and the olefin loss in a single cycle of regeneration is comparable to the recovery amount in Example 1; after 10 consecutive regenerations, the adsorption capacity recovery rate of the adsorbent drops to 82.3%, obvious olefin oligomers are detected in the bed, the micropores of the adsorbent are blocked, and the pressure drop of the bed increases by 27% compared with the initial value.

[0057] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A process for regeneration and cryogenic recovery of a high olefin dry dehydration bed, characterized by, This includes the following steps performed sequentially: S1, Bed emptying step: Connect the adsorption saturated high olefin drying and dehydration bed to the emptying tank (3), and use the bed's own pressure to discharge the liquid phase high olefin material in the bed to the emptying tank (3) until the pressure of the bed and the emptying tank (3) are balanced, and the initial material recovery is completed; S2, Cold inert medium purging step: Pass room temperature high purity inert regeneration medium into the emptied dry dehydration bed to purge and replace the high olefin material remaining in the bed and adsorbent pores. The purged hydrocarbon-containing inert medium is sent to the emptying tank (3) to recover the material. S3. Heating and desorption step: After heating the inert regeneration medium to the preset desorption temperature, it is introduced into the drying and dehydration bed to desorb the adsorbent that is saturated with adsorption at a constant temperature, so that the water adsorbed in the pores of the adsorbent and the residual high olefin material are desorbed to form hydrocarbon-containing desorption gas. S4. Staged cryogenic condensation and recovery steps: The hydrocarbon-containing desorbed gas is sent to the staged condensation and recovery unit, and cooled step by step to below the target olefin dew point, so that the high olefin components in the gas phase are condensed into liquid phase and recovered to the cooling storage tank (7). The non-condensable gas is sent to the flare system (8). S5. Bed cooling step: After the analysis is completed, stop heating the inert regeneration medium and continue to introduce room temperature inert regeneration medium into the bed to reduce the bed temperature to room temperature, thus completing the bed cooling. S6. Pressurization and standby step: Pressurize the cooled and dehydrated bed with qualified inert media or high olefin product material to maintain the bed under positive pressure and seal, complete the whole process regeneration, and the bed enters the standby state.

2. The process for regeneration of a high olefin dry desiccant bed and cryogenic recovery according to claim 1, wherein, The inert regeneration medium is selected from at least one of high-purity nitrogen, high-purity hydrogen, and high-purity argon, and the purity of the inert regeneration medium is ≥99.9%.

3. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, In the cold inert medium purging step, the empty tower gas velocity of the inert regeneration medium is 0.25–0.45 m / s, the purging system pressure is 0.15–0.35 MPaG, and the purging time is 30–90 min.

4. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, In the heating and desorption step, the preset desorption temperature is 230-260℃, the regeneration system pressure is 0.15-0.35MPaG, the empty tower gas velocity of the inert regeneration medium is 0.25-0.45m / s, and the isothermal desorption time is 2-6h.

5. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, The staged cryogenic condensation and recovery step adopts a two-stage cooling process, consisting of a primary precooling unit and a secondary cryogenic unit.

6. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 5, characterized in that, The primary precooling unit uses air, circulating water, or demineralized water as the cooling medium to cool the hydrocarbon-containing desorbed gas from 230–260°C to 60–85°C, and condenses and recovers the heavy olefin components.

7. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 5, characterized in that, The secondary cryogenic unit uses cryogenic demineralized water, propane, propylene, liquid nitrogen, or liquid ammonia as the cryogenic medium to cool the desorbed gas after primary precooling to 0-10°C and condense and recover light olefin components.

8. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, The adsorbent filling the high-olefin drying and dehydration bed is selected from at least one of alkaline aluminosilicate molecular sieves, modified 3A molecular sieves, and activated alumina-molecular sieve composite adsorbents.

9. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, The liquid olefin material recovered in the cooling storage tank (7) is directly returned to the high olefin drying feed system for reuse.

10. The regeneration and cryogenic recovery process for a high-olefin drying and dehydration bed according to claim 1, characterized in that, Throughout the regeneration process, the drying and dehydration bed maintains an oxygen-free and inert atmosphere to prevent side reactions of olefin polymerization.

Images