Regeneration method for circulating hexane-based olefin removal adsorbent in ethylene propylene rubber production

Abstract

This invention relates to the field of organic chemical technology, and particularly to a regeneration method for olefin removal adsorbents in the production of ethylene propylene rubber from recycled hexane. The method comprises the following steps: Step 1: Online regeneration with hot nitrogen: After the adsorption tank is prepared for online regeneration, nitrogen is heated by steam through a heater. The heated nitrogen then passes through the adsorption tank to remove olefins physically adsorbed on the HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents, restoring the adsorbents' olefin adsorption capacity. Step 2: Offline regeneration: After several online regenerations, the HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents are removed from the adsorption tank for offline regeneration. This invention enables the restoration of olefin adsorption capacity in the recycled hexane used for ethylene propylene rubber production, using a regeneration method, thereby achieving long-term, stable operation of hexane olefin removal and improving the quality of ethylene propylene rubber products.

Description

Technical Field

[0001] This invention relates to the field of organic chemical technology, and in particular to a method for regenerating a circulating hexane-based olefin removal adsorbent in the production of ethylene propylene rubber. Background Technology

[0002] The ethylene propylene rubber (EPR) production method employs solvent polymerization using n-hexane as the solvent, which is recyclable. The hexane from the solvent recovery unit of the EPR production plant contains trace amounts of C6-C9 olefins, increasing the bromine value of the hexane in the system from 200 mg / kg to 1000 mg / kg. When the bromine value reaches 700 mg / kg, the hexane containing a high concentration of CPD (cyclopentadiene) in the solvent recovery unit is discharged to fuel oil tanks for temporary storage. Depending on the fuel oil tank level, the hexane is periodically discharged for desorption and hydrogenation treatment before being returned. The annual discharge volume is approximately 1000 tons, with a processing cost of 3,000-4,000 RMB / ton. As production operation time increases, the C6-C9 olefin content in the hexane increases, affecting the quality of the EPR product. This process is characterized by a long process route, complex operation, unstable hydrogen content in the system, low safety performance, and high cost. To improve the intrinsic quality of ethylene propylene rubber and reduce the odor of the finished rubber, Jilin Petrochemical has developed an adsorbent and process for recycling hexane in ethylene propylene rubber, both of which have been submitted for invention patents. In order to ensure the long-term stable operation of this adsorption process, it is necessary to develop a regeneration method for the adsorbent used to remove olefins from hexane.

[0003] Adsorption is a low-energy-consumption solid-gas or solid-liquid separation technology widely used in chemical, petrochemical, fine chemical, light industry, and other industries. The principle of olefin removal by molecular sieve adsorbents such as HY, HMCM-22, HMCM-49, and Hβ involves two types of adsorption: physical adsorption and chemical adsorption. Physical adsorption: Circulating hexane and olefins enter the molecular sieve pores and interact with the adsorbent through intermolecular forces, forming physical adsorption. Chemical adsorption: Circulating hexane and olefins enter the molecular sieve pores, and the olefins form carbocations with the acid centers of the HY, HMCM-22, HMCM-49, and Hβ molecular sieves. These carbocations cause the olefins to oligomerize, and the oligomers cover the acid centers of the molecular sieve, forming chemical adsorption. As production continues, olefin oligomers accumulate on the inner surface of the molecular sieve, gradually weakening its olefin adsorption capacity. Eventually, the olefin adsorption capacity cannot meet production needs, requiring regeneration.

[0004] The regeneration of adsorbents is similar in principle to that of catalysts, with one type being online regeneration and the other offline regeneration. Online regeneration occurs during production without introducing recycled hexane; instead, the adsorbent is heated to remove olefins adsorbed within the molecular sieve pores. Online regeneration is limited by heating conditions, generally below 200°C; under these conditions, the removed olefins are those physically adsorbed. Offline regeneration involves removing the adsorbent from the production unit for regeneration. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for regenerating olefin adsorbents in the recycled hexane used for producing ethylene propylene rubber. This method restores the olefin adsorption capacity of HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents in the recycled hexane used for producing ethylene propylene rubber, which have lost their olefin adsorption capacity, through a regeneration method. This enables long-term and stable operation of hexane olefin desorption and improves the quality of ethylene propylene rubber products.

[0006] The technical solution adopted in this invention is: a regeneration method for a circulating hexane-based olefin removal adsorbent in the production of ethylene propylene rubber, the steps of which are as follows:

[0007] Step 1: Hot Nitrogen Online Regeneration: After the adsorption tank is prepared for online regeneration, steam is used to heat the nitrogen through a heater. The heated nitrogen is then passed through the adsorption tank to remove olefins physically adsorbed on HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents, restoring the adsorbents' ability to adsorb olefins. Full component analysis of the tail gas is performed during the online regeneration process.

[0008] Step 2: Offline Regeneration: After several online regenerations, the HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents are removed from the adsorption tank for offline regeneration. The offline regeneration steps are as follows:

[0009] a. Calcination: The HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents unloaded from the adsorption tank are sent to the calcination furnace for calcination to remove organic matter from the adsorbents;

[0010] b. Exchange: Place the calcined adsorbent in an exchange tank or exchange vessel, add exchange solution for exchange, remove the exchange solution, and then wash with demineralized water. Repeat 3 cycles to remove trace metal impurities adsorbed in the adsorbent.

[0011] c. Drying and calcination: The adsorbent, after removing trace metal impurities, is dried and calcined.

[0012] Furthermore, the online regeneration preparation steps for the adsorption tank in step one are as follows: The online regeneration preparation steps for the adsorption tank are as follows: The adsorption tank stops the hexane adsorption operation, exits the hexane, is isolated from the production system, and is purged with nitrogen to confirm that there is no hexane liquid.

[0013] Furthermore, in step one, the hot nitrogen is produced by heating the nitrogen in the production system with steam from the ethylene propylene rubber production unit through a heater, and the temperature of the hot nitrogen is controlled by adjusting the pressure and flow rate of the steam in stages.

[0014] Furthermore, the control of the online regeneration temperature of hot nitrogen in step one: online regeneration temperature control is the control of the outlet temperature of the adsorption tank. The outlet temperature of the adsorption tank is controlled by adjusting the flow rate of hot nitrogen. The outlet temperature of the adsorption tank is controlled at 140-230℃, preferably 170-200℃.

[0015] Furthermore, the online regeneration time of hot nitrogen in step one is 4-10 days.

[0016] Furthermore, after online regeneration 2-3 times in step two, offline regeneration is performed.

[0017] Furthermore, in step two, the roasting temperature of calcination a is 450-680℃, and the roasting time is 1-8 hours. Furthermore, in step two, the exchange solution in the exchange process b is any one of ammonium nitrate aqueous solution, citric acid aqueous solution, and nitric acid aqueous solution.

[0018] Furthermore, when the exchange liquid is an aqueous solution of ammonium nitrate, the mass concentration of the aqueous solution of ammonium nitrate is 1%-10%, preferably 2%-5%; the exchange temperature is 20-85℃; and the exchange time is 2-24h.

[0019] When the exchange solution is an aqueous solution of citric acid, the mass concentration of the aqueous solution of citric acid is 0.1%-10%, preferably 0.8%-2.5%; the exchange temperature is 20-85℃, preferably 60-75℃; and the exchange time is 2-24h.

[0020] When the exchange liquid is an aqueous nitric acid solution, the mass concentration of the aqueous nitric acid solution is 0.01%-8%; the exchange temperature is 20-70℃, preferably 50-65℃; and the exchange time is 2-24h.

[0021] Furthermore, in step two, the washing solution used for the demineralized water washing during the b-exchange process is demineralized water, with a liquid-to-solid volume ratio of 1.3-5:1 between the demineralized water and the adsorbent; the washing temperature is 20-75℃; and the washing time is 0.5-4h.

[0022] Furthermore, in step two, c, drying and calcination, the drying temperature is 110-130℃ and the drying time is 4-8 hours.

[0023] Furthermore, in step two, c, the drying and calcination processes, the calcination temperature and time vary depending on the exchange solution:

[0024] When the exchange solution is an aqueous solution of ammonium nitrate: the calcination temperature is 350-550℃; the calcination time is 1-8 hours.

[0025] When the exchange solution is an aqueous solution of citric acid: the calcination temperature is 450-580℃; the calcination time is 1-10h; when the exchange solution is an aqueous solution of nitric acid: the calcination temperature is 350-550℃; the calcination time is 1-8h.

[0026] The beneficial effects of this invention are:

[0027] (1) The present invention restores the ability of HY, HMCM-22, HMCM-49 and Hβ molecular sieve adsorbents that have lost their ability to adsorb olefins in the recycled hexane used for the production of ethylene propylene rubber by regeneration method, thereby achieving long-term and stable operation of hexane desorption of olefins and improving the quality of ethylene propylene rubber products.

[0028] (2) The present invention adopts a combination of online regeneration method and offline regeneration method. The online regeneration method is easy to operate and has a high adsorbent recovery rate in the early stage; the offline regeneration method in the later stage has a high adsorbent recovery rate. Attached Figure Description

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a schematic diagram of the online hot nitrogen regeneration process of the present invention. Detailed Implementation

[0031] A method for regenerating a circulating hexane-based olefin removal adsorbent in the production of ethylene propylene rubber, comprising the following steps:

[0032] Step 1: As Figure 1 As shown, when the bromine value at the outlet of the adsorption tank is 20% of the inlet bromine value, the adsorption tank prepares for online regeneration: the adsorption tank stops hexane adsorption, exits hexane, is isolated from the production system, and is purged with nitrogen to confirm the absence of hexane liquid. At this time, the heater steam valve is opened to heat nitrogen for online regeneration. The flow rate of hot nitrogen is adjusted to control the outlet temperature of the adsorption tank, and a full component analysis of the tail gas is performed. After online regeneration is completed, the heater steam valve is closed to cool down to the process operating temperature, and the system is connected to the production system. Hexane is then added for production application.

[0033] Adsorption evaluation after hot nitrogen online regeneration: After confirming that the online regeneration is qualified, the temperature is lowered to the process operating temperature, and production is started. Based on the amount of olefins adsorbed in hexane during production and the amount of olefins adsorbed in fresh adsorbent, the online regeneration recovery rate is calculated, and the number of online regeneration cycles is determined based on the regeneration recovery rate.

[0034] Step 2: Offline Regeneration: After online regeneration 2-3 times, remove the HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents from the adsorption tank for offline regeneration. The offline regeneration steps are as follows:

[0035] a. Calcination: The HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents unloaded from the adsorption tank are sent to the calcination furnace for calcination to remove organic matter from the adsorbents;

[0036] b. Exchange: Place the calcined adsorbent in an exchange tank or exchange vessel, add exchange solution for exchange, remove the exchange solution, and then wash with demineralized water. Repeat 3 cycles to remove trace metal impurities adsorbed in the adsorbent.

[0037] c. Drying and calcination: The adsorbent, after removing trace metal impurities, is dried and calcined.

[0038] Evaluation of the adsorption performance of the regenerated adsorbent: The regenerated adsorbent is divided into molecular sieve adsorbents regenerated online and molecular sieve adsorbents regenerated offline; Industrial operating conditions: Adsorption temperature: room temperature - 60℃, adsorption pressure: 0.3-0.7MPa, space velocity: 0.1-0.8h. -1 The bromine value at the inlet of the circulating hexane is 160-810 mgBr / 100g; the bromine values ​​at the inlet and outlet of the adsorption tank (device) are measured, and the unit adsorption capacity of the olefin is calculated.

[0039] Example 1

[0040] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of EBZ-100 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1500 m³ / h, and the adsorption tank outlet temperature was controlled at 140°C. A full component analysis of the tail gas was performed, and online regeneration continued for 10 days. The heater steam valve was then closed to cool the tank to 40°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.5%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0041] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1500 m³ / h, and the adsorption tank outlet temperature is controlled at 170°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 55.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0042] The third online regeneration was performed. Hexane was removed, and the system was isolated. Nitrogen was used for purging. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1500 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 5 days. The heater steam valve was then closed to cool the system to 50°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 36.5%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0043] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of EBZ-100 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 450℃, calcination time: 8 hours. After cooling, load into an exchange tank (or apparatus), add 1% ammonium nitrate aqueous solution for the first exchange at 85℃ for 2 hours. Discharge the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 2% ammonium nitrate aqueous solution for the second exchange at 65℃ for 5 hours. Discharge the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 5% ammonium nitrate aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 8 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.5%.

[0044] Example 2

[0045] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-49 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1600 m³ / h, and the adsorption tank outlet temperature was controlled at 190°C. A full component analysis of the tail gas was performed, and online regeneration continued for 5 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine the first online regeneration recovery rate to be 64.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0046] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1300 m³ / h, and the adsorption tank outlet temperature is controlled at 160°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0047] The third online regeneration was performed. Hexane was removed and the system isolated from the production system. The system was purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 4 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 35.8%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0048] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-49 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 650℃, calcination time: 1 hour. After cooling, load into an exchange tank (or apparatus), add 0.1% citric acid aqueous solution for the first exchange at 85℃ for 2 hours. Discard the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 0.8% citric acid aqueous solution for the second exchange at 65℃ for 5 hours. Discard the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% citric acid aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcination device at 450°C for 6 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.7%.

[0049] Example 3

[0050] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-22 adsorbent. Initially, the bromine value of the circulating hexane was 590 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1800 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was performed, and online regeneration continued for 4 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0051] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 180°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 6 days. The heater steam valve is then closed to cool the system to 40°C. The system is then reconnected to the production system, and hexane is added for production application. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0052] The third online regeneration was performed. Hexane was removed and the system isolated from production. The system was purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 4 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to production, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 35.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0053] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-22 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 500℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 0.01% nitric acid aqueous solution for the first exchange at 20℃ for 4 hours. Dispose of the exchange solution, add 5 times the volume of demineralized water, and wash at 20℃ for 2 hours. Remove the demineralized water, add 0.2% nitric acid aqueous solution for the second exchange at 50℃ for 2 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% nitric acid aqueous solution was added for a third exchange at 65°C for 2 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 50°C for 2 hours. The solution was then transferred to a drying device at 120°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 3 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.6%.

[0054] Example 4

[0055] The adsorption tank of the ethylene propylene rubber production unit is filled with 12.5 tons of β-adsorbent. Initially, the bromine value of the circulating hexane is 610 mgBr / 100g. When the bromine value at the outlet of the adsorption tank is 20% of the inlet bromine value, online regeneration is determined to be necessary. Based on the actual production situation, hexane is withdrawn, isolated from the production system, and purged with nitrogen. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The flow rate of hot nitrogen is adjusted to 1500 m³ / h, and the outlet temperature of the adsorption tank is controlled at 180°C. A full component analysis of the tail gas is performed, and online regeneration continues for 7 days. The heater steam valve is then closed to cool the tank to 50°C. The tank is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption amount, and thus calculate the recovery rate of the first online regeneration to be 65.9%. When the adsorption rate reaches 15%, it is determined that the production demand is not met, and a second online regeneration is required.

[0056] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 230°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 4 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 55.7%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0057] The third online regeneration was performed. Hexane was removed, and the system was isolated. Nitrogen was used for purging. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 6 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 34.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0058] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-49 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 550℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 5% citric acid aqueous solution for the first exchange at 85℃ for 2 hours. Dispose of the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 0.8% citric acid aqueous solution for the second exchange at 65℃ for 5 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% citric acid aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcination device at 540°C for 4 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.8%.

[0059] Example 5

[0060] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of EBZ-100 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 190°C. A full component analysis of the tail gas was performed, and online regeneration continued for 5 days. The heater steam valve was then closed to cool the tank to 40°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0061] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1400 m³ / h, and the adsorption tank outlet temperature is controlled at 180°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.9%. When the adsorption rate reaches 15%, it is determined that production requirements are not met, and offline regeneration is necessary.

[0062] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-49 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 550℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 5% citric acid aqueous solution for the first exchange at 85℃ for 2 hours. Dispose of the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 0.8% citric acid aqueous solution for the second exchange at 65℃ for 5 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% citric acid aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcination device at 540°C for 4 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.8%.

[0063] Example 6

[0064] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of EBZ-100 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1500 m³ / h, and the adsorption tank outlet temperature was controlled at 140°C. A full component analysis of the tail gas was performed, and online regeneration continued for 10 days. The heater steam valve was then closed to cool the tank to 40°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.5%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0065] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1500 m³ / h, and the adsorption tank outlet temperature is controlled at 170°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 55.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0066] The third online regeneration was performed. Hexane was removed, and the system was isolated. Nitrogen was used for purging. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1500 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 5 days. The heater steam valve was then closed to cool the system to 50°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 36.5%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0067] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-22 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 500℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 0.01% nitric acid aqueous solution for the first exchange at 20℃ for 4 hours. Dispose of the exchange solution, add 5 times the volume of demineralized water, and wash at 20℃ for 2 hours. Remove the demineralized water, add 0.2% nitric acid aqueous solution for the second exchange at 50℃ for 2 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% nitric acid aqueous solution was added for a third exchange at 65°C for 2 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 50°C for 2 hours. The solution was then transferred to a drying device at 120°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 3 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.6%.

[0068] Example 7

[0069] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-49 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1600 m³ / h, and the adsorption tank outlet temperature was controlled at 190°C. A full component analysis of the tail gas was performed, and online regeneration continued for 5 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine the first online regeneration recovery rate to be 64.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0070] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1300 m³ / h, and the adsorption tank outlet temperature is controlled at 160°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand cannot be met, and offline regeneration is required.

[0071] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-22 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 500℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 0.01% nitric acid aqueous solution for the first exchange at 20℃ for 4 hours. Dispose of the exchange solution, add 5 times the volume of demineralized water, and wash at 20℃ for 2 hours. Remove the demineralized water, add 0.2% nitric acid aqueous solution for the second exchange at 50℃ for 2 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% nitric acid aqueous solution was added for a third exchange at 65°C for 2 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 50°C for 2 hours. The solution was then transferred to a drying device at 120°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 3 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.6%.

[0072] Example 8

[0073] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-49 adsorbent. Initially, the bromine value of the circulating hexane was 480 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1600 m³ / h, and the adsorption tank outlet temperature was controlled at 190°C. A full component analysis of the tail gas was performed, and online regeneration continued for 5 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and cumulative olefin adsorption, and determine the first online regeneration recovery rate to be 64.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0074] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1300 m³ / h, and the adsorption tank outlet temperature is controlled at 160°C. A full component analysis of the tail gas is performed. Online regeneration lasts 7 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand cannot be met, and offline regeneration is required.

[0075] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-49 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 550℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 5% citric acid aqueous solution for the first exchange at 85℃ for 2 hours. Dispose of the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 0.8% citric acid aqueous solution for the second exchange at 65℃ for 5 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% citric acid aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcination device at 540°C for 4 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.8%.

[0076] Example 9

[0077] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-22 adsorbent. Initially, the bromine value of the circulating hexane was 590 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1800 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was performed, and online regeneration continued for 4 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0078] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 180°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 6 days. The heater steam valve is then closed to cool the system to 40°C. The system is then reconnected to the production system, and hexane is added for production application. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0079] The third online regeneration was performed. Hexane was removed and the system isolated from production. The system was purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 4 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to production, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 35.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0080] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-49 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 550℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 5% citric acid aqueous solution for the first exchange at 85℃ for 2 hours. Dispose of the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 0.8% citric acid aqueous solution for the second exchange at 65℃ for 5 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% (w / w) citric acid aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of the adsorbent was added as demineralized water. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcination device at 540°C for 4 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.8%.

[0081] Example 10

[0082] The adsorption tank of the ethylene propylene rubber production unit was filled with 12.5 tons of MCM-22 adsorbent. Initially, the bromine value of the circulating hexane was 590 mgBr / 100g. When the bromine value at the adsorption tank outlet was 20% of the inlet bromine value, online regeneration was deemed necessary. Based on actual production conditions, hexane was withdrawn, the unit was isolated from the production system, and purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1800 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was performed, and online regeneration continued for 4 days. The heater steam valve was then closed to cool the tank to 60°C. The unit was then reconnected to the production system, hexane was added, and production was initiated. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption, and determine that the first online regeneration recovery rate was 65.8%. When the adsorption rate reached 15%, it was determined that the production demand was insufficient, necessitating a second online regeneration.

[0083] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 180°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 6 days. The heater steam valve is then closed to cool the system to 40°C. The system is then reconnected to the production system, and hexane is added for production application. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 54.5%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0084] The third online regeneration was performed. Hexane was removed and the system isolated from production. The system was purged with nitrogen. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 4 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to production, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 35.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0085] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of EBZ-100 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 450℃, calcination time: 8 hours. After cooling, load into an exchange tank (or apparatus), add 1% ammonium nitrate aqueous solution for the first exchange at 85℃ for 2 hours. Discharge the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 2% ammonium nitrate aqueous solution for the second exchange at 65℃ for 5 hours. Discharge the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 5% ammonium nitrate aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 8 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.5%.

[0086] Example 11

[0087] The adsorption tank of the ethylene propylene rubber production unit is filled with 12.5 tons of β-adsorbent. Initially, the bromine value of the circulating hexane is 610 mgBr / 100g. When the bromine value at the outlet of the adsorption tank is 20% of the inlet bromine value, online regeneration is determined to be necessary. Based on the actual production situation, hexane is withdrawn, isolated from the production system, and purged with nitrogen. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The flow rate of hot nitrogen is adjusted to 1500 m³ / h, and the outlet temperature of the adsorption tank is controlled at 180°C. A full component analysis of the tail gas is performed, and online regeneration continues for 7 days. The heater steam valve is then closed to cool the tank to 50°C. The tank is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption amount, and thus calculate the recovery rate of the first online regeneration to be 65.9%. When the adsorption rate reaches 15%, it is determined that the production demand is not met, and a second online regeneration is required.

[0088] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 230°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 4 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 55.7%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0089] The third online regeneration was performed. Hexane was removed, and the system was isolated. Nitrogen was used for purging. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 6 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 34.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0090] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of EBZ-100 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 450℃, calcination time: 8 hours. After cooling, load into an exchange tank (or apparatus), add 1% ammonium nitrate aqueous solution for the first exchange at 85℃ for 2 hours. Discharge the exchange solution, add 1.3 times the volume of demineralized water, and wash at 20℃ for 4 hours. Remove the demineralized water, add 2% ammonium nitrate aqueous solution for the second exchange at 65℃ for 5 hours. Discharge the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 5% ammonium nitrate aqueous solution was added for a third exchange at 75°C for 4 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 65°C for 2 hours. The solution was then transferred to a drying device at 110°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 8 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.5%.

[0091] Example 12

[0092] The adsorption tank of the ethylene propylene rubber production unit is filled with 12.5 tons of β-adsorbent. Initially, the bromine value of the circulating hexane is 610 mgBr / 100g. When the bromine value at the outlet of the adsorption tank is 20% of the inlet bromine value, online regeneration is determined to be necessary. Based on the actual production situation, hexane is withdrawn, isolated from the production system, and purged with nitrogen. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The flow rate of hot nitrogen is adjusted to 1500 m³ / h, and the outlet temperature of the adsorption tank is controlled at 180°C. A full component analysis of the tail gas is performed, and online regeneration continues for 7 days. The heater steam valve is then closed to cool the tank to 50°C. The tank is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value, calculate the adsorption rate and the cumulative olefin adsorption amount, and thus calculate the recovery rate of the first online regeneration to be 65.9%. When the adsorption rate reaches 15%, it is determined that the production demand is not met, and a second online regeneration is required.

[0093] Second online regeneration. Hexane is removed, and the system is isolated. Nitrogen is used for purging. When no liquid hexane remains, the heater steam valve is opened, and nitrogen is heated to 230°C for online regeneration. The hot nitrogen flow rate is adjusted to 1600 m³ / h, and the adsorption tank outlet temperature is controlled at 230°C. A full component analysis of the tail gas is performed. Online regeneration lasts for 4 days. The heater steam valve is then closed to cool the system to 50°C. The system is then reconnected to the production system, hexane is added, and production is initiated. Samples are taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption are calculated, resulting in a second online regeneration recovery rate of 55.7%. When the adsorption rate reaches 15%, it is determined that the production demand is insufficient, requiring a third online regeneration.

[0094] The third online regeneration was performed. Hexane was removed, and the system was isolated. Nitrogen was used for purging. When no liquid hexane remained, the heater steam valve was opened, and nitrogen was heated to 230°C for online regeneration. The hot nitrogen flow rate was adjusted to 1700 m³ / h, and the adsorption tank outlet temperature was controlled at 230°C. A full component analysis of the tail gas was conducted. Online regeneration lasted 6 days. The heater steam valve was then closed to cool the system to 30°C. The system was then reconnected to the production system, and hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a third online regeneration recovery rate of 34.1%. This was determined to be insufficient to meet production needs, necessitating offline regeneration.

[0095] Offline regeneration. Disconnect hexane and isolate from the production system. Purge with nitrogen until no liquid hexane remains, then unload 12.5 tons of MCM-22 adsorbent. Send to a tunnel kiln (furnace) for offline regeneration. Calcination temperature: 500℃, calcination time: 2 hours. After cooling, load into an exchange tank (or apparatus), add 0.01% nitric acid aqueous solution for the first exchange at 20℃ for 4 hours. Dispose of the exchange solution, add 5 times the volume of demineralized water, and wash at 20℃ for 2 hours. Remove the demineralized water, add 0.2% nitric acid aqueous solution for the second exchange at 50℃ for 2 hours. Dispose of the exchange solution, add 1.4 times the volume of demineralized water, and wash at 50℃ for 1 hour. After removing the demineralized water, a 2.5% nitric acid aqueous solution was added for a third exchange at 65°C for 2 hours. The exchange solution was then released, and 1.6 times the volume of demineralized water was added. The solution was washed at 50°C for 2 hours. The solution was then transferred to a drying device at 120°C for 4 hours. Next, it was transferred to a calcining device at 500°C for 3 hours. Immediately afterward, it was loaded into the adsorption tank of the ethylene propylene rubber production unit and connected to the production system. Hexane was added for production application. Samples were taken from the inlet and outlet of the adsorption tank to analyze the bromine value. The adsorption rate and cumulative olefin adsorption were calculated, resulting in a first offline regeneration recovery rate of 99.6%.

[0096] In summary, according to Examples 1-12, the online regeneration method of the present invention is easy to operate and has a high adsorbent recovery rate in the early stage, and the offline regeneration method in the later stage has a high adsorbent recovery rate. The regeneration method restores the adsorbent's ability to adsorb olefins.

[0097] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A method for regenerating a circulating hexane-based olefin removal adsorbent in the production of ethylene propylene rubber, characterized in that: The steps of this method are as follows: Step 1: Hot Nitrogen Online Regeneration: After the adsorption tank is prepared for online regeneration, steam is used to heat the nitrogen through a heater. The heated nitrogen is then passed through the adsorption tank to remove the olefins physically adsorbed on the molecular sieve adsorbent, restoring the adsorbent's ability to adsorb olefins. Full component analysis of the tail gas is performed during the online regeneration process. Step 2: Offline Regeneration: After several online regenerations, the molecular sieve adsorbent is removed from the adsorption tank for offline regeneration. The offline regeneration steps are as follows: a. Calcination: The molecular sieve adsorbent unloaded from the adsorption tank is sent to a calcination furnace for calcination to remove organic matter from the adsorbent; b. Exchange: The calcined adsorbent is placed in an exchange tank or exchange vessel, an exchange solution is added for exchange, the exchange solution is removed, and then the adsorbent is washed with demineralized water. This process is repeated for 3 cycles to remove trace metal impurities adsorbed in the adsorbent. The exchange solution is any one of ammonium nitrate aqueous solution, citric acid aqueous solution, and nitric acid aqueous solution. c. Drying and calcination: The adsorbent used to remove trace metal impurities is dried and calcined. The molecular sieve adsorbents mentioned above are selected from HY, HMCM-22, HMCM-49, and Hβ molecular sieve adsorbents.

2. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: The steps for online regeneration preparation of the adsorption tank in step one are as follows: the adsorption tank stops hexane adsorption operation, hexane is removed, it is isolated from the production system, and it is purged with nitrogen to confirm that there is no hexane liquid.

3. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: In step one, the hot nitrogen is produced by heating the nitrogen in the production system with steam from the ethylene propylene rubber production unit through a heater. The temperature of the hot nitrogen is controlled by adjusting the pressure and flow rate of the steam.

4. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: The control of the online regeneration temperature of hot nitrogen in step one: online regeneration temperature control is the control of the outlet temperature of the adsorption tank. The outlet temperature of the adsorption tank is controlled by adjusting the flow rate of hot nitrogen, and the outlet temperature of the adsorption tank is controlled at 140-230℃.

5. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 4, characterized in that: The outlet temperature of the adsorption tank is controlled at 170-200℃.

6. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: The online regeneration time for hot nitrogen in step one is 4-10 days.

7. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: After online regeneration 2-3 times in step two, offline regeneration is performed.

8. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: In step two, the roasting temperature is 450-680℃ and the roasting time is 1-8h.

9. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: When the exchange liquid is an aqueous solution of ammonium nitrate, the mass concentration of the aqueous solution of ammonium nitrate is 1%-10%, the exchange temperature is 20-85℃, and the exchange time is 2-24h. When the exchange solution is an aqueous solution of citric acid, the mass concentration of the aqueous solution of citric acid is 0.1%-10%, the exchange temperature is 20-85℃, and the exchange time is 2-24h. When the exchange liquid is an aqueous nitric acid solution, the mass concentration of the aqueous nitric acid solution is 0.01%-8%, the exchange temperature is 20-70℃, and the exchange time is 2-24h.

10. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 9, characterized in that: When the exchange medium is an aqueous solution of ammonium nitrate, the mass concentration of the aqueous solution of ammonium nitrate is 2%-5%; When the exchange medium is an aqueous solution of citric acid, the mass concentration of the aqueous solution of citric acid is 0.8%-2.5%, and the exchange temperature is 60-75℃; When the exchange liquid is an aqueous solution of nitric acid, the exchange temperature of the aqueous solution of nitric acid is 50-65℃.

11. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: In step two, the washing solution used in the b-exchange process is demineralized water, with a liquid-to-solid volume ratio of 1.3-5:1 between the demineralized water and the adsorbent; the washing temperature is 20-75℃; and the washing time is 0.5-4h.

12. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: In step two, c, during drying and calcination, the drying temperature is 110-130℃ and the drying time is 4-8 hours.

13. The regeneration method for the circulating hexane-removing olefin adsorbent in the production of ethylene propylene rubber according to claim 1, characterized in that: In step two, c, during drying and calcination, the calcination temperature and time vary depending on the exchange solution. When the exchange solution is an aqueous solution of ammonium nitrate: the calcination temperature is 350-550℃; the calcination time is 1-8 hours. When the ion exchange solution is an aqueous solution of citric acid: the calcination temperature is 450-580℃; the calcination time is 1-10h. When the ion exchange solution is an aqueous nitric acid solution: the calcination temperature is 350-550℃; the calcination time is 1-8h.

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