Olefin gas purification method

Abstract

The invention relates to the technical field of gas purification, and particularly provides an olefin gas purification method. The olefin gas purification method comprises the following steps: feeding a liquid impurity removal agent into a purifier to form an impurity removal agent liquid level at the bottom of the purifier, continuously conveying the impurity removal agent in the purifier from a bottom outlet of the purifier to a top inlet of the purifier by utilizing an impurity removal agent circulating pipeline, and feeding olefin gas into the purifier from the bottom inlet of the purifier, olefin gas passes through the impurity removal agent liquid level to be purified for the first time, the olefin gas purified for the first time rises in the purifier and makes contact with the impurity removal agent entering from the top inlet in the rising process to be purified for the second time, and the olefin gas purified for the second time is output to a gas using area from the purified olefin gas outlet. The olefin gas purification method provided by the invention is used for removing various impurities in the olefin gas at one time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of gas purification, and particularly to a method for purifying olefin gas. Background Art

[0002] In the olefin polymerization industry, the purification of olefin monomers is crucial for catalyst efficiency, product performance, and production cost control. For example, in monomer olefins such as ethylene and propylene, impurities such as carbon dioxide, oxygen, and water can poison the olefin polymerization catalyst, resulting in a decrease in catalyst activity, affecting the normal operation of the device and the quality of the polymerization product.

[0003] Currently, most of the related technologies remove impurities in olefin gas by passing the olefin gas through a purification column system before entering the reaction device. The purification column generally uses molecular sieves loaded with active components for chemical impurity removal, and often requires multiple purification columns to be connected in series. This method has many drawbacks, such as a large floor area of the equipment, low impurity removal efficiency, easy saturation of the molecular sieve, frequent replacement or high-temperature regeneration required, cumbersome operation, and high cost. Summary of the Invention

[0004] In view of the above problems, the present disclosure is proposed. The present disclosure provides a method for purifying olefin gas, which can remove multiple impurities in olefin gas at one time, simplifies the operation process, and reduces the cost.

[0005] According to one aspect of the present disclosure, there is provided a method for purifying olefin gas, including the following steps:

[0006] Send a liquid impurity remover into the purifier so that an impurity remover liquid level is formed at the bottom of the purifier;

[0007] Use an impurity remover circulation pipeline to continuously transport the impurity remover in the purifier from the bottom outlet of the purifier to the top inlet of the purifier;

[0008] Send olefin gas into the purifier from the bottom inlet of the purifier, and the olefin gas is purified once through the impurity remover liquid level;

[0009] The olefin gas after the first purification rises in the purifier and contacts the impurity remover coming in from the top inlet during the rising process for secondary purification;

[0010] The olefin gas after the secondary purification is output from the purified olefin gas outlet to the gas-using area.

[0011] Compared with the prior art, the method for purifying olefin gas provided by the present disclosure has the following advantages:

[0012] In the olefin gas purification method provided by the embodiments of the present disclosure, first, a liquid impurity remover can be fed into the purifier. As the impurity remover is continuously injected, a stable liquid level of the impurity remover gradually forms at the bottom of the purifier. Then, by using the impurity remover circulation pipeline, the impurity remover in the purifier can be continuously and stably transported from the bottom outlet to the top inlet, enabling the recycling of the impurity remover in the purifier. Subsequently, the olefin gas to be purified is fed into the bottom inlet of the purifier. After entering the purifier, the olefin gas immediately passes through the liquid level of the impurity remover. During this process, some impurities in the gas are quickly dissolved in the impurity remover or chemically react with the impurity remover, thereby achieving primary purification and initially removing a large amount of obvious impurities. The olefin gas after primary purification continuously rises in the purifier and contacts the impurity remover entering from the top inlet, enabling the uncompletely removed impurities to further react with or dissolve in the impurity remover, achieving a more refined secondary purification. Finally, the olefin gas after secondary purification is output from the purified olefin gas outlet to the gas consumption area, thus providing a pure and reliable olefin gas source for subsequent industrial production or other applications. Therefore, the olefin gas purification method of the present disclosure does not require a series connection of multiple purification columns, avoiding the problems of large floor area occupied by multiple purification columns and easy saturation of molecular sieves, which require frequent replacement or high-temperature regeneration. Therefore, it not only simplifies the operation process but also reduces the production cost.

[0013] In addition, through the olefin gas purification method of the present disclosure, the content of impurities in the olefin gas can be significantly reduced to the ppb level, and multiple cycle purifications are not required, thus being suitable for the production of electronic-grade or photovoltaic-grade polyolefin resins. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] By describing the embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more obvious. The drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation to the present disclosure. In the drawings, the same reference numerals generally represent the same components or steps.

[0015] Figure 1 is the preparation flow chart of the olefin gas purification method of the embodiments of the present disclosure;

[0016] Figure 2 is a schematic diagram of the olefin gas purification system provided by the embodiments of the present disclosure.

[0017] Reference Numerals:

[0018] 100 - Purifier, 110 - First olefin gas pipeline, 120 - Second olefin gas pipeline, 200 - Impurity removal agent circulation pipeline, 210 - Circulation pump, 300 - Liquid impurity removal agent, 400 - Atomizer, 500 - First filter, 600 - Inert gas purging device, 610 - Inert gas pipeline, 700 - Second filter, 800 - Tail liquid collection device, 810 - Tail liquid collection tank, 820 - Valve. Detailed implementation manners

[0019] To make the objectives, technical solutions, and advantages of the present disclosure more apparent, exemplary embodiments according to the present disclosure will be described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments of the present disclosure. It should be understood that the present disclosure is not limited by the exemplary embodiments described herein.

[0020] In the olefin polymerization industry, the purification of olefin monomers is extremely crucial. Because impurities such as carbon dioxide, oxygen, and water in the monomers can cause the olefin polymerization catalyst to be poisoned, reduce its activity, interfere with the normal operation of the device, and also affect the quality of the polymerization product. Especially when preparing electronic or photovoltaic grade polyolefin resins, they will be converted into ash, affecting the electrical and optical properties of the product.

[0021] Currently, most related technologies adopt the method of passing olefin gas through a purification column system before the olefin gas enters the reaction device to remove impurities in the olefin gas. The purification column generally uses molecular sieves loaded with active components for chemical impurity removal, and often requires multiple purification columns to be connected in series. This method has many drawbacks. For example, the equipment occupies a large area, the impurity removal efficiency is low, the molecular sieve is easy to be saturated, and it needs to be replaced frequently or regenerated at high temperature, with cumbersome operation and high cost.

[0022] In view of the above problems, the embodiments of the present disclosure provide an olefin gas purification method, which can remove multiple impurities in the olefin gas at one time, simplifies the operation process, and reduces the cost. It solves the problems of the need for multiple purification columns to be connected in series, large equipment footprint, and slow impurity removal efficiency in the existing purification technology, avoids the disadvantages of easy saturation of the molecular sieve and difficult post-treatment after saturation, and significantly improves the efficiency and economy of olefin monomer purification.

[0023] Figure 1 The flowchart of the olefin gas purification method according to the embodiments of the present disclosure is shown and applied to the olefin gas purification system according to the embodiments of the present disclosure. As Figure 1 shown, the olefin gas purification method according to the embodiments of the present disclosure includes:

[0024] Step 101: Feed a liquid impurity removal agent into the purifier so that an impurity removal agent liquid level is formed at the bottom of the purifier.

[0025] Exemplarily, in the initial stage of system operation, liquid impurity remover can be fed into the purifier first. After the liquid impurity remover accumulates at the bottom of the purifier to form an impurity remover liquid level at the bottom of the purifier, then the bottom outlet of the purifier is connected to the impurity remover inlet of the impurity remover circulation pipeline, thereby realizing the circulation process. Specifically, to feed the liquid impurity remover into the purifier, it can be transported using the above-mentioned impurity remover circulation pipeline, or it can be fed into the purifier in other ways achievable in the existing technologies, which is not limited here. Before feeding the liquid impurity remover into the purifier using the above-mentioned impurity remover circulation pipeline, the impurity remover circulation pipeline can be connected to fresh impurity remover first, so as to provide a certain liquid level of fresh liquid impurity remover in the purifier at the initial stage of system operation. When the system operates stably, the connection between the impurity remover circulation pipeline and the fresh impurity remover can be disconnected, and the impurity remover circulation pipeline is used to continuously transport the impurity remover into the purifier.

[0026] Exemplarily, the pressure during the use of the above purifier is 0.1 MPa to 5 MPa, the temperature is -50 °C to 100 °C, and the liquid level height of the above impurity remover liquid level can be 30% to 40% of the height of the purifier.

[0027] Step 102: Use the impurity remover circulation pipeline to continuously transport the impurity remover in the purifier from the bottom outlet of the purifier to the top inlet of the purifier.

[0028] In specific implementation, when the system operates stably, the connection between the impurity remover circulation pipeline and the fresh impurity remover can be disconnected, and the impurity remover circulation pipeline is used to continuously transport the impurity remover in the purifier from the bottom outlet of the purifier to the top inlet of the purifier, thereby realizing the efficient recycling of the impurity remover and reducing the cost. In addition, during the circulation process, a unique flow field is formed by the impurity remover in the purifier, strengthening the contact with impurities.

[0029] Step 103: Feed the olefin gas into the purifier from the bottom inlet of the purifier, and the olefin gas is purified once through the impurity remover liquid level.

[0030] In specific implementation, the olefin gas to be purified can be transported to the bottom inlet of the purifier using the first olefin gas pipeline, and during the upward flow, it comes into full contact with the impurity remover liquid level for the first purification, so that impurities such as carbon dioxide, oxygen, and water in the olefin gas are adsorbed and removed by the impurity remover for the first time. The content of various impurities can be greatly reduced, and the olefin gas after the first purification is obtained.

[0031] Step 104: The olefin gas after the first purification rises in the purifier and comes into contact with the impurity remover entering from the top inlet during the rising process for the second purification.

[0032] During specific implementation, the olefin gas after primary purification rises in the purifier and enters the upper region above the liquid-phase impurity remover. During the rising process, it comes into countercurrent contact with the impurity remover entering from the top inlet of the purifier for secondary purification. At this time, impurities such as carbon dioxide, oxygen, and water in the olefin gas are basically adsorbed and removed by the impurity remover. Therefore, the content of various impurities in the olefin gas can be greatly reduced, thereby achieving the removal of multiple impurities in the olefin gas.

[0033] Step 105: The olefin gas after secondary purification is output from the purified olefin gas outlet to the gas-using area.

[0034] During specific implementation, the olefin gas after secondary purification flows out from the outlet at the position near the top of the purifier and enters the gas-using area. There is no need to connect multiple purification columns in series, avoiding the problems of large floor area of multiple purification columns and easy saturation of molecular sieves, which requires frequent replacement or high-temperature regeneration. Therefore, not only the operation process is simplified, but also the production cost is reduced.

[0035] For example, the impurity remover used in the embodiments of the present disclosure is an organoaluminum compound and / or an organozinc compound. The impurity remover can use the pure substance itself, or an impurity remover solution with a mass concentration of 2% - 95%, preferably 15% - 85%. If an impurity remover solution with a mass concentration of 2% - 95% is used, the solvent can be selected from one or several of toluene, xylene, o-xylene, p-xylene, n-heptane, and n-octane.

[0036] For the above-mentioned organoaluminum compound, it can include at least one of trialkylaluminum compounds, dialkylaluminum halide compounds, dialkylaluminum alkanol compounds, and dihydrodialkylaluminum compounds. For example: the organoaluminum compound can include at least one of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, dihydroisobutylaluminum, ethoxydiethylaluminum, chlorodiethylaluminum, and the like, but not limited thereto.

[0037] For the above-mentioned organozinc compound, it can include at least one of dialkylzinc compounds, dialkylaluminum halide compounds, dialkylaluminum alkanol compounds, and dihydrodialkylaluminum compounds. For example: the organozinc compound can include at least one of diethylzinc, di-n-propylzinc, di-n-butylzinc, dioctylzinc, diisobutylzinc, bis(3-butenyl)zinc, bis(3-methyl-3-butenyl)zinc, biscitronellylzinc, hydroisobutylaluminum, ethoxyethylaluminum, chloroethylaluminum, and the like, but not limited thereto.

[0038] In an alternative manner, the once-purified olefin gas rises in the purifier and contacts the impurity-removing agent entering from the top inlet during the rising process for secondary purification. Specifically, first, the impurity-removing agent entering from the top inlet of the purifier is atomized by an atomizer. Second, the atomized impurity-removing agent is evenly sprayed into the purifier. Then, the once-purified olefin gas rises in the purifier and contacts the atomized impurity-removing agent during the rising process for secondary purification.

[0039] During specific implementation, the impurity-removing agent entering from the top inlet of the purifier can enter the atomizer through the inlet of the atomizer and be atomized and then sprayed out. The atomized impurity-removing agent can be evenly dispersed in the purifier in the form of finer droplets. When the olefin gas comes out from the liquid level of the impurity-removing agent and enters the upper space of the purifier, the contact area between the impurity-removing agent and the olefin gas can be greatly increased. Compared with the non-atomized impurity-removing agent, the atomized impurity-removing agent in this state can react with the impurities in the olefin gas more quickly and fully, thus significantly improving the removal efficiency of the impurities and effectively enhancing the purification quality of the olefin gas. At the same time, the setting of the atomizer makes the distribution of the impurity-removing agent in the purifier more uniform, avoiding the situation of poor local impurity-removing effect, further ensuring the stability and consistency of the purification process, and providing a purer olefin gas raw material for the subsequent process.

[0040] In practical applications, the olefin gas can be greatly reduced in various impurity contents after being purified twice by the liquid level of the impurity-removing agent and the droplets of the impurity-removing agent. The impurity-removing agent is sprayed out after being atomized from the top of the purifier through an external circulation pipeline, and can sink to form a certain liquid level of the impurity-removing agent at the bottom of the purifier. Through such a circulating spraying process, the impurity-removing agent can be in full contact with the olefin gas to achieve an ideal impurity-removing effect.

[0041] In an achievable manner, the once-purified olefin gas rises in the purifier and contacts the atomized impurity-removing agent during the rising process for secondary purification. Specifically, first, the once-purified olefin gas rises in the purifier and passes through a first filter for the first filtration during the rising process. Second, the olefin gas after the first filtration continues to rise and contacts the atomized impurity-removing agent during the rising process for secondary purification.

[0042] During specific implementation, when the impurity-removing agent atomized by the atomizer reacts fully with the olefin gas, the mixed gas will first pass through the first filter during the downward flow. At this time, the first filter can effectively intercept the inorganic powder products generated by the reaction, prevent these inorganic powder products from entering the liquid-phase impurity-removing agent, avoid the pollution of the liquid-phase impurity-removing agent, and ensure the purity and continuous effectiveness of the liquid-phase impurity-removing agent.

[0043] It is understandable that the above-mentioned first filter can be assembled through a flange, and the first filter includes at least one of a metal filter screen, a ceramic filter screen, or a fiberglass filter screen.

[0044] In an implementable manner, the above method further includes: when replacing the first filter, using an inert gas purging device to convey inert gas into the purifier so that an inert atmosphere is maintained inside the purifier.

[0045] During specific implementation, when the first filter needs to be replaced, the inert gas purging device can first introduce inert gas into the purifier through an inert gas pipeline to purge the internal space of the purifier, preventing air from entering the purifier, thereby maintaining an inert atmosphere inside the purifier. This effectively avoids dangerous reactions that may occur between oxygen, moisture, etc. in the air and residual impurities or incompletely reacted impurity removal agents, greatly ensuring the safety of the replacement operation.

[0046] In an optional manner, the above-mentioned olefin gas after secondary purification is output from the purified olefin gas outlet to the gas-using area, specifically including: First, the olefin gas after secondary purification passes through a second filter for a second filtration before the purified olefin gas outlet, and then the olefin gas after the second filtration is output from the purified olefin gas outlet to the gas-using area.

[0047] During specific implementation, when the olefin gas entering the upper area of the purifier comes into contact with the atomized impurity removal agent, the impurities in the olefin gas fully react and combine with the impurity removal agent, but inevitably, part of the impurity removal agent remains in the olefin gas. At this time, the second filter can filter out the residual impurity removal agent liquid in the olefin gas and then discharge it to the gas-using area to ensure that the quality of the olefin gas entering the gas-using area meets the standards, providing a reliable raw material guarantee for subsequent industrial production.

[0048] It is understandable that the above-mentioned second filter can include at least one of a gas-liquid separation filter, a microporous metal filter, a fiber sintered felt filter, or a membrane filter.

[0049] In an example, the olefin gas purification method according to the embodiments of the present disclosure further includes: when the impurity removal agent tail liquid in the purifier needs to be replaced, discharging the impurity removal agent tail liquid to a tail liquid collection device through an impurity removal agent circulation pipeline.

[0050] In practical applications, when it is necessary to replace the impurity remover, the impurity remover in the purifier can be discharged into the tail liquid collection device through the impurity remover circulation pipeline. Thus, after collecting the tail liquid, the impurity remover can be replaced. Therefore, the impurity remover in the embodiments of the present disclosure can be regularly supplemented according to its consumption during the purification process. Compared with the traditional impurity remover treatment methods that require complex operations such as high-temperature regeneration, this system does not need to perform operations such as high-temperature regeneration, effectively simplifies the maintenance process of the impurity remover, reduces the system operation cost and operation complexity, and has significant technical advantages and application values.

[0051] In an optional manner, the olefin gas purification method in the embodiments of the present disclosure further includes: when it is necessary to replace the tail liquid of the impurity remover in the purifier, using a valve to connect the impurity remover circulation pipeline and the tail liquid collection tank, disconnecting the top inlet of the impurity remover circulation pipeline from the purifier. After the replacement of the tail liquid of the impurity remover in the purifier is completed, using the valve to disconnect the impurity remover circulation pipeline and the tail liquid collection tank, and connecting the impurity remover circulation pipeline to the top inlet of the purifier. It should be understood that this valve can be a three-way valve.

[0052] In practical applications, when it is necessary to replace the tail liquid of the impurity remover in the purifier, the passage between the three-way valve and the bottom outlet of the purifier and the tail liquid collection tank can be opened. After the replacement of the tail liquid of the impurity remover is completed, operate the valve again to disconnect the impurity remover circulation pipeline and the tail liquid collection tank, and connect the impurity remover circulation pipeline to the top inlet of the purifier. Then the purification system can quickly resume normal operation. The entire replacement process is simple to operate and can ensure that the tail liquid of the impurity remover is regularly discharged into the tail liquid collection tank.

[0053] Exemplarily, the olefin gas purification method in the embodiments of the present disclosure further includes: using a circulation pump to pump the impurity remover coming out from the bottom outlet of the purifier into the top inlet of the purifier, so that the impurity remover circulates in the impurity remover circulation pipeline.

[0054] In practical applications, setting a circulation pump on the impurity remover circulation pipeline can promote the directional flow of the impurity remover in the circulation loop formed by the purifier and the impurity remover circulation pipeline.

[0055] Figure 2 shows a schematic diagram of the olefin gas purification system provided by the embodiments of the present disclosure. As Figure 2As shown in the figure, the olefin gas purification system according to the embodiments of the present disclosure includes a purifier 100 and an impurity removal agent circulation pipeline 200. One end of the impurity removal agent circulation pipeline 200 is an impurity removal agent inlet, and the other end is an impurity removal agent outlet. The impurity removal agent outlet is communicated with the top inlet of the purifier 100, the bottom outlet of the purifier 100 is communicated with the impurity removal agent inlet, the bottom of the purifier 100 has an olefin gas inlet, the olefin gas inlet is communicated with the first olefin gas pipeline 110, a purified olefin gas outlet is formed at a position near the top of the purifier 100, and the purified olefin gas outlet is communicated with a gas-using area through the second olefin gas pipeline 120. A liquid-phase impurity removal agent 300 is formed at the bottom of the purifier 100.

[0056] It can be understood that at the initial stage of system operation, liquid impurity removal agent can be first fed into the purifier. After the liquid impurity removal agent accumulates at the bottom of the purifier 100 to form an impurity removal agent liquid level at the bottom of the purifier, the bottom outlet of the purifier 100 is then communicated with the impurity removal agent inlet of the impurity removal agent circulation pipeline 200, so as to realize the circulation process. Specifically, to feed the liquid impurity removal agent into the purifier, it can be transported by using the above-mentioned impurity removal agent circulation pipeline 200, or other methods that can be realized in the existing technologies can be used to feed the liquid impurity removal agent into the purifier, which is not limited here. Before feeding the liquid impurity removal agent into the purifier by using the above-mentioned impurity removal agent circulation pipeline 200, the impurity removal agent circulation pipeline 200 can be first communicated with fresh impurity removal agent, so as to provide a certain liquid level of fresh liquid-phase impurity removal agent 300 in the purifier at the initial stage of system operation. After the system operates stably, the impurity removal agent circulation pipeline 200 can be disconnected from the fresh impurity removal agent, and the impurity removal agent circulation pipeline 200 can be used to continuously transport the impurity removal agent into the purifier.

[0057] During specific implementation, since the above-mentioned impurity removal agent outlet is communicated with the top inlet of the purifier 100, and the bottom outlet of the purifier 100 is communicated with the impurity removal agent inlet, the impurity removal agent can enter from the top of the purifier 100, exit from the bottom of the purifier 100, and then be circulated into the purifier 100 through the impurity removal agent circulation pipeline, realizing the recycling of the impurity removal agent. Olefin gas enters from the olefin gas inlet at the bottom of the purifier 100, and fully contacts with the liquid-phase impurity removal agent 300 during the upward flow process, and then passes through the area above the liquid-phase impurity removal agent and counter-currently contacts with the impurity removal agent entering from the top inlet of the purifier. Impurities such as carbon dioxide, oxygen, and water in the olefin gas are adsorbed and removed by the impurity removal agent.

[0058] Exemplarily, the liquid level height of the above-mentioned liquid-phase impurity removal agent 300 can be 30% - 40% of the height of the purifier 100. The above-mentioned purified olefin gas outlet can be arranged on the top side wall of the purifier 100. The first olefin gas pipeline 110 contains crude olefin gas, and the second olefin gas pipeline 120 contains purified olefin gas.

[0059] In a realizable manner, such as Figure 2As shown, the olefin gas purification system of the embodiments of the present disclosure further includes an atomizer 400 disposed in the purifier 100. The top inlet of the purifier 100 is in communication with the liquid inlet of the atomizer 400. The atomizer 400 is configured to atomize the impurity removing agent entering through the top inlet of the purifier 100 and spray it into the purifier 100.

[0060] In specific implementation, the impurity removing agent entering through the top inlet of the purifier 100 can enter the atomizer 400 through the inlet of the atomizer 400, be atomized therein and then sprayed out. The atomized impurity removing agent can be evenly dispersed in the purifier 100 in the form of finer droplets.

[0061] Exemplarily, as Figure 2 shown, the olefin gas purification system of the embodiments of the present disclosure further includes a first filter 500 detachably installed in the purifier 100. The first filter 500 is located below the atomizer 400 and above the liquid level of the liquid-phase impurity removing agent.

[0062] It can be understood that the above-mentioned first filter 500 can be assembled by flanges.

[0063] In an alternative manner, as Figure 2 shown, the olefin gas purification system of the embodiments of the present disclosure further includes an inert gas purging device 600. The gas outlet of the inert gas purging device 600 is in communication with the purifier 100. The inert gas purging device 600 is configured to purge the purifier 100 to maintain an inert atmosphere therein when replacing the first filter 500. It should be understood that the inert gas purging device 600 is in communication with the purifier 100 through an inert gas pipeline 610.

[0064] In an example, as Figure 2 shown, the olefin gas purification system of the embodiments of the present disclosure further includes a second filter 700. The second filter 700 is disposed before the purified olefin gas outlet. The second filter 700 is configured to filter the residual impurity removing agent in the purified olefin gas.

[0065] Exemplarily, as Figure 2 shown, the olefin gas purification system of the embodiments of the present disclosure further includes a tail liquid collection device 800. The tail liquid collection device 800 is in communication with the impurity removing agent circulation pipeline 200.

[0066] Exemplarily, as Figure 2 shown, the tail liquid collection device of the embodiments of the present disclosure includes a tail liquid collection tank 810 and a valve 820. One end of the valve 820 is in communication with the impurity removing agent circulation pipeline 200, and the other end of the valve 820 is in communication with the tail liquid collection tank 810.

[0067] In practical applications, when it is necessary to drain the impurity remover in the purifier 100 into the tail liquid collection device 800 through the impurity remover circulation pipeline 200, the valve 820 can be opened to form a conduction path between the impurity remover circulation pipeline 200 and the tail liquid collection tank 810, thereby ensuring that the impurity remover can smoothly flow into the tail liquid collection tank 810 to complete the collection operation. When the impurity remover discharge operation is not required, closing the valve 820 can effectively prevent the backflow of the tail liquid collected in the tail liquid collection tank 810 and avoid external impurities and the like from entering the impurity remover circulation pipeline 200 through this communication path, thus ensuring the stable and reliable operation of the entire olefin gas purification system.

[0068] In an implementable manner, as Figure 2 shown, the impurity remover circulation pipeline 200 of the embodiment of the present disclosure is provided with a circulation pump 210, and the circulation pump 210 is used to pump the impurity remover coming out of the bottom outlet of the purifier 100 into the top inlet of the purifier 100.

[0069] For the olefin gas purification method of the embodiment of the present disclosure, first, the olefin gas enters from the bottom of the purifier and successively passes through the impurity remover at a certain liquid level and the atomized impurity remover droplets in the upper gas phase space to achieve two-stage purification, greatly reducing the content of various impurities in the gas. Secondly, the impurity remover is atomized and sprayed from the top through an external circulation pipeline and sinks to the bottom to form a circulating spraying process of the liquid level, ensuring sufficient contact between the impurity remover and the olefin gas, effectively improving the impurity removal efficiency, and achieving an ideal impurity removal effect. Furthermore, a filter screen is arranged in the middle of the purifier to timely collect the inorganic by-products generated by the reaction of the impurity remover and impurities, which is convenient to take out regularly and ensures the continuous and stable operation of the purification system. In addition, the tail liquid of the impurity remover after long-term reaction can be conveniently discharged through the tail liquid valve, further optimizing the entire purification process and providing a reliable and practical solution for the high-efficiency purification of olefin gas.

[0070] For the olefin gas purification method of the embodiment of the present disclosure, the water content in the purified olefin gas is less than 5.0 ppb (wt), the oxygen content is less than 5.0 ppb (V), the carbon dioxide content is less than 5.0 ppb (V), the alcoholate content is less than 5.0 ppb (wt), the total sulfur content is less than 2.0 ppb (wt), the arsenic content is less than 2.0 ppb (wt), and the chloride content is less than 2.0 ppb (wt).

[0071] Example 1

[0072] The olefin gas provided by the embodiment of the present disclosure is ethylene, the pressure in the purifier is 1.0 MPa, and the impurity remover used is triisobutylaluminum. Through the cyclic purification of the purifier of the present disclosure, the purification data of the ethylene gas are shown in Table 1.

[0073] Example 2

[0074] The olefin gas provided in the embodiments of the present disclosure is ethylene (the same as the ethylene used in Example 1). The pressure inside the purifier is 2.0 MPa, and the impurity remover used is diethylaluminum chloride. Through the cyclic purification of the purifier of the present disclosure, the purification data of the ethylene gas are shown in Table 1.

[0075] Example 3

[0076] The olefin gas provided in the embodiments of the present disclosure is propylene. The pressure inside the purifier is 0.4 MPa, and the impurity remover used is diethylzinc. Through the cyclic purification of the purifier of the present disclosure, the purification data of the propylene gas are shown in Table 2.

[0077] Example 4

[0078] The olefin gas provided in the embodiments of the present disclosure is propylene (the same as the propylene used in Example 3). The pressure inside the purifier is 2.0 MPa, and the impurity remover used is diisobutylaluminum hydride. Through the cyclic purification of the purifier of the present disclosure, the purification data of the ethylene gas are shown in Table 2.

[0079] Table 1 Comparison of ethylene purification effect data

[0080]

[0081] It can be seen from Table 1 that compared with the ethylene gas before purification, the contents of impurities such as oxygen, water, carbon dioxide, sulfur, and methanol in the ethylene of Example 1 and Example 2 have decreased significantly, reaching the ppb level.

[0082] Table 2 Comparison of propylene purification effect data

[0083]

[0084]

[0085] It can be seen from Table 2 that compared with the propylene gas before purification, the contents of impurities such as oxygen, water, carbon dioxide, sulfur, and methanol in the propylene of Example 3 and Example 4 have decreased significantly, reaching the ppb level.

[0086] In summary, it can be known that the olefin gas purification system of the embodiments of the present disclosure can greatly reduce the content of impurities in the olefin gas to the ppb level. Moreover, the device is simple and does not require a high-temperature regeneration step, which not only greatly simplifies the operation process, reduces the equipment investment and maintenance costs, but also significantly improves the stability and reliability of the purification process.

[0087] The basic principles of the present disclosure have been described in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are only examples and not limitations. It cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present disclosure. Additionally, the specific details disclosed above are only for illustrative and facilitating understanding purposes, rather than limitations. These details do not limit the present disclosure to necessarily adopt the above specific details for implementation.

[0088] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended terms, meaning "including but not limited to", and can be used interchangeably with each other. The word "or" and "and" used herein refer to the word "and / or", and can be used interchangeably with it, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0089] In addition, as used herein, the "or" used in the listing of items starting with "at least one" indicates a disjunctive listing. So, for example, the listing of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the term "exemplary" does not mean that the described examples are preferred or better than other examples.

[0090] It should also be noted that in the systems and methods of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present disclosure.

[0091] Various changes, substitutions, and alterations to the technologies described herein can be made without departing from the teachings of the technology defined by the appended claims. Additionally, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and acts described above. Current or later-developed processes, machines, manufactures, compositions of events, means, methods, or acts that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or acts within their scope.

[0092] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0093] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although several example aspects and embodiments have been discussed above, those skilled in the art will recognize some of their variations, modifications, alterations, additions, and subcombinations.

Claims

1. A method for purifying olefin gas, characterized in that: The following steps are involved: Adding a liquid impurity remover into the purifier so that a liquid level of the impurity remover is formed at the bottom of the purifier; The impurity remover in the purifier is continuously transported from the bottom outlet of the purifier to the top inlet of the purifier by using an impurity remover circulation pipeline; The olefin gas is fed into the purifier from the bottom inlet of the purifier, and the olefin gas is purified once by passing through the impurity remover liquid surface; The olefin gas after the primary purification rises in the purifier, and during the rising process, it contacts with the impurity remover coming from the top inlet, and undergoes secondary purification; The olefin gas after secondary purification is output from the purified olefin gas outlet to the gas using area.

2. The olefin gas purification method according to claim 1, characterized in that: The olefin gas after the primary purification rises in the purifier, and contacts with the impurity remover coming from the top inlet during the rising process, and performs secondary purification, further comprising: Atomizing the impurity remover entering the top inlet of the purifier by using an atomizer; Evenly spraying the atomized impurity remover into the purifier; The olefin gas after the primary purification rises in the purifier, and contacts with the atomized impurity remover during the rising process, and undergoes secondary purification.

3. The olefin gas purification method according to claim 2, characterized in that: The olefin gas after the primary purification rises in the purifier, contacts with the atomized impurity remover during the rising process, and performs secondary purification, further comprising: The olefin gas after the primary purification rises in the purifier and is filtered for the first time through the first filter during the rising process; The olefin gas after the first filtration continues to rise, and during the rising process it comes into contact with the atomized impurity remover for secondary purification.

4. The olefin gas purification method according to claim 3, characterized in that: The method further comprises: When the first filter is replaced, an inert gas purge device is used to deliver inert gas into the purifier so as to maintain an inert atmosphere in the purifier.

5. The olefin gas purification method according to claim 1, characterized in that: The olefin gas after secondary purification is output from the purified olefin gas outlet to the gas use area, further comprising: The olefin gas after secondary purification is filtered for the second time through a second filter before the outlet of the purified olefin gas; The olefin gas after the second filtration is output from the purified olefin gas outlet to the gas using area.

6. The olefin gas purification method according to claim 1, characterized in that: The method further comprises: When the impurity-removing agent tail liquid in the purifier needs to be replaced, the impurity-removing agent tail liquid is discharged to the tail liquid collecting device through the impurity-removing agent circulation pipeline.

7. The olefin gas purification method according to claim 6, characterized in that: The method further comprises: When the impurity remover tail liquid in the purifier needs to be replaced, the impurity remover circulation pipeline and the tail liquid collecting tank are connected by a valve, and the impurity remover circulation pipeline and the top inlet of the purifier are disconnected; After the impurity remover tail liquid in the purifier is replaced, the impurity remover circulation pipeline and the tail liquid collecting tank are disconnected by using a valve, and the impurity remover circulation pipeline is connected to the top inlet of the purifier.

8. The olefin gas purification method according to claim 1, characterized in that: The method further comprises: The impurity remover coming out of the bottom outlet of the purifier is pumped into the top inlet of the purifier by a circulation pump, so that the impurity remover circulates in the impurity remover circulation pipeline.

9. The olefin gas purification method according to any one of claims 1 to 8, characterized in that: The pressure of the purifier when in use is 0.1MPa to 5MPa, and the temperature is -50°C to 100°C.

10. The olefin gas purification method according to any one of claims 1 to 8, characterized in that: The impurity remover includes an organic aluminum compound and / or an organic zinc compound.

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