Propylene refining system

Abstract

The present invention provides a propylene refining system, which comprises: a green oil remover, which is provided with a feed port and a discharge port, the feed port is connected with a raw material propylene feed line, and the green oil remover is used for separating green oil in the raw material propylene; the middle part of the light component stripping tower is provided with a first inlet, the bottom of the light component stripping tower is provided with a first outlet, the first inlet is communicated with the discharge port, and the light component stripping tower is used for removing light component impurities in the raw material propylene; a second inlet is formed in the bottom of the drying tower, a second outlet is formed in the top of the drying tower, the second inlet is communicated with the first outlet, and the drying tower is used for drying the raw material propylene subjected to impurity removal. Through the technical scheme provided by the invention, the problem that green oil in the raw material propylene is difficult to remove in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of propylene refining, and in particular to a propylene refining system. Background Art

[0002] At present, the main source of raw material propylene used in the domestic petrochemical industry is the catalytic reforming and cracking process of naphtha. This process is an effective technology to reduce reaction temperature, reduce coking, increase ethylene yield and save energy and reduce consumption. Its good raw material adaptability and high low-carbon olefin yield in the reaction are widely favored. However, the side reaction of the hydrogenation reaction in this process will form oligomers containing unsaturated hydrocarbon components. This oily oligomer is both inevitable and difficult to be completely separated from propylene. Once these substances come into contact with the propylene polymerization catalyst, they will be preferentially selected to coordinate to the active center of the catalyst, resulting in catalyst deactivation.

[0003] At present, the refining process of raw material propylene is still in the simple filtration stage. It is difficult to completely separate the oily oligomers from propylene, which directly affects the polymerization reaction activity and the quality indicators of the final product. Summary of the invention

[0004] The invention provides a propylene refining system to solve the problem that green oil in raw material propylene is difficult to remove in the prior art.

[0005] The invention provides a propylene refining system, which comprises: a green oil remover, wherein a feed port and a discharge port are arranged on the green oil remover, the feed port is connected to a raw material propylene feed line, and the green oil remover is used to separate green oil in the raw material propylene; a light component stripping tower, wherein a first inlet is provided in the middle of the light component stripping tower, a first outlet is provided at the bottom of the light component stripping tower, the first inlet is communicated with the discharge port, and the light component stripping tower is used to remove light component impurities in the raw material propylene; and a drying tower, wherein a second inlet is provided at the bottom of the drying tower, a second outlet is provided at the top of the drying tower, the second inlet is communicated with the first outlet, and the drying tower is used to dry the raw material propylene after impurities are removed.

[0006] Furthermore, the green oil remover includes a shell, and the feed port and the discharge port are both arranged on the shell. The shell has a flow channel inside, and the flow channel is connected to the feed port and the discharge port respectively. The green oil remover also includes a multi-stage adsorption structure, and the multi-stage adsorption structure is located in the flow channel. The green oil adsorption particle size of the multi-stage adsorption structure gradually decreases along the flow direction of the flow channel.

[0007] Furthermore, the propylene refining system also includes a propylene feed line, one end of the propylene feed line is connected to the raw material propylene feed line, and the other end of the propylene feed line is connected to the feed port. A first control valve is arranged on the propylene feed line, and the first control valve is used to control the flow in the propylene feed line. A liquid level meter is connected to the light component stripping tower, and the liquid level meter is used to detect the liquid level in the light component stripping tower. The liquid level meter cooperates with the first control valve to adjust the liquid level in the light component stripping tower.

[0008] Furthermore, an exhaust gas pipeline is arranged at the top of the light component stripping tower, and a second control valve and a pressure gauge are arranged in sequence on the exhaust gas pipeline, the second control valve is used to control the flow in the exhaust gas pipeline, and the pressure gauge is used to detect the pressure value in the exhaust gas pipeline, the light component stripping tower also includes a reboiler, the reboiler is used to provide high-temperature steam to the light component stripping tower, the reboiler is connected to an inlet pipeline and an outlet pipeline, a fifth control valve is arranged on the inlet pipeline, and the pressure gauge, the fifth control valve and the second control valve cooperate with each other to adjust the pressure in the light component stripping tower.

[0009] Furthermore, the multi-stage adsorption structure includes: a first separation chamber, the first separation chamber is connected to the feed port to adsorb green oil with a particle size of 20 microns to 50 microns in the raw material propylene; a second separation chamber is sequentially connected to the flow direction of the first separation chamber to adsorb green oil with a particle size of 10 microns to 20 microns in the raw material propylene; a third separation chamber, one side of the third separation chamber is connected to the second separation chamber, and the other side of the third separation chamber is connected to the discharge port to adsorb green oil with a particle size of 1 micron to 10 microns in the raw material propylene.

[0010] Furthermore, the propylene refining system also includes a nitrogen pipeline and a steam pipeline. The nitrogen pipeline is used to introduce nitrogen into the flow channel. The steam pipeline is connected to the nitrogen pipeline. A third control valve is arranged on the steam pipeline.

[0011] Furthermore, the propylene refining system has two green oil removers, which are arranged in parallel with the light component stripping tower, and the propylene feed line, nitrogen pipeline and steam pipeline are respectively connected to the two green oil removers.

[0012] Furthermore, the propylene refining system further comprises a bypass, one end of the bypass is connected to the propylene feed line, the other end of the bypass is connected to the first inlet, and a fourth control valve is arranged on the bypass.

[0013] Furthermore, the drying tower has a drying chamber and an adsorption chamber arranged in sequence, the drying chamber is connected to the second inlet, the adsorption chamber is connected to the second outlet, the drying chamber is filled with a desiccant, and the adsorption chamber is filled with an ion exchange molecular sieve adsorbent.

[0014] Furthermore, a material return pipeline is provided at the bottom of the green oil remover, and the material return pipeline is used to discharge the raw material propylene in the flow channel.

[0015] By applying the technical solution of the present invention, the green oil remover can remove the green oil in the raw material propylene, wherein the green oil is an oligomer of unsaturated hydrocarbon components. The light component stripping tower can remove light component impurities in the raw material propylene, such as methanol, alkanes and olefins. The drying tower can dry the raw material propylene after impurities are removed. Through the above-mentioned configuration, the green oil remover, the light component stripping tower and the drying tower cooperate with each other, and no further fractionation or catalyst high-temperature calcination regeneration steps are required, which not only saves energy costs and simplifies the distillation steps, but also avoids the deactivation or even poisoning of the propylene polymerization catalyst due to impure raw materials, thereby ensuring the activity of the catalyst in the polymerization reaction and the quality of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 The structural schematic diagram of the propylene refining system provided by the present invention is shown;

[0018] Figure 2 The schematic diagram of the structure of the green oil remover provided by the present invention is shown.

[0019] The above drawings include the following reference numerals:

[0020] 10. Green oil remover;

[0021] 101, feed inlet;

[0022] 102. Discharge port;

[0023] 103. A first separation chamber;

[0024] 104. A second separation chamber;

[0025] 105. The third separation chamber;

[0026] 11. Shell;

[0027] 12. Guide plate;

[0028] 20. Light component stripping tower;

[0029] 21. Liquid level gauge;

[0030] 22. Reboiler;

[0031] 221, inlet pipeline;

[0032] 222. Export pipeline;

[0033] 223. Flow meter;

[0034] 224, fifth control valve;

[0035] 201, first entrance;

[0036] 202, first exit;

[0037] 30. Drying tower;

[0038] 301, second entrance;

[0039] 302, second exit;

[0040] 303, drying chamber;

[0041] 304, adsorption chamber;

[0042] 40. Propylene feed line;

[0043] 41. First control valve;

[0044] 50. Exhaust gas pipeline;

[0045] 51. Second control valve;

[0046] 52. Pressure gauge;

[0047] 60. Nitrogen pipeline;

[0048] 70. Steam pipeline;

[0049] 71. The third control valve;

[0050] 80. Bypass;

[0051] 81. Fourth control valve;

[0052] 90. Material return pipeline. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] In the present application, green oil specifically comprises trace amounts of amines, acrylic acid and other compounds as well as heavy components such as macromolecular alkanes and other substances.

[0055] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a propylene refining system, which includes: a green oil remover 10, a light component stripping tower 20 and a drying tower 30. Among them, the green oil remover 10 is provided with a feed port 101 and a discharge port 102, the feed port 101 is connected to the raw material propylene feed line, and the green oil remover 10 is used to separate the green oil in the raw material propylene. The middle part of the light component stripping tower 20 has a first inlet 201, the bottom of the light component stripping tower 20 has a first outlet 202, the first inlet 201 is connected to the discharge port 102, and the light component stripping tower 20 is used to remove light component impurities in the raw material propylene. The bottom of the drying tower 30 has a second inlet 301, the top of the drying tower 30 has a second outlet 302, the second inlet 301 is connected to the first outlet 202, and the drying tower 30 is used to dry the raw material propylene after impurities are removed.

[0056] By applying the technical solution of the present invention, the green oil remover 10 can remove the green oil in the raw material propylene, wherein the green oil is a oligomer of unsaturated hydrocarbon components. The light component stripping tower 20 can remove light component impurities in the raw material propylene, such as methanol, alkanes and olefins. The drying tower 30 can dry the raw material propylene after impurities are removed. Through the above-mentioned arrangement, the green oil remover, the light component stripping tower and the drying tower cooperate with each other, and no further fractionation or high-temperature calcination regeneration step of the catalyst is required, which not only saves energy costs and simplifies the distillation step, but also avoids the deactivation or even poisoning of the propylene polymerization catalyst due to impure raw materials, thereby ensuring the activity of the catalyst in the polymerization reaction and the quality of the final product.

[0057] Specifically, the green oil remover 10 includes a shell 11, a feed port 101 and a discharge port 102 are both arranged on the shell 11, a circulation channel is provided in the shell 11, and the circulation channel is respectively connected with the feed port 101 and the discharge port 102, and the green oil remover 10 also includes a multi-stage adsorption structure, the multi-stage adsorption structure is located in the circulation channel, and the green oil adsorption particle size of the multi-stage adsorption structure gradually decreases along the circulation direction of the circulation channel. Through the above arrangement, the multi-stage adsorption structure makes the green oil removal more thorough, and there is no need to remove the green oil again in the subsequent process, thereby improving the stability and efficiency of the overall refining system. And through the layered design of the multi-stage adsorption structure, green oils of different particle sizes can be effectively treated, reducing the deposition of green oil in subsequent equipment, extending the service life of the entire system, and reducing maintenance costs.

[0058] Further, the propylene refining system further comprises a propylene feed line 40, one end of which is connected to the boundary propylene feed main pipe, and the other end of which is connected to the feed port 101. A first control valve 41 is provided on the propylene feed line 40, and the first control valve 41 is used to control the flow rate in the propylene feed line 40. A liquid level meter 21 is connected to the light component stripping tower 20, and the liquid level meter 21 is used to detect the liquid level in the light component stripping tower 20. The liquid level meter 21 cooperates with the first control valve 41 to adjust the liquid level in the light component stripping tower 20. The above arrangement can provide accurate flow and liquid level control, avoid equipment damage and production interruption caused by pressure fluctuations, ensure the smooth operation of the system, reduce production accidents caused by equipment fragmentation or explosion due to pressure fluctuations, and improve production safety.

[0059] Specifically, when the liquid level meter 21 detects that the liquid level in the light component stripping tower 20 is high, the opening of the first control valve 41 is reduced, and the flow rate of the raw material propylene entering the light component stripping tower 20 is reduced; when the liquid level meter 21 detects that the liquid level in the light component stripping tower 20 is low, the opening of the first control valve 41 is increased, and the flow rate of the raw material propylene entering the light component stripping tower 20 is increased to ensure that the liquid level in the light component stripping tower 20 always remains stable.

[0060] In the present application, a discharge gas pipeline 50 is provided at the top of the light component stripping tower 20, and a second control valve 51 is sequentially provided on the discharge gas pipeline 50, and the second control valve 51 is used to control the flow rate in the discharge gas pipeline 50, and the pressure gauge 52 is used to detect the pressure value in the discharge gas pipeline 50. The light component stripping tower 20 also includes a reboiler 22, and the reboiler 22 is used to provide high-temperature steam to the light component stripping tower 20 to heat the raw material propylene, so that the light component substances such as hydrogen and oxygen in the raw material propylene evaporate and are discharged from the discharge gas pipeline 50. The reboiler 22 is connected to an inlet pipeline 221 and an outlet pipeline 222, and a flow meter 223 and a fifth control valve 224 are sequentially provided on the inlet pipeline 221, and the pressure gauge 52, the fifth control valve 224 and the second control valve 51 cooperate with each other to adjust the pressure in the light component stripping tower 20. The exhaust gas pipeline 50 is connected to the cracking device, and a flow meter 223 is also provided on the inlet pipeline 221, and the flow meter 223 is used to detect the flow in the inlet pipeline 221. Through the above-mentioned pressure regulation mechanism, it is possible to effectively avoid the pressure of the light component stripping tower 20 being too high or too low, ensuring the efficiency and stability of the stripping process. At the same time, it is also possible to optimize the stripping process, effectively avoiding the waste of raw materials caused by excessive pressure and the stripping efficiency affected by too low pressure. Figure 1 The dotted pipelines in the figure represent the cascade control formed by the liquid level meter 21 and the first control valve 41 , and the cascade control formed by the pressure gauge 52 , the flow meter 223 , the fifth control valve 224 and the second control valve 51 .

[0061] Specifically, the first control valve 41 and the second control valve 51 are configured as control valves, which can be controlled on-site or remotely.

[0062] Specifically, when the pressure gauge 52 detects that the pressure value in the exhaust gas pipeline 50 is large, that is, the pressure value in the light component stripping tower 20 is large, the opening of the second control valve 51 is increased to accelerate the discharge of the fluid in the exhaust gas pipeline 50, and the opening of the fifth control valve 224 is reduced to reduce the flow rate of high-temperature steam entering the light component stripping tower 20; when the pressure gauge 52 detects that the pressure in the light component stripping tower 20 is small, the opening of the fifth control valve 224 is increased to increase the flow rate of high-temperature steam entering the light component stripping tower 20, so that the raw material propylene is gasified and pressurized. In the present application, the raw material propylene is liquid propylene.

[0063] like Figure 2 As shown, the multi-stage adsorption structure includes: a first separation chamber 103, a second separation chamber 104 and a third separation chamber 105. Among them, the first separation chamber 103 is connected to the feed port 101 to adsorb the green oil with a particle size of 20 microns to 50 microns in the raw material propylene. The second separation chamber 104 is sequentially connected to the first separation chamber 103 in the flow direction to adsorb the green oil with a particle size of 10 microns to 20 microns in the raw material propylene. One side of the third separation chamber 105 is connected to the second separation chamber 104, and the other side of the third separation chamber 105 is connected to the discharge port 102 to adsorb the green oil with a particle size of 1 micron to 10 microns in the raw material propylene. In this way, green oils of different particle sizes can be removed in a targeted manner, thereby improving the accuracy and effect of green oil removal. Among them, a guide plate 12 is also provided at the material inlet of each chamber, which can adjust the flow direction and flow rate of the material.

[0064] Specifically, the first separation chamber 103 is provided with a gel-grafted high molecular silicone surfactant, which has the functions of filtering, preliminary demulsification, and condensation of dispersed droplets, and can remove green oil with a particle size of 20 microns to 50 microns in the raw material propylene; the second separation chamber 104 is provided with a gel-grafted PA type surfactant, which has a surface property of both amphiphilic and amphiphilic, and can remove green oil with a particle size of 10 microns to 20 microns in the raw material propylene; the third separation chamber 105 is provided with a gel-grafted F4 type surfactant, which has a monophilic and monophobic surface property, and can remove green oil with a particle size of 20 microns to 50 microns in the raw material propylene.

[0065] Furthermore, the propylene refining system also includes a nitrogen pipeline 60 and a steam pipeline 70. The nitrogen pipeline 60 is used to introduce nitrogen into the flow channel. The steam pipeline 70 is connected to the nitrogen pipeline 60. The steam pipeline 70 is provided with a third control valve 71. Through the above arrangement, the nitrogen in the nitrogen pipeline 60 and the steam in the steam pipeline 70 can be mixed into wet nitrogen and enter the green oil remover 10 to desorb the green oil in the above-mentioned active agent. Then, the third control valve 71 is closed, and dry nitrogen is introduced into the green oil remover 10 to dry the flow channel and complete the regeneration of the green oil remover 10. Among them, one end of the nitrogen pipeline 60 has three branch pipes, and the three branch pipes are respectively connected to the first separation chamber 103, the second separation chamber 104 and the third separation chamber 105 in a one-to-one correspondence.

[0066] Preferably, the propylene refining system has two green oil removers 10, which are arranged in parallel with the light component stripping tower 20, and the propylene feed line 40, the nitrogen pipeline 60 and the steam pipeline 70 are respectively connected to the two green oil removers 10. In this way, the two green oil removers 10 can be switched in actual production, one is on and the other is on standby. When one green oil remover 10 is performing adsorption operation, the other green oil remover 10 is performing activation and regeneration treatment. The green oil removers arranged in parallel can improve the processing capacity and flexibility of the system, ensure the needs of continuous production, and at the same time reduce the operating pressure of a single green oil remover 10, thereby extending the service life of the equipment.

[0067] The propylene refining system further includes a bypass 80, one end of which is connected to the propylene feed line 40, and the other end of which is connected to the first inlet 201. A fourth control valve 81 is provided on the bypass 80. By providing the bypass 80, when both green oil removers 10 are blocked or damaged, the fourth control valve 81 can be opened, so that the raw propylene can directly enter the light component stripping tower 20 through the bypass 80 for subsequent refining operations, thereby ensuring the continuity of the entire refining process. The third control valve 71 and the fourth control valve 81 are both gate valves, which are manually controlled by on-site staff.

[0068] Furthermore, the drying tower 30 has a drying chamber 303 and an adsorption chamber 304 arranged in sequence, the drying chamber 303 is connected to the second inlet 301, and the adsorption chamber 304 is connected to the second outlet 302. The drying chamber 303 is filled with a desiccant, and the adsorption chamber 304 is filled with an ion exchange molecular sieve adsorbent. After the raw material propylene is filtered by the de-green oil remover 10, the polar oxygen-containing compounds of low-carbon hydrocarbons such as alcohols, ethers, aldehydes, ketones and trace water that remain will occupy the active sites of the active substance TiCl4 of the polypropylene catalyst, resulting in partial deactivation of the catalyst. Trace water will react with the co-catalyst TEA, causing its activity to decrease and the catalyst unit consumption to increase. Through the above-mentioned arrangement, the present application can adsorb and remove the above-mentioned substances, further improve the purity and quality of propylene, and provide a safer and more reliable raw material for subsequent production. Among them, the filling volume of the desiccant and the ion exchange molecular sieve adsorbent in the light component stripping tower 20 each accounts for 50%, both of which are 43m 3 .

[0069] Specifically, the oxygen-containing compound adsorbent may be NaX, NaY molecular sieve adsorbent, etc. After entering the drying tower 30 and being adsorbed by the ion exchange molecular sieve adsorbent, the oxygen-containing compound concentration measured is ≤1ppm, and the dynamic penetration adsorption capacity thereof is ≥40mg / g.

[0070] In this embodiment, the propylene refining system has two light component stripping towers 20, so that the two light component stripping towers 20 can be switched in actual production, one is on and the other is on standby, and when one light component stripping tower 20 is performing adsorption operation, the other light component stripping tower 20 is performing activation and regeneration treatment. The light component stripping towers 20 arranged in parallel can improve the processing capacity and flexibility of the system, ensure the needs of continuous production, and at the same time reduce the operating pressure of a single light component stripping tower 20, thereby extending the service life of the equipment.

[0071] In the present application, a material withdrawal pipeline 90 is also provided at the bottom of the green oil remover 10, and the material withdrawal pipeline 90 is used to discharge the raw material propylene in the circulation channel. When the green oil remover 10 is regenerated, the raw material propylene in the green oil remover 10 needs to be discharged through the material withdrawal pipeline 90, and then wet nitrogen is introduced to regenerate the active agent, and the subsequent substances can also be discharged from the green oil remover 10 through the material withdrawal pipeline 90. Among them, the end of the material withdrawal pipeline 90 is connected to three bypasses, and the three bypasses are connected to the first separation chamber 103, the second separation chamber 104 and the third separation chamber 105 one by one.

[0072] The propylene refining system provided by the present application can integrate precise filtration, effective adsorption, drying and deoxygenation. The purity of the refined propylene is improved and can be directly put into production without further distillation or high-temperature calcination and regeneration of the catalyst. While saving energy costs, it can fundamentally solve the problem of deactivation or even poisoning of propylene polymerization catalysts due to impure raw materials.

[0073] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0074] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0075] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the system or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0076] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0077] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A propylene refining system, characterized in that: The propylene refining system comprises: A green oil remover (10), wherein the green oil remover (10) is provided with a feed port (101) and a discharge port (102), wherein the feed port (101) is connected to a feed line of raw material propylene, and the green oil remover (10) is used to separate green oil from the raw material propylene; A light component stripping tower (20), wherein the middle portion of the light component stripping tower (20) has a first inlet (201), the bottom portion of the light component stripping tower (20) has a first outlet (202), the first inlet (201) is connected to the discharge port (102), and the light component stripping tower (20) is used to remove light component impurities in the raw material propylene; A drying tower (30), wherein the bottom of the drying tower (30) has a second inlet (301), the top of the drying tower (30) has a second outlet (302), the second inlet (301) is connected to the first outlet (202), and the drying tower (30) is used to dry the raw material propylene after impurities are removed.

2. The propylene refining system according to claim 1, characterized in that: The green oil remover (10) comprises a shell (11), the feed port (101) and the discharge port (102) are both arranged on the shell (11), a circulation channel is provided in the shell (11), the circulation channel is communicated with the feed port (101) and the discharge port (102) respectively, and the green oil remover (10) further comprises a multi-stage adsorption structure, the multi-stage adsorption structure is located in the circulation channel, and the green oil adsorption particle size of the multi-stage adsorption structure gradually decreases along the circulation direction of the circulation channel.

3. The propylene refining system according to claim 2, characterized in that: The propylene refining system further comprises a propylene feed line (40), one end of the propylene feed line (40) is connected to the raw material propylene feed line, and the other end of the propylene feed line (40) is connected to the feed port (101). The propylene feed line (40) is provided with a first control valve (41), and the first control valve (41) is used to control the flow rate in the propylene feed line (40). The light component stripping tower (20) is connected to a liquid level meter (21), and the liquid level meter (21) is used to detect the liquid level in the light component stripping tower (20). The liquid level meter (21) cooperates with the first control valve (41) to adjust the liquid level in the light component stripping tower (20).

4. The propylene refining system according to claim 3, characterized in that: The top of the light component stripping tower (20) is provided with an exhaust gas pipeline (50), and the exhaust gas pipeline (50) is provided with a second control valve (51) and a pressure gauge (52) in sequence, the second control valve (51) is used to control the flow rate in the exhaust gas pipeline (50), and the pressure gauge (52) is used to detect the pressure value in the exhaust gas pipeline (50). The light component stripping tower (20) also includes a reboiler (22), and the reboiler (22) is used to provide high-temperature steam to the light component stripping tower (20). The reboiler (22) is connected to an inlet pipeline (221) and an outlet pipeline (222), and a fifth control valve (224) is provided on the inlet pipeline (221). The pressure gauge (52), the fifth control valve (224) and the second control valve (51) cooperate with each other to adjust the pressure in the light component stripping tower (20).

5. The propylene refining system according to claim 2, characterized in that: The multi-stage adsorption structure comprises: A first separation chamber (103), the first separation chamber (103) being in communication with the feed port (101) for adsorbing green oil with a particle size of 20 microns to 50 microns in the raw material propylene; The second separation chamber (104) is connected in sequence with the first separation chamber (103) in the flow direction to adsorb the green oil with a particle size of 10 microns to 20 microns in the raw material propylene; A third separation chamber (105), one side of the third separation chamber (105) is connected to the second separation chamber (104), and the other side of the third separation chamber (105) is connected to the discharge port (102), so as to adsorb the green oil with a particle size of 1 micron to 10 microns in the raw material propylene.

6. The propylene refining system according to claim 3, characterized in that: The propylene refining system further comprises a nitrogen pipeline (60) and a steam pipeline (70). The nitrogen pipeline (60) is used to introduce nitrogen into the flow channel. The steam pipeline (70) is connected to the nitrogen pipeline (60). A third control valve (71) is arranged on the steam pipeline (70).

7. The propylene refining system according to claim 6, characterized in that: The propylene refining system comprises two green oil removers (10), the two green oil removers (10) are arranged in parallel with the light component stripping tower (20), and the propylene feed line (40), the nitrogen pipeline (60) and the steam pipeline (70) are respectively connected to the two green oil removers (10).

8. The propylene refining system according to claim 7, characterized in that: The propylene refining system further comprises a bypass (80), one end of the bypass (80) is connected to the propylene feed line (40), and the other end of the bypass (80) is connected to the first inlet (201), and a fourth control valve (81) is provided on the bypass (80).

9. The propylene refining system according to claim 1, characterized in that: The drying tower (30) has a drying chamber (303) and an adsorption chamber (304) arranged in sequence, the drying chamber (303) is connected to the second inlet (301), the adsorption chamber (304) is connected to the second outlet (302), the drying chamber (303) is filled with a desiccant, and the adsorption chamber (304) is filled with an ion exchange molecular sieve adsorbent.

10. The propylene refining system according to claim 6, characterized in that: A material withdrawal pipeline (90) is also provided at the bottom of the green oil remover (10), and the material withdrawal pipeline (90) is used to discharge the raw material propylene in the circulation channel.

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