An apparatus and method for separating ethane and ethylene

Abstract

The present application relates to the technical field of ethane ethylene separation, in particular to a device and method for realizing ethane ethylene separation. In order to solve the problem of low recovery rate of ethylene when ethane selective porous material is used to realize ethane ethylene separation, a new device for realizing ethane ethylene separation is provided, which comprises a compressor, an air inlet buffer tank, an ethylene product flow control valve, an ethylene product gas buffer tank, an ethane product gas buffer tank, a vacuum pump, a plurality of adsorption towers filled with ethane selective porous material, a plurality of product gas control valves, a plurality of pressure equalization control valves, a plurality of raw material gas control valves, a plurality of ethane displacement control valves and a plurality of vacuum control valves. The device can not only realize efficient separation of ethane ethylene, relieve the pressure of ethylene resource demand, but also realize continuous treatment of ethane ethylene mixed gas and improve the treatment efficiency.

Description

Technical Field

[0001] This invention relates to the field of ethane-ethylene separation technology, specifically to an apparatus and method for separating ethane and ethylene. Background Technology

[0002] Ethylene is an important basic raw material for petrochemicals, and its output is a key indicator of a country's petrochemical development level. In traditional ethylene production processes such as steam cracking, catalytic cracking, and ethane dehydrogenation, approximately 5-15% ethane impurities are often present.

[0003] To obtain polymer-grade ethylene, cryogenic distillation is commonly used, utilizing the difference in boiling points between ethane and ethylene to achieve separation and thus recover ethylene. However, this method requires high pressure and low temperature conditions and multiple trays to achieve efficient separation, resulting in significant energy consumption while maintaining high separation efficiency. Existing technologies also employ ethane-selective porous materials for ethane-ethylene separation, but these methods are often limited by the weak ethane adsorption capacity and low selectivity of these materials, thus hindering improvements in ethylene recovery rates. Summary of the Invention

[0004] In order to solve the problem of low ethylene recovery rate when using ethane-selective porous materials to separate ethane and ethylene, this invention provides a new apparatus and method for achieving ethane-ethylene separation.

[0005] This invention is achieved using the following technical solution:

[0006] An apparatus for separating ethane and ethylene includes a compressor, an inlet buffer tank, an ethylene product flow control valve, an ethylene product gas buffer tank, an ethane product gas buffer tank, a vacuum pump, multiple adsorption towers each filled with an ethane-selective porous material, multiple product gas control valves, multiple pressure equalization control valves, multiple feed gas control valves, multiple ethane displacement control valves, and multiple vacuum control valves. One end of the compressor is used to introduce an ethane-ethylene mixture, and the other end of the compressor is connected to one end of the inlet buffer tank. The other end of the inlet buffer tank is connected to the inlet of each of the multiple adsorption towers via the multiple feed gas control valves. One end of each of the multiple vacuum control valves is connected to the inlet of the multiple adsorption towers, and the other end of each of the multiple vacuum control valves is connected to the inlet of the vacuum pump. The pump's outlet is connected to the inlet of the ethane product gas buffer tank. One end of each of the multiple ethane displacement control valves is connected to the inlet of each of the multiple adsorption towers, and the other end of each of the multiple ethane displacement control valves is connected to the displacement end of the ethane product gas buffer tank. The outlet of the ethane product gas buffer tank is used to output ethane product gas. One end of each of the multiple pressure equalization control valves is connected to the outlet of each of the multiple adsorption towers, and the other end of each of the multiple pressure equalization control valves is interconnected through pressure equalization pipelines. One end of each of the multiple product gas control valves is connected to the outlet of each of the multiple adsorption towers, and the other end of each of the multiple product gas control valves is interconnected through product gas connection pipelines. The product gas connection pipeline is connected to the inlet of the ethylene product gas buffer tank, and the outlet of the ethylene product gas buffer tank is used to output ethylene product gas.

[0007] Furthermore, the device also includes a product gas flow regulating valve, one end of which is connected to the outlet of the ethylene product gas buffer tank, and the other end of which is used to continuously and stably output ethylene product gas.

[0008] Furthermore, there are four adsorption towers, designated as the first, second, third, and fourth adsorption towers; four product gas control valves, designated as the first, second, third, and fourth product gas control valves; four pressure equalization control valves, designated as the first, second, third, and fourth pressure equalization control valves; four feed gas control valves, designated as the first, second, third, and fourth feed gas control valves; four ethane replacement control valves, designated as the first, second, third, and fourth ethane replacement control valves; and four vacuum control valves, designated as the first, second, third, and fourth vacuum control valves. The use of four adsorption towers facilitates continuous processing of the ethane-ethylene mixture while maintaining stable pressure, thereby improving the processing efficiency of the ethane-ethylene mixture.

[0009] Furthermore, the ethane-selective porous material used is Cu(Qc)2, which can be synthesized at room temperature, has low raw material cost, simple preparation process, is easy to scale up production, and has a significant adsorption effect on ethane.

[0010] The method for separating ethane and ethylene using the apparatus described above includes the following steps:

[0011] 1) First time period: Open the first raw material gas control valve and the first product gas control valve to execute the adsorption of the first adsorption tower. At the same time, close the fourth raw material gas control valve, the fourth product gas control valve, and the second vacuum control valve. Open the second equalization control valve and the fourth equalization control valve to connect the second adsorption tower and the fourth adsorption tower. Execute the equalization rise of the second adsorption tower and the equalization fall of the fourth adsorption tower (when the unit is first started, i.e., when the first time period is executed for the first time, because the second adsorption tower has not yet been evacuated and the fourth adsorption tower has not yet been adsorbed, when the equalization rise of the second adsorption tower and the equalization fall of the fourth adsorption tower are executed, only the corresponding valves are activated, and there is no actual equalization rise and fall effect). At the same time, open the third ethane replacement control valve and the third product gas control valve to execute the ethane replacement of the third adsorption tower. Before the ethane in the third adsorption tower penetrates, close the third ethane replacement control valve and the third product gas control valve.

[0012] 2) Second time period: Continue adsorption in the first adsorption tower. At the same time, close the second and fourth pressure equalization control valves, open the second product gas control valve, and pressurize the second adsorption tower. At the same time, open the third vacuum control valve and evacuate the third adsorption tower. At the same time, open the fourth ethane replacement control valve and the fourth product gas control valve and ethane replacement in the fourth adsorption tower.

[0013] 3) Third time period: Close the first raw material gas control valve and the first product gas control valve, open the first pressure equalization control valve and the third pressure equalization control valve, execute the pressure equalization of the first adsorption tower and the pressure equalization of the third adsorption tower, at the same time, open the second raw material gas control valve and the second product gas control valve, execute the adsorption of the second adsorption tower, and at the same time, continue to execute the ethane replacement of the fourth adsorption tower. Before the ethane in the fourth adsorption tower breaks through, close the fourth ethane replacement control valve and the fourth product gas control valve.

[0014] 4) Fourth time period: Close the first pressure equalization control valve, open the first ethane replacement control valve and the first product gas control valve to perform ethane replacement in the first adsorption tower. At the same time, continue adsorption in the second adsorption tower. Simultaneously, close the third pressure equalization control valve, open the third product gas control valve to perform pressure increase in the third adsorption tower, and open the fourth vacuum control valve to perform vacuuming in the fourth adsorption tower.

[0015] 5) Fifth time period: Continue to perform ethane replacement in the first adsorption tower. Before the ethane in the first adsorption tower breaks through, close the first ethane replacement control valve and the first product gas control valve. At the same time, close the second feed gas control valve, the second product gas control valve, and the fourth vacuum control valve. Open the second equalization control valve and the fourth equalization control valve to perform equalization and pressure reduction in the second adsorption tower and equalization and pressure increase in the fourth adsorption tower. At the same time, open the third feed gas control valve to perform adsorption in the third adsorption tower.

[0016] 6) Sixth time period: Open the first vacuum control valve to perform vacuuming of the first adsorption tower. At the same time, close the second pressure equalization control valve, open the second ethane replacement control valve and the second product gas control valve to perform ethane replacement of the second adsorption tower. At the same time, continue adsorption of the third adsorption tower. At the same time, close the fourth pressure equalization control valve, open the fourth product gas control valve, and perform pressurization of the fourth adsorption tower.

[0017] 7) Seventh time period: Close the first vacuum control valve, open the first pressure equalization control valve and the third pressure equalization control valve, execute the equalization of the first adsorption tower and the equalization of the third adsorption tower, and at the same time, continue to execute the ethane replacement of the second adsorption tower. Before the ethane in the second adsorption tower breaks through, close the second ethane replacement control valve and the second product gas control valve. At the same time, open the fourth raw material gas control valve and execute the adsorption of the fourth adsorption tower.

[0018] 8) Eighth time period: Close the first equalization control valve, open the first product gas control valve, and perform the pressurization of the first adsorption tower. At the same time, open the second vacuum control valve and perform the vacuuming of the second adsorption tower. Simultaneously, close the third equalization control valve, open the third ethane replacement control valve and the third product gas control valve, and perform ethane replacement of the third adsorption tower. At the same time, continue the adsorption of the fourth adsorption tower.

[0019] 9) Repeat steps 1) to 8).

[0020] The beneficial effects of this invention are as follows: The apparatus and method for separating ethane and ethylene described in this invention mainly employ adsorption + ethane replacement, which not only achieves efficient separation of ethane and ethylene, alleviating the pressure on ethylene resource demand, but also enables continuous treatment of ethane-ethylene mixed gas, thereby improving treatment efficiency. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the device described in this invention;

[0024] Figure 2 This is a schematic diagram of the adsorption curve of ethane-ethylene by Cu(Qc)2, an ethane-selective porous material, at 298 K.

[0025] Figure 3 This is a schematic diagram of the separation curve of Cu(Qc)2 on an ethane-ethylene mixture (volume fraction ratio of 1 / 1) at room temperature and atmospheric pressure (25℃, 1 bar).

[0026] Figure 4 This is a schematic diagram of the separation curves of ethane and ethylene when the ethane-ethylene mixture is treated using the method described in this invention at room temperature and atmospheric pressure (25°C, 1 bar).

[0027] In the diagram: 1-Compressor, 2-Inlet buffer tank, 3-Vacuum pump, 4-Ethane product gas buffer tank, 5-Ethylene product gas buffer tank, 6-Product gas flow regulating valve, 11-First vacuum control valve, 12-Second vacuum control valve, 13-Third vacuum control valve, 14-Fourth vacuum control valve, 21-First ethane replacement control valve, 22-Second ethane replacement control valve, 23-Third ethane replacement control valve, 24-Fourth ethane replacement control valve, 31-First feed gas control valve. 32-Second raw material gas control valve, 33-Third raw material gas control valve, 34-Fourth raw material gas control valve, 41-First adsorption tower, 42-Second adsorption tower, 43-Third adsorption tower, 44-Fourth adsorption tower, 51-First pressure equalization control valve, 52-Second pressure equalization control valve, 53-Third pressure equalization control valve, 54-Fourth pressure equalization control valve, 61-First product gas control valve, 62-Second product gas control valve, 63-Third product gas control valve, 64-Fourth product gas control valve. Detailed Implementation

[0028] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0030] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] like Figure 1 As shown, an apparatus for separating ethane and ethylene includes a compressor 1, an inlet buffer tank 2, an ethylene product flow control valve, an ethylene product gas buffer tank 5, an ethane product gas buffer tank 4, a vacuum pump 3, multiple adsorption towers, each filled with an ethane-selective porous material, multiple product gas control valves, multiple pressure equalization control valves, multiple feed gas control valves, multiple ethane displacement control valves, and multiple vacuum control valves. One end of the compressor 1 is used to introduce the ethane-ethylene mixture, and the other end of the compressor 1 is connected to one end of the inlet buffer tank 2. The other end of the inlet buffer tank 2 is connected to the inlet of the multiple adsorption towers through the multiple feed gas control valves. One end of each of the multiple vacuum control valves is connected to the inlet of the multiple adsorption towers, and the other end of each of the multiple vacuum control valves is connected to the inlet of the vacuum pump 3. The outlet of vacuum pump 3 is connected to the inlet of ethane product gas buffer tank 4. One end of multiple ethane replacement control valves is connected to the inlet of multiple adsorption towers, and the other end of multiple ethane replacement control valves is connected to the replacement end of ethane product gas buffer tank 4. The outlet of ethane product gas buffer tank 4 is used to output ethane product gas. One end of multiple pressure equalization control valves is connected to the outlet of multiple adsorption towers, and the other end of multiple pressure equalization control valves is connected to each other through pressure equalization pipelines. One end of multiple product gas control valves is connected to the outlet of multiple adsorption towers, and the other end of multiple product gas control valves is connected to each other through product gas connection pipelines. The product gas connection pipeline is connected to the inlet of ethylene product gas buffer tank 5, and the outlet of ethylene product gas buffer tank 5 is used to output ethylene product gas.

[0032] In specific implementation, the device also includes a product gas flow regulating valve 6. One end of the product gas flow regulating valve 6 is connected to the outlet end of the ethylene product gas buffer tank 5, and the other end of the product gas flow regulating valve 6 is used to continuously and stably output ethylene product gas.

[0033] In this specific embodiment, there are four adsorption towers, namely the first adsorption tower 41, the second adsorption tower 42, the third adsorption tower 43, and the fourth adsorption tower 44; four product gas control valves, namely the first product gas control valve 61, the second product gas control valve 62, the third product gas control valve 63, and the fourth product gas control valve 64; four pressure equalization control valves, namely the first pressure equalization control valve 51, the second pressure equalization control valve 52, the third pressure equalization control valve 53, and the fourth pressure equalization control valve 54; four raw material gas control valves, namely the first raw material gas control valve 31, the second raw material gas control valve 32, the third raw material gas control valve 33, and the fourth raw material gas control valve 34; four ethane replacement control valves, namely the first ethane replacement control valve 21, the second ethane replacement control valve 22, the third ethane replacement control valve 23, and the fourth ethane replacement control valve 24; and four vacuum control valves, namely the first vacuum control valve 11, the second vacuum control valve 12, the third vacuum control valve 13, and the fourth vacuum control valve 14. Four adsorption towers are installed to facilitate continuous treatment of the ethane-ethylene mixture while maintaining stable pressure, thereby improving the treatment efficiency of the ethane-ethylene mixture.

[0034] In this specific embodiment, the ethane-selective porous material used is Cu(Qc)2. This material can be synthesized at room temperature, has low raw material cost, a simple preparation process, and is easy to scale up. It exhibits significant adsorption of ethane. Specific performance details can be found in [link to specific embodiment]. Figure 2 , 3 As shown.

[0035] The method for separating ethane and ethylene using the apparatus described above includes the following steps:

[0036] 1) First Time Period: Open the first raw material gas control valve 31 and the first product gas control valve 61 to execute the adsorption of the first adsorption tower 41. That is, the ethane-ethylene mixture enters the first adsorption tower 41 from the first raw material gas control valve 31. Most of the weakly adsorbed component, ethylene, passes through the first product gas control valve 61, the ethylene product gas buffer tank 5, and the product gas flow regulating valve 6 before being output as ethylene product gas. At the same time, close the fourth raw material gas control valve 34, the fourth product gas control valve 64, and the second vacuum control valve 12. Open the second equalization control valve 52 and the fourth equalization control valve 54 to connect the second adsorption tower 42 and the fourth adsorption tower 44, and execute the equalization of the rise in the second adsorption tower 42 and the equalization of the fall in the fourth adsorption tower 44 (when the unit is just started up, i.e., the first execution of the first time). During the interval, since the second adsorption tower 42 has not yet been evacuated and the fourth adsorption tower 44 has not yet been adsorbed, when the equalization of the second adsorption tower 42 and the equalization of the fourth adsorption tower 44 are performed, only the corresponding valves are activated, without any actual equalization of the rise and fall. At the same time, the third ethane replacement control valve 23 and the third product gas control valve 63 are opened. Ethane flows into the third adsorption tower 43 through the ethane product gas buffer tank 4 and the third ethane replacement control valve 23 to perform ethane replacement in the third adsorption tower 43. The ethylene replaced passes through the third product gas control valve 63 and the ethylene product gas buffer tank 5 and is output as ethylene product gas. Before the ethane in the third adsorption tower 43 penetrates, the third ethane replacement control valve 23 and the third product gas control valve 63 are closed.

[0037] 2) Second time period: Adsorption in the first adsorption tower 41 continues. Simultaneously, the second pressure equalization control valve 52 and the fourth pressure equalization control valve 54 are closed, and the second product gas control valve 62 is opened. This allows some ethylene product gas from the first adsorption tower 41 to flow back to the first adsorption tower 41 via the first product gas control valve 61 and the second product gas control valve 62, thus pressurizing the second adsorption tower 42. Simultaneously, the third vacuum control valve 13 is opened, and the vacuum pump 3 performs vacuuming of the third adsorption tower 43. The extracted gas passes through the vacuum pump 3 and the ethane product gas buffer tank 4 before being output as ethane product gas. Simultaneously, the fourth ethane replacement control valve 24 and the fourth product gas control valve 64 are opened to perform ethane replacement in the fourth adsorption tower 44.

[0038] 3) Third time period: Close the first raw material gas control valve 31 and the first product gas control valve 61, open the first equalization control valve 51 and the third equalization control valve 53, connect the first adsorption tower 41 and the third adsorption tower 43, and perform equalization of pressure drop in the first adsorption tower 41 and equalization of pressure rise in the third adsorption tower 43. At the same time, open the second raw material gas control valve 32 and the second product gas control valve 62 to perform adsorption in the second adsorption tower 42. At the same time, continue to perform ethane replacement in the fourth adsorption tower 44. Before the ethane in the fourth adsorption tower 44 breaks through, close the fourth ethane replacement control valve 24 and the fourth product gas control valve 64.

[0039] 4) Fourth time period: Close the first equalization control valve 51, open the first ethane replacement control valve 21 and the first product gas control valve 61 to perform ethane replacement in the first adsorption tower 41. At the same time, continue adsorption in the second adsorption tower 42. Simultaneously, close the third equalization control valve 53, open the third product gas control valve 63 to perform pressure increase in the third adsorption tower 43, and open the fourth vacuum control valve 14 to perform vacuuming in the fourth adsorption tower 44.

[0040] 5) Fifth time period: Continue to perform ethane replacement in the first adsorption tower 41. Before the ethane in the first adsorption tower 41 breaks through, close the first ethane replacement control valve 21 and the first product gas control valve 61. At the same time, close the second raw material gas control valve 32, the second product gas control valve 62 and the fourth vacuum control valve 14. Open the second equalization control valve 52 and the fourth equalization control valve 54 to perform equalization of pressure drop in the second adsorption tower 42 and equalization of pressure rise in the fourth adsorption tower 44. At the same time, open the third raw material gas control valve 33 to perform adsorption in the third adsorption tower 43.

[0041] 6) Sixth time period: Open the first vacuum control valve 11 to perform vacuuming of the first adsorption tower 41. At the same time, close the second pressure equalization control valve 52, open the second ethane replacement control valve 22 and the second product gas control valve 62 to perform ethane replacement of the second adsorption tower 42. At the same time, continue adsorption of the third adsorption tower 43. At the same time, close the fourth pressure equalization control valve 54, open the fourth product gas control valve 64 to perform pressurization of the fourth adsorption tower 44.

[0042] 7) Seventh time period: Close the first vacuum control valve 11, open the first pressure equalization control valve 51 and the third pressure equalization control valve 53, and perform the equalization of pressure increase in the first adsorption tower 41 and the equalization of pressure decrease in the third adsorption tower 43. At the same time, continue to perform ethane replacement in the second adsorption tower 42. Before the ethane in the second adsorption tower 42 breaks through, close the second ethane replacement control valve 22 and the second product gas control valve 62. At the same time, open the fourth raw material gas control valve 34 and perform adsorption in the fourth adsorption tower 44.

[0043] 8) Eighth time period: Close the first equalization control valve 51, open the first product gas control valve 61, and perform pressure increase of the first adsorption tower 41. At the same time, open the second vacuum control valve 12 and perform vacuuming of the second adsorption tower 42. Simultaneously, close the third equalization control valve 53, open the third ethane replacement control valve 23 and the third product gas control valve 63, and perform ethane replacement of the third adsorption tower 43. At the same time, continue adsorption of the fourth adsorption tower 44.

[0044] 9) Repeat steps 1) to 8) as shown in Table 1 below.

[0045]

[0046] It should be noted that the specific time of each time period is related to the flow rate of the ethane-ethylene mixture and the specifications of the adsorption tower. Those skilled in the art can obtain the optimal results for the specific time of each time period through experiments when conducting actual operations.

[0047] In practice, the adsorption pressure of each adsorption tower during adsorption is 0.2 MPa to 0.5 MPa, the pressure of each adsorption tower during ethane replacement is 0.1 MPa, and the pressure of each adsorption tower during vacuuming is 0.01 MPa.

[0048] Experiments have verified that the apparatus and method described in this invention achieve the separation of ethane and ethylene, with a recovered ethylene concentration ≥99.95%, an ethane concentration ≥99%, and a combined yield of ethane and ethylene ≥95%. Figure 4 As shown.

[0049] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A method for separating ethane and ethylene, characterized in that, The method is implemented using the following separation device, which includes a compressor (1), an inlet buffer tank (2), an ethylene product gas buffer tank (5), an ethane product gas buffer tank (4), a vacuum pump (3), four adsorption towers, each filled with Cu(Qc)2, four product gas control valves, four pressure equalization control valves, four raw material gas control valves, four ethane replacement control valves, and four vacuum control valves. The four adsorption towers are the first adsorption tower (41), the second adsorption tower (42), the third adsorption tower (43), and the fourth adsorption tower (44), respectively. The four product gas control valves are the first product gas control valve (61), the second product gas control valve (62), the third product gas control valve (63), and the fourth product gas control valve (64), respectively. The four equalizing control valves are the first equalizing control valve (51), the second equalizing control valve (52), the third equalizing control valve (53), and the fourth equalizing control valve (54). The four raw material gas control valves are the first raw material gas control valve (31), the second raw material gas control valve (32), the third raw material gas control valve (33), and the fourth raw material gas control valve (34). The four ethane replacement control valves are the first ethane replacement control valve (21), the second ethane replacement control valve (22), the third ethane replacement control valve (23), and the fourth ethane replacement control valve (24). The four vacuum control valves are the first vacuum control valve (11), the second vacuum control valve (12), the third vacuum control valve (13), and the fourth vacuum control valve (14). One end of the compressor (1) is used to introduce ethane-ethylene mixture gas, and the other end of the compressor (1) is connected to one end of the inlet buffer tank (2). The other end of the inlet buffer tank (2) is connected to the inlet of the four adsorption towers through four raw material gas control valves respectively. One end of the first vacuum control valve (11) and one end of the first ethane replacement control valve (21) are both connected to the inlet of the first adsorption tower (41). One end of the second vacuum control valve (12) and one end of the second ethane replacement control valve (22) are both connected to the inlet of the second adsorption tower (42). One end of the third vacuum control valve (13) and one end of the third ethane replacement control valve (23) are both connected to the inlet of the third adsorption tower (43). One end of the fourth vacuum control valve (14) is connected to the inlet of the third adsorption tower (43). One end of the first ethane displacement control valve (24) is connected to the inlet of the fourth adsorption tower (44), and the other end of the four vacuum control valves is connected to the inlet of the vacuum pump (3). The outlet of the vacuum pump (3) is connected to the inlet of the ethane product gas buffer tank (4), and the other end of the four ethane displacement control valves is connected to the displacement end of the ethane product gas buffer tank (4). The outlet of the ethane product gas buffer tank (4) is used to output ethane product gas. One end of the first equalizing control valve (51) and one end of the first product gas control valve (61) are connected to the outlet of the first adsorption tower (41), and one end of the second equalizing control valve (52) and one end of the second product gas control valve (62) are connected to the outlet of the second adsorption tower (42).One end of the third equalizing control valve (53) and one end of the third product gas control valve (63) are both connected to the outlet of the third adsorption tower (43). One end of the fourth equalizing control valve (54) and one end of the fourth product gas control valve (64) are both connected to the outlet of the fourth adsorption tower (44). The other ends of the four equalizing control valves are interconnected through equalizing pipes. The other ends of the four product gas control valves are interconnected through product gas connecting pipes. The product gas connecting pipes are connected to the inlet of the ethylene product gas buffer tank (5). The outlet of the ethylene product gas buffer tank (5) is used to output ethylene product gas. The method of separation using the above separation device includes the following steps: 1) First time period: Open the first raw material gas control valve (31) and the first product gas control valve (61) to perform adsorption in the first adsorption tower (41). At the same time, close the fourth raw material gas control valve (34), the fourth product gas control valve (64) and the second vacuum control valve (12). Open the second equalization control valve (52) and the fourth equalization control valve (54) to connect the second adsorption tower (42) and the fourth adsorption tower (44) to perform equalization of the second adsorption tower (42) and equalization of the fourth adsorption tower (44). At the same time, open the third ethane replacement control valve (23) and the third product gas control valve (63) to perform ethane replacement in the third adsorption tower (43). Before the ethane in the third adsorption tower (43) penetrates, close the third ethane replacement control valve (23) and the third product gas control valve (63). 2) Second time period: Continue adsorption in the first adsorption tower (41), while closing the second equalization control valve (52) and the fourth equalization control valve (54), opening the second product gas control valve (62), and pressurizing the second adsorption tower (42); at the same time, open the third vacuum control valve (13) and evacuate the third adsorption tower (43); at the same time, open the fourth ethane replacement control valve (24) and the fourth product gas control valve (64) and perform ethane replacement in the fourth adsorption tower (44); 3) Third time period: Close the first raw material gas control valve (31) and the first product gas control valve (61), open the first equalization control valve (51) and the third equalization control valve (53), perform equalization of the first adsorption tower (41) and equalization of the third adsorption tower (43), at the same time, open the second raw material gas control valve (32) and the second product gas control valve (62), perform adsorption in the second adsorption tower (42), at the same time, continue to perform ethane replacement in the fourth adsorption tower (44), and close the fourth ethane replacement control valve (24) and the fourth product gas control valve (64) before the ethane in the fourth adsorption tower (44) breaks through. 4) Fourth time period: Close the first equalization control valve (51), open the first ethane replacement control valve (21) and the first product gas control valve (61) to perform ethane replacement in the first adsorption tower (41), while continuing adsorption in the second adsorption tower (42), while closing the third equalization control valve (53), opening the third product gas control valve (63) to perform pressurization in the third adsorption tower (43), and opening the fourth vacuum control valve (14) to perform vacuuming in the fourth adsorption tower (44); 5) Fifth time period: Continue to perform ethane replacement in the first adsorption tower (41). Before the ethane in the first adsorption tower (41) penetrates, close the first ethane replacement control valve (21) and the first product gas control valve (61). At the same time, close the second raw material gas control valve (32), the second product gas control valve (62) and the fourth vacuum control valve (14). Open the second equalization control valve (52) and the fourth equalization control valve (54) to perform equalization of pressure drop in the second adsorption tower (42) and equalization of pressure rise in the fourth adsorption tower (44). At the same time, open the third raw material gas control valve (33) to perform adsorption in the third adsorption tower (43). 6) Sixth time period: Open the first vacuum control valve (11) to perform vacuuming of the first adsorption tower (41), and at the same time, close the second equalization control valve (52), open the second ethane replacement control valve (22) and the second product gas control valve (62) to perform ethane replacement of the second adsorption tower (42), and at the same time, continue to perform adsorption of the third adsorption tower (43), and at the same time, close the fourth equalization control valve (54), open the fourth product gas control valve (64) to perform pressurization of the fourth adsorption tower (44); 7) Seventh time period: Close the first vacuum control valve (11), open the first equalization control valve (51) and the third equalization control valve (53), perform equalization of the first adsorption tower (41) and equalization of the third adsorption tower (43), and at the same time, continue to perform ethane replacement in the second adsorption tower (42). Before the ethane in the second adsorption tower (42) penetrates, close the second ethane replacement control valve (22) and the second product gas control valve (62), and at the same time, open the fourth raw material gas control valve (34) to perform adsorption in the fourth adsorption tower (44); 8) Eighth time period: Close the first equalization control valve (51), open the first product gas control valve (61), and perform the pressurization of the first adsorption tower (41). At the same time, open the second vacuum control valve (12) and perform the vacuuming of the second adsorption tower (42). At the same time, close the third equalization control valve (53), open the third ethane replacement control valve (23) and the third product gas control valve (63), and perform the ethane replacement of the third adsorption tower (43). At the same time, continue the adsorption of the fourth adsorption tower (44). 9) Repeat steps 1) to 8).

2. The method for separating ethane and ethylene according to claim 1, characterized in that, The device also includes a product gas flow regulating valve (6), one end of which is connected to the outlet of the ethylene product gas buffer tank (5), and the other end of which is used to continuously and stably output ethylene product gas.

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