CN221107659U - Rectifying column tail gas treatment system - Google Patents

Abstract

The utility model relates to a rectifying tower tail gas treatment system, which comprises a gas-liquid mixer, a gas-liquid mixing and conveying pump, a flash tank and a buffer tank, wherein a pipeline for conveying the tail gas of a triethylene glycol rectifying tower is communicated with one inlet of the gas-liquid mixer, an outlet of the gas-liquid mixer is communicated with the gas-liquid mixing and conveying pump, the gas-liquid mixing and conveying pump is communicated with the flash tank, the bottom of the flash tank is communicated with the other inlet of the gas-liquid mixer through a pipeline, the flash tank is communicated with the buffer tank through a pipeline, the buffer tank is provided with an output pipeline for outputting gas, the output pipeline is used for conveying the gas to a reboiler, the buffer tank is also provided with an input pipeline for conveying combustion gas, and the input pipeline is used for inputting the combustion gas into the buffer tank; the system can fully utilize tail gas exhausted by the TEG rectifying tower, can avoid the loss of natural gas, is beneficial to saving energy and reducing cost, can ensure that the gas quantity input into a reboiler of the rectifying tower is relatively stable, and does not have the condition of great fluctuation.

Description

Rectifying column tail gas treatment system

Technical Field

The utility model relates to the technical field of pollution gas monitoring, in particular to a rectifying tower tail gas treatment system.

Background

Dehydration of natural gas is a very important process flow for pretreatment of natural gas. Untreated natural gas produced from a formation may contain saturated water, free water, and liquid heavy hydrocarbons (wet natural gas), and thus may require dehydration of the wet natural gas during production and transportation. The process treatment method for dehydration of natural gas can be classified into a low-temperature separation process, a solvent absorption process, a solid adsorption process, a membrane separation process, and the like according to the principle. The solvent absorption process also comprises solvent absorption processes such as Ethylene Glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG) and the like. In the production and treatment operation of many gas fields, the triethylene glycol (TEG) dehydration process has a series of advantages of easy regeneration, good thermal stability and the like, and is widely applied to the gas field dehydration process.

The existing natural gas dehydration process system comprises a plurality of rectifying towers (or called rectifying columns), wherein the tail gas discharged from the TEG rectifying towers is usually directly sent to a burning tower for combustion treatment, and the tail gas discharged from the low-pressure rectifying towers is usually sent to a natural gas original high-pressure natural gas pipe network through multistage compression of compressors. The problems with this process are: firstly, the tail gas of the rectifying tower contains a large amount of natural gas, the heat value is high, the combustion tail gas also needs to be externally added with natural gas for combustion supporting combustion, and more natural gas is additionally consumed; secondly, the compressor is adopted for compression, the compression ratio is large, 5-level compression is needed, the power consumption is high, the equipment investment is expensive, and the operation is unstable. In order to solve the technical problem, a tail gas recovery system is designed, the system is provided with a cooler, a gas-liquid separator, a gas-liquid mixer, a gas-liquid mixing pump, a flash tank and a buffer tank, tail gas from a TEG rectifying tower can sequentially pass through the cooler and the gas-liquid separator, then is mixed with triethylene glycol (TEG) in the gas-liquid mixer, is compressed by the gas-liquid mixing pump and then is input into the flash tank for flash evaporation, and the gas after flash evaporation is sent into the buffer tank and finally is sent to a rectifying tower reboiler in a natural gas station through the buffer tank to be used as combustion gas. After the tail gas recovery system is configured in the natural gas station, natural gas contained in the tail gas of the TEG rectifying tower can be fully utilized, so that the loss of the natural gas can be avoided, the consumption of the natural gas can be effectively reduced, a compressor is not required to be configured for compression, and the energy consumption and the cost are saved. But in actual operation it is found that: because tail gas and triethylene glycol (TEG) flash evaporation are carried out in the flash tank, the flash evaporation amount is difficult to accurately control, when the flash evaporation amount is large, a large amount of gas is separated and is output to the rectifying tower reboiler at the rear end through the buffer tank, when the flash evaporation amount is small, little or even no gas is separated from the separated gas, so that the buffer tank does not have gas output, and therefore the fluctuation of the gas output from the buffer tank is large and unstable, and the stable heat is not generated by the rectifying tower reboiler at the rear end, so that the problem is to be solved.

Disclosure of Invention

An object of the first aspect of the present utility model is to solve the above-mentioned technical problems, and provide a tail gas recovery system, which can fully utilize the tail gas discharged from a TEG rectifying tower and ensure that the amount of gas input into a reboiler of the rectifying tower is relatively stable, and has the main concept that:

The rectifying tower tail gas treatment system comprises a gas-liquid mixer, a gas-liquid mixing pump, a flash tank and a buffer tank, wherein a pipeline for conveying the tail gas of the triethylene glycol rectifying tower is communicated with one inlet of the gas-liquid mixer, an outlet of the gas-liquid mixer is communicated with the gas-liquid mixing pump, the gas-liquid mixing pump is communicated with the flash tank, the bottom of the flash tank is communicated with the other inlet of the gas-liquid mixer through the pipeline,

The flash tank is communicated with the buffer tank through a pipeline, the buffer tank is provided with an output pipeline for outputting gas and is used for conveying the gas to the reboiler, and the buffer tank is also provided with an input pipeline for inputting combustion gas and is used for inputting the combustion gas into the buffer tank. In the scheme, the gas-liquid mixer, the gas-liquid mixing pump and the flash tank are configured, so that the gas-liquid mixer, the gas-liquid mixing pump and the flash tank can form a circulating path for circulating the triethylene glycol solution, the triethylene glycol solution can circulate in the system, the circulating path is simpler, and the cost is reduced; at gas-liquid mixer department, triethylene glycol and tail gas intensive mixing to effective pressure boost in gas-liquid mixing delivery pump department realizes the pressure boost and carries, need not to dispose the compressor and compresses, more practice thrift energy consumption and cost, get into in the gas-liquid mixer at last and carry out the flash distillation and realize gas-liquid separation, the gas after the flash distillation is input in the buffer tank, and the output pipeline through the buffer tank is to reboiler, so that the rectifying column reboiler in the natural gas station is utilized as the combustion gas, both can avoid the waste and the loss of natural gas, can effectively reduce the consumption of natural gas again. In this scheme, through the input pipeline that is used for the input combustion gas for the buffer tank configuration to through the input a certain amount of combustion gas in to the buffer tank in actual operation in-process, the combustion gas of input buffer tank is together with the gas in the buffer tank via output pipeline transmission to the reboiler, can make the gas quantity that is transmitted to the reboiler stable relatively through the input of control combustion gas, ensure can not appear undulant by a wide margin for the heat generation volume of rear end rectifying column reboiler is stable, thereby can effectively solve the influence that flash distillation volume undulant brought.

In order to further save the combustion gas, the flash tank and/or the buffer tank are/is provided with a pressure sensor, the input pipeline is provided with a control valve, the pressure sensor and the control valve are respectively and electrically connected with the controller, and the controller is used for controlling the control valve. In this scheme, through configuration pressure sensor in the flash tank to utilize pressure sensor to detect the gaseous phase pressure in the flash tank, so that judge the volume of gas in the flash tank, through setting up the control valve at the input pipeline, and make the control valve be connected with the controller electricity, make the aperture of control valve can be controlled according to the gaseous phase pressure in the flash tank to the controller, not only can effectively solve the influence that the fluctuation of flash quantity brought, make the gaseous volume of this system output stable, can effectively reduce the input of combustion gas moreover, be favorable to energy-conservation and reduce cost.

Preferably, the controller adopts a PLC, and/or the control valve adopts a solenoid valve.

To solve the problem of convenient replenishment of triethylene glycol, further, a triethylene glycol input pipeline is also included, and the triethylene glycol input pipeline is communicated with the flash tank. When fresh triethylene glycol is needed to be replenished, the triethylene glycol can be directly replenished into the flash tank through the triethylene glycol input pipeline, so that the system is very convenient.

Further, the triethylene glycol input pipeline is also provided with a valve. So as to control whether the triethylene glycol is replenished into the flash tank.

In order to simplify the structure, further, the gas-liquid mixing pump is communicated with the flash tank through a pipeline, and the pipeline is not provided with a cooler. The temperature is increased in the process of pressurizing the gas-liquid mixture by utilizing the gas-liquid mixing pump, but the temperature change range is found to be in an acceptable range in the actual operation process, and the subsequent flash evaporation process is not influenced, so that a cooler is not required to be arranged between the gas-liquid mixing pump and the flash evaporation tank for simplifying the structure and reducing the cost, and the gas-liquid mixing pump and the flash evaporation tank are only communicated through a pipeline.

In order to solve the problem of discharging triethylene glycol circulating liquid, the circulating liquid purifying device further comprises a circulating liquid output pipeline, one end of the circulating liquid output pipeline is connected with the pipeline through a pipe, the other end of the circulating liquid output pipeline is used for being communicated with a triethylene glycol rectifying tower, the pipeline is arranged on a valve, and the circulating liquid output pipeline is also provided with the valve. In the actual operation process, the flow direction of the triethylene glycol circulating liquid can be controlled through the cooperation of the two valves, so that the circulating flow of the triethylene glycol circulating liquid can be realized, and the triethylene glycol circulating liquid can be conveniently discharged.

Preferably, the top of the flash tank is in communication with the top of the buffer tank via a conduit. Is more beneficial to the transportation of gas.

Preferably, the output conduit communicates with the top of the buffer vessel and/or the input conduit communicates with the top of the buffer vessel.

Preferably, the buffer tank has a volume less than the volume of the flash tank. That is, in the scheme, a small buffer tank is configured to achieve the required effect, thereby being beneficial to reducing the cost.

The second aspect of the present utility model is to solve the problem of reducing the water content in the tail gas, and further comprises a gas-liquid separator for performing gas-liquid separation, wherein an inlet of the gas-liquid separator is used for inputting the tail gas, a gas phase outlet of the gas-liquid separator is communicated with the gas-liquid mixer through a pipeline, a liquid phase outlet of the gas-liquid separator is provided with a waste water pipeline, and the waste water pipeline is provided with a drainage pump. In the scheme, the gas-liquid separator is arranged at the upstream of the gas-liquid mixer so as to remove water in the tail gas as much as possible, so that the tail gas is as dry as possible, and the tail gas after the subsequent utilization treatment is more favorable.

Further, the device also comprises a cooler, one port of the cooler is used for inputting tail gas, the other port communicated with the cooler is communicated with the gas-liquid separator, and the cooler is used for condensing the tail gas. The method is more favorable for realizing better gas-liquid separation effect in the gas-liquid separator so as to remove the moisture in the tail gas as much as possible.

Further, a foam remover is arranged at the gas phase outlet of the gas-liquid separator. Is used for removing entrained condensate and effectively reducing the water content of gas.

Compared with the prior art, the tail gas treatment system of the rectifying tower provided by the utility model can fully utilize the tail gas discharged by the TEG rectifying tower, avoid the loss of natural gas, is beneficial to energy conservation and cost reduction, and can ensure that the gas quantity input into a reboiler of the rectifying tower is relatively stable and does not have the condition of large fluctuation.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a rectifying tower tail gas treatment system according to embodiment 1 of the present utility model.

Fig. 2 is a schematic structural diagram of a rectifying tower tail gas treatment system according to embodiment 2 of the present utility model.

Fig. 3 is a schematic structural diagram of a rectifying tower tail gas treatment system according to embodiment 3 of the present utility model.

Description of the drawings

Cooler 1 and refrigerating unit 11

Gas-liquid separator 2, demister 21, drain pump 22

Gas-liquid mixer 3

Gas-liquid mixing pump 4 and circulating liquid output pipeline 41

Flash tank 5, triethylene glycol input line 51

Buffer tank 6, input pipe 61, control valve 62, output pipe 63, pressure sensor 64

And a valve 7.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model.

Example 1

Referring to fig. 1, in this embodiment, a rectifying tower tail gas treatment system is provided, which includes a gas-liquid mixer 3, a gas-liquid mixing pump 4, a flash tank 5 and a buffer tank 6, wherein,

As shown in fig. 1, the gas-liquid mixer 3 may be a conventional gas-liquid mixer 3, where the gas-liquid mixer 3 is provided with two inlets and two outlets, and the outlets are connected to the two inlets, and in operation, a pipeline for conveying tail gas of the triethylene glycol rectifying tower is connected to one of the inlets of the gas-liquid mixer 3, as shown in fig. 1. At the same time, the bottom of the flash tank 5 is in communication with another inlet of the gas-liquid mixer 3 through another pipe, as shown, so that the tail gas and triethylene glycol (or referred to as triethylene glycol solution) can be thoroughly mixed in the gas-liquid mixer 3. In the course of the implementation thereof,

As shown in fig. 1, the outlet of the gas-liquid mixer 3 is communicated with the gas-liquid mixing pump 4, and in practice, the gas-liquid mixing pump 4 can be preferably an existing gas-liquid mixing pump 4 so as to effectively increase the pressure of the gas-liquid mixture.

As shown in fig. 1, the gas-liquid mixing pump 4 is in communication with the flash tank 5, and in operation, the gas-liquid mixing pump 4 may be in communication with the flash tank 5 via a pipe for assembly. The flash tank 5 may be in communication with the buffer tank 6 via a conduit, for example, as shown in fig. 1, and in practice, the top of the flash tank 5 may be in communication with the top of the buffer tank 6 via a conduit, which may further facilitate gas delivery.

As shown in fig. 1, the buffer tank 6 is provided with an output pipe 63 for outputting gas so that the gas is sent to the reboiler by the output pipe 63. In the present embodiment, the surge tank 6 is further provided with an input pipe 61 for inputting combustion gas so that the combustion gas is input into the surge tank 6 through the input pipe 61, as shown in fig. 1. In practice, the output conduit 63 may be in communication with the top of the buffer vessel 6, and correspondingly, the input conduit 61 may be in communication with the top of the buffer vessel 6, as shown in FIG. 1, to facilitate the output of gas.

In practice, the flash tank 5 and the buffer tank 6 may be existing tanks, but in practice, the volume of the buffer tank 6 may be smaller than that of the flash tank 5, i.e. in this embodiment, the required effect can be achieved by configuring a smaller buffer tank 6, which is beneficial to reducing the cost.

In this embodiment, the gas-liquid mixer 3, the gas-liquid mixing pump 4 and the flash tank 5 may form a circulation path for circulating the triethylene glycol solution, so that the triethylene glycol solution may circulate in the system, and the circulation path is simpler, which is beneficial to reducing the cost. At the gas-liquid mixer 3, triethylene glycol and tail gas are fully mixed, and are effectively pressurized at the gas-liquid mixing and conveying pump 4, so that pressurizing conveying is realized, a compressor is not required to be configured for compression, energy consumption and cost are saved, finally, gas and liquid completely enter the gas-liquid mixer 3 for flash evaporation to realize gas-liquid separation, the flashed gas is input into the buffer tank 6 and is conveyed to the reboiler through the output pipeline 63 of the buffer tank 6, and the rectifying tower reboiler in a natural gas station is used as combustion gas, so that the waste and loss of natural gas can be avoided, and the consumption of the natural gas can be effectively reduced.

The temperature is raised in the process of pressurizing the gas-liquid mixture by using the gas-liquid mixing pump 4, but the change range of the temperature is found to be in an acceptable range in the actual operation process, and the subsequent flash evaporation process and the flash evaporation effect are not affected, so that the cooler 1 is not required to be arranged on a pipeline communicated with the gas-liquid mixing pump 4 and the flash evaporation tank 5 in the implementation process, the structure can be further simplified, the cost can be reduced, and the cooler 1 can be arranged between the gas-liquid mixing pump 4 and the flash evaporation tank 5 in the implementation process.

In one mode of operation of the present system, the amount of combustion gas fed into the buffer tank 6 through the input pipe 61 may be greater than or much greater than the maximum amount of gas produced by the flash process, so that even if there is a large fluctuation in the amount of gas produced by the flash process, the influence on the amount of gas output from the output pipe 63 is small, so that the amount of gas output from the output pipe 63 may be kept stable, for example, when the maximum amount of gas produced by the flash process is 5Nm ³/d, the amount of combustion gas fed into the buffer tank 6 through the input pipe 61 may be 100Nm ³/d, and therefore, even if there is fluctuation in the amount of gas produced by the flash process, the amount of gas fed from the buffer tank 6 to the reboiler is kept substantially unchanged, so that the stability of gas can be effectively ensured.

Example 2

In order to save the amount of the combustion gas to be fed in and improve the versatility, the main difference between the present embodiment 2 and the above embodiment 1 is that the rectifying tower tail gas treatment system provided in this embodiment further includes a controller, the flash tank 5 and/or the buffer tank 6 is provided with a pressure sensor 64, the input pipe 61 is provided with a control valve 62, as shown in fig. 2, the pressure sensor 64 and the control valve 62 are electrically connected to the controller, respectively, the pressure sensor 64 is used for detecting the gas phase pressure in the flash tank 5 and/or the buffer tank 6, and feeding back to the controller, so that the controller is used for judging the amount of the gas in the flash tank 5, and at the same time, the controller can control the opening of the control valve 62 according to the gas phase pressure in the flash tank 5, so as to control the amount of the combustion gas fed in the flash tank 5 according to the gas amount in the flash tank 5. Therefore, the influence caused by fluctuation of the flash evaporation quantity can be effectively solved, the gas quantity output by the system is stable, more combustion gas is not required to be fed in to balance the fluctuation of the gas quantity in the flash evaporation tank 5, the feeding quantity of the combustion gas can be effectively reduced, and the energy conservation and the cost reduction are facilitated.

In implementation, the controller may preferably adopt a PLC, and of course, the controller may also adopt a common controller such as a PC, a single-chip microcomputer, an embedded chip, and the like. In practice, the control valve 62 may preferably be a solenoid valve. Of course, the control valve 62 may be an electrically operated valve, etc., and will not be illustrated here.

Since the triethylene glycol solution circulates among the gas-liquid mixer 3, the gas-liquid mixing pump 4 and the flash tank 5, after the triethylene glycol is recycled for a period of time, whether the triethylene glycol is required to be discharged to the triethylene glycol rectifying tower for treatment or not can be determined by manually analyzing the composition of the triethylene glycol. Thus, in a more sophisticated version, the system further comprises a circulating liquid output pipe 6341, one end of the circulating liquid output pipe 6341 being in communication with a pipe between the gas-liquid mixing pump 4 and the flash tank 5, and the other end of the circulating liquid output pipe 6341 being for communication with the triethylene glycol rectifying column, as shown in fig. 2, so that the circulating flowing triethylene glycol is fed into the triethylene glycol rectifying column through the circulating liquid output pipe 6341. In the implementation, the valve 7 is arranged in the pipeline between the gas-liquid mixing pump 4 and the flash tank 5, as shown in fig. 2, and meanwhile, the valve 7 is also arranged in the circulating liquid output pipeline 6341, so that in the actual operation process, the flow direction of the triethylene glycol circulating liquid can be controlled through the cooperation of the two valves 7, the circulating flow of the triethylene glycol circulating liquid can be realized, and the triethylene glycol circulating liquid can be conveniently discharged. In practice, the valve 7 may be a manual valve 7, requiring manual opening and closing. In practice, the valve 7 may be a control valve 62 such as a solenoid valve, and the control valve 62 is electrically connected to a controller, so that the controller can be used to control whether or not to output the triethylene glycol circulating liquid.

To facilitate the replenishment of triethylene glycol into the present system, in a further embodiment, the present system further comprises a triethylene glycol input pipe 6151, wherein the triethylene glycol input pipe 6151 is communicated with the flash tank 5, and when fresh triethylene glycol is required to be replenished, the triethylene glycol can be directly replenished into the flash tank 5 through the triethylene glycol input pipe 6151, which is very convenient. In practice, the triethylene glycol input line 6151 is also provided with a valve 7, as shown in fig. 2, to control whether the flash tank 5 is replenished with triethylene glycol via the valve 7. In practice, the valve 7 may be a manual valve 7 or a control valve 62 such as a solenoid valve, and the control valve 62 is electrically connected to a controller to control whether or not the triethylene glycol is replenished into the flash tank 5.

Example 3

For better recovery and utilization of the tail gas, the main difference between the embodiment 3 and the embodiment 1 or 2 is that the rectifying tower tail gas treatment system provided in this embodiment further includes a gas-liquid separator 2 for performing gas-liquid separation, and in implementation, the gas-liquid separator 2 may be an existing gas-liquid separator 2, the gas-liquid separator 2 is configured with an inlet, a gas phase outlet and a liquid phase outlet, as shown in fig. 3, the tail gas may be input into the gas-liquid separator 2 through the inlet of the gas-liquid separator 2, the gas phase outlet of the gas-liquid separator 2 may be communicated with the gas-liquid mixer 3 through a pipeline, and the liquid phase outlet of the gas-liquid separator 2 is configured with a waste water pipeline, as shown in fig. 3, and the waste water pipeline is configured with a drainage pump 22. In the actual operation process, the tail gas input into the gas-liquid separator 2 can be subjected to gas-liquid separation in the gas-liquid separator 2, the separated gas is discharged through a gas phase outlet, and the separated liquid is discharged through a liquid phase outlet and can be input into a sewage treatment facility of a natural gas station under the driving of the drainage pump 22. By arranging the gas-liquid separator 2 at the upstream of the gas-liquid mixer 3, water in the tail gas can be removed as much as possible, so that the tail gas is dried as much as possible, and the tail gas after the subsequent treatment can be utilized more favorably.

In a more perfect solution, a demister 21 is further disposed at the gas phase outlet of the gas-liquid separator 2, as shown in fig. 3, so that the demister 21 is used to remove the condensate entrained by the gas, so as to effectively reduce the water content of the gas.

In a more perfect scheme, the system further comprises a cooler 1, when the system is implemented, the cooler 1 can adopt the existing cooler 1, the cooler 1 is generally configured with two pipelines, one pipeline is used for connecting cooling water, the port of the other pipeline is used for inputting tail gas, the other port communicated with the other pipeline is communicated with the gas-liquid separator 2, in the actual operation process, the tail gas is conveyed along one pipeline of the cooler 1, the cooling water is conveyed along the other pipeline of the cooler 1 so as to exchange heat in the conveying process, the temperature of the tail gas is effectively reduced, the effect of condensing the tail gas is achieved, and the condensed tail gas is more beneficial to achieving a better gas-liquid separation effect in the gas-liquid separator 2 so as to remove water in the tail gas as much as possible. Of course, in a more sophisticated version, a refrigerating unit 11 is also included, as shown in fig. 3, the refrigerating unit 11 being in communication with one of the pipes of the cooler 1 through a cooling water pipe, so as to supply the cooler 1 with cooling water.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present utility model.

Claims (10)

1. A rectifying tower tail gas treatment system is characterized by comprising a gas-liquid mixer, a gas-liquid mixing and conveying pump, a flash tank and a buffer tank, wherein a pipeline for conveying triethylene glycol rectifying tower tail gas is communicated with one inlet of the gas-liquid mixer, an outlet of the gas-liquid mixer is communicated with the gas-liquid mixing and conveying pump, the gas-liquid mixing and conveying pump is communicated with the flash tank, the bottom of the flash tank is communicated with the other inlet of the gas-liquid mixer through the pipeline,

The flash tank is communicated with the buffer tank through a pipeline, the buffer tank is provided with an output pipeline for outputting gas, the output pipeline is used for conveying the gas to the reboiler, and the buffer tank is also provided with an input pipeline for conveying combustion gas, and the input pipeline is used for inputting the combustion gas into the buffer tank.

2. The rectifying column tail gas treatment system according to claim 1, further comprising a controller, wherein the flash tank and/or the buffer tank are provided with a pressure sensor, the input pipeline is provided with a control valve, the pressure sensor and the control valve are electrically connected with the controller, respectively, and the controller is used for controlling the control valve.

3. The rectifying column tail gas treatment system of claim 1, wherein said controller employs a PLC and/or said control valve employs a solenoid valve.

4. The rectifying column tail gas treatment system of claim 1, further comprising a triethylene glycol input conduit in communication with said flash tank, said triethylene glycol input conduit further provided with a valve.

5. The rectifying column tail gas treatment system of claim 1, wherein the gas-liquid mixing pump is in communication with the flash tank via a conduit, and wherein the conduit is not configured with a cooler.

6. The rectifying column tail gas treatment system of claim 5, further comprising a circulating liquid output pipeline, wherein one end of the circulating liquid output pipeline is communicated with a pipeline between the gas-liquid mixing pump and the flash tank, the other end of the circulating liquid output pipeline is used for communicating with the triethylene glycol rectifying column, the pipeline is arranged at a valve, and the circulating liquid output pipeline is also provided with the valve.

7. The rectifying column tail gas treatment system of any one of claims 1-6, wherein the top of the flash tank is in communication with the top of the buffer tank through a conduit;

and/or the output pipeline is communicated with the top of the buffer tank;

and/or the input pipeline is communicated with the top of the buffer tank.

8. The rectifying column tail gas treatment system of any of claims 1-6, wherein the buffer tank has a volume that is less than the volume of the flash tank.

9. The rectifying column tail gas treatment system according to any one of claims 1 to 6, further comprising a gas-liquid separator for performing gas-liquid separation, an inlet of the gas-liquid separator being for inputting tail gas, a gas phase outlet of the gas-liquid separator being in communication with said gas-liquid mixer through a pipe, a liquid phase outlet of the gas-liquid separator being provided with a waste water pipe, said waste water pipe being provided with a drain pump.

10. The rectifying column tail gas treatment system of claim 9, further comprising a cooler having one port for inputting tail gas and another port in communication with the gas-liquid separator, the cooler being for condensing tail gas.