Natural gas decarbonization system

Abstract

The utility model provides a natural gas decarburization system, which comprises an absorption tower with a gas inlet at the lower part, a liquid inlet at the upper part, a gas outlet at the top and a liquid outlet at the bottom; the gas inlet is used for receiving raw material gas, the liquid inlet is used for receiving alcohol amine liquid, the raw material gas is arranged from bottom to top in the absorption tower, the alcohol amine liquid is arranged from top to bottom in the absorption tower, the liquid outlet is used for outputting rich liquid, and the gas outlet is used for outputting purified gas outwards; the cooler is arranged at the upper part in the absorption tower and is positioned below the gas outlet; the upper part of the regeneration tower is provided with a liquid inlet communicated with the liquid outlet to receive rich liquid, the bottom of the regeneration tower is communicated with the liquid inlet, and the top of the regeneration tower is provided with a gas output port for outputting carbon dioxide; the reboiler is arranged at the lower part in the regeneration tower and is used for heating liquid in the regeneration tower to release carbon dioxide and obtain barren liquor; and the condenser is arranged at the upper part in the regeneration tower and is positioned below the gas output port so as to reduce the temperature of the carbon dioxide gas.

Description

Technical Field

[0001] This utility model relates to the field of new energy technology, and in particular to a natural gas decarbonization system. Background Technology

[0002] Syngas and natural gas extracted from formations typically contain some acidic gases such as CO2. Specifically, according to requirements for natural gas, the CO2 content must be less than 3% (mole%) before it can be supplied to residential users. Furthermore, to prevent freezing blockage caused by low CO2 levels, the CO2 content in natural gas used to produce LNG must be as low as 50 ppm; therefore, natural gas with high CO2 content requires decarbonization treatment.

[0003] Currently, commonly used decarbonization methods both domestically and internationally include cryogenic separation, membrane separation, adsorption separation, solvent absorption, and combined methods. Cryogenic separation is suitable for applications with high acid gas content but low purification requirements, but its complex process and significant temperature drops lead to high energy consumption. Membrane separation is suitable for the rough removal of acid gas and water from high-carbon natural gas. Industrially, membrane separation is typically used first for rough removal, followed by chemical solvent extraction for fine removal, achieving high purification levels and being relatively economical. While membrane separation offers advantages such as low energy consumption, small footprint, convenient maintenance, high efficiency, and environmental friendliness, it suffers from a relatively high hydrocarbon loss rate. Adsorption separation is suitable for applications with small throughput, low carbon content, and high purification requirements. Solvent absorption remains one of the most mature and widely used decarbonization methods. Solvent absorption is further divided into chemical absorption, physical absorption, and mixed solvent methods. Among these, the amine method is the most widely used. However, current amine methods involve numerous devices and structures with low integration and complex process control. Utility Model Content

[0004] The purpose of this invention is to provide a natural gas decarbonization system to solve the problems of the prior art.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a natural gas decarbonization system, comprising:

[0006] An absorption tower has an air inlet at the bottom, a liquid inlet at the top, an air outlet at the top, and a liquid outlet at the bottom. The air inlet receives raw gas, and the liquid inlet receives amine liquid. The raw gas flows from bottom to top in the absorption tower, and the amine liquid flows from top to bottom. The amine liquid absorbs carbon dioxide from the raw gas to form a rich liquid. The liquid outlet is used to output the rich liquid, and the air outlet is used to output purified gas.

[0007] A cooler is disposed in the upper part of the absorption tower and located below the gas outlet;

[0008] The regeneration tower has an inlet at the top that is connected to the outlet to receive rich liquid, a bottom that is connected to the inlet, and a gas outlet at the top that outputs carbon dioxide.

[0009] A reboiler, located in the lower part of the regeneration tower, is used to heat the liquid in the regeneration tower to release carbon dioxide and obtain lean liquid;

[0010] A condenser is disposed in the upper part of the regeneration tower and below the gas outlet to reduce the temperature of the carbon dioxide gas.

[0011] In one embodiment, the natural gas decarbonization system further includes a heat exchanger, which includes a heat source channel and a cold source channel that are independent of each other and capable of heat exchange. The two ends of the cold source channel are respectively connected to the liquid outlet and the liquid inlet, and the inlet of the heat source channel is respectively connected to the bottom of the regeneration tower and the liquid inlet.

[0012] In one embodiment, the heat exchanger is a plate heat exchanger.

[0013] In one embodiment, the natural gas decarbonization system further includes a buffer tank, a booster pump, and a cooler, which are sequentially disposed between the bottom of the regeneration tower and the inlet of the absorption tower. The buffer tank is used to receive the lean liquid output from the regeneration tower, the booster pump is used to pressurize the lean liquid, and the cooler is used to cool the pressurized lean liquid.

[0014] In one embodiment, the cooler is also connected to the buffer tank, and the cooled lean liquid is transported to the buffer tank for storage.

[0015] A filter is provided between the cooler and the buffer tank;

[0016] The number of booster pumps is two, and the two booster pumps are connected in parallel.

[0017] In one embodiment, the outlet of the absorption tower is provided with an outlet pipeline, the outlet pipeline is equipped with an outlet control valve, the absorption tower is equipped with a level gauge, and the natural gas decarbonization system includes a control module. The control module is communicatively connected to the level gauge and the outlet control valve, and is used to control the opening and closing of the outlet control valve according to the signal of the level gauge.

[0018] In one embodiment, a return liquid pipeline is provided between the bottom of the regeneration tower and the inlet of the absorption tower. The return liquid pipeline is equipped with a return liquid control valve. A liquid level monitor is provided inside the regeneration tower. The natural gas decarbonization system includes a control module. The control module is communicatively connected to the liquid level monitor and the return liquid control valve and is used to control the opening and closing of the return liquid control valve according to the signal from the liquid level monitor.

[0019] In one embodiment, the cooler includes a lower tube sheet and an upper tube sheet connected to the inner wall of the absorption tower, and a plurality of heat exchange tubes extending vertically. The lower tube sheet and the upper tube sheet are arranged parallel to each other vertically and together with the absorption tower to form a receiving space. The lower tube sheet is spaced above the liquid inlet, and the upper tube sheet is spaced below the gas outlet and spaced above the lower tube sheet. The heat exchange tubes are used to connect the spaces above and below the receiving space. The side wall of the absorption tower is provided with an inlet and an outlet communicating with the receiving space. The inlet is used for the cooling medium to enter, and the outlet is used for the cooling medium to exit after heat absorption.

[0020] The cooler includes a downcomer whose top extends upward from the upper tube sheet and whose bottom extends downward to the bottom of the absorption tower.

[0021] In one embodiment, the condenser includes a lower partition and an upper partition connected to the inner wall of the regeneration tower, and a plurality of vertically extending flow pipes. The lower partition and the upper partition are arranged vertically parallel and spaced apart to enclose a receiving space together with the regeneration tower. The lower partition is spaced above the liquid inlet, and the upper partition is spaced below the gas outlet of the regeneration tower and spaced above the lower partition. The flow pipes are used to connect the spaces above and below the receiving space. The side wall of the regeneration tower is provided with an inlet and an outlet communicating with the receiving space. The inlet is used for the cooling medium to enter, and the outlet is used for the cooling medium to exit after heat absorption.

[0022] The condenser includes a condensate tube, the top of which extends upward beyond the upper baffle and the bottom of which extends downward to the bottom of the regeneration tower.

[0023] In one embodiment, the cooler is a circulating water cooler, the condenser is a circulating water condenser, and the heat source for the reboiler is heat transfer oil.

[0024] The natural gas decarbonization system includes a skid, on which the absorption tower and the regeneration tower are mounted.

[0025] As can be seen from the above technical solution, this utility model has at least the following advantages and positive effects:

[0026] This utility model's natural gas decarbonization system integrates the cooler and absorption tower into a single design, and integrates the condenser, reboiler, and regeneration tower into a single design. This reduces the number of devices in the entire system, as well as the number of external pipes and fittings. It has a high degree of integration, simpler process control points, and is more convenient to operate and use, making it more in line with the characteristics of skid-mounted devices.

[0027] The equipment has a high degree of integration, which is beneficial for skid-mounted construction and subsequent use. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the natural gas decarbonization system in this utility model.

[0029] The annotations in the attached figures are explained as follows:

[0030] 11. Absorber; 12. Cooler; 13. Regeneration tower; 14. Condenser; 15. Reboiler; 16. Heat exchanger; 17. Buffer tank; 18. Booster pump; 19. Cooler; 20. Filter; 21. Discharge control valve; 22. Return control valve. Detailed Implementation

[0031] Although the present invention can be readily embodied in various forms, only some specific embodiments are shown in the accompanying drawings and will be described in detail in this specification. It is understood that this specification should be regarded as an exemplary illustration of the principles of the present invention and is not intended to limit the present invention to what is described herein.

[0032] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present invention, and does not imply that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0033] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various elements of this invention are relative rather than absolute. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, these directional indications also change accordingly.

[0034] This application provides a natural gas decarbonization system, mainly used for decarbonizing natural gas.

[0035] This natural gas decarbonization system can purify the carbon dioxide content in natural gas or syngas to below 50 ppm or other customized ranges as needed, with good purification effect.

[0036] See Figure 1 The natural gas decarbonization system includes an absorption tower 11, a cooler 12, a regeneration tower 13, a condenser 14, and a reboiler 15. The cooler 12 is located inside the absorption tower 11, achieving an integrated design between the two. The condenser 14 and the reboiler 15 are located inside the regeneration tower 13, achieving an integrated design for all three. This reduces the number of devices in the entire system, reduces the number of external pipes and fittings, has a high degree of integration, simplifies process control points, makes operation and use more convenient, and is more in line with the characteristics of skid-mounted units.

[0037] The absorption tower 11 has a vertically extending structure and an internal space. The absorption tower 11 has an air inlet at the bottom, a liquid inlet at the top, an air outlet at the top, and a liquid outlet at the bottom.

[0038] The air inlet is used to receive raw material gas, and the liquid inlet is used to receive amine liquid. The liquid outlet is used to output rich liquid, and the air outlet is used to output purified gas.

[0039] The feedstock gas can be natural gas or syngas.

[0040] Alkylamine can be methyl diethanolamine (MDEA).

[0041] The raw gas enters the absorption tower 11 through the inlet and flows upward within the tower. The amine liquid flows downward within the absorption tower 11, absorbing carbon dioxide from the raw gas to form a rich liquid.

[0042] It should be noted that when the alcoholamine liquid in the absorption tower 11 comes into contact with the raw gas containing carbon dioxide, the carbon dioxide reacts chemically with the alcoholamine liquid and is absorbed into the solution. This solution is called the rich solution. The rich solution, after releasing carbon dioxide, becomes the lean solution.

[0043] The components in the raw gas that are not absorbed by the amine liquid are cooled by cooler 12 and discharged out through the outlet. The discharged purified gas enters the next process section.

[0044] Cooler 12 is located in the upper part of the absorption tower 11, below the gas outlet. Therefore, the purified gas is cooled by cooler 12 before being output. That is, cooler 12 is used to provide cooling capacity to cool the temperature of the purified gas.

[0045] Specifically, the cooler 12 includes a lower tube sheet and an upper tube sheet connected to the inner wall of the absorption tower 11, and multiple heat exchange tubes extending vertically. The lower and upper tube sheets are arranged vertically parallel and spaced apart, forming a containment space together with the absorption tower 11. The lower tube sheet is spaced above the liquid inlet, and the upper tube sheet is spaced below the gas outlet and spaced above the lower tube sheet. The heat exchange tubes connect the upper and lower spaces of the containment space. The side wall of the absorption tower 11 has an inlet and an outlet communicating with the containment space. The inlet is for the cooling medium to enter, and the outlet is for the cooling medium to exit after heat absorption.

[0046] That is, after the raw material gas is purified by the amine liquid, the remaining gas enters the heat exchange tube and exchanges heat with the cooling medium entering the containment space to cool down. Then it flows out through the heat exchange tube and is finally output to the outside through the outlet.

[0047] In this embodiment, multiple through holes are provided on both the lower tube sheet and the upper tube sheet. The outer peripheral wall of the heat exchange tube is sealed to the inner peripheral wall of the through hole, thereby achieving the independence of the housing space and connecting the two spaces located above and below the housing space.

[0048] The cooler includes a downcomer, the top of which extends upwards out of the upper tube sheet and the bottom of which extends downwards to the bottom of the absorption tower 11. The downcomer is used to receive the liquid formed after the cooler body is cooled and to allow the liquid to flow to the bottom of the absorption tower 11.

[0049] In other embodiments, the bottom of the downcomer extends below the liquid level inside the absorption tower 11, so that the liquid falls directly below the liquid level and avoids dripping directly onto the liquid surface.

[0050] In this embodiment, the cooler 12 is a circulating water cooler.

[0051] The regeneration tower 13 has a vertically extending structure and an internal space. The upper part of the regeneration tower 13 is provided with an inlet that communicates with the outlet to receive rich liquid, the bottom is connected to the inlet, and the top is provided with a gas outlet for discharging carbon dioxide.

[0052] The bottom of the regeneration tower 13 is provided with a drain port, which is connected to the inlet port to send the regenerated lean liquid into the absorption tower 11.

[0053] The reboiler 15 is located in the lower part of the regeneration tower 13 and is used to heat the liquid in the regeneration tower 13 to release carbon dioxide and obtain lean liquid.

[0054] Specifically, the heat source for the reboiler 15 is heat transfer oil. The heat transfer oil is supplied by a gas-fired heat transfer oil furnace. By controlling the temperature of the heat transfer oil and appropriately increasing the heat exchange area of ​​the reboiler 15, the wall temperature of the heat exchange tubes of the reboiler 15 is kept at a low level to prevent the degradation of the amine liquid.

[0055] The reboiler 15 includes a first baffle and a second baffle connected to the inner wall of the regeneration tower 13, as well as a plurality of vertically extending conductive pipes. The tube plates of the first and second baffles are arranged vertically parallel and spaced apart to enclose a receiving space together with the regeneration tower 13. The first baffle is spaced above the drain port, and the second baffle is spaced above the first baffle. The conductive pipes are used to connect the upper and lower receiving spaces. The side wall of the regeneration tower 13 is provided with an inlet and an outlet communicating with the receiving space. The inlet is used for the heat source medium to enter, and the outlet is used for the heat source medium to exit after releasing heat.

[0056] That is, the rich liquid entering the regeneration tower 13 releases carbon dioxide after being heated. And since the reboiler 15 is located at the bottom of the regeneration tower 13, during the heating process, the gas at the bottom of the regeneration tower 13 rises and forms a secondary stripping effect on the rich liquid at the top of the regeneration tower 13, further promoting the release of carbon dioxide.

[0057] The condenser 14 is located in the upper part of the regeneration tower 13, below the gas outlet. The condenser 14 is used to reduce the temperature of carbon dioxide. That is, the carbon dioxide released after heating the rich liquid in the regeneration tower 13 is cooled by the condenser 14 before being discharged.

[0058] Among them, carbon dioxide can be released directly into the air at high points.

[0059] Specifically, the condenser 14 includes a lower baffle and an upper baffle connected to the inner wall of the regeneration tower 13, as well as a plurality of vertically extending flow pipes. The lower and upper baffles are arranged vertically parallel and spaced apart, forming a containment space together with the regeneration tower 13. The lower baffles are spaced above the liquid inlet, and the upper baffles are spaced below the gas outlet of the regeneration tower 13 and spaced above the lower baffles. The flow pipes are used to connect the upper and lower spaces of the containment space. The side wall of the regeneration tower 13 is provided with an inlet and an outlet communicating with the containment space. The inlet is used for the cooling medium to enter, and the outlet is used for the cooling medium to exit after heat absorption.

[0060] That is, after the rich liquid is released, the gas enters the flow pipe and exchanges heat with the cooling medium entering the containment space to cool down. Then it flows out through the flow pipe and is finally output to the outside through the gas phase outlet.

[0061] In this embodiment, multiple through holes are provided on both the lower and upper partitions. The outer peripheral wall of the flow tube is sealed to the inner peripheral wall of the through hole, thereby achieving the independence of the accommodating space and connecting the two spaces located above and below the accommodating space.

[0062] The condenser 14 includes a condensate pipe, the top of which extends upward beyond an upper baffle plate, and the bottom of which extends downward to the bottom of the regeneration tower 13. The condensate pipe is used to receive the liquid formed after the condenser body is cooled, and to allow the liquid to flow through the condensate pipe to the bottom of the regeneration tower 13.

[0063] In this embodiment, the bottom of the condensate tube is located above the reboiler 15.

[0064] Condenser 14 is a circulating water condenser.

[0065] The natural gas decarbonization system also includes a heat exchanger 16. The heat exchanger 16 includes a heat source channel and a cold source channel that are independent of each other and capable of heat exchange. The two ends of the cold source channel are connected to the liquid outlet and the liquid inlet, respectively, and the inlet of the heat source channel is connected to the bottom of the regeneration tower 13 and the liquid inlet, respectively.

[0066] That is, the rich liquid output from the absorption tower 11 and the lean liquid output from the regeneration tower 13 exchange heat in the heat exchanger 16, allowing the rich liquid to absorb heat from the lean liquid and heat up before entering the regeneration tower 13. This reduces the heat required for the rich liquid to release carbon dioxide, thus reducing the heat load on the reboiler 15 and consequently reducing the energy consumption of the entire system. The lean liquid, after releasing heat, enters the absorption tower 11, reducing the cooling capacity required by the cooler 12 within the absorption tower 11, further reducing the energy consumption of the entire system.

[0067] Specifically, after the rich liquid absorbs heat from the lean liquid in the heat exchanger 16, its temperature can rise to 90-99°C.

[0068] Among them, heat exchanger 16 is a plate heat exchanger.

[0069] The absorber 11 has an outlet pipe. An outlet control valve 21 is installed on the outlet pipe. A level gauge is installed inside the absorber 11. The natural gas decarbonization system includes a control module, which is communicatively connected to the level gauge and the outlet control valve 21. The control module controls the opening and closing of the outlet control valve 21 based on signals from the level gauge. Specifically, the level gauge or control module has preset low and high levels. When the level detected by the level gauge reaches the low level due to the outflow of rich liquid through the outlet, the control module closes the outlet control valve 21, preventing the rich liquid from being output from the absorber 11. When the level detected by the level gauge reaches the high level, the control module opens the outlet control valve 21 to continue supplying rich liquid.

[0070] Specifically, the liquid outlet control valve 21 is located between the liquid outlet and the heat exchanger 16.

[0071] The natural gas decarbonization system also includes a buffer tank 17, a booster pump 18, and a cooler 19, which are sequentially arranged between the bottom of the regeneration tower 13 and the inlet of the absorption tower 11. The buffer tank 17 is used to receive the lean liquid output from the regeneration tower 13, the booster pump 18 is used to pressurize the lean liquid, and the cooler 19 is used to cool the pressurized lean liquid.

[0072] Specifically, buffer tank 17 is located at the outlet of the heat source channel of heat exchanger 16, connecting buffer tank 17 to the bottom of regeneration tower 13. Cooler 19 is connected to the liquid inlet of absorption tower 11, thereby transporting the cooled lean liquid into absorption tower 11.

[0073] In this embodiment, there are two booster pumps 18, which are connected in parallel. That is, one booster pump 18 is in use and the other is on standby.

[0074] The cooler 19 is also connected to the buffer tank 17, which delivers the cooled lean liquid to the buffer tank 17 for storage. Specifically, a regulating valve directs a portion of the lean liquid into the absorption tower 11 and a portion into the buffer tank 17. In this embodiment, most of the lean liquid cooled by the cooler 19 enters the absorption tower 11, and a small portion enters the buffer tank 17. For example, 90% enters the absorption tower 11 and 10% enters the buffer tank 17.

[0075] A filter 20 is provided between the cooler 19 and the buffer tank 17 to filter the lean liquid entering the buffer tank 17.

[0076] A return liquid pipeline is installed between the bottom of the regeneration tower 13 and the inlet of the absorption tower 11. The return liquid pipeline is equipped with a return liquid control valve 22. A liquid level monitor is installed inside the regeneration tower 13. The natural gas decarbonization system includes a control module, which is communicatively connected to the liquid level monitor and the return liquid control valve 22, and is used to control the opening and closing of the return liquid control valve 22 based on the signal from the liquid level monitor.

[0077] Specifically, the level monitor or control module has preset low and high levels. When the level detected by the level monitor reaches the low level due to the outflow of lean liquid, the control module controls the return control valve 22 to close, thus preventing the outflow of lean liquid from the regeneration tower 13. When the level detected by the level monitor reaches the high level, the control module controls the return control valve 22 to open, allowing the lean liquid to continue to be outflowed.

[0078] In this embodiment, the return liquid control valve 22 is installed on the pipeline between the heat exchanger 16 and the buffer tank 17.

[0079] The natural gas decarbonization system includes a skid, on which an absorption tower 11 and a regeneration tower 13 are mounted.

[0080] The heat exchanger 16, buffer tank 17, booster pump 18, cooler 19 and filter 20 are all mounted on the skid.

[0081] The working principle of this natural gas decarbonization system is as follows:

[0082] The raw gas enters the absorption tower 11 through the inlet and flows upward within the tower. The amine liquid enters the absorption tower 11 through the liquid inlet and flows downward within the tower. The raw gas and the amine liquid come into countercurrent contact, with the amine liquid absorbing carbon dioxide from the raw gas to purify it, resulting in a rich liquid and purified gas.

[0083] The purified gas is cooled down by the cooler 12 inside the absorption tower 11 and then output to the outside through the outlet.

[0084] The rich liquid is output from the outlet of the absorption tower 11, passes through the heat exchanger 16 and exchanges heat with the lean liquid output from the regeneration tower 13 in the heat exchanger 16. After absorbing heat, the rich liquid enters the upper part of the regeneration tower 13.

[0085] The rich liquor releases carbon dioxide through heating in the reboiler 15 within the regeneration tower 13. The released carbon dioxide flows upwards, is condensed in the condenser 14, and is then discharged outwards through the gas outlet.

[0086] The lean liquor that releases carbon dioxide is output from the bottom of regeneration tower 13 and exchanges heat with the rich liquor in heat exchanger 16. The cooled lean liquor enters buffer tank 17, and then is pressurized by booster pump 18 and cooled by cooler 19 before entering absorption tower 11. The lean liquor output from cooler 19 can be partially filtered and stored in buffer tank 17.

[0087] The amine solution in the absorption tower 11 is circulated and reused in both the absorption tower 11 and the regeneration tower 13.

[0088] In summary, this natural gas decarbonization system has the following advantages:

[0089] The integrated design of cooler 12 and absorption tower 11, as well as condenser 14, reboiler 15 and regeneration tower 13, reduces the number of equipment in the entire system, the number of external pipes and fittings, and has a high degree of integration. The process control points are simpler, making it more convenient to operate and use, and is more in line with the characteristics of skid-mounted devices.

[0090] The equipment has a high degree of integration, which is beneficial for skid-mounted construction and subsequent use.

[0091] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A natural gas decarbonization system, characterized in that, include: An absorption tower has an air inlet at the bottom, a liquid inlet at the top, an air outlet at the top, and a liquid outlet at the bottom. The air inlet receives raw gas, and the liquid inlet receives amine liquid. The raw gas flows from bottom to top in the absorption tower, and the amine liquid flows from top to bottom. The amine liquid absorbs carbon dioxide from the raw gas to form a rich liquid. The liquid outlet is used to output the rich liquid, and the air outlet is used to output purified gas. A cooler is disposed in the upper part of the absorption tower and located below the gas outlet; The regeneration tower has an inlet at the top that is connected to the outlet to receive rich liquid, a bottom that is connected to the inlet, and a gas outlet at the top that outputs carbon dioxide. A reboiler, located in the lower part of the regeneration tower, is used to heat the liquid in the regeneration tower to release carbon dioxide and obtain lean liquid; A condenser is disposed in the upper part of the regeneration tower and below the gas outlet to reduce the temperature of the carbon dioxide gas.

2. The natural gas decarbonization system according to claim 1, characterized in that, The natural gas decarbonization system also includes a heat exchanger, which includes an independent heat source channel and a cold source channel capable of heat exchange. The two ends of the cold source channel are respectively connected to the liquid outlet and the liquid inlet, and the inlet of the heat source channel is respectively connected to the bottom of the regeneration tower and the liquid inlet.

3. The natural gas decarbonization system according to claim 2, characterized in that, The heat exchanger is a plate heat exchanger.

4. The natural gas decarbonization system according to claim 1, characterized in that, The natural gas decarbonization system also includes a buffer tank, a booster pump, and a cooler, which are sequentially arranged between the bottom of the regeneration tower and the inlet of the absorption tower. The buffer tank is used to receive the lean liquid output from the regeneration tower, the booster pump is used to pressurize the lean liquid, and the cooler is used to cool the pressurized lean liquid.

5. The natural gas decarbonization system according to claim 4, characterized in that, The cooler is also connected to the buffer tank, and the cooled lean liquid is transported to the buffer tank for storage. A filter is provided between the cooler and the buffer tank; The number of booster pumps is two, and the two booster pumps are connected in parallel.

6. The natural gas decarbonization system according to claim 1, characterized in that, The absorption tower is provided with an outlet pipeline, which is equipped with an outlet control valve. The absorption tower is equipped with a level gauge. The natural gas decarbonization system includes a control module, which is communicatively connected to the level gauge and the outlet control valve. The control module is used to control the opening and closing of the outlet control valve based on the signal from the level gauge.

7. The natural gas decarbonization system according to claim 1, characterized in that, A return liquid pipeline is provided between the bottom of the regeneration tower and the inlet of the absorption tower. The return liquid pipeline is equipped with a return liquid control valve. A liquid level monitor is provided inside the regeneration tower. The natural gas decarbonization system includes a control module. The control module is communicatively connected to the liquid level monitor and the return liquid control valve and is used to control the opening and closing of the return liquid control valve based on the signal from the liquid level monitor.

8. The natural gas decarbonization system according to claim 1, characterized in that, The cooler includes an upper tube sheet and a lower tube sheet connected to the inner wall of the absorption tower, and a plurality of heat exchange tubes extending vertically. The lower tube sheet and the upper tube sheet are arranged parallel to each other vertically and together with the absorption tower to form a receiving space. The lower tube sheet is spaced above the liquid inlet, and the upper tube sheet is spaced below the gas outlet and spaced above the lower tube sheet. The heat exchange tubes are used to connect the upper and lower spaces of the receiving space. The side wall of the absorption tower is provided with an inlet and an outlet communicating with the receiving space. The inlet is used for the cooling medium to enter, and the outlet is used for the cooling medium to exit after heat absorption. The cooler includes a downcomer, the top of which extends upward out of the upper tube sheet and the bottom of which extends downward to the bottom of the absorption tower.

9. The natural gas decarbonization system according to claim 1, characterized in that, The condenser includes a lower partition and an upper partition connected to the inner wall of the regeneration tower, and a plurality of vertically extending flow pipes. The lower partition and the upper partition are arranged vertically parallel and spaced apart to enclose a accommodating space together with the regeneration tower. The lower partition is spaced above the liquid inlet, and the upper partition is spaced below the gas outlet of the regeneration tower and spaced above the lower partition. The flow pipes are used to connect the spaces above and below the accommodating space. The side wall of the regeneration tower is provided with an inlet and an outlet communicating with the accommodating space. The inlet is used for the cooling medium to enter, and the outlet is used for the cooling medium to exit after heat absorption. The condenser includes a condensate tube, the top of which extends upward beyond the upper baffle and the bottom of which extends downward to the bottom of the regeneration tower.

10. The natural gas decarbonization system according to claim 1, characterized in that, The cooler is a circulating water cooler, the condenser is a circulating water condenser, and the heat source for the reboiler is heat transfer oil. The natural gas decarbonization system includes a skid, on which the absorption tower and the regeneration tower are mounted.

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