Natural gas amine liquid decarburization process device

Abstract

The present invention discloses a natural gas amine liquid decarburization process apparatus, which comprises: a decarburization device, which comprises an absorption tower and a rectification tower, and the absorption tower is communicated with the rectification tower; the heat exchange equipment comprises an air inlet pipe, a preheater, a reheater, a first control pipeline and a second control pipeline, the outlet end of the air inlet pipe communicates with an air inlet of the preheater and an air inlet of the reheater, and first electromagnetic valves are arranged at the air inlet of the preheater and the air inlet of the reheater correspondingly; a second electromagnetic valve located between the two first electromagnetic valves is arranged on the air inlet pipe; the first control pipeline is respectively communicated with the preheater, the gas inlet pipe and the second control pipeline, the second control pipeline is communicated with the absorption tower and the reheater, and feed gas enters from the gas inlet pipe and flows into the absorption tower through the preheater and / or the reheater. Therefore, waste heat generated by the absorption tower and the rectifying tower can be reasonably recycled and used as a heat source to heat the raw material gas, an additional heating source does not need to be arranged, and the cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas purification, and in particular to a natural gas amine liquid decarbonization process device. Background Art

[0002] Traditional amine-based natural gas decarbonization processes have specific requirements for the feed gas's inlet temperature, which ranges from 40°C to 50°C. Because natural gas temperatures often struggle to reach this temperature during extraction and transportation, additional heating measures are required before the feed gas enters the decarbonization unit to ensure it meets the inlet temperature requirements of traditional amine-based decarbonization processes.

[0003] Currently, in practical applications, additional heating sources are often used to heat the raw gas. The heating sources used can be electric heating devices or steam heating devices. These heating sources heat the natural gas to an appropriate temperature range of 40-50°C, thereby ensuring the smooth progress of the decarbonization process.

[0004] However, setting up an additional heating source not only increases the purchase cost, but also significantly increases the operating cost due to continuous energy consumption. Summary of the Invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, one purpose of the present invention is to propose a natural gas amine liquid decarbonization process device that can reasonably recycle and utilize the waste heat generated by the absorption tower and the distillation tower as a heat source to heat the raw gas without setting up an additional heating source, thereby greatly reducing the purchase cost and operating cost.

[0007] To achieve the above-mentioned purpose, the present invention proposes a natural gas amine liquid decarbonization process device, comprising: decarbonization equipment, including an absorption tower and a distillation tower, the absorption tower and the distillation tower being connected; heat exchange equipment, including an air inlet pipe, a preheater, a reheater, a first control pipeline, and a second control pipeline, wherein the outlet end of the air inlet pipe is respectively connected to the air inlet of the preheater and the air inlet of the reheater, and the air inlet of the preheater and the air inlet of the reheater are respectively provided with a first solenoid valve, and the air inlet pipe is provided with a second solenoid valve located between the two first solenoid valves; the first control pipeline is respectively connected to the preheater, the air inlet pipe and the second control pipeline, and the The first control pipeline is configured to control the on-off and flow path of its own pipeline, the second control pipeline connects the absorption tower and the reheater, and the second control pipeline is configured to control the on-off and flow path of its own pipeline, wherein the raw gas enters from the air inlet pipe and flows into the absorption tower through the preheater and / or the reheater; wherein the absorption tower is connected to the preheater to supply the heating medium generated by the absorption tower into the preheater to heat the raw gas flowing through the preheater, and the distillation tower is connected to the reheater to supply the tail gas generated by the distillation tower into the reheater to heat the raw gas or the preheated raw gas flowing through the reheater.

[0008] The natural gas amine liquid decarbonization process apparatus of the present invention, by coupling heat exchange equipment with the decarbonization unit, can adapt to the natural gas pretreatment requirements under highly fluctuating operating conditions. By dynamically switching heating paths, it effectively utilizes waste heat from the absorption and distillation towers. Compared to the traditional method of heating the feed gas with additional heating devices, this solution can rationally recycle the waste heat generated by the absorption and distillation towers as a heat source to heat the feed gas, eliminating the need for additional heating sources and significantly reducing acquisition and operating costs.

[0009] In addition, the natural gas amine liquid decarbonization process device proposed in the application may also have the following additional technical features:

[0010] Specifically, the intake pipe, the first control pipeline and the second control pipeline are each provided with a temperature sensor for detecting the temperature of the raw gas in the intake pipe, the first control pipeline and the second control pipeline, and the temperature sensor, the first solenoid valve and the second solenoid valve, the first control pipeline and the second control pipeline are respectively connected to an external controller.

[0011] Specifically, the first control pipeline includes a first connecting pipe and two third solenoid valves, the first connecting pipe has an air intake pipeline and two air outlet branches, the two air outlet branches are respectively connected to the air intake pipeline, wherein the air intake pipeline is connected to the preheater, one air outlet branch is connected to the air intake pipe, and the other air outlet branch is connected to the second control pipeline, and the third solenoid valves are respectively provided on the two air outlet branches.

[0012] Specifically, the second control pipeline includes a second connecting pipe and a fourth solenoid valve, wherein one end of the second connecting pipe is connected to the reheater, the other end of the second connecting pipe is connected to the absorption tower, one of the gas outlet branches is connected to the second connecting pipe, and the third solenoid valve and the fourth solenoid valve are respectively connected to an external controller.

[0013] Specifically, it also includes a third connecting pipe, a fourth connecting pipe, a separator, a fifth solenoid valve and a sixth solenoid valve, wherein,

[0014] The third connecting pipe is respectively connected to the absorption tower, the preheater and the fourth connecting pipe. The branch line of the third connecting pipe connected to the preheater is provided with the fifth solenoid valve. The branch line of the third connecting pipe connected to the fourth connecting pipe is provided with the fifth solenoid valve.

[0015] The fourth communicating pipe is connected to the preheater and the separator respectively. The sixth solenoid valve is provided on the fourth communicating pipe and is arranged adjacent to the preheater. The fifth solenoid valve and the sixth solenoid valve are connected to an external controller respectively.

[0016] Specifically, it also includes a flash tank, a first filter, and a heat exchanger, wherein the absorption tower, the flash tank, the first filter, the heat exchanger and the distillation tower are sequentially connected in series.

[0017] Specifically, it also includes a reboiler, a buffer tank, a first air cooler and a circulation pump, wherein the absorption tower includes a liquid phase port and a gas phase port, wherein the reboiler is connected to the gas phase port, and is used to discharge the reboiled steam into the distillation tower, and the gas phase port, the reboiler, the buffer tank, the heat exchanger, the first air cooler, the circulation pump and the absorption tower are connected in series in sequence.

[0018] Specifically, it also includes a fifth connecting pipeline, a sixth connecting pipeline, a seventh solenoid valve, and an eighth solenoid valve, wherein:

[0019] The fifth communicating line is connected to the reheater and the sixth communicating line respectively, the seventh solenoid valve is provided on the branch line between the fifth communicating line and the reheater, and the seventh solenoid valve is provided on the branch line between the fifth communicating line and the sixth communicating line;

[0020] One end of the sixth communicating pipe is connected to the reheater, and the other end of the sixth communicating pipe is connected to the distillation tower, and the eighth solenoid valve is provided on the sixth communicating pipe, and the eighth solenoid valve is arranged adjacent to the reheater, and the seventh solenoid valve and the eighth solenoid valve are respectively connected to an external controller.

[0021] Specifically, it further includes a second air cooler, a reflux tank and a reflux pump, wherein the sixth connecting pipeline is used to sequentially connect the second air cooler, the reflux tank, the reflux pump and the distillation tower in series.

[0022] Specifically, a second filter is provided on the second connecting pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 Schematic diagram of the structure of a natural gas amine liquid decarbonization process device according to one embodiment of the present invention.

[0026] As shown in the figure:

[0027] 10. Absorption tower; 11. Distillation tower; 12. Flash tank; 13. First filter; 14. Heat exchanger; 15. Reboiler; 16. Buffer tank; 17. First air cooler; 18. Circulation pump; 19. Second filter;

[0028] 20. Intake pipe; 21. Preheater; 22. Reheater; 23. First control line; 24. Second control line; 25. First solenoid valve; 26. Second solenoid valve; 27. Temperature sensor; 28. Third connecting pipe; 29. ​​Fourth connecting pipe; 30. Separator; 31. Fifth solenoid valve; 32. Sixth solenoid valve; 33. Fifth connecting line; 34. Sixth connecting line; 35. Seventh solenoid valve; 36. Eighth solenoid valve; 37. Second air cooler; 38. Reflux tank; 39. Reflux pump; 230. First connecting pipe; 231. Third solenoid valve; 240. Second connecting pipe; 241. Fourth solenoid valve. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] The natural gas amine liquid decarbonization process device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the natural gas amine liquid decarbonization process device according to the embodiment of the present invention may include decarbonization equipment and heat exchange equipment.

[0033] The decarbonization equipment comprises an absorption tower 10 and a distillation tower 11, which are interconnected. The absorption tower 10 utilizes a multi-stage absorption structure. Feed gas enters the tower from the bottom and comes into contact with the circulating lean amine solution sprayed from the top of the tower in the packing section, effectively removing carbon dioxide from the feed gas through physical absorption. The decarbonized gas is discharged from the top of the tower at a stable temperature of approximately 50°C. The tower structure utilizes a segmented bulk packing layout, with each packing layer height controlled at 1-3 meters. Gas-liquid redistributors with adjustable angles (15°-75°) are installed between layers. Dynamically adjusting the angle of the guide vanes effectively mitigates airflow disturbances caused by feed gas temperature fluctuations and ensures uniform distribution of the gas and liquid phases. Furthermore, to accommodate the corrosive conditions of the amine solution, the inner wall of the absorption tower 10 is sprayed with a polytetrafluoroethylene (PTFE) coating with excellent corrosion resistance. Its temperature resistance range extends from -30°C to 150°C, fully meeting the temperature fluctuations required during the amine regeneration process.

[0034] The distillation tower 11 decomposes the carbon dioxide-rich amine solution within the tower. The resulting high-temperature tail gas (around 100°C) is discharged from the top of the tower and directly enters the reheater 22 as a heat source to heat the low-temperature feed gas. This heat-integrated design utilizes the waste heat from the tail gas.

[0035] The heat exchange device includes an air intake pipe 20, a preheater 21, a reheater 22, a first control pipeline 23, and a second control pipeline 24. The outlet end of the air intake pipe 20 is connected to the air intake of the preheater 21 and the air intake of the reheater 22, respectively. The air intake of the preheater 21 and the air intake of the reheater 22 are respectively provided with a first solenoid valve 25. The air intake pipe 20 is provided with a second solenoid valve 26 located between the two first solenoid valves 25. It can be understood that by controlling the first solenoid valve 25 and the second solenoid valve 26, the air intake pipe 20 is provided with a second solenoid valve 26 located between the two first solenoid valves 25. Valve 26 can change whether the raw gas in the intake pipe 20 flows into the preheater 21 or the reheater 22 alone. Specifically, when the first solenoid valve 25 is opened and the second solenoid valve 26 is closed, the raw gas can be ensured to enter the preheater 21 through the first solenoid valve 25 for heating. When the first solenoid valve 25 connected to the preheater 21 is closed, the second solenoid valve 26 and another first solenoid valve 25 are opened, the raw gas can be ensured to enter the reheater 22 through the second solenoid valve 26 and the first solenoid valve 25 for heating.

[0036] Furthermore, the second solenoid valve 26 is positioned adjacent to the first solenoid valve 25. This provides a redundant safety feature and, when the raw gas flows through the preheater 21, prevents the generation of residual raw gas (residual raw gas) in the pipe section between the intake pipe 20 and the reheater 22 due to the opening and closing of the first solenoid valve 25. If the second solenoid valve 26 were farther from the first solenoid valve 25 connected to the preheater 21, the length of this pipe section would increase, significantly increasing the volume of residual gas. This "adjacent arrangement" minimizes the length of the pipe between the second solenoid valve 26 and the first solenoid valve 25 connected to the preheater 21. Closing the second solenoid valve 26 quickly isolates this area, minimizing the amount of residual gas. Reducing residual gas prevents cooling and condensation of the gas in the pipe, thus preventing the risk of liquid accumulation or corrosion within the intake pipe 20.

[0037] The first control line 23 is connected to the preheater 21, the air intake pipe 20 and the second control line 24 respectively, and the first control line 23 is configured to control the on-off and flow path of its own line. The second control line 24 is connected to the absorption tower 10 and the reheater 22, and the second control line 24 is configured to control the on-off and flow path of its own line, wherein the raw gas enters from the air intake pipe 20 and flows into the absorption tower 10 through the preheater 21 and / or the reheater 22. That is to say, the raw gas enters from the air intake pipe 20 and can enter the absorption tower 10 through the preheater 21, or the raw gas enters from the air intake pipe 20 and can enter the absorption tower 10 through the reheater 22, or the raw gas enters from the air intake pipe 20 and can enter the absorption tower 10 through the preheater 21 and then the reheater 22. The selection can be made according to the intake temperature of the raw gas.

[0038] Among them, the absorption tower 10 is connected with the preheater 21 to supply the heating medium (purified gas after decarbonization) generated by the absorption tower 10 into the preheater 21 to heat the raw gas flowing through the preheater 21, and the distillation tower 11 is connected with the reheater 22 to supply the tail gas generated by the distillation tower 11 into the reheater 22 to heat the raw gas or the preheated raw gas flowing through the reheater 22.

[0039] Specifically, an appropriate heating path can be selected according to the inlet temperature of the raw gas to achieve efficient and economical natural gas pretreatment.

[0040] Heating path one is suitable for situations where the raw gas inlet temperature is close to the inlet adaptation temperature (for example, a difference of 10°C, which can be set according to actual conditions). At this time, close the second solenoid valve 26, and by controlling the first control line 23, the raw gas flows through the first solenoid valve 25, the preheater 21, the first control line 23, the second control line 24 in sequence, and finally enters the absorption tower 10 for decarbonization. The gas after decarbonization from the absorption tower 10 is discharged from the top of the tower, and the temperature is stabilized at about 50°C. When these gases flow through the preheater 21, they will exchange heat with the low-temperature raw gas to realize the recovery of the waste heat of the absorption tower 10. Compared with the practice of directly discharging the gas after decarbonization from the absorption tower 10 in the traditional process, this design significantly improves the energy utilization efficiency.

[0041] The second heating path is suitable for scenarios where the difference between the raw gas inlet temperature and the inlet adaptation temperature is large (for example, a difference of 15°C, which can be set according to actual conditions). At this time, close the first solenoid valve 25 and the first control line 23 connected to the preheater 21, and open the second solenoid valve 26, another first solenoid valve 25 and the second control line 24 at the same time. In this way, the raw gas will flow through the second solenoid valve 26 and the first solenoid valve 25 in sequence and enter the reheater 22. At the same time, the high-temperature tail gas (about 100°C) analyzed by the distillation tower 11 is discharged from the top of the tower and directly enters the reheater 22 as a heat source to heat the low-temperature raw gas until it reaches a suitable temperature. The heated raw gas then flows into the absorption tower 10 for decarbonization.

[0042] Heating path three is designed for situations where the raw gas inlet temperature differs significantly from the inlet adaptation temperature (for example, a difference of 25 degrees Celsius, which can be set according to actual conditions). At this time, the second solenoid valve 26 is closed, and by controlling the first control line 23 and the second control line 24, the raw gas flows sequentially through the first solenoid valve 25, the preheater 21, the first control line 23, the reheater 22, the second control line 24, and finally enters the absorption tower 10. In this way, the raw gas undergoes primary heating in the preheater 21 and secondary heating in the reheater 22, reaching the appropriate temperature through two heating steps.

[0043] By coupling the heat exchange equipment with the decarbonization unit, this solution can adapt to the natural gas pretreatment needs under highly fluctuating operating conditions. By dynamically switching heating paths, the waste heat from the absorption tower 10 and the distillation tower 11 is effectively utilized. Compared to the traditional method of heating the feed gas with additional heating equipment, this solution can rationally recycle the waste heat generated by the absorption tower 10 and the distillation tower 11 as a heat source to heat the feed gas, eliminating the need for additional heating sources and significantly reducing acquisition and operating costs.

[0044] In one embodiment of the present invention, Figure 1 As shown, temperature sensors 27 are provided on the intake pipe 20, the first control line 23 and the second control line 24 for detecting the temperature of the raw gas in the intake pipe 20, the first control line 23 and the second control line 24, and the temperature sensor 27, the first solenoid valve 25 and the second solenoid valve 26, the first control line 23 and the second control line 24 are respectively connected to the external controller.

[0045] Specifically, the temperature sensor of the intake pipe 20 is used to monitor the temperature of the incoming raw gas in real time and transmit the data to an external controller. The controller compares and analyzes the measured temperature with the preset intake adaptation temperature range, thereby controlling the first solenoid valve 25 and the second solenoid valve 26, the first control pipeline 23 and the second control pipeline 24, and intelligently switching the heating path. It is suitable for natural gas pretreatment under high-fluctuation working conditions. Compared with manual switching of paths, the timing is more accurate, the control path is more precise, and the labor intensity of manual labor can be reduced. In the initial state, the first solenoid valve 25, the second solenoid valve 26, the first control pipeline 23 and the second control pipeline 24 are all closed.

[0046] Heating path 1 (temperature close to the adaptation value):

[0047] If the raw gas temperature is within the adaptation range, the controller opens the first solenoid valve 25 connected to the preheater 21, controls the path of the first control pipeline 23, and makes the raw gas flow through the preheater 21, the first control pipeline 23, and the second control pipeline 24 in sequence, and finally enters the absorption tower 10 for decarbonization.

[0048] Path 2 (large temperature deviation):

[0049] If the feed gas temperature falls below the lower limit of the adaptive range, the controller closes the first solenoid valve 25 and first control line 23 connected to the preheater 21 and opens the second solenoid valve 26, the first solenoid valve 25 connected to the reheater 22, and the second control line 24. The feed gas passes through the reheater 22 and is reheated using the high-temperature tail gas (100°C) from the distillation tower 11 as a heat source. After meeting the required temperature, it enters the absorption tower 10.

[0050] Path 3 (extreme temperature deviation):

[0051] If the feed gas temperature is significantly lower than the adaptation value, the controller closes the second solenoid valve 26, simultaneously opens the first control line 23 to connect to the intake pipe 20, and opens the second control line 24. The feed gas is first heated in the preheater 21 and then in the reheater 22. After the double heating, it enters the absorption tower 10.

[0052] In the above scheme, the temperature sensors 27 on the first control line 23 and the second control line 24 are used to monitor the raw gas temperature at the corresponding positions in real time, and transmit the data to the external controller for verifying the raw gas discharged after heating to ensure that the heated raw gas reaches the adapted temperature range and enters the absorption tower 10.

[0053] For example, in path one, the raw gas is heated by preheater 21 and flows through first control line 23. At this point, temperature sensor 27 on first control line 23 can monitor the temperature after the first stage of heating in real time, ensuring that the heat provided by preheater 21 is sufficient to raise the raw gas to the desired temperature range. If the first stage of heating fails to meet the required temperature, the controller can promptly close first control line 23 and increase the heat exchange time to ensure that the temperature meets the required standard. Once the temperature reaches the required standard, the controller will open first control line 23 in the air to deliver the raw gas to absorption tower 10.

[0054] Furthermore, the temperature sensor 27 on the intake pipe 20 is arranged near the air inlet of the intake pipe 20, the temperature sensor 27 on the first control pipeline 23 is arranged near the air outlet of the preheater 21, and the temperature sensor 27 on the second control pipeline 24 is arranged near the air outlet of the reheater 22. The intake temperature and outlet temperature of the raw gas can be obtained in time, and a timely response can be made to ensure that the raw gas can reach the adapted temperature and enter the absorption tower 10.

[0055] In one embodiment of the present invention, Figure 1 As shown, the first control pipeline 23 includes a first connecting pipe 230 and two third solenoid valves 231. The first connecting pipe 230 has an air intake pipeline and two air outlet branches. The two air outlet branches are respectively connected to the air intake pipeline, wherein the air intake pipeline is connected to the preheater 21, one air outlet branch is connected to the air intake pipe 20, and the other air outlet branch is connected to the second control pipeline 24. The two air outlet branches are respectively provided with a third solenoid valve 231.

[0056] Among them, the two third solenoid valves 231 are respectively connected to the external controller. The external controller can control the on-off of the first connecting pipe 230 by controlling the opening and closing of the two third solenoid valves 231, and can also control the connection path of the first connecting pipe 230. For example, in path one, the controller controls the third solenoid valve 231 on the outlet branch connected to the intake pipe 20 to close, and the third solenoid valve 231 on the outlet branch connected to the second control pipe 24 to open, thereby ensuring that the raw gas after the first-stage heating flows into the second control pipe 24 through the first connecting pipe 230. For another example, in path two, the two third solenoid valves 231 are controlled to be completely closed. In path three, the third solenoid valve 231 on the outlet branch connected to the intake pipe 20 is controlled to open, and the third solenoid valve 231 on the outlet branch connected to the second control pipe 24 is controlled to be closed, thereby ensuring that the raw gas after the first-stage heating flows into the reheater 22 through the first connecting pipe 230 and the intake pipe 20.

[0057] In one embodiment of the present invention, Figure 1As shown, the second control pipeline 24 includes a second connecting pipe 240 and a fourth solenoid valve 241, wherein one end of the second connecting pipe 240 is connected to the reheater 22, the other end of the second connecting pipe 240 is connected to the absorption tower 10, an outlet branch is connected to the second connecting pipe 240, and the third solenoid valve 231 and the fourth solenoid valve 241 are respectively connected to the external controller.

[0058] Specifically, in path one, the fourth solenoid valve 241 is controlled to be closed to prevent the raw gas after the first stage heating from flowing back into the reheater 22. In path two and path three, the fourth solenoid valve 241 is controlled to be open to ensure that the raw gas flowing out of the reheater 22 flows into the absorption tower 10 through the second connecting pipe 240.

[0059] In one embodiment of the present invention, Figure 1 As shown, the natural gas amine liquid decarbonization process device also includes a third connecting pipe 28, a fourth connecting pipe 29, a separator 30, a fifth solenoid valve 31 and a sixth solenoid valve 32, wherein the third connecting pipe 28 is respectively connected to the absorption tower 10, the preheater 21 and the fourth connecting pipe 29, a fifth solenoid valve 31 is provided on the branch road of the third connecting pipe 28 connected to the preheater 21, and a fifth solenoid valve 31 is provided on the branch road of the third connecting pipe 28 connected to the fourth connecting pipe 29; the fourth connecting pipe 29 is respectively connected to the preheater 21 and the separator 30, a sixth solenoid valve 32 is provided on the fourth connecting pipe 29, and the sixth solenoid valve 32 is arranged near the preheater 21, and the fifth solenoid valve 31 and the sixth solenoid valve 32 are respectively connected to the external controller.

[0060] Specifically, in the default state, the fifth solenoid valve 31 on the branch road connected to the fourth connecting pipe 29 is in a closed state, and the fifth solenoid valve 31 and the sixth solenoid valve 32 on the branch road connected to the preheater 21 are in an open state, so as to ensure that the purified gas after decarbonization of the absorption tower 10 can enter the preheater 21 through the third connecting pipe 28, heat the raw gas flowing through the preheater 21, and the purified gas after heat exchange is separated by the separator 30 and discharged.

[0061] When the preheater 21 is damaged, the fifth solenoid valve 31 and the sixth solenoid valve 32 on the branch line connected to the preheater 21 can be closed by an external controller, and the fifth solenoid valve 31 on the branch line connected to the fourth connecting pipe 29 can be opened. At this time, the purified gas after decarbonization of the absorption tower 10 can be directly transported to the separator 30 through the third connecting pipe 28 and the fourth connecting pipe 29, and then discharged from the separator 30.

[0062] In one embodiment of the present invention, Figure 1As shown, the natural gas amine liquid decarbonization process device also includes a flash tank 12, a first filter 13, and a heat exchanger 14, wherein the absorption tower 10, the flash tank 12, the first filter 13, the heat exchanger 14 and the distillation tower 11 are sequentially connected in series.

[0063] Specifically, the lean amine liquid flowing down from the top of the absorption tower 10 absorbs carbon dioxide in the absorption tower 10 to become rich amine liquid, and is discharged from the bottom of the absorption tower 10 into the flash tank 12 for flash separation after throttling and pressure reduction. The rich amine liquid after flash evaporation is filtered out of impurities through the first filter 13 and then enters the heat exchanger 14 for heating. The heated rich amine liquid enters the distillation tower 11.

[0064] In one embodiment of the present invention, Figure 1 As shown, the natural gas amine liquid decarbonization process device also includes a reboiler 15, a buffer tank 16, a first air cooler 17 and a circulation pump 18, wherein the absorption tower 10 includes a liquid phase port and a gas phase port, wherein the reboiler 15 is connected to the gas phase port for discharging the reboiled steam into the distillation tower 11, and the gas phase port, the reboiler 15, the buffer tank 16, the heat exchanger 14, the first air cooler 17, the circulation pump 18 and the absorption tower 10 are connected in series in sequence.

[0065] Specifically, the heated rich amine liquid enters the distillation tower 11 and is countercurrently contacted with the reboiled flash steam in the reboiler 15 and discharged into the absorption tower 10 through the gas phase port to decompose the carbon dioxide, which is discharged from the distillation tower 11 to the reheater 22. The rich amine liquid enters the reboiler 15 from the bottom of the distillation tower 11 to be reboiled, heated, regenerated and purified into lean amine liquid. The lean amine liquid enters the buffer tank 16 for temporary buffering and is then discharged into the heat exchanger 14. After heat exchange and cooling with the rich amine liquid filtered by the first filter 13, it enters the first air cooler 17. After cooling again, it enters the circulation pump 18 for pressurization and is then discharged into the absorption tower 10 for recycling.

[0066] In one embodiment of the present invention, Figure 1 As shown, the natural gas amine liquid decarbonization process device further includes a fifth connecting pipeline 33 , a sixth connecting pipeline 34 , a seventh solenoid valve 35 , and an eighth solenoid valve 36 .

[0067] Among them, the fifth connecting line 33 is connected to the reheater 22 and the sixth connecting line 34 respectively, and a seventh solenoid valve 35 is provided on the branch line connecting the fifth connecting line 33 and the reheater 22, and a seventh solenoid valve 35 is provided on the branch line connecting the fifth connecting line 33 and the sixth connecting line. One end of the sixth connecting line 34 is connected to the reheater 22, and the other end of the sixth connecting line 34 is connected to the distillation tower 11, and an eighth solenoid valve 36 is provided on the sixth connecting line 34. The eighth solenoid valve 36 is arranged near the reheater 22, and the seventh solenoid valve 35 and the eighth solenoid valve 36 are respectively connected to the external controller.

[0068] In the above scheme, in the default state, the seventh solenoid valve 35 and the eighth solenoid valve 36 on the branch road connected to the reheater 22 are in the open state, and the seventh solenoid valve 35 on the branch road connected to the sixth connecting pipe is in the closed state, so as to ensure that the high-temperature exhaust gas rich in carbon dioxide discharged from the top of the distillation tower 11 can flow into the reheater 22 through the fifth connecting pipe 33, heat the raw gas flowing through the reheater 22, and the exhaust gas after heat exchange flows out through the sixth connecting pipe 34.

[0069] When the reheater 22 is overhauled or damaged, in order to avoid excessive pressure inside the distillation tower 11, the seventh solenoid valve 35 and the eighth solenoid valve 36 on the branch line connected to the reheater 22 can be controlled to a closed state, and the seventh solenoid valve 35 on the branch line connected to the sixth connecting pipe 34 can be controlled to an open state, thereby ensuring that the exhaust gas can be discharged normally.

[0070] Furthermore, if Figure 1 As shown, the natural gas amine liquid decarbonization process device also includes a second air cooler 37, a reflux tank 38 and a reflux pump 39, wherein the sixth connecting pipeline 34 is used to connect the second air cooler 37, the reflux tank 38, the reflux pump 39 and the distillation tower 11 in series in sequence.

[0071] Specifically, the tail gas after heat exchange and cooling enters the second air cooler 37 for further cooling, and then flows back to the reflux tank 38 for further analysis and separation. The separated liquid phase is pumped into the distillation tower 11 through the reflux pump 39 for liquid replenishment, and the separated gas phase is discharged from the reflux tank 38 and enters the downstream device for recycling.

[0072] In one embodiment of the present invention, Figure 1 As shown, a second filter 19 is provided on the second connecting pipe 240 .

[0073] In the above solution, the second filter 19 is provided to filter impurities from the raw gas flowing through the second connecting pipe 240 , thereby reducing the amount of dirt entering the absorption tower 10 , reducing the cleaning frequency, and improving the decarbonization efficiency.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0075] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments described herein, but is to be construed in the widest manner consistent with the principles and novel features disclosed herein.

Claims

1. A natural gas amine liquid decarbonization process device, characterized in that: include: Decarbonization equipment, including an absorption tower and a distillation tower, wherein the absorption tower and the distillation tower are connected; A heat exchange device, comprising an air intake pipe, a preheater, a reheater, a first control pipeline, and a second control pipeline, wherein the outlet end of the air intake pipe is respectively connected to the air intake of the preheater and the air intake of the reheater, and the air intake of the preheater and the air intake of the reheater are respectively provided with a first solenoid valve, and the air intake pipe is provided with a second solenoid valve located between the two first solenoid valves; The first control pipeline is respectively connected to the preheater, the air inlet pipe and the second control pipeline, and the first control pipeline is configured to control the on / off and flow path of the pipeline itself. The second control pipeline is connected to the absorption tower and the reheater, and the second control pipeline is configured to control the on / off and flow path of the pipeline itself. The raw gas enters from the air inlet pipe, flows into the absorption tower through the preheater and / or the reheater; The absorption tower is connected to the preheater so that the heating medium generated by the absorption tower is supplied to the preheater to heat the raw gas flowing through the preheater, and the distillation tower is connected to the reheater so that the tail gas generated by the distillation tower is supplied to the reheater to heat the raw gas or preheated raw gas flowing through the reheater.

2. The natural gas amine liquid decarbonization process device according to claim 1, characterized in that: The intake pipe, the first control pipeline and the second control pipeline are each provided with a temperature sensor for detecting the temperature of the raw gas in the intake pipe, the first control pipeline and the second control pipeline, and the temperature sensor, the first solenoid valve and the second solenoid valve, the first control pipeline and the second control pipeline are respectively connected to an external controller.

3. The natural gas amine liquid decarbonization process device according to claim 2, characterized in that: The first control pipeline includes a first connecting pipe and two third solenoid valves, the first connecting pipe has an air intake pipeline and two air outlet branches, the two air outlet branches are respectively connected to the air intake pipeline, wherein the air intake pipeline is connected to the preheater, one air outlet branch is connected to the air intake pipe, and the other air outlet branch is connected to the second control pipeline, and the third solenoid valves are respectively provided on the two air outlet branches.

4. The natural gas amine liquid decarbonization process device according to claim 3, characterized in that: The second control pipeline includes a second connecting pipe and a fourth solenoid valve, wherein one end of the second connecting pipe is connected to the reheater, the other end of the second connecting pipe is connected to the absorption tower, one of the gas outlet branches is connected to the second connecting pipe, and the third solenoid valve and the fourth solenoid valve are respectively connected to an external controller.

5. The natural gas amine liquid decarbonization process device according to claim 1, characterized in that: It also includes a third connecting pipe, a fourth connecting pipe, a separator, a fifth solenoid valve and a sixth solenoid valve, wherein: The third connecting pipe is respectively connected to the absorption tower, the preheater and the fourth connecting pipe. The branch line of the third connecting pipe connected to the preheater is provided with the fifth solenoid valve. The branch line of the third connecting pipe connected to the fourth connecting pipe is provided with the fifth solenoid valve. The fourth communicating pipe is connected to the preheater and the separator respectively. The sixth solenoid valve is provided on the fourth communicating pipe and is arranged adjacent to the preheater. The fifth solenoid valve and the sixth solenoid valve are connected to an external controller respectively.

6. The natural gas amine liquid decarbonization process device according to claim 1, characterized in that: It also includes a flash tank, a first filter, and a heat exchanger, wherein the absorption tower, the flash tank, the first filter, the heat exchanger and the distillation tower are sequentially connected in series.

7. The natural gas amine liquid decarbonization process device according to claim 6, characterized in that: It also includes a reboiler, a buffer tank, a first air cooler and a circulation pump, wherein the absorption tower includes a liquid phase port and a gas phase port, wherein the reboiler is connected to the gas phase port for discharging reboiled steam into the distillation tower, and the gas phase port, the reboiler, the buffer tank, the heat exchanger, the first air cooler, the circulation pump and the absorption tower are connected in series in sequence.

8. The natural gas amine liquid decarbonization process device according to claim 1, characterized in that: It also includes a fifth connecting pipeline, a sixth connecting pipeline, a seventh solenoid valve, and an eighth solenoid valve, wherein: The fifth communicating line is connected to the reheater and the sixth communicating line respectively, the seventh solenoid valve is provided on the branch line between the fifth communicating line and the reheater, and the seventh solenoid valve is provided on the branch line between the fifth communicating line and the sixth communicating line; One end of the sixth communicating pipe is connected to the reheater, and the other end of the sixth communicating pipe is connected to the distillation tower, and the eighth solenoid valve is provided on the sixth communicating pipe, and the eighth solenoid valve is arranged adjacent to the reheater, and the seventh solenoid valve and the eighth solenoid valve are respectively connected to an external controller.

9. The natural gas amine liquid decarbonization process device according to claim 8, characterized in that: It also includes a second air cooler, a reflux tank and a reflux pump, wherein the sixth connecting pipeline is used to connect the second air cooler, the reflux tank, the reflux pump and the distillation tower in series in sequence.

10. The natural gas amine liquid decarbonization process device according to claim 4, characterized in that: The second connecting pipe is provided with a second filter.

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