Gas-heat self-circulation ethylene glycol regeneration and tail gas treatment system

Abstract

The application discloses a gas-heat self-circulation ethylene glycol regenerating and tail gas processing system, belongs to the field of ethylene glycol regenerating and tail gas processing in natural gas gathering and injection and storage, and aims to solve the technical problems of low energy utilization rate and low energy-saving property in the prior art. The tail gas generated by the ethylene glycol regenerating device is pressurized and heated, and then is used as a heat source to heat the ethylene glycol dilute solution, so that a double self-circulation of the tail gas and heat energy is formed, and the heat energy in the tail gas is fully recycled and utilized. The tail gas is burned in a tail gas burning furnace to generate high-temperature flue gas, and the high-temperature flue gas is used to heat the pressurized and heated recirculated tail gas, so that the tail gas temperature is higher and the heating effect is better, and the waste heat in the flue gas can be fully utilized to avoid heat energy waste. Since the system forms a heat energy self-circulation process and a burning furnace heat supplement process, the front-end ethylene glycol regenerating tower does not need additional fuel to provide heat energy, the overall energy-saving property is better, and the system efficiency is higher.

Description

TECHNICAL FIELD

[0001] The present inventors belong to the field of natural gas injection and storage, and relate to a glycol regeneration and tail gas treatment, in particular to a gas-heat self-circulation glycol regeneration and tail gas treatment system. BACKGROUND

[0002] Natural gas storage needs to be periodically injected and produced, and there is a process of reducing the pressure of natural gas during the production process. If the water content in the natural gas is large at this time, ice blocking problem is easy to occur, and the presence of condensed water will accelerate the corrosion of subsequent pipelines and equipment; therefore, the natural gas needs to be dehydrated.

[0003] The oxalate method used in the prior art to prepare ethylene glycol is generally based on coal as raw material, which is gasified, shifted, purified and separated and purified to obtain CO and H2, wherein CO is combined by catalytic coupling and refined to produce dimethyl carbonate (DMC), and then hydrogenated with H2 and refined to obtain polyester-grade ethylene glycol. However, the process of coal-to-ethylene glycol also involves tail gas treatment, which has similarities with the ethylene glycol tail gas treatment involved in the application.

[0004] The invention patent application with application number 201910198857.1 discloses an ethylene glycol esterification tail gas treatment device and method. The ethylene glycol esterification tail gas treatment device includes a incinerator, a first waste heat recovery device, a N2O removal unit, a NOx removal unit, a second waste heat recovery device and a fan. The ethylene glycol esterification tail gas treatment method includes the following steps: (1) incineration, (2) first waste heat recovery, (3) N2O removal, (4) NOx removal, (5) second waste heat recovery, (6) discharge. The advantages of the present invention are that by controlling the flow of fuel gas and air, the temperature in the incinerator is controlled at 1100℃-1200℃, not only can the methyl nitrite in the esterification tail gas be decomposed, and CO can be converted to CO2, but also the increase of N2 caused by the decomposition of N2O can be avoided, thereby reducing the N0x generated by the reaction of N2 and O2, and reducing the investment cost of subsequent N0x removal; the N2O removal unit can effectively remove N2O in the flue gas, reduce the N2O content in the flue gas, ensure that the total content of N2O and N0x in the exhaust flue gas meets the standard, so that the exhaust flue gas is environmentally friendly and safe.

[0005] The utility model discloses a kind of ethylene glycol tail gas treatment systems with application number 202220859362.6, which includes tail gas absorption tower and secondary absorption tower, the upper portion of the tail gas absorption tower is connected with methanol delivery pump by pipeline, and the lower portion is connected with synthetic circulating gas pipeline and air buffer tank by pipeline;The secondary absorption tower is double-section structure, the upper section of secondary absorption tower is reaction absorption tower, and the lower section is methanol absorption tower, the gas outlet at the top of tail gas absorption tower is connected with the gas inlet at the lower portion of methanol absorption tower by pipeline, the liquid inlet for spraying at the upper portion of reaction absorption tower and methanol absorption tower is connected with desalted water pressurizing pump by pipeline, the gas outlet at the top of methanol absorption tower is connected with the gas inlet at the lower portion of reaction absorption tower by pipeline, the air inlet at the lower portion of reaction absorption tower is connected with air buffer tank by pipeline, and the gas outlet at the top of reaction absorption tower is connected with tail gas absorption lye tank by pipeline.The utility model can effectively remove nitrogen oxides in synthetic circulating gas, and by-product nitric acid is produced, and the remaining tail gas is sent to a boiler for incineration, reducing resource waste.

[0006] In the prior art, in the low-temperature separation dehydration and solvent absorption dehydration processes, a large amount of heat energy is consumed to heat the low-temperature ethylene glycol rich solution to above 100 DEG C, so that the water therein is evaporated to concentrate the ethylene glycol, and finally produce a poor solution with a high temperature; meanwhile, a large amount of high-temperature tail gas is produced, the tail gas contains a large amount of superheated water vapor, carries away a large amount of residual heat, forms resource waste; meanwhile, the tail gas contains a small amount of ethylene glycol and insoluble hydrocarbon gas, the existence of high temperature and organic matter does not allow the tail gas to be directly discharged, and the tail gas needs to be incinerated, but due to the fact that the tail gas contains a large amount of water vapor, the tail gas flow is too large, and thus the incineration of the tail gas consumes a large amount of energy; in addition, the condensate water produced after the tail gas is treated has a high temperature, which is not conducive to discharge. At the same time, the flue gas produced by heating and incinerating the ethylene glycol also contains a large amount of residual heat, and the residual heat is not utilized, forming resource waste. SUMMARY

[0007] The present application aims at solving the technical problems of low energy utilization rate and low energy saving in high-temperature tail gas in the prior art, and provides a gas-heat self-circulation ethylene glycol regeneration and tail gas treatment system.

[0008] In order to achieve the above-mentioned purpose, the present application specifically adopts the following technical scheme:

[0009] The system comprises a reboiler, a first flash tank and a burning furnace, the reboiler is sequentially provided with an ethylene glycol regeneration tower and a rectifying column, the inlet of the rectifying column is communicated with the rich liquid inlet, the outlet of the rectifying column is communicated with the first flash tank through a rich liquid flash connection pipe, and the liquid outlet of the first flash tank is communicated with the ethylene glycol regeneration tower through a rich liquid regeneration connection pipe; the outlet at the top of the rectifying column is communicated with a gas-liquid separator through a tail gas pipe, the tail gas outlet at the top of the gas-liquid separator is communicated with a steam compressor through a compression suction pipe, the outlet of the steam compressor is communicated with a flue gas heat exchanger through a compression exhaust pipe, the tail gas outlet of the flue gas heat exchanger is communicated with the heating pipe inlet of the reboiler through a high-temperature tail gas pipe; the heating pipe outlet of the reboiler is communicated with a second flash tank through a condensed water outlet pipe, the gas outlet of the second flash tank is communicated with a gas-liquid separation cooler through a flash tail gas pipe, the liquid outlet of the second flash tank is communicated with the liquid pipe of the gas-liquid separation cooler through a flash water pipe, the gas outlet of the gas-liquid separation cooler is communicated with the tail gas inlet of the burning furnace through a non-condensable gas pipe, the flue gas outlet of the burning furnace is communicated with the flue gas inlet of the flue gas heat exchanger through a flue gas pipe, the flue gas outlet of the flue gas heat exchanger is communicated with a smoke exhaust, the liquid outlet of the gas-liquid separation cooler is communicated with a water outlet, and the liquid outlet of the gas-liquid separator is communicated with the inlet of the second flash tank through a liquid distribution pipe and a condensed water flash connection pipe.

[0010] Further, a throttling pressure reducing valve is arranged on the condensed water outlet pipe.

[0011] Further, the condensed water and the insoluble gas discharged through the condensed water outlet pipe are reduced in pressure through the throttling pressure reducing valve, then are discharged into the second flash tank through the condensed water flash connection pipe, are combined with the liquid water discharged through the liquid distribution pipe and are subjected to a flash process in the second flash tank, part of the condensed water is changed into water vapor and the non-condensable gas is discharged into the upper part of the gas-liquid separation cooler through the flash tail gas pipe, the remaining condensed water is reduced in temperature and is discharged into the lower part of the gas-liquid separation cooler through the flash water pipe; finally, the gas part and the liquid part are fully cooled in the gas-liquid separation cooler, the water vapor in the tail gas is condensed into liquid water and is combined with the lower condensed water, is finally discharged out of the system through the water outlet, the remaining tail gas is discharged into the burning furnace through the non-condensable gas pipe, the flue gas is formed after the fuel in the burning furnace is burned, and participates in the heat exchange process in the flue gas heat exchanger.

[0012] Further, a guide valve is arranged on the compression exhaust pipe, and a shut-off valve is arranged on the water supply opening.

[0013] Further, when the system is initially started, fuel is introduced through the fuel inlet, the burning furnace is turned on to make the burning furnace generate a large amount of high-temperature flue gas; at the same time, the shutoff valve is turned on, and liquid water is supplemented from the water supplement inlet. Due to the presence of the one-way valve, the liquid water can only enter the flue gas heat exchanger and be heated by the high-temperature flue gas to form water vapor; the water supplement pressure is set to make the water vapor generated in the flue gas heat exchanger have a higher temperature. Thereafter, the heavy boiler is connected to the high-temperature tail gas pipe to heat the ethylene glycol solution. After the heated ethylene glycol solution generates tail gas and enters the compressed suction pipe, the steam compressor is turned on, and the shutoff valve is closed. Thereafter, the steam circulation heating process is operated.

[0014] The beneficial effects of the present application are as follows:

[0015] 1. In the present application, the tail gas generated by the ethylene glycol regeneration device is pressurized and heated to serve as a heat source to heat the ethylene glycol dilute solution, forming a double self-circulation of tail gas and heat energy, and the heat energy in the tail gas is fully recovered and utilized. At the same time, the tail gas burning furnace burns the tail gas to generate high-temperature flue gas, which is used to heat the pressurized and heated recycled tail gas. On the one hand, the tail gas has a higher temperature and better heating effect, and on the other hand, the waste heat in the flue gas is fully utilized to avoid waste of heat energy. At the same time, since the system forms a heat energy self-circulation process and a burning furnace heat supplement process, the front-end ethylene glycol regeneration tower no longer needs additional fuel to provide heat energy, the overall energy saving is better, and the system efficiency is higher.

[0016] 2. In the present application, the high-temperature tail gas generated in the ethylene glycol regeneration process is fully utilized to extract heat energy and utilize it, and the tail gas itself is pressurized and heated to heat the ethylene glycol dilute solution, forming a self-circulation process combined with gas and heat, without the need to additionally increase the heat energy carrier. At the same time, the heat energy in the tail gas is fully recovered and utilized, the proportion of heat energy recovery and utilization is large, the efficiency is high, and the waste of heat energy in the tail gas is avoided. At the same time, the tail gas burning furnace burns the tail gas to generate high-temperature flue gas, which is used to heat the pressurized and heated recycled tail gas. On the one hand, the heating effect of the self-circulating tail gas is improved, and on the other hand, the waste heat in the flue gas is fully utilized. Further, since the system forms a heat energy self-circulation process and a burning furnace heat supplement process, the front-end ethylene glycol regeneration tower no longer needs additional fuel to provide heat energy, the overall energy saving is better, and the system efficiency is higher (the energy efficiency value reaches 34.3, which is 38 times that of the fuel direct combustion heating method).

[0017] 3. In the present application, the system originally uses the tail gas to heat, pressurize and recycle, heats and concentrates the system's own ethylene glycol rich solution, forms regenerated ethylene glycol lean solution, and synchronously generates tail gas that can be recycled and utilized, without the need to additionally set a continuous heat source for heating.

[0018] 4. In this invention, the system recovers and utilizes the heat from the high-temperature flue gas generated by the furnace, and raises the temperature of the heated and pressurized exhaust gas, thereby reducing the waste of flue gas heat and improving energy utilization.

[0019] 5. In this invention, the self-circulating tail gas in the system heats the ethylene glycol-rich liquid and condenses it into high-pressure liquid water. The phase change releases a huge amount of latent heat, resulting in high heating efficiency. In addition, the waste heat from the combustion furnace flue gas is recovered and utilized, making the overall system energy-efficient.

[0020] 6. In this invention, after the system's self-circulating tail gas is condensed, it enters the flash tank through throttling and pressure reduction, generating some tail gas and residual condensate. After being fully cooled by the gas-liquid stratification cooler, the amount of residual tail gas is extremely small, reducing the fuel required for the combustion furnace, which is more conducive to saving resources, reducing energy consumption and carbon emissions. Moreover, the condensate temperature after being cooled again by the gas-liquid stratification cooler is low, meeting emission standards. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the present invention;

[0022] The attached figures are labeled as follows:

[0023] 1-Lean liquor outlet, 2-Reboiler, 3-Ethylene glycol regeneration tower, 4-First flash tank, 5-Flash vapor outlet, 6-Rich liquor inlet, 7-Distillation column, 8-Gas-liquid separator, 9-Steam compressor, 10-Check valve, 11-Make-up water inlet, 12-Shut-off valve, 13-Flue gas heat exchanger, 14-Flue exhaust outlet, 15-Oxidizer, 16-Gas fuel inlet, 17-Drain outlet, 18-Gas-liquid stratification cooler 19-Second flash tank, 20-Throttle and pressure reducing valve, 01-Rich liquid flash evaporation connection, 02-Rich liquid regeneration connection, 03-Tail gas pipe, 04-Divider pipe, 05-Compressed suction pipe, 06-Compressed exhaust pipe, 07-High temperature tail gas pipe, 08-Flash evaporation tail gas pipe, 09-Flue gas pipe, 010-Non-condensable gas pipe, 011-Flash water pipe, 012-Condensate flash evaporation connection, 013-Condensate outlet pipe. Detailed Implementation

[0024] A gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system, the structure of which is as follows: Figure 1 As shown, the system is equipped with a reboiler 2, on which an ethylene glycol regeneration tower 3 and a distillation column 7 are mounted. The rich liquid inlet 6 is connected to the inlet of the distillation column 7, and the outlet of the distillation column 7 is connected to the inlet of the first flash tank 4 via a rich liquid flash evaporation connector 01. The liquid outlet of the first flash tank 4 is connected to the ethylene glycol regeneration tower 3 via a rich liquid regeneration connector 02. The gas inlet 16 is located on the combustion furnace 15, and the flue gas outlet at the top of the combustion furnace 15 is connected to the flue gas inlet of the flue gas heat exchanger 13 via a flue gas pipe 09. The flue gas outlet of the flue gas heat exchanger 13 is connected to the exhaust port 14.

[0025] As Figure 1 shown, the top outlet of rectification column 7 is connected with gas-liquid separator 8 through tail gas pipe 03, the tail gas outlet at the top of gas-liquid separator 8 is connected with the inlet of vapor compressor 9 through compression suction pipe 05, the outlet of vapor compressor 9 is connected with the tail gas inlet of flue gas heat exchanger 13 through compression exhaust pipe 06, the tail gas outlet of flue gas heat exchanger 13 is connected with the heating pipe inlet of reboiler 2 through high-temperature tail gas pipe 07. The heating pipe outlet of reboiler 2 is connected with the inlet of second flash tank 19 through condensed water outlet pipe 013; the gas outlet of second flash tank 19 is connected with the gas pipe inlet of gas-liquid separation cooler 18 through flash tail gas pipe 08, while the liquid outlet of second flash tank 19 is connected with the liquid pipe inlet of gas-liquid separation cooler 18 through flash water pipe 011. The gas outlet of gas-liquid separation cooler 18 is connected with the tail gas inlet of combustion furnace 15 through 010 non-condensable gas pipe, and the liquid outlet of gas-liquid separation cooler 18 is connected with drain 17. In addition, the liquid outlet of gas-liquid separator 8 is connected with condensed water flash connection pipe 012 through liquid separation pipe 04, and then connected with the inlet of second flash tank 19; water supply port 11 is connected with compression exhaust pipe 06. Among them, a one-way valve 10 is arranged on compression exhaust pipe 06 between vapor compressor 9 and water supply port 11, a shutoff valve 12 is arranged on water supply port 11, and a throttling pressure reducing valve 20 is arranged on condensed water outlet pipe 013.

[0026] As Figure 1 shown, when the system is running, the ethylene glycol rich liquid generated by the front-end equipment of the system enters rectification column 7 through rich liquid inlet 6, is preheated, and then enters first flash tank 4 through rich liquid flash connection pipe 01 to perform a flash process, in which part of the water is flashed to form water vapor and is discharged through 5 flash vapor outlet; the remaining ethylene glycol rich liquid enters ethylene glycol regeneration tower 3 and reboiler 2 through rich liquid regeneration connection pipe 02, and after being heated multiple times, the water in it is fully evaporated to form ethylene glycol lean liquid, which is discharged through lean liquid outlet 1 for circulation in the front-end production.

[0027] As Figure 1As shown, when the system is running, the ethylene glycol rich solution is heated and concentrated in the reboiler 2 and the ethylene glycol regeneration tower 3 to form an ethylene glycol lean solution, and the water therein is heated to form water vapor which is discharged from the top of the rectification column 7 into the tail gas pipe 03, then enters the gas-liquid separator 8, and forms separation in the gas-liquid separator 8, and the separated liquid water is discharged from the gas-liquid separator 8 into the second flash tank 19 through the liquid separation pipe 04, and the remaining water vapor and other non-condensable gases are sucked into the steam compressor 9 through the compressed suction pipe 05 in the form of tail gas; the tail gas is compressed and heated by the steam compressor 9, and then discharged into the flue gas heat exchanger 13 through the compressed exhaust pipe 06. At the same time, the fuel such as natural gas is burned in the combustion furnace 15 through the fuel inlet 16 to form high-temperature flue gas, and is introduced into the other side of the flue gas heat exchanger 13 through the flue gas pipe 09. In this way, the tail gas compressed and heated by the steam compressor 9 is heated again by the high-temperature flue gas in the flue gas heat exchanger 13, and the temperature is further increased. Thereafter, the high-temperature and high-pressure tail gas is introduced into the heating pipe of the reboiler 2 through the high-temperature tail gas pipe 07 to heat the ethylene glycol rich solution. Because the temperature of the ethylene glycol rich solution is low, and the temperature and pressure of the tail gas are high, the water vapor in the high-temperature and high-pressure tail gas is condensed into liquid during the heating process of the ethylene glycol solution, and finally discharged from the reboiler 2 through the condensed water outlet pipe 013. In this way, the water vapor in the tail gas generated from the heated side of the reboiler 2 is separated by water, compressed, heated by flue gas, and then introduced into the heating side of the reboiler 2 to heat the ethylene glycol solution on the heated side, and the whole process completes a self-circulation.

[0028] As shown in Figure 1 the condensed water and insoluble gas discharged from the condensed water outlet pipe 013 pass through the throttling pressure reducing valve 20, the pressure is reduced, and then discharged into the second flash tank 19 through the condensed water flash connection pipe 012, and combined with the liquid water discharged through the liquid separation pipe 04 and undergoes a flash process in the second flash tank 19, part of the condensed water is changed into water vapor and non-condensable gas, and discharged into the upper part of the gas-liquid separation cooler 18 through the flash tail gas pipe 08, and the remaining condensed water is cooled and discharged into the lower part of the gas-liquid separation cooler 18 through the flash water pipe 011; finally, the gas part and the liquid part are fully cooled in the gas-liquid separation cooler 18, the water vapor in the tail gas is condensed into liquid water and combined with the lower condensed water, and finally discharged from the system through the water outlet 17, and the remaining tail gas is discharged into the combustion furnace 15 through the non-condensable gas pipe 010, and the flue gas is formed after the fuel burned therein is burned, and participates in the heat exchange process in the flue gas heat exchanger 13.

[0029] As shown in Figure 1As shown, when the system is initially started, the vapor compressor 9 cannot work because no water vapor circulation process is formed in the system; at this time, fuel is needed to be introduced through the fuel inlet 16, and the burner 15 is opened to generate a large amount of high-temperature flue gas. At the same time, the shut-off valve 12 is opened, and liquid water is supplemented from the water supplement inlet 11. Due to the presence of the one-way valve 10, the liquid water can only enter the flue gas heat exchanger 13 and be heated by the high-temperature flue gas to form water vapor; the water supplement pressure is set to make the water vapor generated in the flue gas heat exchanger 13 have a high temperature, and then the high-temperature tail gas pipe 07 is used to introduce the reboiler 2 to heat the ethylene glycol solution. After the heated ethylene glycol solution generates tail gas and enters the compression suction pipe 05, the vapor compressor 9 is opened, and the shut-off valve 12 is closed; thereafter, the vapor circulation heating process is run.

[0030] Example 1

[0031] The original ethylene glycol rich solution is heated to generate tail gas at 105°C, which enters the compressor 9 through the tail gas pipe 03, the gas-liquid separator 8, and the compressor suction pipe 05, and is compressed to 0.3 MPa (corresponding to a saturated temperature of 133.5°C). Then, it is discharged into the flue gas heat exchanger 13. At the same time, the burner 15 generates high-temperature flue gas above 500°C, which is discharged into the flue gas heat exchanger 13 to exchange heat with the tail gas, so that the tail gas is heated to 140°C, and the flue gas temperature is reduced to 150°C. The tail gas at 140°C / 0.3 MPa enters the heating side of the reboiler 2 through the high-temperature tail gas pipe 07 to heat the ethylene glycol solution on the heated side, so that the liquid water in the ethylene glycol solution on the heated side evaporates to form tail gas at 105°C, and the high-temperature tail gas on the heating side is cooled and condensed to form liquid water at 110°C / 0.3 MPa. The above liquid water is reduced in pressure to 0.1 MPa through the throttling pressure reducing valve 20, so as to enter the second flash tank 19 to undergo a flash process to form part of water vapor at 100°C and the remaining liquid water.

[0032] In the above specific implementation process, if 1 m3 (1000 kg) of liquid water in the ethylene glycol rich solution needs to be heated and evaporated, and is discharged into the subsequent circulating system in the form of tail gas (water vapor accounts for 95%), then during the entire self-circulation heating process, 105℃ / 0.12MPa water vapor 1418m3 (enthalpy 2683kJ / kg) is generated, the volume becomes 606m3 (enthalpy 2725kJ / kg) after being compressed by the steam compressor 9 to 0.3MPa tail gas, the compressor does work 42MJ; then heated to 140℃ by the flue gas heat exchanger 13 (enthalpy 2739kJ / kg) to absorb heat 14MJ, the volume is 617m3. Thereafter, it enters the reboiler 2 to heat the ethylene glycol solution, forming 110℃ / 0.3MPa condensed water (unsaturated water, enthalpy 461kJ / kg), which can release heat 2278MJ, and can make 1.016m3 (1016kg) of liquid water in the ethylene glycol solution be evaporated into 105℃ / 0.12MPa water vapor, and then enter the self-circulation heating process again. Since the total amount of water vapor generated again is 1016kg, which is greater than the 1000kg initially entered into the circulation, the self-heating cycle can continue.

[0033] In the above entire process, the steam compressor 9 consumes 50MJ of electric energy (considering the mechanical efficiency of 84%), the burner 15 consumes 0.49Nm3 of fuel natural gas (considering the comprehensive thermal efficiency of the burner 15 and the flue gas heat exchanger 13 is 85%, the heat value of natural gas is 33.4MJ / Nm3, and the energy consumption is 16.5MJ), and the self-circulation heating system has a comprehensive efficiency of 34.3 (2278 / 66.5). If the original natural gas is used as fuel to heat and concentrate the ethylene glycol rich solution, then the above 1m3 of liquid water needs 74.6Nm3 of natural gas to be evaporated (the heat demand is 2243MJ, the heat value of natural gas is 33.4MJ / Nm3, and the combustion and heat exchange efficiency is taken as the higher value 90%), the heat consumption is 2492MJ, and the system efficiency is 38 times the original efficiency.

Claims

1. A gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system, characterized in that: The system includes a reboiler (2), a first flash tank (4), and a furnace (15). The reboiler (2) is sequentially equipped with an ethylene glycol regeneration tower (3) and a distillation column (7). The inlet of the distillation column (7) is connected to the rich liquid inlet (6), and the outlet of the distillation column (7) is connected to the first flash tank (4) via a rich liquid flash evaporation connector (01). The liquid outlet of the first flash tank (4) is connected to the ethylene glycol regeneration tower (3) via a rich liquid regeneration connector (02). The top of the distillation column (7)... The outlet is connected to a gas-liquid separator (8) via a tail gas pipe (03). The tail gas outlet at the top of the gas-liquid separator (8) is connected to a steam compressor (9) via a compression suction pipe (05). The outlet of the steam compressor (9) is connected to a flue gas heat exchanger (13) via a compression exhaust pipe (06). The tail gas outlet of the flue gas heat exchanger (13) is connected to the heating tube inlet of the reboiler (2) via a high-temperature tail gas pipe (07). The heating tube outlet of the reboiler (2) is connected to the condensate outlet. Pipe (013) connects to a second flash tank (19). The gas outlet of the second flash tank (19) is connected to a gas-liquid stratification cooler (18) via a flash tail gas pipe (08). The liquid outlet of the second flash tank (19) is connected to the liquid pipe of the gas-liquid stratification cooler (18) via a flash water pipe (011). The gas outlet of the gas-liquid stratification cooler (18) is connected to the tail gas inlet of the calciner (15) via a non-condensable gas pipe (010). The flue gas from the calciner (15) exits... The outlet is connected to the flue gas inlet of the flue gas heat exchanger (13) through the flue gas pipe (09). The flue gas outlet of the flue gas heat exchanger (13) is connected to the exhaust port (14). The liquid outlet of the gas-liquid stratified cooler (18) is connected to the drain port (17). The liquid outlet of the gas-liquid separator (8) is connected to the condensate flash evaporation pipe (012) through the liquid distribution pipe (04) and then connected to the inlet of the second flash tank (19). The middle part of the compressed exhaust pipe (06) is connected to the water inlet (11).

2. The gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system as described in claim 1, characterized in that: A throttling and pressure reducing valve (20) is installed on the condensate outlet pipe (013).

3. The gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system as described in claim 2, characterized in that: The condensate and insoluble gases discharged through the condensate outlet pipe (013) are depressurized after passing through the throttling and pressure reducing valve (20), and then discharged into the second flash tank (19) through the condensate flash evaporation pipe (012). There, they merge with the liquid water discharged through the separator pipe (04) and undergo a flash evaporation process in the second flash tank (19). Part of the condensate then turns into water vapor and, along with the insoluble gases, is discharged into the upper part of the gas-liquid stratification cooler (18) through the flash evaporation tail gas pipe (08). The remaining condensate temperature... The temperature is reduced and discharged into the lower part of the gas-liquid stratified cooler (18) through the flash water pipe (011); finally, both the gas and liquid parts are fully cooled in the gas-liquid stratified cooler (18), and the water vapor in the tail gas is condensed into liquid water and merged with the lower layer of condensate. Finally, it is discharged from the system through the drain outlet (17), and the remaining tail gas is discharged into the combustion furnace (15) through the non-condensable gas pipe (010). After being burned by the fuel in it, it forms flue gas and participates in the heat exchange process in the flue gas heat exchanger (13).

4. The gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system as described in claim 1, characterized in that: A one-way valve (10) is installed on the compressed exhaust pipe (06), and a shut-off valve (12) is installed on the water inlet (11).

5. The gas-heat self-circulating ethylene glycol regeneration and tail gas treatment system as described in claim 4, characterized in that: When the system is initially started, fuel is introduced through the gas inlet (16), and the combustion furnace (15) is turned on to generate a large amount of high-temperature flue gas. At the same time, the shut-off valve (12) is turned on and liquid water is added from the water inlet (11). Due to the presence of the check valve (10), the liquid water can only enter the flue gas heat exchanger (13) and is heated by the high-temperature flue gas to form water vapor. The water supply pressure is set so that the water vapor generated in the flue gas heat exchanger (13) has a high temperature. Afterwards, it is introduced into the reboiler (2) through the high-temperature tail gas pipe (07) to heat the ethylene glycol solution. After the heated ethylene glycol solution generates tail gas and enters the compressed air intake pipe (05), the steam compressor (9) is turned on and the shut-off valve (12) is turned off. Then the steam circulation heating process is run.

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