An amine rich liquid hydrogen sulfide concentration device

Abstract

The utility model discloses an amine rich liquid hydrogen sulfide concentration device belongs to desulfurization equipment technical field, it includes absorption tower, rich and poor liquid heat exchanger, carbon dioxide high pressure regenerator, gas -liquid heat exchanger, hydrogen sulfide normal pressure regenerator, liquid heater and poor liquid cooler, and the rich liquid of the absorption of hydrogen sulfide and carbon dioxide of the rich liquid discharge port of absorption tower is discharged and flows into carbon dioxide high pressure regenerator after being heated by rich and poor liquid heat exchanger, and the decarburized liquid after releasing carbon dioxide flows into hydrogen sulfide normal pressure regenerator after being heated by gas -liquid heat exchanger. The absorption tower in the application is connected with carbon dioxide high pressure regenerator first, and after the removal of carbon dioxide in the rich liquid, the regeneration of hydrogen sulfide is carried out through hydrogen sulfide normal pressure regenerator, thereby greatly improving the concentration of hydrogen sulfide, thereby simplifying the operation of subsequent sulfur recovery process, and reducing the investment cost.

Description

Technical Field

[0001] This utility model relates to the technical field of desulfurization equipment for natural gas, syngas and refinery gas, specifically an amine-rich liquid hydrogen sulfide concentration device. Background Technology

[0002] Amine-based H2S removal technology is widely used in the desulfurization processes of natural gas, syngas, and refinery gas. However, amine-based desulfurizing agents absorb CO2 from the process gas along with H2S, leading to a decrease in the H2S concentration in the regenerated acid gas. The high CO2 content in the acid gas makes subsequent sulfur recovery processes difficult to operate and increases investment. For units with a low H2S / CO2 ratio in the process gas, a two-stage absorption-two-stage regeneration process must be used to ensure that the H2S concentration in the regenerated acid gas meets the CLAUS (Clearance of Intake) requirement, or a large amount of fuel gas must be used for co-firing to ensure the thermal balance of the sulfur production unit. Therefore, existing amine-based H2S removal equipment needs to be improved to meet energy-saving and environmental protection requirements. Utility Model Content

[0003] The purpose of this invention is to provide an energy-saving and consumption-reducing device for hydrogen sulfide concentration in amine-rich solutions.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A device for concentrating hydrogen sulfide in an amine-rich solution includes an absorption tower, a rich-lean solution heat exchanger, a high-pressure carbon dioxide regeneration tower, a gas-liquid heat exchanger, an atmospheric pressure hydrogen sulfide regeneration tower, a liquid heater, and a lean solution cooler. The absorption tower has a treated gas outlet at its top, a rich solution outlet at its bottom, a gas inlet on its lower side, and a lean solution outlet on its upper side. Under the action of a first transfer pump, the rich solution containing hydrogen sulfide and carbon dioxide, discharged from the rich solution outlet of the absorption tower, is heated by the rich-lean solution heat exchanger and flows into the high-pressure carbon dioxide regeneration tower. The regenerated carbon dioxide in the rich solution within the high-pressure carbon dioxide regeneration tower is discharged from the carbon dioxide outlet at the top of the high-pressure carbon dioxide regeneration tower. The decarbonized liquid, after releasing carbon dioxide in the high-pressure carbon dioxide regeneration tower, is discharged from the bottom of the high-pressure carbon dioxide regeneration tower. After being heated by a gas-liquid heat exchanger, the decarbonized liquid flows into the hydrogen sulfide atmospheric regeneration tower. The liquid heater is used to heat the decarbonized liquid in the hydrogen sulfide atmospheric regeneration tower. The high-temperature mixed gas that regenerates hydrogen sulfide in the decarbonized liquid in the hydrogen sulfide atmospheric regeneration tower is discharged from the top of the hydrogen sulfide atmospheric regeneration tower. The discharged high-temperature mixed gas flows through a gas-liquid heat exchanger and exchanges heat with the decarbonized liquid. The high-temperature lean liquid, after releasing hydrogen sulfide in the hydrogen sulfide atmospheric regeneration tower, is discharged from the bottom of the hydrogen sulfide atmospheric regeneration tower. After the discharged high-temperature lean liquid flows through a rich-lean liquid heat exchanger and exchanges heat with the rich liquid, it is returned to the absorption tower through the lean liquid discharge inlet under the action of the second transfer pump.

[0005] Furthermore, it also includes a regenerated gas cooler, a gas-liquid separator, and a reflux pump. The mixed gas flowing out of the gas-liquid heat exchanger is cooled by the regenerated gas cooler and then flows into the gas-liquid separator. The condensate in the gas-liquid separator is returned to the hydrogen sulfide atmospheric pressure regeneration tower under the power of the reflux pump. The hydrogen sulfide gas in the gas-liquid separator is discharged from the top of the gas-liquid separator.

[0006] Furthermore, the gas outlet at the lower side of the absorption tower is connected to a first gas-liquid separator via a first pipeline.

[0007] Furthermore, the treated gas outlet at the top of the absorption tower is connected to a second gas-liquid separator via a second pipeline.

[0008] Furthermore, the liquid heater uses high-temperature, high-pressure steam as the heat exchange medium.

[0009] Furthermore, an acid gas absorbent is added to the lean liquid.

[0010] The beneficial effects of this utility model are as follows: The absorption tower in this application is first connected to a high-pressure carbon dioxide regeneration tower to remove carbon dioxide from the rich liquid, and then the hydrogen sulfide is regenerated through a hydrogen sulfide atmospheric pressure regeneration tower, thereby greatly increasing the concentration of hydrogen sulfide extracted and stored, simplifying the operation of subsequent sulfur recovery processes and reducing investment costs.

[0011] This application also adds a rich-lean liquid heat exchanger to make full use of the waste heat in the lean liquid, thereby saving the cost of processing the raw gas. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model.

[0013] In the diagram: 1. Absorption tower; 2. Rich and lean liquid heat exchanger; 3. High-pressure carbon dioxide regeneration tower; 4. Gas-liquid heat exchanger; 5. Atmospheric pressure hydrogen sulfide regeneration tower; 6. Liquid heater; 7. Lean liquid cooler; 8. Treated gas outlet; 9. Rich liquid outlet; 10. Untreated gas inlet; 11. Lean liquid inlet; 12. Carbon dioxide outlet; 13. Regenerated gas cooler; 14. Gas-liquid separator; 15. Reflux pump; 16. First pipeline; 17. First gas-liquid separator; 18. Second pipeline; 19. Second gas-liquid separator; 20. First transfer pump; 21. Second transfer pump. Detailed Implementation

[0014] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0015] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper surface", "lower surface", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "forward", "reverse", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0016] like Figure 1 As shown, an amine-rich liquid hydrogen sulfide concentration device includes an absorption tower 1, a rich-lean liquid heat exchanger 2, a carbon dioxide high-pressure regeneration tower 3, a gas-liquid heat exchanger 4, a hydrogen sulfide atmospheric pressure regeneration tower 5, a liquid heater 6, and a lean liquid cooler 7. The absorption tower 1 has a treated gas outlet 8 at its top, a rich liquid outlet 9 at its bottom, a untreated gas outlet 10 on its lower side, and a lean liquid outlet 11 on its upper side. Under the action of a first transfer pump 20, the rich liquid containing hydrogen sulfide and carbon dioxide discharged from the rich liquid outlet 9 of the absorption tower 1 is heated by the rich-lean liquid heat exchanger 2 and flows into the carbon dioxide high-pressure regeneration tower 3. The carbon dioxide regenerated in the rich liquid in the carbon dioxide high-pressure regeneration tower 3 is discharged from the carbon dioxide outlet 12 at the top of the carbon dioxide high-pressure regeneration tower. The decarbonized liquid, after releasing carbon dioxide, is discharged from the bottom of the high-pressure carbon dioxide regeneration tower 3. After being heated by the gas-liquid heat exchanger 4, the decarbonized liquid flows into the atmospheric pressure hydrogen sulfide regeneration tower 5. The liquid heater 6 is used to heat the decarbonized liquid in the atmospheric pressure hydrogen sulfide regeneration tower 5. The high-temperature mixed gas that regenerates hydrogen sulfide in the decarbonized liquid in the atmospheric pressure hydrogen sulfide regeneration tower 5 is discharged from the top of the tower. The discharged high-temperature mixed gas flows through the gas-liquid heat exchanger 4 and exchanges heat with the decarbonized liquid. The high-temperature lean liquid, after releasing hydrogen sulfide, is discharged from the bottom of the atmospheric pressure hydrogen sulfide regeneration tower 5. After flowing through the rich-lean liquid heat exchanger 2 and exchanging heat with the rich liquid, the discharged high-temperature lean liquid, under the action of the second transfer pump 21, flows back into the absorption tower 1 through the lean liquid discharge inlet 11. An acid gas absorbent, specifically MDEA (methyldiethanolamine), is added to the lean liquid to absorb carbon dioxide and hydrogen sulfide gases.

[0017] It also includes a regenerated gas cooler 13, a gas-liquid separator 14, and a reflux pump 15. The mixed gas flowing out of the gas-liquid heat exchanger 4 is cooled by the regenerated gas cooler 13 and then flows into the gas-liquid separator 14. The condensate in the gas-liquid separator 14 is returned to the hydrogen sulfide atmospheric pressure regeneration tower 5 under the power of the reflux pump 15. The hydrogen sulfide gas in the gas-liquid separator 14 is discharged from the top of the gas-liquid separator.

[0018] The gas outlet 10 at the lower side of the absorption tower 1 is connected to the first gas-liquid separator 17 via the first pipeline 16.

[0019] The treated gas outlet 8 at the top of the absorption tower 1 is connected to a second gas-liquid separator 19 via a second pipeline 18.

[0020] In this embodiment, the liquid heater 6 uses high-temperature, high-pressure steam as the heat exchange medium.

[0021] In this embodiment, the gas to be processed is natural gas.

[0022] Working principle: After passing through the first gas-liquid separator 17, the natural gas enters the absorption tower 1 through the gas discharge inlet 10. It comes into contact with the downward-flowing lean liquid, absorbing H2S and CO2 from the natural gas. The rich liquid, after absorbing H2S and CO2, is discharged from the bottom of the absorption tower 1. After heat exchange in the rich-lean liquid heat exchanger 2, the rich liquid is heated to 100°C and enters the high-pressure carbon dioxide regeneration tower 3, where a large amount of CO2 is flashed out. After washing with a small amount of lean liquid, it is sent out of the system. The decarbonized liquid, after desorbing CO2, has a temperature reduced to approximately 92°C. After heat exchange in the gas-liquid heat exchanger 4, it is heated to 101°C and enters the hydrogen sulfide atmospheric pressure regeneration tower 5. The decarbonized liquid is heated to 120°C by steam in the liquid heater 6, completely regenerating H2S and the remaining CO2. H2S gas, residual CO2 gas, and water vapor form a high-temperature mixed gas, which is discharged from the top of the hydrogen sulfide atmospheric pressure regeneration tower 5. The discharged high-temperature mixed gas flows through the gas-liquid heat exchanger 4 to exchange heat with the decarbonization liquid, and then is cooled by the regeneration gas cooler 13. Afterward, it passes through the gas-liquid separator 14 to remove moisture, yielding regenerated acid gas with an H2S concentration of approximately 25%, which is then sent to the CLAUS sulfur production plant. The CLAUS sulfur production unit uses approximately 900 Nm3 / h of natural gas as a co-firing agent. Using the equipment described in this application for H2S enrichment increases production capacity by 40% and reduces heat consumption by approximately 30%, demonstrating significant energy-saving and consumption-reducing effects.

[0023] Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples, without contradiction. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for concentrating hydrogen sulfide in amine-rich liquid, characterized in that: The system includes an absorption tower, a rich-lean liquid heat exchanger, a high-pressure carbon dioxide regeneration tower, a gas-liquid heat exchanger, a hydrogen sulfide atmospheric pressure regeneration tower, a liquid heater, and a lean liquid cooler. The absorption tower has a treated gas outlet at the top, a rich liquid outlet at the bottom, a gas inlet on the lower side, and a lean liquid outlet on the upper side. Under the action of a first transfer pump, the rich liquid containing hydrogen sulfide and carbon dioxide, discharged from the rich liquid outlet of the absorption tower, is heated by the rich-lean liquid heat exchanger and flows into the high-pressure carbon dioxide regeneration tower. The regenerated carbon dioxide in the rich liquid within the high-pressure carbon dioxide regeneration tower is discharged from the carbon dioxide outlet at the top of the tower. The decarbonized liquid, after releasing carbon dioxide, is discharged from the bottom of the high-pressure carbon dioxide regeneration tower. After being heated by a gas-liquid heat exchanger, the decarbonized liquid flows into the atmospheric regeneration tower for hydrogen sulfide. The liquid heater is used to heat the decarbonized liquid in the atmospheric regeneration tower for hydrogen sulfide. The high-temperature mixed gas that regenerates hydrogen sulfide in the decarbonized liquid in the atmospheric regeneration tower for hydrogen sulfide is discharged from the top of the atmospheric regeneration tower for hydrogen sulfide. The discharged high-temperature mixed gas flows through a gas-liquid heat exchanger and exchanges heat with the decarbonized liquid. The high-temperature lean liquid after releasing hydrogen sulfide in the atmospheric regeneration tower for hydrogen sulfide is discharged from the bottom of the atmospheric regeneration tower for hydrogen sulfide. After the discharged high-temperature lean liquid flows through a rich-lean liquid heat exchanger and exchanges heat with the rich liquid, it is returned to the absorption tower through the lean liquid discharge inlet under the action of the second transfer pump.

2. The amine-rich liquid hydrogen sulfide concentration device according to claim 1, characterized in that: It also includes a regenerated gas cooler, a gas-liquid separator, and a reflux pump. The mixed gas flowing out of the gas-liquid heat exchanger is cooled by the regenerated gas cooler and then flows into the gas-liquid separator. The condensate in the gas-liquid separator is returned to the hydrogen sulfide atmospheric pressure regeneration tower under the power of the reflux pump. The hydrogen sulfide gas in the gas-liquid separator is discharged from the top of the gas-liquid separator.

3. The amine-rich liquid hydrogen sulfide concentration device according to claim 1, characterized in that: The gas outlet at the lower side of the absorption tower is connected to a first gas-liquid separator via a first pipeline.

4. The amine-rich liquid hydrogen sulfide concentration device according to claim 1, characterized in that: The treated gas outlet at the top of the absorption tower is connected to a second gas-liquid separator via a second pipeline.

5. The amine-rich liquid hydrogen sulfide concentration device according to claim 1, characterized in that: The liquid heater uses high-temperature, high-pressure steam as the heat exchange medium.

6. The amine-rich liquid hydrogen sulfide concentration apparatus according to claim 1, characterized in that: An acid gas absorbent is added to the lean liquid.

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