Absorption tower for gas desulfurization

Abstract

The utility model discloses a kind of absorption towers for gas desulfurization, belong to desulfurization equipment technical field, it includes tower body, plate microchannel unit, gas-liquid separation hydrophobic membrane and gas-liquid separation hydrophilic membrane, the top of tower body is equipped with the gas outlet of having been handled, the bottom of tower body is equipped with rich liquid outlet, the lower side of tower body is equipped with the gas inlet of being handled, the upper side of tower body is equipped with the liquid outlet of being lean, plate microchannel unit is located in tower body, the gas inlet of being handled is located below plate microchannel unit, the liquid outlet of being lean is located above plate microchannel unit, gas-liquid separation hydrophobic membrane is located in tower body and close to the gas outlet of having been handled, gas-liquid separation hydrophilic membrane is located in tower body and close to rich liquid outlet. Plate microchannel unit is additionally arranged in the tower body of the application, the purpose is to shorten the contact time of gas to be handled and absorbent, H2S has been completely absorbed by absorbent, CO2 is "intercepted" in gas phase due to insufficient reaction time, to improve the purpose of the concentration of regenerated H2S.

Description

Technical Field

[0001] This utility model relates to the field of desulfurization equipment technology, specifically an absorption tower for desulfurizing gases such as natural gas, syngas, and refinery gas. 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 absorption tower for gas desulfurization that can increase the concentration of regenerated H2S.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: An absorption tower for gas desulfurization includes a tower body, a plate-type microchannel unit, a gas-liquid separation hydrophobic membrane, and a gas-liquid separation hydrophilic membrane. The top of the tower body has a treated gas outlet, the bottom of the tower body has a rich liquid outlet, the lower side of the tower body has a gas-to-be-treated inlet, and the upper side of the tower body has a lean liquid outlet. The plate-type microchannel unit is disposed within the tower body, the gas-to-be-treated inlet is located below the plate-type microchannel unit, and the lean liquid outlet is located above the plate-type microchannel unit. The gas-liquid separation hydrophobic membrane is disposed within the tower body and close to the treated gas outlet, and the gas-liquid separation hydrophilic membrane is disposed within the tower body and close to the rich liquid outlet.

[0005] Furthermore, the plate-type microchannel unit adopts a pull-out modular plate-type microchannel. The tower body has a pull-out opening on its side wall, and the tower body is equipped with load-bearing guide rails on both sides of the pull-out opening. The pull-out modular plate-type microchannel extends from the pull-out opening and is supported on the load-bearing guide rails.

[0006] Furthermore, the plate-type microchannel unit includes a square frame and multiple corrosion-resistant plates, which are stacked side by side in the square frame, and the surface of each corrosion-resistant plate is provided with a row of vertical microchannels.

[0007] Furthermore, protrusions are distributed on the inner wall surface of the vertical microchannel. These protrusions are used to disrupt the gas-liquid boundary layer, increase turbulence, and thus improve the mass transfer coefficient.

[0008] Furthermore, the outer side of the square frame is provided with a pull-out handle, and the bottom of both sides of the square frame is provided with rollers, which are supported on the support rail and can roll along the support rail.

[0009] Furthermore, the corrosion-resistant plate is made of silicon carbide ceramic or PTFE material.

[0010] Furthermore, the diameter of the vertical microchannel is 150-300μm and the length is 4-6cm.

[0011] Furthermore, the gas-liquid separation hydrophobic membrane is a pull-out modular gas-liquid separation hydrophobic membrane, and the gas-liquid separation hydrophilic membrane is a pull-out modular gas-liquid separation hydrophilic membrane. The tower body has an upper pull-out port and a lower pull-out port on its side wall. The tower body has upper support guide rails on both sides of the upper pull-out port and lower support guide rails on both sides of the lower pull-out port. The pull-out modular gas-liquid separation hydrophobic membrane extends from the upper pull-out port and is supported on the upper support guide rail, and the pull-out modular gas-liquid separation hydrophilic membrane extends from the lower pull-out port and is supported on the lower support guide rail.

[0012] Furthermore, the gas-liquid separation hydrophobic membrane includes a hydrophobic membrane body, which is made of PTFE material. The surface of the hydrophobic membrane body is distributed with membrane pores, and the inner diameter of the membrane pores is 0.25-0.35μm.

[0013] Furthermore, the gas-liquid separation hydrophilic membrane includes a hydrophilic membrane body, which is made of PVDF material. The surface of the hydrophilic membrane body is distributed with membrane pores, and the inner diameter of the membrane pores is 0.55-0.65μm.

[0014] The beneficial effects of this utility model are as follows: This application adds a plate-type microchannel unit inside the tower. The purpose of this design is to shorten the contact time between natural gas (gas to be treated) and absorbent. Because H2S reacts quickly while CO2 reacts slowly, the short diffusion path length of the microchannel is only 4-6 cm, thereby controlling the gas-liquid contact time to within 50 ms. Within 50 ms, H2S has been completely absorbed by the absorbent, while the reaction time of CO2 is 100 ms. CO2 is "retained" in the gas phase due to insufficient reaction time, thereby increasing the regenerated H2S concentration. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 The side view shown; Figure 3 for Figure 1 The diagram shows the structure of the plate-type microchannel unit. Figure 4 for Figure 3 The diagram shows the structure of the corrosion-resistant plate. Figure 5 for Figure 4 The top view shown.

[0016] In the diagram: 1. Tower body; 2. Plate-type microchannel unit; 3. Gas-liquid separation hydrophobic membrane; 4. Gas-liquid separation hydrophilic membrane; 5. Treated gas outlet; 6. Rich liquid outlet; 7. Untreated gas inlet; 8. Lean liquid inlet; 9. Pull-out port; 10. Support rail; 11. Upper pull-out port; 12. Lower pull-out port; 13. Upper support rail; 14. Lower support rail; 15. Square frame; 16. Corrosion-resistant plate; 17. Vertical microchannel; 18. Protrusion; 19. Pull-out handle; 20. Roller. Detailed Implementation

[0017] 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.

[0018] 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.

[0019] like Figure 1 , Figure 2 As shown, an absorption tower for gas desulfurization includes a tower body 1, a plate-type microchannel unit 2, a gas-liquid separation hydrophobic membrane 3, and a gas-liquid separation hydrophilic membrane 4. The top of the tower body 1 is provided with a treated gas outlet 5, the bottom of the tower body 1 is provided with a rich liquid outlet 6, the lower side of the tower body 1 is provided with a gas-to-be-treated inlet 7, and the upper side of the tower body 1 is provided with a lean liquid outlet 8. The plate-type microchannel unit 2 is located inside the tower body 1. The gas-to-be-treated inlet 7 is located below the plate-type microchannel unit 2, and the lean liquid outlet 8 is located above the plate-type microchannel unit 2. The gas-liquid separation hydrophobic membrane 3 is located inside the tower body 1 and close to the treated gas outlet 5, and the gas-liquid separation hydrophilic membrane 4 is located inside the tower body 1 and close to the rich liquid outlet 6.

[0020] The gas-liquid separation hydrophobic membrane 3 is a pull-out modular gas-liquid separation hydrophobic membrane, and the gas-liquid separation hydrophilic membrane 4 is a pull-out modular gas-liquid separation hydrophilic membrane. The tower body 1 has an upper pull-out port 11 and a lower pull-out port 12 on its side wall. Upper support rails 13 are located inside the tower body 1 on both sides of the upper pull-out port 11, and lower support rails 14 are located inside the tower body 1 on both sides of the lower pull-out port 12. The pull-out modular gas-liquid separation hydrophobic membrane 3 extends from the upper pull-out port 11 and is supported on the upper support rail 13, and the pull-out modular gas-liquid separation hydrophilic membrane extends from the lower pull-out port 12 and is supported on the lower support rail 14. The pull-out modular design facilitates the installation and replacement of the gas-liquid separation hydrophobic membrane 3 and the gas-liquid separation hydrophilic membrane 4, greatly simplifying subsequent maintenance procedures.

[0021] The gas-liquid separation hydrophobic membrane includes a hydrophobic membrane body made of PTFE material, with membrane pores distributed on its surface, the inner diameter of which is 0.25-0.35 μm. The gas-liquid separation hydrophilic membrane includes a hydrophilic membrane body made of PVDF material, with membrane pores distributed on its surface, the inner diameter of which is 0.55-0.65 μm.

[0022] like Figure 3 , Figure 4 , Figure 5 As shown, the plate-type microchannel unit 2 adopts a pull-out modular plate-type microchannel. The tower body 1 has a pull-out opening 9 on its side wall. The tower body 1 is provided with a bearing guide rail 10 on both sides of the pull-out opening 9. The pull-out modular plate-type microchannel extends from the pull-out opening 9 and is supported on the bearing guide rail 10.

[0023] Specifically, the plate-type microchannel unit 2 includes a square frame 15 and multiple corrosion-resistant plates 16. The multiple corrosion-resistant plates 16 are stacked side by side in the square frame 15. A row of vertical microchannels 17 is provided on the surface of each corrosion-resistant plate 16. Protrusions 18 are distributed on the inner wall of each vertical microchannel 17. The protrusions 18 are used to disrupt the gas-liquid boundary layer, increase turbulence, and improve the mass transfer coefficient. A pull-out handle 19 is provided on the outer side of the square frame 15, and rollers 20 are provided on the bottom of both sides of the square frame 15. The rollers 20 are supported on the support rail 10 and can roll along the support rail 10. The corrosion-resistant plates 16 are made of silicon carbide ceramic or PTFE material. The diameter of the vertical microchannels is 150-300μm and the length is 4-6cm.

[0024] Working Principle: This application adds a plate-type microchannel unit 2 to the tower body. The vertical microchannels in the plate-type microchannel unit have a diameter of 150-300μm and a length of 4-6cm. This design aims to shorten the contact time between natural gas (gas to be treated) and the absorbent. Because H2S reacts quickly while CO2 reacts slowly, the mechanism is that the short diffusion path length of the microchannel is only 4-6cm, thus controlling the gas-liquid contact time to within 50ms. Within 50ms, H2S is completely absorbed by the absorbent, while CO2 requires a reaction time of 100ms. Due to insufficient reaction time, CO2 is "retained" in the gas phase. Based on the plate-type microchannel unit, by controlling the gas flow rate of natural gas, the gas-liquid contact time is controlled to within 50ms, preventing CO2 from reacting and being absorbed in the hydrogen sulfide absorption chamber 14. The CO2 in the gas phase is sent to the carbon dioxide absorption chamber 13 for absorption treatment, thereby achieving acid gas classification treatment and increasing the regenerated H2S concentration.

[0025] To prevent CO2 in the gas phase from being discharged from the rich liquid outlet 6 along with the rich liquid, a gas-liquid separation hydrophilic membrane 4 is added near the rich liquid outlet 6. The gas-liquid separation hydrophilic membrane 4 has a barrier effect on the gas phase. If the gas phase is discharged from the rich liquid outlet 6 along with the rich liquid, it will give the CO2 in the gas phase enough reaction time, and it will eventually be absorbed by the absorbent.

[0026] In addition, the treated gas will carry a certain amount of liquid phase after desulfurization. Before the treated gas is discharged from the tower, gas-liquid separation is required. Therefore, a gas-liquid separation hydrophobic membrane 3 is added inside the tower 1 and near the treated gas outlet 5.

[0027] The plate-type microchannel unit 2, the gas-liquid separation hydrophobic membrane 3, and the gas-liquid separation hydrophilic membrane 4 in this invention all adopt a pull-out modular design, which greatly facilitates installation and subsequent maintenance.

[0028] 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. An absorption tower for gas desulfurization, characterized in that: The device includes a tower body, a plate-type microchannel unit, a hydrophobic membrane for gas-liquid separation, and a hydrophilic membrane for gas-liquid separation. The top of the tower body has a treated gas outlet, the bottom of the tower body has a rich liquid outlet, the lower side of the tower body has a gas-to-be-treated inlet, and the upper side of the tower body has a lean liquid outlet. The plate-type microchannel unit is located inside the tower body, with the gas-to-be-treated inlet located below the plate-type microchannel unit and the lean liquid outlet located above the plate-type microchannel unit. The hydrophobic membrane for gas-liquid separation is located inside the tower body and close to the treated gas outlet, and the hydrophilic membrane for gas-liquid separation is located inside the tower body and close to the rich liquid outlet.

2. The gas desulfurization absorption tower according to claim 1, characterized in that: The plate-type microchannel unit adopts a pull-out modular plate-type microchannel. The tower body has a pull-out opening on its side wall. The tower body is equipped with load-bearing guide rails on both sides of the pull-out opening. The pull-out modular plate-type microchannel extends from the pull-out opening and is supported on the load-bearing guide rails.

3. The gas desulfurization absorption tower according to claim 2, characterized in that: The plate-type microchannel unit includes a square frame and multiple corrosion-resistant plates. The multiple corrosion-resistant plates are stacked side by side in the square frame, and a row of vertical microchannels is provided on the surface of the corrosion-resistant plates.

4. The gas desulfurization absorption tower according to claim 3, characterized in that: The inner wall of the vertical microchannel is covered with protrusions.

5. The gas desulfurization absorption tower according to claim 4, characterized in that: The outer side of the square frame is provided with a pull-out handle, and the bottom of both sides of the square frame is provided with rollers. The rollers are supported on the support rail and can roll along the support rail.

6. The gas desulfurization absorption tower according to claim 5, characterized in that: The corrosion-resistant plate is made of silicon carbide ceramic or PTFE material.

7. The absorption tower for gas desulfurization according to claim 6, characterized in that: The vertical microchannels have a diameter of 150-300μm and a length of 4-6cm.

8. The absorption tower for gas desulfurization according to claim 1, characterized in that: The gas-liquid separation hydrophobic membrane is a pull-out modular gas-liquid separation hydrophobic membrane, and the gas-liquid separation hydrophilic membrane is a pull-out modular gas-liquid separation hydrophilic membrane. The tower body has an upper pull-out port and a lower pull-out port on its side wall. The tower body has upper support guide rails on both sides of the upper pull-out port and lower support guide rails on both sides of the lower pull-out port. The pull-out modular gas-liquid separation hydrophobic membrane extends from the upper pull-out port and is supported on the upper support guide rail, and the pull-out modular gas-liquid separation hydrophilic membrane extends from the lower pull-out port and is supported on the lower support guide rail.

9. The gas desulfurization absorption tower according to claim 8, characterized in that: The gas-liquid separation hydrophobic membrane includes a hydrophobic membrane body made of PTFE material. The surface of the hydrophobic membrane body is distributed with membrane pores, the inner diameter of which is 0.25-0.35 μm.

10. The gas desulfurization absorption tower according to claim 8, characterized in that: The gas-liquid separation hydrophilic membrane includes a hydrophilic membrane body, which is made of PVDF material. The surface of the hydrophilic membrane body is distributed with membrane pores, and the inner diameter of the membrane pores is 0.55-0.65μm.

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