A ship exhaust gas desulfurization device and desulfurization method

Abstract

The present invention provides a ship exhaust gas desulfurization device and a desulfurization method, which include a sulfur-containing ship exhaust gas pretreatment system, a seawater pretreatment system, a membrane contactor, and a seawater post-treatment system; the outlet end of the sulfur-containing ship exhaust gas pretreatment system is connected to the shell-side inlet end of the membrane contactor for sending the dust- and oil-removed exhaust gas into the shell side of the membrane contactor; the outlet end of the seawater pretreatment system is connected to the tube-side inlet end of the membrane contactor for sending the pretreated seawater into the tube side of the membrane contactor; the membrane contactor is a membrane contactor filled with polytetrafluoroethylene hollow fiber hydrophobic microporous membranes; the inlet end of the seawater post-treatment system is connected to the tube-side outlet end of the membrane contactor for post-treating the seawater after absorbing sulfur dioxide and oxidizing sulfite into sulfate. The ship exhaust gas desulfurization device described in the present invention has a high integration degree, a compact volume, and a high desulfurization efficiency, can achieve efficient desulfurization of ship exhaust gas, and has good application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of tail gas purification, and in particular relates to a ship tail gas desulfurization device and a desulfurization method. Background Art

[0002] The main processes of current international desulfurization technologies include gypsum flue gas desulfurization method, rotary spray drying desulfurization method, seawater desulfurization method, etc. Among them, the seawater desulfurization method is a relatively mature desulfurization technology developed in recent decades, and was first proposed by the United States in the 1960s. This method generally adopts an absorption tower process, and makes full use of the acid-base buffering capacity of natural seawater and the strong ability to neutralize acidic gases to effectively remove SO2 in the flue gas. The seawater desulfurization process is simple, highly efficient, environmentally friendly, reliable and economical, and has less pollution to the ecological environment. It is considered to be one of the more ideal ship tail gas treatment methods. However, it also has disadvantages such as large equipment occupancy space and poor effect when treating the tail gas emitted from the combustion of high-sulfur fuel. Once the above problems are solved, it will greatly promote the application of this technology in ship tail gas treatment.

[0003] The membrane contactor technology is a new desulfurization and decarbonization technology developed in recent years, which is a membrane process that realizes mass transfer between phases without direct contact between two phases. In this process, the microporous membrane only acts as an interface between two phases, separating the ship tail gas phase and the absorbent seawater liquid phase. SO2 in the gas phase can pass through the membrane contact interface and enter the absorbent phase to be carried away, achieving the purpose of desulfurization. Compared with the traditional absorption tower process, the membrane contactor method has many outstanding advantages, such as greatly increasing the specific surface area, improving the absorption effect, reducing the equipment height and volume, reducing the operation cost, etc. In addition, the membrane contact method has more flexible operability, does not depend on the gas-liquid phase flow rate, has stable performance, and does not have disadvantages such as foaming, entrainment and flooding, and has obvious advantages and good application prospects in the field of ship tail gas desulfurization and purification.

[0004] Chinese invention patents CN106076072A and CN110624399A use ceramic membranes for ship tail gas desulfurization, but the size of ceramic membranes is generally large (the outer diameter is usually about several millimeters or even several centimeters), and the advantage of the large specific surface area of the membrane contactor is not utilized, and the price is expensive. In addition, due to the incomplete combustion of ship diesel fuel, the contained solid small particles and oil droplets will inevitably contaminate the membrane pores, affecting the diffusion and mass transfer of SO2. On the other hand, before the seawater after absorbing SO2 is discharged, the sulfite needs to be oxidized to sulfate. The conventional aeration method has low efficiency, long treatment time, and requires a large volume of seawater storage tank, which affects the land occupation and practicability of the whole system. Summary of the Invention

[0005] In view of this, to solve the above problems, the present invention proposes a ship exhaust gas desulfurization device with high integration, compact volume, high desulfurization efficiency and good effect. At the same time, a desulfurization method using the ship exhaust gas desulfurization device is provided, which can achieve efficient desulfurization of ship exhaust gas.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows:

[0007] A ship exhaust gas desulfurization device includes: a sulfur-containing ship exhaust gas pretreatment system, a seawater pretreatment system, a membrane contactor and a seawater post-treatment system;

[0008] The outlet end of the sulfur-containing ship exhaust gas pretreatment system is connected to the shell-side inlet end of the membrane contactor for sending the dust- and oil-removed exhaust gas into the shell side of the membrane contactor;

[0009] The outlet end of the seawater pretreatment system is connected to the tube-side inlet end of the membrane contactor for sending the pretreated seawater into the tube side of the membrane contactor;

[0010] The membrane contactor is a membrane contactor filled with polytetrafluoroethylene hollow fiber hydrophobic microporous membranes, which can provide a very large volume specific surface area and gas-liquid mass transfer efficiency;

[0011] The inlet end of the seawater post-treatment system is connected to the tube-side outlet end of the membrane contactor for post-treating the seawater after absorbing sulfur dioxide and oxidizing sulfite into sulfate.

[0012] Further, the sulfur-containing ship exhaust gas pretreatment system includes a dust collector, an oil removal filter and a fan I connected in sequence through pipelines, and the outlet end of the fan I is connected to the shell-side inlet end of the membrane contactor.

[0013] After the sulfur-containing ship exhaust gas removes solid particles such as dust in the flue gas through the dust collector, it enters the oil removal filter to remove the incompletely burned liquid oil droplets in the flue gas, avoiding the pollution and blockage of the hydrophobic microporous membranes in the subsequent membrane contactor. Then, after being pressurized by the fan I, it enters the shell side of the membrane contactor;

[0014] Further, the dust collector can remove solid particles with a particle size of more than 0.1 μm and the removal efficiency is higher than 99%;

[0015] Further, the oil removal filter can remove incompletely burned liquid oil droplets with a particle size of more than 0.01 μm, and the removal efficiency is higher than 99.5%.

[0016] Further, the seawater pretreatment system includes a sand filtration unit, a seawater pump I, a microfiltration membrane unit, and a seawater storage tank connected in sequence through pipelines; the seawater storage tank sends the pretreated seawater into the tube side of the membrane contactor through a seawater pump II.

[0017] After the seawater is pretreated by the sand filtration unit and the microfiltration unit, it enters the seawater storage tank, and then can be pressurized by the second seawater pump and enter the tube side of the membrane contactor.

[0018] Furthermore, the sand filtration unit can remove suspended solids with a size above 10 μm;

[0019] Furthermore, the pore size of the microfiltration membrane in the microfiltration membrane unit is 0.1 μm.

[0020] Furthermore, the outer diameter of the membrane filaments of the polytetrafluoroethylene hollow fiber hydrophobic microporous membrane filled in the membrane contactor is 0.4 - 1.0 mm, the inner diameter is 0.2 - 0.6 mm, the porosity is 40 - 65%, the average pore size is 0.05 - 0.25 μm, and the static water contact angle is greater than ;

[0021] Furthermore, the volume specific surface area of the membrane contactor is higher than 1500 m 2 / m 3 .

[0022] Furthermore, the seawater post-treatment system includes a seawater pool, an aeration membrane distributed at the bottom of the seawater pool, and a second blower for introducing air into the aeration membrane; the outlet end of the tube side of the membrane contactor is connected to the inlet end of the seawater pool.

[0023] The seawater after absorbing sulfur dioxide enters the seawater pool, and the bottom of the seawater pool is provided with an aeration membrane. The blower introduces air into the aeration membrane to generate a large number of fine bubbles in the seawater pool to oxidize sulfite into sulfate.

[0024] Furthermore, the aeration membrane is a polytetrafluoroethylene hollow fiber aeration membrane with a hydrophilic modified outer surface and a still hydrophobic inner surface; preferably, the outer diameter of the membrane filaments in the aeration membrane is 1.0 - 2.0 mm, the inner diameter is 0.5 - 1.2 mm, the porosity is 50 - 70%, the average pore size is 0.1 - 0.5 μm, the static water contact angle of the outer surface is lower than , and the static water contact angle of the inner surface is higher than .

[0025] Furthermore, the seawater pool is provided with two accommodation spaces, and the aeration membrane is distributed at the bottom of both accommodation spaces. The liquid level of the accommodation space on the side close to the inlet end of the seawater pool is higher than the liquid level of the accommodation space on the side close to the outlet end of the seawater pool, and the seawater in the high liquid level accommodation space can flow into the low liquid level accommodation space.

[0026] A desulfurization method using a ship exhaust gas desulfurization device includes the following:

[0027] (1)The sulfur-containing ship exhaust gas to be treated is sent into the sulfur-containing ship exhaust gas pretreatment system. After dust removal and oil removal, it is pressurized to 20 - 80 kPa and sent into the shell side of the membrane contactor;

[0028] (2)Seawater is sent into the seawater pretreatment system. After sand filtration and microfiltration, it is pressurized to 30 - 120 kPa and sent into the tube side of the membrane contactor;

[0029] (3)Gas-liquid mass transfer occurs between the exhaust gas flowing in the shell side of the membrane contactor and the seawater flowing in the tube side of the membrane contactor. Sulfur dioxide in the exhaust gas is absorbed by the seawater, and the liquid phase pressure on the seawater side is maintained 10 - 40 kPa higher than the gas phase pressure on the exhaust gas side; The treated exhaust gas is discharged from the outlet end of the shell side of the membrane contactor, and the seawater after absorbing sulfur dioxide is discharged from the outlet end of the tube side of the membrane contactor and enters the seawater post-treatment system;

[0030] (4)The seawater that has absorbed sulfur dioxide enters the seawater pool of the seawater post-treatment system. An aeration membrane is distributed in the seawater pool. Air with a pressure of 20 - 80 kPa is introduced into the aeration membrane, and a large number of fine bubbles are generated in the seawater pool to oxidize sulfite to sulfate.

[0031] Compared with the prior art, the ship exhaust gas desulfurization device and desulfurization method of the present invention have the following advantages:

[0032] (1)Compared with the traditional absorption tower desulfurization process, the ship exhaust gas desulfurization device and method of the present invention have more flexible operability, do not depend on the gas-liquid flow rate, have stable performance, and do not have drawbacks such as foaming, entrainment, and flooding. It can significantly improve the absorption effect, reduce the height and volume of the equipment, and reduce the operation cost;

[0033] (2)Compared with the ceramic membrane contactor, the polytetrafluoroethylene hollow fiber membrane used in the present invention is small in size, large in volume specific surface area, the equipment is more compact and efficient, and the price is lower;

[0034] (3)The ship exhaust gas desulfurization device and method of the present invention integrate a variety of membrane technologies, have high efficiency and modular design, can achieve high-efficiency desulfurization of ship exhaust gas, and the desulfurization efficiency is higher than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0036] Figure 1 It is a schematic structural diagram of the ship exhaust gas desulfurization device described in the embodiment of the present invention.

[0037] Description of the reference numerals:

[0038] 1 - Sulfur - containing ship exhaust gas pretreatment system; 2 - Seawater pretreatment system; 3 - Membrane contactor; 4 - Seawater post - treatment system; 5 - Dust collector; 6 - Oil - removing filter; 7 - Fan 1; 8 - Sand filtration unit; 9 - Seawater pump 1; 10 - Microfiltration membrane unit; 11 - Seawater storage tank; 12 - Seawater pump 2; 13 - Seawater pool; 14 - Aeration membrane; 15 - Fan 2; 16 - Seawater pump 3. Detailed implementation manners

[0039] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention may be combined with each other.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0041] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0042] The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0043] The following ship exhaust gas desulfurization device is used in the following embodiments:

[0044] As Figure 1 shown, a ship exhaust gas desulfurization device includes a sulfur - containing ship exhaust gas pretreatment system 1, a seawater pretreatment system 2, a membrane contactor 3, and a seawater post - treatment system 4;

[0045] Among them, the sulfur-containing ship exhaust gas pretreatment system 1 includes a dust remover 5, an oil removal filter 6, and a first fan 7 connected in sequence through pipelines; the outlet end of the first fan 7 is connected to the shell side inlet end of the membrane contactor 3; the dust remover 5 can remove solid particles with a particle size of more than 0.1 μm and the removal efficiency is higher than 99%; the oil removal filter 6 can remove incompletely burned liquid oil droplets with a particle size of more than 0.01 μm and the removal efficiency is higher than 99.5%;

[0046] The seawater pretreatment system 2 includes a sand filtration unit 8, a first seawater pump 9, a microfiltration membrane unit 10, and a seawater storage tank 11 connected in sequence through pipelines; the sand filtration unit 8 can remove suspended substances with a size of more than 10 μm; the pore diameter of the microfiltration membrane in the microfiltration membrane unit 10 is 0.1 μm; the seawater storage tank 11 sends the pretreated seawater into the tube side of the membrane contactor 3 through a second seawater pump 12;

[0047] The membrane contactor 3 is a membrane contactor 3 filled with polytetrafluoroethylene hollow fiber hydrophobic microporous membranes; the outer diameter of the membrane filaments of the polytetrafluoroethylene hollow fiber hydrophobic microporous membranes filled in the membrane contactor 3 is 0.4 - 1.0 mm, the inner diameter is 0.2 - 0.6 mm, the porosity is 40 - 65%, the average pore diameter is 0.05 - 0.25 μm, and the static water contact angle is greater than ; the volume specific surface area of the membrane contactor 3 is higher than 1500 m 2 / m 3 ;

[0048] The seawater post-treatment system 4 includes a seawater pool 13, an aeration membrane 14 distributed at the bottom of the seawater pool 13, and a second fan 15 for introducing air into the aeration membrane 14; the tube side outlet end of the membrane contactor 3 is connected to the inlet end of the seawater pool 13, and the outlet end of the seawater pool 13 discharges liquid through a third seawater pump 16; the seawater pool 13 has two accommodation spaces, and the bottom of both accommodation spaces is distributed with aeration membranes 14. The liquid level of the accommodation space on the side close to the inlet end of the seawater pool 13 is higher than the liquid level of the accommodation space on the side close to the outlet end of the seawater pool. The seawater in the high liquid level accommodation space can flow into the low liquid level accommodation space; the aeration membrane 14 is a polytetrafluoroethylene hollow fiber aeration membrane 14 with a hydrophilic modified outer surface and still hydrophobic inner surface; the outer diameter of the membrane filaments in the aeration membrane 14 is 1.0 - 2.0 mm, the inner diameter is 0.5 - 1.2 mm, the porosity is 50 - 70%, the average pore diameter is 0.1 - 0.5 μm, the outer surface static water contact angle is lower than and the inner surface static water contact angle is higher than .

[0049] Example 1

[0050] The ship exhaust gas desulfurization device adopted in this embodiment desulfurizes the ship exhaust gas. Among them, the outer diameter of the polytetrafluoroethylene hollow fiber hydrophobic microporous membrane filled in the membrane contactor is 0.8 mm, the inner diameter is 0.4 mm, the porosity is 50%, the average pore diameter is 0.10 μm, and the static water contact angle , the volume specific surface area of the membrane contactor is 2200 m 2 / m 3 ; the outer diameter of the membrane filaments in the aeration membrane is 1.2 mm, the inner diameter is 0.6 mm, the porosity is 60%, the average pore diameter is 0.25 μm, the static water contact angle on the outer surface is , and the static water contact angle on the inner surface is .

[0051] The desulfurization process is as follows:

[0052] (1) The concentration of SO2 in the ship exhaust gas to be treated is 700 ppm. The sulfur-containing ship exhaust gas to be treated is sent into the sulfur-containing ship exhaust gas pretreatment system; a dust collector is used to remove solid particles such as dust with a particle size of more than 0.1 μm in the exhaust gas, and the removal efficiency is 99.7%; the exhaust gas after dust removal passes through an oil removal filter to remove unburned liquid oil droplets with a particle size of more than 0.01 μm in the exhaust gas, and the removal efficiency is higher than 99.9%; after dust and oil removal, it is pressurized to 40 kPa by a blower and sent into the shell side of the membrane contactor;

[0053] (2) The seawater is sent into the seawater pretreatment system. The seawater passes through the sand filtration unit and the microfiltration membrane unit to remove suspended solids with a size of more than 10 μm and suspended solids with a size of more than 0.1 μm in the water respectively; the pretreated seawater is pressurized to 60 kPa by a seawater pump two and sent into the tube side of the membrane contactor;

[0054] (3) The seawater flowing in the tube side of the membrane contactor absorbs SO2 in the exhaust gas flowing in the shell side of the membrane contactor through the mass transfer interface provided by the microporous membrane. The concentration of SO2 in the treated exhaust gas is reduced to 21 ppm, and the desulfurization efficiency reaches 97%;

[0055] (4) The seawater that has absorbed SO2 enters the seawater tank. The liquid level in the high liquid level accommodation space of the seawater tank is 0.5 m higher than the liquid level in the low liquid level accommodation space; the bottom of the seawater tank is provided with an aeration membrane; a blower two introduces air into the aeration membrane at a pressure of 40 kPa, and a large number of fine bubbles are produced in the seawater tank to oxidize sulfite into sulfate and then discharged by a seawater pump three.

[0056] Example 2

[0057] The ship exhaust gas desulfurization device adopted in this embodiment desulfurizes the ship exhaust gas. Among them, the outer diameter of the polytetrafluoroethylene hollow fiber hydrophobic microporous membrane filled in the membrane contactor is 1.0 mm, the inner diameter is 0.6 mm, the porosity is 53%, the average pore diameter is 0.15 μm, and the static water contact angle , the volumetric specific surface area of the membrane contactor is 1800 m 2 / m 3 ; the outer diameter of the membrane filaments in the aeration membrane is 1.6 mm, the inner diameter is 0.8 mm, the porosity is 65%, the average pore diameter is 0.4 μm, and the static water contact angle on the outer surface is , and the static water contact angle on the inner surface is .

[0058] The desulfurization process is as follows:

[0059] (1) The concentration of SO2 in the ship exhaust gas to be treated is 450 ppm. The sulfur-containing ship exhaust gas to be treated is sent into the sulfur-containing ship exhaust gas pretreatment system; a dust collector is used to remove solid particles such as dust with a particle size above 0.1 μm in the exhaust gas, and the removal efficiency is 99.5%; the exhaust gas after dust removal is passed through an oil removal filter to remove unburned liquid oil droplets with a particle size above 0.01 μm in the exhaust gas, and the removal efficiency is higher than 99.8%; after dust and oil removal, it is pressurized to 30 kPa by a blower and sent into the shell side of the membrane contactor;

[0060] (2) Seawater is sent into the seawater pretreatment system. The seawater passes through a sand filtration unit and a microfiltration membrane unit to remove suspended solids with a size above 10 μm and suspended solids with a size above 0.1 μm in the water respectively; the pretreated seawater is pressurized to 40 kPa by a seawater pump two and sent into the tube side of the membrane contactor;

[0061] (3) The seawater flowing in the tube side of the membrane contactor absorbs SO2 in the exhaust gas flowing in the shell side of the membrane contactor through the mass transfer interface provided by the microporous membrane. The concentration of SO2 in the treated exhaust gas is reduced to 18 ppm, and the desulfurization efficiency reaches 96%;

[0062] (4) The seawater that has absorbed SO2 enters the seawater pool. The liquid level in the high liquid level accommodation space of the seawater pool is 0.3 m higher than the liquid level in the low liquid level accommodation space; an aeration membrane is arranged at the bottom of the seawater pool; a blower two introduces air into the aeration membrane at a pressure of 40 kPa, and a large number of fine bubbles are produced in the seawater pool to oxidize sulfite into sulfate and then discharged by a seawater pump three.

[0063] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A ship exhaust gas desulfurization device, characterized in that: Including: A sulfur-containing ship exhaust gas pretreatment system, a seawater pretreatment system, a membrane contactor, and a seawater post-treatment system; The outlet end of the sulfur-containing ship exhaust gas pretreatment system is connected to the shell-side inlet end of the membrane contactor for sending the dust- and oil-removed exhaust gas into the shell side of the membrane contactor; the sulfur-containing ship exhaust gas pretreatment system includes a dust collector, an oil removal filter, and a blower I connected in sequence through pipelines, and the outlet end of the blower I is connected to the shell-side inlet end of the membrane contactor; the oil removal filter can remove unburned liquid oil droplets with a particle size above 0.01 μm, and the removal efficiency is higher than 99.5%; The outlet end of the seawater pretreatment system is connected to the tube-side inlet end of the membrane contactor for sending the pretreated seawater into the tube side of the membrane contactor; The membrane contactor is a membrane contactor filled with polytetrafluoroethylene hollow fiber hydrophobic microporous membranes; The inlet end of the seawater post-treatment system is connected to the tube-side outlet end of the membrane contactor, and is used for post-treating the seawater after absorbing sulfur dioxide to oxidize sulfite into sulfate. The seawater post-treatment system includes a seawater pool, an aeration membrane distributed at the bottom of the seawater pool, and a second blower for introducing air into the aeration membrane. The tube-side outlet end of the membrane contactor is connected to the inlet end of the seawater pool. The aeration membrane is a polytetrafluoroethylene hollow fiber aeration membrane with a hydrophilic-modified outer surface and a still hydrophobic inner surface. The outer diameter of the membrane filaments in the aeration membrane is 1.0 - 2.0 mm, the inner diameter is 0.5 - 1.2 mm, the porosity is 50 - 70%, the average pore diameter is 0.1 - 0.5 μm, and the static water contact angle of the outer surface is lower than , and the static water contact angle of the inner surface is higher than .

2. The ship exhaust gas desulfurization device according to claim 1, characterized in that: The dust collector can remove solid particles with a particle size above 0.1 μm and the removal efficiency is higher than 99%; 3. The ship exhaust gas desulfurization device according to claim 1, characterized in that: The seawater pretreatment system includes a sand filtration unit, a seawater pump I, a microfiltration membrane unit, and a seawater storage tank connected in sequence through pipelines; the seawater storage tank sends the pretreated seawater into the tube side of the membrane contactor through a seawater pump II.

4. The ship exhaust gas desulfurization device according to claim 3, characterized in that: The sand filtration unit can remove suspended solids with a size above 10 μm.

5. The ship exhaust gas desulfurization device according to claim 3, characterized in that: The pore size of the microfiltration membrane in the microfiltration membrane unit is 0.1 μm.

6. The ship exhaust gas desulfurization device according to claim 1, characterized in that: The outer diameter of the membrane filaments of the polytetrafluoroethylene hollow fiber hydrophobic microporous membrane filled in the membrane contactor is 0.4 - 1.0 mm, the inner diameter is 0.2 - 0.6 mm, the porosity is 40 - 65%, the average pore diameter is 0.05 - 0.25 μm, and the static water contact angle is greater than .

7. The ship exhaust gas desulfurization device according to claim 1, characterized in that: The volume specific surface area of the membrane contactor is higher than 1500 m 2 / m 3 .

8. The ship exhaust gas desulfurization device according to claim 1, characterized in that: The seawater tank is provided with two accommodation spaces, and the bottom of both accommodation spaces is distributed with the aeration membranes. The liquid level of the accommodation space on the side close to the inlet end of the seawater tank is higher than the liquid level of the accommodation space on the side close to the outlet end of the seawater tank, and the seawater in the high liquid level accommodation space can flow into the low liquid level accommodation space.

9. A desulfurization method using the ship exhaust gas desulfurization device described in claim 1, characterized in that: Including the following: (1) The sulfur-containing ship exhaust gas to be treated is sent into the sulfur-containing ship exhaust gas pretreatment system, dust and oil are removed, and the pressure is increased to 20 - 80 kPa, and then it is sent into the shell side of the membrane contactor; (2) Seawater is sent into the seawater pretreatment system, pressurized to 30 - 120 kPa after sand filtration and microfiltration, and then sent into the tube side of the membrane contactor; (3) The exhaust gas flowing in the shell side of the membrane contactor and the seawater flowing in the tube side of the membrane contactor perform gas-liquid mass transfer, sulfur dioxide in the exhaust gas is absorbed by the seawater, and the liquid phase pressure on the seawater side is kept 10 - 40 kPa higher than the gas phase pressure on the exhaust gas side; the treated exhaust gas is discharged from the outlet end of the shell side of the membrane contactor, and the seawater after absorbing sulfur dioxide is discharged from the outlet end of the tube side of the membrane contactor and enters the seawater post-treatment system; (4) The seawater that has absorbed sulfur dioxide enters the seawater tank of the seawater post-treatment system. Aeration membranes are distributed in the seawater tank, air with a pressure of 20 - 80 kPa is introduced into the aeration membranes, and a large number of fine bubbles are generated in the seawater tank to oxidize sulfite into sulfate.

Images