A desulfurization tower and desulfurization method based on enhanced absorption by flat-plate membrane internals

Abstract

This invention discloses a desulfurization tower and method based on enhanced absorption using a flat-plate membrane internal. The desulfurization tower includes a tower body, and from top to bottom, a liquid distributor, a flat-plate membrane internal, and a fractal internal. This invention utilizes the high turbulence characteristics of the fractal internal to rapidly pre-desulfurize high-concentration sulfur-containing gas at the bottom of the tower, instantly reducing sulfide concentration and optimizing gas flow distribution. The pre-desulfurized gas then enters a high-efficiency fine desulfurization zone composed of the flat-plate membrane internal. This flat-plate membrane internal uses several vertically arranged plates to form a fixed gas flow channel, restricting the lateral movement of gas molecules and resulting in a more uniform gas distribution. Simultaneously, a uniform and continuous absorbent liquid film forms on the plate surface, significantly increasing the gas-liquid contact area. Under extremely low pressure drop, through sufficient countercurrent contact between the gas and the absorbent liquid film and efficient gas-liquid mass transfer, it achieves both high efficiency and low energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of gas purification technology, specifically relating to a desulfurization tower and desulfurization method based on enhanced absorption by flat-panel membrane internals. Background Technology

[0002] In industrial gas purification, desulfurization is a crucial step to ensure the smooth operation of subsequent processes (such as combustion), prevent equipment corrosion, and avoid environmental pollution. The key equipment in this process is the desulfurization tower. Traditional desulfurization towers mostly employ packed towers or plate tower structures, which have the following shortcomings:

[0003] Uneven distribution of the absorbent can easily lead to excessively thick or broken liquid films, or the absence of liquid films in some areas. This results in low gas-liquid contact efficiency, small gas-liquid contact area, short contact time, and incomplete reaction, ultimately limiting desulfurization efficiency. The internal structure has weak control over gas-liquid flow, making it easy for the gas and liquid phases to deviate. Insufficient mass transfer enhancement and high mass transfer resistance make it difficult to meet increasingly stringent environmental protection requirements and industrial development needs.

[0004] Existing technologies have already provided some solutions to the above problems:

[0005] CN223042470U discloses a high-efficiency turbulent flow desulfurization tower, whose internal structure consists of a secondary turbulent flow layer and other components. The first layer is a first turbulent flow layer, which uses an orifice plate gas distribution device to achieve turbulence; the second layer is a liquid distribution layer, which is composed of a novel multi-stage disc liquid distributor and a novel packing layer.

[0006] This tower employs a novel multi-stage gas turbulence structure. Gas enters the tower from bottom to top, first passing through a perforated plate to form the first turbulence layer. It then ascends into the gas-liquid contact zone, which consists of a disc-type liquid distribution device and a liquid distribution layer. Above the contact zone, a tube-bundle demister layer serves as the secondary turbulence layer. Finally, a rod-type tertiary turbulence layer is added. This multi-stage turbulence treatment results in a more compact tower structure and more thorough gas-liquid contact, thereby improving desulfurization efficiency and reducing desulfurization costs.

[0007] However, this scheme still has the following drawbacks: First, the over-reliance on turbulence and packing to enhance mass transfer inevitably leads to a significant increase in system pressure drop, thereby increasing energy consumption and operating costs. Second, although a multi-stage distribution is adopted, the uniform distribution of the gas and liquid phases is not fundamentally solved in the complex turbulence and packing regions, which easily leads to phenomena such as flow deviation and channeling, resulting in some packing surfaces not being effectively wetted, thus limiting the improvement of mass transfer efficiency. Summary of the Invention

[0008] To overcome the problems of low mass transfer efficiency, large pressure drop, and uneven gas-liquid distribution in existing desulfurization towers, this invention provides a desulfurization tower and desulfurization method based on enhanced absorption by flat plate membrane internals. In this desulfurization tower, deep desulfurization is achieved through the synergistic effect of fractal internals and flat plate membrane internals, achieving a "coarse first, then fine" process.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] The first aspect of the present invention is to provide a desulfurization tower based on enhanced absorption of a flat membrane internal, comprising a desulfurization tower body, a liquid distributor, a flat membrane internal, and a fractal internal arranged sequentially from top to bottom within the desulfurization tower body, wherein the desulfurization tower body is provided with a first liquid inlet communicating with the fractal internal and a second liquid inlet communicating with the liquid distributor, and an air inlet is provided at the lower part of the desulfurization tower body, and an air outlet and a liquid outlet are provided at the top and bottom of the desulfurization tower body, respectively.

[0011] The fractal internal component is a Venturi structure and is located below the air inlet. It is used to pretreat sulfur-containing gas and includes a converging channel, a throat channel, and a expanding channel. The converging channel is connected to the first liquid inlet through a pipe, and the throat channel is provided with several suction holes.

[0012] The liquid distributor is a gravity-type distributor;

[0013] The flat membrane internals are used for deep desulfurization and include several vertically arranged flat plates and an external frame for supporting and fixing the flat plates, with fixed gas flow channels formed between adjacent flat plates.

[0014] In some embodiments, the desulfurization tower is provided with 2-4 fractal internals; the throat channel of the fractal internals is provided with 1-3 air intake holes; the diameter of the throat channel is 3 mm-6 mm; the contraction angle is 25°-35°, and the expansion angle is 15°-25°.

[0015] The fractal internals are made of high-strength, corrosion-resistant materials, including stainless steel 304, 316L, and duplex stainless steel.

[0016] In some embodiments, the length of the tapering channel accounts for 40%-45% of the total length of the fractal internals, the length of the throat channel accounts for 8%-10% of the total length of the fractal internals, and the length of the expanding channel accounts for 45%-52% of the total length of the fractal internals; the total length of the fractal internals is 15cm-65cm.

[0017] In some embodiments, the flat membrane inner element is made of a hydrophilic and corrosion-resistant material; the material includes stainless steel 304, stainless steel 316L, duplex stainless steel, polypropylene, polyvinyl chloride, and alumina ceramic.

[0018] In some embodiments, the surface of the plate is provided with a corrugated structure to guide the absorbent to flow uniformly on the surface of the plate.

[0019] In some embodiments, the overall diameter of the flat plate membrane internal is slightly smaller than the diameter of the desulfurization tower, and its overall height accounts for 1 / 3 to 5 / 12 of the height of the desulfurization tower. The ratio of the height of the outer frame to the height of the flat plate is 1 / 3 to 1, and the space occupied by the flat plate membrane internal is 1 / 3 to 1 / 2 of the volume of this section of the empty tower. The thickness of a single plate is 1 / 125 to 1 / 100 of the inner diameter of the desulfurization tower body, and the ratio of the thickness of a single plate to the distance between two adjacent plates is 1 / 2 to 1.

[0020] The distance between the fractal internals and the flat membrane internals is 1.5 to 3.0 times the diameter of the desulfurization tower.

[0021] In some embodiments, the liquid distributor includes a main pipe communicating with a second inlet and a titration plate communicating with the main pipe; the titration plate is provided with a plurality of openings or slots, the center position of which corresponds to the center line of the upper edge of the plate in the flat plate membrane inner part below it.

[0022] In some embodiments, the ratio of the aperture diameter to the thickness of a single plate is 0.8-1; the ratio of the width of the slot to the thickness of a single plate is 0.8-1.

[0023] In some embodiments, the desulfurization tower is provided with a liquid storage tank below the fractal internals. The liquid storage tank is connected to the liquid outlet and is connected to the first liquid inlet and the second liquid inlet through pipelines to realize the recycling of the absorbent.

[0024] A second aspect of the present invention is to provide a desulfurization method using the above-described desulfurization tower, comprising the following steps:

[0025] S1: The two absorbents are respectively delivered to the liquid distributor and the fractal internals, and the sulfur-containing gas enters the desulfurization tower through the inlet;

[0026] S2: At the bottom of the tower, as the absorbent flows through the fractal internals, its Venturi structure causes the liquid to flow at high speed in the throat channel, generating negative pressure, drawing in sulfur-containing gas, and spraying upwards a turbulent liquid column rich in bubbles; the liquid column comes into intense contact with the sulfur-containing gas that has just entered the tower. During this process, the formation and collapse of bubbles greatly increases the gas-liquid contact area and strongly disturbs the airflow, achieving preliminary desulfurization and uniform gas distribution;

[0027] S3: At the top of the tower, another stream of absorbent enters the flat plate membrane internals stably and evenly through the liquid distributor, forming a uniform and continuous absorbent liquid film on the surface of the flat plate by gravity.

[0028] S4: After being processed by the fractal internals, the sulfur-containing gas continues to flow upward and enters the gas flow channel between the plates from bottom to top. It makes full countercurrent contact with the absorbent liquid film flowing from top to bottom on the plate surface, thereby achieving deep desulfurization.

[0029] S5: The clean gas after desulfurization is discharged from the outlet, while the absorbent after the reaction continues to fall and merges with the absorbent sprayed by the fractal internals into the bottom of the tower, and then is discharged.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The desulfurization tower based on flat-plate membrane internals for enhanced absorption of the present invention adopts a two-stage desulfurization process of "fine desulfurization followed by coarse desulfurization". Fractal internals are installed in the lower part of the tower, which utilize their high turbulence characteristics to rapidly pre-desulfurize high-concentration sulfur-containing gases at the bottom of the tower. This not only instantly reduces the sulfide concentration, but also optimizes the airflow distribution, creating a more uniform airflow field for subsequent processes.

[0032] The pre-desulfurized gas then enters a high-efficiency fine desulfurization zone composed of a flat-plate membrane internal. This internal utilizes several vertically arranged plates to form fixed gas flow channels, restricting the lateral movement of gas molecules and resulting in a more uniform gas distribution. Simultaneously, a uniform and continuous absorbent liquid film forms on the plate surface, significantly increasing the gas-liquid contact area. Within this zone, due to the significantly reduced sulfide concentration and uniform gas distribution, deep desulfurization can be achieved under extremely low pressure drop through sufficient countercurrent contact between the gas and the absorbent liquid film and efficient gas-liquid mass transfer. This staged treatment strategy effectively resolves the contradiction between high efficiency and low energy consumption that traditional desulfurization devices struggle to achieve simultaneously. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a desulfurization tower structure based on enhanced absorption using flat-plate membrane internals, according to a specific embodiment.

[0034] Figure 2 This is a schematic diagram of the fractal internals.

[0035] Figure 3a and Figure 3b These are the front view and top view of the flat membrane internals, respectively.

[0036] Figure 4a and Figure 4b These are schematic diagrams of the structure of a titration plate with openings and grooves.

[0037] In the picture:

[0038] 10-Desulfurization tower body; 11-First liquid inlet; 12-Second liquid inlet; 13-Air inlet; 14-Air outlet; 15-Liquid outlet;

[0039] 20-Liquid distributor; 21-Titting plate; 22-Opening; 23-Slotted;

[0040] 30 - Sheet membrane inner components; 31 - Sheet membrane; 32 - External frame;

[0041] 40 - Fractal internal component; 41 - Tapered channel; 42 - Throat channel; 43 - Expanding channel; 44 - Intake port;

[0042] 50-Reservoir. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0044] For example, Figure 1 A schematic diagram of a desulfurization tower based on flat-plate membrane internals for enhanced absorption is shown in a specific embodiment. (Refer to...) Figure 1 The desulfurization tower includes a desulfurization tower body 10, a liquid distributor 20, a flat membrane inner component 30, and several fractal inner components 40 arranged sequentially from top to bottom inside the desulfurization tower body 10. The desulfurization tower body 10 is provided with a first liquid inlet 11 communicating with the fractal inner components 40 and a second liquid inlet 12 communicating with the liquid distributor 20. The lower part of the desulfurization tower body 10 is provided with an air inlet 13, and the top and bottom are respectively provided with an air outlet 14 and a liquid outlet 15.

[0045] Combination Figure 2 As shown, the fractal internal component 40 has a venturi structure and is located below the air inlet 13. It is used to pretreat sulfur-containing gas and includes a converging channel 41, a throat channel 42, and a expanding channel 43. The converging channel 41 is connected to the first liquid inlet 11 through a pipe, and the throat channel 42 is provided with several suction holes 44.

[0046] A portion of the absorbent enters the tower through the first inlet 11 and, as it flows through the fractal internal component 40, creates a negative pressure at its throat channel 42. This draws in sulfur-containing gas through the suction port 44 and sprays upwards a liquid column containing bubbles, resulting in a more uniform distribution of the absorbent and a larger liquid film absorption area in the desulfurization tower. Furthermore, the coalescence and collapse of the bubbles further increase the liquid film absorption area and disturb the airflow, creating a more uniform airflow field, thereby improving mass transfer efficiency and the initial desulfurization effect.

[0047] Another portion of the absorbent enters the liquid distributor 20 from the second inlet 12, and after being evenly distributed, enters the flat membrane inner part 30; the liquid distributor 20 is a gravity distributor.

[0048] Combination Figure 3a and Figure 3b As shown, the flat plate membrane internal 30 is used for deep desulfurization and includes several vertically arranged flat plates 31 and an external frame 32 for supporting and fixing the flat plates 31. A fixed gas flow channel is formed between adjacent flat plates 31 to restrict the lateral movement of gas.

[0049] The absorbent from the liquid distributor 20 forms a liquid film on the surface of the plate 31. The sulfur-containing gas enters the gas flow channel of the plate membrane internals 30 from bottom to top and comes into counter-current contact with the absorbent liquid film, making the gas-liquid distribution more uniform and greatly enhancing the gas-liquid mass transfer efficiency, thereby further improving the desulfurization efficiency.

[0050] The aforementioned desulfurization tower first utilizes the high turbulence characteristics of the fractal internals 40 to efficiently pre-desulfurize high-concentration sulfur-containing gas at the bottom of the tower. This process instantly reduces the sulfide concentration in the gas and creates a more uniform airflow field for subsequent processes. Subsequently, the gas enters the high-efficiency fine desulfurization zone composed of the flat-plate membrane internals 30. Because the sulfide concentration has been significantly reduced and the gas distribution is uniform, deep desulfurization can be completed under extremely low pressure drop through sufficient countercurrent contact between the gas and the absorbent liquid film and efficient gas-liquid mass transfer. This "coarse-to-fine" design overcomes the contradiction that a single component cannot simultaneously achieve high efficiency and low energy consumption.

[0051] In some embodiments, 2-4 fractal internals 40 are provided inside the desulfurization tower. The throat channel 42 of the fractal internal is provided with 1-3 air intake holes. The diameter of the throat channel 42 is 3 mm-6 mm, the contraction angle is 25°-35°, and the expansion angle is 15°-25°.

[0052] The total length of the fractal inner part 40 can be adjusted within the range of 15cm-65cm according to the actual working conditions. Among them, the length of the tapered channel 41 accounts for 40%-45% of the total length of the fractal inner part 40, the length of the throat channel 42 accounts for 8%-10% of the total length of the fractal inner part 40, and the remaining part of the fractal inner part 40 is the expanding channel 43, the length of which is determined according to the actual ratio of the throat channel 42 and the tapered channel 41, and is approximately 45%-52% of the total length of the fractal inner part 40.

[0053] The fractal inner component 40 is preferably made of a high-strength, corrosion-resistant material, such as 304 stainless steel, 316L stainless steel, or duplex stainless steel. The fractal inner component 40 is detachably fixed to the pipe, for example, by means of a threaded connection, to ensure installation stability.

[0054] In some embodiments, the flat membrane inner element 30 is made of a hydrophilic and corrosion-resistant material. Using a hydrophilic material can further increase the gas-liquid contact area and prolong the contact time, thereby enhancing the mass transfer effect. The material can be selected from stainless steel materials such as 304 stainless steel, 316L stainless steel, and duplex stainless steel, or materials such as polypropylene (PP), polyvinyl chloride (PVC), and alumina ceramics.

[0055] In some preferred embodiments, to promote the formation of a uniform liquid film on the surface of the plate 31, a corrugated structure can be provided on the surface of the plate 31 to guide the absorbent to flow uniformly on the surface of the plate 31, forming a continuous and stable liquid film and ensuring full contact between the absorbent and the gas.

[0056] In some embodiments, the flat sheet membrane inner component 30 is detachably assembled. The outer frame 32 is provided with a slot (not shown in the figure) adapted to the size of the flat sheet 31. The flat sheet 31 is inserted into the slot of the outer frame 32 for fixation. The flat sheet membrane inner component 30 can be detachably fixed to the inner wall of the desulfurization tower through the outer frame 32. For example, the outer frame 32 and the tower body are connected by a flange to achieve quick assembly and disassembly of the whole, or a baffle is installed on the inner wall of the desulfurization tower to place the flat sheet membrane inner component 30.

[0057] In some embodiments, the overall diameter of the flat plate membrane inner component 30 is slightly smaller than the inner diameter of the desulfurization tower to facilitate installation. The overall height of the flat plate membrane inner component 30 accounts for 1 / 3 to 5 / 12 of the height of the desulfurization tower. The ratio of the height of the outer frame 32 to the height of the flat plate 31 is 1 / 3 to 1. The space occupied by the flat plate membrane inner component 30 is approximately 1 / 3 to 1 / 2 of the volume of this section of the empty tower. The thickness of a single flat plate 31 is 1 / 125 to 1 / 100 of the inner diameter of the desulfurization tower body 10.

[0058] Considering that desulfurization reactions (such as H2S absorption) are typically controlled by gas-film mass transfer and have extremely fast reaction rates, maximizing the gas-liquid contact area per unit volume is key to improving efficiency. Simultaneously, to ensure the stability of the liquid film and the unobstructed gas flow channels, the ratio of the thickness of a single plate 31 to the distance between two adjacent plates 31 (i.e., the plate spacing) is 1 / 2 to 1. This matching relationship ensures that while achieving a high specific surface area, excessively high system pressure drop is avoided.

[0059] The distance between the fractal internal component 40 and the flat plate membrane internal component 30 needs to be adjusted according to the actual operating conditions. If the distance is too close, the liquid column generated by the fractal internal component 40 will impact the liquid film formed on the surface of the flat plate 31; if the distance is too far, the disturbance effect generated by the fractal internal component 40 will be weakened, and it will not be able to provide ideal inlet conditions for the flat plate membrane region. Therefore, the distance between the fractal internal component 40 and the flat plate membrane internal component 30 is 1.5 to 3.0 times the diameter of the desulfurization tower.

[0060] In some preferred embodiments, such as Figure 4a and Figure 4b As shown, the liquid distributor 20 includes a main pipe communicating with the second liquid inlet 12 and a titration plate 21 communicating with the main pipe. The titration plate 21 is provided with a plurality of openings 22 or slots 23.

[0061] The material of the titration plate 21 in the liquid distributor 20 is compatible with the absorbent. For example, PVC or FRP is used when treating acidic absorbents, and stainless steel 316L is used when treating high-temperature absorbents (≥80℃).

[0062] When designing the titration plate 21, the aperture (or width) and spacing of the openings 22 (or slots 23) in the titration plate 21 are set according to the thickness of the plate 31 and the plate spacing parameters in the flat plate membrane inner component 30. To ensure accurate liquid guidance and allow for installation tolerances, the aperture or the width of the slot 23 should be slightly less than or equal to the thickness of the plate 31. Preferably, the ratio of the aperture of the opening 22 to the thickness of a single plate 31 is 0.8-1; the ratio of the width of the slot 23 to the thickness of a single plate 31 is 0.8-1; the center position of the opening 22 or the slot 23 corresponds to the center line of the upper edge of the plate 31 in the flat plate membrane inner component 30 below it. The purpose is to ensure that each liquid flow can drip accurately and stably onto the center line of the upper edge of the corresponding plate 31, and then overflow evenly on both sides of the plate 31, forming a liquid film of uniform thickness on both sides of the plate 31 under the action of gravity.

[0063] The fixed design parameters of the flat sheet membrane internals 30, such as sheet thickness, sheet spacing, as well as the hydrophilicity and surface texture of the material, together create a specific hydrodynamic environment. Based on this, operators can actively control the overflow state of the absorbent on the surface of the flat sheet 31 by adjusting the key variable of liquid flow rate, thereby forming a uniform and continuous liquid film with controllable thickness.

[0064] In high-volume load conditions or when the gas to be treated contains solid particles such as dust and fly ash, posing risks of absorbent foaming and scaling, a larger plate spacing and wider flow channels are typically used to effectively prevent clogging and extend the operating cycle. In this case, to ensure sufficient gas-liquid contact time and mass transfer effect, the liquid flow rate can be increased to form a thicker liquid film on the surface of plate 31.

[0065] In some preferred embodiments, such as Figure 1 As shown, the desulfurization tower of the present invention has a liquid storage tank 50 below the fractal internal component 40. The liquid storage tank 50 is connected to the liquid outlet 15 and is connected to the first liquid inlet 11 and the second liquid inlet 12 through pipelines to realize the recycling of the absorbent.

[0066] The desulfurization method using the above-mentioned desulfurization tower based on enhanced absorption by flat-plate membrane internals includes the following steps:

[0067] S1: The fresh absorbent or the absorbent in the storage tank 50 is divided into two streams and transported to the liquid distributor 20 and the fractal internal component 40. The sulfur-containing gas enters the desulfurization tower through the air inlet 13.

[0068] S2: At the bottom of the tower, when the absorbent flows through the fractal internals 40, due to its Venturi structure, the liquid flows at high speed in the throat channel 42, generating negative pressure. It draws in sulfur-containing gas through the suction hole 44 and sprays upward a turbulent liquid column rich in bubbles. These liquid columns come into intense contact with the sulfur-containing gas that has just entered the tower. During this process, the formation and collapse of bubbles greatly increases the gas-liquid contact area and strongly disturbs the airflow, achieving preliminary desulfurization and uniform gas distribution.

[0069] S3: At the top of the tower, another stream of absorbent flows steadily and evenly to the surface of the flat membrane inner part 30 via the liquid distributor 20, forming a uniform and continuous liquid film by gravity.

[0070] S4: After being pretreated by the fractal internals 40, the sulfur-containing gas continues to flow upward and enters the gas flow channel formed by the flat plate membrane internals 30 from bottom to top. It makes full countercurrent contact with the absorbent liquid film flowing from top to bottom on the surface of the flat plate 31, thereby achieving deep desulfurization.

[0071] S5: The clean gas after desulfurization is discharged from the outlet 14, and the absorbent after the reaction continues to fall and flows into the storage tank 50 at the bottom of the tower together with the absorbent sprayed by the fractal internals 40. The absorbent in the storage tank 50 is sent back to the tower for recycling by the circulation pump, or discharged through the outlet 15 and sent to the regeneration unit for treatment. Fresh absorbent can be replenished through the inlet pipeline of the circulation pump.

[0072] In some embodiments, the temperature of the sulfur-containing gas entering the desulfurization tower should be maintained at 30°C-40°C.

[0073] In some embodiments, the absorbent is a 28wt%-32wt% aqueous solution of methyl diethanolamine (MDEA) or a mixed aqueous solution of MDEA and monoethanolamine (MEA).

[0074] Example 1

[0075] The desulfurization effect of the above-mentioned desulfurization tower based on flat membrane internal enhanced absorption was compared with that of the traditional packed tower.

[0076] 1. Desulfurization tower parameter settings

[0077] In this embodiment of the invention, the desulfurization tower has an inner diameter of 800 mm and a total effective height of 6 m; wherein:

[0078] The inner component 30 of the flat membrane is made of 316L stainless steel. The overall height is 2 m. It consists of flat plates 31 with a thickness of 7 mm and a spacing of 10 mm. The height of the outer frame is 1.8 m.

[0079] Three fractal internal components 40 are symmetrically installed at the bottom of the tower. The material of the internal component is 316L stainless steel. The length of the fractal internal component 40 is 40cm. The length of the tapering channel 41 is 170mm. The length of the expanding channel 43 is 194mm. The length of the throat channel 42 is 36mm. Its diameter is 5mm. It is equipped with three air intake holes 44. The tapering angle is 30° and the expanding angle is 20°.

[0080] The distance between the fractal inner element 40 and the flat membrane inner element 30 is 1.6m.

[0081] The liquid distributor 20 uses a slotted titration plate that precisely corresponds to the plate 31. The slot width is 7mm and the material is 316L stainless steel.

[0082] The packed tower has an inner diameter of 800 mm and a total effective height of 6 m; the packing uses DN25 stainless steel Pall rings, and the packing layer stack height is 3 m.

[0083] 2. Specific process parameter settings

[0084] The specific parameters of the sulfur-containing gas to be treated are: gas flow rate 3000 Nm³ / h, inlet gas H2S concentration 5000 ppm, and operating temperature 35 ℃.

[0085] The specific parameters of the absorbent used are: 30wt% methyldiethanolamine (MDEA) aqueous solution, with a liquid circulation rate of 8 m³ / h.

[0086] 3. Performance Comparison

[0087] Desulfurization efficiency analysis: After the process in this embodiment, the H2S concentration at the gas outlet is consistently below 10 ppm, with a desulfurization efficiency as high as 99.8%; while in comparison, the H2S concentration at the gas outlet of the packed tower is approximately 150 ppm, with a desulfurization efficiency of approximately 97.0%. Its performance is about 2.8 percentage points better than that of the traditional packed tower, and it can meet increasingly stringent environmental emission standards.

[0088] Pressure drop analysis within the tower: The total pressure drop of the system in this embodiment is less than or equal to 1.5 kPa, while the total pressure drop of the packed tower system is about 3.2 kPa, a reduction of more than 50%. This directly corresponds to lower operating energy consumption and has significant economic benefits.

[0089] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A desulfurization tower based on flat membrane internals enhanced absorption, characterized in that, The desulfurization tower comprises a desulfurization tower body, a liquid distributor, a flat plate membrane inner part and a plurality of fractal inner parts which are sequentially arranged in the desulfurization tower body from top to bottom, the desulfurization tower body is provided with a first liquid inlet communicated with the fractal inner parts and a second liquid inlet communicated with the liquid distributor, the lower part of the desulfurization tower body is provided with an air inlet, and the top and bottom of the desulfurization tower body are respectively provided with an air outlet and a liquid outlet; The fractal inner part is in a Venturi structure and is located below the air inlet and is used for pre-treating the sulfur-containing gas, and comprises a converging channel, a throat channel and a diverging channel, the converging channel is communicated with the first liquid inlet through a pipeline, and a plurality of air suction holes are arranged on the throat channel. The liquid distributor is a gravity type distributor. The flat plate membrane inner part is used for deep desulfurization and comprises a plurality of vertically arranged flat plates and an external frame for supporting and fixing the flat plates, and fixed gas flow channels are formed between adjacent flat plates.

2. The desulphurization tower based on flat sheet membrane internals enhanced absorption according to claim 1, characterized in that, 2-4 fractal inner parts are arranged in the desulfurization tower, 1-3 air suction holes are arranged on the throat channel of the fractal inner part, the diameter of the throat channel is 3 mm-6 mm, the converging angle is 25°-35°, and the diverging angle is 15°-25°. The fractal inner part is made of high-strength corrosion-resistant material, and the material comprises stainless steel 304, stainless steel 316L and duplex stainless steel.

3. The desulfurization tower based on flat sheet membrane internals enhanced absorption according to claim 2, characterized in that, The length of the converging channel accounts for 40%-45% of the total length of the fractal inner part, the length of the throat channel accounts for 8%-10% of the total length of the fractal inner part, and the length of the diverging channel accounts for 45%-52% of the total length of the fractal inner part.

4. The desulfurization tower based on flat sheet membrane internals enhanced absorption according to claim 1, characterized in that, The flat plate membrane inner part is made of hydrophilic and corrosion-resistant material, and the material comprises stainless steel 304, stainless steel 316L, duplex stainless steel, polypropylene, polyvinyl chloride and alumina ceramic.

5. The desulfurization tower based on flat sheet membrane internals enhanced absorption according to claim 1, characterized in that, The surface of the flat plate is provided with a corrugated structure to guide the uniform flow of the absorbent on the surface of the flat plate.

6. The desulfurization tower based on flat sheet membrane internals enhanced absorption according to claim 1, characterized in that, The overall diameter of the flat plate membrane inner part is slightly smaller than the inner diameter of the desulfurization tower, the overall height of the flat plate membrane inner part accounts for 1 / 3-5 / 12 of the height of the desulfurization tower, the height ratio of the external frame to the flat plate is 1 / 3-1, the space occupied by the flat plate membrane inner part accounts for 1 / 3-1 / 2 of the empty tower volume in this section, the thickness of a single flat plate is 1 / 125 to 1 / 100 of the inner diameter of the desulfurization tower body, and the thickness ratio of a single flat plate to the spacing between adjacent two flat plates is 1 / 2 to 1. The distance between the fractal inner part and the flat plate membrane inner part is 1.5 times to 3.0 times of the diameter of the desulfurization tower.

7. The desulphurization tower based on flat sheet membrane internals enhanced absorption according to claim 6, characterized in that, The liquid distributor comprises a main pipe communicated with the second liquid inlet and a titration plate communicated with the main pipe, a plurality of holes or grooves are arranged on the titration plate, and the center position of the holes or grooves corresponds to the upper edge center line of the flat plate in the flat plate membrane inner part below.

8. The desulphurization tower based on flat sheet membrane internals enhanced absorption according to claim 7, characterized in that, The ratio of the hole diameter of the hole to the thickness of a single flat plate is 0.8-1, and the ratio of the width of the groove to the thickness of a single flat plate is 0.8-1.

9. The desulphurization tower based on flat sheet membrane internals enhanced absorption according to claim 1, characterized in that, The desulfurization tower is provided with a liquid storage pool below the fractal inner part, the liquid storage pool is communicated with the liquid outlet and is communicated with the first liquid inlet and the second liquid inlet through pipelines, so that the absorbent can be recycled.

10. A desulfurization method using the desulfurization tower based on the flat sheet membrane internals enhanced absorption according to any one of claims 1 to 9, characterized by, The method comprises the following steps: S1: Two routes of absorption liquid are transported to liquid distributor and fractal internals respectively, and sulfur-containing gas enters the tower through the gas inlet; S2: In the lower part of the tower, one route of absorption liquid flows through fractal internals, and due to the Venturi structure, the liquid flows at high speed in the throat passage to generate negative pressure, thereby absorbing sulfur-containing gas and ejecting a turbulent liquid column rich in bubbles upward; the liquid column is in violent contact with the sulfur-containing gas just entering the tower, and in this process, the formation and rupture of bubbles greatly increase the gas-liquid contact area and strongly disturb the gas flow, thereby achieving preliminary desulfurization and gas distribution; S3: In the upper part of the tower, the other route of absorption liquid enters the flat membrane internals through the liquid distributor stably and uniformly, and a uniform and continuous absorption liquid film is formed on the flat surface by gravity; S4: The sulfur-containing gas treated by fractal internals continues to flow upward and enters the gas flow passage between the flat plates from bottom to top, and fully counter-currently contacts with the absorption liquid film flowing from top to bottom on the flat surface, thereby achieving deep desulfurization; S5: The clean gas after desulfurization is discharged from the gas outlet, and the reacted absorption liquid continues to fall and is collected with the absorption liquid ejected by fractal internals into the tower bottom, and then is discharged.

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