Environment-friendly multi-effect automatic force acid gas purification and recovery device and use method thereof

Abstract

The present application relates to the technical field of gas purification, in particular to an environment-friendly multi-effect automatic force acid gas purification and recovery device and a use method thereof. The device comprises a tower body, a plurality of gas purification sections are arranged in the tower body, a head is arranged between adjacent gas purification sections, a gas phase product outlet and a liquid phase raw material inlet are arranged at the top of the tower body, a liquid phase product outlet and a gas phase raw material inlet are arranged at the bottom of the tower body, and a cooler is arranged at the gas phase product outlet of the tower body; a gas phase rising pipe and a liquid phase descending pipe are arranged between adjacent gas purification sections; a gas distributor, a heating element and a catalyst layer are sequentially arranged in the gas purification section from bottom to top, the environment-friendly multi-effect automatic force acid gas purification and recovery device is integrated as a whole, the product is purified gas and a sodium salt solution, and there is no waste water and waste solid.

Description

Technical Field

[0001] This invention relates to the field of gas purification technology, specifically to an environmentally friendly multi-effect automatic acid gas purification and recovery device and its usage method. Background Technology

[0002] H2S is commonly found in oil and gas fields rich in acidic gases, and it also exists prevalently as a byproduct in fossil fuel processing, such as oil refining and coal gasification. It is a flammable, highly toxic, and corrosive gas, and during combustion, it is oxidized into sulfur oxides (SOx), polluting the atmosphere and causing further harm to the ecological environment. Recovering and utilizing sulfur from acidic gases is not only economically valuable but also an inevitable measure given the increasingly stringent sulfur emission regulations in various countries.

[0003] Currently, acid gas treatment processes are mainly divided into two categories based on the final product: acid gas to produce sulfur and acid gas to produce chemical products (such as sulfuric acid, ammonium sulfite, sodium sulfite, sodium hydrosulfide, thiourea, etc.).

[0004] The Claus process is a mature technology, adaptable to feed gas with complex compositions or concentrations, and offers good treatment results, making it the mainstream process for treating acidic gases in domestic refining and chemical enterprises. However, this process requires a large investment, making it technically and economically unviable for small-scale refining and chemical enterprises.

[0005] Catalytic oxidation wet desulfurization, represented by the LO-CAT process, has a simple process flow and low initial investment cost, but high operating costs and low quality of the sulfur product produced.

[0006] Dry acid production technology is particularly suitable for treating acidic gases with high concentrations of H2S. The process is mature and reliable, and its production scale is unlimited. However, it also has some obvious disadvantages, such as poor adaptability to the composition of acidic gas feedstocks; relatively low technical and economic efficiency, such as long process flow and relatively high energy consumption; and the plant occupies a large amount of industrial land. In terms of environmental protection, a small amount of acidic wastewater needs to be treated.

[0007] The acid gas wet process for sulfuric acid production has a wide range of applications. It can directly process acidic gases to produce sulfuric acid products. It has strong adaptability to raw materials and is not very sensitive to changes in gas composition and load. Even if the moisture concentration in the gas is high (φ>30%), the mass fraction of the finished sulfuric acid can still reach 93%.

[0008] The production of sodium sulfite using acidic gas results in severe equipment corrosion, and the product quality is greatly affected by the composition of the flue gas, leading to a small market demand for the product.

[0009] The production of thiourea using acidic gas requires less investment in equipment, produces relatively good product quality, and enjoys a good market. However, traditional processes result in severe secondary pollution, high environmental costs, and even difficulty in passing environmental impact assessments. Furthermore, the calcium cyanamide required for production (or can be produced in-house from limestone, but this involves multiple steps and high energy consumption) must be purchased externally. A new one-step process is still under development.

[0010] The production of sodium hydrosulfide from acidic gas is a relatively simple process, insensitive to changes in gas composition, and offers high operational flexibility. It is suitable for acidic gas treatment in small refineries, and features low investment, quick results, and no secondary pollution. Compared to other processes, the production of sodium hydrosulfide from acidic gas has a shorter process flow, lower investment, and lower production costs, making it a technically and economically sound method. Furthermore, this process requires less industrial land, is environmentally friendly, and generates no waste residue or wastewater.

[0011] In summary, although the production of sodium hydrosulfide from acidic gas has advantages such as simple process, environmental friendliness, low investment and production costs, and small footprint, the commonly used sodium hydrosulfide production equipment currently suffers from low equipment integration, resulting in relatively cumbersome operation. Summary of the Invention

[0012] The purpose of this invention is to address the shortcomings of existing technologies by providing an environmentally friendly, multi-effect, automatic acid gas purification and recovery device and its usage method. This overcomes the problem of poor integration in existing devices for producing sodium hydrosulfide from acid gas, and its operation is simple.

[0013] This invention discloses an environmentally friendly, multi-effect, automatic acid gas purification and recovery device, comprising a tower body. Multiple gas purification sections for holding alkaline solutions are sequentially arranged along the length of the tower body. End caps are provided between adjacent gas purification sections. The top of the tower body has a gas phase product outlet and a liquid phase raw material inlet, while the bottom has a liquid phase product outlet and a gas phase raw material inlet. The gas phase product outlet and liquid phase raw material inlet are connected to the uppermost gas purification section, and the liquid phase product outlet and gas phase raw material inlet are connected to the lowermost gas purification section. A cooler is provided at the gas phase product outlet. Within each gas purification section, a gas distributor, a heating element, and a catalyst layer are sequentially arranged from bottom to top. Gas phase rising pipes and liquid phase descending pipes are connected through adjacent gas purification sections. The liquid phase descending pipes allow liquid to overflow from the uppermost gas purification section downwards in stages, and the gas purification sections allow gas to rise from the lowermost gas purification section upwards in stages.

[0014] With the above scheme, the gas enters from the gaseous feed inlet on the side of the device, passes through multiple gas purification sections, and exits from the gaseous product outlet at the top after passing through a cooler. The liquid condensed by the cooler flows back to the gas purification section by gravity, and the cooled purified gas can directly enter the gas pipeline network. Condensation and liquid separation are completed during the gas purification process, and there are no valve operations in the liquid separation and condensation systems, requiring no manual or control operations. The two systems are integrated together by welding, resulting in a simple process. The mass transfer driving force of the gas in the device is the inlet gas pressure, and the gas distributor of each reactor extends into the alkaline solution, utilizing the alkaline solution for liquid sealing. This eliminates the need for valve operations between the two reactor stages, effectively simplifying the process and reducing operations.

[0015] Liquid enters from the liquid-phase feed inlet on the side of the unit, filling the uppermost gas purification section. It then overflows from the internal liquid-phase downcomer to other gas purification sections. Once the designated liquid levels are reached in these sections, the valve at the liquid-phase feed inlet is closed, stopping the alkali injection and achieving online alkali injection. No operation of the unit is required during the entire injection process. After the lower section's alkali solution becomes saturated, the valve at the liquid-phase product outlet is opened, allowing the sodium hydrosulfide solution to drain from the bottom liquid-phase product outlet and flow by gravity to the sodium hydrosulfide product tank area. When the liquid level in the lowermost gas purification section reaches a low level alarm, the valve at the liquid-phase product outlet is closed, stopping the discharge. The alkali injection process only requires operating one alkali injection shut-off valve at the liquid-phase feed inlet, and the sodium hydrosulfide product discharge only requires operating one outlet shut-off valve at the liquid-phase product outlet, greatly simplifying the process and operation. In summary, the environmentally friendly multi-effect automatic acid gas purification and recovery device combines reaction and separation equipment, effectively integrating them into a single, highly efficient device. It optimizes and integrates existing pipelines and significantly simplifies operation procedures.

[0016] Preferably, a demister is installed between the gas purification section and the gas phase product outlet in the tower body.

[0017] Preferably, the demister is any one of a wire mesh demister, a baffle demister, or a cyclone demister.

[0018] Preferably, the gas distributor is a porous distributed type.

[0019] Preferably, the opening diameter of the gas distributor is 5-20 mm.

[0020] Preferably, the catalyst layer is a noble metal catalyst layer supported by a network structure.

[0021] Although the absorption of hydrogen sulfide by alkaline solution is an acid-base neutralization reaction, the gas is generated in the form of bubbles in the alkaline solution. A transition film exists at the gas-liquid interface, which significantly affects gas-liquid mass transfer, resulting in less than ideal washing effects for acidic gases under normal circumstances. Therefore, this device incorporates polymeric materials loaded with precious metals in each gas purification section to improve the absorption efficiency at the gas-liquid interface.

[0022] Preferably, each of the gas purification sections is equipped with a sampling port, which is used to analyze the degree of gas purification and the absorption saturation of the liquid in real time.

[0023] Through the above scheme, the degree of gas purification and the saturation of alkaline solution absorption can be analyzed in real time through the sampling port during the automatic absorption process. Different gas phase sampling analysis results can be compared and analyzed to ensure the gas purification effect can be monitored and compared at any time.

[0024] This invention also provides a method for using an environmentally friendly multi-effect automatic acid gas purification and recovery device. The aforementioned environmentally friendly multi-effect automatic acid gas purification and recovery device includes the following steps:

[0025] S1. Sodium hydroxide solution is injected through the liquid raw material inlet. After the liquid level in the uppermost gas purification section is higher than the top of the liquid downcomer, it automatically overflows to other gas purification sections through the liquid downcomer and reaches the specified liquid level. The temperature of each gas purification section is kept constant between 25 and 80°C by the heating element, and the cooler is turned on.

[0026] S2. Acidic gas is introduced through the gas phase raw material inlet and enters the sodium hydroxide solution. The gas riser passes through the sodium hydroxide solution in each gas purification section in sequence. The hydrogen sulfide in the gas is absorbed by the sodium hydroxide solution to generate sodium hydrosulfide. After being cooled by the cooler, the purified gas leaves the tower body through the gas phase product outlet and enters the fuel gas pipeline. The cooled condensate in the cooler flows back to the uppermost gas purification section by gravity.

[0027] Once the solution in the gas purification section is saturated, sodium hydrosulfide is discharged from the tower and flows to the product tank area through the liquid product outlet until the solution in the lowest gas purification section reaches the set low level. Then, the liquid product outlet is closed, and sodium hydroxide solution is injected through the liquid raw material inlet.

[0028] The beneficial effects of this invention are as follows: It achieves multi-stage series connection in gas alkaline washing and absorption, improving gas purification efficiency. Due to the high integration of equipment within the device and its small footprint, the workload of piping and equipment installation is reduced, greatly improving the construction efficiency of the device. Simultaneously, the reduced number of pipes and valves simplifies operation, increases production efficiency, and reduces the risk of misoperation and production accidents. Because of its low investment, small footprint, and short construction period, this device has excellent application potential in small-scale coal chemical and petrochemical enterprises, effectively solving environmental problems and bringing considerable economic benefits. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] In the diagram: 1. Tower body; 2. Gas purification section; 3. End cap; 4. Cooler; 5. Gas distributor; 6. Heating element; 7. Catalyst layer; 8. Demister; 9. Gas phase riser pipe; 10. Liquid phase fallr pipe. Detailed Implementation

[0031] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0032] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0033] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0036] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0037] The following table lists the port codes, names, and uses of an environmentally friendly, multi-effect, automatic acid gas purification and recovery device:

[0038] Table 1

[0039]

[0040]

[0041] Figure 1 This paper presents a schematic diagram of an environmentally friendly multi-effect automatic acid gas purification and recovery device according to a preferred embodiment of this application. For ease of explanation, only the parts relevant to this embodiment are shown. Figure 1 As shown in Table 1, an environmentally friendly multi-effect automatic acid gas purification and recovery device includes a tower body 1. Multiple gas purification sections 2 for placing alkaline solutions are sequentially arranged along the length of the tower body 1. Two or three gas purification sections 2 can be selected; in this embodiment, two gas purification sections 2 are provided. An end cap 3 is provided between adjacent gas purification sections 2 in the tower body 1. The end cap 3 is an elliptical end cap.

[0042] The top of tower body 1 is equipped with a gaseous product outlet N3 and a liquid raw material inlet N2, and the bottom is equipped with a liquid product outlet N4 and a gaseous raw material inlet N1. A valve is installed at the liquid product outlet N4. The gaseous product outlet N3 and the liquid raw material inlet N2 are connected to the uppermost gas purification section 2, and the liquid product outlet N4 and the gaseous raw material inlet N1 are connected to the lowermost gas purification section 2.

[0043] A cooler 4 is installed at the gas product outlet N3 of the tower body 1. The tower body 1 has a circulating cooling water inlet N12 and a circulating cooling water outlet N13 corresponding to the cooler 4. The cooler 4 is used to cool the purified gas and separate the condensed liquid through baffles. A demister 8 is installed between the gas purification section 2 and the gas product outlet N3 of the tower body 1. The demister 8 can be a wire mesh demister, a baffle demister, or a cyclone demister. In this embodiment, a wire mesh demister 8 is used.

[0044] The gas purification section 2 is arranged from bottom to top as follows: a gas distributor 5, a heating element 6, and a catalyst layer 7. The gas distributor 5 is a porous distributed system, which can be in the form of porous strips or rings, with an opening diameter of 5-20 mm. The purpose of the gas distributor 5 is to ensure that the gas rises evenly from the bottom. Since the intermediate product of the reaction is sodium sulfide, and the solubility of sodium sulfide at 20°C is 186 g / L, in order to ensure that the product quality of sodium hydrosulfide meets the L-2 product quality requirements of liquid sodium hydrosulfide in GB / T 23937-2009 "Industrial Sodium Hydrosulfide", the temperature needs to be increased during the reaction process; otherwise, the generated sodium sulfide crystals will block the pipes and valves. Therefore, the gas purification section 2 is equipped with heating elements 6, so that the entire reaction equipment and pipelines need to be insulated and heated to 65-80°C. In this embodiment, the heating element 6 is a circulating hot water pipe, and the tower body 1 has circulating hot water inlets N6 / N8 and circulating hot water outlets N5 / N7 corresponding to the circulating hot water pipe. Catalyst layer 7 is a noble metal catalyst layer supported by a network structure, which is beneficial to improving the absorption efficiency of the gas-liquid interface.

[0045] Each gas purification section 2 is equipped with a sampling port N10. The lowest gas purification section 2 has sampling ports N10 in both the gas and liquid phases, while the remaining gas purification sections 2 may only have sampling ports N10 in the gas phase. Sampling ports N10 are used for real-time analysis of the gas purification level and the liquid absorption saturation. Different gas phase sampling analyses can be compared to ensure continuous monitoring and comparison of the gas purification effect. Adjacent gas purification sections 2 are connected by gas phase riser pipes 9 and liquid phase fallr pipes 10. Gas rises from bottom to top through the gas phase riser pipes 9 for purification, while liquid flows downwards through the liquid phase fallr pipes 10 by gravity.

[0046] This application also discloses a method for using an environmentally friendly multi-effect automatic acid gas purification and recovery device. The method, employing the aforementioned environmentally friendly multi-effect automatic acid gas purification and recovery device, includes the following steps.

[0047] S1. Sodium hydroxide solution is injected through liquid raw material inlet N2. After the uppermost gas purification section 2 reaches a high liquid level, it automatically overflows to other gas purification sections 2 through liquid downcomer 10. The injection of alkali solution is stopped after each gas purification section 2 reaches a specified liquid level. The circulating hot water is connected through inlet N6 / N8. The temperature of each gas purification section 2 can be kept constant between 25 and 80°C through heating element 6, and the circulating cooling water pipeline of cooler 4 is turned on.

[0048] S2. Acidic gas is introduced through the gaseous raw material inlet N1 and enters the sodium hydroxide solution. It is pushed by pressure and passes through the sodium hydroxide solution of each gas purification section 2 in sequence along the gas rising pipe. The hydrogen sulfide in the gas is absorbed by the sodium hydroxide solution in multiple stages and generates sodium hydrosulfide. After the purified gas is cooled to 40°C by the cooler 4, it leaves the tower body 1 through the gaseous product outlet N3 and enters the fuel gas pipeline (in the purified gas). The condensate flows back to the uppermost gas purification section 2 along the baffle of the cooler 4.

[0049] Once the solution in the gas purification section 2 is saturated, the sodium hydrosulfide product can be discharged from tower 1 and flow to the product tank area by opening the valve at the liquid product outlet N4 until the solution in the lowest gas purification section 2 is at a low level. Then, the valve at the liquid product outlet N4 is closed, and sodium hydroxide solution is injected through the liquid raw material inlet N2.

[0050] Example 1

[0051] This embodiment provides an example of a method for using this device to treat acidic tail gas from a crude benzene hydrogenation unit. The components of the acidic tail gas generated by a crude benzene hydrogenation unit are shown in Table 2.

[0052] Table 2 Composition of Acidic Gases

[0053] Components Content (vol) <![CDATA[H2S]]> 1％ <![CDATA[NH3]]> 1.3％ <![CDATA[H2, non-condensable gas]]> 75～80％ <![CDATA[H2O(g)]]> 1.1％ <![CDATA[CH4]]> 2％ Light hydrocarbons

[0054] Step A: The NaOH solution injected into the environmentally friendly multi-effect automatic acid gas purification and recovery device will automatically overflow into the lower gas purification section 2 after the liquid level in the upper gas purification section 2 reaches a high level, until the lower gas purification section 2 reaches a designated liquid level. The circulating hot water is then connected to maintain the temperature of each gas purification section 2 at 25–80°C, and the circulating cooling water pipeline of the cooler 4 is simultaneously turned on.

[0055] Step B: Set the flow rate to 100 Nm 3Acidic gas with a gauge pressure of 0.4 MPa is introduced into the device. The acidic gas passes through gas distributor 5 and enters the alkaline solution, where H2S is absorbed to form sodium hydrosulfide. The pressure in the lower gas purification section 2 is 0.35 MPa, and the pressure in the upper gas purification section 2 is 0.3 MPa. Sampling and analysis using a sampler show that the H2S concentration in gas purification section 2 is ≤10 ppm. The purified gas exits the device and is connected to the fuel gas pipeline network.

[0056] Step C: During the operation of the device, each shift takes a sample of the solution in the lower gas purification section 2 for analysis. When the absorption is saturated, the valve at the liquid product outlet N4 is opened to allow the sodium hydrosulfide product to flow by gravity to the product tank area. When the solution in the lower gas purification section 2 flows by gravity to the low liquid level, the valve at the liquid product outlet N4 is closed, and then alkali solution is injected from the liquid raw material inlet N2 until the solution in the lower gas purification section 2 rises to the designated liquid level.

[0057] Example 2

[0058] This embodiment provides an example of a method for using this device to treat acidic tail gas from a waste lubricating oil hydrogenation unit. The components of the acidic tail gas generated by a crude benzene hydrogenation unit are shown in Table 3.

[0059] Table 3 Composition of Acidic Gases

[0060] Components Content (vol) <![CDATA[H2S]]> 14.2％ <![CDATA[NH3]]> 1.3％ <![CDATA[H2, non-condensable gas]]> 83.3％ <![CDATA[H2O(g)]]> 1.1％

[0061] Step A: The NaOH solution injected into the environmentally friendly multi-effect automatic acid gas purification and recovery device will automatically overflow into the lower gas purification section 2 after the liquid level in the upper gas purification section 2 reaches a high level, until the lower gas purification section 2 reaches a designated liquid level. The circulating hot water is then connected to maintain the temperature of each gas purification section 2 at 25–80°C, and the circulating cooling water pipeline of the cooler 4 is simultaneously turned on.

[0062] Step B: Set the flow rate to 100 Nm 3 Acidic gas with a gauge pressure of 0.3 MPa is introduced into the device. The acidic gas passes through gas distributor 5 and enters the alkaline solution, where H2S is absorbed to form sodium hydrosulfide. The pressure in the lower gas purification section 2 is 0.25 MPa, and the pressure in the upper gas purification section 2 is 0.2 MPa. Sampling and analysis using a sampler show that the H2S concentration in gas purification section 2 is ≤10 ppm. The purified gas exits the device and is connected to the fuel gas pipeline network.

[0063] Step C: During the operation of the device, each shift takes a sample of the solution in the lower gas purification section 2 for analysis. When the absorption is saturated, the valve at the liquid product outlet N4 is opened to allow the sodium hydrosulfide product to flow by gravity to the product tank area. When the solution in the lower gas purification section 2 flows by gravity to the low liquid level, the valve at the liquid product outlet N4 is closed, and then alkali solution is injected from the liquid raw material inlet N2 until the solution in the lower gas purification section 2 rises to the designated liquid level.

[0064] Example 3

[0065] This embodiment provides an example of a method for using this device to treat CO2 in the side-stream extracted gas of an ammonia stripping unit. The composition of the acidic tail gas generated by a crude benzene hydrogenation unit is shown in Table 4.

[0066] Table 4 Composition of Acidic Gases

[0067] Components Content (vol) <![CDATA[CO2]]> 3.1％ <![CDATA[NH3]]> 84.6％ <![CDATA[H2, non-condensable gas]]> 11.2％ <![CDATA[H2O(g)]]> 1.1％

[0068] Step A: The NaOH solution injected into the environmentally friendly multi-effect automatic acid gas purification and recovery device will automatically overflow into the lower gas purification section 2 after the liquid level in the upper gas purification section 2 reaches a high level, until the lower gas purification section 2 reaches a designated liquid level. The circulating hot water is then connected to maintain the temperature of each gas purification section 2 at 25–80°C, and the circulating cooling water pipeline of the cooler 4 is simultaneously turned on.

[0069] Step B: Set the flow rate to 100 Nm 3 Acidic gas with a gauge pressure of 0.3 MPa is introduced into the device. The acidic gas passes through gas distributor 5 and enters the alkaline solution, where CO2 is absorbed to form sodium bicarbonate. The pressure in the lower gas purification section 2 is 0.25 MPa, and the pressure in the upper gas purification section 2 is 0.2 MPa. Sampling and analysis using a sampler show that the CO2 concentration in gas purification section 2 is ≤10 ppm. The purified gas exits the device and is connected to the fuel gas pipeline network.

[0070] Step C: During the operation of the device, each shift takes a sample of the solution in the lower gas purification section 2 for analysis. When the absorption is saturated, the valve at the liquid product outlet N4 is opened to allow the sodium hydrosulfide product to flow by gravity to the product tank area. When the solution in the lower gas purification section 2 flows by gravity to the low liquid level, the valve at the liquid product outlet N4 is closed, and then alkali solution is injected from the liquid raw material inlet N2 until the solution in the lower gas purification section 2 rises to the designated liquid level.

[0071] The implementation principle of this invention, an environmentally friendly multi-effect automatic acid gas purification and recovery device and its usage method, is as follows:

[0072] This system achieves multi-stage series connection in gas alkaline scrubbing and absorption, improving gas purification efficiency without producing wastewater or solid waste. Due to the high integration of equipment and small footprint, the workload of piping and equipment installation is reduced, significantly improving construction efficiency. Simultaneously, the reduced number of pipes and valves simplifies operation, increases production efficiency, and reduces the risk of misoperation and accidents. With low investment, small footprint, and short construction period, this system has excellent application potential in small-scale coal chemical and petrochemical enterprises, effectively solving environmental problems and bringing considerable economic benefits.

[0073] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An environmentally friendly, multi-effect, automatic acid gas purification and recovery device, characterized in that: The tower body (1) includes a plurality of gas purification sections (2) for placing alkaline solution arranged sequentially along the length of the tower body (1), and a head (3) is provided between adjacent gas purification sections (2) of the tower body (1). The top of the tower body (1) is provided with a gas phase product outlet and a liquid phase raw material inlet, and the bottom is provided with a liquid phase product outlet and a gas phase raw material inlet. The gas phase product outlet and the liquid phase raw material inlet are connected to the uppermost gas purification section (2), and the liquid phase product outlet and the gas phase raw material inlet are connected to the lowermost gas purification section (2). The tower body (1) is provided with a cooler (4) at the gas phase product outlet. The gas purification section (2) is provided with a gas distributor (5), a heating element (6) and a catalyst layer (7) arranged sequentially from bottom to top. A gas phase rising pipe (9) and a liquid phase falling pipe (10) are arranged through adjacent gas purification sections (2). The liquid phase falling pipe (10) is used to allow liquid to overflow from the uppermost gas purification section (2) downwards step by step. The gas purification section (2) is used to allow gas to rise from the lowermost gas purification section (2) upwards step by step. The temperature of each gas purification section (2) is kept constant between 25 and 80°C by the heating element (6).

2. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 1, characterized in that: A demister (8) is installed between the gas purification section (2) and the gas phase product outlet in the tower body (1).

3. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 2, characterized in that: The demister (8) is any one of a wire mesh demister, a baffle demister, or a cyclone demister.

4. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 1, characterized in that: The gas distributor (5) is a porous distributed type.

5. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 4, characterized in that: The opening diameter of the gas distributor (5) is 5-20 mm.

6. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 1, characterized in that: The catalyst layer (7) is a noble metal catalyst layer supported by a network structure.

7. The environmentally friendly multi-effect automatic acid gas purification and recovery device according to claim 1, characterized in that: Each gas purification section (2) is equipped with a sampling port, which is used to analyze the degree of gas purification and the absorption saturation of liquid in real time.

8. A method of using an environmentally friendly multi-effect automatic acid gas purification and recovery device, comprising the environmentally friendly multi-effect automatic acid gas purification and recovery device as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Sodium hydroxide solution is injected through the liquid phase raw material inlet. After the liquid level in the uppermost gas purification section (2) is higher than the top height of the liquid phase downcomer (10), it automatically overflows to other gas purification sections (2) through the liquid phase downcomer (10) and reaches the specified liquid level. The temperature of each gas purification section (2) is kept constant between 25 and 80°C by the heating element (6), and the cooler (4) is turned on. S2. Acidic gas is introduced through the gas phase raw material inlet and enters the sodium hydroxide solution. It passes through the sodium hydroxide solution of each gas purification section (2) in sequence through the gas riser fitting. The hydrogen sulfide in the gas is absorbed by the sodium hydroxide solution to generate sodium hydrosulfide. After being cooled by the cooler (4), the purified gas leaves the tower body (1) through the gas phase product outlet and enters the fuel gas pipeline. The condensate flows back to the uppermost gas purification section (2). After the solution in the gas purification section (2) is saturated, the sodium hydrosulfide product is discharged from the tower body (1) through the liquid product outlet and flows to the product tank area until the solution in the lowest gas purification section (2) is at the set low liquid level. Then the liquid product outlet is closed and sodium hydroxide solution is injected through the liquid raw material inlet.

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