An ultraviolet light-based blast furnace gas desulfurization circulation system and method

Abstract

The present invention belongs to the technical field of blast furnace gas desulfurization, and specifically provides a blast furnace gas desulfurization circulation system and method based on ultraviolet light, including an ultraviolet light oxygenolysis device and a wet desulfurization module. The blast furnace gas enters the ultraviolet light oxidation device for oxidation to obtain sulfur oxides; the wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain a desulfurized liquid and purified gas, and the purified gas is discharged through a pipeline network. The desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is obtained for recycling. This solution has a high degree of automation, small floor space, and low cost, and can effectively solve the problem of excessive sulfur emissions in flue gas caused by sulfur in blast furnace gas, reduce the environmental pollution impact of gas emissions, and is beneficial to the protection of the ecological environment. On the other hand, the organic solvent used to absorb sulfides is recycled repeatedly, saving resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace gas desulfurization, and particularly relates to a blast furnace gas desulfurization circulation system and method based on ultraviolet light. Background Art

[0002] With the increasingly strict national environmental protection requirements, the problem of excessive sulfur emissions in flue gas caused by sulfur in blast furnace gas has become increasingly prominent. Many enterprises have found through monitoring that the sulfur content in the flue gas after burning pure blast furnace gas exceeds the standard. Enterprises are faced with the problem of having to desulfurize blast furnace gas after combustion, which will inevitably cause each combustion user to need to carry out flue gas desulfurization, resulting in a series of problems such as difficult selection of flue gas desulfurization systems, large floor area, high investment, and large manpower input. Many steel enterprises are also considering strengthening blast furnace desulfurization to create better conditions for downstream flue gas desulfurization. Some owners are even considering blast furnace gas desulfurization.

[0003] Blast furnace gas desulfurization is a gas source treatment technology advocated by the state, but this technology is quite difficult, especially for the removal of carbonyl sulfide. For blast furnace gas with large flow rate, complex composition, and large regional differences in sulfur content, there is still no unified and stable technology. Currently, blast furnace gas desulfurization technology is still immature, mainly including dry treatment methods represented by microcrystals and wet treatment methods represented by alkali solution absorption. These desulfurization technologies are still in the theoretical and experimental exploration stage.

[0004] The microcrystalline desulfurization technology has been applied in projects. The characteristics of this technology are: it can adsorb hydrogen sulfide and carbonyl sulfide with relatively high adsorption accuracy; the adsorbent is filled in the desulfurization tower, which has certain requirements for floor area and has a certain resistance during operation. The resistance gradually increases with the adsorption amount. The adsorbent is hydrophobic and can avoid the problem of gas containing water; the structure is relatively stable and can be regenerated repeatedly. The regeneration can use hot gas (1.5% of the total amount) or hot nitrogen (the dirty gas regenerated can go to sintering); the adsorbent also has the function of removing dust and needs to be washed with water. The problems of the microcrystalline technology lie in the operation resistance and floor area. The operation resistance is relatively large in the later stage, and due to the need to set up a large desulfurization tower, the floor area is also relatively large.

[0005] In addition to the microcrystalline technology for which there are existing projects in implementation, the others are still in the technical exploration or verification stage, mainly including carbonyl sulfide hydrolysis technology, complex iron wet technology, copper-iron series wet technology, and copper-zinc metal oxides, etc.

[0006] Analyzed from a technical perspective, these technologies have problems such as large floor area, large gas resistance, and complex operation and maintenance to varying degrees. Summary of the Invention

[0007] The purpose of the present invention is to overcome the problem of great difficulty in blast furnace gas desulfurization in the prior art.

[0008] To this end, the present invention provides a blast furnace gas desulfurization circulation system based on ultraviolet light, comprising an ultraviolet photolysis oxidation device and a wet desulfurization module;

[0009] The ultraviolet photolysis oxidation device is used to receive blast furnace gas and oxidize it to obtain a primary purified gas containing sulfur oxides;

[0010] The wet desulfurization module is used to absorb the sulfur oxides in the primary purified gas by using an organic solvent to obtain a desulfurized liquid and a purified gas. The desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is obtained for recycling.

[0011] Preferably, the wet desulfurization module comprises a desulfurization tower, a circulation tank, a circulation pump and a heat exchanger;

[0012] The first inlet of the desulfurization tower is connected to the outlet of the ultraviolet photolysis oxidation device. The exhaust hole at the top of the desulfurization tower is connected to a pipe network to discharge the purified gas. The bottom of the desulfurization tower is connected to the bottom of the circulation tank through a heat exchanger. The desulfurized liquid outlet end of the circulation tank is connected to the top of the desulfurization tower after passing through the circulation pump and being cooled by the heat exchanger in sequence.

[0013] Preferably, a steam heating device is provided inside the circulation tank.

[0014] Preferably, a cooling device is provided at the desulfurized liquid outlet end of the circulation tank.

[0015] Preferably, the ultraviolet photolysis oxidation device is used to generate ultraviolet light in the 185 nm band with a wavelength range of 170 nm - 184.9 nm.

[0016] Preferably, the energy density of the ultraviolet light is 704 kJ / mol - 647 kJ / mol.

[0017] Preferably, devices for temperature detection, pressure detection, sulfur content detection and oxygen content detection are provided on both the pipeline for transporting blast furnace gas to the ultraviolet photolysis oxidation device and the pipeline for discharging the purified gas.

[0018] The present invention also provides a blast furnace gas desulfurization method based on ultraviolet light, comprising the following steps:

[0019] Step 1: Blast furnace gas enters the ultraviolet photolysis oxidation device for oxidation to obtain sulfur oxides;

[0020] Step 2: The wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain a desulfurized liquid and a purified gas. The purified gas is discharged through the pipe network. The desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is obtained for recycling.

[0021] Preferably, before the first step, it further includes: after the blast furnace gas is subjected to pressure detection, temperature detection and sulfur and oxygen content detection, it enters the ultraviolet photolysis oxidation equipment.

[0022] Preferably, the second step specifically includes: the wet desulfurization module includes a desulfurization tower, a circulation tank, a circulation pump and a heat exchanger;

[0023] In the desulfurization tower, the gas undergoes an absorption reaction with the desulfurization liquid in a countercurrent manner, and SO 2 and SO 3 in the gas are absorbed by the desulfurization liquid, and the purified blast furnace gas is transported to the blast furnace gas pipeline network;

[0024] The desulfurized liquid is enriched at the bottom of the tower and flows to the heat exchanger through a pipeline, where it exchanges heat with the desulfurized liquid that has precipitated SO 2 and SO 3 After being heated, the desulfurization liquid enters the circulation tank and then is heated by steam to precipitate sulfur oxides. The desulfurization liquid that has precipitated SO 2 and SO 3 is cooled and then transported back to the desulfurization tower to circulate for the desulfurization reaction.

[0025] Advantages of the present invention: The blast furnace gas desulfurization circulation system and method based on ultraviolet light provided by the present invention include an ultraviolet photolysis oxidation equipment and a wet desulfurization module. The blast furnace gas enters the ultraviolet photolysis oxidation equipment for oxidation to obtain sulfur oxides; the wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain desulfurized liquid and purified gas. The purified gas is discharged through the pipeline network, and the desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is obtained for recycling. This solution has a high degree of automation, small floor space, low cost, can effectively solve the problem of excessive sulfur emission in the flue gas caused by sulfur in the blast furnace gas, reduce the environmental pollution impact of gas emissions, and is beneficial to the protection of the ecological environment. On the other hand, the organic solvent used to absorb sulfides is recycled repeatedly, saving resources.

[0026] The following will further elaborate on the present invention in conjunction with the accompanying drawings. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of the blast furnace gas desulfurization circulation system and method based on ultraviolet light of the present invention.

[0028] Description of the reference numerals in the drawings: ultraviolet photolysis oxidation equipment 1, desulfurization tower 2, circulation tank 3, circulation pump 4, heat exchanger 5. Detailed Embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "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 of the present invention.

[0031] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features; in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0032] The present invention provides a blast furnace gas desulfurization circulation system based on ultraviolet light, including an ultraviolet photolysis oxidation device and a wet desulfurization module;

[0033] The ultraviolet photolysis oxidation device is used to receive blast furnace gas and perform oxidation to obtain a primary purified gas containing sulfur oxides;

[0034] The wet desulfurization module is used to absorb the sulfur oxides in the primary purified gas by using an organic solvent to obtain a desulfurized liquid and a purified gas, and the desulfurized liquid is heated to release sulfur dioxide to obtain an organic solvent for recycling.

[0035] As Figure 1 shown, after the blast furnace gas is connected from the gas system, after pressure detection, temperature detection and sulfur and oxygen content detection, it first enters the ultraviolet photolysis oxidation device 1. The ultraviolet photolysis oxidation device 1 is connected to the desulfurization tower 2 through a pipeline. The purified gas after gas desulfurization goes to the pipe network. The wet desulfurization module is composed of a desulfurization tower, a circulation tank 3, a circulation pump 4, a heat exchanger 5, etc. The circulating liquid in the desulfurization tower is in the circulation tank 3, connected to the circulation pump 4 through a pipeline. The circulation pump 4 is connected to the heat exchanger 5 through a pipeline. The heat exchanger is connected to the desulfurization tower 2 through a pipeline. The circulating liquid after desulfurization flows out from the desulfurization tower 2, is connected to the heat exchanger 5 through a pipeline, and then enters the circulation tank 3 to complete the circulation of the desulfurized liquid.

[0036] In a preferred embodiment, the ultraviolet light oxidation technology is utilized. The ultraviolet light decomposition and oxidation equipment generates ultraviolet light in a specific wavelength band (185 nm). Under the irradiation of ultraviolet light in the wavelength range of 170 nm - 184.9 nm (704 kJ / mol - 647 kJ / mol), the chemical bonds of gases such as hydrogen sulfide and carbonyl sulfide are broken, forming free atoms and various active groups. The H - S bond and C = S bond of hydrogen sulfide and carbonyl sulfide are broken. In addition, the ultraviolet light causes the oxygen molecules in the air to generate free oxygen, that is, reactive oxygen, which oxidizes hydrogen sulfide and carbonyl sulfide. Therefore, after the blast furnace gas is purified by the ultraviolet light decomposition and oxidation equipment, SO 2 and SO 3 and other inorganic substances are generated.

[0037] In a preferred embodiment, the SO 2 and SO 3 and other inorganic substances generated by ultraviolet light oxidation are absorbed by an organic solvent, and then the organic solvent is heated to release sulfur dioxide, so that the organic solvent restores its function of absorbing sulfur oxides, enabling the desulfurization liquid to be recycled.

[0038] In a preferred embodiment, the temperature, pressure, sulfur content, and oxygen content of the blast furnace gas are detected before desulfurization; the temperature, pressure, and sulfur content are detected after desulfurization is completed. By detecting the temperature, pressure, sulfur content, and oxygen content, the concentration and capacity of the organic solvent can be controlled to absorb sulfides with the highest efficiency.

[0039] Due to the adoption of the above - mentioned solution, the method of the present invention can be used to remove the main sulfur - containing components (hydrogen sulfide and carbonyl sulfide) in blast furnace gas. The specific analysis is as follows:

[0040] (1) This method uses the ultraviolet light oxidation technology. After the blast furnace gas is irradiated by ultraviolet light, the H - S bond and C = S bond of hydrogen sulfide and carbonyl sulfide are broken, and hydrogen sulfide and carbonyl sulfide are easily oxidized themselves. Therefore, after the gas is purified by this equipment, CO 2 , H 2 O, SO 2 , SO 3 and other inorganic substances are generated.

[0041] (2) The SO 2 , SO 3 and other inorganic substances generated by ultraviolet light oxidation are absorbed by an organic solvent, and then the organic solvent is heated to release sulfur dioxide, so that the organic solvent restores its function of absorbing sulfur oxides, enabling the desulfurization liquid to be recycled.

[0042] (3) Regarding the gas boost, the gas boost of the blast furnace gas decreases little after passing through the ultraviolet light decomposition and oxidation equipment, and the gas boost reduction of the gas passing through a single desulfurization tower is relatively small. Therefore, the overall gas boost reduction of the system is relatively small.

[0043] (4)Regarding the problem of system floor area, the ultraviolet photolysis oxidation equipment can be arranged in the area where the pipe network has been formed; the desulfurization tower adopts a vertical arrangement method, and the overall floor area of other auxiliary facilities is small, and it can be arranged near the desulfurization tower, which can solve the problem of floor area.

[0044] The present invention also provides a method for desulfurizing blast furnace gas based on ultraviolet light, comprising the following steps:

[0045] Step 1: The blast furnace gas enters the ultraviolet photolysis oxidation equipment for oxidation to obtain sulfur oxides;

[0046] Step 2: The wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain desulfurized liquid and purified gas. The purified gas is discharged through the pipe network, and the desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is recycled.

[0047] Reference Figure 1 , the desulfurization process of blast furnace gas provided by this method is as follows:

[0048] ① The blast furnace gas first undergoes temperature detection, pressure detection, sulfur content detection and oxygen content detection;

[0049] ② The blast furnace gas after detection enters the ultraviolet photolysis oxidation equipment 1, and hydrogen sulfide and carbonyl sulfide in the blast furnace gas are photolyzed and oxidized to SO 2 and SO 3 ;

[0050] ③ The photolyzed blast furnace gas enters the desulfurization tower 2;

[0051] ④ In the desulfurization tower 2, the gas undergoes an absorption reaction with the desulfurized liquid in a countercurrent manner, and SO 2 and SO 3 in the gas are absorbed by the desulfurized liquid, and the purified blast furnace gas is transported to the blast furnace gas pipe network; the temperature, pressure and sulfur content of the blast furnace gas are detected after desulfurization;

[0052] ⑤ In the desulfurization tower 2, the desulfurized liquid after desulfurization is enriched at the bottom of the tower and flows through a pipeline to the heat exchanger 5, where it exchanges heat with the desulfurized liquid from which SO 2 and SO 3 are precipitated, and the heated desulfurized liquid enters the circulation tank 3;

[0053] ⑥ The desulfurized liquid rich in SO 2 and SO 3 is heated by steam in the circulation tank 3 to precipitate SO 2 , SO 2 is sent to the outside for treatment through a pipeline;

[0054] ⑦ The precipitated SO 2 and SO 3The desulfurization liquid is discharged from the circulation tank 3, and after passing through the circulation pump 4, it is transported to the heat exchanger 5, where it exchanges heat with the desulfurization liquid rich in SO 2 and SO 3 to precipitate SO 2 and SO 3 The cooled desulfurization liquid is transported to the desulfurization tower 2, where a desulfurization reaction takes place;

[0055] ⑧ The desulfurization liquid completes the desulfurization cycle through ④ to ⑦.

[0056] So far, the entire set of operations for the desulfurization of blast furnace gas has been completed in the desulfurization process of blast furnace gas. This system can be fully implemented through computer system programming, thereby realizing fully automated operation of the entire process.

[0057] Advantages of the present invention: The blast furnace gas desulfurization circulation system and method based on ultraviolet light provided by the present invention include an ultraviolet photolysis oxidation device and a wet desulfurization module. The blast furnace gas enters the ultraviolet photolysis oxidation device for oxidation to obtain sulfur oxides; the wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain desulfurization liquid and purified gas. The purified gas is discharged through the pipeline network, and the desulfurization liquid releases sulfur dioxide after heating to obtain the organic solvent for recycling. This solution has a high degree of automation, small floor space, and low cost. It can effectively solve the problem of excessive sulfur emissions in the flue gas caused by sulfur in blast furnace gas, reduce the environmental pollution impact of gas emissions, and is beneficial to the protection of the ecological environment. On the other hand, the organic solvent used to absorb sulfides is recycled repeatedly, saving resources.

[0058] The above examples are only illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. Any design identical or similar to the present invention falls within the protection scope of the present invention.

Claims

1. An ultraviolet-based blast furnace gas desulfurization circulation system, characterized in that: it includes an ultraviolet photolysis oxidation device and a wet desulfurization module; the ultraviolet photolysis oxidation device is used to receive blast furnace gas and oxidize it to obtain a primary purified gas containing sulfur oxides; the wet desulfurization module is used to absorb the sulfur oxides in the primary purified gas with an organic solvent to obtain a desulfurized liquid and a purified gas, and the desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is recycled.

2. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 1, characterized in that: the wet desulfurization module includes a desulfurization tower, a circulation tank, a circulation pump and a heat exchanger; the first inlet of the desulfurization tower is connected to the outlet of the ultraviolet photolysis oxidation device, the exhaust hole at the top of the desulfurization tower is connected to a pipe network to discharge the purified gas, the bottom of the desulfurization tower is connected to the bottom of the circulation tank through a heat exchanger, and the desulfurized liquid outlet end of the circulation tank is connected to the top of the desulfurization tower after passing through the circulation pump and being cooled by the heat exchanger in sequence.

3. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 2, characterized in that: a steam heating device is provided in the circulation tank.

4. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 2, characterized in that: a cooling device is provided at the desulfurized liquid outlet end of the circulation tank.

5. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 1, characterized in that: the ultraviolet photolysis oxidation device is used to generate ultraviolet rays in the 185nm band with a wavelength range of 170nm - 184.9nm.

6. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 5, characterized in that: the energy density of the ultraviolet rays is 704kJ / mol - 647kJ / mol.

7. The ultraviolet-based blast furnace gas desulfurization circulation system according to claim 1, characterized in that: devices for temperature detection, pressure detection, sulfur content detection and oxygen content detection are provided on both the pipeline for transporting blast furnace gas to the ultraviolet photolysis oxidation device and the pipeline for discharging the purified gas.

8. An ultraviolet-based blast furnace gas desulfurization method, characterized in that, it includes the following steps: Step 1: Blast furnace gas enters the ultraviolet photolysis oxidation device for oxidation to obtain sulfur oxides; Step 2: The wet desulfurization module uses an organic solvent to absorb the sulfur oxides in the gas after ultraviolet oxidation to obtain a desulfurized liquid and a purified gas, the purified gas is discharged through the pipe network, and the desulfurized liquid is heated to release sulfur dioxide and then the organic solvent is recycled.

9. The ultraviolet-based blast furnace gas desulfurization method according to claim 8, characterized in that, before Step 1, it further includes: the blast furnace gas is subjected to pressure detection, temperature detection, sulfur content and oxygen content detection and then enters the ultraviolet photolysis oxidation device.

10. The ultraviolet-based blast furnace gas desulfurization method according to claim 8, characterized in that, Step 2 specifically includes: the wet desulfurization module includes a desulfurization tower, a circulation tank, a circulation pump and a heat exchanger; In the desulfurization tower, the gas undergoes an absorption reaction with the desulfurization liquid in a countercurrent manner, and the SO 2 and SO 3 in the gas are absorbed by the desulfurization liquid, and the purified blast furnace gas is transported to the blast furnace gas pipeline network; The desulfurized liquid is enriched at the bottom of the tower and flows through a pipeline to a heat exchanger, where it exchanges heat with the desulfurized liquid that has precipitated SO 2 and SO 3 After being heated, the desulfurized liquid enters a circulation tank and then is heated by steam to precipitate sulfur dioxide. The desulfurized liquid that has precipitated SO 2 and SO 3 is cooled and then transported to the desulfurization tower, where it circulates to carry out the desulfurization reaction.

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