Regeneration process of blast furnace gas desulfurization activated carbon

Abstract

The present application relates to a kind of blast furnace gas desulfurization activated carbon regeneration process, belong to chemical industry and environmental protection field.Process steps include: first, photocatalyst powder is placed in regeneration reactor and is imported into ultrapure water, and homogeneous dispersion solution is obtained by ultrasonic dispersion, the original particle size of adsorbed saturated active carbon catalyst to be regenerated is put into photocatalyst solution, then stirring impregnation is carried out, active carbon loaded with photocatalyst is prepared, then ultraviolet lamp is opened and desulfurization is carried out by photocatalytic oxidation, then hydrogen peroxide is imported and washed under ultrasonic conditions Desulfurization is repeated 2-3 times, finally, heating drying obtains regenerated activated carbon, and sulfuric acid radical waste water can be treated by biological method harmlessly;The regeneration process has less carbon loss rate, complete regeneration, green environmental protection, and has application potential.

Description

Technical Field

[0001] This invention belongs to the fields of chemical engineering and environmental protection, and relates to a process for regenerating activated carbon for desulfurization of blast furnace gas. Background Technology

[0002] Blast furnace gas (BFG), a combustible gas produced during blast furnace ironmaking, can be used as fuel for hot blast stoves, heating furnaces, coke ovens, boilers, etc., enabling energy reuse and reducing energy consumption in the steel industry. However, the organic and inorganic sulfur contained in blast furnace gas, when burned, generates SO2, which is emitted into the air and causes serious pollution to the ecological environment, necessitating desulfurization of blast furnace gas. Currently, blast furnace gas desulfurization generally adopts end-of-pipe treatment, that is, removing SO2 from the flue gas after combustion by blast furnace gas users. However, blast furnace gas user sites are scattered, requiring the installation of desulfurization facilities at multiple points, resulting in problems such as repeated investment and high operating costs. Therefore, source treatment of blast furnace gas is a necessary desulfurization method.

[0003] Removing sulfur-containing compounds such as H2S using solid adsorbents plays a crucial role in numerous source control processes currently under research due to its wide applicability, simple operation, and high desulfurization efficiency. Activated carbon, with its stable chemical properties, large specific surface area, and abundant surface functional groups, has become one of the most widely used solid adsorbents. The main desulfurization reactions occurring on activated carbon catalysts are as follows:

[0004] 2H₂S + O₂ → 2S↓ + 2H₂O

[0005] As the desulfurization process proceeds, the elemental sulfur generated by the desulfurization reaction continuously deposits on the surface and in the pores of the activated carbon. When the active sites of the activated carbon are completely covered by elemental sulfur, the activated carbon becomes saturated with adsorption and loses its catalytic activity.

[0006] Currently, the main methods for treating saturated activated carbon are incineration and landfill. However, these methods do not fully utilize resources and also pose secondary pollution problems. Therefore, research on the desorption, regeneration, and harmless treatment of saturated activated carbon is of great significance for environmental protection, economic benefits, and resource utilization.

[0007] Therefore, there is an urgent need for a green, environmentally friendly, simple, and efficient process for regenerating activated carbon in blast furnace gas desulfurization. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide a blast furnace gas activated carbon desulfurization and regeneration process with low carbon loss rate, thorough regeneration, and green environmental protection.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A process for regenerating activated carbon for blast furnace gas desulfurization includes the following steps:

[0011] S1 places the photocatalyst powder in ultrapure water and disperses it using ultrasound to form a homogeneous dispersion solution;

[0012] S2 stirring: The activated carbon to be regenerated is mixed with ultrapure water in a container, and the solution and catalyst are rotated by airflow stirring and container rotation.

[0013] S3 Stop stirring and irradiate the container with ultraviolet light;

[0014] S4 drains the liquid from the container and introduces hydrogen peroxide to wash the activated carbon under ultrasonic conditions.

[0015] S5 uses airflow agitation and container rotation to drive the hydrogen peroxide and activated carbon to rotate. After agitation is complete, the liquid in the container is discharged.

[0016] S6 vacuum drying container for activated carbon.

[0017] Optionally, repeat steps S4 and S5 2-3 times.

[0018] Optionally, in step S6, the activated carbon is removed from the container and then vacuum dried.

[0019] Optionally, the contents discharged from the container in steps S4 to S5 are collected. The liquid was first reduced and then oxidized by microorganisms, and finally elemental sulfur was separated.

[0020] Optionally, in step S3, the reaction occurring within the system is as follows:

[0021] Optionally, in steps S4-S5, the reactions occurring within the system are as follows:

[0022] Optionally, in step S1, the ultrasonic dispersion time is 1 to 2 hours.

[0023] Optionally, the mass ratio of photocatalyst: activated carbon: water is 1:10:30 to 500.

[0024] Optionally, in step S2, the stirring time is 2 to 3 hours.

[0025] Optionally, in step S3, the ultraviolet irradiation time is 2 to 4 hours.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. The regeneration process of this invention is green and efficient. Compared with the organic regeneration solvents used in traditional regeneration methods, hydrogen peroxide significantly reduces pollution.

[0028] 2. The regeneration temperature of this invention is relatively low and can be carried out at room temperature. The regeneration process does not change or damage the original structure of the activated carbon, and the adsorption performance after regeneration is close to that of the fresh adsorbent.

[0029] 3. The process operation of the present invention can be completed on a single device, saving space and reducing equipment investment.

[0030] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 This is a flowchart of the present invention;

[0033] Figure 2 This is a diagram of the device according to the present invention.

[0034] Attached reference numerals: 1. Motor; 2. Ultraviolet lamp; 3. Air inlet pipe; 4. Ultrasonic generator; 5. Water inlet pipe; 6. Drain pipe; 7. Inner reaction vessel; 8. Activated carbon to be regenerated; 9. Small air inlet pipe; 10. Reactor body; 11. Reactor lid. Detailed Implementation

[0035] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Please see Figures 1-2 The process steps of the present invention are as follows:

[0039] Preparation of activated carbon loaded with photocatalyst: Photocatalyst powder is placed in a regeneration reactor and ultrapure water is introduced. The mixture is ultrasonically dispersed for 1-2 hours to obtain a homogeneous dispersion solution. The original particle size of the activated carbon 8 to be regenerated, which is saturated with adsorption, is added to the photocatalyst solution. The mixture is then stirred and impregnated for 2-3 hours to obtain activated carbon loaded with photocatalyst. To prevent the rotation of the stirring blades from damaging the original particle size catalyst, a combination of airflow stirring (introducing compressed air) and the rotation of the reactor body 10 itself to drive the rotation of the solution and catalyst is used for stirring.

[0040] Photocatalytic oxidation desulfurization: Turn on ultraviolet lamp 2 to irradiate the regeneration system for 2-4 hours. The system mainly includes the following reactions:

[0041]

[0042] Hydrogen peroxide washing for desulfurization: Open the drain pipe 6 at the bottom of the reactor to drain the photocatalyst solution. Then, turn on the ultrasonic generator 4 on the reactor and introduce hydrogen peroxide to wash the activated carbon under ultrasonic conditions. When the hydrogen peroxide flow rate reaches the preset value, close the inlet pipe 5 to stop the hydrogen peroxide flow. Then, stir using airflow agitation and the rotation of the inner reactor 7 to rotate the solution and catalyst for 0.5–1 hour. After stirring, open the drain pipe 6 at the bottom of the reactor to drain the waste liquid. Repeat the above steps, introducing hydrogen peroxide again to wash the activated carbon under ultrasonic conditions, repeating 2–3 times.

[0043] Fe can also be added to hydrogen peroxide 2+ Cu 2+ The addition of metal ions can enhance the activated carbon's ability to generate hydroxyl radicals (·OH), thereby increasing its oxidizing power. Furthermore, the metal ions remaining on the activated carbon can replenish its active sites, improving its desulfurization efficiency. The main reactions occurring in the system are:

[0044]

[0045] Heating and drying: Take out the activated carbon from the reaction vessel and dry it by vacuum drying. At the same time, the vacuum method can also remove the impurity gases adsorbed in the activated carbon. The heating temperature is set to 80-100℃ and the drying time is 1-2 hours.

[0046] Biological treatment containing Wastewater: Collection containing Wastewater can be reduced and then oxidized through microbial action, ultimately separating elemental sulfur.

[0047] Process route diagram as follows Figure 1 As shown.

[0048] This embodiment provides a regeneration device for activated carbon used in blast furnace gas desulfurization, the device comprising:

[0049] Motor 1 converts electrical energy into mechanical energy, which drives the shaft and the inner reaction vessel 7 to rotate, thereby stirring the solution and catalyst by rotating them.

[0050] Ultraviolet lamp 2 emits ultraviolet light to irradiate the regeneration system, promoting the photocatalytic reaction in the regeneration process;

[0051] Intake pipe 3 introduces compressed air to replenish oxygen to the regeneration system and also serves to agitate the airflow.

[0052] An ultrasonic generator 4 is installed in the reactor body 10 to generate ultrasonic waves, thus placing the regeneration system in an ultrasonic environment.

[0053] Water inlet pipe 5 and water outlet pipe 6 are used to introduce / discharge liquid into / from the reactor.

[0054] The reactor lid 11 is a detachable lid with a ring handle and a round hole in the center, through which the shaft of the inner reactor 7 can extend to the outside of the reactor and connect to the motor 1.

[0055] The inner reaction tank 7 is a cylindrical container placed inside the reactor body 10. The activated carbon 8 to be regenerated is placed inside. The tank body is covered with small holes, the size of which is smaller than that of the activated carbon. The liquid inside the reactor can enter the inner reaction tank 7. There is no lid on the top of the tank, and ultraviolet light can directly irradiate it.

[0056] The reactor body 10 provides a regeneration site for the regeneration system. The bottom of the reactor is also equipped with an air inlet pipe 9, through which compressed air can enter the reactor for airflow stirring.

[0057] The regeneration operation plan is as follows:

[0058] 1. Place a certain amount of photocatalyst powder in a reaction vessel, open the water inlet pipe 5 to introduce ultrapure water, and at the same time turn on the ultrasonic generator 4 to ultrasonically disperse the powder and form a homogeneous dispersion solution.

[0059] 2. Load the activated carbon to be regenerated into the inner reaction tank 7, then place the inner reaction tank 7 in a suitable position on the reactor body 10, and install the air inlet pipe 3.

[0060] 3. The inner reaction vessel 7 is connected to the motor 1 via a shaft, and the motor 1 can be fixed above the reaction vessel by a bracket;

[0061] 4. Install the lid onto the vessel body, turn on the motor 1, the air inlet pipe 3 and the air inlet pipe 9 at the bottom of the reactor to introduce compressed air, and stir by airflow stirring and the rotation of the inner reaction vessel 7 driving the solution and catalyst to rotate.

[0062] 5. After stirring stops, turn on the ultraviolet lamp 2 to irradiate the regeneration system;

[0063] 6. Open the drain pipe 6 at the bottom of the reactor to drain the photocatalyst solution. Then turn on the ultrasonic generator 4 on the reactor and introduce hydrogen peroxide to wash the activated carbon under ultrasonic conditions.

[0064] 7. Once the hydrogen peroxide flow rate reaches the preset value, close the inlet pipe 5 to stop the flow of hydrogen peroxide; then, stir using airflow stirring and the rotation of the reaction tank 7 itself to drive the solution and catalyst to rotate.

[0065] 8. After stirring, open drain pipe 6 under the reactor to drain the waste liquid. Repeat the above steps, then pass hydrogen peroxide through the activated carbon under ultrasonic conditions to wash it, repeating 2-3 times.

[0066] 9. Remove the activated carbon from the reactor and dry it using a vacuum drying method.

[0067] Implementation Example 1

[0068] Preparation of photocatalyst-loaded activated carbon: Place photocatalyst powder in a reaction vessel, open the water inlet pipe 5 to introduce ultrapure water, and simultaneously turn on the ultrasonic generator 4 to ultrasonically disperse the carbon and form a homogeneous dispersion solution; load the activated carbon to be regenerated into the inner reaction vessel 7, then place the inner reaction vessel 7 in a suitable position on the reaction vessel body 10 and install the air inlet pipe 3; connect the inner reaction vessel 7 to the motor 1 via a shaft, and the motor 1 can be fixed above the reaction vessel by a bracket; install the vessel lid on the vessel body, open the motor 1, the air inlet pipe 3, and the small air inlet pipe 9 at the bottom of the reaction vessel to introduce compressed air, and stir the solution and catalyst by airflow stirring and the rotation of the inner reaction vessel 7 itself;

[0069] Ultrasonic frequency: 80KHZ, ultrasonic time: 2h, photocatalyst: activated carbon: water (mass ratio) = 1kg:10kg:400kg;

[0070] Photocatalytic oxidation desulfurization: After stirring is stopped, turn on the ultraviolet lamp 2 to irradiate the regeneration system for 3 hours. The power of the ultraviolet lamp is 300W.

[0071] Hydrogen peroxide washing for desulfurization: Open the drain pipe 6 at the bottom of the reactor to discharge the photocatalyst solution. Then, turn on the ultrasonic generator 4 on the reactor and introduce hydrogen peroxide to wash the activated carbon under ultrasonic conditions. When the hydrogen peroxide flow rate reaches the preset value, close the inlet pipe 5 to stop the hydrogen peroxide flow. Then, stir using airflow agitation and the rotation of the inner reaction tank 7 to drive the solution and catalyst rotation. After stirring, open the drain pipe 6 at the bottom of the reactor to discharge the waste liquid. Repeat the above steps, introducing hydrogen peroxide again to wash the activated carbon under ultrasonic conditions, repeating twice.

[0072] Ultrasonic frequency: 80kHz, ultrasonic time: 0.5h; activated carbon: hydrogen peroxide (mass ratio) = 1.25kg: 500kg;

[0073] Heating and drying: Remove the activated carbon from the reactor and dry it by vacuum drying. The heating temperature is set to 80℃ and the drying time is 2 hours.

[0074] Implementation Example 2

[0075] Preparation of photocatalyst-loaded activated carbon: Place photocatalyst powder in a reaction vessel, open the water inlet pipe 5 to introduce ultrapure water, and simultaneously turn on the ultrasonic generator 4 to ultrasonically disperse the carbon and form a homogeneous dispersion solution; load the activated carbon to be regenerated into the inner reaction vessel 7, then place the inner reaction vessel 7 in a suitable position on the reaction vessel body 10 and install the air inlet pipe 3; connect the inner reaction vessel 7 to the motor 1 via a shaft, and the motor 1 can be fixed above the reaction vessel by a bracket; install the vessel lid on the vessel body, open the motor 1, the air inlet pipe 3, and the small air inlet pipe 9 at the bottom of the reaction vessel to introduce compressed air, and stir the solution and catalyst by airflow stirring and the rotation of the inner reaction vessel 7 itself;

[0076] Ultrasonic frequency: 60kHz, ultrasonic time: 2.5h; photocatalyst: activated carbon: water (mass ratio) = 1.25kg: 12.5kg: 500kg;

[0077] Photocatalytic oxidation desulfurization: After stirring is stopped, turn on the ultraviolet lamp 2 to irradiate the regeneration system for 2 hours. The power of the ultraviolet lamp is 400W.

[0078] Hydrogen peroxide washing for desulfurization: Open the drain pipe 6 at the bottom of the reactor to discharge the photocatalyst solution. Then, turn on the ultrasonic generator 4 on the reactor and introduce hydrogen peroxide to wash the activated carbon under ultrasonic conditions. When the hydrogen peroxide flow rate reaches the preset value, close the inlet pipe 5 to stop the hydrogen peroxide flow. Then, stir using airflow agitation and the rotation of the inner reaction tank 7 to drive the solution and catalyst rotation. After stirring, open the drain pipe 6 at the bottom of the reactor to discharge the waste liquid. Repeat the above steps, introducing hydrogen peroxide again to wash the activated carbon under ultrasonic conditions, repeating 3 times.

[0079] Ultrasonic frequency: 60kHz, ultrasonic time: 1h; activated carbon: hydrogen peroxide (mass ratio) = 1.25kg: 500kg;

[0080] Heating and drying: Take out the activated carbon from the reaction vessel and dry it by vacuum drying. The heating temperature is set to 100℃ and the drying time is 1 hour.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A process for regenerating activated carbon for blast furnace gas desulfurization, characterized in that, Includes the following steps: S1 Place the photocatalyst powder in ultrapure water and disperse it using ultrasound for 1-2 hours to form a homogeneous dispersion solution; S2 stirring: The activated carbon to be regenerated is mixed with ultrapure water in a container. The solution and catalyst are rotated by airflow stirring and container rotation. The stirring time is 2-3 hours to prepare activated carbon loaded with photocatalyst. S3. Stop stirring and irradiate the container with ultraviolet light for 2-4 hours. The reaction that occurs in the system is: S 0 +O2→SO4 2- ; S4 drains the liquid from the container and introduces hydrogen peroxide to wash the activated carbon under ultrasonic conditions. S5 uses airflow agitation and container rotation to drive the hydrogen peroxide and activated carbon to rotate. After agitation is complete, the liquid in the container is discharged. S6 vacuum drying container for activated carbon.

2. The blast furnace gas desulfurization activated carbon regeneration process according to claim 1, characterized in that: Repeat steps S4 and S5 2-3 times.

3. The blast furnace gas desulfurization activated carbon regeneration process according to claim 1, characterized in that: In step S6, the activated carbon is removed from the container and then vacuum dried.

4. The blast furnace gas desulfurization activated carbon regeneration process according to claim 1, characterized in that: Collect SO4-containing substances discharged from the container in steps S4-S5 2- The liquid was first reduced and then oxidized by microorganisms, and finally elemental sulfur was separated.

5. The blast furnace gas desulfurization activated carbon regeneration process according to claim 1, characterized in that: In steps S4-S5, the reactions occurring within the system are: S 0 +H₂O₂→SO₄ 2- .

6. The blast furnace gas desulfurization activated carbon regeneration process according to claim 1, characterized in that, The mass ratio of photocatalyst, activated carbon, and water is 1:10:30~50.

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