A doped activated carbon adsorption material containing a sulfoxide type sulfur-containing functional group, and a preparation method and application thereof

Abstract

The application discloses a kind of active carbon adsorption material of doping sub-sulfoxide type sulfur-containing functional group and its preparation method and application, including the following steps: porous carbon is reacted with SO2-containing gas at 700~900 ℃ to realize sulfur element doping;After reaction is completed, sulfur-doped active carbon is rapidly cooled and reduced to room temperature within 5-60s under inert atmosphere, to obtain the active carbon adsorption material of doping sub-sulfoxide type sulfur-containing functional group.When sulfur doping is realized at 700~900 ℃, then the sulfur-doped active carbon is rapidly cooled and reduced in inert atmosphere, the active carbon adsorption material of doping sub-sulfoxide type sulfur-containing functional group can be obtained, and the adsorption material has excellent sulfur dioxide adsorption performance.

Description

Technical Field

[0001] This invention belongs to the field of activated carbon adsorption material preparation technology, specifically relating to an activated carbon adsorption material doped with sulfoxide type sulfur-containing functional groups, its preparation method and application. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] In recent years, with the continuous development and utilization of new energy technologies, the proportion of coal consumption in my country has been declining year by year. However, due to the huge domestic economic size and the continuous increase in total energy consumption, the national coal consumption is constantly rising, mainly in thermal power generation, industrial consumption, and heating. Therefore, the energy consumption model using coal as fuel and raw material will remain the main energy source in my country in the short term, and the SO2 and other gaseous pollutants generated during its utilization process still require in-depth purification. Activated carbon dry flue gas desulfurization technology, which uses porous carbon materials as desulfurization adsorbents, has attracted widespread attention due to its advantages such as low water consumption, high desulfurization efficiency, recyclable adsorbents, and high-value sulfur byproducts. It is considered the most promising green desulfurization technology for large-scale application.

[0004] Currently, the activated carbon dry desulfurization technology successfully applied in the steel industry mainly includes activated carbon preparation, adsorption, regeneration, and the production of sulfuric acid from SO2-rich desorbed gas. The process flow is long and the system is complex. During operation, the SO2 adsorption performance of activated carbon is crucial. A high SO2 adsorption capacity (sulfur capacity) of activated carbon results in a low mass flow rate of the adsorbent in the desulfurization reactor, a smaller installed amount of activated carbon in the system, reduced reactor volume / footprint and operating energy consumption, and better overall system economy. Therefore, improving the working sulfur capacity of activated carbon while ensuring desulfurization efficiency is a common key issue for the successful application of this technology. Modifying activated carbon by incorporating heteroatoms during preparation is a common method to improve its performance. Current research mainly involves incorporating non-metallic elements such as N and O, or metallic elements such as Cu, Fe, Mn, V, and Ni. However, this increases the cost of activated carbon and introduces a large number of heteroatoms into the desulfurization system, indirectly increasing the post-treatment costs of waste carbon / coke. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide an activated carbon adsorbent material doped with sulfoxide-type sulfur-containing functional groups, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a sulfoxide-doped activated carbon adsorbent material containing sulfur functional groups, comprising the following steps:

[0008] Sulfur doping is achieved by reacting porous carbon with SO2-containing gas at 700–900℃.

[0009] After the reaction is complete, the sulfur-doped activated carbon is rapidly cooled to room temperature within 5-60 seconds under an inert atmosphere to obtain a sulfoxide-doped activated carbon adsorbent containing sulfur functional groups.

[0010] The sulfoxide-type sulfur-containing functional group refers to the sulfur-containing functional group corresponding to the fitting peaks at the positions of 166 eV and 167.18 eV, respectively, of the binding energies of Sp3 / 2 and Sp1 / 2 in XPS S2p analysis of carbon materials.

[0011] Through experiments, the inventors discovered that when sulfur doping is achieved at 700–900℃, and then the sulfur-doped activated carbon is rapidly cooled in an inert atmosphere, an activated carbon adsorbent material doped with sulfoxide-type sulfur-containing functional groups can be obtained. This adsorbent material has excellent sulfur dioxide adsorption performance.

[0012] The inventors discovered that coal and biomass precursors naturally contain low levels of sulfur, typically less than 1% by mass. Traditional physical activation methods for activated carbon preparation, using CO2, H2O, and O2 as activators for pore-forming and expanding, do not introduce any sulfur, resulting in activated carbon with very low sulfur content. Reducing SO2 gas with carbon materials at high temperatures directly produces CO2 and elemental sulfur (carbothermic reduction of SO2: SO2 + C = CO2 + S). Current research focuses primarily on sulfur yield, aiming to convert SO2 pollutants into high-value resources. On the other hand, according to the carbothermic reduction of SO2 to produce sulfur, the S atoms released from SO2 molecules bond with C atoms, forming a CS complex on the carbon matrix, thus significantly increasing the sulfur content in activated carbon. The doping of sulfur in activated carbon has two main promoting effects on the desulfurization reaction: first, sulfur-containing functional groups can significantly increase the van der Waals interaction with SO2 molecules; second, sulfur-containing functional groups change the charge distribution on the surface of carbon materials, strengthen the polar interaction with H2O molecules, thereby making the carbon materials exhibit "hydrophilic" properties and improving the hydration reaction performance (hydration reaction: *SO3+H2O=H2SO4, * is the SO2 adsorption active site).

[0013] Currently, the preparation of sulfur-doped activated carbon mainly utilizes sulfur-containing chemical sources (such as thiourea, dipotassium 1,4-piperazine diethanesulfonate, potassium aminosulfonate, potassium 6-hydroxy-2-naphthalenesulfonate, potassium propanesulfonate, concentrated sulfuric acid, cysteine, sulfonates, trithiocyanate, and at least one elemental sulfur as a dopant) mixed with a carbon-rich precursor, and obtained by grinding, impregnation, high-temperature calcination, and cooling. The preparation steps are complex and costly. This invention proposes to prepare sulfoxide-type activated carbon adsorbent materials with sulfur-containing functional groups by reducing SO2 gas at high temperature using carbon-rich materials, and sulfur is produced as a byproduct. It has the advantages of simple preparation steps and low cost.

[0014] In step (1), carbon-rich precursors such as coal and biomass are crushed and ground into powder with a particle size distribution range of 50μm to 5mm. The smaller the particle size, the larger the contact area with SO2 in the later stage, and the more complete the reaction. For some materials that are difficult to crush, they can be dried and embrittled at low temperature first, and then crushed and screened after cooling. The low temperature drying conditions are: heating to 200 to 300℃ at a rate of 5 to 20℃ / min under N2 atmosphere, and holding at that temperature for 0.5 to 3h.

[0015] Coal and biomass contain a significant amount of moisture and volatile matter. The high-temperature, inert atmosphere in step (2) allows for the complete release of moisture and volatile matter from the carbon-rich particles. This process serves two main purposes: 1. The release of moisture and volatile matter creates initial pores, increasing the contact area and reaction depth with SO2; 2. It reduces tar precipitation and condensation during SO2 reduction, improving the purity of the sulfur product. The high-temperature pyrolysis conditions are: heating to 700–900℃ at a rate of 5–20℃ / min under a N2 atmosphere, and holding at that temperature for 0.5–3 hours.

[0016] In step (3), the atmosphere is switched to SO2 at the target temperature of 700-900℃, and the carbon reduction SO2 reaction SO2+C=CO2+S occurs. The reaction process has two effects on the carbon material. First, SO2 and the product CO2 react with C to produce the effects of "pore-forming" and "pore-expanding" (SO2+C=CO2+S, CO2+C=2CO). Second, the S atoms dissociated from the SO2 molecules will form bonds with the C atoms to form CS complexes on the carbon matrix (thiol RSH, thiophene type CS, sulfone type RSOO, sulfoxide type RSO, inorganic sulfur SO4). 2- This significantly increases the sulfur content in activated carbon. Specific reaction conditions: SO2 concentration controlled at 5–50 vol%, reaction time 0.5–2 h, and space velocity 1500–30000 h⁻¹. -1 (Corresponding to a gas-solid reaction time of 0.05 to 1 s).

[0017] In the thiol RSH, S has a -2 valence, and the binding energies of the corresponding Sp3 / 2 and Sp1 / 2 fitting peaks in XPS analysis are 162.5 eV and 163.68 eV, respectively; in the thiophene-type CS, S has a -2 valence, and the binding energies of the corresponding Sp3 / 2 and Sp1 / 2 fitting peaks in XPS analysis are 164.1 eV and 165.32 eV, respectively; in the sulfone-type RSOO, S has a +6 valence, and the binding energies of the corresponding Sp3 / 2 and Sp1 / 2 fitting peaks in XPS analysis are 168 eV and 169.18 eV, respectively; the inorganic sulfur SO4 2- The S in the figure represents a +6 valence, and the binding energies of the corresponding Sp3 / 2 and Sp1 / 2 fitting peaks in the XPS analysis are 169.5 eV and 170.68 eV, respectively.

[0018] To preserve the sulfur-containing functional groups formed on the surface of activated carbon during the carbon reduction of SO2 reaction, a rapid annealing and cooling method is adopted under N2 atmosphere.

[0019] In some embodiments, the porous carbon is prepared by crushing a carbon-rich precursor and then subjecting it to high-temperature pyrolysis to obtain porous carbon with an initial pore structure.

[0020] Preferably, the carbon-rich precursor is coal or biomass.

[0021] Preferably, the particle size of the crushed carbon-rich precursor is 50 μm to 5 mm. The smaller the particle size, the larger the contact area with SO2 in the later stage, and the more complete the reaction. For some difficult-to-crush substances, they can be dried and embrittled at low temperature first, then crushed and sieved after cooling. The low-temperature drying conditions are: heating to 200 to 300°C at a rate of 5 to 20°C / min under N2 atmosphere, and holding at this temperature for 0.5 to 3 hours.

[0022] In some embodiments, the SO2 concentration in the SO2-containing gas is 5–50 vol%.

[0023] Preferably, the reaction time for sulfur doping is 0.5–2 h, and the space velocity is 1500–30000 h⁻¹. -1 (Corresponding to a gas-solid reaction time of 0.05 to 1 s).

[0024] In some embodiments, the prepared sulfoxide-doped activated carbon adsorbent material containing sulfur functional groups is stored in a drying device to prevent deterioration due to contact with moisture in the air.

[0025] In some embodiments, the method for rapidly cooling sulfur-doped activated carbon is as follows:

[0026] Quickly disconnect the power supply to the electric heating furnace to stop the electric heating components from working; remove the reaction tube containing the sample from the heating area and, under the protection of an inert nitrogen atmosphere, quickly move it into a liquid nitrogen / dry ice / ice-water mixture / external room temperature environment, where it will cool to room temperature for 5–60 seconds.

[0027] Alternatively, the reaction tube / vessel can be moved to room temperature, and a fan can be used to blow cold air onto the outer wall of the reaction tube to rapidly cool the product inside, cooling it to room temperature within 5–60 seconds. Different cooling methods can be selected depending on the amount of reactants.

[0028] If the rapid cooling experimental preparation method is not adopted, the sulfur oxide functional group (sulfone / sulfoxide type) formed during the carbothermic reduction reaction will decompose or transform into the thiophene type sulfur functional group with higher thermal stability at high temperature. Therefore, the rapid cooling experimental method is crucial for obtaining the sulfoxide-rich activated carbon material of this invention.

[0029] Secondly, the present invention provides an activated carbon adsorbent material doped with sulfoxide-type sulfur-containing functional groups, which is prepared by the aforementioned preparation method.

[0030] Thirdly, the present invention provides the application of the doped sulfoxide-type sulfur-containing activated carbon adsorbent material in the removal of SO2 from flue gas.

[0031] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows:

[0032] This invention provides a method for preparing activated carbon adsorbent material doped with sulfoxide-type sulfur-containing functional groups. The activated carbon prepared by this method has high sulfur activity. Using the activated carbon doped with sulfoxide-type sulfur-containing functional groups described in this invention as an adsorbent for SO2 removal from flue gas can significantly improve the SO2 adsorption capacity of the activated carbon. Furthermore, the method of this invention can completely couple the activated carbon-based dry flue gas desulfurization process, allowing the activated carbon preparation and high-value sulfur recovery processes to be completed in the same reactor, greatly reducing the complexity and operating cost of the desulfurization system and significantly improving the system's economic efficiency. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0034] Figure 1 The peaks of each functional group of XPS S2p in the embodiments of the present invention are shown.

[0035] Figure 2 This is a scatter plot of total sulfur content and sulfur capacity in XPS in an embodiment of the present invention.

[0036] Figure 3 This is a scatter plot of sulfoxide content and sulfur capacity in an embodiment of the present invention. Detailed Implementation

[0037] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] The present invention will be further described below with reference to the embodiments.

[0039] Example 1

[0040] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0041] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0042] (3) Spread 0.25g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), raise the temperature from room temperature to 600℃ at a rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0043] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 10 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0044] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 1.558%, and the sulfur yield is 1.444%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0045] The sulfur content of the activated carbon material doped with sulfoxide type sulfur element obtained in step (4) is 4.078%, and the content of sulfoxide type functional group is about 0.22% according to the functional group type analysis.

[0046] The desulfurization test of the obtained sulfoxide-doped sulfur-containing activated carbon material under a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h) showed that the SO2 adsorption capacity per unit mass of activated carbon was 18.94 mg / g.

[0047] Example 2

[0048] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0049] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0050] (3) Spread 1g of coal powder carbonization material in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), raise the temperature from room temperature to 600℃ at a rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 equilibrium), flow rate controlled at 200ml / min) and react for 30min. After the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0051] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 20 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0052] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 3.163%, and the sulfur yield is 2.974%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0053] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 3.584%, and the content of sulfoxide functional groups is about 0.33% based on the functional group type analysis.

[0054] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 26.13 mg / g.

[0055] Example 3

[0056] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0057] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0058] (3) Spread 4g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), raise the temperature from room temperature to 600℃ at a rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0059] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 30 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0060] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is approximately 11.1%, and the sulfur yield is 10.987%. Therefore, the sulfur-containing product in the reaction is mainly sulfur. The sulfur-doped activated carbon material obtained in step (4) has a sulfur content of 2.527%, and the content of sulfoxide functional groups is approximately 0.22% based on functional group type analysis. The obtained sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as the equilibrium gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h), and the SO2 adsorption capacity per unit mass of activated carbon was found to be 36.43 mg / g.

[0061] Example 4

[0062] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0063] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0064] (3) Spread 0.25g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 700℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 equilibrium), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0065] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 50 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0066] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 2.976%, and the sulfur yield is 2.805%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0067] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 8.438%, and the content of sulfoxide functional groups is about 0.9% based on the functional group type analysis.

[0068] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 29.58 mg / g.

[0069] Example 5

[0070] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0071] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0072] (3) Spread 1g of coal powder carbonization material in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 700℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0073] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 55 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0074] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 11.454%, and the sulfur yield is 10.951%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0075] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 8.501%, and the content of sulfoxide functional groups is about 0.78% based on the functional group type analysis.

[0076] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 48.88 mg / g.

[0077] Example 6

[0078] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0079] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0080] (3) Spread 4g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 700℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0081] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 15 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0082] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 48.768%, and the sulfur yield is 48.109%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0083] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 8.42%, and the content of sulfoxide functional groups is about 1.26% based on the functional group type analysis.

[0084] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 59.21 mg / g.

[0085] Example 7

[0086] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0087] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0088] (3) Spread 0.25g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 800℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0089] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 30 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0090] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 29.759%, and the sulfur yield is 29.25%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0091] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 11.936%, and the content of sulfoxide functional groups is about 1.44% based on the functional group type analysis.

[0092] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 88.13 mg / g.

[0093] Example 8

[0094] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0095] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0096] (3) Spread 1g of coal powder carbonization material in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 800℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0097] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 40 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0098] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 78.394%, and the sulfur yield is 77.035%. Therefore, the sulfur-containing product in the reaction is mainly sulfur.

[0099] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 11.798%, and the content of sulfoxide functional groups is about 2.18% based on the functional group type analysis.

[0100] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 95.44 mg / g.

[0101] Example 9

[0102] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0103] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0104] (3) Spread 4g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), raise the temperature from room temperature to 800℃ at a rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0105] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 40 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0106] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 99.956%, and the sulfur yield is 72.417%. Therefore, the sulfur-containing products in the reaction are mainly sulfur and carbonyl sulfur.

[0107] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 8.996%, and the content of sulfoxide functional groups is about 1.215% based on the functional group type analysis.

[0108] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 81.97 mg / g.

[0109] Example 10

[0110] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0111] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0112] (3) Spread 1g of coal powder carbonization material in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 900℃ at a rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 equilibrium), flow rate controlled at 200ml / min) and react for 30min. After the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0113] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 50 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0114] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 99.804%, and the sulfur yield is 81.19%. Therefore, the sulfur-containing products in the reaction are mainly sulfur and carbonyl sulfur.

[0115] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 13.277%, and the content of sulfoxide functional groups is about 1.60% based on the functional group type analysis.

[0116] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 78.88 mg / g.

[0117] Example 11

[0118] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0119] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0120] (3) Spread 2g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 900℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0121] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 30 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0122] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 99.959%, ​​and the sulfur yield is 59.477%. Therefore, the sulfur-containing products in the reaction are mainly sulfur and carbonyl sulfur.

[0123] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 10.216%, and the content of sulfoxide functional groups is about 1.84% based on the functional group type analysis.

[0124] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 105.25 mg / g.

[0125] Example 12

[0126] (1) The lignite is crushed and screened to 80-150 mesh (average particle size of 140 μm) to obtain coal powder;

[0127] (2) Place the pulverized coal in a vertical tube furnace and heat it from room temperature to 900°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate controlled at 500 ml / min). Hold the temperature at the highest temperature for 1 hour to carry out pyrolysis and carbonization treatment. After heat treatment, remove the pulverized coal at room temperature under a nitrogen atmosphere to obtain pulverized coal carbonized material.

[0128] (3) Spread 4g of coal powder carbonization material evenly in the quartz tube of the vertical tube furnace. Under nitrogen atmosphere (flow rate controlled at 500ml / min), heat from room temperature to 900℃ at a heating rate of 10℃ / min. Switch to SO2 gas (SO2 concentration of 10% (N2 balance), flow rate controlled at 200ml / min), react for 30min, and after the reaction is completed, switch to nitrogen atmosphere (flow rate controlled at 500ml / min).

[0129] (4) Then, under an inert atmosphere, the sulfur-doped activated carbon is rapidly cooled to room temperature within 50 seconds to obtain the sulfur-doped activated carbon adsorbent material.

[0130] Specifically, in step (3), the SO2 conversion rate of carbon reducing SO2 to sulfur is about 99.986%, and the sulfur yield is 46.248%. Therefore, the sulfur-containing products in the reaction are mainly sulfur and carbonyl sulfur.

[0131] The sulfur content of the activated carbon material doped with sulfur obtained in step (4) is 10.087%, and the content of sulfoxide functional groups is about 1.78% based on the functional group type analysis.

[0132] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 91.29 mg / g.

[0133] In summary, activated carbon prepared by reducing SO2 with carbon has a significantly increased sulfur content and exhibits good desulfurization effect. The test results are shown in Table 1.

[0134] Comparative Example 1

[0135] The difference from Example 12 is that in step (4), the sample is naturally cooled to room temperature under an inert atmosphere (natural cooling refers to the reaction tube containing the sample being naturally cooled in an electric heating furnace. Because there is a large amount of heat-insulating material in the heating furnace, a large amount of heat is stored, so the time required to cool to room temperature is about 3 hours), thus obtaining activated carbon adsorbent material doped with sulfur.

[0136] The sulfur-doped activated carbon material obtained has a sulfur content of 8.03%, and the content of sulfoxide functional groups is about 0.2% based on functional group type analysis.

[0137] The sulfur-doped activated carbon material was tested for desulfurization in a flue gas atmosphere (test conditions: simulated flue gas flow rate 200 ml / min, SO2 concentration 500 ppm, 8 vol% H2O, 6 vol% O2, N2 as balance gas, adsorption temperature 75℃, activated carbon amount 0.2 g, adsorption time 2 h). The SO2 adsorption capacity per unit mass of activated carbon was found to be 25.51 mg / g.

[0138] Table 1. Test results of sulfur content and SO2 adsorption capacity of sulfur-doped activated carbon adsorbent materials.

[0139]

[0140] As can be seen from the experimental data in Table 1, the sulfur-doped activated carbon adsorbents prepared in Examples 1-12 have high sulfur content; this indicates that the reaction process of carbon reducing SO2 to sulfur promotes the enrichment of sulfur on the surface of activated carbon, and the proportion of sulfur doping is easy to control, as shown in the attached table. Figure 1 As shown, there is no obvious linear relationship between the total sulfur content of activated carbon and its sulfur adsorption capacity, indicating that using the total sulfur content alone as an indicator to evaluate the SO2 adsorption performance of the adsorbent is inappropriate; as shown in the attached figure. Figure 2 As shown, with the increase of the amount of sulfoxide functional groups in activated carbon, the adsorption capacity of SO2 increases linearly. Therefore, the increase of the content of sulfoxide functional groups in activated carbon can greatly improve the adsorption capacity of the material for SO2.

[0141] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an activated carbon adsorbent material doped with sulfoxide-type sulfur-containing functional groups, characterized in that: Includes the following steps: Sulfur doping is achieved by reacting porous carbon with SO2-containing gas at 700~900℃. After the reaction is complete, the sulfur-doped activated carbon is rapidly cooled to room temperature within 5-60 seconds under an inert atmosphere to obtain a sulfoxide-doped activated carbon adsorbent containing sulfur functional groups. The SO2-containing gas has an SO2 concentration of 5-50 vol%. The reaction time for sulfur doping is 0.5 to 2 hours.

2. The method for preparing the doped sulfoxide-type activated carbon adsorbent material with sulfur-containing functional groups according to claim 1, characterized in that: The method for preparing the porous carbon is as follows: after crushing the carbon-rich precursor, it is subjected to high-temperature pyrolysis treatment to obtain porous carbon with an initial pore structure.

3. The method for preparing the doped sulfoxide-type activated carbon adsorbent material with sulfur-containing functional groups according to claim 2, characterized in that: The carbon-rich precursor is coal or biomass.

4. The method for preparing the doped sulfoxide-type activated carbon adsorbent material with sulfur-containing functional groups according to claim 2, characterized in that: The particle size of the crushed carbon-rich precursor is 50μm~5mm.

5. The method for preparing the doped sulfoxide-type activated carbon adsorbent material with sulfur-containing functional groups according to claim 1, characterized in that: The prepared sulfoxide-doped activated carbon adsorbent material containing sulfur functional groups was stored in a drying device.

6. The method for preparing the doped sulfoxide-type activated carbon adsorbent material with sulfur-containing functional groups according to claim 1, characterized in that: The method for rapidly cooling sulfur-doped activated carbon is to stop heating the reaction system and then rapidly cool it under an inert atmosphere and with the help of an external cold source.

7. A sulfoxide-doped activated carbon adsorbent material containing sulfur functional groups, characterized in that: It is prepared by any one of the preparation methods described in claims 1-6.

8. The application of the sulfoxide-doped activated carbon adsorbent material with sulfur-containing functional groups as described in claim 7 in the removal of SO2 from flue gas.

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