Nitrogen-modified carbon-based material and preparation method thereof

Abstract

The invention discloses a nitrogen-modified carbon-based material and a preparation method thereof, ammonia water is adopted to modify a carbon material, and the adsorption quantity of ammonium ions is accurately regulated and controlled in the modification process, so that the nitrogen-modified carbon-based material with stable quality and performance is directionally obtained, and stable adsorption and removal of hydrogen sulfide can be realized. Besides, a nitrogen-containing additive is added in the burdening stage, so that the nitrogen element and carbon can react in the high-temperature heat treatment process to form abundant surface functional groups, and the adsorption performance on hydrogen sulfide is improved; the whole technological process is short and easy to control, and industrial popularization and application are easy.

Description

Technical Field

[0001] The present invention relates to the modification of carbon-based materials, in particular to a nitrogen-modified carbon-based material and a preparation method thereof, belonging to the technical field of carbon-based material modification. Background Art

[0002] Hydrogen sulfide is an irritating gas with a strong rotten egg odor. It is a potent neurotoxin and a direct threat to human health. Its odor pollution is considered one of the six major public health hazards, second only to noise. Furthermore, hydrogen sulfide can poison catalysts, leading to increased production costs and reduced product quality. It is also a major contributor to air pollution, the greenhouse effect, and ozone depletion. Therefore, improvements in hydrogen sulfide gas treatment technologies and the development of new technologies are urgent challenges in air pollution control.

[0003] The treatment of hydrogen sulfide includes absorption, adsorption, oxidation, decomposition and microbial methods. Among the many methods, the carbon-based material adsorption method has become a popular means of treating hydrogen sulfide gas because carbon-based materials have a high specific surface area and a rich pore structure, and have a good adsorption and removal effect on hydrogen sulfide gas. Currently, the carbon-based adsorption materials on the market mainly use raw coal as the raw material for production. They must go through grinding, molding, carbonization, activation, impregnation, drying and other processes in sequence. The production cost is relatively high, and the impregnation process is usually relatively extensive, resulting in difficult to control product performance, which seriously affects its stability in treating hydrogen sulfide gas.

[0004] In the purification process of industrial waste gas and waste water, a large amount of desulfurization and denitrification waste carbon powder or VOCs adsorption waste carbon powder will be generated. Due to the poor ball-forming properties of these waste carbon powders, they can often only be added to the raw coal in small amounts to replace part of the raw coal for pelletizing. The utilization efficiency of the carbon powder is low, and most of the carbon powder is still used as fuel or directly incinerated, and its utilization value is relatively low. Moreover, in the carbon-based adsorption material obtained by adding a small amount of carbon powder, due to the large proportion of raw coal, its desulfurization performance is not significantly improved compared with the all-raw coal-based adsorption material. If the carbon powder is pelletized independently, a large amount of binder needs to be added, which is costly and the desulfurization performance of the obtained carbon-based adsorption material is relatively low due to the high proportion of binder. Summary of the Invention

[0005] To address the poor stability of existing carbon-based adsorption materials in hydrogen sulfide adsorption and removal, the present invention provides a nitrogen-modified carbon-based material and a method for preparing the same. By modifying the carbon material with ammonia and precisely controlling the amount of ammonium ion adsorption during the modification process, a nitrogen-modified carbon-based material with stable quality and performance is obtained, enabling stable adsorption and removal of hydrogen sulfide. Furthermore, the addition of nitrogen-containing additives during the batching stage facilitates the reaction of nitrogen with carbon during high-temperature heat treatment to form abundant surface functional groups, thereby improving hydrogen sulfide adsorption performance. The entire process of the present invention is short and easy to control, making it amenable to industrial promotion and application.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0007] According to a first embodiment of the present invention, a method for preparing a nitrogen-modified carbon-based material is provided:

[0008] A method for preparing a nitrogen-modified carbon-based material, the method comprising:

[0009] 1) The carbon-based raw materials, nitrogen-containing additives, binders, and water are kneaded into a mixture and then heat-treated to obtain a crude carbon material.

[0010] 2) The crude carbon material is placed in an ammonia solution for impregnation treatment. During the impregnation treatment, the duration of the impregnation treatment is adjusted according to the physical state of the crude carbon material and the ammonia solution to obtain a carbon-based material with an ammonium ion adsorption amount that meets the working condition requirements.

[0011] Preferably, the duration of the impregnation treatment is controlled according to the physical state of the crude carbon material and the ammonia solution during the impregnation treatment process by establishing a control model between the impregnation time and the amount of ammonium ion adsorption in the carbon-based material based on the mass of the crude carbon material, the concentration of the ammonia solution, and the volume of the ammonia solution. The control model is as follows:

[0012] (1).

[0013] In formula (1), Q N Q is the target adsorption amount of ammonium ions in carbon-based materials, ranging from 1 to 3 mg / g. MN It is the maximum adsorption capacity of ammonium ions in carbon-based materials, which needs to be measured and is generally taken as 5~10mg / g. Nis the initial concentration of ammonium ions in the ammonia solution, which needs to be measured, preferably 200~300 mg / L. X is the real-time weight gain rate of the crude carbon material. m is the mass of the crude carbon material, g. v is the volume of the ammonia solution, which needs to be measured, preferably 2~40 L per kilogram of crude carbon material. n0 is the initial mass concentration of the ammonia solution, wt%. n1 is the real-time mass concentration of the ammonia solution during the impregnation process, wt%. a is the impregnation coefficient, which is 0.7~1.3. t is the impregnation time, min. Under given working conditions, the impregnation time corresponding to the target adsorption amount of ammonium ions in the carbon-based material is calculated according to the control model of formula (1).

[0014] Preferably, the carbon-based raw material includes or consists of carbon powder and a binding carbon material. Preferably, the carbon powder is one or more of waste carbon powder from desulfurization and denitrification, waste carbon powder from VOCs adsorption, and waste carbon powder from activated carbon production and transportation. The binding carbon material is asphalt (including coal tar pitch, petroleum pitch, and natural asphalt), coal-to-liquid liquefaction residue, or a mixture thereof.

[0015] Preferably, the amount of the adhesive carbon material is 1-20% of the amount of the carbon powder, preferably 5-15%, more preferably 8-12%.

[0016] Preferably, the particle size of the carbon-based raw material is such that more than 80% passes through 200 mesh or more than 60% passes through 325 mesh, and preferably more than 90% passes through 200 mesh or more than 70% passes through 325 mesh.

[0017] Preferably, the nitrogen-containing additive is one or more of urea, melamine, and ammonium thiocyanate.

[0018] Preferably, the amount of the nitrogen-containing additive is 1 to 18% by mass of the carbon-based raw material, preferably 4 to 16%, and more preferably 6 to 14%.

[0019] Preferably, the binder is one or more of coal tar, carboxymethyl cellulose, polyvinyl alcohol, sesbania powder, starch, and resin.

[0020] Preferably, the amount of the binder is 1-18% by mass of the carbon-based raw material, preferably 3-15%, and more preferably 5-12%.

[0021] Preferably, the particle size of the molding material obtained after kneading and molding is 3 to 15 mm, preferably 5 to 12 mm.

[0022] Preferably, the moisture content of the molding material obtained after kneading and molding is 15-30%, preferably 18-25%.

[0023] Preferably, the shape of the molding material is one of spherical particles, cylindrical particles, rectangular particles, block particles, and honeycomb particles.

[0024] Preferably, the heat treatment is carbonization and / or activation. The carbonization is performed at a temperature of 200-1000°C for 15-180 minutes, preferably at a temperature of 300-900°C for 30-150 minutes. The activation is performed in steam at a temperature of 800-1000°C for 30-1500 minutes, preferably at a temperature of 850-950°C for 60-1200 minutes.

[0025] Preferably, the carbon-based material after the impregnation treatment is dried at a temperature of 50 to 300° C. for a time of 20 to 240 minutes.

[0026] According to a second embodiment of the present invention, there is provided a nitrogen-modified carbon-based material:

[0027] A nitrogen-modified carbon-based material prepared according to the preparation method of the first embodiment. Preferably, the nitrogen-modified carbon-based material contains 0.01% to 0.4% (mass content), more preferably 0.2% to 0.3%, for example, any one of 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, and 0.4%, or a range with any two of these values ​​as endpoints.

[0028] In the present invention, based on a large number of studies on the optimization of carbon-based hydrogen sulfide adsorption material formulas, and the improvement of processes and equipment systems, the present invention further conducted in-depth research and proposed a method for preparing nitrogen-modified carbon-based materials. By combining industrial wastes with high specific surface areas and pore structures, such as desulfurization and denitrification waste carbon powder, VOCs adsorption waste carbon powder, and waste carbon powder generated during the production and transportation of activated carbon, with a certain proportion of adhesive carbon materials, the method is sequentially ground, mixed with nitrogen-containing additives, binders, and water, extruded, heat-treated, cooled, impregnated with ammonia water, dried, cooled, and sieved (the sieved crushed materials can be recycled as carbon-based raw materials for recycling), to obtain high-performance, low-cost, finished granular carbon-based hydrogen sulfide adsorption materials, with significant economic, environmental, and social benefits.

[0029] In the present invention, a carbon-based material with adsorption properties is immersed in a nitrogen-containing ammonia solution, and the nitrogen-containing substance can be adsorbed and stored in the carbon-based material. After that, the nitrogen-containing functional group can be loaded by heat treatment and drying again, which is conducive to the adsorption of hydrogen sulfide gas. After research, it was found that in the process of impregnating and modifying the carbon-based material with ammonia water, when the ammonium ions adsorbed in the carbon-based adsorbent material cause the nitrogen-containing functional groups to be overloaded, the excess nitrogen-containing functional groups will occupy the micropore entrance or the inside of the pore, hindering the diffusion of gas molecules. At the same time, excessive alkalinity will reduce the adsorption efficiency of acidic gases (such as H2S and SO2). Excessive amino groups (-NH2) make the surface strongly alkaline and react quickly with SO2 to form ammonium sulfate salts, but salt deposition blocks the pores and inhibits subsequent reactions. In addition, the carbon skeleton structure on the surface of the over-modified carbon-based adsorbent material becomes fragile, and the wear resistance may decrease. However, if the nitrogen functional group load of the carbon-based adsorption material is too low, it will lead to a low adsorption capacity for polar or acidic gases (such as NOx, H2S), and it will not be possible to achieve an efficient selective reaction for sulfur-containing gases. In other words, a suitable amount of ammonium ion adsorption can ensure that the comprehensive performance of the carbon-based adsorption material is in a better state. Therefore, in the process of placing the crude carbon material in an ammonia solution for impregnation treatment, the present invention regulates the duration of the impregnation treatment according to the physical state of the crude carbon material and the ammonia solution, so as to obtain a carbon-based material whose ammonium ion adsorption amount meets the working condition requirements. Specifically, a control model between the impregnation time and the ammonium ion adsorption amount in the carbon-based material is established based on the mass of the crude carbon material, the concentration of the ammonia solution, the volume of the ammonia solution, etc. The control model is as follows:

[0030] (1).

[0031] In formula (1), Q N Q is the target adsorption amount of ammonium ions in carbon-based materials, ranging from 1 to 3 mg / g. MN C is the maximum adsorption capacity of ammonium ions in carbon-based materials, ranging from 5 to 10 mg / g. N is the initial concentration of ammonium ions in the ammonia solution, which is 200~300 mg / L. X is the real-time weight gain rate of the crude carbon material. m is the mass of the crude carbon material, g (needs to be measured). v is the volume of the ammonia solution, L (preferably 2~40 L per kilogram of crude carbon material). n0 is the initial mass concentration of the ammonia solution, wt% (needs to be measured). n1 is the real-time mass concentration of the ammonia solution during the impregnation process, wt% (needs to be measured). a is the impregnation coefficient, which is 0.7~1.3. t is the impregnation time, min. Under given working conditions, the impregnation time corresponding to the target adsorption amount of ammonium ions in the carbon-based material is calculated according to the control model of formula (1), thereby ensuring that the loading amount of nitrogen-containing functional groups in the obtained carbon-based material is basically consistent, so that the adsorption performance of the obtained carbon-based material for hydrogen sulfide tends to be consistent, that is, a carbon-based material product with relatively stable hydrogen sulfide adsorption and removal performance is obtained.

[0032] It should be noted that all formulas in the present invention are obtained by fitting by the inventors based on experiments and engineering applications, and all calculations are numerical values ​​converted according to prescribed units, and are obtained by substituting the converted numerical values ​​into the formulas (after converting the units, only the numerical values ​​are substituted into the formulas for calculation, without substituting the units; the units are only used to adjust the size of the numerical values).

[0033] In the present invention, it is found through research that the desulfurization and denitrification waste carbon powder or VOCs adsorption waste carbon powder has undergone multiple pollutant adsorption and thermal regeneration, that is, it has undergone multiple high temperature and acidic environment cycle treatments, resulting in the number of functional groups and specific surface area inside the activated carbon being enhanced. The corresponding waste activated carbon powder produced has surface functional groups and pore structure characteristics that are more superior than fresh carbon-based materials, and thus the adsorption catalytic performance is enhanced. In other words, the waste carbon powder already has a certain effect of adsorbing hydrogen sulfide gas because it contains a more developed pore structure, a larger specific surface area and a rich variety of surface functional groups. Therefore, using desulfurization and denitrification waste carbon powder or VOCs adsorption waste carbon powder as the main component of the carbon-based raw material can significantly reduce the raw material cost and turn waste into treasure compared to directly using raw coal as raw material. On the other hand, it can also make the resulting carbon-based adsorption material relatively have better morphological characteristics, and thus have better adsorption catalytic performance.

[0034] In the present invention, research has found that by adding a certain amount of adhesive carbon material (such as asphalt and / or coal-to-liquid liquefaction residue) to waste carbon powder and mixing and grinding, a carbon-based raw material with good ball-forming properties can be obtained. That is, the ball-forming properties of the waste carbon powder can be significantly improved by utilizing the wrapping and adhesion properties of the adhesive carbon material. Moreover, since the adhesive carbon material itself contains a large amount of carbon element, it can also reduce the proportion of non-carbon elements compared to ordinary binders, thereby ensuring the strength of the carbon-based material and the uniform distribution of micro- and fine pores during the subsequent heat treatment process, thereby obtaining a carbon-based adsorption material with excellent adsorption properties. Using too much or too little adhesive carbon material is not conducive to forming a carbon-based adsorption material with the required morphological characteristics. When the amount of adhesive carbon material is too low, the proportion of waste carbon powder in the mixture formed by it and waste carbon powder is too high, which leads to low ball-forming properties of the mixture. It is difficult to directly mix and knead the mixture into a shape, or the strength of the resulting molding material after forced molding is low, and it is easy to explode during heat treatment. Therefore, it is necessary to increase the amount of non-carbon binder used, which increases the cost and makes it difficult to obtain a larger proportion of micro- and fine pores after heat treatment. When the amount of adhesive carbon material is too high, the proportion of waste carbon powder with better surface functional groups and pore structure characteristics will decrease, while the proportion of ordinary carbon elements will increase, which is not conducive to subsequent molding and granulation, nor is it conducive to ensuring the adsorption performance of the subsequent finished carbon-based adsorption material.

[0035] In the present invention, the mixing of carbon-based raw materials, nitrogen-containing additives, adhesives, water, etc. is carried out using a powerful mixing device, such as a powerful mixer, which is a vertical, horizontal or inclined powerful mixer with stirring blades. The mixing effect and continuity of the powerful mixer are better than those of existing intermittent mixing equipment and roller stirring and kneading equipment, and the distribution of the mixed material components is more uniform. That is, the stirring and kneading of the kneading equipment can achieve a more uniform mixing of the solid carbon-based raw materials, adhesives, nitrogen-containing additives and liquid water, further ensuring the stability of product performance.

[0036] It should be noted that nitrogen-containing additives such as urea, melamine, or ammonium thiocyanate, etc., due to their fine particle size, can be directly added in proportion during the mixing stage of the ingredients, and then during the subsequent heat treatment, they can promote the uniform distribution of nitrogen-containing functional groups inside and outside the carbon-based material, thereby enhancing the hydrogen sulfide adsorption performance of the carbon-based material.

[0037] In the present invention, according to the purpose of the carbon-based adsorption material, the kneaded material is pressurized to form a carbon-based molding material of a certain shape. The molding material of a certain shape mentioned here refers to the appearance of the molding material, which can be spherical, cylindrical, block, honeycomb, etc., preferably cylindrical. For example, the size of the cylindrical molding material is generally 3~15mm (preferably 5~12mm). It should be noted that if the moisture content of the molding material is high (greater than 20%), the overall size is relatively soft, which will affect the porosity and strength of the activated carbon during the carbonization process, so that the performance of the carbon-based material does not meet the requirements. Generally, it is necessary to dry it to a certain strength and a certain content of moisture before heat treatment. For example, after the kneading molding process, the molding material needs to be further dried at 50~90℃ (preferably 60~80℃) to a moisture content of less than 10%, preferably less than 8%.

[0038] In the present invention, the molding material is subjected to high-temperature heat treatment to achieve a melt-condensation reaction between waste carbon powder and a bonding carbon material at high temperature, forming a carbon-based material with a certain strength and a certain pore structure. It should be noted that the heat treatment process can be carbonization alone or a combination of carbonization and activation. If carbonization alone is used, carbonization can be performed in a rotary carbonization furnace or a horizontal, translational, and electric-heating furnace. The carbonization temperature is controlled to be between 200°C and 1000°C, the final carbonization temperature is between 600°C and 900°C (preferably between 650°C and 800°C), and the carbonization time is between 15 and 180 minutes. If carbonization combined with activation is used, carbonization can be performed in a rotary carbonization furnace or a horizontal, translational, and electric-heating furnace. The carbonization temperature is controlled to be between 200°C and 900°C, the final carbonization temperature is controlled to be between 600°C and 850°C, and the carbonization time is between 15 and 180 minutes. Activation can be performed in a vertical, Slep furnace or a horizontal, translational, and electric-heating furnace. The activation process controls the activation temperature to be 800-1000° C. (preferably 850-950° C.), the activation time to be 30-1500 min. (preferably 60-1200 min), and the activation medium to be water vapor.

[0039] In the present invention, practical research has found that the modified nitrogen content of the nitrogen-modified carbon-based material obtained after modification and drying (modified nitrogen mainly comes from nitrogen-containing additives and ammonium ions, as the carbon-based material already contains certain nitrogen-containing functional groups or nitrates and nitrites before modification) is preferably controlled between 0.2% and 0.3% (mass content) for best results. Generally, the introduction of excessive nitrogen may cause the micropores or mesopores of the carbon-based material to be occupied by nitrogen-containing functional groups, reducing the effective adsorption space. If the amount of nitrogen introduced is insufficient, the increase in basic functional groups is limited, and the adsorption enhancement effect on acidic gases (such as NOx and hydrogen sulfide) may not be significant.

[0040] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0041] 1: The present invention uses an ammonia solution to impregnate and modify the carbon-based material, thereby significantly improving the adsorption and removal performance of the carbon-based material for hydrogen sulfide. At the same time, the impregnation modification process is precisely controlled, thereby directionally regulating the content of nitrogen-containing functional groups introduced into the carbon-based material, effectively enhancing the surface adsorption sites of the carbon-based material, improving the sulfur selectivity and adsorption of the carbon-based material, and ensuring the stability of the comprehensive performance of the carbon-based material.

[0042] 2: The present invention uses waste carbon powder and adhesive carbon materials with high specific surface area and pore structure as carbon-based raw materials. On the one hand, it can effectively improve the adsorption performance of the finished carbon-based material. On the other hand, it significantly improves the ball-forming property of the waste carbon powder, increases the utilization value of the waste carbon powder, turns waste into treasure, and greatly reduces production costs.

[0043] 3: The overall process flow of the present invention is simple, the obtained carbon-based material has excellent and stable adsorption performance for hydrogen sulfide, the waste carbon powder has high efficiency and benefit, it is easy to realize process application, and has significant economic, environmental and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The figure is a simplified process flow diagram of the preparation method of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0046] Example 1

[0047] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0048] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.80kg of crude carbon.

[0049] 52.80 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 119 min (the real-time weight gain rate X of the crude carbon material is about 51.86%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.71%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.96 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.30% modified nitrogen).

[0050] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 64.6%.

[0051] Example 2

[0052] 60 kg of desulfurization and denitrification waste carbon powder and 4 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0053] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (specifically, the activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 51.92kg of crude carbon.

[0054] 51.92 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 123 min (the real-time weight gain rate X of the crude carbon material is about 50.76%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.72%). After testing, the actual adsorption amount of ammonium ions in the obtained target carbon-based material is about 2.68 mg / g. The obtained target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.27% modified nitrogen).

[0055] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 62.5%.

[0056] Example 3

[0057] 62 kg of desulfurization and denitrification waste carbon powder and 2 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0058] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a moisture content of 7% was obtained. The raw moldings were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 51.04kg of crude carbon.

[0059] 51.04 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 125 min (the real-time weight gain rate X of the crude carbon material is about 50.65%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.72%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.65 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.25% modified nitrogen).

[0060] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 60.8%.

[0061] Example 4

[0062] 56 kg of desulfurization and denitrification waste carbon powder and 8 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0063] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (specifically, the activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 53.06kg of crude carbon.

[0064] 53.06 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 121 min (the real-time weight gain rate X of the crude carbon material is about 50.85%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.71%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.68 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.27% modified nitrogen).

[0065] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 62.6%.

[0066] Example 5

[0067] 54 kg of desulfurization and denitrification waste carbon powder and 10 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0068] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 53.24kg of crude carbon.

[0069] 53.24 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 120 min (the real-time weight gain rate X of the crude carbon material is about 50.56%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.73%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.66 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.25% modified nitrogen).

[0070] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 60.7%.

[0071] Example 6

[0072] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0073] The resulting carbon-based raw material was mixed with 1kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.08kg of crude carbon.

[0074] 52.08 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 122 min (the real-time weight gain rate X of the crude carbon material is about 51.13%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.72%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.75 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.25% modified nitrogen).

[0075] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 60.4%.

[0076] Example 7

[0077] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0078] The resulting carbon-based raw material was mixed with 3kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.46kg of crude carbon.

[0079] 52.46 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 122 min (the real-time weight gain rate X of the crude carbon material is about 51.29% and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.71%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.88 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.27% modified nitrogen).

[0080] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 62.5%.

[0081] Example 8

[0082] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0083] The resulting carbon-based raw material was mixed with 7kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 51.75kg of crude carbon.

[0084] 51.75 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 121 min (the real-time weight gain rate X of the crude carbon material is about 51.62%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.72%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.81 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.29% modified nitrogen).

[0085] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 64.1%.

[0086] Example 9

[0087] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0088] The resulting carbon-based raw material was mixed with 9kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 50.60kg of crude carbon material.

[0089] 50.60 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 124 min (the real-time weight gain rate X of the crude carbon material is about 51.23%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.73%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.72 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.30% modified nitrogen).

[0090] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 64.3%.

[0091] Example 10

[0092] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0093] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.80kg of crude carbon.

[0094] 52.80 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 0.5 mg / g, then according to formula (1), it can be deduced that when the impregnation time t is about 10 min, the target carbon-based material can be obtained (at this time, the real-time weight gain rate X of the crude carbon material is about 50.22%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 23.17%). After testing, the actual adsorption amount of ammonium ions in the obtained target carbon-based material is about 1.69 mg / g. The obtained target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.11% modified nitrogen).

[0095] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 45.2%.

[0096] Example 11

[0097] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0098] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.80kg of crude carbon.

[0099] 52.80 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 1 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 33 min (the real-time weight gain rate X of the crude carbon material is about 50.33%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.92%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 1.88 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.14% modified nitrogen).

[0100] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 48.5%.

[0101] Example 12

[0102] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0103] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.80kg of crude carbon.

[0104] 52.80 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 2 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 74 min (the real-time weight gain rate X of the crude carbon material is about 50.45%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.83%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.29 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.22% modified nitrogen).

[0105] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 54.3%.

[0106] Example 13

[0107] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0108] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were then carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 52.80kg of crude carbon.

[0109] 52.80 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 4 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 174 min (the real-time weight gain rate X of the crude carbon material is about 52.85%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.55%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 3.83 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.33% modified nitrogen).

[0110] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 65.2%.

[0111] Example 14

[0112] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0113] The resulting carbon-based raw material was mixed with 5kg of melamine, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a moisture content of 7% was obtained. The raw moldings were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes). The carbonized material was then activated in a vertical Slep furnace (specifically, the carbonized material was activated with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 51.28kg of crude carbon.

[0114] 51.28 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N The target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 122 min (the real-time weight gain rate X of the crude carbon material is about 51.68%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.75%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.82 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.27% modified nitrogen).

[0115] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 62.8%.

[0116] Example 15

[0117] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0118] The resulting carbon-based raw material was mixed with 5kg of urea, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then fed into a molding machine for granulation to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until green pellets with a moisture content of 7% were obtained. The green pellets were fed into a rotary carbonization furnace for carbonization (the specific carbonization temperature was increased from 200°C to 800°C before being discharged from the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then fed into a vertical Slep furnace for activation (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After activation, the material was cooled to obtain approximately 51.35kg of crude carbon.

[0119] 51.35 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N The target adsorption amount of ammonium ions in the carbon-based material is set to Q NIf the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 120 min (the real-time weight gain rate X of the crude carbon material is about 51.62%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.77%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.77 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.27% modified nitrogen).

[0120] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 62.6%.

[0121] Example 16

[0122] Example 1 was repeated, except that the impregnation time t was directly extended to 149 min. At this time, the real-time weight gain rate X of the crude carbon material obtained was approximately 52.24%, and the real-time mass concentration n1 after impregnation with the ammonia solution was approximately 22.62%. After testing, the actual adsorption amount of ammonium ions in the obtained target carbon-based material was approximately 2.97 mg / g. The obtained target carbon-based material was dried at 200°C for 120 min to obtain a nitrogen-modified carbon-based material (containing approximately 0.31% modified nitrogen).

[0123] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 64.8%.

[0124] Example 17

[0125] Example 1 was repeated, except that the impregnation time t was directly shortened to 89 min. The real-time weight gain rate X of the crude carbon material obtained at this time was approximately 51.55%, and the real-time mass concentration n1 after impregnation with the ammonia solution was approximately 22.71%. After testing, the actual adsorption amount of ammonium ions in the obtained target carbon-based material was approximately 2.75 mg / g. The obtained target carbon-based material was dried at 200°C for 120 min to obtain a nitrogen-modified carbon-based material (containing approximately 0.28% modified nitrogen).

[0126] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 63.7%.

[0127] Example 18

[0128] Example 1 was repeated, except that the raw pellets were fed into a rotary carbonization furnace for carbonization treatment (the specific carbonization heating process was to enter the furnace from 200°C, gradually from the low temperature zone to the high temperature zone of 800°C, and then take out of the furnace, and the process time was 45 minutes) to obtain a carbonized material, and the carbonized material was cooled to obtain a crude carbon material. The crude carbon material was subjected to the impregnation modification process as in Example 1 to obtain the target carbon-based material. After testing, the actual adsorption amount of ammonium ions in the obtained target carbon-based material was about 0.86 mg / g. The obtained target carbon-based material was dried at 200°C for 120 minutes to obtain a nitrogen-modified carbon-based material (containing about 0.09% modified nitrogen).

[0129] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 42.6%.

[0130] Comparative Example 1

[0131] 64 kg of desulfurization and denitrification waste carbon powder was added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0132] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until a green pellet with a moisture content of 7% was obtained. The green pellets were carbonized in a rotary carbonization furnace (the specific carbonization temperature was increased from 200°C to 800°C before exiting the furnace, and the process took 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (specifically, the activation process involved reacting the carbonized material with water vapor at 900°C for 240 minutes). After activation, the carbonized material was cooled to obtain approximately 49.28kg of crude carbon.

[0133] 49.28 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material Q MN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q N If the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 115 min (the real-time weight gain rate X of the crude carbon material is about 45.58%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.98%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.08 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.20% modified nitrogen).

[0134] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 53.6%.

[0135] Comparative Example 2

[0136] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0137] The obtained carbon-based raw material, 4kg of starch, and 15kg of water were fed into a vertical intensive mixer for stirring and kneading to obtain a mixture. The mixture was then fed into a molding machine for granulation to obtain cylindrical moldings with a particle size of approximately 10mm. The moldings were dried at 70°C until green pellets with a moisture content of 7% were obtained. The green pellets were fed into a rotary carbonization furnace for carbonization (the specific carbonization heating process was to start from 200°C in the furnace, gradually increase from the low temperature zone to the high temperature zone of 800°C before being discharged from the furnace, and the process time was 45 minutes) to obtain a carbonized material. The carbonized material was then fed into a vertical Slep furnace for activation (the specific activation process was to react the carbonized material with water vapor at 900°C for 240 minutes). After the activation treatment was completed, the material was cooled to obtain approximately 55.00kg of crude carbon material.

[0138] 55.00 kg of crude carbon material was added to 1500 L of ammonia solution (initial mass concentration n0 was 24%) for impregnation modification. Under the current working conditions: the maximum adsorption capacity of ammonium ions in the carbon-based material QMN The initial concentration of ammonium ions in the ammonia solution is 8 mg / g. N is 280 mg / L, and the impregnation coefficient a is 1.15; the target adsorption amount of ammonium ions in the carbon-based material is set to Q N If the target carbon-based material is 3 mg / g, then according to formula (1), the target carbon-based material can be obtained when the impregnation time t is about 105 min (the real-time weight gain rate X of the crude carbon material is about 49.55%, and the real-time mass concentration n1 after impregnation with ammonia solution is about 22.85%). After testing, the actual adsorption amount of ammonium ions in the target carbon-based material is about 2.35 mg / g. The target carbon-based material is dried at 200 ° C for 120 min to obtain a nitrogen-modified carbon-based material (containing about 0.18% modified nitrogen).

[0139] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3 The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 53.3%.

[0140] Comparative Example 3

[0141] 58 kg of desulfurization and denitrification waste carbon powder and 6 kg of natural asphalt were added to a mixer and ground until more than 80% of the carbon-based raw materials passed 325 mesh.

[0142] The resulting carbon-based raw material was mixed with 5kg of ammonium thiocyanate, 4kg of starch, and 15kg of water in a vertical intensive mixer for mixing and kneading to obtain a mixture. The mixture was then pelletized in a molding machine to obtain cylindrical pellets with a particle size of approximately 10mm. The pellets were then dried at 70°C until they had a moisture content of 7%. The green pellets were then carbonized in a rotary carbonization furnace (the carbonization temperature was increased from 200°C to 800°C before exiting the furnace over a period of 45 minutes) to obtain a carbonized material. The carbonized material was then activated in a vertical Slep furnace (the activation process involved reacting the carbonized material with steam at 900°C for 240 minutes). After activation and cooling, 52.80kg of nitrogen-modified carbon-based material (containing approximately 0.05% modified nitrogen) was obtained.

[0143] The nitrogen-modified carbon-based material prepared above has a hydrogen sulfide content of about 50 mg / m 3The blast furnace gas mixed flue gas is desulfurized: the blast furnace gas mixed flue gas is penetrated through a fixed device equipped with nitrogen-modified carbon-based materials for adsorption purification. The nitrogen-modified carbon-based materials adsorb part of the hydrogen sulfide in the flue gas. Finally, it is detected that the desulfurization rate of the nitrogen-modified carbon-based materials is about 40.5%.

[0144] In the present invention, natural asphalt was sourced from Sinopec Jianghan Oilfield (Jianghan Oilfield Branch of Sinopec Corporation). Ammonium thiocyanate was purchased from Jiaozuo Henghua Chemical Co., Ltd. Melamine was purchased from Sichuan Jinxiang Sairui Chemical Co., Ltd. Urea was purchased from Henan Xinlianxin Chemical Group Co., Ltd. Starch was purchased from Foshan Gaofeng Starch Technology Co., Ltd., and ammonia was purchased from Shandong Sanhe Chemical Co., Ltd.

Claims

1. A method for preparing a nitrogen-modified carbon-based material, characterized in that: The preparation method comprises: 1) The carbon-based raw material, nitrogen-containing additive, binder and water are kneaded and then heat-treated to obtain a crude carbon material; 2) The crude carbon material is placed in an ammonia solution for impregnation treatment. During the impregnation treatment, the duration of the impregnation treatment is adjusted according to the physical state of the crude carbon material and the ammonia solution to obtain a carbon-based material with an ammonium ion adsorption amount that meets the working condition requirements.

2. The preparation method according to claim 1, wherein: The duration of the impregnation treatment is specifically controlled according to the physical states of the crude carbon material and the ammonia solution during the impregnation treatment process: a control model between the impregnation duration and the amount of ammonium ions adsorbed in the carbon-based material is established based on the mass of the crude carbon material, the concentration of the ammonia solution, and the volume of the ammonia solution. The control model is as follows: （1）； In formula (1), Q N is the target adsorption amount of ammonium ions in carbon-based materials, ranging from 1 to 3 mg / g; Q MN is the maximum adsorption capacity of ammonium ions in carbon-based materials, mg / g; C N is the initial concentration of ammonium ions in the ammonia solution, mg / L; X is the real-time weight gain rate of the crude carbon material; m is the mass of the crude carbon material, g; v is the volume of the ammonia solution, L; n0 is the initial mass concentration of the ammonia solution, wt%; n1 is the real-time mass concentration of the ammonia solution during the impregnation process, wt%; a is the impregnation coefficient, which ranges from 0.7 to 1.3; t is the impregnation time, min; under given working conditions, the impregnation time corresponding to the target adsorption amount of ammonium ions in the carbon-based material is calculated according to the control model of formula (1).

3. The preparation method according to claim 1 or 2, characterized in that: The carbon-based raw material includes or consists of carbon powder and a bonding carbon material; preferably, the carbon powder is one or more of waste carbon powder from desulfurization and denitrification, waste carbon powder from VOCs adsorption, and waste carbon powder from activated carbon production and transportation; the bonding carbon material is asphalt, coal-to-liquid liquefaction residue, or a mixture of the two; Preferably, the amount of the adhesive carbon material is 1-20% of the amount of the carbon powder, preferably 5-15%, more preferably 8-12%.

4. The preparation method according to claim 3, wherein: The particle size of the carbon-based raw material is 80% or more passing through 200 mesh or 60% or more passing through 325 mesh, preferably 90% or more passing through 200 mesh or 70% or more passing through 325 mesh.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The nitrogen-containing additive is one or more of urea, melamine, and ammonium thiocyanate; Preferably, the amount of the nitrogen-containing additive is 1 to 18% by mass of the carbon-based raw material, preferably 4 to 16%, and more preferably 6 to 14%.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The binder is one or more of coal tar, carboxymethyl cellulose, polyvinyl alcohol, sesbania powder, starch, and resin; Preferably, the amount of the binder is 1-18% by mass of the carbon-based raw material, preferably 3-15%, and more preferably 5-12%.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The particle size of the molding material obtained after kneading and molding is 3 to 15 mm, preferably 5 to 12 mm; and / or The moisture content of the molding material obtained after kneading and molding is 15-30%, preferably 18-25%; Preferably, the shape of the molding material is one of spherical particles, cylindrical particles, rectangular particles, block particles, and honeycomb particles.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The heat treatment is carbonization and / or activation; wherein: the carbonization is carbonization at a temperature of 200-1000°C for 15-180 minutes, preferably carbonization at a temperature of 300-900°C for 30-150 minutes; the activation is activation in water vapor at a temperature of 800-1000°C for 30-1500 minutes, preferably activation in water vapor at a temperature of 850-950°C for 60-1200 minutes.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The carbon-based material after the impregnation treatment is dried at a temperature of 50 to 300° C. and for a time of 20 to 240 minutes.

10. A nitrogen-modified carbon-based material, characterized in that: The nitrogen-modified carbon-based material is prepared according to the preparation method according to any one of claims 1 to 9; preferably, the nitrogen-modified carbon-based material contains 0.01 to 0.4% modified nitrogen, preferably 0.2 to 0.3%.

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