A system for preparing high specific surface activated carbon from coal gasification ash

Abstract

The utility model discloses a system for coal gasification ash preparation high specific surface activated carbon, including first cyclone separator, second cyclone separator, high gradient magnetic separator, plasma auxiliary dryer, pickling reactor, fixed bed reactor, tubular heating furnace, drying device, carbon dioxide high temperature modification device and microwave auxiliary activation device. The utility model discloses through electromagnetic field even heating raw materials, shortens the activation time, reduces energy consumption simultaneously, and drying is carried out to gasification slag with plasma auxiliary dryer, realizes low -temperature high -efficient drying, in -situ activation pretreatment, synchronous management of pollutant. The utility model discloses gasification ash pickling, carbonization activation, CO2 high temperature modification and microwave auxiliary processing can form the abundant micropore, the mesopore structure, promote the activation efficiency and the specific surface area, make it become the main adsorbent in the treatment dye wastewater, realizes the gasification ash's reduction, the resource, the harmless utilization.

Description

Technical Field

[0001] This utility model relates to the field of industrial solid waste resource utilization and environmental protection technology, and in particular to a system for preparing high specific surface area activated carbon from coal gasification ash residue. Background Technology

[0002] Coal gasification ash is a solid waste generated during the gasification process of coal in a gasifier, containing components and compounds such as residual carbon, SiO2, Al2O3, CaO, MgO, and Fe2O3. Coal gasification is a core technology for the clean and efficient utilization of coal. With the continuous development of coal gasification technology, the production of coal gasification ash is also increasing. Large-scale accumulation not only causes dust pollution and air pollution but also occupies a large amount of land resources, resulting in environmental pollution and ecological damage, and wasting valuable carbon resources. Therefore, in order to accelerate the reduction of carbon emissions and achieve the "dual carbon" goal, the resource utilization of ash is receiving increasing attention. Activated carbon is a type of carbon with a graphite microcrystalline structure, well-developed internal pore structure, and high specific surface area. It has good electrical conductivity and chemical stability, large adsorption capacity, and is insoluble in most solvents, making it promising for applications in gas separation and catalytic reactions. Coal gasification ash, due to its high carbon content and potentially tunable pore structure, has the potential to be used to prepare activated carbon; however, its impurities (such as metal oxides) require targeted treatment. In existing technologies, the pretreatment of ash residue is insufficient, resulting in low carbonization and activation efficiency, high energy consumption, and inadequate equipment integration, making continuous production difficult. Therefore, it is necessary to develop a low-energy-consumption, low-cost, high-activation-efficiency system for preparing high specific surface area activated carbon from coal gasification ash residue that can be used for continuous production. Summary of the Invention

[0003] To address the aforementioned shortcomings of the existing technology, this utility model provides a system for preparing high specific surface area activated carbon from coal gasification ash.

[0004] To achieve the aforementioned objectives, the technical solution adopted by this utility model is as follows:

[0005] A system for preparing high specific surface area activated carbon from coal gasification ash is provided, comprising a cyclone separator, a high-gradient magnetic separator, a plasma-assisted dryer, an acid washing reactor, a fixed-bed reactor, a tubular furnace, a drying device, a carbon dioxide high-temperature modification device, and a microwave-assisted activation device. The cyclone separator separates coal gasification ash A into large-particle gasification slag C, medium-particle gasification slag D, and small-particle gasification slag E. The high-gradient magnetic separator removes magnetic oxides from the large-particle gasification slag C, medium-particle gasification slag D, and small-particle gasification slag E. The plasma-assisted dryer dries the large-particle gasification slag C, medium-particle gasification slag D, and small-particle gasification slag E to obtain different... The process involves: granular gasification ash G; physicochemical property testing H of different granular gasification ash G to obtain a specific granular ash I; an acid washing reactor for acid washing and deashing of the specific granular ash I to obtain acid washing product K; a fixed-bed reactor for carbonizing the acid washing product K to obtain gasification slag; a tubular heater for mixing the gasification slag with an alkaline activator M and then activating it to obtain mixture O; filtering and washing mixture O to obtain filter residue P; a drying device for drying filter residue P to obtain dried material Q; a high-temperature carbon dioxide modification device for carbon gasification reaction and pore expansion of dried material Q to obtain modified material R; and a microwave-assisted activation device for activating modified material R to obtain activated carbon T.

[0006] Furthermore, material transfer and conveying can be achieved by conveyor belts or screw conveyors between the first cyclone separator and the second cyclone separator, between the second cyclone separator and the high gradient magnetic separator, between the high gradient magnetic separator and the plasma-assisted dryer, between the plasma-assisted dryer and the pickling reactor, between the pickling reactor and the fixed bed reactor, between the fixed bed reactor and the tubular furnace, between the tubular furnace and the drying device, between the drying device and the carbon dioxide high-temperature modification device, and between the carbon dioxide high-temperature modification device and the microwave-assisted activation device.

[0007] Furthermore, the cyclone separator includes a first cyclone separator and a second cyclone separator. The first cyclone separator is used to separate coal gasification ash A into large-particle gasification slag C and medium- and small-particle gasification slag B. The second cyclone separator is used to separate medium- and small-particle gasification slag B into medium-particle gasification slag D and small-particle gasification slag E.

[0008] The beneficial effects of this utility model are as follows:

[0009] This invention uses a cyclone separator to separate the gasification slag into particle sizes, thereby homogenizing the particle size and avoiding uneven activation caused by particle size differences.

[0010] This invention utilizes a high-gradient magnetic separator to separate magnetic oxides, which not only significantly improves the performance of the subsequently prepared activated carbon, but also achieves efficient resource recovery and enhances environmental benefits.

[0011] This invention utilizes a plasma-assisted dryer to dry gasification slag, achieving low-temperature, high-efficiency drying, in-situ activation pretreatment, and simultaneous pollutant treatment. This technology not only significantly improves the quality of activated carbon products but also brings substantial environmental and economic benefits through energy conservation, emission reduction, and pollution mitigation. It represents a cutting-edge breakthrough technology in the resource utilization of coal gasification solid waste and has broad prospects for industrialization.

[0012] This invention involves sieving the coal gasification ash residue by particle size and then acid washing it with HF / HCl solution, which greatly reduces the inorganic mineral content in the gasification ash residue.

[0013] The carbonization and activation process of this invention is controllable; the CO2 high-temperature modification technology expands pores through carbon gasification reaction, significantly increasing the proportion of mesopores; microwave-assisted activation uses electromagnetic fields to uniformly heat the raw materials, shortening the activation time and reducing energy consumption. Ultimately, this makes it the main adsorbent for treating dye wastewater, achieving the effect of "treating waste with waste," and realizing the reduction, resource recovery, and harmless utilization of gasification ash.

[0014] This invention has the following advantages: First, the coal gasification ash residue is sieved using a cyclone separator to achieve particle size uniformity, avoiding uneven activation caused by particle size differences. The separation of magnetic oxides using a high-gradient magnetic separator not only significantly improves the performance of the subsequently prepared activated carbon but also achieves efficient resource recovery and enhances environmental benefits. The gasification residue is dried using a plasma-assisted dryer, achieving low-temperature, high-efficiency drying, in-situ activation pretreatment, and simultaneous pollutant treatment. This technology not only significantly improves the quality of activated carbon products but also brings significant environmental and economic benefits through energy conservation, emission reduction, and pollution reduction. It is a cutting-edge breakthrough technology in the field of coal gasification solid waste resource utilization and has broad industrialization prospects. Second, acid washing, carbonization activation, CO2 high-temperature modification, and microwave-assisted treatment of the gasification residue can change its internal structure, forming a rich microporous and mesoporous structure, significantly improving activation efficiency and specific surface area, making it a major adsorbent for treating dye wastewater, thereby achieving the effect of "treating waste with waste" and realizing the reduction, resource recovery, and harmless utilization of gasification ash residue. Finally, due to its simple operation, low energy consumption, low cost, and high activation efficiency, it can achieve continuous production. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the system for preparing high specific surface area activated carbon from coal gasification ash of this utility model;

[0016] Figure 2 These are the adsorption / desorption isotherms of activated carbon at different activation temperatures in the preparation process of this utility model.

[0017] The symbols for the main components in the diagram are explained below:

[0018] 1. Conveyor belt; 2. First cyclone separator; 3. Second cyclone separator; 4. High gradient magnetic separator; 5. Plasma-assisted dryer; 6. Pickling reactor; 7. Fixed bed reactor; 8. Tubular furnace; 9. Drying device; 10. High-temperature carbon dioxide modification device; 11. Microwave-assisted activation device. Detailed Implementation

[0019] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0020] like Figure 1As shown, the system for preparing high specific surface area activated carbon from coal gasification ash includes a first cyclone separator 2, a second cyclone separator 3, a high-gradient magnetic separator 4, a plasma-assisted dryer 5, an acid washing reactor 6, a fixed-bed reactor 7, a tubular furnace 8, a drying device 9, a carbon dioxide high-temperature modification device 10, and a microwave-assisted activation device 11. Material transfer between the first cyclone separator 2 and the second cyclone separator 3, between the second cyclone separator 3 and the high-gradient magnetic separator 4, between the high-gradient magnetic separator 4 and the plasma-assisted dryer 5, between the plasma-assisted dryer 5 and the acid washing reactor 6, between the acid washing reactor 6 and the fixed-bed reactor 7, between the fixed-bed reactor 7 and the tubular furnace 8, between the tubular furnace 8 and the drying device 9, between the drying device 9 and the carbon dioxide high-temperature modification device 10, and between the carbon dioxide high-temperature modification device 10 and the microwave-assisted activation device 11 can be achieved using conveyor belts 1 or screw conveyors. The first cyclone separator 2 is used to separate coal gasification ash A into large-particle gasification slag C and medium-to-small-particle gasification slag B. The second cyclone separator 3 is used to separate the small-to-medium particle size gasification slag B into medium-sized gasification slag D and small-sized gasification slag E. The high-gradient magnetic separator 4 is used to remove magnetic oxides from the large-sized gasification slag C, medium-sized gasification slag D, and small-sized gasification slag E. The plasma-assisted dryer 5 is used to dry the large-sized gasification slag C, medium-sized gasification slag D, and small-sized gasification slag E to obtain gasification ash slag G of different particle sizes. The physicochemical properties of the different particle sizes of gasification ash slag G are then tested (H) to obtain a specific particle size ash slag I. The acid washing reactor 6 is used to acid wash and deash the specific particle size ash slag I to obtain acid washing product K. The fixed-bed reactor 7 is used to carbonize the acid washing product K to obtain gasification slag. The tubular heater 8 is used to mix the gasification slag with an alkaline activator M and then activate the mixture to obtain mixture O. The mixture O is then filtered and washed to obtain filter residue P. The drying device 9 is used to dry the filter residue P to obtain dried product Q. The carbon dioxide high-temperature modification device 10 is used to perform a carbon gasification reaction to expand the pores of dried material Q to obtain modified material R. The microwave-assisted activation device 11 is used to activate the modified material R to obtain activated carbon T.

[0021] The process for preparing high specific surface area activated carbon from coal gasification ash includes the following steps:

[0022] S1. The coal gasification ash residue A is fed into the first cyclone separator 2 through the conveyor belt 1 to separate large-particle gasification residue C and medium- and small-particle gasification residue B.

[0023] S2. The medium and small-sized gasification slag B separated from S1 is fed into the second cyclone separator 3 via conveyor belt 1 to separate medium-sized gasification slag D and small-sized gasification slag E.

[0024] S3. Large-particle gasification slag C, medium-particle gasification slag D and small-particle gasification slag E are fed into high-gradient magnetic separator 4 via conveyor belt 1. Magnetic material F is obtained by separating magnetic oxides through high-gradient magnetic separator 4 and then output via conveyor belt 1.

[0025] S4. The large-particle gasification slag C, medium-particle gasification slag D, and small-particle gasification slag E, from which magnetic oxides have been removed in S3, are dried by plasma-assisted dryer 5 to reduce the moisture content of the large-particle gasification slag C, medium-particle gasification slag D, and small-particle gasification slag E to below 1%. After drying, gasification ash slag G of different particle sizes is obtained.

[0026] S5. The physicochemical properties of gasification ash G of different particle sizes are tested to obtain a certain particle size ash I. Through the physicochemical properties test H, the process is optimized to have a certain particle size ash with higher carbon content, larger specific surface area, more developed pore structure and more active sites.

[0027] S6. The ash residue I of a certain particle size obtained in S5 is acid-washed and deashed in acid washing reactor 6 with HF / HCl solution J. The treated solid is output via conveyor belt 1 to obtain acid washing product K.

[0028] S7. The pickling product K from S6 is carbonized in a fixed-bed reactor 7 under the protection of inert gas L to obtain gasified slag. The carbonization temperature is 400-650 ℃ and the carbonization time is 2 h.

[0029] S8. The gasified slag is fed into the tubular heater 8 for activation, specifically:

[0030] The gasification slag and alkaline activator M were mixed and ground in a ratio of 1:1 to 1:5 to ensure thorough mixing. The mixed sample was then spread evenly in a square ceramic boat. Under nitrogen protection, the ceramic boat was pushed into the activation reaction device 8. The temperature was increased from room temperature to 600-1000 ℃ at a rate of 10 ℃ / min and maintained at this temperature for 2 h for activation treatment. After cooling to room temperature, the sample was ground and soaked in 1 mol / L hydrochloric acid solution N for 12 h to obtain mixture O.

[0031] S9. Filter the mixture O and wash it with distilled water until it is neutral to obtain filter residue P;

[0032] S10. The washed filter residue P is fed into the drying device 9 via conveyor belt 1 and dried at 80 ℃ for 24 h to obtain dried product Q;

[0033] S11. The dried material Q is fed into the carbon dioxide high-temperature modification device 10 via conveyor belt 1. CO2 is introduced at 700-1100 ℃ at a flow rate of 20-80 mL / min for 1-4 h. The pores are expanded by carbon gasification reaction, and the proportion of mesopores is significantly increased to obtain the modified material R.

[0034] S12. The modified material R is fed into the microwave-assisted activation device 11 via the conveyor belt 1 for activation to obtain the activated material S. The activated material S is output via the conveyor belt 1 to obtain activated carbon T.

[0035] After pretreatment such as screening and drying, the coal gasification slag was acid-treated with a 6 mol / L hydrofluoric acid and hydrochloric acid solution to obtain an acid-washed product. This product was then carbonized in a carbonization reactor by introducing inert gas at a flow rate of 1 L / min and raising the temperature to 600 °C at a rate of 10 °C. Next, an alkaline activator and the carbonized product were ground in a mortar at a different ratio (alkaline activator:carbonized product = 4:1) to ensure thorough mixing. The mixed sample was then spread evenly in a square ceramic boat, and an activation reaction device was placed using N2 as a protective gas. The temperature was raised from room temperature to 600 °C at a rate of 10 °C / min and maintained at this temperature for 2 h for activation treatment. After cooling, the sample was ground again, soaked in 1 mol / L hydrochloric acid for 12 h, filtered, and the filter residue was washed with distilled water until the pH reached 7. Finally, the sample was dried at 80 °C for 24 h in a drying apparatus to obtain the specified activated carbon. Activated carbon is named DCS-TX, where X is the proportion of alkaline activator and T is the temperature at which the activated carbon is prepared. For example, DCS-600-4 is activated carbon prepared with KOH:DCS = 4:1 at a temperature of 600 ℃. Following the same process, the specific surface area and pore structure parameters of the activated carbon prepared at activation temperatures of 600 ℃, 700 ℃, 800 ℃, 900 ℃, and 1000 ℃ are obtained, specifically:

[0036] Table 1 shows the specific surface area and pore structure parameters of activated carbon prepared at different activation temperatures.

[0037]

[0038] The specific surface area and pore structure parameters of activated carbon prepared at different activation temperatures are shown in the table, as well as... Figure 2 The adsorption / desorption isotherms of activated carbon at different activation temperatures show that the activated carbon prepared at an activation temperature of 900 ℃ has a specific surface area as high as 960.18 m². 2 / g. Therefore, an activation temperature of 900 ℃ is the optimal condition for preparing high specific surface area activated carbon, which can be used as the main adsorbent for treating dye wastewater, thereby achieving the effect of "treating waste with waste" and realizing the reduction, resource utilization, and harmless use of gasification ash.

Claims

1. A system for preparing high specific surface area activated carbon from coal gasification ash, characterized in that, It includes several cyclone separators, high gradient magnetic separators (4), plasma-assisted dryers (5), pickling reactors (6), fixed-bed reactors (7), tubular furnaces (8), drying devices (9), carbon dioxide high-temperature modification devices (10), and microwave-assisted activation devices (11). The cyclone separator includes a first cyclone separator (2) and a second cyclone separator (3). The first cyclone separator (2) is used to separate coal gasification ash A into large-particle gasification slag C and medium- and small-particle gasification slag B. The second cyclone separator (3) is used to separate medium- and small-particle gasification slag B into medium-particle gasification slag D and small-particle gasification slag E.

2. The system for preparing high specific surface area activated carbon from coal gasification ash residue according to claim 1, characterized in that, Material transfer and conveying can be achieved by conveyor belt (1) or screw conveyor between the first cyclone separator (2) and the second cyclone separator (3), between the second cyclone separator (3) and the high gradient magnetic separator (4), between the high gradient magnetic separator (4) and the plasma-assisted dryer (5), between the plasma-assisted dryer (5) and the pickling reactor (6), between the pickling reactor (6) and the fixed bed reactor (7), between the fixed bed reactor (7) and the tubular heater (8), between the tubular heater (8) and the drying device (9), between the drying device (9) and the carbon dioxide high temperature modification device (10), and between the carbon dioxide high temperature modification device (10) and the microwave-assisted activation device (11).

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