Solid fuel comprehensive modification device and electric power system

Abstract

The utility model belongs to the field of solid fuel modification, and particularly discloses a solid fuel comprehensive modification device and a power system.The solid fuel comprehensive modification device comprises a modification unit, the modification unit comprises at least one washing assembly, and each washing assembly comprises at least one washing box; the washing tank is used for containing solid fuel to be modified and introducing a liquid solvent to form mixed slurry, and non-desulfurized flue gas is introduced into the mixed slurry to achieve comprehensive modification of the solid fuel. On one hand, mineral substances such as alkali metal and alkaline earth metal in the solid fuel can be removed, so that the heat value of the solid fuel is effectively increased, the contamination and slagging tendency in the combustion process is weakened, the emission amount of particulate matter is reduced, and on the other hand, the physical characteristics and chemical characteristics of the solid fuel can be improved; such as a carbon structure, a pore structure, hydrophilicity and hydrophobicity, free radicals and the like, so that subsequent high-value utilization of the solid fuel is facilitated, and comprehensive modification of the solid fuel is realized.

Description

Technical Field

[0001] The present application belongs to the field of solid fuel modification, and more specifically, relates to a solid fuel comprehensive modification device and a power system. Background Art

[0002] Solid fuel modification is a technical approach that alters the chemical structure and physical properties of solid fuels to improve their combustion performance and energy efficiency. Existing technologies primarily modify solid fuels through physical, chemical, or biological methods. However, these methods are limited in functionality and can only meet specific industrial needs, failing to achieve comprehensive modification and quality improvement. Furthermore, existing solid fuel modification devices typically require the addition of additional chemical reagents or complex device designs to improve the modification effect, resulting in high costs and difficulties in industrial application. Utility Model Content

[0003] In response to the defects of the existing technology, the present application provides a solid fuel comprehensive modification device and power system, aiming to solve the problems of high cost and single function of the existing modification devices.

[0004] According to one aspect of the present application, a solid fuel comprehensive modification device is provided, which includes a modification unit, the modification unit includes at least one group of water washing components, each group of the water washing components includes at least one water washing box, the water washing box is used to hold the solid fuel to be modified, the water washing box is provided with a water inlet, an air inlet, an air outlet and a slurry outlet, the water inlet is used to introduce a liquid solvent to form a mixed slurry; the air inlet is used to introduce undesulfurized flue gas; the air outlet is used to discharge the flue gas after the modification reaction; the slurry outlet is used to discharge the modified mixed slurry, thereby realizing comprehensive modification of the solid fuel.

[0005] Compared with the existing technology, the above technical solution conceived by the present application introduces micro-nano bubbles into solid fuel modification, and can achieve physical and chemical modifications while carrying out demineralization treatment in combination with undesulfurized flue gas, thereby achieving comprehensive modification of solid fuel.

[0006] As a further preference, the air inlet is provided with a micro-nano bubble generator for passing the undesulfurized flue gas into the mixed slurry in the form of micro-nano bubbles.

[0007] As a further preferred embodiment, the solid fuel comprehensive modification device also includes a slurry conveying unit and a slurry processing unit. The slurry conveying unit is arranged between the modification unit and the slurry processing unit, and is used to convey the modified mixed slurry into the slurry processing unit; the slurry processing unit is used to perform solid-liquid separation and drying treatment on the modified mixed slurry to obtain modified solid fuel.

[0008] As a further preference, the slurry processing unit includes a solid-liquid separation component and a drying component, one end of the solid-liquid separation component is connected to the slurry conveying unit, and the other end is connected to the drying component, which is used to separate the solid and liquid of the modified mixed slurry and send the separated solid matter into the drying component for drying, thereby obtaining modified solid fuel.

[0009] As a further preference, each group of water washing components in the modification unit is connected in parallel, and each water washing tank in the water washing component is connected in parallel.

[0010] As a further preference, the air inlet is used to be connected to the outlet of the dust collector so as to pass the undesulfurized flue gas into the modification unit.

[0011] According to another aspect of the present application, there is provided an electric power system including the above-mentioned solid fuel comprehensive modification device, the electric power system also including a boiler, a dust collector, a desulfurization tower and a flue gas heat exchanger connected in sequence along the flue gas flow direction, the air inlet of the modification unit is connected to the outlet of the dust collector to feed the undesulfurized flue gas into the modification unit; the air outlet of the modification unit is respectively connected to the inlet of the desulfurization tower and the inlet of the flue gas heat exchanger to feed the flue gas after the modification reaction into the desulfurization tower or the flue gas heat exchanger.

[0012] As a further preference, the outlet of the dust collector is connected to the inlet of the desulfurization tower and the air inlet of the modification unit respectively through a first control valve, so as to adjust the proportion of flue gas entering the modification unit according to the operating conditions of the modification unit; the air outlet of the modification unit is connected to the inlet of the desulfurization tower and the inlet of the flue gas heat exchanger respectively through a second control valve, so as to control the flue gas after the modification reaction to enter the desulfurization tower or the flue gas heat exchanger according to the operating conditions of the modification unit.

[0013] As a further preference, the modification unit further includes a SO2 concentration detection component, which is arranged between the gas outlet and the second control valve to control the flue gas from entering the desulfurization tower or the flue gas heat exchanger according to the SO2 concentration in the flue gas after the modification reaction.

[0014] In general, the above technical solutions conceived by this application have the following technical advantages compared with the existing technology:

[0015] 1. The solid fuel comprehensive modification device provided in this application, by introducing complex, undesulfurized flue gas into a mixed slurry, can achieve comprehensive modification of the solid fuel under the action of complex gas components, including high-concentration SO2, CO2, and HCl. This device does not require complex device design or the introduction of other chemical reagents, yet achieves excellent modification results. It also achieves synergistic flue gas desulfurization, reducing the cost of subsequent flue gas treatment, and has promising industrial application prospects.

[0016] 2. In particular, the present application provides micro-nano bubbles in the modification unit and introduces the undesulfurized flue gas into the mixed slurry containing the solid fuel in the form of micro-nano bubbles. The combined action of the sulfur-containing flue gas and the micro-nano bubbles can, on the one hand, remove minerals such as alkali metals and alkaline earth metals from the solid fuel, thereby effectively improving the calorific value of the solid fuel, reducing the tendency of fouling and slagging during the combustion process, and reducing the emission of particulate matter. On the other hand, the present application can improve the physical and chemical characteristics of the solid fuel, such as carbon structure, pore structure, hydrophilicity, free radicals, etc., thereby facilitating the subsequent high-value utilization of the solid fuel, thereby achieving comprehensive modification of the solid fuel. The present application has the advantages of simple operation, mild conditions, and low cost, and has a relatively broad application prospect.

[0017] 3. Furthermore, this application requires only connecting the air inlet of the modification unit to a dust collector, and the air outlet of the modification unit to a desulfurization tower and flue gas heat exchanger. This allows the solid fuel comprehensive modification device to be applied to existing power systems. This not only requires minimal modification to existing power systems, effectively reducing industrial application costs, but also partially or completely replaces the function of the desulfurization tower, achieving both comprehensive solid fuel modification and flue gas desulfurization, further reducing production costs.

[0018] 4. In addition, the present application can realize intelligent distribution of flue gas through the cooperation of the first control valve, the second control valve and the SO2 concentration detection component, thereby maximizing the flue gas desulfurization effect of the modification unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the solid fuel comprehensive modification device provided in the embodiment of the present application;

[0020] Figure 2 Schematic diagram of the structure of the modification unit in the solid fuel comprehensive modification device provided in the embodiment of the present application;

[0021] Figure 3 Schematic diagram of a power system including a solid fuel comprehensive reforming device provided in an embodiment of the present application;

[0022] Figure 4 The removal rate of minerals in modified coal obtained in Example 1 and Comparative Examples 1 to 3 of the present application;

[0023] Figure 5 The total content of acid-infusible minerals in the modified coal obtained in Example 1 and Comparative Examples 1 to 3 of the present application;

[0024] Figure 6 The microcrystalline structure parameters of the modified coal obtained in Example 1 and Comparative Examples 1 to 3 of the present application, wherein (a) is , (b) is , (c) is , (d) is ;

[0025] Figure 7 The carbon structure parameter changes of the modified coal obtained in Example 1 and Comparative Examples 1 to 3 of the present application;

[0026] Figure 8 The S / N morphological distribution characteristics in the modified coal are obtained in Example 1 and Comparative Examples 1 to 3 of the present application, wherein (a) is the morphological distribution characteristics of the S element in the modified coal, and (b) is the morphological distribution characteristics of the N element in the modified coal.

[0027] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0028] 1-modification unit, 11-water washing box, 12-micro-nano bubble generator, 13-air inlet, 14-air outlet, 15-water inlet, 16-slurry outlet, 17-SO2 concentration detection component, 18-branch gas line, 19-main gas line, 2-slurry conveying unit, 21-slurry conveying pipeline, 22-screw propeller, 3-slurry processing unit, 31-solid-liquid separation component, 32-drying component, 4-boiler, 5-economizer, 6-dust collector, 7-desulfurization tower, 71-first control valve, 72-second control valve, 73-third control valve, 74-fourth control valve, 8-flue gas heat exchanger, 9-chimney. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0030] like Figure 1 、 2 As shown, according to one aspect of the present application, a solid fuel comprehensive modification device is provided, which includes a modification unit 1, wherein: the modification unit 1 includes at least one group of water washing components, each group of water washing components includes at least one water washing box 11, the water washing box 11 is used to hold the solid fuel to be modified and provide a reaction place for its comprehensive modification, the water washing box 11 is provided with a water inlet 15, an air inlet 13, an air outlet 14 and a slurry outlet 16, the water inlet 15 is used to introduce a liquid solvent into the water washing box 11 to form a mixed slurry; the air inlet 13 is used to introduce undesulfurized flue gas into the water washing box 11; the air outlet 14 is used to discharge the flue gas after the modification reaction; the slurry outlet 16 is used to discharge the modified mixed slurry, thereby realizing comprehensive modification of the solid fuel.

[0031] The solid fuel comprehensive modification device provided in this application, by passing undesulfurized flue gas into a mixed slurry, can achieve comprehensive modification of the solid fuel under the action of complex gas components including high concentrations of SO2, CO2, and HCl. This does not require complex device design or the introduction of other chemical reagents to achieve a good modification effect. At the same time, this application utilizes the power plant's own flue gas to perform modification pretreatment on the solid fuel, which is not only simple in process and low in cost, but also can synergistically remove SO2 from the flue gas, effectively improving the overall removal efficiency of SO2 from the flue gas and further reducing the operating costs of the power plant.

[0032] Furthermore, the air inlet 13 is provided with a micro-nano bubble generator 12, which is used to pass the undesulfurized flue gas into the mixed slurry in the form of micro-nano bubbles, so that under the joint action of the multiple free radicals generated by the micro-nano bubbles and the complex flue gas components, the solid fuel is demineralized and the physical and chemical properties of the solid fuel are improved, thereby realizing the comprehensive modification of the solid fuel, effectively solving the problem of single function and poor effect of the modification method in the existing technology.

[0033] In terms of demineralization, this application boasts high demineralization efficiency, effectively increasing the calorific value of solid fuels while reducing fouling and slagging during combustion and reducing particulate matter emissions. During the modification process, the generation of flue gas micro-nanobubbles enhances the solubility of acidic gases in flue gas in water, significantly lowering the pH of the mixed slurry and effectively removing alkali and alkaline earth metals (AAEMs) present in ion-exchange and acid-soluble forms from the solid fuel. Furthermore, the presence of flue gas micro-nanobubbles generates a significant number of ·OH and ·O radicals. These radicals possess greater electronic energy than the ·H radicals provided solely by the acid solution during pickling and modification. These radicals can disrupt Al—O bonds in the aluminosilicate / silicate lattice structure of AAEMs, converting them to Si—O bonds, thereby promoting the transformation of acid-insoluble AAEMs into other forms and improving overall AAEM removal efficiency. This application also simultaneously removes some trace elements from solid fuels, reducing the accumulation of toxic elements and reducing the toxicity of particulate matter. In addition, the present application utilizes the interaction of flue gas acid gases (SO2, CO2, HCl, etc.) with water in the form of micro-nano bubbles, and the formation of mixed acidic solutions such as H2SO3, H2SO4, H2CO3, and HCl, to achieve enhanced and efficient removal of inorganic impurities in solid fuels.

[0034] In terms of physical modification, this application can achieve the following effects:

[0035] (1) Changing the carbon structure: Flue gas micro-nano bubbles will produce strong oxidizing free radicals such as ·OH and ·O in water. These free radicals can effectively destroy the complex organic structure in the solid fuel, destroy the aromatic ring structure in the solid fuel, reduce the aromatization degree of the solid fuel, thereby improving the thermal utilization (pyrolysis, combustion, gasification, etc.) efficiency of the solid fuel, and promote the breakage of the side chains and bridge chains in the solid fuel, reducing the molecular weight of the solid fuel, thereby improving the liquefaction efficiency of the solid fuel.

[0036] (2) Pore modification: Strong oxidizing free radicals such as ·OH and ·O can destroy the complex organic structure in solid fuels, reduce the degree of aromatization and molecular weight, and more effectively open the pores within the solid fuel, forming a porous structure. This can also simultaneously increase the specific surface area of ​​the solid fuel particles, further improving the thermal efficiency of the solid fuel. At the same time, if the solid fuel is subsequently processed into activated carbon, the larger specific surface area and pore structure can effectively increase the adsorption capacity of the activated carbon.

[0037] (3) Hydrophilicity and hydrophobicity: During the continuous generation of flue gas micro-nanobubbles, a large number of ·OH free radicals will be generated. During the reaction with solid fuel, the ·OH free radicals will increase the -OH functional groups in the solid fuel particles, thereby increasing the hydrophilicity of the solid fuel and helping to improve the dispersion and stability of the solid fuel in water. For the preparation of water-coal slurry, the increase in hydrophilicity can reduce the aggregation between coal particles and improve the fluidity of the water-coal slurry, thereby improving its overall performance. At the same time, the increase in the hydrophilicity of coal will also increase the viscosity of coal, making it a high-viscosity coal that can replace coking coal.

[0038] If it is necessary to change the hydrophilicity or hydrophobicity of coal, the flue gas micro-nano bubble generator can be subsequently turned off, and only flue gas components are continuously introduced into the water. The H free radicals and water molecules generated by the O2, SO2 and other gases in the flue gas components dissolving in water can react with the functional groups on the surface of the solid fuel, thereby reducing the content of the -OH functional group and reducing the hydrophilicity of the solid fuel. Some of them will replace the -OH functional groups to generate hydrophobic groups such as linear or branched alkyl hydrocarbons and alkylphenols, and even turn the solid fuel into a hydrophobic solid fuel.

[0039] In terms of chemical modification, sulfur-containing molecular structures such as thiophene / sulfone / sulfoxide and nitrogen-containing molecular structures such as pyridine / pyrrole in coal have high thermal stability. Desulfurization and denitrification require relatively high temperatures. Flue gas micro-nano bubbles produce strong oxidizing free radicals such as ·OH and ·O in water, which can effectively destroy these stable sulfur- and nitrogen-containing organic molecular structures, forming sulfur free radicals such as ·SH and RS· and nitrogen free radicals such as ·NH2, ·NR2, and ·NO2. These free radicals have very low thermal stability and are easier to remove, which can help the subsequent high-value utilization of solid fuels.

[0040] In other aspects, the method provided by the present application can be carried out at room temperature and pressure, with simple operation and mild operating conditions. At the same time, the gas source used in the present application is power plant flue gas, which is low in cost and easy to obtain. If the flue gas also contains a high concentration of Cl or NO x content, the solid fuel modification effect will be further improved.

[0041] In addition, after the flue gas is modified with micro-nano bubbles, the SO2 content in the flue gas will be effectively reduced. If there is a high concentration of Cl or NO in the flue gas, x The content can be reduced during the process of flue gas micro-nano bubble modification. The flue gas then enters the desulfurization tower 7, which can effectively reduce the operating load of the desulfurization tower 7, reduce the amount of desulfurizer used, save costs, and reduce the content of harmful gases discharged into the atmosphere. If multiple solid fuel modification devices are connected in series, they can even replace the function of the desulfurization tower 7. The coal washing wastewater obtained after solid-liquid separation of the modified mixed slurry can be connected to the desulfurization wastewater treatment unit without the need for an additional coal washing wastewater treatment system.

[0042] Furthermore, pure water is the best liquid solvent, and boiler drum water, domestic water or water deeply treated by the desulfurization wastewater treatment system (water treated by reverse osmosis, mechanical steam recompression or multi-effect evaporation of the clean water in the upper part of the clarifier) ​​can also be used, thereby effectively reducing the modification cost.

[0043] Furthermore, the solid fuel comprehensive modification device also includes a slurry conveying unit 2 and a slurry processing unit 3. The slurry conveying unit 2 is arranged between the modification unit 1 and the slurry processing unit 3, and is used to convey the modified mixed slurry into the slurry processing unit 3. The slurry conveying unit 2 includes at least one slurry conveying pipeline 21, one end of which is connected to the slurry outlet 16 of the water washing box 11, and the other end is connected to the slurry processing unit 3. At the same time, a screw propeller 22 is provided inside the slurry conveying pipeline 21 to provide power for the transmission of the mixed slurry.

[0044] The slurry processing unit 3 is used to perform solid-liquid separation and drying treatment on the modified mixed slurry to obtain modified solid fuel. The slurry processing unit 3 includes a solid-liquid separation component 31 and a drying component 32. One end of the solid-liquid separation component 31 is connected to the slurry conveying pipeline 21, and the other end is connected to the drying component 32. It is used to perform solid-liquid separation on the modified mixed slurry and send the separated solid matter into the drying component 32 for drying to obtain modified solid fuel. The heat source of the drying component 32 can come from the flue gas, and the heating and drying function is achieved through heat exchange.

[0045] Furthermore, each group of water washing components in the modification unit 1 is connected in parallel. When there are N groups of water washing components, the modification unit 1 includes a main gas path 19 and N branch gas paths 18, thereby dividing the undesulfurized flue gas into N paths and respectively passing them into each group of water washing components; at the same time, each water washing box 11 in each group of water washing components is connected in parallel, and the air inlet 13 of each water washing box 11 is respectively connected to the branch gas path 18, thereby respectively passing the undesulfurized flue gas in the branch gas path 18 into each water washing box 11. At the same time, the flue gas discharged from the air outlet 14 of each water washing box 11 after the modification reaction is collected and then post-processed. Preferably, the number of water washing components is 3 to 5 groups, and the number of water washing boxes 11 in each group of water washing components is 4 to 8. In actual applications, the appropriate number of water washing components and water washing boxes 11 can be selected according to the flue gas concentration, the characteristics of the solid fuel, and other factors.

[0046] Furthermore, the air inlet 13 is used to connect with the outlet of the dust collector 6 to pass the dust-free and undesulfurized flue gas into the modification unit 1. The flue gas composition is relatively complex, mainly CO2, SO2 and O2, and contains a small amount of escaped NO x , which is beneficial to the comprehensive modification of solid fuels.

[0047] According to another aspect of the present application, Figure 3 As shown, a power system including the above-mentioned solid fuel comprehensive modification device is provided, and the power system also includes a boiler 4, an economizer 5, a dust collector 6, a desulfurization tower 7 and a flue gas heat exchanger 8 connected in sequence along the flue gas flow direction. The air inlet 13 of the modification unit 1 is connected to the outlet of the dust collector 6 to feed the undesulfurized flue gas into the modification unit 1; the air outlet 14 of the modification unit 1 is respectively connected to the inlet of the desulfurization tower 7 and the inlet of the flue gas heat exchanger 8 to feed the flue gas after the modification reaction into the desulfurization tower 7 or the flue gas heat exchanger 8. In actual application, the modification unit 1 can be used to partially replace or completely replace the desulfurization tower 7, so as to achieve the effect of comprehensive modification and synergistic desulfurization of solid fuel.

[0048] Furthermore, the drying component 32 is connected to the outlet of the boiler 4 to utilize the flue gas for heat exchange drying.

[0049] Furthermore, the outlet of the dust collector 6 is connected to the inlet of the desulfurization tower 7 and the air inlet 13 of the reforming unit 1, respectively, via a first control valve 71, to adjust the proportion of flue gas entering the reforming unit 1 according to the operating conditions of the reforming unit 1. The first control valve 71 can adjust the proportion of flue gas entering the reforming unit 1 within a range of 0 to 100%. Generally, 100% of the undesulfurized flue gas can enter the reforming unit 1. Alternatively, an appropriate proportion of undesulfurized flue gas can be sent to the reforming unit 1, and the remaining undesulfurized flue gas can be sent to the desulfurization tower 7, depending on the operating conditions of the reforming unit 1, such as the number of normally operating water wash tanks 11 and the quality of the solid fuel to be reformed. When the reforming unit 1 fails or requires regular shutdown for maintenance, the desulfurization tower 7 can be fully switched to the desulfurization tower 7.

[0050] Preferably, the main gas path 19 in the reforming unit 1 is connected to each branch gas path 18 via a third control valve 73. Simultaneously, each branch gas path 18 is connected to the air inlet 13 of the water wash tank 11 via a fourth control valve 74. Thus, the third and fourth control valves 73 and 74 are used to perform secondary redistribution of the undesulfurized flue gas entering the reforming unit. If a fault occurs in a water wash assembly or a water wash tank 11, the corresponding branch gas path 18 or air inlet 13 can be closed using the third and fourth control valves 73 and 74 to avoid affecting the normal operation of the entire solid fuel reforming device.

[0051] At the same time, the gas outlet 14 of the modification unit 1 is connected to the inlet of the desulfurization tower 7 and the inlet of the flue gas heat exchanger 8 respectively through the second control valve 72, so as to control the flue gas after the modification reaction to enter the desulfurization tower 7 or the flue gas heat exchanger 8 according to the working conditions of the modification unit 1. When the flue gas after the modification reaction meets the national emission standards, it can be directly passed into the flue gas heat exchanger 8 for "whitening" treatment and then discharged through the chimney 9, thereby completely replacing the role of the desulfurization tower 7 with the solid fuel comprehensive modification device; when the flue gas after the modification reaction does not meet the national emission standards, it can be passed into the desulfurization tower 7 for further desulfurization reaction, and then sent to the flue gas heat exchanger 8 after the conditions are met, thereby partially replacing the role of the desulfurization tower 7 with the solid fuel comprehensive modification device, reducing the use of desulfurizers.

[0052] Preferably, the modification unit 1 further includes a SO2 concentration detection component 17, which is disposed between the gas outlet 14 and the second control valve 72 to adjust the SO2 concentration in the flue gas after the modification reaction to control the flue gas to enter the desulfurization tower 7 or the flue gas heat exchanger 8.

[0053] Furthermore, the power system further includes a control device 10 , which is connected to the first control valve 71 , the second control valve 72 , the third control valve 73 and the fourth control valve 74 to perform intelligent distribution and regulation of the flue gas.

[0054] The present application will be further described below with reference to specific embodiments and comparative examples.

[0055] Example 1

[0056] S1 dissolving the coal to be modified in deionized water to obtain a mixed slurry;

[0057] S2 uses 3000ppm SO2+5%O2+15%CO2 mixed with balance gas N2 to simulate undesulfurized flue gas, and introduces it into the mixed slurry in the form of micro-nano bubbles to achieve comprehensive modification of solid fuel;

[0058] S3 performs solid-liquid separation and drying on the modified mixed slurry to obtain modified coal.

[0059] Comparative Example 1

[0060] S1 dissolving the coal to be modified in deionized water to obtain a mixed slurry, and stirring the mixed slurry to achieve comprehensive modification of the solid fuel;

[0061] S2 performs solid-liquid separation and drying on the modified mixed slurry to obtain modified coal.

[0062] Comparative Example 2

[0063] S1 dissolving the coal to be modified in deionized water to obtain a mixed slurry;

[0064] S2 introduces H2SO4 into the mixed slurry. Since the pH of the mixed slurry is stabilized at 2.5 after continuous introduction of undesulfurized flue gas, it is necessary to ensure that the pH of the mixed slurry is stable at 2.5. After a period of reaction, comprehensive modification of the solid fuel is achieved;

[0065] S3 performs solid-liquid separation and drying on the modified mixed slurry to obtain modified coal.

[0066] Comparative Example 3

[0067] S1 dissolving the coal to be modified in deionized water to obtain a mixed slurry;

[0068] S2 uses 3000ppm SO2+5%O2+15%CO2 mixed with balance gas N2 to simulate undesulfurized flue gas and directly introduces it into the mixed slurry to achieve comprehensive modification of solid fuel;

[0069] S3 performs solid-liquid separation and drying on the modified mixed slurry to obtain modified coal.

[0070] The modified coal obtained in Example 1 and Comparative Examples 1 to 3 were tested for demineralization performance, crystal structure, pore structure, surface chemical composition and element content. The results are as follows: Figures 4 to 8As shown in the figure, the flue gas micro-nano bubbles are the modified coal obtained in Example 1, the deionized water is the modified coal obtained in Comparative Example 1, the H2SO4 is the modified coal obtained in Comparative Example 2, and the flue gas is the modified coal obtained in Comparative Example 3.

[0071] (1) Demineralization performance test

[0072] Table 1 shows the content and occurrence forms of inorganic elements in the coal to be modified used in Example 1 and Comparative Examples 1 to 3.

[0073] Table 1 Content and occurrence forms of inorganic elements in the coal to be modified

[0074]

[0075] Figure 2 is the removal rate of minerals in the modified coal obtained in Example 1 and Comparative Examples 1 to 3, Figure 3 is the total content of acid-infusible minerals in the modified coal obtained in Example 1 and Comparative Examples 1 to 3, wherein:

[0076] Removal rate = Na / Ca / Mg / Fe content in modified coal / Na / Ca / Mg / Fe content in raw coal

[0077] Comprehensive removal rate = (Na+Ca+Mg+Fe) content in modified coal / (Na+Ca+Mg+Fe) content in raw coal.

[0078] from Figure 4 It can be seen that compared with deionized water coal washing, acid washing and flue gas coal washing can effectively improve the mineral removal rate in coal. The element removal rate of flue gas coal washing is roughly equivalent to that of H2SO4 coal washing, and flue gas micro-nano bubble coal washing can further improve the mineral removal rate in coal. At the same time, Figure 5 It can be seen that the additional minerals removed are mainly acid-insoluble minerals (mainly silicates and aluminosilicates), which shows that the flue gas micro-nano bubbles can react with acid-insoluble minerals, destroy the lattice structure, promote the transformation of acid-insoluble minerals, and thus improve the mineral removal rate.

[0079] (2) Crystal structure

[0080] The modified coals obtained in Example 1 and Comparative Examples 1 to 3 were subjected to XRD and Raman tests to obtain the structural evolution behavior of the modified coals. The XRD and Raman results were subjected to peak separation to obtain the following relevant parameters:

[0081] XRD: After the 002 peak is separated, the aromaticity degree of the coal is obtained. The calculation formula is as follows:

[0082]

[0083]

[0084]

[0085] Where, is the distance between the monolayers of aromatic layers in the coke crystal structure; is the crystallite stacking height perpendicular to the aromatic lamellae; is the crystallite size parallel to the aromatic lamellae; and are the diffraction angles corresponding to the 002 peak and the 100 peak, respectively; and It corresponds to the half-height width of the 002 peak and the 100 peak; λ is the wavelength of the incident light, generally taken as λ = 0.15406nm; k 1 and k 2 is the form factor, generally taken k 1= 0.89, k 2= ​​1.84.

[0086] Utilizing the degree of aromatization To characterize the degree of graphitization, the integrated intensity (area) of the 002 peak and the γ peak obtained by XRD peak fitting can represent the number of aromatic carbon atoms (Car) and the number of aliphatic carbon atoms (Cal), respectively.

[0087]

[0088] Figure 6 The microstructure parameters of the modified coal obtained in Example 1 and Comparative Examples 1 to 3 are changed from Figure 6 It can be seen that deionized water coal washing has no effect on the microcrystalline structure of coal, while H2SO4 and flue gas coal washing have almost the same effect on the microcrystalline structure of coal. This is mainly because the acid formed after the flue gas dissolves in water also produces H ions, which has the same core nature as H2SO4. H ions will promote the breakage of branch chains or bridge chains in the coal structure, so it will promote the interlayer spacing of the microcrystalline structure ( Increase) and increase in stack height ( Increase), transforming the macromolecular structure into a small molecular weight structure ( Decreases), as the bridge chain and the side chain break, the remaining structures are stable, such as the benzene ring, so the degree of aromatization increases ( After coal washing with micro-nano bubbles, the generated free radicals, such as ·OH and ·O, have higher electronic energy than ·H and can destroy benzene rings or heterocyclic organic structures. This further increases the interlayer spacing and forms organic structures with smaller molecular weights. The internal organic links between different aromatic layers are also destroyed, resulting in a decrease in stacking height. The destruction of organic structures such as benzene rings significantly reduces the degree of aromatization in coal.

[0089] Raman: For the first order peak of Raman (800-2000cm -1 ) is processed into D1 peak, D2 peak, D3 peak, D4 peak and G peak, among which D1 peak is 1350 cm -1 The peak, usually called the defect band, corresponds to the graphite lattice vibration mode with A1g symmetry and is attributed to in-plane defects such as defects and heteroatoms; the D2 peak is at 1620 cm -1 The peak is always accompanied by the G1 peak, and its intensity decreases with the increase of carbon ordering degree; the D3 peak is usually between 1500 and 1550 cm -1 The D3 peak is likely related to the reaction site, thus affecting the reactivity of the coke. The D4 peak is at 1150 cm -1 The peak only appears in materials with a low degree of carbon ordering, such as bituminous coal and coal coke. The D4 peak may be attributed to the sp3-sp2 mixed site at the edge of the crystallite or the stretching vibration of C-C and C=C of polyenes, or it may be due to the reaction site. The G peak is 1580 cm -1 The peak corresponds to the E2g symmetric stretching vibration peak in the aromatic layer of graphite crystal. The characteristics of Raman spectrum have been shown to have a good correlation with the degree of ordering of carbon structure. Therefore, Raman spectrum can be used to analyze the effect of heat treatment on the evolution of coke structure. The following three band area ratios are mainly calculated: I D1 / I G ,I D3 / I G and I G / I ALL , where I D1 / I G is the relative content of unstable structure, I D3 / I G is the loudness content of the amorphous structure, I G / I ALL is the relative content of graphite structure.

[0090] like Figure 7 As shown, after deionized water washing coal, I D1 / I G , I D3 / I G and I G / I ALL Compared with the original coal, it is almost the same, indicating that deionized water washing does not change the structure and content of residual carbon, amorphous carbon and graphite carbon in coal, while H2SO4 and flue gas washing can change the structure and content of residual carbon, amorphous carbon and graphite carbon in coal. D1 / IG and I D3 / I G rapidly, I G / I ALL sharp rise, indicating that H+ions in the solution during H2SO4 and flue gas coal washing process will promote the elimination of disordered carbon and amorphous carbon, reduce the content of disordered carbon and amorphous carbon in coal, thereby increasing the relative content of graphite carbon, showing that the degree of graphitization is increased. After the coal is washed by the flue gas micro-nano bubble, I D1 / I G and I D3 / I G show an increasing trend, while I G / I ALL sharp decline, mainly because the high reaction activity of ·OH, ·O and other free radicals generated by the flue gas micro-nano bubble can destroy the graphite carbon structure (such as benzene ring or heterocyclic organic structure), and be converted into amorphous carbon and disordered carbon. The relative content of disordered carbon and amorphous carbon is more than that of H2SO4 and flue gas washing, which fully shows that the flue gas micro-nano bubble washing coal will promote the decomposition of graphite carbon structure, and reduce the degree of aromaticity of coal.

[0091] (3) Pore structure

[0092] The modified coal obtained in Example 1 and Comparative Examples 1-3 was analyzed by using an adsorption tester, the BET model was used to test the total specific surface area, and the BJH model was used to determine the pore size distribution of the coke.

[0093] Table 2 Pore structure parameters of modified coal in Example 1 and Comparative Examples 1-3

[0094]

[0095] Table 2 is the measured pore structure parameters of the modified coal. The deionized water washing has little effect on the specific surface area and pore volume of the coal. H2SO4 and flue gas coal washing will increase the micropore area, external surface area, total specific surface area and pore volume of the coal to some extent due to the breaking of ·H free radicals. After the coal is washed by the flue gas micro-nano bubble, the molecular weight of the coal is reduced due to the destructive effect of strong oxidizing free radicals such as ·OH and ·O, the degree of aromaticity is reduced, the internal pores of the coal are effectively opened, and a rich pore structure is formed, further improving the micropore area, external surface area, total specific surface area and pore volume of the coal.

[0096] (4) Surface chemical composition and element content

[0097] The modified coal obtained in Example 1 and Comparative Examples 1-3 was tested by XPS to obtain the surface chemical composition and element content of the modified coal. The S2p and N1s spectra of the XPS results were peak-separated, and the electron binding energies corresponding to different structures were as follows:

[0098] S2p:

[0099] Pyrite: Binding energy is between 158 and 159.6 eV.

[0100] Sulfide: Binding energy is between 161.2 and 163.6 eV.

[0101] Thiophene: The binding energy is between 164 and 164.4 eV.

[0102] Sulfoxide: The binding energy is between 165 and 166 eV.

[0103] Sulfone: The binding energy is between 167 and 168.3 eV.

[0104] Sulfate: Binding energy is between 168.4 and 175 eV.

[0105] N1s:

[0106] Pyridinic N (N-6): The binding energy is 398.7 eV ± 0.3 eV. This nitrogen atom is usually connected to a carbon atom and a hydrogen atom to form a five-membered ring structure.

[0107] Amino, imine, and amide nitrogen (NH): With a binding energy of 399.8 eV ± 0.2 eV, these nitrogen atoms can form bonds with hydrogen, carbon, and / or other elements.

[0108] Pyrrolic and pyridonic N (N-5): The binding energy is 400.3 eV ± 0.2 eV. These nitrogen atoms usually participate in the formation of five-membered or six-membered heterocyclic structures.

[0109] Quaternary Nitrogen (NQ): The binding energy is 401.4 eV ± 0.3 eV. This nitrogen atom acts as a substituent in the aromatic graphene structure and is connected to four carbon atoms.

[0110] Pyridine-N-oxide or Ammonia (NO): With a binding energy of 402.8 eV, this nitrogen atom can be part of a pyridine ring where the nitrogen atom is oxidized, or it can be the nitrogen in an ammonia molecule.

[0111] Adsorbed Nitrogen Oxides (N-OX): The binding energy is located at 405.0 eV ± 0.5 eV. These nitrogen atoms usually form bonds with oxygen atoms and may be connected to other elements such as carbon or hydrogen.

[0112] Figure 8 is the S / N form distribution characteristics of the modified coal obtained in Example 1, Comparative Examples 1-3, for S, from Figure 8 It can be seen that water washing does not change the distribution of S in coal, H2SO4 and flue gas washing coal can remove part of the pyrite, water-soluble sulfide and sulfate in coal and other inorganic sulfur, and does not destroy the structure of organic sulfur existing in the form of thiophene, sulfoxide and sulfone, and flue gas micro-nano bubble washing coal can promote the decomposition of part of the thiophene in coal and convert it into sulfoxide and sulfone, and also promote the decomposition of part of the sulfoxide and sulfone and convert it into sulfide and sulfate, ultimately reducing the content of organic sulfur in coal as a whole.

[0113] for N, from Figure 8 It can be seen that water washing does not change the distribution of N in coal, H2SO4 and flue gas washing coal can remove part of the decomposition of N-H (amino, imine, amide nitrogen), N-Q (quaternary ammonium nitrogen), N-O (oxidized pyridine nitrogen or ammonia nitrogen), N-OX (adsorbed nitrogen oxide) in coal, and does not destroy the structure of organic nitrogen existing in the form of pyridine nitrogen and pyrrole nitrogen, while flue gas micro-nano bubble washing coal can promote the decomposition of part of the pyridine nitrogen and pyrrole nitrogen in coal and convert it into N-H (amino, imine, amide nitrogen), N-Q (quaternary ammonium nitrogen), N-O (oxidized pyridine nitrogen or ammonia nitrogen), N-OX (adsorbed nitrogen oxide).

[0114] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A solid fuel comprehensive reforming device, characterized in that: The invention comprises a modification unit (1), wherein the modification unit (1) comprises at least one group of water washing components, each group of the water washing components comprises at least one water washing box (11), the water washing box (11) is used to hold the solid fuel to be modified, the water washing box (11) is provided with a water inlet (15), an air inlet (13), an air outlet (14) and a slurry outlet (16), the water inlet (15) is used to introduce a liquid solvent to form a mixed slurry; the air inlet (13) is used to introduce undesulfurized flue gas; the air outlet (14) is used to discharge the flue gas after the modification reaction; the slurry outlet (16) is used to discharge the modified mixed slurry, thereby achieving comprehensive modification of the solid fuel.

2. The solid fuel comprehensive reforming device according to claim 1, characterized in that: The air inlet (13) is provided with a micro-nano bubble generator (12) for passing the undesulfurized flue gas into the mixed slurry in the form of micro-nano bubbles.

3. The solid fuel comprehensive reforming device according to claim 1, characterized in that: The solid fuel comprehensive modification device further comprises a slurry conveying unit (2) and a slurry processing unit (3); the slurry conveying unit (2) is arranged between the modification unit (1) and the slurry processing unit (3) and is used to convey the modified mixed slurry into the slurry processing unit (3); the slurry processing unit (3) is used to perform solid-liquid separation and drying treatment on the modified mixed slurry to obtain modified solid fuel.

4. The solid fuel comprehensive reforming device according to claim 3, characterized in that: The slurry processing unit (3) comprises a solid-liquid separation component (31) and a drying component (32). One end of the solid-liquid separation component (31) is connected to the slurry conveying unit (2), and the other end thereof is connected to the drying component (32). The solid-liquid separation component (31) is used to separate the modified mixed slurry into solid and liquid, and to feed the separated solid matter into the drying component (32) for drying, thereby obtaining a modified solid fuel.

5. The solid fuel comprehensive reforming device according to claim 1, characterized in that: The groups of water washing components in the modification unit (1) are connected in parallel, and the water washing boxes (11) in the water washing components are connected in parallel.

6. The solid fuel comprehensive reforming device according to claim 1, characterized in that: The air inlet (13) is used to connect to the outlet of the dust collector (6) so as to allow the undesulfurized flue gas to enter the modification unit (1).

7. A power system comprising the solid fuel comprehensive reforming device according to any one of claims 1 to 6, characterized in that: The power system further comprises a boiler (4), a dust collector (6), a desulfurization tower (7) and a flue gas heat exchanger (8) connected in sequence along the flue gas flow direction; the air inlet (13) of the modification unit (1) is connected to the outlet of the dust collector (6) so as to feed the undesulfurized flue gas into the modification unit (1); the air outlet (14) of the modification unit (1) is respectively connected to the inlet of the desulfurization tower (7) and the inlet of the flue gas heat exchanger (8) so as to feed the flue gas after the modification reaction into the desulfurization tower (7) or the flue gas heat exchanger (8).

8. The power system according to claim 7, wherein: The outlet of the dust collector (6) is connected to the inlet of the desulfurization tower (7) and the air inlet (13) of the modification unit (1) respectively through a first control valve (71), so as to adjust the proportion of flue gas entering the modification unit (1) according to the working condition of the modification unit (1); the air outlet (14) of the modification unit (1) is connected to the inlet of the desulfurization tower (7) and the inlet of the flue gas heat exchanger (8) respectively through a second control valve (72), so as to control the flue gas after the modification reaction to enter the desulfurization tower (7) or the flue gas heat exchanger (8) according to the working condition of the modification unit (1).

9. The power system according to claim 8, wherein: The modification unit (1) further comprises a SO2 concentration detection component (17), which is arranged between the gas outlet (14) and the second control valve (72) to control the SO2 concentration in the flue gas after the modification reaction to enter the desulfurization tower (7) or the flue gas heat exchanger (8).

Images