Method and system for improving coal gasification performance by using calcium carbide furnace fly ash

Abstract

The invention discloses a method and a system for improving coal gasification performance by using calcium carbide furnace fly ash, and belongs to the technical field of coal gasification. The system comprises a first pickling tank, a second pickling tank, a drying tank, a mixing tank, a first fixed reaction bed and a second fixed reaction bed, HCl and HF solutions are firstly adopted for step-by-step ash removal, aluminosilicate in coal is accurately removed, active sites of alkaline earth metal (AAEM) are reserved, then calcium carbide furnace fly ash serves as a catalyst and is evenly dispersed with pulverized coal, the CO yield is increased, and the production cost is reduced. The coal gasification performance is effectively improved, and the utilization efficiency of coal resources is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal gasification, and in particular relates to a method and system for improving coal gasification performance by utilizing fly ash from a calcium carbide furnace. Background Art

[0002] Coal-to-calcium carbide is a traditional technology for converting coal into acetylene and other high-value-added energy products. Currently, alkali metals, alkaline earth metals, and transition metals have been proven to be effective catalysts in coal gasification. However, when the raw coal contains a high content of aluminosilicates, impurities cover the catalyst's active sites, accelerating sintering and deactivation, leading to a significant decrease in gasification efficiency over time. Furthermore, the preparation of composite catalysts is complex and relatively expensive.

[0003] Calcium carbide furnace fly ash, an inevitable solid byproduct of the calcium carbide production process, currently primarily disposes of it through high-temperature incineration, which poses secondary pollution risks and results in limited research on its resource utilization. Calcium carbide furnace fly ash contains significant amounts of alkali and alkaline earth metals, such as CaO, MgO, Na₂O, K₂O, and Fe₂O₃, totaling 92.28%. These alkali and alkaline earth metals act as catalysts in the coal gasification process, effectively reducing the degree of graphitization of coke and increasing gasification-active structures. While existing technologies have utilized modified fly ash (such as municipal solid waste incineration fly ash) for biomass gasification, these ash, primarily composed of sodium salts and aluminosilicates, have limited catalytic activity and require complex modification. Therefore, developing a process to enhance coal gasification performance is of great significance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for improving coal gasification performance by using fly ash from a calcium carbide furnace, so as to solve the technical problem of poor coal gasification performance.

[0005] To achieve the above object, the technical solution adopted by the present invention is: providing a system for improving coal gasification performance by using fly ash from a calcium carbide furnace, comprising a first pickling tank, a second pickling tank, a drying tank, a mixing tank, a first fixed reaction bed and a second fixed reaction bed; The first pickling tank is provided with a first liquid inlet on the top, and a first feed inlet and a first discharge port on the left and right sides respectively; the second pickling tank is provided with a second liquid inlet on the top, and a second feed inlet and a second discharge port on the left and right sides respectively; the drying tank is provided with a third feed inlet and a third discharge port on the left and right sides respectively; the mixing tank is provided with a fourth liquid inlet on the top, and a fourth feed inlet and a fourth discharge port on the left and right sides respectively; the first fixed reaction bed is provided with a first air inlet on the top, and a fifth feed inlet and a fifth discharge port on the left and right sides respectively; the second fixed reaction bed is provided with a second air inlet on the top, and a sixth feed inlet and a sixth discharge port on the left and right sides respectively; The second feed port and the first discharge port are connected through a first pipe, the third feed port and the second discharge port are connected through a second pipe, the fourth feed port and the third discharge port are connected through a third pipe, the fifth feed port and the fourth discharge port are connected through a fourth pipe, and the sixth feed port and the fifth discharge port are connected through a fifth pipe.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, a delivery pump is provided on the second pipeline, and a pressure pump is provided on the third pipeline.

[0007] Furthermore, the drying tank also includes a heating assembly; the heating assembly includes a heat pipe, which is arranged in a spiral ring on the circumference of the inner tank of the drying tank, and the inlet end and the outlet end respectively pass through the outer layer of the drying tank.

[0008] Furthermore, a stirring assembly is provided in the mixing tank, and the stirring assembly includes an ultrasonic stirring module; the ultrasonic stirring module is fixed on the upper surface of the mixing tank.

[0009] The system further includes an in-situ gas analyzer for monitoring the product CO yield. When the CO yield decreases, the CO2 flow rate is increased to improve the yield, thereby adjusting the gas flow rate in the second fixed reactor bed. One end of the in-situ gas analyzer is connected to the sixth discharge port, and the other end is connected to the second gas inlet.

[0010] The present invention also discloses a method for utilizing the above-mentioned system for improving coal gasification performance using calcium carbide furnace fly ash, comprising the following steps: S1, adding the raw coal to the first pickling tank, eluting with hydrochloric acid for 22-26 hours, then transporting the product to the second pickling tank through the first pipeline, eluting with hydrofluoric acid for 22-26 hours, and finally transporting it to the drying tank through the second pipeline for drying to obtain deashed coal; S2. Deashed coal is conveyed to a mixing tank via a third pipeline. 1-5 wt% of calcium carbide fly ash (CCFA) is added and uniformly mixed using a stirring assembly (ultrasonic mixing at a frequency of 30-50 kHz, a power of 250-350 W, and a time of 20-40 minutes). The mixture is then conveyed to a first fixed reaction bed via a fourth pipeline. Calcium carbide fly ash (CCFA) is rich in natural alkali metals and alkaline earth metals (CaO+MgO+KO+NaO>90%) and can be directly used as a high-efficiency catalyst. S3. N2 is introduced into the first fixed reaction bed, and the mixture is kept at 800-1000°C for 5-15 minutes. Then, the mixture is transported to the second fixed reaction bed through the fifth pipeline, and reacted at 800-1000°C for 20-40 minutes in a CO2 atmosphere to obtain coke and gasification products.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, the concentration of hydrochloric acid is 5-7 mol / L, and the mass fraction of hydrofluoric acid is 30-50%.

[0012] Furthermore, the drying temperature is 70-90° C., and the drying time is 10-14 hours.

[0013] Furthermore, the components of calcium carbide fly ash include: CaO 30-40wt%, MgO 10-20wt%, K2O 15-25wt%, Na2O 20-30wt%, Fe2O30.5-1.5wt% and impurities 5-10wt%.

[0014] Furthermore, the heating rate in S3 is 10-30°C / min.

[0015] Furthermore, the gas flow rate of CO2 is 400-500 mL / min.

[0016] The beneficial effects of the present invention are: 1. The present invention uses calcium carbide furnace fly ash as a catalyst, which increases the CO yield, effectively improves the coal gasification performance, and improves the utilization efficiency of coal resources.

[0017] 2. Add a stirring component and use ultrasonic assisted mixing to ensure uniform dispersion of CCFA and coal powder to avoid catalyst agglomeration.

[0018] 3. Set up an in-situ gas analyzer (such as online GC) to monitor the CO yield in real time and dynamically adjust the CO2 flow rate.

[0019] 4. Gradient acid washing pretreatment: Using HCl and HF solutions for step-by-step deashing can accurately remove aluminosilicates in coal, avoid their poisoning effect on the catalyst, and ensure the long-term utilization of AAEM active sites in calcium carbide fly ash. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a process flow chart of the present invention; Figure 2 SEM images of samples ZDC char, ZDC-FA char, D-ZDC char and D-ZDC-FA char; Figure (a) is the SEM image of ZDC char, Figure (b) is the SEM image of ZDC-FA char, Figure (c) is the SEM image of D-ZDC char, and Figure (d) is the SEM image of D-ZDC-FA char; Figure 3 is the EDS diagram of D-ZDC-FAchar; Figure 4XRD patterns of samples ZDC char, ZDC-FA char, D-ZDC char and D-ZDC-FA char; Figure 5 is the XRD spectrum fitting curve of ZDC char; Figure 6 is the XRD spectrum fitting curve of ZDC-FA char; Figure 7 is the XRD spectrum fitting curve of D-ZDC char; Figure 8 is the XRD spectrum fitting curve of D-ZDC-FA char; The symbols of each component are as follows: 1. First pickling tank; 2. Second pickling tank; 3. Drying tank; 4. Mixing tank; 5. Stirring assembly; 6. First fixed reaction bed; 7. Second fixed reaction bed; 8. In-situ gas analyzer. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. In the examples, where specific conditions are not specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. It is obvious to those skilled in the art that various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, and all inventions and creations utilizing the present invention are protected.

[0022] The calcium carbide fly ash (CCFA) used in the following embodiments comprises 32.91 wt% CaO, 12.96 wt% MgO, 19.77 wt% K₂O, 25.38 wt% Na₂O, 31.26 wt% Fe₂O, and 7.72 wt% impurities. It is rich in alkali metals and alkaline earth metals (AAEM). The raw coal used is Zhundong coal (ZDC), purchased from Xinjiang Yihua Mining Co., Ltd.

[0023] Example 1 A system for improving coal gasification performance using fly ash from a calcium carbide furnace comprises a first pickling tank 1, a second pickling tank 2, a drying tank 3, a mixing tank 4, a first fixed reaction bed 6, and a second fixed reaction bed 7; The first pickling tank 1 is provided with a first liquid inlet on the top, and a first feed inlet and a first discharge port on the left and right sides respectively; the second pickling tank 2 is provided with a second liquid inlet on the top, and a second feed inlet and a second discharge port on the left and right sides respectively; the drying tank 3 is provided with a third feed inlet and a third discharge port on the left and right sides respectively; the mixing tank 4 is provided with a fourth liquid inlet on the top, and a fourth feed inlet and a fourth discharge port on the left and right sides respectively; the first fixed reaction bed 6 is provided with a first air inlet on the top, and a fifth feed inlet and a fifth discharge port on the left and right sides respectively; the second fixed reaction bed 7 is provided with a second air inlet on the top, and a sixth feed inlet and a sixth discharge port on the left and right sides respectively.

[0024] The second feed port and the first discharge port are connected via a first pipe, the third feed port and the second discharge port are connected via a second pipe, the fourth feed port and the third discharge port are connected via a third pipe, the fifth feed port and the fourth discharge port are connected via a fourth pipe, and the sixth feed port and the fifth discharge port are connected via a fifth pipe. A delivery pump is provided on the second pipe, and a pressure pump is provided on the third pipe.

[0025] A method for utilizing the above-mentioned system for improving coal gasification performance using calcium carbide furnace fly ash comprises the following steps: S1. Zhundong coal (ZDC) is added to the first pickling tank 1 and eluted with 5 mol / L hydrochloric acid for 26 hours. The product is then transported to the second pickling tank 2 through a first pipeline and eluted with 50% hydrofluoric acid for 22 hours. Finally, the product is transported to the drying tank 3 through a second pipeline and dried at 90°C for 10 hours to obtain deashed coal. S2, the deashed coal is transported to the mixing tank 4 through the third pipeline, 5wt% of calcium carbide fly ash is added and mixed evenly, and then the mixture is transported to the first fixed reaction bed 6 through the fourth pipeline; S3. N2 is introduced into the first fixed reaction bed 6, and the temperature is increased from room temperature to 800°C at a heating rate of 10°C / min. The mixture is then placed in the reaction system and kept warm for 15 minutes. The mixture is then transported to the second fixed reaction bed 7 through the fifth pipeline, and the temperature is increased from room temperature to 800°C at a heating rate of 10°C / min. The mixture is placed in a CO2 atmosphere (gas flow rate of 400 mL / min) and reacted for 40 minutes to obtain coke and gasification products.

[0026] Example 2 A system for improving coal gasification performance using fly ash from a calcium carbide furnace comprises a first pickling tank 1, a second pickling tank 2, a drying tank 3, a mixing tank 4, a first fixed reaction bed 6, and a second fixed reaction bed 7; The first pickling tank 1 is provided with a first liquid inlet on the top, and a first feed inlet and a first discharge port on the left and right sides respectively; the second pickling tank 2 is provided with a second liquid inlet on the top, and a second feed inlet and a second discharge port on the left and right sides respectively; the drying tank 3 is provided with a third feed inlet and a third discharge port on the left and right sides respectively; the mixing tank 4 is provided with a fourth liquid inlet on the top, and a fourth feed inlet and a fourth discharge port on the left and right sides respectively; the first fixed reaction bed 6 is provided with a first air inlet on the top, and a fifth feed inlet and a fifth discharge port on the left and right sides respectively; the second fixed reaction bed 7 is provided with a second air inlet on the top, and a sixth feed inlet and a sixth discharge port on the left and right sides respectively.

[0027] The second feed port and the first discharge port are connected through a first pipe, the third feed port and the second discharge port are connected through a second pipe, the fourth feed port and the third discharge port are connected through a third pipe, the fifth feed port and the fourth discharge port are connected through a fourth pipe, and the sixth feed port and the fifth discharge port are connected through a fifth pipe.

[0028] A delivery pump is provided on the second pipeline, and a pressure pump is provided on the third pipeline; the drying tank 3 also includes a heating assembly; the heating assembly includes a heat pipe, which is arranged in a spiral ring on the circumference of the inner tank of the drying tank 3, and the inlet end and the outlet end respectively pass through the outer layer of the drying tank 3; the mixing tank 4 is also provided with a stirring assembly 5, and the stirring assembly 5 includes an ultrasonic stirring module; the ultrasonic stirring module is fixed on the upper surface of the mixing tank 4.

[0029] A method for utilizing the above-mentioned system for improving coal gasification performance using calcium carbide furnace fly ash comprises the following steps: S1. Zhundong coal (ZDC) was added to the first pickling tank 1 and eluted with 7 mol / L hydrochloric acid for 22 hours. The product was then transported to the second pickling tank 2 through a first pipeline and eluted with 30% hydrofluoric acid for 26 hours. Finally, the product was transported to the drying tank 3 through a second pipeline and dried at 70°C for 14 hours to obtain deashed coal. S2, the deashed coal is transported to the mixing tank 4 through the third pipeline, 1 wt% of calcium carbide fly ash is added, and the raw materials are uniformly mixed by the stirring assembly 5 (ultrasonic mixing, frequency of 30 kHz, power of 350 W, time for 40 minutes), and then the mixture is transported to the first fixed reactor 6 through the fourth pipeline; S3. N2 is introduced into the first fixed reaction bed 6, and the temperature is increased from room temperature to 1000°C at a heating rate of 30°C / min. The mixture is then placed in the reaction system and kept warm for 5 minutes. The mixture is then transported to the second fixed reaction bed 7 through the fifth pipeline, and the temperature is increased from room temperature to 1000°C at a heating rate of 30°C / min. The mixture is placed in a CO2 atmosphere (gas flow rate of 500 mL / min) and reacted for 20 minutes to obtain coke and gasification products.

[0030] Example 3 A system that uses calcium carbide furnace fly ash to improve coal gasification performance, such as Figure 1 As shown, it includes a first pickling tank 1, a second pickling tank 2, a drying tank 3, a mixing tank 4, a first fixed reaction bed 6 and a second fixed reaction bed 7; The first pickling tank 1 is provided with a first liquid inlet on the top, and a first feed inlet and a first discharge port on the left and right sides respectively; the second pickling tank 2 is provided with a second liquid inlet on the top, and a second feed inlet and a second discharge port on the left and right sides respectively; the drying tank 3 is provided with a third feed inlet and a third discharge port on the left and right sides respectively; the mixing tank 4 is provided with a fourth liquid inlet on the top, and a fourth feed inlet and a fourth discharge port on the left and right sides respectively; the first fixed reaction bed 6 is provided with a first air inlet on the top, and a fifth feed inlet and a fifth discharge port on the left and right sides respectively; the second fixed reaction bed 7 is provided with a second air inlet on the top, and a sixth feed inlet and a sixth discharge port on the left and right sides respectively.

[0031] The second feed port and the first discharge port are connected through a first pipe, the third feed port and the second discharge port are connected through a second pipe, the fourth feed port and the third discharge port are connected through a third pipe, the fifth feed port and the fourth discharge port are connected through a fourth pipe, and the sixth feed port and the fifth discharge port are connected through a fifth pipe.

[0032] A delivery pump is provided on the second pipeline, and a pressure pump is provided on the third pipeline; the drying tank 3 also includes a heating assembly; the heating assembly includes a heat pipe, which is arranged in a spiral ring on the circumference of the inner tank of the drying tank 3, and the inlet end and the outlet end respectively pass through the outer layer of the drying tank 3; the mixing tank 4 is also provided with a stirring assembly 5, and the stirring assembly 5 includes an ultrasonic stirring module; the ultrasonic stirring module is fixed on the upper surface of the mixing tank 4; the system also includes an in-situ gas analyzer 8, one end of the in-situ gas analyzer 8 is connected to the sixth discharge port, and the other end is connected to the second air inlet.

[0033] A method for utilizing the above-mentioned system for improving coal gasification performance using calcium carbide furnace fly ash comprises the following steps: S1. Add Zhundong coal (ZDC) to the first pickling tank 1, elute with 6 mol / L hydrochloric acid for 24 hours, repeatedly wash the solid with deionized water until the filtrate is neutral, then transport the product (ZDC-HCl) to the second pickling tank 2 through the first pipeline, elute with 40% hydrofluoric acid for 24 hours, repeatedly wash the solid with deionized water until the filtrate is neutral, and finally transport it to the drying tank 3 through the second pipeline and dry it at 80°C for 12 hours to obtain deashed coal (D-ZDC); S2. Deashed coal (D-ZDC) is transported to a mixing tank 4 via a third pipeline. 3 wt% calcium carbide fly ash (CCFA) is added and then uniformly mixed using a stirring assembly 5 (ultrasonic mixing at a frequency of 40 kHz, a power of 300 W, and a time of 30 minutes). The mixture (D-ZDC-FA) is then transported to a first fixed reactor 6 via a fourth pipeline. S3. N2 is introduced into the first fixed reaction bed 6, and the temperature is increased from room temperature to 900°C at a heating rate of 20°C / min. The mixture is then placed in the reaction system and kept warm for 10 minutes. The mixture is then transported to the second fixed reaction bed 7 through the fifth pipeline, and the temperature is increased from room temperature to 900°C at a heating rate of 20°C / min. The mixture is placed in a CO2 atmosphere (gas flow rate of 450 mL / min) and reacted for 30 minutes to obtain coke and gasification products.

[0034] Comparative Example 1 The difference between this comparative example and Example 3 is that steps S1 and S2 are omitted, and Zhundong coal (ZDC) is directly placed in the first fixed reaction bed for reaction. The remaining implementation conditions are the same as those in Example 3, and coke and gasification products are obtained.

[0035] Comparative Example 2 The difference between this comparative example and Example 3 is that step S1 is omitted, Zhundong coal (ZDC) is mixed with calcium carbide fly ash (CCFA), and the remaining implementation conditions are the same as those in Example 3 to obtain coke and gasification products.

[0036] Comparative Example 3 The difference between this comparative example and Example 3 is that step S2 is omitted, and the deashed coal (D-ZDC) is directly placed in the first fixed reaction bed for reaction. The other implementation conditions are the same as those in Example 3, and coke and gasification products are obtained.

[0037] Comparative Example 4 The difference between this comparative example and Example 3 is that the CO2 gasification treatment in steps S1, S2 and S3 is omitted, and the Zhundong coal (ZDC) is directly placed in the first fixed reaction bed for reaction. The other implementation conditions are the same as those in Example 3, and Zhundong coal coke (ZDC char) and gasification products are obtained.

[0038] Comparative Example 5 The difference between this comparative example and Example 3 is that the CO2 gasification treatment in step S1 and step S3 is omitted, Zhundong coal (ZDC) is mixed with calcium carbide fly ash (CCFA), and the remaining implementation conditions are the same as those in Example 3 to obtain Zhundong coal-calcium carbide fly ash coke (ZDC-FA char) and gasification products.

[0039] Comparative Example 6 The difference between this comparative example and Example 3 is that the CO2 gasification treatment in step S2 and step S3 is omitted, and the deashed coal (D-ZDC) is directly placed in the first fixed reaction bed for reaction. The other implementation conditions are the same as those in Example 3, and deashed Zhundong coal coke (D-ZDC char) and gasification products are obtained.

[0040] Comparative Example 7 The difference between this comparative example and Example 3 is that the CO2 gasification treatment in step S3 is omitted, and the other implementation conditions are the same as those in Example 3, thereby obtaining deashed-Zhundong coal-calcium carbide fly ash coke (D-ZDC-FA char).

[0041] The performance of the coke and gasification products obtained in Example 3 and Comparative Examples 1-3 was tested, and the results are shown in Table 1.

[0042] Table 1 Comparison of reaction performance under different implementation conditions

[0043] As shown in Table 1, the addition of calcium carbide fly ash (CCFA) significantly increases the CO yield in Comparative Example 2 compared to Comparative Example 1 (Example 3 and Comparative Example 3). Compared to Comparative Example 3, the carbon conversion time in Example 3 was shortened from 54 minutes to 28 minutes. The gasification reactivity index in Comparative Example 2 increased by 1.8 times compared to Comparative Example 1, and by 1.4 times compared to Comparative Example 3. These results demonstrate that using calcium carbide fly ash as a coal gasification catalyst can effectively improve coal gasification performance.

[0044] The samples obtained in Comparative Examples 4-7 were analyzed by SEM, XRD and other characterization methods. Figure 2-Figure 8 As shown, by comparing the coke samples with and without carbide fly ash added ( Figure 2 The surface of the sample with added calcium carbide fly ash is rougher, which is more conducive to the contact between coke and gasification agent (CO2). Figure 3-Figure 8 ) found that calcium carbide fly ash not only causes defects in the lattice structure of coke edges, but also causes defects within the crystals. This shows that its catalytic effect not only increases the reaction rate but also changes the physical and chemical properties of coke.

[0045] Figure 3This is the elemental distribution diagram of Na, Mg, K, and Ca in D-ZDC-FA char. No alkali metal and alkaline earth metal element aggregation is found on the coke surface. This is because alkali metals and alkaline earth metals have good dispersibility and mobility. During the pyrolysis process, Na, Mg, K, and Ca in calcium carbide fly ash are evenly distributed on the coke surface. The sites corroded by alkali metals and alkaline earth metals are generally considered to be the active sites of gasification reactions. The alkali metals and alkaline earth metals on the coke surface have catalytic properties and exist mainly in the form of COM, which adsorbs CO2. AAEM, as active centers, are evenly dispersed on the carbon matrix, increasing the active surface ratio, promoting the decomposition of fatty side chains and aromatic compounds during the gasification process, and accelerating the gasification reaction.

[0046] Although the data such as the short-term CO yield of the sample after pickling in Table 1 are slightly lower than those in Comparative Example 2, Figure 2 It can be seen that after pickling treatment, the pores on the coke surface are more developed (D-ZDC char and D-ZDC-FA char), which is conducive to the diffusion of gasifying agent (CO2). Figure 3-Figure 8 The acid-washed sample exhibits increased crystal defects, demonstrating more fully exposed AAEM active sites. Therefore, the step-by-step acid washing removes aluminosilicate impurities, reducing their toxic effects on the catalyst, an effect that positively impacts the long-term stability of the catalyst.

[0047] The above results show that CCFA can effectively improve the performance of coal gasification reaction.

Claims

1. A system for improving coal gasification performance using fly ash from calcium carbide furnaces, characterized in that: It comprises a first pickling tank (1), a second pickling tank (2), a drying tank (3), a mixing tank (4), a first fixed reaction bed (6) and a second fixed reaction bed (7); The first pickling tank (1) is provided with a first liquid inlet on the top, and a first feed inlet and a first discharge port on the left and right sides respectively; the second pickling tank (2) is provided with a second liquid inlet on the top, and a second feed inlet and a second discharge port on the left and right sides respectively; the drying tank (3) is provided with a third feed inlet and a third discharge port on the left and right sides respectively; the mixing tank (4) is provided with a fourth liquid inlet on the top, and a fourth feed inlet and a fourth discharge port on the left and right sides respectively; the first fixed reaction bed (6) is provided with a first air inlet on the top, and a fifth feed inlet and a fifth discharge port on the left and right sides respectively; the second fixed reaction bed (7) is provided with a second air inlet on the top, and a sixth feed inlet and a sixth discharge port on the left and right sides respectively; The second feed port and the first discharge port are connected through a first pipe, the third feed port and the second discharge port are connected through a second pipe, the fourth feed port and the third discharge port are connected through a third pipe, the fifth feed port and the fourth discharge port are connected through a fourth pipe, and the sixth feed port and the fifth discharge port are connected through a fifth pipe.

2. The system for improving coal gasification performance by using calcium carbide furnace fly ash according to claim 1, characterized in that: The second pipeline is provided with a delivery pump, and the third pipeline is provided with a pressure pump.

3. The system for improving coal gasification performance using calcium carbide furnace fly ash according to claim 1, characterized in that: The drying tank (3) further comprises a heating assembly; the heating assembly comprises a heat pipe, the heat pipe being arranged in a spiral ring on the circumference of the inner shell of the drying tank (3), and the inlet end and the outlet end respectively passing through the outer layer of the drying tank (3).

4. The system for improving coal gasification performance using calcium carbide furnace fly ash according to claim 1, characterized in that: The mixing tank (4) is further provided with a stirring assembly (5), and the stirring assembly (5) comprises an ultrasonic stirring module; the ultrasonic stirring module is fixed on the upper surface of the mixing tank (4).

5. The system for improving coal gasification performance by using calcium carbide furnace fly ash according to claim 1, characterized in that: It also includes an in-situ gas analyzer (8), one end of the in-situ gas analyzer (8) is connected to the sixth discharge port, and the other end is connected to the second gas inlet.

6. A method for improving coal gasification performance by using the system for improving coal gasification performance by using calcium carbide furnace fly ash according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, adding raw coal to the first pickling tank (1), eluting with hydrochloric acid for 22-26 hours, then transporting the product to the second pickling tank (2) through the first pipeline, eluting with hydrofluoric acid for 22-26 hours, and finally transporting it to the drying tank (3) through the second pipeline for drying to obtain deashed coal; S2, transporting the deashed coal to a mixing tank (4) through a third pipeline, adding 1-5 wt% of calcium carbide fly ash, and then uniformly mixing the raw materials through a stirring assembly (5), and then transporting the mixture to a first fixed reaction bed (6) through a fourth pipeline; S3. N2 is introduced into the first fixed reaction bed (6), and the mixture is kept at 800-1000°C for 5-15 minutes. The mixture is then transported to the second fixed reaction bed (7) through the fifth pipeline, and reacted in a CO2 atmosphere at 800-1000°C for 20-40 minutes to obtain coke and gasification products.

7. The method of improving coal gasification performance by using calcium carbide furnace fly ash according to claim 6, characterized in that: The concentration of hydrochloric acid is 5-7 mol / L, and the mass fraction of hydrofluoric acid is 30-50%.

8. The method of improving coal gasification performance by using calcium carbide furnace fly ash according to claim 6, characterized in that: The drying temperature is 70-90° C., and the drying time is 10-14 hours.

9. The method of improving coal gasification performance by using calcium carbide furnace fly ash according to claim 6, characterized in that: The heating rate in S3 is 10-30°C / min.

10. The method of improving coal gasification performance by using calcium carbide furnace fly ash according to claim 6, characterized in that: The gas flow rate of the CO2 is 400-500 mL / min.

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