Calcination process method of petroleum coke

Abstract

The invention discloses a calcining process method of petroleum coke, and relates to the technical field of carbon product preparation, and the calcining process method comprises the following steps: S1, crushing petroleum coke, adding red mud microspheres, mixing, ball-milling, drying, and sieving to obtain pretreated petroleum coke; s2, adding a porous cerium-doped nano iron oxide desulfurizer into the pretreated petroleum coke, and uniformly mixing to obtain a mixture to be calcined; s3, transferring the to-be-calcined mixture into a tubular furnace, heating in a nitrogen atmosphere, raising the temperature to 750-850 DEG C, and keeping the temperature for 1-2 hours to obtain desulfurized petroleum coke; naturally cooling, taking out, washing with a hydrochloric acid solution, washing with deionized water until the mixture is neutral, and carrying out suction filtration and drying; and S4, calcining the dried desulfurized petroleum coke at 900-1200 DEG C for 3-5 hours to obtain the calcined petroleum coke. According to the calcining process provided by the invention, the desulfurization rate of the petroleum coke can be effectively improved, and the calcined petroleum coke with low ash, low sulfur and high density is obtained.

Description

Technical Field

[0001] The present application relates to the field of carbon product preparation technology, and particularly to a calcination process method for petroleum coke. Background Art

[0002] Petroleum coke is an important industrial intermediate material, which is produced during the production of light oil by the delayed coking process. It can be used in industries such as metallurgy and chemical industry as raw materials for electrodes or the production of chemical products. When petroleum coke is used in the production of steelmaking graphite electrodes, aluminum smelting anodes, etc., it needs to go through a calcination process to meet the production requirements. The calcination process can remove volatile components, moisture and some sulfur components in petroleum coke, and improve density, strength, electrical conductivity and antioxidant properties.

[0003] During the calcination process, some impurities in petroleum coke are successively discharged due to heating. Adsorbed gases (O2, N2, CO2, CO, etc.) in petroleum coke are discharged at low temperatures; at around 450°C, monomer sulfur vaporizes and is discharged; when the temperature reaches above 1200°C, a part of organic sulfur is discharged, and the discharge of sulfur components causes a large amount of SO2 in the calcination flue gas. SO2 is one of the main air pollutants. The large-scale emission of SO2 will cause pollution such as acid rain and photochemical smog, which will endanger human health and damage the ecological balance. Therefore, flue gas with excessive SO2 must be desulfurized.

[0004] However, most effective desulfurization methods for petroleum coke in industry are based on high-temperature desulfurization conditions. First, the petroleum coke is heated to 600 - 1200°C, transferred to an electric furnace, and then the temperature is further raised to 1700 - 2300°C. After sulfur and other impurities are removed, the sulfur content of the obtained petroleum coke is <0.1%. However, desulfurization completely by increasing the temperature has low efficiency and high energy consumption, which is not conducive to large-scale desulfurization treatment. Summary of the Invention

[0005] In order to provide a calcination method for petroleum coke with high desulfurization efficiency and low energy consumption, the present application provides a calcination process method for petroleum coke.

[0006] A calcination process method for petroleum coke provided by the present application adopts the following technical solutions: A calcination process method for petroleum coke includes the following steps: S1. After crushing the petroleum coke, add red mud microspheres for mixed ball milling, dry and then screen to obtain pretreated petroleum coke; S2. Add a porous cerium-doped nano-iron oxide desulfurizer to the pretreated petroleum coke and mix evenly to obtain a mixture to be calcined; S3. Transfer the mixture to be calcined into a tubular furnace, heat it under a nitrogen atmosphere, and keep it at 750 - 850 °C for 1 - 2 h to obtain desulfurized petroleum coke; take it out after natural cooling, wash it with hydrochloric acid solution, and then wash it with deionized water until the mixture is neutral, then filter it by suction and dry it. S4. Calcinate the dried desulfurized petroleum coke at 900 - 1200 °C for 3 - 5 h to obtain calcined petroleum coke.

[0007] Preferably, the preparation method of the red mud microspheres comprises the following steps: Dry the red mud at 105 - 120 °C for 24 - 36 h, add plant fibers, mix evenly and then grind, dry, and pass through a 100 - 300 μm sieve to obtain red mud microspheres.

[0008] Preferably, the mass ratio of the red mud to the plant fibers is 1:0.002 - 0.006.

[0009] Preferably, the mass ratio of the petroleum coke to the red mud microspheres is 1:0.01 - 0.05.

[0010] Preferably, the porous cerium-doped nano-iron oxide desulfurizer is made from the following raw materials in parts by weight: 2 - 3 parts of cerium nitrate hexahydrate, 4 - 6 parts of iron nitrate hexahydrate, 200 - 400 parts of deionized water, 0.12 - 0.18 parts of plant fibers, and 3.5 - 7 parts of precipitant.

[0011] Preferably, the precipitant is ammonium carbonate.

[0012] Preferably, the plant fibers are one or more of loofah fiber, jute fiber, straw fiber, and bamboo fiber.

[0013] Preferably, the preparation method of the porous cerium-doped nano-iron oxide desulfurizer comprises the following steps: Pre-treat the plant fibers; Add cerium nitrate hexahydrate and iron nitrate hexahydrate to deionized water, stir evenly, add the pre-treated plant fibers, and disperse them evenly by ultrasonic waves; then add the precipitant under stirring conditions at 80 - 90 °C, continuously stir for 2 - 4 h, then cool to room temperature, filter, and wash several times, and then dry in an oven at 105 - 115 °C for 4 - 6 h, and then calcine at 450 - 550 °C for 3 - 4 h to obtain the porous cerium-doped nano-iron oxide desulfurizer.

[0014] Preferably, the method for pre-treating the plant fibers comprises the following steps: Dry the plant fibers and place them in a muffle furnace, pre-oxidize them at 200 - 300 °C for 2 - 3 h, cool to room temperature, immerse them in water, place them for 20 - 30 h, and then dry to obtain the pre-treated plant fibers.

[0015] Preferably, the mass ratio of the petroleum coke to the porous cerium-doped nano-iron oxide desulfurizer is 1:0.06-0.1.

[0016] In summary, the present application includes at least one of the following beneficial technical effects: 1. By adopting the above technical solution, the present application uses red mud microspheres and petroleum coke for compound ball milling treatment, which can fully expose sulfides. By adjusting the structure of petroleum coke, the internal graphite microcrystalline structure of petroleum coke is loosened, the contact area between sulfides and desulfurizer is increased, which helps the subsequent desulfurization treatment and enhances the desulfurization efficiency; the addition of red mud microspheres can also fill the gaps between petroleum coke particles, reduce the porosity, make the material more dense, improve the mechanical strength and thermal stability of the material, and the morphology of the composite material formed during the mixed ball milling process is more uniform; moreover, red mud also has a good removal effect on sulfur dioxide. The present application modifies red mud with plant fibers, which not only improves the mechanical strength and thermal stability of red mud, but also enhances the sulfur dioxide adsorption capacity of red mud; 2. The present application uses ammonium carbonate as a precipitating agent, and adopts the coprecipitation method to prepare cerium-doped iron oxide nano-adsorption desulfurizer with plant fibers as a carrier. By pre-oxidizing the plant fibers, the surface area and pore structure of the fibers can be increased, and further improve the desulfurization efficiency of the desulfurizer; 3. The petroleum coke calcination process provided by the present application produces calcined petroleum coke with a large density, good product stability, uniform quality, low ash and low sulfur, and has a wide range of applications. Detailed implementation mode

[0017] The following further elaborates the present application in conjunction with examples. Preparation example Preparation example 1 Preparation of red mud microspheres Preparation example 1.1

[0018] After drying 100 g of red mud at 105 °C for 36 h, 0.2 g of loofah fiber is added, mixed evenly and then ground. After drying, it is sieved through a 100 μm sieve to obtain red mud microspheres. Preparation example 1.2

[0019] After drying 100 g of red mud at 115 °C for 30 h, 0.4 g of loofah fiber is added, mixed evenly and then ground. After drying, it is sieved through a 200 μm sieve to obtain red mud microspheres. Preparation example 1.3

[0020] After drying 100 g of red mud at 120 °C for 24 h, 0.6 g of loofah fiber is added, mixed evenly and then ground. After drying, it is sieved through a 300 μm sieve to obtain red mud microspheres. Preparation example 1.4

[0021] The difference between Preparation Example 1.4 and Preparation Example 1.1 is that the plant fiber used in Preparation Example 1.4 is straw fiber. Preparation Example 1.5

[0022] The difference between Preparation Example 1.5 and Preparation Example 1.1 is that the plant fiber used in Preparation Example 1.5 is a composite of jute fiber and bamboo fiber with a mass ratio of 1:1. Preparation Example 2 Preparation of Porous Cerium-Doped Nano Iron Oxide Desulfurizer Preparation Example 2.1

[0023] S1. After drying 0.12 g of loofah fiber, place it in a muffle furnace and pre-oxidize it at 200 °C for 3 h. After cooling to room temperature, immerse it in water, leave it for 20 h, and then dry it to obtain the pretreated loofah fiber; S2. Add 2 g of cerium nitrate hexahydrate and 4 g of iron nitrate hexahydrate to 200 g of deionized water, stir evenly, add the pretreated loofah fiber, and ultrasonically disperse it evenly at 200 W for 1 h; then add 3.5 g of ammonium carbonate under stirring conditions at 80 °C and continuously stir for 2 h. Then cool to room temperature, filter, wash with deionized water 3 times, then dry in an oven at 105 °C for 6 h, and then calcine at 450 °C for 4 h to obtain the porous cerium-doped nano iron oxide desulfurizer. Preparation Example 2.2

[0024] S1. After drying 0.15 g of loofah fiber, place it in a muffle furnace and pre-oxidize it at 250 °C for 2.5 h. After cooling to room temperature, immerse it in water, leave it for 25 h, and then dry it to obtain the pretreated loofah fiber; S2. Add 2.5 g of cerium nitrate hexahydrate and 5 g of iron nitrate hexahydrate to 250 g of deionized water, stir evenly, add the pretreated loofah fiber, and ultrasonically disperse it evenly at 250 W for 1.5 h; then add 5.3 g of ammonium carbonate under stirring conditions at 85 °C and continuously stir for 3 h. Then cool to room temperature, filter, wash with deionized water 3 times, then dry in an oven at 110 °C for 5 h, and then calcine at 500 °C for 3.5 h to obtain the porous cerium-doped nano iron oxide desulfurizer. Preparation Example 2.3

[0025] S1. After drying 0.18 g of loofah fiber, place it in a muffle furnace and pre-oxidize it at 300 °C for 2 h. After cooling to room temperature, immerse it in water, leave it for 30 h, and then dry it to obtain the pretreated loofah fiber; S2. Add 3 g of cerium nitrate hexahydrate and 6 g of iron nitrate hexahydrate to 300 g of deionized water. After stirring evenly, add the pretreated loofah fiber, and ultrasonically disperse evenly for 2 h at 300 W. Subsequently, add 7 g of ammonium carbonate under stirring conditions at 90 °C, continuously stir for 4 h, then cool to room temperature and filter, wash with deionized water 3 times, then dry in an oven at 115 °C for 4 h, and then calcine at 550 °C for 3 h to obtain the porous cerium-doped nano iron oxide desulfurizer. Preparation Example 2.4

[0026] The difference between Preparation Example 2.4 and Preparation Example 2.1 is that the plant fiber used in Preparation Example 2.4 is straw fiber. Preparation Example 2.5

[0027] The difference between Preparation Example 2.5 and Preparation Example 2.1 is that the plant fiber used in Preparation Example 2.5 is a composite of jute fiber and bamboo fiber with a mass ratio of 1:1. Example Example 1

[0028] S1. After crushing 1000 g of petroleum coke, add 10 g of the red mud microspheres prepared in Preparation Example 1.1 for mixed ball milling. After drying, pass through a 200-micron sieve to obtain the pretreated petroleum coke. S2. Add 60 g of the porous cerium-doped nano iron oxide desulfurizer prepared in Preparation Example 2.1 to the pretreated petroleum coke, and mix evenly to obtain the mixture to be calcined. S3. Transfer the mixture to be calcined into a tubular furnace, heat it under a nitrogen atmosphere. After heating to 750 °C, hold for 2 h to obtain the desulfurized petroleum coke. Take it out after natural cooling, wash it with a 5% hydrochloric acid solution by mass, and then wash it with deionized water until the mixture is neutral, then filter by suction and dry. S4. After calcining the dried desulfurized petroleum coke at 900 °C for 5 h, the calcined petroleum coke is obtained. Example 2

[0029] S1. After crushing 1000 g of petroleum coke, add 10 g of the red mud microspheres prepared in Preparation Example 1.1 for mixed ball milling. After drying, pass through a 150-micron sieve to obtain the pretreated petroleum coke. S2. Add 60 g of the porous cerium-doped nano iron oxide desulfurizer prepared in Preparation Example 2.1 to the pretreated petroleum coke, and mix evenly to obtain the mixture to be calcined. S3. Transfer the mixture to be calcined into a tubular furnace, heat it under a nitrogen atmosphere. After heating to 800 °C, hold for 1.5 h to obtain the desulfurized petroleum coke. Take it out after natural cooling, wash it with a 5% hydrochloric acid solution by mass, and then wash it with deionized water until the mixture is neutral, then filter by suction and dry. S4. After calcining the dried desulfurized petroleum coke at 1100 °C for 4 h, calcined petroleum coke is obtained. Example 3

[0030] S1. After crushing 1000 g of petroleum coke, 10 g of red mud microspheres prepared in Preparation Example 1.1 are added for mixed ball milling. After drying, it is passed through a 100-micron sieve to obtain pretreated petroleum coke. S2. 60 g of porous cerium-doped nano-iron oxide desulfurizer prepared in Preparation Example 2.1 is added to the pretreated petroleum coke, and the mixture is evenly mixed to obtain a mixture to be calcined. S3. Transfer the mixture to be calcined into a tubular furnace and heat it under a nitrogen atmosphere. After heating to 850 °C, hold the temperature for 1 h to obtain desulfurized petroleum coke. After natural cooling, take it out, wash it with a 5% hydrochloric acid solution by mass, and then wash it with deionized water until the mixture is neutral, then filter by suction and dry. S4. After calcining the dried desulfurized petroleum coke at 1200 °C for 3 h, calcined petroleum coke is obtained. Example 4

[0031] The difference between Example 4 and Example 1 is that the red mud microspheres used in Example 4 are from Preparation Example 1.1, and the addition amount is 30 g. Example 5

[0032] The difference between Example 5 and Example 1 is that the red mud microspheres used in Example 5 are from Preparation Example 1.1, and the addition amount is 50 g. Example 6

[0033] The difference between Example 6 and Example 1 is that the red mud microspheres used in Example 6 are from Preparation Example 1.1, and the addition amount is 5 g. Example 7

[0034] The difference between Example 7 and Example 1 is that the red mud microspheres used in Example 7 are from Preparation Example 1.1, and the addition amount is 70 g. Example 8

[0035] The difference between Example 8 and Example 1 is that the red mud microspheres used in Example 8 are from Preparation Example 1.2, and the addition amount is 10 g. Example 9

[0036] The difference between Example 9 and Example 1 is that the red mud microspheres used in Example 9 are from Preparation Example 1.3, and the addition amount is 10 g. Example 10

[0037] The difference between Example 10 and Example 1 is that the red mud microspheres used in Example 10 are from Preparation Example 1.4, and the addition amount is 10 g. Example 11

[0038] The difference between Example 11 and Example 1 is that the red mud microspheres used in Example 11 are from Preparation Example 1.5, and the addition amount is 10 g. Example 12

[0039] The difference between Example 12 and Example 1 is that the porous cerium-doped nano-iron oxide desulfurizer used in Example 12 is from Preparation Example 2.1, and the addition amount is 80 g. Example 13

[0040] The difference between Example 13 and Example 1 is that the porous cerium-doped nano-iron oxide desulfurizer used in Example 13 is from Preparation Example 2.1, and the addition amount is 100 g. Example 14

[0041] The difference between Example 14 and Example 1 is that the porous cerium-doped nano-iron oxide desulfurizer used in Example 14 is from Preparation Example 2.1, and the addition amount is 40 g. Example 15

[0042] The difference between Example 15 and Example 1 is that the porous cerium-doped nano-iron oxide desulfurizer used in Example 15 is from Preparation Example 2.1, and the addition amount is 120 g. Example 16

[0043] The difference between Example 16 and Example 1 is that the red mud microspheres used in Example 16 are from Preparation Example 2.2, and the addition amount is 60 g. Example 17

[0044] The difference between Example 17 and Example 1 is that the red mud microspheres used in Example 17 are from Preparation Example 2.3, and the addition amount is 60 g. Example 18

[0045] The difference between Example 18 and Example 1 is that the red mud microspheres used in Example 18 are from Preparation Example 2.4, and the addition amount is 60 g. Example 19

[0046] The difference between Example 19 and Example 1 is that the red mud microspheres used in Example 19 are from Preparation Example 2.5, and the addition amount is 60 g. Comparative Example Comparative Example 1

[0047] The difference between Comparative Example 1 and Example 1 is that no red mud microspheres are added in Comparative Example 1. Comparative Example 2

[0048] The difference between Comparative Example 2 and Example 1 is that the porous cerium-doped nano-iron oxide desulfurizer was not added in Comparative Example 2. Comparative Example 3

[0049] The difference between Comparative Example 3 and Example 1 is that the desulfurizer used in Comparative Example 3 was 96% sodium hydroxide. Performance detection test

[0050] I. Using a microcomputer coulomb sulfur analyzer (CLS-3000) to measure the residual sulfur mass fraction of the calcined petroleum coke prepared in Examples 1-19 and Comparative Examples 1-3. The final desulfurization rate (%) of the petroleum coke was calculated according to the following formula, and the results are shown in Table 1; Desulfurization rate (%) = (w0 - w1) / w0 × 100% Where, w0 represents the sulfur mass fraction of the petroleum coke, %; w1 represents the residual sulfur mass fraction of the calcined petroleum coke, %.

[0051] II. Using GB / T 4511.1 "Determination Methods for True Relative Density, Apparent Relative Density and Porosity of Coke" to detect the true density (g / cm 3 ) of the calcined petroleum coke prepared in Examples 1-19 and Comparative Examples 1-3, and the results are shown in Table 1.

[0052] The specific detection results are as follows:

[0053] It can be seen from the detection results in Table 1 that a calcination process for petroleum coke provided by the present application can effectively improve the desulfurization rate of the calcined petroleum coke, and the density of the obtained calcined petroleum coke is relatively large and the quality is uniform.

[0054] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A calcination process method for petroleum coke, characterized in that: It includes the following steps: S1. After crushing petroleum coke, add red mud microspheres and carry out mixed ball milling. After drying, sieve to obtain pretreated petroleum coke. S2. Add porous cerium-doped nano-iron oxide desulfurizer to the pretreated petroleum coke and mix evenly to obtain a mixture to be calcined. S3. Transfer the mixture to be calcined into a tubular furnace and heat it under a nitrogen atmosphere. After heating to 750 - 850 °C, keep the temperature for 1 - 2 h to obtain desulfurized petroleum coke. Take it out after natural cooling, wash it with hydrochloric acid solution, and then wash it with deionized water until the mixture is neutral, then filter by suction and dry. S4. Calcine the dried desulfurized petroleum coke at 900 - 1200 °C for 3 - 5 h to obtain calcined petroleum coke.

2. The calcination process method of petroleum coke according to claim 1, characterized in that: The preparation method of the red mud microspheres includes the following steps: Dry red mud at 105 - 120 °C for 24 - 36 h, add plant fiber and mix evenly, then grind. After drying, sieve through a 100 - 300 μm sieve to obtain red mud microspheres.

3. The calcination process method of petroleum coke according to claim 2, characterized in that: The mass ratio of the red mud to the plant fiber is 1:0.002 - 0.

006.

4. A calcination process method for petroleum coke according to claim 1, characterized in that: The mass ratio of the petroleum coke to the red mud microspheres is 1:0.01 - 0.

05.

5. A calcination process method for petroleum coke according to claim 1, characterized in that: The porous cerium-doped nano-iron oxide desulfurizer is made from the following raw materials by weight: 2 - 3 parts of cerium nitrate hexahydrate, 4 - 6 parts of iron nitrate hexahydrate, 200 - 400 parts of deionized water, 0.12 - 0.18 parts of plant fiber, 3.5 - 7 parts of precipitant.

6. A calcination process method for petroleum coke according to claim 5, characterized in that: The precipitant is ammonium carbonate.

7. A calcination process method for petroleum coke according to claim 2 or 3 or 5, characterized in that: The plant fiber is one or a mixture of loofah fiber, jute fiber, straw fiber, and bamboo fiber.

8. A calcination process method for petroleum coke according to claim 5, characterized in that: The preparation method of the porous cerium-doped nano-iron oxide desulfurizer includes the following steps: Pretreat the plant fiber. Add cerium nitrate hexahydrate and iron nitrate hexahydrate to deionized water, stir evenly, then add the pretreated plant fiber and disperse it evenly by ultrasonic. Subsequently, add the precipitant under stirring conditions at 80 - 90 °C, continuously stir for 2 - 4 h, then cool to room temperature and filter, and wash several times. Then dry in an oven at 105 - 115 °C for 4 - 6 h, and then calcine at 450 - 550 °C for 3 - 4 h to obtain the porous cerium-doped nano-iron oxide desulfurizer.

9. A calcination process method for petroleum coke according to claim 8, characterized in that: The method for pretreating the plant fiber includes the following steps: Dry the plant fiber and place it in a muffle furnace, pre-oxidize it at 200 - 300 °C for 2 - 3 h. After cooling to room temperature, immerse it in water, leave it for 20 - 30 h, and then dry to obtain the pretreated plant fiber.

10. A calcination process method for petroleum coke according to claim 1, characterized in that: The mass ratio of the petroleum coke to the porous cerium-doped nano-iron oxide desulfurizer is 1:0.06 - 0.1.

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