A treatment process for reducing sulfur content in calcined petroleum coke

Abstract

The present invention relates to a treatment process for reducing the sulfur content of calcined petroleum coke, and belongs to the technical field of petroleum coke desulfurization process. The treatment process comprises grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then performing a high-temperature calcination treatment, which is completed after cooling; the preparation of the composite catalyst comprises: grinding and mixing rectorite, light calcium carbonate and anhydrous ethanol, adding mercaptosuccinic acid and stirring and mixing, adding a coupling agent and mixing it, and then heating it, filtering out the solid matter, vacuum drying and calcining it, adding ethylene glycol and deionized water and mixing it, adding nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, adding ammonia water and heating and stirring it, cooling it to room temperature and then centrifuging it, washing it three times with an ethanol solution, vacuum drying it and then calcining it. The treatment process of the composite catalyst prepared by the present invention for catalyzing the desulfurization of petroleum coke has excellent desulfurization effect and can effectively reduce the sulfur content of calcined petroleum coke.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum coke desulfurization technology and relates to a treatment process for reducing the sulfur content of calcined petroleum coke. Background Art

[0002] Petroleum coke is primarily made from vacuum residue. It is primarily produced by blending petroleum-derived raw materials such as catalytic cracking oil slurry, ethylene tar, refinery waste oil, and scum, all within the refinery's overall material balance. The mixture is then cracked and carbonized in processes such as delayed coking or fluidized coking. Petroleum coke has a dense intrinsic structure, primarily composed of carbon, but also contains other heteroatoms such as nitrogen, sulfur, iron, zinc, and cadmium. Based on its appearance and properties, petroleum coke can be divided into sponge coke (commonly used as fuel, reducing agent, anode material, and prebaked anodes), shot coke (used for fuel), and needle coke (used in the production of graphite electrodes and lithium battery anode raw materials). High-sulfur petroleum coke is typically used as fuel and in the preparation of low-value-added products such as reducing agents, while low-sulfur petroleum coke is primarily used in lithium battery anode materials and prebaked anodes, offering a relatively higher value-added product. To improve its utilization efficiency, petroleum coke requires desulfurization.

[0003] During the calcination process, sulfides are removed from petroleum coke, and the calcined petroleum coke is called "cooked coke." Industrially, petroleum coke calcination temperatures typically range from 1100 to 1400 degrees Celsius, achieving a desulfurization rate of approximately 50%. Within this temperature range, the carbonaceous structure begins to rearrange, and as this rearrangement occurs, the sulfides in the petroleum coke begin to be released. However, calcination temperatures are too high, often requiring the use of catalysts to improve desulfurization efficiency. Catalysts can lower the decomposition temperature of sulfides, thereby achieving higher desulfurization rates at lower temperatures. Furthermore, catalysts promote sulfide conversion, reduce corrosion on calcination equipment, and extend its service life. When selecting a catalyst, it is important to consider its activity, selectivity, and stability during the calcination process. By optimizing the type and dosage of catalyst, the desulfurization efficiency of petroleum coke can be further enhanced while reducing production costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a treatment process for reducing the sulfur content of calcined petroleum coke. The composite catalyst prepared by the present invention is used for catalytic desulfurization of petroleum coke and has excellent desulfurization effect.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, calcining it, and cooling it to complete the treatment.

[0007] As a preferred technical solution of the present invention, in the treatment process, the screening is through a 50-100 mesh sieve; the mixing time is 30-40 minutes; and the calcination treatment is calcination at 620-690° C. for 70-90 minutes.

[0008] The present invention discloses a method for preparing the composite catalyst, comprising the following steps:

[0009] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0010] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash with ethanol solution several times, vacuum dry and then calcine to obtain a composite catalyst.

[0011] As a preferred technical solution of the present invention, in step 1), the grinding and mixing is performed at a rotation speed of 400-500 r / min for 40-60 min; and the stirring and mixing time is 40-50 min.

[0012] As a preferred technical solution of the present invention, in step 1), the vacuum drying is drying at 80°C to constant weight; the heating treatment is stirring at 50-60°C and 500-700 r / min for 4-5 hours.

[0013] As a preferred technical solution of the present invention, in step 1), the mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is (8-9): (0.06-0.08): (0.2-0.4): (30-35): (3.2-3.4).

[0014] As a preferred technical solution of the present invention, in step 1), the coupling agent is a zirconium-aluminum coupling agent; and the calcination is performed at a temperature of 500° C. for 3-4 hours.

[0015] As a preferred technical solution of the present invention, in step 2), the heating and stirring is heating at a temperature of 200° C. for 2.0-2.5 hours; and the concentration of the ethanol solution is 70 wt %.

[0016] As a preferred technical solution of the present invention, in step 2), the calcination is carried out at a temperature of 400-420° C. for 1.0-1.2 h.

[0017] As a preferred technical solution of the present invention, in step 2), the mass ratio of the composite carrier, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate and ammonia water is 20-24:70-80:20-22:0.6-0.8:2.4-2.8:10-12; the concentration of the ammonia water is 24%.

[0018] Beneficial effects of the present invention:

[0019] The present invention forms a composite by rectorite and calcium carbonate, then attaches mercaptosuccinic acid to the composite, modifies it by grafting a zirconium-aluminum coupling agent, and then performs calcination activation, thereby significantly improving the pore structure and specific surface area of ​​the composite carrier and the adsorption capacity for active metal nickel / molybdenum. At the same time, the alumina / zirconium oxide layer can effectively increase the thermal stability of the rectorite and reduce the collapse phenomenon caused by excessive calcination activation or calcination desulfurization. DETAILED DESCRIPTION

[0020] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0021] Example 1

[0022] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then calcining it, and cooling it to room temperature;

[0023] In the treatment process, the screening is through a 60-mesh sieve; the mixing time is 30 minutes; and the calcination treatment is calcination at 620° C. for 70 minutes.

[0024] The preparation method of the composite catalyst comprises the following steps:

[0025] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0026] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash three times with ethanol solution, vacuum dry and calcine to obtain a composite catalyst.

[0027] In step 1), the grinding and mixing is performed at a speed of 400 r / min for 40 minutes; the stirring and mixing time is 40 minutes; the heat treatment is performed at a temperature of 50°C and a speed of 500 r / min for 4 hours; the vacuum drying is performed at a temperature of 80°C to constant weight; the calcination is performed at a temperature of 500°C for 3 hours; the mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is 8:0.06:0.2:30:3.2; and the coupling agent is a zirconium-aluminum coupling agent.

[0028] In step 2), the heating and stirring is performed at 200° C. for 2.0 h; the concentration of the ethanol solution is 70 wt %; the calcination is performed at 400° C. for 1.0 h; the mass ratio of the composite support, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate, and ammonia water is 20:70:20:0.6:2.4:10; and the concentration of the ammonia water is 24%.

[0029] Example 2

[0030] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then calcining it at high temperature, and cooling it to room temperature;

[0031] In the treatment process, the screening is through a 60-mesh sieve; the mixing time is 32 minutes; and the high-temperature calcination treatment is calcination at 630° C. for 75 minutes.

[0032] The preparation method of the composite catalyst comprises the following steps:

[0033] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0034] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash three times with ethanol solution, vacuum dry and calcine to obtain a composite catalyst.

[0035] In step 1), the grinding and mixing is performed at a speed of 420 r / min for 45 minutes; the stirring and mixing time is 42 minutes; the heat treatment is performed at a temperature of 52° C. and a speed of 550 r / min for 4.2 hours; the vacuum drying is performed at a temperature of 80° C. to constant weight; and the calcination is performed at a temperature of 500° C. for 3.2 hours. The mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol, and coupling agent is 8.2:0.07:0.25:31:3.3; and the coupling agent is a zirconium-aluminum coupling agent.

[0036] In step 2), the heating and stirring is performed at 200° C. for 2.1 hours; the concentration of the ethanol solution is 70 wt %; the calcination is performed at 410° C. for 1.1 hours; the mass ratio of the composite support, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate, and ammonia water is 21:72:20.5:0.65:2.5:10.5; and the concentration of the ammonia water is 24%.

[0037] Example 3

[0038] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then calcining it at high temperature, and cooling it to room temperature;

[0039] In the treatment process, the screening is through a 60-mesh sieve; the mixing time is 35 minutes; and the high-temperature calcination treatment is calcination at 650° C. for 80 minutes.

[0040] The preparation method of the composite catalyst comprises the following steps:

[0041] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0042] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash three times with ethanol solution, vacuum dry and calcine to obtain a composite catalyst.

[0043] In step 1), the grinding and mixing is performed at a speed of 450 r / min for 50 minutes; the stirring and mixing time is 45 minutes; the heat treatment is performed at a temperature of 55°C and a speed of 600 r / min for 4.5 hours; the vacuum drying is performed at a temperature of 80°C to constant weight; and the calcination is performed at a temperature of 500°C for 3.5 hours. The mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is 8.5:0.07:0.3:32:3.3; and the coupling agent is a zirconium-aluminum coupling agent.

[0044] In step 2), the heating and stirring is performed at 200° C. for 2.2 hours; the concentration of the ethanol solution is 70 wt %; the calcination is performed at 410° C. for 1.1 hours; the mass ratio of the composite support, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate, and ammonia water is 22:75:21:0.7:2.6:11; and the concentration of the ammonia water is 24%.

[0045] Example 4

[0046] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then calcining it at high temperature, and cooling it to room temperature;

[0047] In the treatment process, the screening is through a 60-mesh sieve; the mixing time is 38 minutes; and the high-temperature calcination treatment is calcination at 670° C. for 85 minutes.

[0048] The preparation method of the composite catalyst comprises the following steps:

[0049] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0050] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash three times with ethanol solution, vacuum dry and calcine to obtain a composite catalyst.

[0051] In step 1), the grinding and mixing is performed at a speed of 470 r / min for 55 minutes; the stirring and mixing time is 48 minutes; the heat treatment is performed at a temperature of 58°C and a speed of 650 r / min for 4.8 hours; the vacuum drying is performed at a temperature of 80°C to constant weight; and the calcination is performed at a temperature of 500°C for 3.8 hours. The mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is 8.8:0.08:0.35:34:3.4; and the coupling agent is a zirconium-aluminum coupling agent.

[0052] In step 2), the heating and stirring is performed at 200° C. for 2.4 hours; the concentration of the ethanol solution is 70 wt %; the calcination is performed at 415° C. for 1.2 hours; the mass ratio of the composite support, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate, and ammonia water is 23:78:21.5:0.75:2.7:11.5; and the concentration of the ammonia water is 24%.

[0053] Example 5

[0054] A treatment process for reducing the sulfur content of calcined petroleum coke comprises the following steps: grinding the petroleum coke, screening it, adding a composite catalyst, mixing it, and then calcining it at high temperature, and cooling it to room temperature;

[0055] In the treatment process, the screening is through a 60-mesh sieve; the mixing time is 40 minutes; and the high-temperature calcination treatment is calcination at 690° C. for 90 minutes.

[0056] The preparation method of the composite catalyst comprises the following steps:

[0057] Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier;

[0058] Step 2): After mixing the composite support, ethylene glycol and deionized water, add nickel nitrate hexahydrate and ammonium molybdate tetrahydrate, add ammonia water, heat and stir, cool to room temperature and then centrifuge, wash three times with ethanol solution, vacuum dry and calcine to obtain a composite catalyst.

[0059] In step 1), the grinding and mixing is performed at a speed of 500 r / min for 60 minutes; the stirring and mixing time is 50 minutes; the heat treatment is performed at a temperature of 60°C and a speed of 700 r / min for 5 hours; the vacuum drying is performed at a temperature of 80°C to constant weight; the calcination is performed at a temperature of 500°C for 4 hours; the mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is 9:0.08:0.4:35:3.4; and the coupling agent is a zirconium-aluminum coupling agent.

[0060] In step 2), the heating and stirring is performed at 200° C. for 2.5 hours; the concentration of the ethanol solution is 70wt%; the calcination is performed at 420° C. for 1.2 hours; the mass ratio of the composite support, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate, and ammonia water is 24:80:22:0.8:2.8:12; and the concentration of the ammonia water is 24%.

[0061] Comparative Example 1

[0062] Compared with Example 3, the difference in Comparative Example 1 is that light calcium carbonate is not used, and the other components, preparation steps and parameters are the same.

[0063] Comparative Example 2

[0064] Compared with Example 3, Comparative Example 2 is different in that mercaptosuccinic acid is not used, and the remaining components, preparation steps and parameters are the same.

[0065] Comparative Example 3

[0066] Compared with Example 3, Comparative Example 3 is different in that the coupling agent in step 1) is aluminate coupling agent DL-411, and the other components, preparation steps and parameters are the same.

[0067] Comparative Example 4

[0068] Compared with Example 3, Comparative Example 4 is different in that no coupling agent is used in step 1), and the remaining components, preparation steps and parameters are the same.

[0069] The desulfurization rates of the petroleum cokes of Examples 1-5 and Comparative Examples 1-4 were calculated, and the test results are shown in Table 1.

[0070] Desulfurization rate (%) = (sulfur content in raw materials - sulfur content in calcined products) / sulfur content in raw materials 100%.

[0071] Table 1

[0072] Desulfurization rate (%) Example 1 86.5 Example 2 89.1 Example 3 87.7 Example 4 86.2 Example 5 87.4 Comparative Example 1 75.8 Comparative Example 2 70.6 Comparative Example 3 67.3 Comparative Example 4 57.8

[0073] From the test results in Table 1, it can be seen that, compared with Comparative Examples 1-4, Examples 1-5 have a more significant desulfurization effect on petroleum coke through the treatment process of the present invention.

[0074] The present invention forms a composite by rectorite and calcium carbonate to increase the number of active hydroxyl groups, and then allows mercaptosuccinic acid to adhere to the composite on its surface by physical adsorption. The introduced mercapto groups can effectively improve the grafting rate of the composite to the zirconium-aluminum coupling agent. During the calcination process, the sulfur element of the mercaptosuccinic acid is easily oxidized at high temperature, accelerating the formation of aluminum / zirconium oxide while limiting the growth of grains through coordination, so that smaller particles of zirconium / aluminum oxide can be uniformly generated on the surface of the composite. Calcium carbonate prevents the pores of the composite carrier from being blocked, which is conducive to the formation of a porous structure of the composite carrier, thereby increasing the The specific surface area is increased, and the adsorption effect of the composite carrier is significantly improved, which is conducive to the removal of sulfur. Compared with the surface of the composite carrier, when zirconium oxide is compounded with aluminum oxide, the agglomeration phenomenon between the aluminum / zirconium oxide particles itself can be effectively reduced, so that aluminum oxide / zirconium oxide is evenly generated on the surface of the composite carrier. At the same time, the pore structure of the aluminum oxide / zirconium oxide layer can further increase the adsorption capacity of the composite carrier for active metal nickel / molybdenum. At the same time, the aluminum oxide / zirconium oxide layer can effectively increase the thermal stability of the rectorite, avoiding the collapse caused by excessive calcination activation or calcination desulfurization.

[0075] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for reducing the sulfur content of calcined petroleum coke, characterized in that: The treatment process comprises the following steps: grinding the petroleum coke, screening it, adding the composite catalyst, mixing it, and then calcining it, and then cooling it to complete the process; The preparation method of the composite catalyst comprises the following steps: Step 1): Grind and mix rectorite, light calcium carbonate and anhydrous ethanol, add mercaptosuccinic acid and stir to mix, add a coupling agent and mix well, then heat the mixture, filter the solid, vacuum dry and calcine to obtain a composite carrier; Step 2): After the composite support, ethylene glycol and deionized water are mixed, nickel nitrate hexahydrate and ammonium molybdate tetrahydrate are added, ammonia water is added, heated and stirred, cooled to room temperature and then centrifuged, washed with ethanol solution several times, vacuum dried and then calcined to obtain a composite catalyst; In step 1), the mass ratio of the rectorite, light calcium carbonate, mercaptosuccinic acid, anhydrous ethanol and coupling agent is (8-9): (0.06-0.08): (0.2-0.4): (30-35): (3.2-3.4); In step 2), the mass ratio of the composite carrier, ethylene glycol, deionized water, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate and ammonia water is 20-24:70-80:20-22:0.6-0.8:2.4-2.8:10-12.

2. A process for reducing the sulfur content of calcined petroleum coke according to claim 1, characterized in that: In the treatment process, the screening is to pass through a 50-100 mesh sieve; the mixing time is 30-40 minutes; and the calcination treatment is to calcine at 620-690° C. for 70-90 minutes.

3. A process for reducing the sulfur content of calcined petroleum coke according to claim 1, characterized in that: In step 1), the grinding and mixing is performed at a rotation speed of 400-500 r / min for 40-60 min; and the stirring and mixing time is 40-50 min.

4. A process for reducing the sulfur content of calcined petroleum coke according to claim 1, characterized in that: In step 1), the vacuum drying is performed at 80° C. to a constant weight; and the heating treatment is performed at 50-60° C. and 500-700 r / min with stirring for 4-5 hours.

5. The process for reducing the sulfur content of calcined petroleum coke according to claim 1, wherein: In step 1), the coupling agent is a zirconium-aluminum coupling agent; and the calcination is carried out at a temperature of 500° C. for 3-4 hours.

6. A process for reducing the sulfur content of calcined petroleum coke according to claim 1, characterized in that: In step 2), the heating and stirring is performed at 200° C. for 2.0-2.5 hours; and the concentration of the ethanol solution is 70 wt %.

7. The process for reducing the sulfur content of calcined petroleum coke according to claim 1, wherein: In step 2), the calcination is carried out at a temperature of 400-420° C. for 1.0-1.2 h.

8. The process for reducing the sulfur content of calcined petroleum coke according to claim 1, wherein: The concentration of the ammonia water is 24%.