Hydro-upgrading catalyst, its preparation method and application

Abstract

This invention discloses a hydrogenation and upgrading catalyst, its preparation method, and its application, belonging to the field of catalyst technology. The invention first pyrolyzes wheat straw into biochar, then mixes it with KOH and nitrides and calcines it to obtain nitrogen-doped biochar. The nitrogen-doped biochar is then mixed with a solution of cobalt nitrate and ammonium molybdate, dried, and calcined under nitrogen, followed by calcination under hydrogen to obtain a Co-Mo / NBC catalyst with Mo2C and Co3Mo3C as active components and nitrogen-doped activated biochar as the support. Because the nitrogen-doped activated biochar contains pyridine nitrogen as a coordination element for metallic Mo, Mo anchors pyridine nitrogen to form N-Mo, which promotes the dispersion of Mo2C and enhances the interaction between Mo2C and the nitrogen-doped biochar support. Furthermore, the addition of the promoter Co promotes Mo carburization, resulting in more Mo oxides forming Mo2C, and Co transfers electrons to Mo, making Mo electron-rich, significantly improving the hydrogenation activity of the catalyst. The catalyst maintains high desulfurization and denitrification rates even after at least seven reuses without any further treatment.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a hydrogenation upgrading catalyst, its preparation method, and its application. Background Technology

[0002] With the continuous development of the automotive industry, the number of motor vehicles worldwide has been increasing year by year, leading to a year-on-year increase in global tire production. Waste tires are difficult to degrade naturally, and improper disposal not only occupies a large amount of land resources but also causes serious environmental pollution and even endangers human health. Therefore, the "black pollution" problem caused by waste tires is becoming increasingly serious and urgently needs to be addressed.

[0003] Pyrolysis is considered one of the important technologies for waste tire disposal. Wt-Temperature pyrolysis oil (WTPO) is the most valuable product from waste tire pyrolysis, possessing a high calorific value and potential as a substitute for traditional fuels. However, due to the addition of vulcanizing agents and accelerators during tire manufacturing, waste tire pyrolysis oil contains a significant amount of sulfides and nitrogen oxides, limiting its direct use. Furthermore, the presence of unsaturated compounds in the oil reduces the oxidative and photothermal stability of WTPO, potentially leading to a darker color. Therefore, it is essential to reduce the content of olefins, sulfur and nitrogen compounds, and polyaromatics in WTPO to improve its value. Hydrotreating not only achieves hydrogenation, desulfurization, and denitrification of olefins and aromatics but also reduces oil density and increases the hydrogen / carbon ratio, making it an important method for cleaning up low-quality oil products. The key to hydrotreating and upgrading WTPO lies in the development of highly active catalysts.

[0004] Currently, catalysts used for the hydrotreating of waste tire pyrolysis oil include MoS2, Ni-WS2, and Ni / Co-MoS2. Although pre-sulfurization treatment can improve the hydrodesulfurization activity of the catalyst, the pre-sulfurization process generates sulfur pollution, causing environmental harm. While precious metal catalysts (platinum, palladium, rhodium, etc.) have good hydrotreating effects, they are expensive, have poor sulfur resistance and coking resistance, and are prone to deactivation. Molybdenum carbide, known as a "platinum-like catalyst," is becoming a new type of hydrotreating catalyst due to its unique electronic properties and excellent hydrotreating catalytic activity. Replacing Pt catalysts with Mo2C can significantly reduce catalyst costs. The promoter Co can synergistically interact with Mo2C to promote the hydrodesulfurization and denitrification reactions. However, bimetallic catalysts are prone to self-aggregation and surface oxidation at high temperatures, limiting their catalytic activity.

[0005] The chemical composition and physical structure of the catalyst support affect the catalyst's performance. The interaction between the support and the active phase influences the catalyst's activity. Al₂O₃, due to its high porosity, large specific surface area, and good stability, is commonly used as a support for hydrotreating catalysts in the oil refining industry. However, the excessively strong interaction between Al₂O₃ and the active component prevents the active component (Mo) from completely converting from the oxidized state to the sulfidized state during the catalyst pre-sulfurization process, resulting in a decrease in its hydrodesulfurization activity. Carbon, due to its inert surface, can weaken the interaction between the catalyst and the support, making its HDS activity higher than that of Al₂O₃. However, the weak interaction also makes the active component prone to leaching and aggregation, affecting catalytic activity. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a hydrogenation upgrading catalyst, its preparation method, and its application.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0009] (1) Wheat straw was calcined to obtain biochar, then KOH and nitrogen compounds were added and mixed evenly and calcined under an inert gas. Finally, the mixture was washed and dried to obtain nitrogen-doped biochar.

[0010] (2) Nitrogen-doped biochar was immersed in a solution of cobalt and molybdenum salts, stirred, sonicated, and dried, and then calcined under nitrogen. After cooling, it was calcined under hydrogen to obtain a hydrogenation and upgrading catalyst.

[0011] In a preferred embodiment of the present invention, the mass ratio of biochar, KOH and nitride is 1:2-3:0.16-0.17.

[0012] As a preferred embodiment of the present invention, in step (1), the temperature of wheat straw calcination is 700-900℃, the time is 1-3h, and the heating rate is 10-40℃ / min.

[0013] As a preferred embodiment of the present invention, in step (1), the calcination temperature under inert gas is 800-900℃, the time is 1-3h, the heating rate is 10-40℃ / min, and the flow rate of inert gas is 30-80mL / min.

[0014] The inert gas is one of nitrogen, argon, or helium.

[0015] As a preferred embodiment of the present invention, in step (2), the mass of Co in the cobalt salt is 1-7% of the mass of nitrogen-doped biochar, and the mass of Mo in the molybdenum salt is 5-10% of the mass of nitrogen-doped biochar.

[0016] In a preferred embodiment of the present invention, the ultrasound time in step (2) is 30 min to 1 h.

[0017] As a preferred embodiment of the present invention, in step (2), the calcination temperature under nitrogen is 500-700℃, the time is 1-4h, the heating rate is 10-40℃ / min, and the flow rate of inert gas is 30-80mL / min.

[0018] As a preferred embodiment of the present invention, in step (2), the calcination temperature under hydrogen is 500-800℃, the time is 3-6h, the heating rate is 10-40℃ / min, and the hydrogen flow rate is 20-60mL / min.

[0019] In a preferred embodiment of the present invention, the nitride is at least one of melamine, urea, and dicyandiamide; the cobalt salt is cobalt nitrate hexahydrate, and the molybdenum salt is ammonium molybdate tetrahydrate.

[0020] The present invention also claims protection for the hydrogenation upgrading catalyst prepared by the method described above.

[0021] This invention also claims protection for the application of the said hydrotreating catalyst in the hydrotreating of waste tire pyrolysis oil.

[0022] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention uses biochar, nitrides, cobalt nitrate, and ammonium molybdate as main raw materials to obtain a Co-Mo / NBC catalyst with Mo2C and Co3Mo3C as active components and nitrogen-doped activated biochar as a support. Because the nitrogen-doped activated biochar contains pyridine nitrogen as a coordination element for metallic Mo, Mo anchors pyridine nitrogen to form N-Mo, which promotes the dispersion of Mo2C and enhances the interaction between Mo2C and the nitrogen-doped biochar support. Furthermore, the addition of Co, in synergistic with N, promotes the carburization of Mo to generate more Mo2C, and the transfer of electrons from Co to Mo enriches Mo with electrons, significantly improving the hydrogenation activity of the catalyst. The catalyst can maintain high desulfurization and denitrification rates even after at least seven reuses without any treatment. Attached Figure Description

[0023] Figure 1 The images show the physical composition, chromatogram, and composition diagram of waste tire pyrolysis oil.

[0024] Figure 2 This is a flowchart illustrating the preparation process of a hydrogenation and upgrading catalyst.

[0025] Figure 3 XPS N1s images of biochar BC and nitrogen-doped biochar NBC prepared in Example 1.

[0026] Figure 4The images show the XRD patterns of the hydrogenation catalysts prepared in Example 1 and Comparative Examples 1-3.

[0027] Figure 5 The images show the physical composition, chromatogram, and material composition diagram of the waste tire pyrolysis oil after hydrogenation and upgrading using the hydrogenation catalyst prepared in Example 1.

[0028] Figure 6 The following are examples of the repeated use stability of the hydrogenation upgrading catalyst prepared in Example 1 for hydrogenation upgrading of waste tire pyrolysis oil: (a) is a comparison chart of desulfurization rate and denitrification rate after seven cycles; (b) is a comparison chart of the content of each component in waste tire pyrolysis oil after seven cycles of hydrogenation upgrading; (c) is a comparison chart of the actual waste tire pyrolysis oil after seven cycles of hydrogenation upgrading.

[0029] Figure 7 The above are H2-TPR diagrams of the hydrogenation upgrading catalysts prepared in Example 1 and Comparative Examples 1-2. Detailed Implementation

[0030] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0031] Example 1

[0032] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0033] (1) Wheat straw was calcined at 750℃ for 1h to obtain biochar BC, with a heating rate of 30℃ / min.

[0034] (2) Take 10g of biochar BC, 20g of KOH and 1.67g of melamine and mix them evenly. Calcine them at 800℃ for 1h under nitrogen gas. The heating rate is 20℃ / min and the flow rate of nitrogen gas is 50mL / min. After cooling to room temperature, wash with deionized water until neutral and dry at 105℃ to obtain nitrogen-doped biochar NBC.

[0035] (3) Cobalt nitrate hexahydrate and ammonium molybdate tetrahydrate were mixed and dissolved in deionized water to make a solution. Then nitrogen-doped biochar NBC was added. The mass of Co in the cobalt salt was 3% of the mass of the nitrogen-doped biochar, and the mass of Mo in the molybdenum salt was 10% of the mass of the nitrogen-doped biochar. The mixture was sonicated for 30 min and then dried at 105 °C until the solvent evaporated to obtain NBC loaded with active ingredients.

[0036] (4) Then, the NBC loaded with active components was placed in a tube furnace and calcined at 500°C under a nitrogen atmosphere for 3 h to obtain the oxides of Co and Mo. The heating rate was 20°C / min and the flow rate of nitrogen gas was 30 mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 700°C for 4 h to obtain the 3Co-10Mo / NBC catalyst. The calcination heating rate was 10°C / min and the flow rate of hydrogen gas was 40 mL / min.

[0037] Example 2

[0038] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0039] (1) Wheat straw was calcined at 700℃ for 2h to obtain biochar BC, with a heating rate of 10℃ / min.

[0040] (2) Take 10g of biochar BC, 30g of KOH and 1.6g of melamine and mix them evenly. Calcine them at 900℃ for 3h under nitrogen gas. The heating rate is 40℃ / min and the flow rate of nitrogen gas is 30mL / min. After cooling to room temperature, wash with deionized water until neutral and dry at 105℃ to obtain nitrogen-doped biochar NBC.

[0041] (3) Mix cobalt nitrate hexahydrate and ammonium molybdate tetrahydrate and dissolve them in deionized water to make a solution. Then add nitrogen-doped biochar NBC. The mass of Co in the cobalt salt is 1% of the mass of nitrogen-doped biochar, and the mass of Mo in the molybdenum salt is 5% of the mass of nitrogen-doped biochar. Sonicate for 1 hour, and then dry at 105°C until the solvent evaporates to obtain NBC loaded with active ingredients.

[0042] (4) Then, the NBC loaded with active components was placed in a tube furnace and calcined at 500°C under a nitrogen atmosphere for 1 h to obtain the oxides of Co and Mo. The heating rate was 30°C / min and the flow rate of nitrogen gas was 50 mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 800°C for 3 h to obtain the 1Co-5Mo / NBC catalyst. The calcination heating rate was 40°C / min and the flow rate of hydrogen gas was 20 mL / min.

[0043] Example 3

[0044] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0045] (1) Wheat straw was calcined at 900℃ for 3h to obtain biochar BC, with a heating rate of 40℃ / min.

[0046] (2) Take 10g of biochar BC, 20g of KOH and 1.7g of melamine and mix them evenly. Calcine them at 800℃ for 1h under nitrogen gas. The heating rate is 20℃ / min and the flow rate of nitrogen gas is 50mL / min. After cooling to room temperature, wash with deionized water until neutral and dry at 105℃ to obtain nitrogen-doped biochar NBC.

[0047] (3) Cobalt nitrate hexahydrate and ammonium molybdate tetrahydrate were mixed and dissolved in deionized water to make a solution. Then nitrogen-doped biochar NBC was added. The mass of Co in the cobalt salt was 7% of the mass of nitrogen-doped biochar, and the mass of Mo in the molybdenum salt was 10% of the mass of nitrogen-doped biochar. The mixture was sonicated for 1 hour and then dried at 105°C until the solvent evaporated to obtain NBC loaded with active ingredients.

[0048] (4) Then, the NBC loaded with active components was placed in a tube furnace and calcined at 700°C under a nitrogen atmosphere for 4 h to obtain the oxides of Co and Mo. The heating rate was 10°C / min and the flow rate of nitrogen gas was 80 mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 500°C for 6 h to obtain the 7Co-10Mo / NBC catalyst. The calcination heating rate was 10°C / min and the flow rate of hydrogen gas was 60 mL / min.

[0049] Comparative Example 1

[0050] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0051] (1) Wheat straw was calcined at 750℃ for 1h to obtain biochar BC, with a heating rate of 30℃ / min.

[0052] (2) Cobalt nitrate hexahydrate and ammonium molybdate tetrahydrate were mixed and dissolved in deionized water to make a solution. Then biochar BC was added. The mass of Co in the cobalt salt was 3% of the mass of the biochar, and the mass of Mo in the molybdenum salt was 10% of the mass of the biochar. The mixture was sonicated for 30 min and then dried at 105 °C until the solvent evaporated to obtain BC loaded with active ingredients.

[0053] (3) Then, the BC loaded with active components was placed in a tube furnace and calcined at 500℃ under a nitrogen atmosphere for 3h to obtain the oxides of Co and Mo. The heating rate was 40℃ / min and the flow rate of nitrogen gas was 30mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 700℃ for 4h to obtain the 3Co-10Mo / BC catalyst. The calcination heating rate was 10℃ / min and the flow rate of hydrogen gas was 40mL / min.

[0054] Comparative Example 2

[0055] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0056] (1) Wheat straw was calcined at 750℃ for 1h to obtain biochar BC, with a heating rate of 30℃ / min.

[0057] (2) Take 10g of biochar BC, 20g of KOH and 1.67g of melamine and mix them evenly. Calcine them at 800℃ for 1h under nitrogen gas. The heating rate is 20℃ / min and the flow rate of nitrogen gas is 50mL / min. After cooling to room temperature, wash with deionized water until neutral and dry at 105℃ to obtain nitrogen-doped biochar NBC.

[0058] (3) Dissolve ammonium molybdate tetrahydrate in deionized water to make a solution, then add nitrogen-doped biochar NBC, the mass of Mo in the molybdenum salt is 10% of the mass of nitrogen-doped biochar, sonicate for 30 min, and then dry at 105 °C until the solvent evaporates to obtain NBC loaded with active ingredients.

[0059] (4) Then, the NBC loaded with active components was placed in a tube furnace and calcined at 500°C under a nitrogen atmosphere for 3 hours to obtain the oxide state of Mo. The heating rate was 40°C / min and the flow rate of nitrogen gas was 30 mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 700°C for 5 hours to obtain the 10Mo / NBC catalyst. The calcination heating rate was 10°C / min and the flow rate of hydrogen gas was 40 mL / min.

[0060] Comparative Example 3

[0061] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0062] (1) Wheat straw was calcined at 750℃ for 1h to obtain biochar BC, with a heating rate of 30℃ / min.

[0063] (2) Take 10g of biochar BC, 20g of KOH and 1.67g of melamine and mix them evenly. Calcine them at 800℃ for 1h under nitrogen gas. The heating rate is 20℃ / min and the flow rate of nitrogen gas is 50mL / min. After cooling to room temperature, wash with deionized water until neutral and dry at 105℃ to obtain nitrogen-doped biochar NBC.

[0064] (3) Dissolve cobalt nitrate hexahydrate in deionized water to make a solution, then add nitrogen-doped biochar NBC, the mass of Co in the cobalt salt is 3% of the mass of nitrogen-doped biochar, sonicate for 30 min, and then dry at 105 °C until the solvent evaporates to obtain NBC loaded with active ingredients.

[0065] (4) Then, the NBC loaded with active ingredients was placed in a tube furnace and calcined at 500°C under a nitrogen atmosphere for 3 hours to obtain the oxide state of Co. The heating rate was 40°C / min and the flow rate of nitrogen gas was 30 mL / min. After cooling to room temperature, the carrier gas was switched to hydrogen and calcined at 700°C for 4 hours to obtain the 3Co / NBC catalyst. The calcination heating rate was 10°C / min and the flow rate of hydrogen gas was 40 mL / min.

[0066] Comparative Example 4

[0067] A method for preparing a hydrogenation upgrading catalyst includes the following steps:

[0068] (1) Wheat straw was calcined at 750℃ for 1h to obtain biochar BC, with a heating rate of 30℃ / min.

[0069] (2) Take 10g of biochar BC, mix it with 20g of KOH and 1.67g of melamine, and calcine it at 800℃ for 1h under nitrogen gas. The heating rate is 20℃ / min and the flow rate of nitrogen gas is 50mL / min. After cooling to room temperature, wash it with deionized water until neutral, and dry it at 105℃ to obtain nitrogen-doped biochar NBC.

[0070] Example 1

[0071] The materials prepared in Examples 1-3 and Comparative Examples 1-6 were subjected to hydrogenation and upgrading of waste tire pyrolysis oil. Specifically, this included: weighing 0.3g of catalyst and placing it in a high-pressure reactor; and using genuine waste tire pyrolysis oil (composition as follows) from a tire pyrolysis company in Yunnan Province. Figure 1 2g of raw material (as shown) was added to the high-pressure reactor, and then N2 (100mL / min) was introduced to purge for 10min to remove residual air from the reactor. H2 was then introduced and the pressure increased to 3MPa, with a stirring rate of 300r / min. The reactor was then heated to 330℃ at a rate of 10℃ / min, and held at this temperature for 6h after stabilization. After the reaction was complete, the reactor was removed and cooled in an ice-water bath. The reactor was repeatedly cleaned with tetrahydrofuran, filtered through a sand core funnel, and the tetrahydrofuran was removed by rotary evaporation to obtain hydrogenated waste tire pyrolysis oil. The composition of the hydrogenated oil was determined by Py-GC / MS, and sulfur and nitrogen in the oil were analyzed using a sulfur-nitrogen detector (JF-TSN-6000).

[0072] The hydrodesulfurization rate (%) of waste tire pyrolysis oil is:

[0073]

[0074] Rs——Removal rate of sulfur in waste tire pyrolysis oil (unit: %);

[0075] S1—S content in waste tire pyrolysis oil;

[0076] S2 – The sulfur content in waste tire pyrolysis oil after hydrotreating.

[0077] Table 1

[0078] Desulfurization rate (%) Nitrogen removal rate (%) Example 1 99.1 63.9 Example 2 88.2 53.6 Example 3 94.1 66.2 Comparative Example 1 48.0 29.3 Comparative Example 2 69.8 26.2 Comparative Example 3 23.1 8.7 Comparative Example 4 3.8 1.2 Catalyst-free 2.2 0.6

[0079] As shown in Table 1, based on Example 1 and Comparative Example 1, the Co-Mo supported on biochar BC without nitrogen doping and potassium hydroxide activation exhibits weaker interactions between biochar BC and Co and Mo, leading to easy leaching and aggregation of the active components Co and Mo. This results in low catalytic hydrogenation activity, with both desulfurization and denitrification rates being relatively low. Furthermore, due to... Figure 3 It is known that the 3Co-10Mo / NBC catalyst of this invention, after nitrogen doping activation, contains abundant pyridine nitrogen, which can be used as a coordination agent for metallic Mo. Mo anchors pyridine nitrogen to form N-Mo, promoting Mo dispersion and enhancing the interaction between Mo and the nitrogen-doped carbon support, thereby improving the catalyst's catalytic hydrogenation activity. Figure 5 As can be seen, the color of the waste tire pyrolysis oil after catalytic hydrotreating with 3Co-10Mo / NBC turns dark yellow, which is similar to the color of the waste tire pyrolysis oil. Figure 1 The significant changes compared to the previous data indicate that catalytic hydrotreating effectively removes color-producing substances from waste tire pyrolysis oil. The chromatogram and composition of the hydrotreated oil show that catalytic hydrotreating significantly reduces sulfides, nitrogen oxides, and olefins, while increasing alkanes and cycloalkanes. This contributes to improved oil stability and antioxidant properties, thereby enhancing the oil's value.

[0080] Depend on Figure 4 As can be seen from Examples 1 and Comparative Examples 2-3, the additive Co promotes the carburizing reaction of Mo, which converts more Mo oxides into Mo2C and generates more reactive centers; moreover, Co interacts with Mo to generate Co3Mo3C, and Co transfers electrons to Mo, making Mo electron-rich and significantly improving the hydrogenation activity of the catalyst.

[0081] As can be seen from Example 1 and Comparative Example 4, nitrogen-doped biochar NBC does not have hydrogenation activity, and its structure does not directly support the active sites or catalytic mechanisms required for hydrogenation reactions.

[0082] Compared to the one-step calcination of melamine, potassium hydroxide, and wheat straw to directly obtain nitrogen-doped biochar, this invention first prepares biochar through calcination, and then adds melamine and potassium hydroxide for calcination to obtain nitrogen-doped biochar. This overcomes the limitations of wheat straw due to its complexity, which prevents melamine and potassium hydroxide from interacting uniformly with the straw, resulting in poor nitrogen doping in the formed support and consequently, poor catalyst activity. Directly calcining NBC loaded with active components in a tube furnace with hydrogen causes a decrease in catalyst activity. This is because impurities such as molybdenum salt precursors in the biochar affect the molybdenum carburizing reaction, leading to uneven distribution of the generated active metal. Furthermore, changes in the pore structure of the biochar further affect the loading of the active metal.

[0083] Example 2

[0084] The material prepared in Example 1 was subjected to hydrogenation and upgrading of waste tire pyrolysis oil. Specifically, 0.3g of catalyst was weighed and placed in a high-pressure reactor, and real waste tire pyrolysis oil (composition as follows) from a tire pyrolysis company in Yunnan Province was selected. Figure 1 2g of raw material (as shown) was added to the high-pressure reactor, and then N2 (100mL / min) was introduced to purge for 10min to remove residual air from the reactor. H2 was then introduced and the pressure increased to 6MPa, with a stirring rate of 300r / min. The reactor was then heated to 330℃ at a rate of 10℃ / min, and held at this temperature for 6h after stabilization. After the reaction was complete, the reactor was removed and cooled in an ice-water bath. The reactor was repeatedly cleaned with tetrahydrofuran, filtered through a sand core funnel, and the tetrahydrofuran was removed by rotary evaporation to obtain hydrogenated waste tire pyrolysis oil. The composition of the hydrogenated oil was determined by Py-GC / MS, and sulfur and nitrogen in the oil were analyzed using a sulfur-nitrogen detector (JF-TSN-6000). During catalyst recycling, the catalyst material filtered through the sand core funnel was dried, weighed, and added to the high-pressure reactor. Subsequent experimental steps were the same as above. The yields of the three-phase products obtained after catalyst reuse are shown in Table 2.

[0085] Table 2

[0086] Serial Number Liquid (wt.%) Solid (wt.%) Gas (wt.%) Run1 89.69 0.59 9.72 Run2 91.95 0.02 8.03 Run3 90.18 0.37 9.45 Run4 91.85 0.75 7.40 Run5 90.45 0.41 9.14 Run6 90.65 0.39 8.96 Run7 91.17 0.29 8.54

[0087] according to Figure 6 It can be seen that the Co-Mo / NBC catalyst in Example 1 can maintain a high desulfurization and denitrification rate even after at least 7 reuses without any treatment, and the yield of the hydrotreated waste tire pyrolysis oil remains above 89.69 wt.%, indicating a high oil yield. Furthermore, according to... Figure 4 It can be seen that after seven cycles, the phase composition of the Co-Mo / NBC catalyst remained unchanged. From... Figure 7It can be seen that the second reduction peak of Co-Mo / NBC exhibits a higher temperature (542℃→521℃) compared to Mo / NBC, indicating that the addition of the promoter Co enhances the interaction force between the catalyst and the support, which is beneficial to enhancing the stability of the catalyst. The second reduction peak of Co-Mo / NBC exhibits a higher temperature (512℃→496℃) compared to Co-Mo / BC, indicating that nitrogen doping enhances the interaction force between the catalyst and the support, making Co-Mo / NBC more stable than Co-Mo / BC.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a catalyst for the hydrotreating and upgrading of waste tire pyrolysis oil, characterized in that, Includes the following steps: (1) Wheat straw was calcined to obtain biochar, then KOH and nitrogen compounds were added and mixed evenly and calcined under an inert gas, and finally washed and dried to obtain nitrogen-doped biochar; (2) Nitrogen-doped biochar was immersed in a solution of cobalt salt and molybdenum salt, stirred, sonicated, dried, and then calcined under nitrogen. After cooling, it was calcined under hydrogen to obtain a hydrogenation and upgrading catalyst. In step (2), the calcination temperature under hydrogen is 500-800℃, the time is 3-6h, the heating rate is 10-40℃ / min, and the hydrogen flow rate is 20-60mL / min. The nitride is at least one of melamine, urea, and dicyandiamide.

2. The preparation method of the hydrogenation upgrading catalyst as described in claim 1, characterized in that, The mass ratio of biochar, KOH, and nitrogen oxides is 1:2-3:0.16-0.

17.

3. The preparation method of the hydrogenation upgrading catalyst as described in claim 1, characterized in that, In step (1), the temperature of wheat straw calcination is 700-900℃, the time is 1-3h, and the heating rate is 10-40℃ / min.

4. The preparation method of the hydrogenation upgrading catalyst as described in claim 1, characterized in that, In step (1), the calcination temperature under inert gas is 800-900℃, the time is 1-3h, the heating rate is 10-40℃ / min, and the flow rate of inert gas is 30-80mL / min.

5. The method for preparing the hydrogenation upgrading catalyst as described in claim 1, characterized in that, In step (2), the mass of Co in the cobalt salt is 1-7% of the mass of nitrogen-doped biochar, and the mass of Mo in the molybdenum salt is 5-10% of the mass of nitrogen-doped biochar.

6. The method for preparing the hydrogenation upgrading catalyst as described in claim 1, characterized in that, In step (2), the calcination temperature under nitrogen is 500-700℃, the time is 1-4h, the heating rate is 10-40℃ / min, and the flow rate of inert gas is 30-80mL / min.

7. The preparation method of the hydrogenation upgrading catalyst according to claim 1, characterized in that, The cobalt salt is cobalt nitrate hexahydrate, and the molybdenum salt is ammonium molybdate tetrahydrate.

8. The hydrogenation catalyst prepared by the method of any one of claims 1-7.

9. The application of the hydrotreating catalyst according to claim 8 in the hydrotreating of waste tire pyrolysis oil.

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