Hydrogenation upgrading catalyst as well as preparation method and application thereof

Abstract

The invention discloses a hydrogenation upgrading catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. The preparation method comprises the following steps: firstly, pyrolyzing wheat straws into biochar, then mixing and calcining with KOH and nitride to obtain nitrogen-doped biochar, mixing and drying the nitrogen-doped biochar with cobalt nitrate and an ammonium molybdate solution, then calcining in nitrogen, and then calcining in hydrogen to obtain the Co-Mo / NBC catalyst which takes Mo2C and Co3Mo3C as active components and takes the nitrogen-doped activated biochar as a carrier. The nitrogen-doped activated charcoal contains pyridine nitrogen as a coordination of metal Mo, and Mo anchors the pyridine nitrogen to form N-Mo, so that the dispersion of Mo2C can be promoted, and the interaction between Mo2C and the nitrogen-doped charcoal carrier is enhanced. In addition, Mo carburization can be promoted by adding the auxiliary Co, so that more Mo oxides can generate Mo2C, and Co transfers electrons to Mo, so that Mo is rich in electrons, the hydrogenation activity of the catalyst is remarkably improved, and the catalyst can still keep higher desulfurization rate and denitrification rate in at least seven times of repeated use without any treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and specifically relates to a hydrogenation upgrading catalyst and a preparation method and application thereof. Background Art

[0002] With the continuous development of the automobile industry, the number of motor vehicles in the world has increased year by year, resulting in an increase in global tire production. Waste tires are difficult to degrade naturally. If they are not properly disposed of, they will not only occupy a large amount of land resources, but also cause serious pollution to the environment and even endanger human health. Therefore, the "black pollution" problem caused by waste tires is becoming increasingly serious and needs to be solved urgently.

[0003] Pyrolysis is considered to be one of the important technologies for waste tire disposal. Pyrolysis oil (WTPO) is the most valuable product from waste tire pyrolysis. It has a high calorific value and has the potential to be a substitute for traditional fuels. However, due to the addition of vulcanizers and accelerators during the tire manufacturing process, waste tire pyrolysis oil contains more sulfides and nitrides, which limits its direct use. In addition, the presence of unsaturated compounds in the oil makes the oxidative stability and photothermal stability of WTPO worse, which may cause the color of WTPO to deepen. Therefore, it is necessary to reduce the content of olefins, S and N compounds, and polyaromatic hydrocarbons in WTPO to increase the value of WTPO. Hydrogenation treatment can not only achieve hydrogenation, desulfurization and denitrification of olefins and aromatics, but also reduce the density of oil products and increase the hydrogen / carbon ratio. It is an important treatment method for cleaning inferior oil products. The key to hydrogenation and upgrading of WTPO lies in the development of highly active catalysts.

[0004] The catalysts currently used for the hydrotreatment of waste tire pyrolysis oil are MoS2, Ni-WS2, Ni / Co-MoS2, etc. Although pre-sulfurization of the catalyst can improve the hydrodesulfurization activity of the catalyst, the pre-sulfurization process will produce sulfur pollution, causing harm to the environment. Although precious metal catalysts (platinum, palladium, rhodium, etc.) have good hydrotreatment effects, precious metals are expensive, have poor sulfur resistance and anti-coking properties, and are easily deactivated. Molybdenum carbide is known as a "platinum-like catalyst". Due to its unique electronic properties and excellent hydrogenation catalytic activity, it is becoming a new type of hydrogenation catalyst. Replacing Pt catalyst with Mo2C can significantly reduce the cost of the catalyst. The additive Co can produce a synergistic effect with Mo2C to promote the hydrodesulfurization and denitrification reactions. However, bimetallic catalysts under high temperature environments are prone to self-aggregation and surface oxidation, which restricts their catalytic activity.

[0005] The chemical composition and physical structure of the catalyst carrier affect the performance of the catalyst. The interaction between the carrier and the active phase affects the activity of the catalyst. Al2O3 is often used as a carrier for hydroprocessing catalysts in the oil refining industry because of its high porosity, large specific surface area and good stability. However, due to the strong interaction between Al2O3 and the active component, the active component (Mo) cannot be completely converted from the oxidized state to the sulfided state during the presulfurization of the catalyst, resulting in a decrease in its hydrodesulfurization activity. Because the surface of carbon is inert, it can weaken the interaction between the catalyst and the carrier, making its HDS activity higher than that of Al2O3, but because of the weak interaction, the active component is easy to leach and aggregate, affecting the catalytic activity. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a hydrogenation upgrading catalyst and a preparation method and application thereof.

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

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

[0009] (1) calcining wheat straw to obtain biochar, then adding KOH and nitride to mix evenly and calcining under inert gas, and finally washing and drying to obtain nitrogen-doped biochar;

[0010] (2) The nitrogen-doped biochar is immersed in a cobalt salt and molybdenum salt solution, stirred, ultrasonicated, and dried, and then calcined under nitrogen. After cooling, the biochar is calcined under hydrogen to obtain a hydrogenation catalyst.

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

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

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

[0014] The inert gas is one of nitrogen, argon and 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 the nitrogen-doped biochar, and the mass of Mo in the molybdenum salt is 5-10% of the mass of the nitrogen-doped biochar.

[0016] As a preferred embodiment of the present invention, in the step (2), the ultrasonication time is 30 min-1 h.

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

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

[0019] As 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 hydro-upgrading catalyst prepared by the preparation method of the hydro-upgrading catalyst.

[0021] The present invention also claims to protect the use of the hydrogenation upgrading catalyst in the hydrogenation upgrading of waste tire pyrolysis oil.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention uses biochar, nitride, 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 carrier. Because the nitrogen-doped activated biochar contains pyridinic nitrogen as a coordination of metal Mo, Mo anchors pyridinic nitrogen to form N-Mo, which can promote the dispersion of Mo2C and enhance the interaction between Mo2C and the nitrogen-doped biochar carrier. In addition, Co is added to promote the carburization of Mo in synergy with N to generate more Mo2C, and Co transfers electrons to Mo, making Mo electron-rich, which significantly improves the hydrogenation activity of the catalyst. The catalyst does not need to be treated in any way and can still maintain a high desulfurization rate and denitrification rate in at least 7 repeated uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the physical picture, chromatogram and material composition diagram of waste tire pyrolysis oil.

[0024] Figure 2 This is a flow chart for the preparation of hydrogenation upgrading catalyst.

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

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

[0027] Figure 5 The actual picture, chromatogram and material composition diagram of the waste tire pyrolysis oil after the waste tire pyrolysis oil was hydrogenated and upgraded by the hydrogenation and upgrading catalyst prepared in Example 1.

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

[0029] Figure 7 It is the H2-TPR diagram of the hydrogenation upgrading catalyst prepared in Example 1 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0030] In order to better illustrate the purpose, technical solutions 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 catalyst comprises the following steps:

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

[0034] (2) Take 10g of biochar BC, 20g of KOH and 1.67g of melamine, mix them evenly and calcine them at 800℃ for 1h under nitrogen gas, with a heating rate of 20℃ / min and a nitrogen gas flow rate of 50mL / min. After cooling to room temperature, wash them with deionized water until they are neutral, and dry them 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 prepare a solution, and 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. Ultrasonic treatment was performed for 30 minutes, and then dried at 105°C until the solvent evaporated to obtain NBC loaded with active ingredients.

[0036] (4) The NBC loaded with active ingredients was then placed in a tubular furnace and calcined at 500°C in a nitrogen atmosphere for 3 h to obtain the oxide state 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 catalyst comprises the following steps:

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

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

[0041] (3) Cobalt nitrate hexahydrate and ammonium molybdate tetrahydrate were mixed and dissolved in deionized water to prepare a solution, and then nitrogen-doped biochar NBC was added, with the mass of Co in the cobalt salt being 1% of the mass of the nitrogen-doped biochar, and the mass of Mo in the molybdenum salt being 5% of the mass of the nitrogen-doped biochar. The solution was ultrasonicated for 1 h and then dried at 105°C until the solvent evaporated to obtain NBC loaded with active ingredients.

[0042] (4) The NBC loaded with active ingredients was then placed in a tubular furnace and calcined at 500°C in a nitrogen atmosphere for 1 h to obtain the oxide state 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 catalyst comprises the following steps:

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

[0046] (2) Take 10g of biochar BC, 20g of KOH and 1.7g of melamine, mix them evenly and calcine them at 800℃ for 1h under nitrogen gas, with a heating rate of 20℃ / min and a nitrogen gas flow rate of 50mL / min. After cooling to room temperature, wash them with deionized water until they are neutral, and dry them 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 prepare a solution, and then nitrogen-doped biochar NBC was added, with the mass of Co in the cobalt salt being 7% of the mass of the nitrogen-doped biochar, and the mass of Mo in the molybdenum salt being 10% of the mass of the nitrogen-doped biochar. The mixture was ultrasonicated for 1 h and then dried at 105°C until the solvent evaporated to obtain NBC loaded with active ingredients.

[0048] (4) The NBC loaded with active ingredients was then placed in a tubular furnace and calcined at 700°C in a nitrogen atmosphere for 4 h to obtain the oxide state 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 catalyst comprises the following steps:

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

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

[0053] (3) The BC loaded with active ingredients was then placed in a tubular furnace and calcined at 500°C in a nitrogen atmosphere for 3 h to obtain the oxide state of Co and 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 4 h to obtain the 3Co-10Mo / BC catalyst. The calcination heating rate was 10°C / min and the flow rate of hydrogen gas was 40 mL / min.

[0054] Comparative Example 2

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

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

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

[0058] (3) Ammonium molybdate tetrahydrate was dissolved in deionized water to prepare a solution, and then nitrogen-doped biochar NBC was added, wherein the mass of Mo in the molybdenum salt was 10% of the mass of the nitrogen-doped biochar, and the solution was ultrasonicated for 30 min, and then dried at 105° C. until the solvent evaporated, thereby obtaining NBC loaded with active ingredients.

[0059] (4) The NBC loaded with active ingredients was then placed in a tubular furnace and calcined at 500°C in a nitrogen atmosphere for 3 h 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 h to obtain a 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 catalyst comprises the following steps:

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

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

[0064] (3) Cobalt nitrate hexahydrate was dissolved in deionized water to prepare a solution, and then nitrogen-doped biochar NBC was added, with the mass of Co in the cobalt salt being 3% of the mass of the nitrogen-doped biochar. The solution was ultrasonicated for 30 min and then dried at 105° C. until the solvent evaporated to obtain NBC loaded with active ingredients.

[0065] (4) The NBC loaded with active ingredients was then placed in a tubular furnace and calcined at 500°C in a nitrogen atmosphere for 3 h 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 h to obtain a 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 catalyst comprises the following steps:

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

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

[0070] Effect Example 1

[0071] The materials prepared in Examples 1-3 and Comparative Examples 1-6 were subjected to waste tire pyrolysis oil hydrogenation and upgrading, specifically comprising: weighing 0.3 g of catalyst and placing it in a high-pressure reactor; selecting real waste tire pyrolysis oil (components such as Figure 1 2g of 1,2-tetrahydrofuran (as shown) was also added to the autoclave as the raw material, and then N2 (100mL / min) was introduced to purge for 10min to remove the residual air in the autoclave, and then H2 was introduced and pressurized to 3MPa, with a stirring rate of 300r / min, and then the autoclave was heated to 330℃ at a heating rate of 10℃ / min, and kept warm for 6h after the temperature stabilized. After the reaction was completed, the reactor was taken out and cooled in an ice-water bath. The reactor was repeatedly cleaned with tetrahydrofuran, filtered with a sand core funnel, and the tetrahydrofuran was removed by rotary evaporation to obtain the hydrogenated waste tire pyrolysis oil. The material composition of the hydrogenated oil was detected by Py-GC / MS, and the sulfur and nitrogen in the hydrotreated oil were analyzed by a sulfur-nitrogen detector (JF-TSN-6000).

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

[0073]

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

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

[0076] S2——S content in waste tire pyrolysis oil after hydrotreatment.

[0077] Table 1

[0078] Desulfurization rate (%) Denitrification 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 No catalyst 2.2 0.6

[0079] As shown in Table 1, according to Example 1 and Comparative Example 1, the biochar BC carrier loaded with Co-Mo without nitrogen doping and potassium hydroxide activation has a weak interaction between biochar BC and Co and Mo, which makes the active components of Co and Mo easy to leach and aggregate, resulting in low catalytic hydrogenation activity, low desulfurization rate and denitrification rate. Figure 3 It can be seen that the 3Co-10Mo / NBC catalyst of the present invention contains abundant pyridinic nitrogen after nitrogen doping and activation, which can be used as the coordination of metal Mo. Mo anchors pyridinic nitrogen to form N-Mo, promotes the dispersion of Mo, and enhances the interaction between Mo and the nitrogen-doped carbon support, thereby improving the catalytic hydrogenation activity of the catalyst. Figure 5 It can be seen that the color of waste tire pyrolysis oil after 3Co-10Mo / NBC catalytic hydrogenation becomes dark yellow, which is different from the color of waste tire pyrolysis oil ( Figure 1 ), indicating that catalytic hydrogenation has significantly removed the coloring substances in the waste tire pyrolysis oil. From the chromatogram and composition of the hydrogenated oil, catalytic hydrogenation has significantly reduced the sulfides, nitrides and olefins in the oil, and increased the alkanes and cycloalkanes in the oil, which helps to improve the stability and oxidation resistance of the oil and increase the value of the oil.

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

[0081] According to Example 1 and Comparative Example 4, the nitrogen-doped biochar NBC has no hydrogenation activity, and its structure does not directly support the active sites or catalytic mechanism required for the hydrogenation reaction.

[0082] Compared with the one-step calcination of melamine, potassium hydroxide and wheat straw to directly obtain nitrogen-doped biochar, the present invention first prepares biochar by calcination, and then adds melamine and potassium hydroxide to calcine to obtain nitrogen-doped biochar, which can overcome the complexity of wheat straw, melamine and potassium hydroxide cannot interact evenly with wheat straw, so that the nitrogen doping effect in the formed carrier is poor, which leads to the poor activity of the catalyst. Placing the NBC loaded with active ingredients in a tubular furnace and directly calcining with hydrogen will cause the catalyst activity to decrease. On the one hand, impurities such as molybdenum salt precursors in biochar affect the progress of molybdenum carburization reaction, resulting in uneven distribution of generated active metals. On the other hand, the pore structure of biochar changes, further affecting the loading of active metals.

[0083] Effect Example 2

[0084] The material prepared in Example 1 was subjected to waste tire pyrolysis oil hydrogenation and quality improvement, specifically comprising: weighing 0.3 g of catalyst and placing it in a high-pressure reactor, selecting real waste tire pyrolysis oil (components such as Figure 1 2g of 200ml / min was added to the autoclave as the raw material, and then N2 (100mL / min) was introduced to purge for 10min to remove the residual air in the autoclave, and then H2 was introduced and pressurized to 6MPa, with a stirring rate of 300r / min. After that, the autoclave was heated to 330℃ at a heating rate of 10℃ / min, and the temperature was kept for 6h after stabilization. After the reaction was completed, the reactor was taken out and cooled in an ice-water bath. The reactor was repeatedly cleaned with tetrahydrofuran, filtered with a sand core funnel, and the tetrahydrofuran was removed by rotary evaporation to obtain the waste tire pyrolysis oil after hydrogenation. The material composition of the hydrogenation oil was detected by Py-GC / MS, and the sulfur and nitrogen in the hydrotreated oil were analyzed by a sulfur and nitrogen detector (JF-TSN-6000). When the catalyst was circulated, the catalytic material filtered from the sand core funnel was dried and weighed, and added to the autoclave. The subsequent experimental steps were the same as above. The yield of the three-phase product obtained after the catalyst was reused is 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 rate and denitrification rate in at least 7 reuses without any treatment, and the yield of the waste tire pyrolysis oil obtained after hydrogenation treatment is maintained at more than 89.69wt.%, with a high oil yield. Figure 4 It can be seen that after seven cycles, the phase of the Co-Mo / NBC catalyst did not change. Figure 7It can be seen that the second reduction peak of Co-Mo / NBC shows a higher temperature (542℃→521℃) than that of Mo / NBC, indicating that the addition of the additive Co enhances the interaction between the catalyst and the support, which is beneficial to enhance the stability of the catalyst. The second reduction peak of Co-Mo / NBC shows a higher temperature (512℃→496℃) than that of Co-Mo / BC, indicating that nitrogen doping enhances the interaction 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 solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a hydrogenation upgrading catalyst, characterized in that: The steps include: (1) calcining wheat straw to obtain biochar, then adding KOH and nitride to mix evenly and calcining under inert gas, and finally washing and drying to obtain nitrogen-doped biochar; (2) The nitrogen-doped biochar is immersed in a cobalt salt and molybdenum salt solution, stirred, ultrasonicated, and dried, and then calcined under nitrogen. After cooling, the biochar is calcined under hydrogen to obtain a hydrogenation catalyst.

2. The method for preparing the hydrogenation-upgrading catalyst according to claim 1, characterized in that: The mass ratio of the biochar, KOH and nitride is 1:2-3:0.16-0.

17.

3. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that: In the step (1), the temperature of calcining the wheat straw is 700-900°C, the time is 1-3h, and the heating rate is 10-40°C / min.

4. The method for preparing the hydrogenation upgrading catalyst according to claim 1, characterized in that: In the step (1), the calcination temperature under inert gas is 800-900° C., the time is 1-3 hours, the heating rate is 10-40° C. / min, and the flow rate of the inert gas is 30-80 mL / min.

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

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

7. The method for preparing the hydrogenation-upgrading catalyst according to claim 1, characterized in that: In the step (2), the calcination temperature under hydrogen is 500-800° C., the time is 3-6 hours, the heating rate is 10-40° C. / min, and the flow rate of hydrogen is 20-60 mL / min.

8. The method for preparing the hydrogenation upgrading catalyst according to claim 1, characterized in that: 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.

9. The hydro-upgrading catalyst prepared by the method for preparing the hydro-upgrading catalyst according to any one of claims 1 to 8.

10. Use of the hydrogenation upgrading catalyst according to claim 9 in hydrogenation upgrading of waste tire pyrolysis oil.

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