Method for recycling silicon poisoning hydrogenation catalyst

Abstract

The invention provides a recycling method of a silicon poisoning hydrogenation catalyst, which comprises the following steps: cleaning, drying, roasting and crushing the silicon poisoning hydrogenation catalyst, dispersing the silicon poisoning hydrogenation catalyst into a mixed solution of an aluminum salt and an organic ligand, and carrying out hydrothermal treatment, separation, washing and drying; and dipping, adding a solution containing hydrogenation active metal salt, drying, forming, drying and roasting to obtain the hydrofining catalyst. The method can be used for recycling the silicon poisoning hydrogenation catalyst, in the newly prepared catalyst, silicon species on the waste catalyst are utilized, on one hand, anchoring dispersion of Al is facilitated, on the other hand, silicon interacts with Al in Al-MOF growing on the surface of the catalyst, the structural property and the surface property of a composite carrier are changed, and the performance of the catalyst is improved. The interaction of silicon and aluminum during roasting is utilized to generate an acid center, so that the acidity of the catalyst can be properly increased, and the content of B acid is increased.

Description

Technical Field

[0001] This invention relates to a method for reusing silicon-poisoned hydrogenation catalysts, belonging to the field of waste hydrogenation catalyst regeneration technology. Background Technology

[0002] Hydrotreating technology is widely used in the petrochemical industry. Almost every refinery in the world has a hydrotreating unit, resulting in the use of a large amount of hydrotreating catalysts annually, along with the production of a significant amount of spent catalysts. The price of raw materials for hydrotreating catalysts fluctuates frequently, leading to changes in catalyst costs. Considering stringent environmental regulations and economic factors, the reuse of spent catalysts is essential.

[0003] Hydrotreating catalysts often experience deactivation, including carbon buildup and poisoning. Silicon can cause permanent deactivation, rendering many silicon-poisoned catalysts unusable and generating large amounts of waste. This waste leads to environmental pollution and resource waste. CN118371275A discloses a method for regenerating a deactivated catalyst after treatment. The method involves mixing a cleaning agent and the poisoned catalyst, ultrasonically treating the mixture, washing it to neutral, and drying it to obtain a sample. A precious metal solution is then sprayed onto the sample to obtain a regenerated catalyst. This method utilizes a specific type of strong alkali, flocculant, and surfactant to effectively remove toxic silicon species from the poisoned catalyst. It is time-efficient, simple to operate, and achieves a high silicon removal rate. The combination of cleaning and spraying with a precious metal solution ensures the regenerated catalyst's catalytic performance is close to that of a fresh catalyst. This process achieves the regeneration and reuse of silicon-poisoned catalysts. However, this method is costly due to the use of precious metals for active regeneration. Furthermore, the application of strong alkalis and flocculants can lead to the loss of metal components while washing away silicon from the original catalyst, resulting in underutilization of resources. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for reusing silicon-poisoned hydrogenation catalysts. This technology is highly operable, simple in process, and achieves resource utilization of spent catalysts, saving resources, reducing costs, and meeting environmental protection requirements. The catalyst prepared by this method exhibits excellent hydrogenation refining performance.

[0005] The technical solution of the present invention is as follows:

[0006] A method for reusing a silicon-poisoned hydrogenation catalyst includes the following steps:

[0007] (1) First, the silicon-poisoned hydrogenation catalyst is cleaned, dried, calcined, and pulverized;

[0008] (2) Disperse the pulverized solid in (1) into a mixed solution of aluminum salt and organic ligand, perform hydrothermal treatment, and then separate, wash, and dry;

[0009] (3) Before or after molding, the product containing hydrogenated active metal salt is impregnated with a solution, dried and calcined to obtain a hydrogenated refining catalyst.

[0010] Furthermore, the silicon poisoning hydrogenation catalyst mentioned in step (1) is a deactivated silicon scavenger, which is a catalyst with alumina as a support and no active metal component, or whose active component is at least one of Group VIB metals and Group VIII metals.

[0011] Furthermore, the cleaning in step (1) is carried out using an organic solvent, which is selected from at least one of methanol, ethanol, isopropanol, n-butanol, isobutanol, tetrahydrofuran, ethyl acetate, butyl acetate, acetone, diethyl ether, petroleum ether, n-hexane and cyclohexane, preferably at least one of petroleum ether, ethanol and isopropanol.

[0012] Furthermore, the cleaning in step (1) is performed at least four times; the volume ratio of the organic solvent to the weight ratio of the catalyst is 2-50; preferably 10-35.

[0013] Furthermore, the drying temperature in step (1) is 80-200℃, preferably 100-180℃.

[0014] Furthermore, the roasting temperature in step (1) is 350-750℃, preferably 500-700℃. The roasting time is 1-10h, preferably 2-6h.

[0015] Furthermore, the pulverization in step (1) involves pulverizing the catalyst to 100-300 mesh, preferably 200-220 mesh.

[0016] Furthermore, the active component is at least one of the VIB metals and at least one of the VIII metals.

[0017] Furthermore, the VIB metal is at least one of W and Mo; the VIII metal is at least one of Ni and Co.

[0018] Furthermore, the amount of hydrogenation active metal salt added is such that, based on the total mass of the catalyst, the proportion of the Group VIB metal oxide is 6-25%, preferably 8-18%, and the proportion of the Group VIII metal oxide is 0.5-8%, preferably 2-6%.

[0019] Furthermore, the aluminum salt mentioned in step (2) is selected from at least one of aluminum nitrate, aluminum chloride, aluminum sulfate and aluminum isopropoxide, preferably at least one of aluminum nitrate and aluminum sulfate.

[0020] Furthermore, the amount of aluminum salt added is based on a molar ratio of aluminum to silicon in the catalyst of 3-62:1, preferably 6-38:1.

[0021] Furthermore, the organic ligand mentioned in step (2) is selected from at least one of terephthalic acid, pyromellitic acid and 2-amino-terephthalic acid, preferably at least one of terephthalic acid and pyromellitic acid.

[0022] Furthermore, the solvent of the mixed solution in step (2) is selected from at least one of deionized water, methanol and N,N-dimethylformamide.

[0023] Furthermore, the molar ratio of the organic ligand to aluminum in step (2) is 0.5-5:1; preferably 1-2.5:1.

[0024] Furthermore, the temperature of the hydrothermal treatment in step (2) is 100-240℃, preferably 160-200℃; and the time is 6-24h.

[0025] Furthermore, the drying temperature in step (2) is 80-180℃, preferably 100-150℃. The drying method is ordinary drying or vacuum drying, preferably vacuum drying.

[0026] Furthermore, the drying temperature after impregnation of the metal in step (3) is 60-150℃, preferably 80-120℃; the drying time is 5-10h, preferably 6-8h.

[0027] Furthermore, the drying temperature in step (3) is 80-150°C, preferably 100-130°C;

[0028] Furthermore, the roasting temperature in step (3) is 300-700℃, preferably 350-650℃; the roasting time is 3-8h, preferably 3-5h.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] (1) The method of the present invention can be used for the recycling of silicon poisoning hydrogenation catalysts. In the newly prepared catalyst, the silicon species on the waste catalyst can be used to help anchor and disperse Al. On the other hand, the interaction between silicon and Al in Al-MOF grown on the catalyst surface changes the structural and surface properties of the composite support. The interaction between silicon and aluminum during calcination generates acid centers, which can appropriately increase the acidity of the catalyst and increase the Brønsted acid content.

[0031] (2) The hydrothermal treatment method can improve the pore properties of the catalyst on the one hand, and by adding organic ligands and aluminum salts, MOF materials with high specific surface area can be grown in situ on the catalyst, which helps the subsequent dispersion of active metals and prevents the high-temperature agglomeration and sintering of the active phase.

[0032] (3) By further impregnating the active metal, the support is a composite support based on Al-MOF, alumina and silica. The active components are evenly dispersed, and the MOF material on the catalyst is sacrificed as a soft template during the subsequent calcination process. This can adjust the pore size of the catalyst, which is conducive to the adsorption and diffusion of large reactant molecules on the catalyst. This results in a catalyst with excellent performance. At the same time, it also realizes the resource utilization of waste catalyst, saves costs, and meets environmental protection requirements. Detailed Implementation Plan

[0033] The present invention will be described in detail below through embodiments, but the present invention is not limited to these embodiments.

[0034] Example 1

[0035] (1) First, take 20g of deactivated metal-free silicon scavenger and wash it with ethanol to remove oil. The washing is repeated 6 times, with 300mL of ethanol used each time. Then, dry it at 150℃ for 4h and calcine it at 550℃ for 3h. After that, pulverize it to 200-220 mesh.

[0036] (2) Dissolve 24.5g of aluminum nitrate nonahydrate in 300mL of N,N-dimethylformamide. After it is fully dissolved, add 21.7g of terephthalic acid and stir to dissolve to obtain a mixture. Take 10g of the powder obtained in step (1) (the SiO2 content is measured to be 21.7%) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 200℃ for 12h. Separate the solid by filtration, wash 4 times with anhydrous ethanol, and dry at 150℃ for 5h.

[0037] (3) Dissolve 5.3g of nickel nitrate and 5.4g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 110°C for 4 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 0.6g, and add 25.4g of water to obtain a clover-type catalyst precursor. Dry the precursor at 110°C for 3 hours and then calcine it at 550°C for 3 hours to obtain hydrogenation refining catalyst A.

[0038] Example 2

[0039] (1) First, take 20g of deactivated metal-free silicon scavenger and wash it with ethanol to remove oil. The washing is repeated 6 times, with 300mL of ethanol used each time. Dry it at 130℃ for 6h, calcine it at 500℃ for 5h, and then pulverize it to 200-220 mesh.

[0040] (2) Dissolve 11.5g of aluminum nitrate nonahydrate in 150mL of N,N-dimethylformamide. After it is fully dissolved, add 7.6g of terephthalic acid and stir thoroughly to dissolve to obtain a mixture. Take 10g of the powder obtained in step (1) (the SiO2 content was measured to be 21.7%) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 180℃ for 12h. Separate the solid by filtration, wash 4 times with anhydrous ethanol, and dry at 150℃ for 5h.

[0041] (3) Dissolve 3.6g of nickel nitrate and 3.2g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 110°C for 4 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 0.4g, and add 17.3g of water to obtain a clover-type catalyst precursor. Calcine the precursor at 550°C for 3 hours to obtain hydrogenation refining catalyst B.

[0042] Example 3

[0043] (1) First, take 20g of deactivated metal-free silicon scavenger and wash it with ethanol to remove oil. The washing is repeated 6 times, and the amount of ethanol used each time is 250mL. Then, dry it at 130℃ for 6h, calcine it at 600℃ for 3h, and then pulverize it to 200-220 mesh.

[0044] (2) Dissolve 79.9g of aluminum nitrate nonahydrate in 1000mL of N,N-dimethylformamide. After it is fully dissolved, add 88.5g of terephthalic acid and stir to dissolve to obtain a mixture. Take 10g of the powder obtained in step (1) (the SiO2 content in the deactivator is 21.7%) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 200℃ for 10h. Separate the solid by filtration, wash with anhydrous ethanol 4 times, and dry at 150℃ for 5h.

[0045] (3) Dissolve 6.2g of nickel nitrate and 17.5g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 120°C for 4 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 1.4g, and add 59.9g of water to obtain a clover-type catalyst precursor. Calcine the precursor at 600°C for 2 hours to obtain hydrogenation refining catalyst C.

[0046] Example 4

[0047] (1) First, take 20g of deactivated metal-free silicon scavenger and wash it with ethanol to remove oil. The washing is done 5 times, and the amount of ethanol used each time is 200mL. Then dry it at 110℃ for 6h, calcine it at 650℃ for 2h, and then pulverize it to 200-220 mesh.

[0048] (2) Dissolve 126.9g of aluminum nitrate nonahydrate in 1600mL of N,N-dimethylformamide. After it is fully dissolved, add 168.6g of terephthalic acid and stir to dissolve to obtain a mixture. Take 10g of the powder obtained in step (1) (the SiO2 content in the deactivator is 21.7%) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 200℃ for 12h. Separate the solid by filtration, wash with anhydrous ethanol 4 times, and dry at 150℃ for 5h.

[0049] (3) Dissolve 1.91g of nickel nitrate and 1.92g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 110°C for 6 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 2.1g, and add 89.4g of water to obtain a clover-type catalyst precursor. Calcine the precursor at 640°C for 2 hours to obtain hydrogenation refining catalyst D.

[0050] Comparative Example 1

[0051] (1) First, take 100g of deactivated metal-free silicon scavenger and wash it with ethanol to remove oil. The washing is repeated 6 times, with 2000mL of ethanol used each time. Dry it at 110℃ for 6h, calcine it at 650℃ for 2h, and then pulverize it to 200-220 mesh.

[0052] (2) Take 60g of the powder obtained in step (1) (the SiO2 content is 21.7%), mix it with 129.1g of aluminum nitrate nonahydrate, dry at 110℃ for 3h, and calcine at 650℃ for 3h.

[0053] (3) Dissolve 14.8g of nickel nitrate and 14.9g of ammonium heptamolybdate, and impregnate them onto the powder from step (1) using an equal volume impregnation method. Dry the powder at 110°C for 6 hours, and then extrude the dried sample into strips. The extrusion aid is guar gum powder, with an addition amount of 3.5g and a water addition amount of 152g. This yields a clover-type catalyst precursor, which is dried at 110°C for 3 hours and calcined at 640°C for 2 hours to obtain the hydrogenation refining catalyst E.

[0054] Comparative Example 2

[0055] (1) First, take 20g of deactivated metal-free silicon-collecting agent and crush it to 200-220 mesh.

[0056] (2) Dissolve 24.5g of aluminum nitrate nonahydrate in 300mL of N,N-dimethylformamide. After it is fully dissolved, add 21.7g of terephthalic acid and stir until it is completely dissolved. Take 11g of the powder in (1) (the SiO2 content was measured to be 21.7% and the carbon deposition was measured to be 9.1%) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 200℃ for 12h. Separate the solid by filtration, wash 4 times with anhydrous ethanol, and dry at 150℃ for 5h.

[0057] (3) Dissolve 5.3g of nickel nitrate and 5.4g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 110°C for 4 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 0.6g, and add 25.4g of water to obtain a clover-type catalyst precursor. Dry the precursor at 110°C for 3 hours and calcine it at 550°C for 3 hours to obtain the hydrogenation refining catalyst F.

[0058] Comparative Example 3

[0059] First, take 20g of deactivated metal-free silicon scavenger (the actual silicon content is 21.7%), and clean it with ethanol to remove oil. The washing is repeated 6 times, with 300mL of ethanol used each time. Dry it at 110℃ for 6h and calcine it at 650℃ for 2h to obtain catalyst G.

[0060] Comparative Example 4

[0061] First, 20g of deactivated metal-free silicon scavenger (measured silicon content 21.7%) was washed with ethanol to remove oil, 6 times, with 300mL of ethanol used each time. The sample was dried at 110℃ for 6h and calcined at 650℃ for 2h. 10g of the calcined sample was used as a support, and 2.5g of nickel nitrate and 2.5g of ammonium heptamolybdate were dissolved and impregnated onto the solid using an equal-volume impregnation method. The sample was dried at 110℃ for 4h and calcined at 650℃ for 2h to obtain catalyst H.

[0062] Comparative Example 5

[0063] (1) Take 20g of fresh silicon scavenger of the same type as the silicon poisoning silicon scavenger used in Example 1 and crush it to 200-220 mesh.

[0064] (2) Dissolve 24.5g of aluminum nitrate nonahydrate in 300mL of N,N-dimethylformamide. After it is fully dissolved, add 21.7g of terephthalic acid and stir until it is completely dissolved. Take 10g of the powder in (1) and add it to the mixture. Stir for 30min and then transfer it to the reaction vessel. Place the reaction vessel in an oven for solvent heat treatment at 200℃ for 12h. Separate the solid by filtration, wash 4 times with anhydrous ethanol, and dry at 150℃ for 5h.

[0065] (3) Dissolve 5.3g of nickel nitrate and 5.4g of ammonium heptamolybdate, and impregnate them onto the solid in step (2) using the equal volume impregnation method. Dry the solid at 110°C for 4 hours. Extrude the dried solid into strips. Use guar gum powder as the extrusion aid, add 0.6g, and add 25.4g of water to obtain a clover-type catalyst precursor. Dry the precursor at 110°C for 3 hours and then calcine it at 550°C for 3 hours to obtain the hydrorefining catalyst J.

[0066] The properties of the catalysts are shown in Table 1.

[0067] Table 1.

[0068]

[0069] Example 5

[0070] This embodiment illustrates the performance of the catalyst for hydrorefining provided by the present invention.

[0071] The catalyst was loaded into a laboratory fixed-bed reactor for reaction, with straight-run diesel as the feedstock, and in-reactor sulfidation was used to sulfide the catalyst.

[0072] Catalyst sulfidation conditions: 2 wt% CS2 jet fuel as sulfiding oil, volume hourly space velocity 1.0 h⁻¹ -1 The catalyst was sulfided at a hydrogen-to-oil volume ratio of 400 and a pressure of 6.0 MPa. The sulfidation temperature was 340℃ and the sulfidation time was 8 hours.

[0073] Reaction conditions: operating pressure 6.5 MPa, reaction temperature 365 °C, hydrogen-to-oil volume ratio 500, and volume hourly space velocity 1.5 h⁻¹. -1 The evaluation results of the properties of raw materials and products are shown in Table 2.

[0074] Table 2.

[0075]

Claims

1. A method for reusing a silicon-poisoned hydrogenation catalyst, comprising the following steps: (1) First, the silicon-poisoned hydrogenation catalyst is cleaned, dried, calcined, and pulverized; (2) Disperse the pulverized solid in (1) into a mixed solution of aluminum salt and organic ligand, perform hydrothermal treatment, and then separate, wash, and dry; (3) Before or after molding, the product containing hydrogenated active metal salt is impregnated with a solution, dried and calcined to obtain a hydrogenated refining catalyst.

2. The method according to claim 1, characterized in that, The silicon poisoning hydrogenation catalyst mentioned in step (1) is a deactivated silicon scavenger. The silicon scavenger is a catalyst with alumina as a support and no active metal component, or with an active component of at least one of Group VIB metals and Group VIII metals.

3. The method according to claim 1, characterized in that, The cleaning in step (1) is carried out using an organic solvent, which is selected from at least one of methanol, ethanol, isopropanol, n-butanol, isobutanol, tetrahydrofuran, ethyl acetate, butyl acetate, acetone, diethyl ether, petroleum ether, n-hexane, and cyclohexane.

4. The method according to claim 1, characterized in that, The roasting temperature in step (1) is 350-750℃ and the roasting time is 1-10h.

5. The method according to claim 1, characterized in that, The pulverization in step (1) involves pulverizing the catalyst to 100-300 mesh.

6. The method according to claim 1, characterized in that, The active component is at least one of the VIB metals and at least one of the VIII metals.

7. The method according to claim 6, characterized in that, The VIB metal is at least one of W and Mo; the VIII metal is at least one of Ni and Co.

8. The method according to claim 1, characterized in that, Based on the total mass of the catalyst, the proportion of Group VIB metal oxides is 6-25%, and the proportion of Group VIII metal oxides is 0.5-8%.

9. The method according to claim 1, characterized in that, The aluminum salt mentioned in step (2) is selected from at least one of aluminum nitrate, aluminum chloride, aluminum sulfate and aluminum isopropoxide.

10. The method according to claim 1, characterized in that, The amount of aluminum salt added is based on a molar ratio of aluminum to silicon in the catalyst of 3-62:

1.

11. The method according to claim 1, characterized in that, The organic ligand mentioned in step (2) is selected from at least one of terephthalic acid, pyromellitic acid and 2-amino-terephthalic acid.

12. The method according to claim 1, characterized in that, The solvent for the mixed solution in step (2) is selected from at least one of deionized water, methanol and N,N-dimethylformamide.

13. The method according to claim 1, characterized in that, The molar ratio of the organic ligand to aluminum is 0.5-5:

1.

14. The method according to claim 1, characterized in that, The temperature of the hydrothermal treatment in step (2) is 100-240℃; the time is 6-24h.

15. The method according to claim 1, characterized in that, The roasting temperature in step (3) is 300-700℃ and the roasting time is 3-8h.

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