A hydroprocessing catalyst, its preparation method and use

Abstract

The application discloses a preparation method of a hydroprocessing catalyst, and the preparation method is as follows: (1) purchasing or preparing an alumina carrier; (2) adopting a solution containing polyfluoroalkoxysilane to perform impregnation treatment on the alumina carrier in step (1), wherein the polyfluoroalkoxysilane is an integer greater than or equal to 7, preferably an integer between 8 and 17; (3) after the impregnation treatment in step (2), the alumina carrier is dried to obtain a modified alumina carrier; (4) introducing an active metal component into the modified alumina in step (3), and after drying, a final hydroprocessing catalyst is obtained. The preparation method of the hydroprocessing catalyst utilizes different molecular weights and boiling points of the polyfluoroalkoxysilane to perform directional acid modification on large channels of the alumina carrier, so as to improve effective acidity of the alumina carrier, and further improve desulfurization and denitrification activity and aromatic hydrocarbon saturation activity of the prepared hydroprocessing catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of hydroprocessing catalyst and its preparation method and application, specifically relates to a kind of high desulfurization denitrogenation, high aromatic saturation hydroprocessing catalyst and its preparation method and application. BACKGROUND

[0002] The acidity of hydrogenation catalyst carrier is important to improve the activity of hydrogenation catalyst. However, the acidity distributed on the surface of the small pores of the carrier will increase the difficulty of the diffusion of the intermediate products in the reaction, leading to problems such as coking and carbon deposition, affecting the activity and service life of the hydrogenation catalyst, and thus playing a negative role on the performance of the catalyst. Therefore, it is necessary to direct control the acid additive in the macropore when the hydrogenation catalyst is acid modified, especially when it is strongly acid modified.

[0003] CN106669866A discloses a method for adjusting the acidity of a catalyst, which uses a solution containing ammonium fluoroborate and 2-amino-1,3-propanediol to impregnate and treat the deactivated hydrogenation catalyst after carbon burning. This method adjusts the acidity while changing the dispersion of active metals on the surface of the carrier, improving the hydrogenation effect of the regenerated catalyst. However, ammonium fluoroborate can carry active metal ions into the small pore channels of the catalyst during the treatment process, leading to the loss of active metals and the reduction of the service life of the catalyst.

[0004] CN1872959A discloses a fluorine-containing hydrogenation catalyst with alumina as the carrier and its preparation method. The carrier is prepared by mixing alumina with soluble fluorine-containing compounds such as ammonium fluoride, ammonium fluoroborate, hydrofluoric acid, hydrofluoride, fluorosilicic acid, and fluorosilicate. The catalyst with introduced fluorine has strong denitrification ability. However, the indiscriminate introduction of fluorine into the alumina bulk phase can cause the pore channels of the catalyst to become smaller, and the aggregation of fluorine in the small pores can increase the coking and carbon deposition of the catalyst during use.

[0005] CN1853779A discloses a fluorine-containing hydrogenation catalyst with silica-alumina as the carrier and its preparation. Fluorine is introduced by separately or simultaneously impregnating the silica-alumina carrier with a solution containing fluorine, molybdenum, nickel, and tungsten compounds. The fluorine-containing compounds are one or more of hydrofluoric acid, hydrofluoride, fluorosilicic acid, fluorosilicate, and ammonium fluoride. The catalyst provided by the invention has high activity and better hydrofining performance. The introduction of small molecule fluorides in the impregnation solution causes differences in the diffusion and adsorption properties of fluorides on the surface of the active metal carrier, leading to poor matching between the metal and the acidity, and the catalyst is prone to coking and carbon deposition during use, especially during the processing of heavy oil products. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a hydroprocessing catalyst, a preparation method and application thereof. The preparation method of the hydroprocessing catalyst utilizes multi-fluoroalkoxy silane with different molecular mass and boiling point to perform directional acid modification on the large pores of the alumina carrier, so as to improve the effective acidity of the alumina carrier, and further improve the desulfurization and denitrification and aromatic hydrocarbon saturation activity of the prepared hydroprocessing catalyst.

[0007] The first aspect of the present application is to provide a preparation method of a hydroprocessing catalyst, which is as follows:

[0008] (1) purchasing or preparing an alumina carrier;

[0009] (2) performing impregnation treatment on the alumina carrier in step (1) by using a solution containing multi-fluoroalkoxy silane, wherein the number of fluorine atoms in the multi-fluoroalkoxy silane is an integer of 7 or more, and preferably an integer between 8 and 17;

[0010] (3) obtaining a modified alumina carrier after drying the alumina carrier after the impregnation treatment in step (2);

[0011] (4) introducing an active metal component into the modified alumina in step (3), and obtaining a final hydroprocessing catalyst after drying.

[0012] In step (1) of the method of the present application, the alumina carrier can be purchased as a commercial product or prepared according to the prior art. The preparation method is as follows: mixing aluminum hydroxide dry gel powder and deionized water in a certain proportion, while adding an additive, performing kneading, rolling, and then performing extrusion treatment, drying, and calcination to obtain the alumina carrier. In step (1), the mass ratio of the aluminum hydroxide dry gel powder to water is 0.7:1-1.5:1, and preferably 0.9:1-1.2:1. The additive is one or more of nitric acid, citric acid, and acetic acid, and the amount is 0.5%-3.0% of the mass of the dry gel powder, and preferably 1.0%-2.0%. The kneading time is 0.2-2.0 hours, and preferably 0.5-1.0 hours. The rolling time is 0.2-2.0 hours, and preferably 0.5-1.0 hours. The extrusion pressure is 2.0-40.0 MPa, and preferably 15.0-25.0 MPa. The drying temperature is 100-180℃, and preferably 120-160℃, and the time is 1.0-8.0 hours, and preferably 2.0-6.0 hours. The calcination temperature is 400-800℃, and preferably 500-750℃, and the time is 3.0-10.0 hours, and preferably 4.0-8.0 hours.

[0013] In step (1) of the method of the present application, the properties of the alumina carrier are as follows: the specific surface area is 250-370m 2 / g, and preferably 280-340m 2 / g, the pore volume of the support is 0.6-1.0 cm 3 / g, preferably 0.7-0.9 cm 3 / g.

[0014] In step (2) of the method, the polyfluoroalkoxysilane has a carbon chain of not less than 6 carbon atoms and a boiling point of higher than 200℃ at normal pressure.

[0015] In step (2) of the method, the polyfluoroalkoxysilane is one or more of tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, 1H,1H,2H,2H-perfluorooctylsilane, nonafluorohexyltriethoxysilane, (3,3,3-trifluoropropyl)methyldimethoxysilane, tetrakis(trifluoroacetoxyl)silane, and 3-trifluoroacetoxylpropyltrimethoxysilane.

[0016] In step (2) of the method, the solvent used in the solution containing the polyfluoroalkoxysilane is one or more of alcohols, small molecule aromatic hydrocarbons, and cycloalkanes. The alcohols are one or more of ethanol, ethylene glycol, and 1,3-propanediol, the small molecule aromatic hydrocarbons are one or more of benzene, toluene, xylene, and ethylbenzene, and the cycloalkanes are one or more of cyclohexane, n-heptane, n-hexane, and decalin.

[0017] In step (2) of the method, the mass fraction of the polyfluoroalkoxysilane in the solution is 1.0%-15%, preferably 2.0%-10.0%.

[0018] In step (2) of the method, the impregnation treatment can be performed by using the prior art, such as equal-volume impregnation or over-volume impregnation.

[0019] In step (2) of the method, the solution containing the polyfluoroalkoxysilane is allowed to stand for 12-24 hours after impregnating the alumina support.

[0020] In step (3) of the method, the solvent can be recovered and reused by using the prior art, such as by rotary evaporation or in a vacuum drying process after the impregnation treatment is completed.

[0021] In step (3) of the method, the drying temperature is 100-180℃, and the drying time is 2.0-8.0 hours, preferably, the drying temperature is 120-160℃, and the drying time is 3.0-6.0 hours. Preferably, the drying is performed under vacuum, and the vacuum degree is controlled to be 0.2-5.0 tor, preferably 0.5-2.0 tor.

[0022] In step (4) of the method, the active metal component is a metal of Group VIB and / or Group VIII, the metal of Group VIB is preferably molybdenum and / or tungsten, and the metal of Group VIII is preferably cobalt and / or nickel.

[0023] In step (4) of the method, the active metal component is introduced into the modified alumina of step (3) by impregnation, and the impregnation can be carried out by equal volume impregnation or volume impregnation.

[0024] In step (4) of the method, the drying temperature is 100-160 DEG C, and the drying time is 1.0-8.0 hours.

[0025] The second aspect of the application provides a hydroprocessing catalyst prepared by the above method, the mass content of the metal element of Group VIB in the hydroprocessing catalyst is 14%-30% as calculated based on the oxide, preferably 18%-25%, the mass content of the metal element of Group VIII is 2%-7% as calculated based on the oxide, preferably 3%-6%,

[0026] The mass content of fluorine is 0.2%-3% as calculated based on the element, preferably 0.5%-2%, and the rest is the carrier.

[0027] In the catalyst, the metal element of Group VIB is preferably molybdenum, and the mass content of MoO3 is 14%-30%, preferably 18%-25%; the metal element of Group VIII is preferably nickel, and the mass content of NiO is 2%-7%, preferably 3%-6%.

[0028] The application of the above hydroprocessing catalyst is under the following operating conditions: the reaction temperature is 250-450 DEG C, the reaction pressure is 3.0-25.0 MPa, and the liquid hourly space velocity is 0.2-2.5 h -1 .

[0029] In the application of the catalyst prepared by the method, the properties of the raw oil are as follows: the 95% distillation point of the oil product is 450-700 DEG C, preferably 500 DEG C-650 DEG C, the nitrogen content in the oil product is 200-3000 ug / g, the sulfur content is 1.0-4.0 wt%, and the aromatic hydrocarbon content is 30-70 wt%.

[0030] The inventors have found through in-depth research that the multi-fluoroalkoxy silane is difficult to enter the small pores of alumina due to its high polarity, and the application utilizes the characteristic that the multi-fluoroalkoxy silane is difficult to enter the small pores of alumina due to its high polarity, adsorbs the multi-fluoroalkoxy silane in the positions with larger pores in the carrier, and thus realizes the purpose of directional loading of fluorine for acid modification.

[0031] The application also provides a hydroprocessing catalyst, a preparation method and application thereof.

[0032] (1) The distribution of fluorine atoms providing acidity is matched with the pore properties of the catalyst, so that the catalyst can ensure the overall acidity while avoiding the problem of rapid carbon deposition in small pores during use.

[0033] (2) The concentrated distribution of fluorine atoms in the micro area makes the fluorine modification effect more concentrated, improves the matching of active phases and fluorine elements, further improves the utilization rate of fluorine, and improves the hydrogenation effect of the catalyst. DETAILED DESCRIPTION

[0034] The effects and advantages of the present application will be further illustrated by the following examples and comparative examples, but the following examples do not limit the method of the present application, and in the context of the present application, including the examples and comparative examples, the mass percentage is used unless otherwise specified.

[0035] In the examples and comparative examples of the present application, ammonia-TPD is used to characterize the acidity, and strong acid refers to strong acid with acid strength > 400℃, and the specific determination method is as follows: under high-purity helium atmosphere, heat to 450℃, and keep constant for 1.0 hour, then cool to 60℃. Switch 5% NH3-He gas through the sample, adsorb ammonia at 80℃ for 1.0 hour, and heat to 100℃ under helium atmosphere for 0.5 hour. When the baseline is stable, the desorption experiment can be started, and hydrochloric acid is used to titrate the desorbed ammonia, the temperature rising rate during the desorption process is 10℃ / min, and the temperature is raised to 900℃ and maintained for 0.5 hour.

[0036] In the examples and comparative examples of the present application, the preparation method of alumina is as follows: take 1000.0 g of alumina dry gel powder, add 30.0 g of citric acid, 20.0 g of sesbania powder, and 50.0 g of ammonium bicarbonate, mix uniformly, then add 900.0 g of water solution containing 3.0% nitric acid, roll for 30.0 min, and then extrude into strips with a three-leaf clover hole plate with a diameter of 2.0 mm. After drying at 120℃ for 4.0 h and calcining at 700℃ for 6.0 h, the obtained carrier is recorded as S-0.

[0037] Example 1:

[0038] Take 6.0 g of tridecafluorooctyltriethoxysilane and 150 g of cyclohexane to prepare an impregnation solution FQ-1.

[0039] Take 200.0 g of S-0, impregnate FQ-1 on S-0, and stand for 20.0 hours. Then control the vacuum degree at 1.0 torr, dry at 120℃ for 4.0 hours, recover the solvent, and obtain the fluorine-containing silane carrier, which is recorded as FS-1.

[0040] Take 60.0 g of ammonium molybdate, 35.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water to prepare a solution, which is recorded as MQ-1.

[0041] FS-1 was impregnated with MQ-1 and dried at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is designated Cat-1.

[0042] Example 2:

[0043] An impregnation solution FQ-2 was prepared by taking 10.0 g of nonafluorohexyltriethoxysilane and 150 g of cyclohexane.

[0044] FS-2 was prepared by impregnating S-0 with FQ-2 and allowing it to stand for 20.0 hours. It was then dried at 120°C for 4.0 hours under a vacuum of 1.0 torr and the solvent was recovered. The resulting fluorosilane-containing support is designated FS-2.

[0045] A solution was prepared by taking 70.0 g of ammonium molybdate, 40.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water. The solution is designated MQ-2.

[0046] FS-2 was impregnated with MQ-3 and dried at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is designated Cat-2.

[0047] Example 3:

[0048] An impregnation solution FQ-3 was prepared by taking 8.0 g of heptadecafluorodecyltrimethoxysilane and 150 g of cyclohexane.

[0049] FS-3 was prepared by impregnating S-0 with FQ-3 and allowing it to stand for 20.0 hours. It was then dried at 120°C for 4.0 hours under a vacuum of 1.0 torr and the solvent was recovered. The resulting fluorosilane-containing support is designated FS-3.

[0050] A solution was prepared by taking 80.0 g of ammonium molybdate, 45.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water. The solution is designated MQ-3.

[0051] FS-3 was impregnated with MQ-3 and dried at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is designated Cat-3.

[0052] Example 4:

[0053] An impregnation solution FQ-4 was prepared by taking 11.0 g of tetrakis(trifluoroacetoxy)silane and 150 g of cyclohexane.

[0054] Take 200.0 g of S-0 and impregnate with FQ-4. Let stand for 20.0 hours. Dry at 120°C for 4.0 hours under a controlled vacuum of 1.0 torr. Recover the solvent and the resulting fluorosilane- containing support is labeled FS-4.

[0055] Take 90.0 g of ammonium molybdate, 50.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water and make a solution labeled MQ-4.

[0056] Impregnate FS-4 with MQ-4 and dry at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is labeled Cat-4.

[0057] Comparative Example 1 (Blank)

[0058] Take 70.0 g of ammonium molybdate, 40.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water and make a solution labeled DQ-1.

[0059] Impregnate 200.0 g of S-0 with DQ-1 and dry at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is labeled DCT-1.

[0060] Comparative Example 2 (Simple Fluorine)

[0061] Make a fluorine-containing solution DFQ-2 by dissolving 8.0 g of NH4F in 150 g of deionized water.

[0062] Impregnate 200.0 g of S-0 with DFQ-1 and then dry at 120°C for 4.0 hours and calcine at 420°C for 4.0 hours. The resulting support is labeled DS-2.

[0063] Take 70.0 g of ammonium molybdate, 40.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water and make a solution labeled DS-2.

[0064] Impregnate 200.0 g of S-0 with DQ-2 and dry at 120°C for 4.0 hours and then at 150°C for 2.0 hours. The resulting catalyst is labeled DCT-2.

[0065] Comparative Example 3 (Small Molecule Fluorosilane)

[0066] Make an impregnation solution DFQ-3 by dissolving 10.0 g of (trifluoromethyl)trimethylsilane in 150 g of cyclohexane.

[0067] Take 200.0 g S-0, DFQ-3 is impregnated on S-0, and is left for 20.0 hours. After controlling the vacuum degree at 1.0 torr, it is dried at 120°C for 4.0 hours, and the recovered solvent is taken as DS-3.

[0068] Take 70.0 g of ammonium molybdate, 40.0 g of nickel nitrate hexahydrate, and 180 ml of deionized water, and configure them into a solution, which is taken as DMQ-3.

[0069] Impregnate DFS-3 with DMQ-3, dry it at 120°C for 4.0 hours, and then dry it at 150°C for 2.0 hours, and the obtained catalyst is taken as DCT-3.

[0070] The above catalyst is subjected to property analysis, and the obtained results are shown in Table 1.

[0071] Table 1 Catalyst properties

[0072]

[0073] The above catalyst is subjected to sulfidation, and the sulfidation procedure is as follows: catalyst sulfidation, a DMDS 4.0% cyclohexane solution is configured, and the flow rate of the sulfidation liquid is 2.0 mL / h•g-1oxidized catalyst. The hydrogen pressure during sulfidation is 4.0 MPa, and the hydrogen flow rate is 15.0 ml / min·g -1 The catalyst. The sulfidation is divided into two temperature stages, the first stage temperature is 230°C, and the sulfidation time is 4.0 hours, and the second stage sulfidation temperature is 320°C, and the sulfidation time is 4.0 hours.

[0074] After the sulfidation is completed, a hydrogenation experiment evaluation is performed, and the properties of the evaluation raw oil are shown in Table 2.

[0075] Table 2 Properties of the evaluation raw oil

[0076]

[0077] The oil product is evaluated. The evaluation conditions are as follows: the reaction temperature is 370°C, the reaction hydrogen pressure is 15.0 MPa, the liquid hourly space velocity is 0.1 h -1 , and the hydrogen / oil ratio is 1000:1. The oil product after 600 hours of evaluation is taken for analysis, and the obtained results are shown in Table 3.

[0078] Table 3 Oil product evaluation results

[0079]

[0080] As can be seen from the evaluation results, using a macromolecular fluorosilane as an alumina acid modifier can effectively improve the desulfurization, denitrification, and de- aromatic capacity of the hydrogenation catalyst.

Claims

1. A method for preparing a hydrogenation catalyst, characterized in that: The preparation method of the hydrogenation catalyst is as follows: (1) Procurement or preparation of alumina carriers; (2) The alumina support in step (1) is impregnated with a solution containing polyfluoroalkoxysilane, wherein the polyfluoroalkoxysilane is an integer with 7 or more fluorine atoms in the polyfluoroalkoxysilane; (3) The alumina carrier after impregnation treatment in step (2) is dried to obtain the modified alumina carrier; (4) Introduce active metal components into the modified alumina in step (3), and obtain the final hydrogenation catalyst after drying.

2. The method according to claim 1, characterized in that: The polyfluoroalkoxysilane is a fluoroalkoxysilane in which the number of fluorine atoms is an integer between 8 and 17.

3. The method according to claim 1, characterized in that: In step (1), the alumina support has the following properties: specific surface area of ​​250-370 m². 2 / g, the pore volume of the carrier is 0.6-1.0 cm³. 3 / g.

4. The method according to claim 1, characterized in that: In step (1), the alumina support has the following properties: specific surface area of ​​280-340 m². 2 / g, the pore volume of the carrier is 0.7-0.9cm³. 3 / g.

5. The method according to claim 1, characterized in that: In step (2), the polyfluoroalkoxysilane has a carbon chain of no less than 6 carbon atoms and a boiling point above 200°C under normal pressure.

6. The method according to claim 1, characterized in that: In step (2), the polyfluoroalkoxysilane is one or more of the following: tridecylfluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, 1H,1H,2H,2H-perfluorooctylsilane, nonafluorohexyltriethoxysilane, and tetra(trifluoroacetoxy)silane.

7. The method according to claim 1, characterized in that: In step (2), the solvent used for the solution containing polyfluoroalkoxysilane is one or more of alcohols, small molecule aromatics and cycloalkanes.

8. The method according to claim 7, characterized in that: The alcohol is one or more of ethanol, ethylene glycol, and 1,3-propanediol; the small molecule aromatic hydrocarbon is one or more of benzene, toluene, xylene, and ethylbenzene; and the cycloalkanes are one or more of cyclohexane and decahydronaphthalene.

9. The method according to claim 1, characterized in that: In step (2), the solvent used for the solution containing polyfluoroalkoxysilane is one or more of n-heptane and n-hexane.

10. The method according to claim 1, characterized in that: In step (2), the mass fraction of polyfluoroalkoxysilane in the solution is 0.1%-5%.

11. The method according to claim 10, characterized in that: In step (2), the mass fraction of polyfluoroalkoxysilane in the solution is 0.2%-3.0%.

12. The method according to claim 1, characterized in that: In step (2), the alumina carrier in step (1) is impregnated with a solution containing polyfluoroalkoxysilane and left to stand for 12-24 hours.

13. The method according to claim 1, characterized in that: In step (3), after the impregnation treatment is completed, the solvent is recovered and reused.

14. The method according to claim 1, characterized in that: In step (3), the drying temperature is 100-180℃ and the drying time is 2.0-8.0 hours.

15. The method according to claim 14, characterized in that: In step (3), the drying temperature is 120-160℃ and the drying time is 3.0-6.0 hours.

16. The method according to claim 14, characterized in that: In step (3), the drying is vacuum drying, and the vacuum degree is controlled at 0.2-5.0 tor during the drying process.

17. The method according to claim 16, characterized in that: In step (3), the vacuum degree is controlled at 0.5-2.0 tor during the drying process.

18. The method according to claim 1, characterized in that: In step (4), the active metal component is a metal of Group VIB and / or Group VIII.

19. The method according to claim 1, characterized in that: In step (4), the group VIB metal is molybdenum and / or tungsten, and the group VIII metal is cobalt and / or nickel.

20. The method according to claim 1, characterized in that: In step (4), the active metal component introduced into the modified alumina in step (3) is impregnated by means of equal volume impregnation or over-volume impregnation.

21. The method according to claim 1, characterized in that: In step (4), the drying temperature is 100-160℃ and the drying time is 1.0-8.0 hours.

22. A hydrotreating catalyst prepared by any one of claims 1-21, characterized in that: The hydrogenation catalyst contains 14%-30% by mass of Group VIB metals as oxides, 2%-7% by mass of Group VIII metals as oxides, 1.0%-15.0% by mass of elemental fluorine, and the remainder is a support.

23. The catalyst according to claim 22, characterized in that: The hydrogenation catalyst contains 18%-25% by mass of Group VIB metals as oxides, 3%-6% by mass of Group VIII metals as oxides, 2.0%-10.0% by mass of elemental fluorine, and the remainder is a support.

24. The catalyst according to claim 22, characterized in that: The group VIB metal element is molybdenum, with a mass content of 14%-30% as MoO3; the group VIII metal element is nickel, with a mass content of 2%-7% as NiO.

25. The catalyst according to claim 22, characterized in that: The group VIB metal element is molybdenum, with a mass content of 18%-25% as MoO3; the group VIII metal element is nickel, with a mass content of 3%-6% as NiO.

26. The application of the hydrotreating catalyst according to any one of claims 22-25, characterized in that: The operating conditions are as follows: reaction temperature 250-450℃, reaction pressure 3.0-25.0 MPa, and liquid hourly space velocity 0.2-2.5 h⁻¹. -1 .

27. The application according to claim 26, characterized in that: The properties of the feedstock are as follows: the 95% distillation point of the oil is 450-700℃, the nitrogen content in the oil is 200-3000 μg / g, the sulfur content is 1.0-4.0wt%, and the aromatic content is 30-70wt%.

28. The application according to claim 27, characterized in that: The properties of the feedstock oil are as follows: the 95% distillation point of the oil is 500℃-650℃.

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