Selective hydrogenation catalysts, methods for making and using the same

Abstract

This invention discloses a selective hydrogenation catalyst, its preparation method, and its applications. The selective hydrogenation catalyst of this invention comprises a support, an active component, and an auxiliary agent. The active component includes tungsten oxide and rhenium heptaoxide, and the auxiliary agent includes iron and an organic complexing agent. This selective hydrogenation catalyst ensures the hydrogenation of C=C double bonds or olefins while preventing hydrogenation saturation of aromatic rings or aromatic hydrocarbons, and also possesses strong hydrodesulfurization performance.

Description

Technical Field

[0001] This invention relates to a hydrogenation catalyst and its preparation method, specifically to a selective hydrogenation catalyst, its preparation method, and its application. Background Technology

[0002] In the petrochemical industry, it is common to encounter situations where olefins and aromatics coexist in secondary processing feedstocks, or where an aromatic olefin co-chain hydrocarbon contains both C=C double bonds and aromatic rings. Due to production needs, it is sometimes necessary to hydrogenate the olefins or C=C double bonds while retaining the aromatic or aromatic ring structure. In such cases, it is particularly important whether the catalyst selected has a better selective hydrogenation capability for olefins or carbon-carbon double bonds.

[0003] CN101300213A discloses a selective hydrogenation catalyst for olefins and its application. The method involves reacting a hydrocarbon feedstock containing olefins and aromatic compounds with a Ni-based catalyst at a relatively low temperature and a low stoichiometric ratio of hydrogen to olefins, followed by recovery of the hydrocarbon product stream containing aromatic compounds with a reduced olefin concentration. This method features a simple process and catalyst, and good hydrogenation effect on olefins; however, the proportion of aromatic hydrocarbons in the feedstock is relatively high, resulting in significant losses.

[0004] CN102911721A discloses a method for selective hydrotreating of reformed oil using a liquid-phase circulating process to remove olefins. This method involves hydrogen saturation in a pipeline, followed by the fractional feeding of the liquid mixture into a multi-stage conventional hydrotreating reactor. The mixture then fractionally enters a catalyst bed zone for reaction. The post-reaction products exiting the bottom of the reactor are partially recycled and mixed with fresh feedstock, while a portion is discharged from the reaction system to a subsequent separation unit. While this method exhibits high retention of aromatics, it has poor olefin hydrogenation saturation capabilities.

[0005] CN108359495A discloses a method for upgrading high-olefin catalytic cracking gasoline. The method first pre-hydrogenates the catalytic cracking gasoline to obtain pre-hydrogenated catalytic cracking gasoline; then, it divides the pre-hydrogenated catalytic cracking gasoline into light, middle, and heavy fractions; the light olefins are subjected to catalytic cracking reprocessing or selective hydrodesulfurization; finally, the heavy fraction and sulfur-rich oil are subjected to selective hydrodesulfurization to obtain a desulfurized heavy fraction. While this method can increase the octane number of gasoline products while reducing sulfur and olefin content, it still exhibits a strong hydrosaturation effect on aromatics in the oil.

[0006] It is evident that simply optimizing the process route is insufficient to simultaneously achieve saturated hydrogenation of olefins and maximize the retention of aromatics. Therefore, targeted modification of the hydrogenation catalyst can improve the retention rate of aromatics while saturating olefins with hydrogenation. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a selective hydrogenation catalyst, its preparation method, and its applications. The selective hydrogenation catalyst of this invention ensures the hydrogenation of C=C double bonds (or olefins) while preventing the hydrogenation saturation of aromatic rings (or aromatic hydrocarbons), and also possesses strong hydrodesulfurization performance.

[0008] The first aspect of the present invention provides a selective hydrogenation catalyst, wherein the selective hydrogenation catalyst comprises a support, an active component and an auxiliary agent, the active component comprises tungsten oxide and rhenium heptaoxide, and the auxiliary agent comprises iron and an organic complexing agent.

[0009] Furthermore, the support is alumina. The properties of the support are as follows: specific surface area of ​​250-400 m² / g. 2 / g, pore volume 0.6-0.9cm 3 / g.

[0010] Further, the organic complexing agent is an o-phenanthroline compound. The o-phenanthroline compound includes one or more of the following: 1,10-phenanthroline, 2,9-dimethyl-1,10-o-phenanthroline, 1,10-phenanthroline-5,6-dione, 5,6-diamino-1,10-o-phenanthroline, 5,6-dimethyl-o-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and 4,7-diphenyl-1,10-phenanthroline.

[0011] Furthermore, based on the weight of the selective hydrogenation catalyst, the content of the support is 60%-85%, preferably 65%-80%, the content of tungsten oxide is 5%-20%, preferably 8%-16%, the content of rhenium heptaoxide is 1%-8%, preferably 2%-6%, the content of Fe as Fe2O3 is 1%-5%, preferably 2%-4%, and the content of organic complexing agent is 4%-16%, preferably 6%-12%.

[0012] Furthermore, the selective hydrogenation catalyst is a catalyst used for the selective hydrogenation of olefins and / or the selective hydrogenation of carbon-carbon double bonds in aromatic co-chain hydrocarbons.

[0013] A second aspect of the present invention provides a method for preparing the above-mentioned selective hydrogenation catalyst, comprising:

[0014] (1) Prepare an impregnation solution I containing tungsten and rhenium, impregnate the carrier, and obtain an intermediate containing tungsten and rhenium;

[0015] (2) Prepare impregnation solution II containing iron and organic complexing agent, impregnate the intermediate obtained in step (1) to obtain selective hydrogenation catalyst.

[0016] Furthermore, in step (1), the carrier can be prepared using conventional methods.

[0017] Further, in step (1), when preparing impregnation solution I, the tungsten-containing precursor and the rhenium-containing precursor are dissolved in water and mixed evenly. The tungsten-containing precursor is such as ammonium metatungstate, and the rhenium-containing precursor is such as perrhenic acid.

[0018] Further, in step (1), the molar concentration of tungsten in the impregnation solution I is 0.2-1.5 mol / L, preferably 0.4-1.2 mol / L, and the molar concentration of rhenium is 0.1-0.5 mol / L, preferably 0.15-0.4 mol / L.

[0019] Furthermore, in step (1), the impregnation can be carried out using conventional impregnation methods, such as equal volume impregnation.

[0020] Further, in step (1), after impregnation, the material is dried and calcined to obtain an intermediate containing tungsten and rhenium. The drying temperature is 100-180℃, preferably 120-160℃, and the drying time is 1.0-8.0 hours, preferably 2.0-6.0 hours. The calcination temperature is 350-650℃, preferably 450-550℃, and the calcination time is 1.0-6.0 hours, preferably 2.0-5.0 hours.

[0021] Further, in step (2), when preparing impregnation solution II, the iron-containing precursor and the organic complexing agent are dissolved in an aqueous solution of ethanol and / or acetone, and then heated to obtain impregnation solution II. The heating treatment time is 1.0-10.0 hours, preferably 2.0-6.0 hours, and the heating treatment temperature is 40-120°C, preferably 50-100°C. In the aqueous solution of ethanol and / or acetone, the mass ratio of water to ethanol and / or acetone is 0.5:1-2:1. The iron-containing precursor is an organic iron salt, preferably one or more of ferric acetate, ferrous acetate, ferrous citrate, ferric citrate, ferrous lactate, ferric acetylacetone, and ferrocene.

[0022] Further, in step (2), the mass concentration of the iron-containing precursor in the impregnation solution II is 50-300 g / L, preferably 100-250 g / L, and the mass concentration of the organic complexing agent is 50-300 g / L, preferably 100-200 g / L.

[0023] Furthermore, in step (2), the impregnation can be performed using conventional impregnation methods, such as equal-volume impregnation.

[0024] Further, in step (2), after impregnation, the catalyst is dried to obtain a selective hydrogenation catalyst. The drying temperature is 100-180℃, preferably 120-160℃, and the drying time is 2-8 hours, preferably 3-6 hours.

[0025] A third aspect of the present invention provides an application of the above-mentioned selective hydrogenation catalyst in selective hydrogenation.

[0026] Furthermore, the application is to use the above-mentioned selective hydrogenation catalyst to process aromatic olefin co-chain hydrocarbons that simultaneously have carbon-carbon double bonds and aromatic rings, or feedstock oils that simultaneously contain olefins and aromatics.

[0027] Furthermore, the feedstock oil may be at least one of the following: catalytic cracking slurry oil, catalytic cracking light cycle oil, coking wax oil, coal tar, and deactivated residue hydrogen donor.

[0028] Furthermore, the raw oil may contain impurities such as sulfur (0-3000 μg / g) and nitrogen (0-500 μg / g).

[0029] Furthermore, the selective hydrogenation reaction conditions are as follows: reaction temperature of 200-300℃, preferably 240-280℃, hydrogen pressure of 1.0-6.0 MPa, preferably 2.0-5.0 MPa, and liquid hourly space velocity of 1.0-6.0 h⁻¹. -1 Preferably 2.0-4.0h -1 The hydrogen-to-oil volume ratio is 100:1-600:1, preferably 200:1-400:1.

[0030] Furthermore, the selective hydrogenation catalyst needs to be sulfided before use.

[0031] Furthermore, the vulcanization treatment generally employs a wet vulcanization process. The vulcanizing solution used in the vulcanization treatment comprises a sulfur-containing compound and an organic solvent, wherein the sulfur-containing compound is at least one selected from dimethyl disulfide, carbon disulfide, diethyl sulfide, ethanethiol, n-butanethiol, di-tert-methyl polysulfide, and dimethyl sulfoxide. The organic solvent is at least one selected from cyclohexane, n-heptane, aviation kerosene, and diesel fuel. The mass fraction of the sulfur-containing compound in the vulcanizing solution is 0.5%-3%, preferably 1%-3%, and the flow rate of the vulcanizing solution is 0.5-4.0 mL·h. -1 ·g -1 Oxidized catalyst, preferably 1.0-4.0 mL·h -1 ·g -1 Oxidized catalyst.

[0032] Furthermore, the pressure of the vulcanization treatment is 1.0-4.0 MPa, preferably 1.5-3.0 MPa. The vulcanization treatment is preferably divided into two temperature stages: the first stage temperature is 210℃-250℃ and the vulcanization time is 2.0-10.0 hours; the second stage vulcanization temperature is 300-370℃ and the vulcanization time is 3.0-8.0 hours.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] This invention relates to a selective hydrogenation catalyst. After sulfidation, the +4 valence hexacoordinate W atoms form the main structure of WS2, while the +7 valence Re atoms modify the WS2 active phase, improving the dispersion of the active phase. This also limits the activation and hydrogen transfer capabilities of the active phase, preventing hydrogenation of aromatic rings at low temperatures. The iron-containing complex formed by iron and the organic complexing agent in the catalyst exhibits strong structural stability, effectively delaying the sulfidation of Fe and ensuring that Fe is highly dispersed at the edges and corners of the active phase after the complete formation of Re-WS2. Simultaneously, the combination of Fe with a specific organic complexing agent increases the molecular size of organic Fe and the distance between Fe atoms, preventing the strong hydrogenation activity provided by the high density of Fe atoms at the edges and corners of the active phase from causing hydrogenation saturation of aromatic rings during the reaction. Furthermore, the highly dispersed Fe atoms exhibit strong adsorption selectivity for C=C double bonds, ensuring timely desorption of the product after preferential hydrogenation of C=C double bonds by the active phase, thus avoiding over-reaction. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments, but it should be understood that the scope of protection of the present invention is not limited to the embodiments. In the present invention, unless otherwise expressly stated, percentages and contents are all expressed by mass.

[0036] Example 1

[0037] Preparation of the carrier: Weigh 1000.0g of dry adhesive powder, add 20.0g of citric acid and 10.0g of guar gum powder, mix well, and then add 1000.0g of an aqueous solution containing 5.0% acetic acid. After rolling for 30.0min, extrude the mixture into strips using a 2.0mm diameter clover perforated plate. Dry at 120℃ for 4.0h, then calcine at 700℃ for 5.0h. The calcined carrier is designated as S-0. The specific surface area of ​​carrier S-0 was measured to be 283.1m². 2 / g, the pore volume of the carrier is 0.87cm³. 3 / g.

[0038] Catalyst preparation: Weigh 40.0g ammonium metatungstate and 14.0g perrhenic acid, and dilute to 200mL with deionized water. The resulting solution is denoted as AQ-1.

[0039] Take 200.0g of S-0, impregnate S-0 with AQ-1, then dry at 120℃ for 4.0 hours, and calcine at 500℃ for 4.0 hours to obtain the catalyst intermediate, denoted as M-1.

[0040] Take 30.0 g of ferrous citrate and 25.0 g of 1,10-phenanthroline, dissolve them in 180 mL of a water-ethanol mixture (water to ethanol mass ratio of 1:1.5), and heat at 80 °C in a sealed container for 4.0 hours. The resulting solution is denoted as FQ-1. Impregnate M-1 with FQ-1 and dry at 150 °C for 4.0 hours. The resulting catalyst is denoted as Cat-1.

[0041] Example 2

[0042] The preparation process of carrier S-0 is the same as in Example 1.

[0043] Catalyst preparation: Weigh 50.0g ammonium metatungstate and 18.0g perrhenic acid, and dilute to 200mL with deionized water. The resulting solution is denoted as AQ-2.

[0044] Take 200.0g of S-0, impregnate S-0 with AQ-2, then dry at 120℃ for 4.0 hours, and calcine at 500℃ for 4.0 hours to obtain the catalyst intermediate, denoted as M-2.

[0045] 40.0 g of ferrous lactate and 30.0 g of 2,9-dimethyl-1,10-o-phenanthroline were dissolved in 180 mL of a water-ethanol mixture (water to ethanol mass ratio 1:1). The mixture was heated at 100 °C in a sealed container for 3.0 hours. The resulting solution was designated FQ-2. M-2 was impregnated with FQ-2 and dried at 130 °C for 5.0 hours. The resulting catalyst was designated Cat-2.

[0046] Example 3

[0047] The preparation process of carrier S-0 is the same as in Example 1.

[0048] Catalyst preparation: Weigh 60.0g ammonium metatungstate and 20.0g perrhenic acid, and dilute to 200mL with deionized water. The resulting solution is denoted as AQ-3.

[0049] Take 200.0g of S-0, impregnate S-0 with AQ-3, then dry at 120℃ for 4.0 hours, and calcine at 500℃ for 4.0 hours to obtain the catalyst intermediate, denoted as M-3.

[0050] Take 50.0 g of ferric acetylacetone and 35.0 g of 5,6-diamino-1,10-o-phenanthroline, dissolve them in 180 mL of a water-acetone mixed solution (water to acetone mass ratio of 1:0.5), and heat at 70 °C in a sealed container for 3.0 hours. The resulting solution is designated as FQ-3. Impregnate M-3 with FQ-3 and dry at 120 °C for 4.0 hours. The resulting catalyst is designated as Cat-3.

[0051] Example 4

[0052] The preparation process of carrier S-0 is the same as in Example 1.

[0053] Catalyst preparation: Weigh 70.0 g ammonium metatungstate and 22.0 g perrhenic acid, and dilute to 200 mL with deionized water. The resulting solution is denoted as AQ-4.

[0054] Take 200.0g of S-0, impregnate S-0 with AQ-4, then dry at 120℃ for 4.0 hours, and calcine at 500℃ for 4.0 hours to obtain the catalyst intermediate, denoted as M-4.

[0055] Take 50.0 g of ferric acetate and 40.0 g of 1,10-phenanthroline-5,6-dione, dissolve them in 180 mL of a water-acetone mixture (water to acetone mass ratio of 1:1.0), and heat at 70 °C in a sealed container for 4.0 hours. The resulting solution is designated as FQ-4. Impregnate M-4 with FQ-4 and dry at 120 °C for 4.0 hours. The resulting catalyst is designated as Cat-4.

[0056] Comparative Example 1

[0057] The preparation process of carrier S-0 is the same as in Example 1.

[0058] Weigh 35.0g of ammonium metatungstate and 40.0g of nickel nitrate hexahydrate, and dilute to 200ml with deionized water. The resulting solution is denoted as DQ-1.

[0059] 200.0 g of S-0 was impregnated with DQ-1, then dried at 120°C for 4.0 hours and calcined at 500°C for 4.0 hours to obtain the catalyst, denoted as DCT-1.

[0060] Comparative Example 2

[0061] The preparation process of carrier S-0 is the same as in Example 1.

[0062] Weigh out 45.0g ammonium metatungstate, 15.0g perrhenic acid, and 60.0g ferric nitrate nonahydrate, and dilute to 200ml with deionized water. The resulting solution is denoted as DQ-2.

[0063] 200.0 g of S-0 was impregnated with DQ-2, then dried at 120°C for 4.0 hours and calcined at 500°C for 4.0 hours to obtain the catalyst, denoted as DCT-2.

[0064] Table 1 Catalyst composition

[0065]

[0066] The catalysts obtained in Examples 1-4 and Comparative Examples 1-2 were subjected to sulfidation treatment, as detailed below:

[0067] Prepare a 2 wt% DMDS (dimethyl disulfide) solution in cyclohexane, with a sulfidation liquid flow rate of 2.0 mL / h. -1 ·g -1 Oxidized catalyst.

[0068] The pressure during vulcanization is 2.0 MPa. Vulcanization is divided into two temperature stages: the first stage temperature is 230℃ and the vulcanization time is 4.0 hours; the second stage vulcanization temperature is 320℃ and the vulcanization time is 4.0 hours.

[0069] Examples 5-8

[0070] Evaluation experiments were conducted on the sulfided catalysts of Examples 1-4, respectively, at a reaction temperature of 260°C, a hydrogen pressure of 2.5 MPa, and a liquid hourly space velocity of 3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300:1.

[0071] The composition of the feedstock is shown in Table 2, and the evaluation and analysis results are shown in Table 3.

[0072] Comparative Examples 3-4

[0073] Evaluation experiments were conducted on the sulfidated catalysts of Comparative Examples 1 and 2, respectively, at a reaction temperature of 300℃, a hydrogen pressure of 3.0 MPa, and a liquid hourly space velocity of 2.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300:1.

[0074] The composition of the feedstock is shown in Table 2, and the evaluation and analysis results are shown in Table 3.

[0075] Table 2 Composition of Feedstock Oil

[0076] composition Content, wt% styrene 50 Phenylacetylene 50

[0077] Table 3 Evaluation Results

[0078] Product composition, wt% Cat-1 Cat-2 Cat-3 Cat-4 DCT-1 DCT-2 styrene 6.2 4.3 3.0 1.9 0.2 3.4 Phenylacetylene 6.9 4.1 2.7 1.6 0.3 3.6 Ethylbenzene / Xylene 43.7 45.4 46.2 45.3 26.2 36.9 propylbenzene / isopropylbenzene 42.9 45.1 46.3 45.9 23.8 38.0 Ethylcyclohexane 0.1 0.3 0.8 2.8 23.6 9.7 Propylcyclohexane 0.2 0.8 1.0 2.5 25.9 8.4 Effective conversion rate, % 86.6 90.5 92.5 91.2 50.0 74.9

[0079] As can be seen from the evaluation results in Table 3, the catalyst of the present invention has a strong selective hydrogenation saturation capability for C=C double bonds in hydrocarbons with aromatic rings and double bonds, and the effective hydrogenation rate for C=C double bonds exceeds 85%.

Claims

1. A selective hydrogenation catalyst, characterized in that, The selective hydrogenation catalyst includes a support, an active component, and an auxiliary agent. The active component includes tungsten oxide and rhenium heptaoxide, and the auxiliary agent includes iron and an organic complexing agent. The organic complexing agent is an o-phenanthroline compound; the o-phenanthroline compound includes one or more of the following: 1,10-phenanthroline, 2,9-dimethyl-1,10-o-phenanthroline, 1,10-phenanthroline-5,6-dione, 5,6-diamino-1,10-o-phenanthroline, 5,6-dimethyl-o-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and 4,7-diphenyl-1,10-phenanthroline; The selective hydrogenation catalyst is prepared by the following method, including: (1) Prepare an impregnation solution I containing tungsten and rhenium, impregnate the carrier, and after impregnation, dry and calcine to obtain an intermediate containing tungsten and rhenium; (2) Prepare impregnation solution II containing iron and organic complexing agent, impregnate the intermediate obtained in step (1), and after impregnation, dry to obtain selective hydrogenation catalyst; In step (2), when preparing impregnation solution II, the iron-containing precursor and organic complexing agent are dissolved in an aqueous solution of ethanol and / or acetone and heated to obtain impregnation solution II.

2. The selective hydrogenation catalyst according to claim 1, characterized in that, The carrier is alumina, and the carrier has the following properties: specific surface area of ​​250-400 m². 2 / g, pore volume 0.6-0.9 cm³ 3 / g.

3. The selective hydrogenation catalyst according to claim 1, characterized in that, Based on the weight of the selective hydrogenation catalyst, the content of the support is 60%-85%, the content of tungsten oxide is 5%-20%, the content of rhenium heptaoxide is 1%-8%, the content of Fe as Fe2O3 is 1%-5%, and the content of organic complexing agent is 4%-16%.

4. The selective hydrogenation catalyst according to claim 3, characterized in that, Based on the weight of the selective hydrogenation catalyst, the content of the support is 65%-80%, the content of tungsten oxide is 8%-16%, the content of rhenium heptaoxide is 2%-6%, the content of Fe as Fe2O3 is 2%-4%, and the content of organic complexing agent is 6%-12%.

5. A method for preparing a selective hydrogenation catalyst according to any one of claims 1-4, comprising: (1) Prepare an impregnation solution I containing tungsten and rhenium, impregnate the carrier, and after impregnation, dry and calcine to obtain an intermediate containing tungsten and rhenium; (2) Prepare impregnation solution II containing iron and organic complexing agent, impregnate the intermediate obtained in step (1), and after impregnation, dry to obtain selective hydrogenation catalyst; In step (2), when preparing impregnation solution II, the iron-containing precursor and organic complexing agent are dissolved in an aqueous solution of ethanol and / or acetone and heated to obtain impregnation solution II.

6. The method according to claim 5, characterized in that: In step (1), the molar concentration of tungsten in impregnation solution I is 0.2-1.5 mol / L and the molar concentration of rhenium is 0.1-0.5 mol / L.

7. The method according to claim 6, characterized in that: In step (1), the molar concentration of tungsten in impregnation solution I is 0.4-1.2 mol / L and the molar concentration of rhenium is 0.15-0.4 mol / L.

8. The method according to claim 5, characterized in that: The heating treatment time in step (2) is 1.0-10.0 hours and the heating treatment temperature is 40-120℃; in the aqueous solution of ethanol and / or acetone, the mass ratio of water to ethanol and / or acetone is 0.5:1-2:

1.

9. The method according to claim 8, characterized in that: The heating treatment time in step (2) is 2.0-6.0 hours, and the heating temperature is 50-100℃.

10. The method according to claim 5, characterized in that: The iron-containing precursor is an organic iron salt.

11. The method according to claim 10, characterized in that: The iron-containing precursor is one or more of ferric acetate, ferrous acetate, ferrous citrate, ferrous citrate, ferrous lactate, ferric acetylacetone, and ferrocene.

12. The method according to claim 5, characterized in that: In step (2), the mass concentration of the iron-containing precursor in impregnation solution II is 50-300 g / L, and the mass concentration of the organic complexing agent is 50-300 g / L.

13. The method according to claim 12, characterized in that: In step (2), the mass concentration of the iron-containing precursor in impregnation solution II is 100-250 g / L, and the mass concentration of the organic complexing agent is 100-200 g / L.

14. The method according to claim 5, characterized in that: In step (2), the drying temperature is 100-180ºC and the drying time is 2-8 hours.

15. The method according to claim 14, characterized in that: In step (2), the drying temperature is 120-160ºC and the drying time is 3-6 hours.

16. The use of the selective hydrogenation catalyst according to any one of claims 1-4 or the selective hydrogenation catalyst prepared according to any one of claims 5-15 in selective hydrogenation.

17. The application according to claim 16, characterized in that: The selective hydrogenation catalyst is used to process aromatic olefin co-chain hydrocarbons that simultaneously have carbon-carbon double bonds and aromatic rings, or feedstock oils that simultaneously contain olefins and aromatics.

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