Ag-modified hydrogenation catalyst, its preparation and use

Abstract

This invention discloses an Ag-modified hydrogenation catalyst, its preparation method, and its application. The preparation method of the Ag-modified hydrogenation catalyst of this invention includes: (1) sulfiding an oxidized hydrogenation catalyst to obtain a sulfidated hydrogenation catalyst; (2) desulfurizing the sulfidated hydrogenation catalyst obtained in step (1); and (3) introducing an organic solution containing Ag into the catalyst treated in step (2) to carry out a reaction, thereby obtaining the Ag-modified hydrogenation catalyst. The Ag-modified hydrogenation catalyst of this invention still exhibits good stability under low-sulfur conditions, and is particularly suitable for long-term processing of low-sulfur or sulfur-free raw materials.

Description

Technical Field

[0001] This invention relates to a method for preparing a hydrogenation catalyst, and particularly to an Ag-modified hydrogenation catalyst, its preparation method, and its applications. Background Technology

[0002] Biomass oils, Fischer-Tropsch synthesis oils, and most C1 chemically synthesized oils often contain small amounts of sulfur or none at all. This leads to a decrease in catalyst activity during processing, as conventional sulfur-containing hydrogenation catalysts experience reduction of sulfide metals due to the consistently low sulfur content in the reaction atmosphere. Therefore, sulfur fixation in nickel-molybdenum catalysts is a major challenge in their application.

[0003] CN103788997A discloses a method for treating low-sulfur, high-nitrogen catalysts. This method premixes a portion of hydrogen sulfide to ensure the concentration of hydrogen sulfide while maintaining catalyst activity. This method effectively removes metallic impurities from the feedstock, and for low-sulfur, high-nitrogen hydrocracking feedstocks, it eliminates the need for sulfiding agent replenishment. CN103789030A discloses a hydrocracking method for low-sulfur feedstocks. This method maintains the sulfur content of the feedstock by mixing water containing dissolved hydrogen sulfide with the material entering the cold high-pressure fraction. This method is mainly used in hydrocracking processes that produce high-quality petroleum products from various low-sulfur distillate oils. CN102465014A discloses a hydrocracking method for low-sulfur feedstocks. This method effectively combines the hydrogen-rich gases from the hydrotreatment and hydrocracking processes, fully utilizing the sulfur-containing hydrogen-rich gas from the hydrotreatment process to replenish sulfur in the low-sulfur feedstock hydrocracking unit, effectively solving the catalyst sulfur loss problem during long-term operation of the low-sulfur hydrocracking unit.

[0004] However, the aforementioned process requires a certain amount of sulfur in the feedstock to maintain the normal hydrogen sulfide partial pressure in the reaction system. For systems with very low sulfur content, maintaining long-term stability is difficult. When processing unconventional oils, many low-sulfur or sulfur-free feedstocks are encountered. During the processing of these feedstocks, the low-coordinated sulfur on the surface of the Ni-Mo-S active phase of the catalyst is rapidly lost, resulting in significant loss of hydrogenation catalyst activity. Therefore, developing a catalyst for the effective hydrogenation of low-sulfur oils is an urgent problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an Ag-modified hydrogenation catalyst, its preparation method, and its applications. The Ag-modified hydrogenation catalyst prepared by the method of this invention maintains good stability under low-sulfur conditions, making it particularly suitable for long-term processing of low-sulfur or sulfur-free feedstocks.

[0006] The first aspect of this invention provides a method for preparing an Ag-modified hydrogenation catalyst, the method comprising:

[0007] (1) Sulfide the oxidized hydrogenation catalyst to obtain the sulfide hydrogenation catalyst;

[0008] (2) The sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment;

[0009] (3) Pass an organic solution containing Ag into the catalyst treated in step (2) to carry out the reaction and obtain the Ag-modified hydrogenation catalyst.

[0010] Further, in step (1), the oxidized hydrogenation catalyst comprises: a support, active metal molybdenum, and nickel. Based on the mass of the catalyst, the content of the support is 50%-85%, the content of molybdenum as oxide is 10%-40%, and the content of nickel as oxide is 2%-10%.

[0011] Further, in step (1), the support in the oxidized hydrogenation catalyst is at least one of alumina, silicon oxide, amorphous silica-alumina, etc.; the support may be doped with one or more of the modifying elements such as phosphorus, silicon, boron, fluorine, and sodium. The amount of the modifying element added is conventional, preferably 0.5%-6.0% of the support mass.

[0012] Furthermore, in step (1), the oxidized hydrogenation catalyst is a catalyst with heavy oil hydrogenation function, which can be prepared by conventional methods in the art or a commercially available catalyst can be purchased.

[0013] Further, in step (1), the sulfidation is full sulfidation, meaning the active metal in the oxidized hydrogenation catalyst reaches a state of complete sulfidation, which can be achieved using sulfidation methods known in the art. For example, the sulfidation conditions are as follows: sulfidation temperature of 240-400℃, preferably 300-380℃, sulfidation time of 3-8h, hydrogen pressure of 2.0-12.0MPa, preferably 3.0-8.0MPa, and hydrogen flow rate of 2.0-15.0mL·min. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 3.0-15.0 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

[0014] Further, in step (1), the sulfiding liquid used for sulfidation includes a sulfur-containing compound and an organic solvent. The sulfur-containing compound is one or more of dimethyl disulfide, carbon disulfide, diethyl sulfide, ethanethiol, n-butanethiol, di-tert-methyl polysulfide, and dimethyl sulfoxide. The organic solvent is one or more of cyclohexane, n-heptane, aviation kerosene, and diesel oil. The mass fraction of the sulfur-containing compound in the sulfiding liquid is 2%-6%, preferably 4%-6%. The flow rate of the sulfiding liquid is 0.5-5.0 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 1.0-4.0 mL·h -1 ·g -1 Oxidized hydrogenation catalyst.

[0015] Furthermore, in step (2), the desulfurization treatment is a mild desulfurization treatment, carried out in at least one of the following ways:

[0016] (a) The sulfided hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment using hydrogen gas containing hydrogen sulfide;

[0017] (b) In the presence of hydrogen, the sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment with a sulfurized liquid.

[0018] Further, in step (2), the conditions for the desulfurization treatment are as follows: the treatment temperature is 180-370℃, preferably 200-300℃, the treatment time is 4-24 hours, preferably 6-16 hours, and the total pressure is 2.0-18.0MPa, preferably 4.0-15.0MPa.

[0019] Further, in method (a), the volume ratio of hydrogen to hydrogen sulfide is 200:1-800:1, preferably 300:1-600:1, and the total gas flow rate is 5-30 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 10-20 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

[0020] Further, in method (b), the sulfiding liquid includes a sulfur-containing compound and an organic solvent, wherein the sulfur-containing compound is one or more of dimethyl disulfide, carbon disulfide, diethyl sulfide, ethanethiol, n-butanethiol, di-tert-methyl polysulfide, and dimethyl sulfoxide, and the organic solvent is one or more of cyclohexane, n-heptane, aviation kerosene, and diesel oil; the mass fraction of the sulfur-containing compound in the sulfiding liquid is 0.1%-0.6%. During the desulfurization process, the amount of sulfiding liquid used is 0.2-2.0 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 0.4-1.5 mL·h-1 ·g -1 Oxidized hydrogenation catalyst, hydrogen flow rate 5-30 mL·min -1 ·g -1 Oxidized hydrogenation catalyst, preferably 10-20 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

[0021] Further, in step (3), the solvent in the organic solution containing Ag is one or more of toluene, cyclohexane, decahydronaphthalene, tetrahydronaphthalene, and n-heptane, and the Ag-containing compound is one or more of silver stearate, silver acetylacetone, and silver cyclohexanebutyrate. The mass fraction of the Ag-containing compound in the organic solution is 2%-8%, preferably 3%-6%. The flow rate of the organic solution containing Ag is 2-10 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 3-8 mL·h -1 ·g -1 Oxidized hydrogenation catalyst.

[0022] Further, in step (3), the reaction conditions are as follows: temperature is 80-200℃, preferably 100-160℃; time is 5-20 hours, preferably 6-15 hours; hydrogen pressure is 0.2-4.0 MPa, preferably 0.5-2.0 MPa; hydrogen flow rate is 2-20 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 5-15 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

[0023] A second aspect of the present invention provides an Ag-modified hydrogenation catalyst prepared by the above method, wherein the Ag-modified hydrogenation catalyst is a sulfide-state catalyst, comprising a support and active metals Mo and Ni, and further comprising Ag, wherein, characterized by TEM-EDS, the Ag content distributed in the Ni-Mo-S active phase region accounts for 60%-95% of the total Ag content, preferably 75%-95%.

[0024] Furthermore, in the Ag-modified hydrogenation catalyst, the sulfur content at the corner sites of the Ni-Mo-S active phase, characterized by TEM-EDS, is less than 6.0% of the total sulfur content in the Ni-Mo-S active phase, and further is 1.0%-3.0%.

[0025] Furthermore, the Ag-modified hydrogenation catalyst, based on the mass of the Ag-modified hydrogenation catalyst, has a molybdenum content (Mo) of 10%-24%, preferably 13%-20%, and a nickel content (Ni) of 1.0%-10%, preferably 3.0%-6.0%.

[0026] Furthermore, the Ag-modified hydrogenation catalyst, based on the mass of the Ag-modified hydrogenation catalyst, has an Ag element content of 0.2%-2.0%, preferably 0.8-2.0%.

[0027] Furthermore, the Ag-modified hydrogenation catalyst, based on the mass of the Ag-modified hydrogenation catalyst, has a sulfur content of 5%-20%, preferably 8%-15%.

[0028] Furthermore, the Ag-modified hydrogenation catalyst, based on the mass of the Ag-modified hydrogenation catalyst, has a support content of 50%-80%, preferably 55%-75%.

[0029] A third aspect of the present invention provides the application of the above-mentioned Ag-modified hydrogenation catalyst in the hydrogenation of low-sulfur oil products.

[0030] Furthermore, the sulfur content of the low-sulfur oil is less than 200 μg / g. The low-sulfur oil includes, but is not limited to, at least one of biodiesel, Fischer-Tropsch synthetic oil, and low-temperature coal tar.

[0031] Furthermore, the application conditions are as follows: reaction temperature of 250-400℃, reaction pressure of 4.0-20.0 MPa, and volume hourly space velocity of 0.2-5.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 400:1-1000:1.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] This invention first sulfides and desulfurizes the oxidized hydrogenation catalyst, so that the metal active phase to be modified is in a specific desulfurized high-activity state. The outer layer of the active phase edge is an exposed active metal, while effectively retaining the tri-coordinated sulfur atoms and stable Ni-Mo-S crystal structure inside the hydrogenation active phase. This allows the modified Ag element to contact the outer metal phase of the active phase more effectively. Ag, Ni, Mo and S form an Ag-Ni-Mo-S combined mixed active phase.

[0034] The Ag-modified hydrogenation catalyst of this invention is used to hydrogenate olefins, dienes, and aromatics in low-sulfur oil products during processing, as well as to perform hydrodeoxygenation and hydrodecarboxylation. It has good hydrogenation saturation capacity and stable hydrodeoxygenation and hydrodeacidification capabilities, and has the advantage of high stability, making it particularly suitable for long-term operation. 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] In this invention, the Ag-modified hydrogenation catalyst was characterized by TEM-EDS (transmission electron microscopy-energy dispersive X-ray spectroscopy) using an instrument of model JY / T 011-1996, JEM-1400Flash. The determination process is as follows: the catalyst particles were ground and the sample was prepared by suspension method. 0.1g of the catalyst sample was placed in a 2mL container and ultrasonically dispersed with anhydrous ethanol. The supernatant was collected, and two to three drops were taken with a dropper and dropped onto a 3mm diameter sample grid. After drying, the sample to be tested was obtained. Then, the sample to be tested was observed and analyzed by TEM. Combined with EDS, the Ag content distribution was statistically analyzed. The ratio of Ag content distributed in the Ni-Mo-S active phase region to the total Ag content (Ag-Ni-Mo-S / Ag) was obtained based on the corresponding peak area of ​​Ag. 总 (This is an example of how the present invention uses the average value obtained by combining 20 TEM images with EDS analysis.)

[0037] In this invention, the sulfur content at the corner sites of the Ni-Mo-S active phase relative to the total sulfur content in the Ni-Mo-S active phase is characterized using the TEM-EDS method. The instrument used is JY / T 011-1996, JEM-1400Flash. The determination process is as follows: The catalyst particles are ground and the sample is prepared using the suspension method. 0.1g of the catalyst sample is placed in a 2mL container and ultrasonically dispersed with anhydrous ethanol. The supernatant is collected, and two to three drops are taken with a dropper and dropped onto a 3mm diameter sample mesh. After drying, the sample to be tested is obtained. Then, the sample to be tested is observed and analyzed using TEM. Any active phase observed under a TEM microscope is selected, and combined with EDS, the sulfur content at the edge of the active phase (which can be considered the corner sites of the active phase) and the sulfur content in the active phase are statistically analyzed. The sulfur content at the corner sites of the Ni-Mo-S active phase relative to the total sulfur content in the Ni-Mo-S active phase is obtained based on the corresponding peak area of ​​sulfur. (Using S...) 边角位 / S 总 (Represented). This invention uses the average value obtained from 20 TEM images combined with EDS analysis.

[0038] The oxidized hydrogenation catalysts used in the following embodiments and comparative examples of this invention were all prepared by the following methods:

[0039] Weigh 1000.0g of alumina dry adhesive powder, add 30.0g of citric acid and 10.0g of guar gum powder, mix well, then add 900.0g of an aqueous solution containing 2.0% nitric acid. After rolling for 30.0min, extrude the mixture using a 1.6mm diameter clover-shaped perforated plate. Dry at 120℃ for 6.0h, then calcine at 600℃ for 6.0h. The calcined carrier is designated S-0 (the specific surface area of ​​the carrier is 304m²). 2 / g, pore volume 0.75cm 3 Weigh 100.0 g of ammonium heptamolybdate tetrahydrate, 60.0 g of nickel nitrate hexahydrate, and 120.0 g of deionized water. Stir thoroughly at 80 °C for 30 min, cool to room temperature, and then dilute to 180.0 mL with deionized water. The resulting solution is denoted as Q-0. Take 200 g of support S-0, impregnate it with Q-0, air dry for 24 hours, then dry at 120 °C for 4 hours, and then calcine at 420 °C for 4.0 hours. The resulting oxidized hydrogenation catalyst is denoted as CT-0 (based on the mass of the catalyst, the content of the support is 70.2%, the content of molybdenum as oxide is 25.0%, and the content of nickel as oxide is 4.8%).

[0040] Example 1

[0041] Take 1000g of cyclohexane and 50.0g of dimethyl disulfide, and the resulting sulfidation solution is denoted as SQ-0.

[0042] Take 1000g of cyclohexane and 2.0g of dimethyl disulfide, and the resulting sulfidation solution is denoted as TQ-1.

[0043] Take 2000g of toluene and 70.0g of silver stearate, and prepare an organic solution containing silver, denoted as YQ-1.

[0044] Take 20.0g of CT-0 and put it into a reaction tube. Use SQ-0 for sulfidation under the following conditions: sulfidation temperature is 350℃, hydrogen pressure is 6.0MPa, hydrogen flow rate is 300.0mL / min, sulfidation liquid SQ-0 flow rate is 40.0mL / h, and sulfidation time is 6 hours. The resulting sulfided hydrogenation catalyst is denoted as SCT-0.

[0045] The reaction tube temperature was lowered to 260℃, the hydrogen pressure was adjusted to 5.0 MPa, and the hydrogen flow rate was 200.0 mL / min. TQ-1 was introduced into the reaction tube at a flow rate of 30.0 mL / h, and the treatment time was 9 hours. The obtained catalyst was designated TCT-1.

[0046] The reaction tube temperature was lowered to 110℃, the hydrogen pressure was adjusted to 1.0 MPa, and the hydrogen flow rate was 120.0 mL / min. YQ-1 was introduced into the reaction tube at a flow rate of 80.0 mL / h, and the treatment time was 9.0 hours. The resulting catalyst was designated ECT-1.

[0047] Example 2

[0048] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0049] Take 1000g of cyclohexane and 3.0g of carbon disulfide to prepare a sulfidation liquid, which is denoted as TQ-2.

[0050] Take 2000g of toluene and 80.0g of silver acetylacetone, and prepare an organic solution containing silver, denoted as YQ-2.

[0051] The reaction tube temperature was lowered to 280℃, the hydrogen pressure was adjusted to 6.0 MPa, and the hydrogen flow rate was 300.0 mL / min. TQ-2 was introduced into the reaction tube at a flow rate of 40.0 mL / h, and the treatment time was 12 hours. The obtained catalyst was designated TCT-2.

[0052] The reaction tube temperature was lowered to 130℃, the hydrogen pressure was adjusted to 1.5 MPa, and the hydrogen flow rate was 150.0 mL / min. YQ-2 was introduced into the reaction tube at a flow rate of 100.0 mL / h for 12.0 hours. The resulting catalyst was designated ECT-2.

[0053] Example 3

[0054] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0055] Take 1000g of cyclohexane and 4.0g of dimethyl disulfide, and the resulting sulfidation solution is designated as TQ-3.

[0056] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate, and prepare an organic solution containing silver, denoted as YQ-3.

[0057] The reaction tube temperature was lowered to 300℃, the hydrogen pressure was adjusted to 10.0 MPa, and the hydrogen flow rate was 400.0 mL / min. TQ-3 was introduced into the reaction tube at a flow rate of 40.0 mL / h, and the treatment time was 12 hours. The obtained catalyst was designated as TCT-3.

[0058] The reaction tube temperature was lowered to 150℃, the hydrogen pressure was adjusted to 2.0 MPa, and the hydrogen flow rate was 180.0 mL / min. YQ-3 was introduced into the reaction tube at a flow rate of 120.0 mL / h, and the treatment time was 15.0 hours. The obtained catalyst was designated ECT-3.

[0059] Example 4

[0060] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0061] Take 2000g of toluene and 100.0g of silver stearate to prepare an organic solution containing silver, denoted as YQ-4.

[0062] The reaction tube temperature was lowered to 260℃, the reaction pressure was adjusted to 4.0 MPa, and a mixture of hydrogen and hydrogen sulfide was simultaneously introduced. The partial pressure ratio of hydrogen to hydrogen sulfide was 300:1, the flow rate of the mixed gas was 300.0 mL / min, and the treatment time was 12 hours. The resulting catalyst was designated TCT-4.

[0063] The reaction tube temperature was lowered to 140℃, the hydrogen pressure was adjusted to 2.5 MPa, and the hydrogen flow rate was 150.0 mL / min. YQ-4 was introduced into the reaction tube at a flow rate of 100.0 mL / h for 12.0 hours. The resulting catalyst was designated ECT-4.

[0064] Example 5

[0065] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0066] Take 2000g of toluene and 60.0g of silver acetylacetone, and prepare an organic solution containing silver, denoted as YQ-5.

[0067] The reaction tube temperature was lowered to 260℃, the reaction pressure was adjusted to 4.0 MPa, and a mixture of hydrogen and hydrogen sulfide was simultaneously introduced. The partial pressure ratio of hydrogen to hydrogen sulfide was 250:1, the flow rate of the mixed gas was 350.0 mL / min, and the treatment time was 12 hours. The resulting catalyst was designated TCT-5.

[0068] The reaction tube temperature was lowered to 160℃, the hydrogen pressure was adjusted to 3.0 MPa, and the hydrogen flow rate was 160.0 mL / min. YQ-5 was introduced into the reaction tube at a flow rate of 100.0 mL / h, and the treatment time was 12.0 hours. The obtained catalyst was designated ECT-5.

[0069] Comparative Example 1

[0070] 20.0g of CT-0 was loaded into a reaction tube and sulfided using SQ-0. During the sulfidation process, the hydrogen pressure was 6.0MPa, the hydrogen flow rate was 300.0mL / min, the flow rate of the sulfidation liquid SQ-0 was 40.0mL / h, the sulfidation temperature was 350℃, and the sulfidation time was 6.0 hours. The catalyst after sulfidation was designated as DCT-1.

[0071] Comparative Example 2

[0072] The preparation process of catalyst DCT-1 is the same as that of comparative example 1.

[0073] The reaction tube containing DCT-1 was cooled to 260℃, the hydrogen pressure was adjusted to 5.0 MPa, and the hydrogen flow rate was 200.0 mL / min. TQ-1 was then introduced into the reaction tube at a flow rate of 30.0 mL / h for 9 hours. The resulting catalyst was designated DCT-2.

[0074] Comparative Example 3

[0075] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0076] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate, and prepare an organic solution containing silver, denoted as DYQ-3.

[0077] The reaction tube containing SCT-0 was cooled to 150℃, the hydrogen pressure was adjusted to 2.0 MPa, and the hydrogen flow rate was 180.0 mL / min. DYQ-3 was then introduced into the reaction tube at a flow rate of 120.0 mL / h for 15.0 hours. The resulting catalyst was designated DCT-3.

[0078] Comparative Example 4

[0079] The preparation process of catalyst DCT-1 is the same as that of comparative example 1.

[0080] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate to prepare an organic solution containing silver, denoted as DYQ-4.

[0081] The reaction tube containing DCT-1 was cooled to 300℃, the hydrogen pressure was adjusted to 10.0 MPa, the hydrogen flow rate was 400.0 mL / min, and the treatment time was 12 hours. The resulting catalyst was designated DTCT-4.

[0082] The temperature of the reaction tube containing DTCT-4 was reduced to 150℃, the hydrogen pressure was adjusted to 2.0 MPa, and the hydrogen flow rate was 180.0 mL / min. DYQ-4 was then introduced into the reaction tube at a flow rate of 120.0 mL / h for 15.0 hours. The resulting catalyst was designated DCT-4.

[0083] Comparative Example 5

[0084] Weigh 1000.0g of alumina dry adhesive powder, add 30.0g of citric acid and 10.0g of guar gum powder, mix well, then add 900.0g of an aqueous solution containing 2.0% nitric acid by mass. After rolling for 30.0min, extrude the mixture using a 1.6mm diameter clover-shaped perforated plate. Dry at 120℃ for 6.0h, then calcine at 600℃ for 6.0h. The calcined carrier is designated S-0.

[0085] Weigh 100.0g ammonium heptamolybdate tetrahydrate, 60.0g nickel nitrate hexahydrate, 7.5g silver nitrate, and 120.0g deionized water. Stir thoroughly at 80℃ for 30 minutes, cool to room temperature, and then dilute to 180.0mL with deionized water. The resulting solution is denoted as DQ-5.

[0086] Take 200g of carrier S-0, impregnate it with DQ-5, air dry it naturally for 24 hours, then dry it at 120℃ for 4 hours, and then calcine it at 420℃ for 4.0 hours. The resulting oxidized hydrogenation catalyst is denoted as DCT-0.

[0087] 20.0g of DCT-0 was loaded into a reaction tube and sulfided using SQ-0. During the sulfidation process, the hydrogen pressure was 6.0MPa, the hydrogen flow rate was 300.0mL / min, the flow rate of the sulfidation liquid SQ-0 was 40.0mL / h, the sulfidation temperature was 350℃, and the sulfidation time was 6 hours. The resulting sulfided hydrogenation catalyst was designated as DCT-5.

[0088] Table 1. Composition of the catalysts obtained in each example.

[0089]

[0090]

[0091] The hydrogenation catalysts obtained in each example were characterized by TEM-EDS to obtain the percentage of Ag content distributed in the Ni-Mo-S active phase region to the total Ag content, and the percentage of sulfur content at the corner sites of the Ni-Mo-S active phase to the total sulfur content in the Ni-Mo-S active phase. See Table 2 for details.

[0092] Table 2

[0093] Catalyst number ECT-1 ECT-2 ECT-3 ECT-4 ECT-5 DCT-1 DCT-2 DCT-3 DCT-4 DCT-5 <![CDATA[Ag-Ni-Mo-S / Ag 总 ,%]]> 89 84 85 88 90 - - 35 52 29 <![CDATA[S 边角位 / S 总 ,%]]> 2.5 2.6 2.4 2.5 2.6 7.3 1.8 7.9 4.0 7.4

[0094] Examples 6-10

[0095] The activity and stability of catalysts ECT-1 to ECT-5 were investigated in a fixed-bed hydrogenation unit under the following evaluation conditions: reaction pressure 8.0 MPa, hydrogen-to-oil volume ratio 500:1, temperature 300 °C, and volume hourly space velocity 2.0 h⁻¹. -1Samples were taken and analyzed at two time points: 500 hours and 1500 hours of reaction. The feedstock used was Fischer-Tropsch synthetic oil, and its properties are shown in Table 3. The catalyst evaluation results are shown in Table 4.

[0096] Comparative Examples 6-10

[0097] The activity and stability of catalysts DCT-1 to DCT-5 were investigated in a fixed-bed hydrogenation unit, and the evaluation conditions were the same as in Example 6.

[0098] Table 3 Properties of Feed Oil

[0099]

[0100] Table 4 Catalyst Evaluation Results

[0101]

[0102]

[0103] As can be seen from the evaluation results in Table 4, when using the hydrogenation catalyst of this invention to process low-sulfur Fischer-Tropsch synthetic oil, it still exhibits good hydrodeacidification and hydrogenation saturation performance under long-term operation, and maintains good activity stability.

Claims

1. A method for preparing an Ag-modified hydrogenation catalyst, characterized in that, include: (1) Sulfide the oxidized hydrogenation catalyst to obtain the sulfide hydrogenation catalyst, wherein the sulfideing is a complete sulfideing; (2) The sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment, wherein the desulfurization treatment is a mild desulfurization treatment; (3) Pass an organic solution containing Ag into the catalyst treated in step (2) to carry out the reaction and obtain the Ag-modified hydrogenation catalyst.

2. The method according to claim 1, characterized in that: In step (1), the oxidized hydrogenation catalyst includes: a support, active metal molybdenum and nickel; based on the mass of the catalyst, the content of the support is 50%-85%, the content of molybdenum as oxide is 10%-40%, and the content of nickel as oxide is 2%-10%.

3. The method according to claim 1, characterized in that: In step (1), the sulfidation conditions are as follows: sulfidation temperature is 240-400℃, sulfidation time is 3-8h, and during sulfidation, the hydrogen pressure is 2.0-12.0 MPa, and the hydrogen flow rate is 2.0-15.0 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

4. The method according to claim 3, characterized in that: In step (1), the sulfidation is full sulfidation, and the sulfidation conditions are as follows: sulfidation temperature is 300-380℃, and during sulfidation, the hydrogen pressure is 3.0-8.0 MPa, and the hydrogen flow rate is 3.0-15.0 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

5. The method according to claim 1, characterized in that: In step (2), the desulfurization treatment is carried out in one of the following ways: (a) The sulfided hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment using hydrogen gas containing hydrogen sulfide; (b) In the presence of hydrogen, the sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment with a sulfurized liquid.

6. The method according to claim 5, characterized in that: In step (2), the desulfurization treatment conditions are as follows: the treatment temperature is 180-370℃, the treatment time is 4-24 hours, and the total pressure is 2.0-18.0 MPa.

7. The method according to claim 6, characterized in that: In step (2), the desulfurization treatment conditions are as follows: the treatment temperature is 200-300℃, the treatment time is 6-16 hours, and the total pressure is 4.0-15.0 MPa.

8. The method according to claim 5, characterized in that: In method (a), the volume ratio of hydrogen to hydrogen sulfide is 200:1-800:1, and the total gas flow rate is 5-30 mL / min. -1 ·g -1 Oxidized hydrogenation catalyst.

9. The method according to claim 8, characterized in that: In method (a), the volume ratio of hydrogen to hydrogen sulfide is 300:1-600:1, and the total gas flow rate is 10-20 mL / min. -1 ·g -1 Oxidized hydrogenation catalyst.

10. The method according to claim 5, characterized in that: In method (b), the sulfiding liquid comprises a sulfur-containing compound and an organic solvent, wherein the sulfur-containing compound is one or more of dimethyl disulfide, carbon disulfide, diethyl sulfide, ethanethiol, n-butanethiol, di-tert-nonyl polysulfide, and dimethyl sulfoxide, and the organic solvent is one or more of cyclohexane, n-heptane, aviation kerosene, and diesel oil; the mass fraction of the sulfur-containing compound in the sulfiding liquid is 0.1%-0.6%; and the amount of sulfiding liquid used during the desulfurization process is 0.2-2.0 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst, hydrogen flow rate 5-30 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

11. The method according to claim 10, characterized in that: In method (b), the amount of sulfiding liquid used during the desulfurization process is 0.4-1.5 mL / h. -1 ·g -1 Oxidized hydrogenation catalyst, hydrogen flow rate 10-20 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

12. The method according to claim 1, characterized in that: In step (3), the organic solution containing Ag element contains one or more of the following solvents: toluene, cyclohexane, decahydronaphthalene, tetrahydronaphthalene, and n-heptane, and the Ag-containing compound contains one or more of the following: silver stearate, silver acetylacetone, and silver cyclohexanebutyrate.

13. The method according to claim 12, characterized in that: The organic solution containing Ag has an Ag compound mass fraction of 2%-8%, and the flow rate of the organic solution containing Ag is 2-10 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst.

14. The method according to claim 13, characterized in that: The flow rate of the organic solution containing Ag is 3-8 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst.

15. The method according to claim 1, characterized in that: In step (3), the reaction conditions are as follows: temperature 80-200℃, time 5-20 hours; hydrogen pressure 0.2-4.0 MPa; hydrogen flow rate 2-20 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

16. The method according to claim 15, characterized in that: In step (3), the reaction conditions are as follows: temperature 100-160℃, time 6-15 hours; hydrogen pressure 0.5-2.0 MPa; hydrogen flow rate 5-15 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

17. An Ag-modified hydrogenation catalyst prepared according to any one of claims 1-16, characterized in that: The Ag-modified hydrogenation catalyst is a sulfide-state catalyst, comprising a support and active metals Mo and Ni, and also containing Ag. Characterized by TEM-EDS, the Ag content distributed in the Ni-Mo-S active phase region accounts for 60%-95% of the total Ag content.

18. The Ag-modified hydrogenation catalyst according to claim 17, characterized in that: Characterized by TEM-EDS, the Ag content distributed in the Ni-Mo-S active phase region accounts for 75%-95% of the total Ag content.

19. The Ag-modified hydrogenation catalyst according to claim 17, characterized in that: Characterized by TEM-EDS, the sulfur content at the corner sites of the Ni-Mo-S active phase accounts for less than 6.0% of the total sulfur content in the Ni-Mo-S active phase. The sulfur content at the corner sites of the active phase refers to the sulfur content at the edge endpoint of the active phase, which is less than 1 nm away from the edge endpoint.

20. The Ag-modified hydrogenation catalyst according to claim 19, characterized in that: Characterized by TEM-EDS, the sulfur content at the corner sites of the Ni-Mo-S active phase accounts for 1.0%-3.0% of the total sulfur content in the Ni-Mo-S active phase.

21. The Ag-modified hydrogenation catalyst according to claim 17, characterized in that: Based on the mass of Ag-modified hydrogenation catalyst, the content of molybdenum (Mo) is 10%-24%, the content of nickel (Ni) is 1.0%-10%, the content of Ag (Ag) is 0.2%-2.0%, the content of S (S) is 5%-20%, and the content of support is 50%-80%.

22. The Ag-modified hydrogenation catalyst according to claim 21, characterized in that: Based on the mass of the Ag-modified hydrogenation catalyst, the content of molybdenum (Mo) is 13%-20%, the content of nickel (Ni) is 3.0%-6.0%, the content of Ag (Ag) is 0.8%-2.0%, the content of S (S) is 8%-15%, and the content of the support is 55%-75%.

23. The application of the Ag-modified hydrogenation catalyst according to any one of claims 17-22 in the hydrogenation of low-sulfur oil products.

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