Ag modified hydrogenation catalyst and method for preparing the same

Abstract

This invention discloses an Ag-modified hydrogenation catalyst and its preparation method. The Ag-modified hydrogenation catalyst is a sulfide-state catalyst, comprising a support, active metals Mo and Ni, and 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. The Ag-modified hydrogenation catalyst 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.

Description

Technical Field

[0001] This invention relates to a method for preparing a hydrogenation catalyst, and more particularly to an Ag-modified hydrogenation catalyst and its preparation method. 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 and its preparation method. The Ag-modified hydrogenation catalyst 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 the present invention provides an Ag-modified hydrogenation catalyst, 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%.

[0007] 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%.

[0008] 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%.

[0009] 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%.

[0010] 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%.

[0011] 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%.

[0012] Furthermore, in the Ag-modified hydrogenation catalyst, the support is at least one selected from alumina, silicon oxide, and amorphous silica-alumina; the support may be doped with one or more modifying elements such as phosphorus, silicon, boron, fluorine, and sodium. The content of the modifying element is less than 6% of the support mass, preferably 0.5%-6.0% of the support mass.

[0013] A second aspect of this invention provides a method for preparing an Ag-modified hydrogenation catalyst, the method comprising:

[0014] (1) The oxidized hydrogenation catalyst is subjected to primary sulfidation to obtain the sulfidized hydrogenation catalyst;

[0015] (2) The sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment;

[0016] (3) Pass an organic solution containing Ag into the catalyst treated in step (2) to carry out the reaction and obtain a hydrogenation catalyst containing Ag.

[0017] (4) The catalyst obtained in step (3) is subjected to secondary sulfidation to obtain Ag-modified hydrogenation catalyst.

[0018] 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%.

[0019] 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.

[0020] 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.

[0021] Further, in step (1), the initial sulfidation is a full sulfidation, meaning the active metal in the oxidized hydrogenation catalyst reaches complete sulfidation. A sulfidation method known in the art can be used. For example, the conditions for the initial sulfidation are as follows: sulfidation temperature of 240-400℃, preferably 300-380℃; sulfidation time of 3-8h; during sulfidation, hydrogen pressure of 2.0-12.0 MPa, preferably 3.0-8.0 MPa; and hydrogen flow rate of 2.0-15.0 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 3.0-15.0 mL·min -1 ·g -1 Oxidized hydrogenation catalyst.

[0022] Further, in step (1), the vulcanizing liquid used for the initial vulcanization 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 vulcanizing liquid is 2%-6%, preferably 4%-6%. The flow rate of the vulcanizing 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.

[0023] Furthermore, in step (2), the desulfurization treatment is a mild desulfurization treatment, carried out in at least one of the following ways:

[0024] (a) The sulfided hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment using hydrogen gas containing hydrogen sulfide;

[0025] (b) In the presence of hydrogen, the sulfurized hydrogenation catalyst obtained in step (1) is subjected to desulfurization treatment with a sulfurized liquid.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] Further, in step (4), the secondary vulcanization can be wet vulcanization, and the vulcanizing liquid used in the secondary vulcanization includes sulfur-containing compounds and organic solvents; the mass fraction of sulfur-containing compounds in the vulcanizing liquid is 1.0%-5.0%, preferably 1.5%-3.5%. The sulfur compounds are one or more of diethyl sulfide, ethanethiol, n-butanethiol, di-tert-aminobenzyl polysulfide, and dimethyl sulfoxide, and the organic solvents are one or more of cyclohexane, n-heptane, aviation kerosene, and diesel oil.

[0032] Further, in step (4), the conditions for the secondary vulcanization are as follows: temperature is 250-350℃, preferably 280-320℃; time is 2.0-24.0h, preferably 4.0-16.0h; hydrogen pressure is 2.0-8.0MPa, preferably 2.0-6.0MPa; and hydrogen flow rate is 2-15mL·min. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 5-10 mL·min -1 ·g -1 Oxidized hydrogenation catalyst. The flow rate of the sulfidation liquid is 1-5 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst, preferably 2-4 mL·h -1 ·g -1 Oxidized hydrogenation catalyst.

[0033] Furthermore, the temperature of the initial vulcanization is higher than that of the secondary vulcanization, preferably 20 to 100°C higher, and the temperature of the secondary vulcanization is higher than that of the desulfurization treatment, preferably 20 to 80°C higher.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] 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.

[0039] This invention first performs initial sulfidation and desulfurization on the oxidized hydrogenation catalyst, placing the metal active phase to be modified in a specific desulfurized, highly active state. The outer layer of the active phase edge is exposed active metal, while effectively preserving the tri-coordinated sulfur atoms and stable Ni-Mo-S crystal structure within the hydrogenation active phase. This allows the modified Ag element to more effectively contact the outer metal phase of the active phase. Ag, Ni, Mo, and S form an Ag-Ni-Mo-S composite mixed active phase. Then, a secondary sulfidation is performed to form a more stable structure between Ag and sulfur, coating the outside of the Ni-Mo-S active phase, making the sulfur in the active phase more stable. Detailed Implementation

[0040] 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.

[0041] In this invention, the Ag-modified hydrogenation catalyst was characterized by TEM-EDS (transmission electron microscopy-energy dispersive X-ray spectroscopy) using an instrument model JY / T011-1996, 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, and the Ag content distribution was statistically analyzed by EDS. 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.)

[0042] In this invention, the sulfur content at the corner sites of the Ni-Mo-S active phase relative to the total sulfur content of the Ni-Mo-S active phase is characterized using the TEM-EDS method. The instrument used is a JY / T011-1996, JEM-1400Flash. The determination process is as follows: The catalyst particles are ground and 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 less than 1nm away from the edge (which can be considered the corner site 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 of 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.

[0043] The oxidized hydrogenation catalysts used in the following embodiments and comparative examples of this invention were all prepared by the following methods:

[0044] 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 3Weigh 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%).

[0045] Example 1

[0046] Take 1000g of cyclohexane and 50.0g of dimethyl disulfide, and the resulting sulfidation solution is denoted as SQ-0.

[0047] Take 1000g of cyclohexane and 2.0g of dimethyl disulfide, and the resulting sulfidation solution is denoted as TQ-1.

[0048] Take 2000g of toluene and 70.0g of silver stearate, and prepare an organic solution containing silver, denoted as YQ-1.

[0049] Take 1000g of cyclohexane and 25.0g of dimethyl disulfide, and the resulting sulfidation solution is denoted as RQ-1.

[0050] Take 20.0g of CT-0 and put it into a reaction tube. Use SQ-0 for initial sulfidation under the following conditions: sulfidation temperature of 350℃, hydrogen pressure of 6.0MPa, hydrogen flow rate of 300.0mL / min, sulfidation liquid SQ-0 flow rate of 40.0mL / h, and sulfidation time of 6 hours. The resulting sulfided hydrogenation catalyst is denoted as SCT-0.

[0051] 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.

[0052] 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 YCT-1.

[0053] The reaction tube temperature was increased to 280℃, the hydrogen pressure was adjusted to 2.0 MPa, and the hydrogen flow rate was 120.0 mL / min. RQ-1 was introduced into the reaction tube at a flow rate of 40.0 mL / h, and the treatment time was 4.0 hours. The resulting catalyst was designated ECT-1.

[0054] Example 2

[0055] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0056] Take 1000g of cyclohexane and 3.0g of carbon disulfide to prepare a sulfidation liquid, which is denoted as TQ-2.

[0057] Take 2000g of toluene and 80.0g of silver acetylacetone, and prepare an organic solution containing silver, denoted as YQ-2.

[0058] Take 1000g of cyclohexane and 30.0g of carbon disulfide to prepare a sulfidation solution, which is denoted as RQ-2.

[0059] 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.

[0060] 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 YCT-2.

[0061] The reaction tube temperature was increased to 300℃, the hydrogen pressure was adjusted to 3.0 MPa, and the gas flow rate was 150.0 mL / min. RQ-2 was introduced into the reaction tube at a flow rate of 50.0 mL / h, and the treatment time was 5.0 hours. The resulting catalyst was designated ECT-2.

[0062] Example 3

[0063] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0064] Take 1000g of cyclohexane and 4.0g of dimethyl disulfide, and the resulting sulfidation solution is designated as TQ-3.

[0065] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate, and prepare an organic solution containing silver, denoted as YQ-3.

[0066] Take 1000g of cyclohexane and 35.0g of dimethyl disulfide, and the resulting sulfidation solution is designated as RQ-3.

[0067] 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.

[0068] 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 YCT-3.

[0069] The reaction tube temperature was increased to 320℃, the hydrogen pressure was adjusted to 3.5 MPa, and the hydrogen flow rate was 180.0 mL / min. RQ-3 was introduced into the reaction tube at a flow rate of 60.0 mL / h, and the treatment time was 6.0 hours. The obtained catalyst was designated ECT-3.

[0070] Example 4

[0071] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0072] Take 1000g of cyclohexane and 3.0g of di-tert-methyl polysulfide to prepare a sulfidation solution, which is designated as RQ-4.

[0073] Take 2000g of toluene and 100.0g of silver stearate to prepare an organic solution containing silver, denoted as YQ-4.

[0074] 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.

[0075] 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 YCT-4.

[0076] The reaction tube temperature was increased to 320℃, the hydrogen pressure was adjusted to 4.0 MPa, and the hydrogen flow rate was 200.0 mL / min. RQ-4 was introduced into the reaction tube at a flow rate of 60.0 mL / h, and the treatment time was 5.0 hours. The obtained catalyst was designated ECT-4.

[0077] Example 5

[0078] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0079] Take 1000g of cyclohexane and 3.0g of dimethyl sulfoxide, and the resulting sulfidation solution is designated as RQ-5.

[0080] Take 2000g of toluene and 60.0g of silver acetylacetone, and prepare an organic solution containing silver, denoted as YQ-5.

[0081] 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.

[0082] 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 for 12.0 hours. The resulting catalyst was designated YCT-5.

[0083] The reaction tube temperature was increased to 300℃, the hydrogen pressure was adjusted to 5.0 MPa, and the hydrogen flow rate was 200.0 mL / min. RQ-5 was introduced into the reaction tube at a flow rate of 60.0 mL / h, and the treatment time was 6.0 hours. The obtained catalyst was designated ECT-5.

[0084] Comparative Example 1

[0085] 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.

[0086] Comparative Example 2

[0087] The preparation process of catalyst DCT-1 is the same as that of comparative example 1.

[0088] 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.

[0089] Comparative Example 3

[0090] The preparation process of the sulfurized hydrogenation catalyst SCT-0 is the same as in Example 1.

[0091] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate, and prepare an organic solution containing silver, denoted as DYQ-3.

[0092] Take 1000g of cyclohexane and 35.0g of dimethyl disulfide, and the resulting sulfidation solution is designated as DRQ-3.

[0093] 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 DYCT-3.

[0094] The reaction tube temperature was increased to 320℃, the hydrogen pressure was adjusted to 3.5 MPa, and the hydrogen flow rate was 180.0 mL / min. DRQ-3 was introduced into the reaction tube at a flow rate of 60.0 mL / h, and the treatment time was 6.0 hours. The obtained catalyst was designated DCT-3.

[0095] Comparative Example 4

[0096] The preparation process of catalyst DCT-1 is the same as that of comparative example 1.

[0097] Take 2000g of toluene and 90.0g of silver cyclohexanebutyrate to prepare an organic solution containing silver, denoted as DYQ-4.

[0098] Take 1000g of cyclohexane and 35.0g of dimethyl disulfide to prepare a sulfidation solution, which is denoted as DRQ-4.

[0099] 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.

[0100] 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 DYCT-4.

[0101] The temperature of the reaction tube containing DYCT-4 was increased to 320℃, the hydrogen pressure was adjusted to 3.5 MPa, and the hydrogen flow rate was 180.0 mL / min. DRQ-4 was then introduced into the reaction tube at a flow rate of 60.0 mL / h for 6.0 hours. The resulting catalyst was designated DCT-4.

[0102] Comparative Example 5

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 20.0g of DCT-0 was loaded into a reaction tube and subjected to initial sulfidation 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 sulfidated hydrogenation catalyst was designated as DCT-5.

[0107] Table 1. Composition of the catalysts obtained in each example.

[0108] Catalyst number Mo, wt% Ni, wt% Ag, wt% S, wt% ECT-1 16.1 3.52 1.32 14.40 ECT-2 16.0 3.58 1.59 14.25 ECT-3 16.0 3.63 1.75 14.30 ECT-4 15.9 3.60 1.72 15.28 ECT-5 16.3 3.62 1.70 15.17 DCT-1 16.2 3.68 - 12.20 DCT-2 16.0 3.61 - 12.65 DCT-3 16.2 3.70 1.36 13.15 DCT-4 16.3 3.67 1.56 8.63 DCT-5 16.2 3.60 1.58 12.15

[0109] 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.

[0110] Table 2

[0111] 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 ,%]]> 91 88 87 89 92 - - 37 56 29 <![CDATA[S 边角位 / S 总 ,%]]> 2.7 2.9 2.7 2.7 2.8 7.3 1.8 8.9 5.5 7.4

[0112] Examples 6-10

[0113] The activity and stability of catalysts ECT-1 to ECT-5 were investigated in a fixed-bed hydrogenation unit under the following conditions: reaction pressure 6.0 MPa, hydrogen-to-oil volume ratio 400:1, temperature 280 °C, and volume hourly space velocity 1.5 h⁻¹. -1 Samples 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.

[0114] Comparative Examples 6-10

[0115] 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.

[0116] Table 3 Properties of Feed Oil

[0117]

[0118] Table 4 Catalyst Evaluation Results

[0119]

[0120]

[0121] 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. An Ag-modified hydrogenation catalyst, 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. The preparation method of the Ag-modified hydrogenation catalyst includes: (1) The oxidized hydrogenation catalyst is subjected to primary sulfidation to obtain the sulfidated hydrogenation catalyst, wherein the primary sulfidation is full sulfidation; (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 a hydrogenation catalyst containing Ag. (4) The catalyst obtained in step (3) is subjected to secondary sulfidation to obtain Ag-modified hydrogenation catalyst.

2. The Ag-modified hydrogenation catalyst according to claim 1, 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.

3. The Ag-modified hydrogenation catalyst according to claim 1, 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 refers to the sulfur content at the edge endpoint of the active phase, which is less than 1 nm away from the edge endpoint.

4. The Ag-modified hydrogenation catalyst according to claim 3, 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.

5. The Ag-modified hydrogenation catalyst according to claim 1, characterized in that: Based on the mass of the 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 the support is 50%-80%.

6. The Ag-modified hydrogenation catalyst according to claim 5, 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%.

7. A method for preparing the Ag-modified hydrogenation catalyst according to claim 1, comprising: (1) The oxidized hydrogenation catalyst is subjected to primary sulfidation to obtain the sulfidated hydrogenation catalyst, wherein the primary sulfidation is full sulfidation; (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 a hydrogenation catalyst containing Ag. (4) The catalyst obtained in step (3) is subjected to secondary sulfidation to obtain Ag-modified hydrogenation catalyst.

8. The method according to claim 7, 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%.

9. The method according to claim 7, characterized in that: In step (1), the initial vulcanization conditions are as follows: vulcanization temperature is 240-400℃, vulcanization time is 3-8h, and during vulcanization, 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.

10. The method according to claim 9, characterized in that: In step (1), the initial vulcanization conditions are as follows: the vulcanization temperature is 300-380℃, the hydrogen pressure during vulcanization is 3.0-8.0 MPa, and the hydrogen flow rate is 3.0-15.0 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

11. The method according to claim 7, 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.

12. The method according to claim 11, 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.

13. The method according to claim 12, 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.

14. The method according to claim 11, 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.

15. The method according to claim 14, 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.

16. The method according to claim 11, 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.

17. The method according to claim 16, 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.

18. The method according to claim 7, 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.

19. The method according to claim 18, 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.

20. The method according to claim 19, characterized in that: The flow rate of the organic solution containing Ag is 3-8 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst.

21. The method according to claim 7, 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, and hydrogen flow rate 2-20 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

22. The method according to claim 21, 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, and hydrogen flow rate 5-15 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst.

23. The method according to claim 7, characterized in that: In step (4), the secondary vulcanization is carried out using wet vulcanization. The vulcanizing liquid used includes sulfur-containing compounds and organic solvents. The mass fraction of sulfur-containing compounds in the vulcanizing liquid is 1.0%-5.0%. The conditions for the secondary vulcanization are as follows: temperature is 250-350℃, time is 2.0-24.0 h, hydrogen pressure is 2.0-8.0 MPa, and hydrogen flow rate is 2-15 mL·min. -1 ·g -1 An oxidized hydrogenation catalyst is used, and the flow rate of the sulfidation liquid is 1-5 mL·h. -1 ·g -1 Oxidized hydrogenation catalyst.

24. The method according to claim 23, characterized in that: In step (4), the mass fraction of sulfur compounds in the sulfidation liquid is 1.5%-3.5%; the conditions for the secondary sulfidation are as follows: temperature is 280-320℃, time is 4.0-16.0 h; hydrogen pressure is 3.0-6.0 MPa, and hydrogen flow rate is 5-10 mL·min. -1 ·g -1 Oxidized hydrogenation catalyst; the flow rate of the sulfidation liquid is 2-4 mL·h -1 ·g -1 Oxidized hydrogenation catalyst.

25. The method according to claim 7, 9, 12 or 23, characterized in that: The temperature of the initial vulcanization is higher than that of the secondary vulcanization, and the temperature of the secondary vulcanization is higher than that of the desulfurization treatment.

26. The method according to claim 25, characterized in that: The temperature of the initial vulcanization is 20-100℃ higher than that of the secondary vulcanization, and the temperature of the secondary vulcanization is 20-80℃ higher than that of the desulfurization treatment.

27. The use of an Ag-modified hydrogenation catalyst according to any one of claims 1-6 or an Ag-modified hydrogenation catalyst prepared according to any one of claims 7-26 in the hydrogenation of low-sulfur oil products.

Images