Novel hydrogenation catalyst and preparation method thereof

Abstract

A novel hydrogenation catalyst and a preparation method thereof belong to the technical field of catalysts. Comprising the following steps: 1) soaking sepiolite in deionized water, settling, and removing impurities to obtain a substance a; 2) uniformly mixing the substance a with metatitanic acid, adding a pore-enlarging agent, an adhesive and water, forming, drying and roasting to obtain a carrier b; 3) preparing a mixed solution of a cobalt salt and a nickel salt, adding a molybdenum salt, a complexing agent and a solvent to obtain an impregnation liquid c, impregnating the carrier b in the impregnation liquid c, drying, and roasting to obtain a mixture d; and 4) preparing an impregnation liquid e from nickel salt, ammonium hydrogen phosphate and a solvent, impregnating the mixture d in the impregnation liquid e, drying, and roasting. The active components of the prepared novel hydrogenation catalyst are distributed in multiple layers from the outside of the carrier to the inside of the carrier, the active component of the outermost layer of the core is nickel phosphide, the active metal components of the middle layer of the shell are nickel oxide and molybdenum oxide, and the core is molybdenum oxide and cobalt oxide. The novel hydrogenation catalyst provided by the invention can realize oxidation-state activation and has high low-temperature activity.

Description

Technical Field

[0001] The invention discloses a novel hydrogenation catalyst and a preparation method thereof, belonging to the technical field of catalysts. Background Art

[0002] The production and effective utilization of hydrogen energy is currently the research focus and hotspot of colleges and universities and social research institutions. In order to cater to the upcoming hydrogen energy era, it is urgent to develop modular hydrogen production equipment and its supporting catalysts. For modular hydrocarbon steam reforming hydrogen production equipment, due to its highly integrated reactor and more stringent process conditions, the process conditions and activity of existing industrial catalysts cannot meet the use requirements. Therefore, it is necessary to develop high-activity hydrogenation agents suitable for modular hydrogen production. The sulfur and chlorine in hydrocarbon hydrogen production raw materials must be removed to prevent poisoning of conversion and transformation catalysts. Cobalt-molybdenum catalysts are often used to remove organic sulfur and organic chlorine in hydrogen production raw materials to generate easily removable H2S and HCl, and the next step is fine desulfurization.

[0003] At present, the active components of commonly used hydrogenation catalysts are mostly composed of VIB group and / or VIII group metals, such as W, Mo, Co, Ni and other elements. These existing catalysts need to be pre-sulfurized before use, and the catalyst components are first converted from an oxidized state to a sulfurized state, and then activated in the sulfurized state. The reason why the above method has to be adopted is that in the existing technology, the activity and stability of the catalyst after sulfurization can be significantly improved, which is more convenient for application in industrial production.

[0004] Conventional presulfidation methods are divided into online in-vessel presulfidation and off-vessel presulfidation. In-vessel presulfidation is to load the oxidized catalyst into the reactor, and introduce hydrogen and sulfiding agent or hydrogen at a certain temperature to perform presulfidation, so that the active metal components of the catalyst are converted into a sulfided state. In-vessel presulfidation can be divided into dry presulfidation and wet presulfidation.

[0005] Ex-situ presulfurization technology can also be divided into two categories: one is the ex-situ presulfurization technology that uses sulfiding agents such as elemental sulfur, organic polysulfides, inorganic sulfides and hydrogen sulfide for loading. The other is a technology that, after the catalyst has been normally sulfided, is passivated or otherwise pretreated to improve the stability and initial activity of the sulfided catalyst and facilitate the storage and transportation of the catalyst. Among them, the presulfurization method for loading sulfur-containing compounds is easy to be lost with the gas during the heating process of the industrial device due to the variety of sulfides, resulting in a low degree of sulfidation, which affects its conversion activity and service life. With in-situ presulfurization, the modular hydrogen production device has no source of sulfur materials; with ex-situ presulfurization, there is a problem of sulfur release when the device is started due to the temperature increase, which poses a safety and environmental hazard.

[0006] Patent CN109722302A introduces a combined cracking desulfurization method and device and a combined process of catalytic cracking and adsorption desulfurization, and discloses the catalytic cracking catalyst and desulfurization catalyst used. This patent directly desulfurizes liquefied gas and gasoline and / or diesel without separation, and separates LPG and gasoline and / or diesel after desulfurization, thereby reducing separation costs. Although this patent uses sepiolite as a carrier and uses nickel, cobalt, and molybdenum elements in the catalyst, it cannot achieve oxidation state activation of the catalyst, and does not involve how to improve the low-temperature activity of the catalyst.

[0007] Patent CN112473697B introduces a nickel-cobalt-tungsten multi-sulfide catalyst with a core-shell spherical structure. The patent first disperses cobalt, nickel nitrate and glycerol in isopropanol, and reacts at 160°C in a hydrothermal autoclave for several hours to obtain a nickel-cobalt-glycerol precursor; then, ammonium tungstate and thioacetamide are dissolved in ethanol and mixed with the previously obtained nickel-cobalt-glycerol precursor, and after reacting in a hydrothermal autoclave for several hours, a Co9S8-Ni3S2@WS2 catalyst with a shell spherical structure is obtained after drying and calcination. The catalyst can be used in solar cells with different application fields, and does not involve how to activate the catalyst in its oxidation state.

[0008] Commonly used industrial catalysts need to be sulfurized to have high activity at 350°C, which brings great inconvenience in industrial production. In view of the process limitations of modular hydrogen production devices and the shortcomings of high-temperature activation of existing industrial catalysts, it is urgent to develop a hydrogenation catalyst that is suitable for modular devices and has high low-temperature activity and can be activated in the oxidation state. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a novel hydrogenation catalyst and a preparation method thereof. The prepared novel hydrogenation catalyst can be activated in an oxidized state and has high low temperature activity.

[0010] The technical solution of the method adopted by the present invention to solve the technical problem is: the preparation method of the novel hydrogenation catalyst is characterized by comprising the following steps: 1) Soak sepiolite in deionized water, settle, remove impurities, and obtain substance a; 2) Mix material a and metatitanic acid evenly, add pore expander, binder and water, and perform molding, drying and calcination to obtain carrier b; 3) preparing a mixed solution of cobalt salt and nickel salt, and adding molybdenum salt, complexing agent and solvent to obtain impregnation solution c, impregnating carrier b in impregnation solution c, and then drying and calcining to obtain mixture d; 4) Prepare an impregnation solution e with nickel salt, ammonium hydrogen phosphate salt and solvent, immerse the mixture d in the impregnation solution e, and then dry and calcine to obtain the product.

[0011] The mass ratio of the metatitanic acid in step 2) to the sepiolite in step 1) is 1:3-1:8.

[0012] Step 3) The concentration of the impregnation solution c and the porosity of the carrier b satisfy the following relationship: C = C1 / C2, A = C × ґ / Ԑ C1 is the mass concentration of cobalt ions in the impregnation solution c; C2 is the mass concentration of nickel ions in the impregnation solution c; ґ is the catalyst tortuosity factor; Ԑ is the porosity of carrier b; A is the impact factor; C is the mass concentration ratio of cobalt and nickel ions; The value range of C is 0.1-1; the value range of A is 0.1-5.9; The numerical range of ґ is 2-7.7; the numerical range of Ԑ is 1.3-1.62.

[0013] Preferably, the numerical range of C is 0.65-1; the numerical range of A is 2.5-4.5; the numerical range of ґ is 4.4-7.6; and the numerical range of Ԑ is 1.3-1.4.

[0014] Step 3) The preparation of the mixed solution of cobalt salt and nickel salt comprises the following steps: preparing the mixed solution of cobalt salt and nickel salt within the numerical range of C. C is the mass concentration ratio of cobalt and nickel ions, and the numerical range of C is 0.1-1.

[0015] Step 3) The mass ratio of the molybdenum salt, the cobalt salt and the nickel salt is: 1:0.67-1.2:1-1.2.

[0016] Step 3) The complexing agent is one or two of ammonia water, citric acid and phosphoric acid.

[0017] Step 3) The specific operation of the calcination is: heating to 180-250°C at a rate of 1-4°C / min, constant temperature calcination for 1-2h, then heating to 350-450°C at a rate of 1-4°C / min and constant temperature calcination for 2-3h.

[0018] Preferably, the specific operation of the calcination in step 3) is: heating to 200-250°C at a rate of 2-3°C / min and calcining at a constant temperature for 1.5-2h, then heating to 450°C at a rate of 2-3°C / min and calcining at a constant temperature for 2.5h.

[0019] In step 4), the mass ratio of the nickel salt to the ammonium hydrogen phosphate salt is 0.4-2.0: 1. Preferably, in step 4), the mass ratio of the nickel salt to the ammonium hydrogen phosphate salt is 0.5-1.9: 1.

[0020] Step 4) The specific operation of the calcination is: heating to 180-200°C at a rate of 1-4°C / min, constant temperature calcination for 1-2h, then heating to 400-500°C at a rate of 1-4°C / min and constant temperature calcination for 2-3h.

[0021] Preferably, the specific operation of step 4) of the calcination is: heating to 180-200°C at a rate of 2-3°C / min, constant temperature calcination for 2h, then heating to 450°C at a rate of 1-4°C / min and constant temperature calcination for 2.5h.

[0022] The novel hydrogenation catalyst prepared according to the preparation method has active components distributed in multiple layers from the outside of the carrier to the inside of the carrier, the outermost active component of the core is nickel phosphide, the active metal components of the middle layer of the shell are nickel oxide and molybdenum oxide, and the core is molybdenum oxide and cobalt oxide.

[0023] The catalyst contains 12.5-22% by mass of active components, wherein the active components are calculated as nickel phosphide, cobalt oxide, molybdenum oxide and nickel oxide, wherein the content of nickel phosphide accounts for 4-6% of the mass of the catalyst, the content of molybdenum oxide accounts for 6-10% of the mass of the catalyst, the content of cobalt oxide accounts for 1-3% of the mass of the catalyst, the content of nickel oxide accounts for 1.5-3% of the mass of the catalyst, and the remaining components of the catalyst are composite carriers.

[0024] The thickness of the outermost layer of the catalyst core is 0.2-0.5 mm, the thickness of the shell middle layer is 0.2-0.8 mm, and the thickness of the core layer is 0.5-1.3 mm.

[0025] The catalyst has a columnar shape and a clover-shaped or circular cross section with a diameter of 2.0 mm to 3.5 mm. The sum of the thickness of the outermost core layer, the middle shell layer and the core layer is ≤ the cross-sectional radius of the catalyst.

[0026] The present invention is described as follows: The soaking time in step 1) is 30-240 min, preferably, the soaking time in step 1) is 45-100 min.

[0027] Step 2) The mixing time is 20-180 min, preferably 30-60 min.

[0028] The soaking in step 1), the impregnation in step 3), and the impregnation in step 4) are all carried out at room temperature.

[0029] Step 2) The drying temperature is 90-110° C. Step 2) The specific operation of the calcination is: heating to 180-200° C. at a rate of 2-3° C. / min and calcining at a constant temperature for 1-1.5 hours, and then heating to 340-350° C. at a rate of 2-3° C. / min and calcining at a constant temperature for 4-4.5 hours.

[0030] Step 2) The binder is one or both of nitric acid and citric acid; Step 2) The pore expander is polyethylene glycol, starch or sucrose. Preferably, Step 2) The pore expander is polyethylene glycol, and the pore expander has both pore expansion and lubrication effects.

[0031] Step 2) The binder is one or both of nitric acid and citric acid; Step 2) The pore expander is polyethylene glycol, starch or sucrose. Preferably, Step 2) The pore expander is polyethylene glycol, and the pore expander has both pore expansion and lubrication effects.

[0032] Step 3) The drying temperature is 80-110°C. Step 4) The drying temperature is 80-110°C.

[0033] In step 3), the molybdenum salt is one of molybdenum nitrate, molybdenum acetate and molybdenum oxalate; in step 3), the cobalt salt is one of cobalt nitrate, cobalt acetate and cobalt oxalate; in step 3), the nickel salt is one of nickel nitrate, nickel acetate and nickel oxalate. In step 3), the solvent is water.

[0034] The nickel salt in step 4) is one of nickel nitrate, nickel acetate and nickel oxalate; the ammonium hydrogen phosphate in step 4) is diammonium hydrogen phosphate. Preferably, the nickel salt in step 4) is nickel nitrate. The solvent in step 4) is water.

[0035] The application of the novel hydrogenation catalyst of the present invention is in the field of sulfur-free low-temperature activation of hydrogenation raw material hydrogenation agents. Specifically, the novel hydrogenation catalyst of the present invention can be used in the case of light hydrocarbons as raw materials, reaction temperature of 200-400°C, hydrocarbon gas space velocity of 800-4000h －1 , under the condition of system pressure of 2.5-3.5MPa, it can be activated without sulfidation, and the organic sulfur in the raw materials can be removed to generate hydrogen sulfide. Light hydrocarbons are natural gas, synthesis gas, and refinery gas.

[0036] In the novel hydrogenation catalyst of the present invention, the active component nickel phosphide of the outermost layer of the core is prepared by step 4), while the shell middle layer and the core are prepared by step 3), but the active components of the shell middle layer and the core are different, the active metal components of the shell middle layer are nickel oxide and molybdenum oxide, and the core is molybdenum oxide and cobalt oxide. The applicant found in the study that when the prepared impregnation solution c satisfies the relationship C=C1 / C2, A=C×ґ / Ԑ (the numerical range of C is 0.1-1; the numerical range of A is 0.1-5.9), the carrier is impregnated with an active component impregnation solution of a suitable concentration under the above relationship conditions to effectively form a multi-layer active component distribution.

[0037] The novel hydrogenation catalyst of the present invention has different components and functions in the outermost layer of the core, the middle layer of the shell and the core layer, and the components and impregnation order of each layer cannot be replaced at will. The outermost layer of the core can promote the activation of the oxidation state and initiate the hydrogenation reaction. The sulfide produced by the reaction gradually diffuses into the interior of the catalyst, is gradually reduced through the middle layer of the shell and the core layer, and sulfides the oxidation state metal. The active components in the middle layer of the shell ensure the low temperature activity of the catalyst, and the active components in the core ensure the hydrogenation activity of the catalyst.

[0038] Step 2) The carrier b is a titanium dioxide-sepiolite composite carrier. Sepiolite is a magnesium-rich silicate clay mineral. Its theoretical chemical formula is Mg8[Si 12 O 30 ](OH)4·12H2O, 4 of the water molecules are crystal water: the rest are zeolite water. Sepiolite belongs to the chain-layered hydrous magnesium aluminum silicate or magnesium silicate mineral of S monoclinic or orthorhombic system. It has a huge specific surface area that can adsorb various reactants and active components of catalysts. Since sepiolite has alkaline and acidic centers, reactants are easily polarized into activated complexes at the center, producing synergistic catalytic effects with catalysts. Sepiolite has a fibrous structure, which can form a large specific surface area and inter-particle voids, has strong adsorption, and can provide more active sites. However, the mechanical strength of sepiolite is poor, and its strength as a catalyst carrier alone is insufficient, so it needs to be added with other carriers. The surface of titanium dioxide has suitable acidity, and the interaction with the active components is also weak, which improves the dispersion of the active components and the degree of reduction of the active phase. At the same time, there is a synergistic effect with the active components, playing the role of an electronic auxiliary agent, but titanium dioxide has the disadvantages of small specific surface area and poor thermal stability. In order to overcome these shortcomings, sepiolite-titanium dioxide is made into a composite carrier, and the high specific surface area and high thermal stability of sepiolite are used to overcome the defects of titanium dioxide itself, while maintaining the advantages of titanium dioxide in the hydrodesulfurization reaction.

[0039] Compared with the prior art, the present invention has the following beneficial effects: 1. The novel hydrogenation catalyst of the present invention can be activated in an oxidized state and has high low-temperature activity. The active metal components of the catalyst prepared by the present invention are distributed in multiple layers along the radial direction of the carrier, the active components of the outermost layer of the core are nickel phosphide, the active metal components of the middle layer of the shell are nickel oxide and molybdenum oxide, and the core is molybdenum oxide and cobalt oxide. The multi-layer structure is adopted, and the outermost layer of the core provides the initial activity of the catalyst to promote the hydrogenation reaction. At the same time, the sulfide generated gradually diffuses into the interior of the catalyst to sulfide the oxidized metal, thereby improving the activity of the catalyst, so that the hydrogenation catalyst of the modular hydrogen production device can be activated in an oxidized state and at a low temperature, so as to achieve the purpose of environmental protection and energy saving.

[0040] The acidic and alkaline centers of sepiolite in the titanium dioxide-sepiolite composite carrier convert the adsorbed organic matter into an activated complex, and titanium dioxide enters the sepiolite fiber rod layer structure, making the catalyst structure stable, the acidity enhanced, the active sites increased, and the catalyst reaction activity improved. The composite carrier is conducive to the dispersion of active components, making the active components easier to be reduced, and weakening the interaction between the carrier and the metal oxide, making it easier for the metal oxide to form active component sulfide in the presence of hydrogen sulfide.

[0041] 2. The novel hydrogenation catalyst of the present invention does not release sulfur during use and is environmentally friendly. When the novel hydrogenation catalyst prepared by the present invention is used in industry, it can realize the low-temperature activation of hydrogenation raw material hydrogenation agent without sulfurization. No sulfur is released during the process, it is environmentally friendly, and has good economic benefits and application prospects. The novel hydrogenation catalyst of the present invention can be used with natural gas, synthesis gas, refinery gas and other light hydrocarbons as raw materials. When used in the process, the reaction temperature is 200-400℃ and the hydrocarbon gas space velocity is 800-4000h －1 Under the system pressure of 2.5-3.5MPa, the catalyst can be directly activated in the oxidized state of the feed at 200℃, removing the organic sulfur in the raw material to generate hydrogen sulfide. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of the structure of the catalyst obtained in Example 1.

[0043] Figure 2 It is a schematic diagram of the process flow of a small-scale hydrogenation evaluation device for performance testing.

[0044] Among them: 101, the outermost layer of the core; 102, the middle layer of the shell; 103, the core; D, the cross-sectional diameter of the catalyst; x, the thickness of the outermost layer; y, the thickness of the middle layer of the shell; z, the thickness of the core; 1, mass flow meter; 2, stop valve; 3, preheater; 4, reactor; 5, separator; 6, vaporization chamber; 7, flow valve; 8, chromatograph; 9, pressure gauge. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with specific examples, wherein Example 1 is the best example. The comparative examples are designed to compare the effects of the examples.

[0046] Reference Figure 1, a novel hydrogenation catalyst, the active components of the catalyst are distributed in multiple layers from the outside of the carrier to the inside of the carrier, the active components of the outermost layer 101 of the core are nickel phosphide, the active metal components of the shell middle layer 102 are nickel oxide and molybdenum oxide, and the core 103 is molybdenum oxide and cobalt oxide. The thickness x of the outermost layer 101 of the catalyst core is 0.2-0.5mm, the thickness y of the shell middle layer 102 is 0.2-0.8mm, and the thickness z of the core 103 is 0.5-1.3mm. The appearance of the catalyst is columnar, and the catalyst cross-sectional diameter D is clover-shaped or circular with a diameter of 2.0mm-3.5mm. In order to reduce variables, the catalyst used in the embodiments and comparative examples is a columnar catalyst with a circular cross-section, and the catalyst cross-sectional diameter D is 3.5mm.

[0047] Example 1 The preparation method of the novel hydrogenation catalyst of this embodiment comprises the following steps: 1) Take 64.3 g of sepiolite and soak it in deionized water, let it settle, remove impurities, and obtain substance a; 2) Material a was mixed evenly with 26.3 g of metatitanic acid, and 3 g of polyethylene glycol, 3 g of citric acid, 3 g of nitric acid and 57 g of water were added. The mixture was formed, dried at 90°C, and heated to 200°C at a rate of 2°C / min and calcined at a constant temperature for 1 h. The mixture was then heated to 350°C at a rate of 2°C / min and calcined at a constant temperature for 4.5 h to obtain carrier b. 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 0.65, and adding 8.4 g of molybdenum nitrate, 4.53 g of citric acid and 50 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1 hour, then drying at 90°C, then heating to 200°C at a rate of 2°C / min and calcining at a constant temperature for 1.5 hours, then heating to 450°C at a rate of 2°C / min and calcining at a constant temperature for 2.5 hours, to obtain a mixture d; 4) 17.9 g of nickel nitrate, 15.86 g of ammonium hydrogen phosphate and water are used to prepare an impregnation solution e. The mixture d is immersed in the impregnation solution e for 1 hour, and then dried at 90°C. The mixture is heated to 180°C at a rate of 3°C / min and calcined at a constant temperature for 2 hours. The mixture is then heated to 450°C at a rate of 3°C / min and calcined at a constant temperature for 2.5 hours to obtain a catalyst. The catalyst is labeled A.

[0048] Example 2 The preparation method of the novel hydrogenation catalyst of this embodiment comprises the following steps: 1) Take 53.8 g of sepiolite and soak it in deionized water, let it settle, remove impurities, and obtain substance a; 2) Material a was mixed evenly with 22.0 g of metatitanic acid, and 3 g of starch, 3 g of citric acid, 3 g of nitric acid and 53 g of water were added, and the mixture was formed, dried at 110°C, and heated to 180°C at a rate of 3°C / min and calcined at a constant temperature for 1.5 h, and then heated to 340°C at a rate of 3°C / min and calcined at a constant temperature for 4.5 h to obtain carrier b; 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 1, and adding 15.7 g of molybdenum nitrate, 8.46 g of citric acid and 52 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1.5 hours, then drying at 80°C, then heating to 250°C at a rate of 3°C / min and calcining at a constant temperature for 2 hours, then heating to 450°C at a rate of 3°C / min and calcining at a constant temperature for 3 hours, to obtain a mixture d; 4) Prepare impregnation solution e with 30.2 g nickel nitrate, 29.1 g ammonium hydrogen phosphate and water, immerse the mixture d in the impregnation solution e for 1 hour, dry it at 80°C, heat it to 180°C at a rate of 3°C / min and calcine it at a constant temperature for 2 hours, then heat it to 450°C at a rate of 3°C / min and calcine it at a constant temperature for 2.5 hours to obtain a catalyst; label the catalyst B.

[0049] Example 3 The preparation method of the novel hydrogenation catalyst of this embodiment comprises the following steps: 1) Take 61.8 g of sepiolite and soak it in deionized water, let it settle, remove impurities, and obtain substance a; 2) Material a was mixed evenly with 19.0 g of metatitanic acid, and 4 g of sucrose, 3 g of citric acid, 3 g of nitric acid and 55 g of water were added. The mixture was formed, dried at 100°C, and heated to 190°C at a rate of 2°C / min and calcined at a constant temperature for 1.5 h. The mixture was then heated to 350°C at a rate of 3°C / min and calcined at a constant temperature for 4 h to obtain carrier b. 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 0.83, and adding 13.5 g of molybdenum nitrate, 7.28 g of citric acid and 52 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1.5 hours, then drying at 100° C., then heating to 250° C. at a rate of 3° C. / min and calcining at a constant temperature for 2 hours, then heating to 450° C. at a rate of 3° C. / min and calcining at a constant temperature for 3 hours, to obtain a mixture d; 4) Prepare impregnation solution e with 24.1 g nickel nitrate, 21.9 g ammonium hydrogen phosphate and water, immerse the mixture d in the impregnation solution e for 1 hour, dry it at 100°C, heat it to 200°C at a rate of 2°C / min and calcine it at a constant temperature for 2 hours, then heat it to 450°C at a rate of 2°C / min and calcine it at a constant temperature for 2.5 hours to obtain a catalyst; label the catalyst C.

[0050] Comparative Example 1 The difference between this comparative example and the embodiment is that the C value in step 3) is greater than that in the embodiment.

[0051] The preparation method of the catalyst of this comparative example comprises the following steps: 1) Take 61.8 g of sepiolite and soak it in deionized water, let it settle, remove impurities, and obtain substance a; 2) Material a was mixed evenly with 19.0 g of metatitanic acid, and 3 g of starch, 3 g of citric acid, 3 g of nitric acid and 55 g of water were added. The mixture was formed, dried at 100°C, and heated to 190°C at a rate of 2°C / min and calcined at a constant temperature for 1.5 h. The mixture was then heated to 350°C at a rate of 3°C / min and calcined at a constant temperature for 4 h to obtain carrier b. 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 1.2, and adding 13.5 g of molybdenum nitrate, 7.28 g of phosphoric acid and 52 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1.5 hours, then drying, and then heating to 250° C. at a rate of 3° C. / min and calcining at a constant temperature for 2 hours, and then heating to 450° C. at a rate of 3° C. / min and calcining at a constant temperature for 3 hours to obtain a mixture d; 4) Prepare impregnation solution e with 24.1 g nickel nitrate, 21.9 g ammonium hydrogen phosphate and water, immerse the mixture d in the impregnation solution e for 1 hour, dry it, heat it to 200°C at a rate of 2°C / min and calcine it at a constant temperature for 2 hours, then heat it to 450°C at a rate of 2°C / min and calcine it at a constant temperature for 2.5 hours to obtain a catalyst; label the catalyst D.

[0052] Comparative Example 2 The difference between this comparative example and the embodiment is that the components of carrier b are mainly changed.

[0053] The preparation method of the catalyst of this comparative example comprises the following steps: 1) 77.3 g of sepiolite was soaked in deionized water, allowed to settle, and impurities removed to obtain substance a; 2) Add 3g polyethylene glycol, 3g citric acid, 3g nitric acid and 55g water to substance a, form, dry at 90°C, heat to 200°C at a rate of 2°C / min and calcine at a constant temperature for 1h, then heat to 350°C at a rate of 2°C / min and calcine at a constant temperature for 4.5h to obtain carrier b; 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 0.83, and adding 13.5 g of molybdenum nitrate, 7.28 g of citric acid and 52 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1.5 hours, then drying at 90°C, and then heating to 250°C at a rate of 3°C / min and calcining at a constant temperature for 2 hours, and then heating to 450°C at a rate of 3°C / min and calcining at a constant temperature for 3 hours to obtain a mixture d; 4) Prepare impregnation solution e with 24.1 g nickel nitrate, 21.9 g ammonium hydrogen phosphate and water, immerse the mixture d in the impregnation solution e for 1 hour, dry at 90°C, heat to 200°C at a rate of 2°C / min and calcine at this temperature for 2 hours, then heat to 450°C at a rate of 2°C / min and calcine at this temperature for 2.5 hours to obtain a catalyst; label the catalyst E.

[0054] Comparative Example 3 The preparation method of the catalyst of this comparative example comprises the following steps: 1) Take 53.3 g of sepiolite and soak it in deionized water, let it settle, remove impurities, and obtain substance a; 2) Material a was mixed evenly with 13.3 g of metatitanic acid, and 3 g of starch, 3 g of citric acid, 3 g of nitric acid and 45 g of water were added, the mixture was formed, dried at 90°C, heated to 200°C at a rate of 2°C / min and calcined at a constant temperature for 1 h, and then heated to 350°C at a rate of 2°C / min and calcined at a constant temperature for 4.5 h to obtain carrier b; 3) preparing a mixed aqueous solution of cobalt nitrate and nickel nitrate meeting the C value of 1, and adding 18.0 g of molybdenum nitrate, 9.71 g of citric acid and 52 g of water to obtain an impregnation solution c, impregnating the carrier b in the impregnation solution c for 1.5 hours, then drying at 90° C., then heating to 250° C. at a rate of 3° C. / min and calcining at a constant temperature for 2 hours, then heating to 450° C. at a rate of 3° C. / min and calcining at a constant temperature for 3 hours, to obtain a mixture d; 4) 14.9 g of nickel nitrate, 13.5 g of ammonium hydrogen phosphate and water are used to prepare an impregnation solution e. The mixture d is immersed in the impregnation solution e for 1 hour, and then dried at 90°C. The mixture is heated to 180°C at a rate of 3°C / min and calcined at a constant temperature for 2 hours. The mixture is then heated to 450°C at a rate of 3°C / min and calcined at a constant temperature for 2.5 hours to obtain a catalyst. The catalyst is labeled F.

[0055] In the embodiments and comparative examples, the concentration of the impregnation solution c in step 3) and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C×ґ / Ԑ; C1 is the mass concentration of cobalt ions in the impregnation solution c; C2 is the mass concentration of nickel ions in the impregnation solution c; ґ is the catalyst tortuosity factor; Ԑ is the porosity of the carrier b; A is the influencing factor; C is the mass concentration ratio of cobalt and nickel ions; the values ​​of C, A, ґ, and Ԑ are detailed in Table 1.

[0056] Table 1 Catalyst composition .

[0057] Performance Testing use Figure 1 The small-scale pressurized evaluation device and evaluation conditions shown in the figure are used to test the hydrocarbon steam reforming catalysts prepared in the above examples and comparative examples. Figure 1 in reactor 4.

[0058] Test 1: Catalysts AF obtained in Example and Comparative Example were heated to 3.0 MPa at a carbon space velocity of 3000 h -1 , feed temperature 200℃, then raise the temperature, and carry out hydrogenation evaluation under the condition of bed temperature 250℃, the reaction raw material is 200ppm thiophene prepared by 6# solvent oil, the catalyst is loaded with 10ml, and the operation is 100h. The catalyst conversion rate formula is as follows, and the evaluation results are shown in the following table: Catalyst conversion rate formula = (initial concentration - equilibrium concentration) / initial concentration.

[0059] Table 2 Performance test results .

[0060] It can be seen from Table 2 that the 250°C thiophene conversion rate of Examples 1-3 is significantly higher than that of Comparative Examples 1-3, and the 250°C thiophene conversion rate is high, which proves that the present invention can achieve direct activation of the catalyst in the feed oxidation state of 200°C, high low-temperature activity, and high conversion rate.

[0061] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a novel hydrogenation catalyst, characterized in that: The steps include: 1) Soak sepiolite in deionized water, settle, remove impurities, and obtain substance a; 2) Mix material a and metatitanic acid evenly, add pore expander, binder and water, and perform molding, drying and calcination to obtain carrier b; 3) preparing a mixed solution of cobalt salt and nickel salt, and adding molybdenum salt, complexing agent and solvent to obtain impregnation solution c, impregnating carrier b in impregnation solution c, and then drying and calcining to obtain mixture d; 4) Prepare an impregnation solution e with nickel salt, ammonium hydrogen phosphate salt and solvent, immerse the mixture d in the impregnation solution e, and then dry and calcine to obtain the product.

2. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: The mass ratio of the metatitanic acid in step 2) to the sepiolite in step 1) is 1:3-1:

8.

3. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 3) The concentration of the impregnation solution c and the porosity of the carrier b satisfy the following relationship: C = C1 / C2, A = C × ґ / Ԑ C1 is the mass concentration of cobalt ions in the impregnation solution c; C2 is the mass concentration of nickel ions in the impregnation solution c; ґ is the catalyst tortuosity factor; Ԑ is the porosity of carrier b; A is the impact factor; C is the mass concentration ratio of cobalt and nickel ions; The value range of C is 0.1-1; the value range of A is 0.1-5.9; The numerical range of ґ is 2-7.7; the numerical range of Ԑ is 1.3-1.

62.

4. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 3) The mass ratio of the molybdenum salt, the cobalt salt and the nickel salt is: 1:0.67-1.2:1-1.

2.

5. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 3) The complexing agent is one or two of ammonia water, citric acid and phosphoric acid.

6. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 3) The specific operation of the calcination is: heating to 180-250°C at a rate of 1-4°C / min, constant temperature calcination for 1-2h, then heating to 350-450°C at a rate of 1-4°C / min and constant temperature calcination for 2-3h.

7. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 4) The mass ratio of the nickel salt to the ammonium hydrogen phosphate salt is 0.4-2.0:

1.

8. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: Step 4) The specific operation of the calcination is: heating to 180-200°C at a rate of 1-4°C / min, constant temperature calcination for 1-2h, then heating to 400-500°C at a rate of 1-4°C / min and constant temperature calcination for 2-3h.

9. The novel hydrogenation catalyst prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The active components of the catalyst are distributed in multiple layers from the outside of the carrier to the inside of the carrier. The active components of the outermost layer of the core are nickel phosphide, the active metal components of the middle layer of the shell are nickel oxide and molybdenum oxide, and the core is molybdenum oxide and cobalt oxide.

10. The method for preparing a novel hydrogenation catalyst according to claim 1, characterized in that: The catalyst contains 12.5-22% by mass of active components, where the active components are calculated as nickel phosphide, cobalt oxide, molybdenum oxide and nickel oxide, wherein the content of nickel phosphide accounts for 4-6% of the mass of the catalyst, the content of molybdenum oxide accounts for 6-10% of the mass of the catalyst, the content of cobalt oxide accounts for 1-3% of the mass of the catalyst, the content of nickel oxide accounts for 1.5-3% of the mass of the catalyst, and the remaining components of the catalyst are composite carriers.

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