Transition metal supported catalytic hydroisomerization catalyst as well as preparation method and application thereof

Abstract

The invention discloses a transition metal supported catalytic hydroisomerization catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysis. According to the technical scheme, the preparation method comprises the following steps: preparing nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ferric nitrate nonahydrate, aluminum nitrate nonahydrate, phosphoric acid and citric acid into a solution A; adding tetraethoxysilane into absolute ethyl alcohol to prepare a solution B; transferring the solution A and the solution B into a high-pressure reaction kettle, and fully reacting at 150-250 DEG C to obtain a catalyst precursor; calcining the catalyst precursor at 550-650 DEG C, and performing hydrogen reduction on the catalyst obtained after calcining to obtain the transition metal supported catalytic hydroisomerization catalyst. The preparation method is applied to the catalytic preparation of biological aviation kerosene, solves the technical problems of complex preparation process and poor activity and selectivity of the prepared catalyst in the existing hydroisomerization catalyst, and has the characteristics of simple preparation process and high activity and selectivity of the catalyst.

Description

Technical Field

[0001] The present invention belongs to the field of catalytic technology, and particularly relates to a transition metal-supported catalytic hydroisomerization catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] At present, the production processes of bio-aviation fuel mainly include the hydrotreating of oils and fats, the Fischer-Tropsch synthesis, the hydrothermal treatment of oils and fats, the bio-alcohol method, etc. Among them, the hydrotreating of oils and fats has a simpler process flow and higher product quality compared with other processes, and is the most competitive and commercially mature method. The process steps of the hydrotreating of oils and fats are as follows: using waste oils and fats as raw materials, removing impurities therein through pretreatment (including pickling, adsorption, etc.), then removing elements such as oxygen, nitrogen, and sulfur in the oils and fats through hydrodeoxygenation to prepare hydrogenated vegetable oil (HVO), and then adjusting the molecular structure by hydroisomerization of long-chain n-alkanes to meet the requirements of the low-temperature fluidity of aviation fuel (such as the freezing point ≤ -40 °C, etc.), and finally obtaining the bio-aviation fuel product through rectification and purification. In the prior art, noble metal catalysts (such as Pt, Pd) have high costs, low isomerization selectivity, and many cracking side reactions, resulting in insufficient product yields; while non-noble metal catalysts have low costs, but have problems such as insufficient active sites and difficult acid regulation.

[0003] Chinese Patent CN119237005A discloses a hydrocarbon skeletal isomerization catalyst, a preparation method thereof, and an application thereof, and specifically discloses the following steps: 1) contacting an active metal source solution with mesoporous silica or an anionic polymer to obtain a metal source; 2) mixing the metal source with a SAPO-11 synthesis system, and subjecting the obtained mixed system to crystallization treatment, drying treatment, and calcination treatment in sequence to obtain the catalyst; the SAPO-11 synthesis system includes deionized water, a phosphorus source, an aluminum source, a silicon source, and a structure-directing agent.

[0004] However, the above catalyst preparation process flow is complex, and it is necessary to first prepare a precursor, then mix the precursor with a silicon source, and the precursor uses a preformed carrier and then participates in the synthesis system of the carrier, and the distribution is not uniform enough. At the same time, the active component is a single component, and the selectivity and stability of the catalyst are poor. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the present invention solves the technical problems of the complex preparation process of the existing hydroisomerization catalyst and the poor activity and selectivity of the prepared catalyst, and provides a transition metal-supported catalytic hydroisomerization catalyst with a simple preparation process, high activity and selectivity of the catalyst, a preparation method thereof, and an application thereof.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a preparation method of a transition metal-supported catalytic hydroisomerization catalyst, including: Prepare solution A by mixing nickel nitrate hexahydrate, cobalt nitrate hexahydrate, iron nitrate nonahydrate, aluminum nitrate nonahydrate, phosphoric acid, and citric acid; Prepare solution B by adding tetraethyl orthosilicate to absolute ethanol; Transfer solution A and solution B to an autoclave and react them fully at 150 - 250 °C to obtain a catalyst precursor; Calcine the catalyst precursor at 550 - 650 °C and then reduce the obtained catalyst with hydrogen to obtain a transition metal - supported catalytic hydroisomerization catalyst.

[0007] By weight, the amount of nickel nitrate hexahydrate is any value in the range of 8 - 20 parts, the amount of cobalt nitrate hexahydrate is any value in the range of 3 - 10 parts, the amount of iron nitrate nonahydrate is any value in the range of 5 - 16 parts, the amount of aluminum nitrate nonahydrate is any value in the range of 40 - 100 parts, the amount of phosphoric acid is any value in the range of 5 - 20 parts, the amount of citric acid is any value in the range of 5 - 20 parts, and the amount of tetraethyl orthosilicate is any value in the range of 10 - 40 parts.

[0008] Preferably, ultrasonic - treat solution A and solution B and then transfer them to the autoclave.

[0009] Preferably, transfer solution A and solution B to an autoclave and react them at 150 - 250 °C for 6 - 24 hours to obtain a catalyst precursor, and then extrude the catalyst precursor into a certain shape; Calcine the extruded catalyst precursor at 550 - 650 °C for 2 - 8 hours and then reduce the obtained catalyst with hydrogen to obtain a transition metal - supported catalytic hydroisomerization catalyst.

[0010] On the other hand, the present invention provides a transition metal - supported catalytic hydroisomerization catalyst prepared by the preparation method of the transition metal - supported catalytic hydroisomerization catalyst described in any of the above - mentioned technical solutions.

[0011] Preferably, in the transition metal - supported catalytic hydroisomerization catalyst, the ICP content of nickel is 7 - 15%, the ICP content of cobalt is 2 - 8%, the ICP content of iron is 3 - 9%, the ICP content of aluminum is 12 - 30%, and the ICP content of silicon is 4 - 25%; The specific surface area of the transition metal - supported catalytic hydroisomerization catalyst is 211 - 235 m 2 / g.

[0012] The present invention also provides the application of the above - mentioned transition metal - supported catalytic hydroisomerization catalyst in hydroisomerization catalytic reactions.

[0013] Preferably, using n-octadecane as a raw material, a hydroisomerization catalytic reaction is carried out on it to prepare sustainable aviation fuel (SAF); including: loading a transition metal-supported hydroisomerization catalyst into a fixed-bed reaction tube, heating up for catalyst reduction, adjusting the reaction temperature after the catalyst reduction is completed, and continuously reacting by introducing hydrogen and HVO (hydrogenated vegetable oil) to obtain SAF (sustainable aviation fuel); The product yield is 93-97%, and the conversion rate of C18 is 99.15-99.61%; In the sustainable aviation fuel, the proportion of C5-C18 normal alkanes is 26.41-28.79%, and the proportion of C5-C18 isoalkanes is 71.21-73.59%.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a preparation method of a transition metal-supported hydroisomerization catalyst. By a hydrothermal method, a supported catalyst of multiple transition metals is prepared in one step. The multiple transition metals increase the synergistic effect of the catalyst active components, improve the catalyst activity and selectivity, and complete the carrier shaping and active component loading in one step, increasing the interaction between the active component and the carrier, and simplifying the process flow. Detailed Description of the Invention

[0015] The technical solutions in the specific embodiments of the present invention will be described in detail and completely below. Obviously, the described embodiments are only partial specific embodiments of the general technical solution of the present invention, rather than all embodiments. Based on the general concept of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.

[0016] On the one hand, the present invention provides a preparation method of a transition metal-supported hydroisomerization catalyst, including: preparing a solution A by mixing nickel nitrate hexahydrate, cobalt nitrate hexahydrate, iron nitrate nonahydrate, aluminum nitrate nonahydrate, phosphoric acid, and citric acid; preparing a solution B by adding tetraethyl orthosilicate to absolute ethanol; transferring the solution A and the solution B to a high-pressure reaction kettle, fully reacting at 150-250°C to obtain a catalyst precursor; calcining the catalyst precursor at 550-650°C, and reducing the obtained catalyst with hydrogen to obtain a transition metal-supported hydroisomerization catalyst.

[0017] The above preparation method of the present invention prepares a supported catalyst of multiple transition metals in one step by a hydrothermal method. The process flow is simple. The multiple transition metals increase the synergistic effect of the catalyst active components. The catalyst has a larger specific surface area and more active sites, improving the catalyst activity and selectivity. And the carrier shaping and active component loading are completed in one step, increasing the interaction between the active component and the carrier, and simplifying the process flow. At the same time, the above preparation method does not use precious metals as raw materials, effectively reducing the cost.

[0018] It should be emphasized that in the preparation process of the catalyst of the present invention, the preparation of the carrier and the loading of the active component are completed in one-step reaction. While simplifying the technological process and shortening the reaction steps, it can increase the dispersion degree of the active component in the carrier, increase the number of reaction sites, and enhance the stability of the catalyst.

[0019] In the above technical solution, by weight, the dosage of nickel nitrate hexahydrate is any value within 8 - 20 parts, the dosage of cobalt nitrate hexahydrate is any value within 3 - 10 parts, the dosage of iron nitrate nonahydrate is any value within 5 - 16 parts, the dosage of aluminum nitrate nonahydrate is any value within 40 - 100 parts, the dosage of phosphoric acid is any value within 5 - 20 parts, the dosage of citric acid is any value within 5 - 20 parts, and the dosage of tetraethyl orthosilicate is any value within 10 - 40 parts.

[0020] It can be understood that the dosage of nickel nitrate hexahydrate can also be 10, 12, 14, 16, 18 parts and any point value within its range, the dosage of cobalt nitrate hexahydrate can also be 4, 5, 6, 7, 8, 9 parts and any point value within its range, the dosage of iron nitrate nonahydrate can also be 7, 9, 11, 13, 15 parts and any point value within its range, the dosage of aluminum nitrate nonahydrate can also be 50, 60, 70, 80, 90 parts and any point value within its range, the dosage of phosphoric acid can also be 7, 9, 11, 13, 15, 17 parts and any point value within its range, the dosage of citric acid can also be 7, 9, 11, 13, 15, 17 parts and any point value within its range, and the dosage of tetraethyl orthosilicate can also be 15, 20, 25, 30, 35 parts and any point value within its range.

[0021] In the above technical solution, the nickel precursor salt is nickel nitrate hexahydrate, the cobalt precursor salt is cobalt nitrate hexahydrate, the iron precursor salt is iron nitrate nonahydrate, the aluminum precursor salt is aluminum nitrate nonahydrate, and the silicon precursor is tetraethyl orthosilicate. This technical solution specifically defines the types of the nickel precursor salt, cobalt precursor salt, iron precursor salt, aluminum precursor salt, and silicon precursor. Among them, the nickel precursor salt, cobalt precursor salt, and iron precursor salt are common and easily obtainable low-cost transition metals, and at the same time are common catalyst active component precursors for catalyzing isomerization, while the aluminum precursor salt and silicon precursor are common and easily obtainable low-cost aluminum and silicon molecular sieve precursors. In a preferred embodiment, solution A and solution B are subjected to ultrasonic treatment and then transferred to a high-pressure reaction kettle. Ultrasonic dispersion is beneficial to achieving the full dissolution of solution A and solution B and ensuring the uniformity of the solution.

[0022] In a preferred embodiment, solution A and solution B are transferred to a high-pressure reaction kettle and reacted at 150 - 250 °C for 6 - 24 hours to obtain a catalyst precursor, and then the catalyst precursor is extruded into a shape; The catalyst precursor after extrusion molding is calcined at 550 - 650 °C for 2 - 8 hours, and the obtained catalyst after calcination is reduced with hydrogen to obtain a transition metal-supported catalytic hydroisomerization catalyst.

[0023] It can be understood that the reaction temperature in the high-pressure autoclave can also be 180 °C, 200 °C, 220 °C, and any point value within this range, and the reaction time can also be 10 hours, 15 hours, 20 hours, and any point value within this range; the calcination temperature can also be 570 °C, 590 °C, 610 °C, 630 °C, and any point value within this range, and the calcination time can also be 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, and any point value within this range. The above hydrogen reduction step can be carried out in a fixed bed during the application of the catalyst.

[0024] On the other hand, the present invention provides a transition metal-supported catalytic hydroisomerization catalyst prepared by the preparation method of the transition metal-supported catalytic hydroisomerization catalyst described in any of the above technical solutions.

[0025] In a preferred embodiment, the ICP content of nickel in the transition metal-supported catalytic hydroisomerization catalyst is 7 - 15%, the ICP content of cobalt is 2 - 8%, the ICP content of iron is 3 - 9%, the ICP content of aluminum is 12 - 30%, and the ICP content of silicon is 4 - 25%; The specific surface area of the transition metal-supported catalytic hydroisomerization catalyst is 211 - 235 m 2 / g.

[0026] In the above transition metal-supported catalytic hydroisomerization catalyst, in the confined environment of the silica-alumina molecular sieve, Ni-Fe-Co may form an alloy structure, and the variable valence characteristics of Fe 2+ / Fe 3+ and Co 2+ / Co 3+ can participate in the redox cycle, and the stable valence state of Ni 2+ helps to stabilize the intermediate state, and Fe 3+ can promote Co 3+ through electron transfer.The generation accelerates hydrogen activation in the hydrocracking reaction. The high electronegativity of Co attracts the electrons of Ni / Fe, forming electron-rich or electron-deficient regions, optimizing the adsorption capacity for reactants (such as long-chain alkanes); the catalyst is synthesized by a one-step hydrothermal method, which can increase the interaction between the metal active component and the support. The microporous structure of the molecular sieve can anchor metal particles (Ni-Co-Fe alloy), preventing high-temperature sintering. At the same time, after Fe / Co is embedded in the molecular sieve framework, Si-OH-Fe / Co bonds are formed, introducing Lewis acid sites, reducing the acid strength, inhibiting cracking side reactions, increasing isomer selectivity. At the same time, the presence of Fe and Co can inhibit the agglomeration of Ni particles, ensuring the hydrogenation and dehydrogenation activity of the catalyst; the nickel-iron-cobalt active component forms multiple synergies with the acidity and pore confinement of the silica-alumina molecular sieve support through electron complementarity, functional division of labor, and redox synergy, significantly improving the activity and selectivity of the hydroisomerization reaction.

[0027] The present invention also provides the application of the above-mentioned transition metal-supported catalytic hydroisomerization catalyst in the hydroisomerization catalytic reaction.

[0028] In a preferred embodiment, using n-octadecane as the raw material, a hydroisomerization catalytic reaction is carried out on it to prepare sustainable aviation fuel (SAF); it includes: loading the transition metal-supported catalytic hydroisomerization catalyst into a fixed-bed reaction tube, heating up for catalyst reduction, after the catalyst reduction is completed, adjusting the reaction temperature, introducing hydrogen and HVO (hydrogenated vegetable oil) for continuous reaction, and then obtaining SAF; the product yield is 93-97%, and the C18 conversion rate is 99.15-99.61%; the proportion of C5-C18 n-alkanes in the sustainable aviation fuel is 26.41-28.79%, and the proportion of C5-C18 isoalkanes is 71.21-73.59%.

[0029] In order to introduce the transition metal-supported catalytic hydroisomerization catalyst, its preparation method and application provided by the embodiments of the present invention more clearly and in detail, the following will be described in combination with specific embodiments.

[0030] Example 1 1) Add 10 parts of nickel nitrate hexahydrate, 5 parts of cobalt nitrate hexahydrate, 8 parts of iron nitrate nonahydrate, 40 parts of aluminum nitrate nonahydrate, 12 parts of phosphoric acid, and 12 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 40 parts of tetraethyl orthosilicate to 100 parts of absolute ethanol, and ultrasonically dissolve it evenly to prepare solution B; 3) Transfer solution A and solution B to a high-pressure reaction kettle, react at a high temperature of 200 °C for 12 hours, then filter and wash to obtain the catalyst precursor, and then extrude the obtained precursor into a mold, and calcine it at a high temperature of 550 °C in a muffle furnace for 4 hours and then cool down to obtain the final catalyst.

[0031] Example 2 1) Add 15 parts of nickel nitrate hexahydrate, 8 parts of cobalt nitrate hexahydrate, 10 parts of iron nitrate nonahydrate, 60 parts of aluminum nitrate nonahydrate, 10 parts of phosphoric acid, and 18 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 30 parts of tetraethyl orthosilicate to 100 parts of absolute ethanol, and ultrasonically dissolve it evenly to prepare solution B; 3) Transfer solution A and solution B to a high-pressure reactor, react at a high temperature of 250 °C for 18 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, and calcine it at a high temperature of 600 °C in a muffle furnace for 6 hours, and then cool down to obtain the final catalyst.

[0032] Example 3 1) Add 8 parts of nickel nitrate hexahydrate, 3 parts of cobalt nitrate hexahydrate, 5 parts of iron nitrate nonahydrate, 80 parts of aluminum nitrate nonahydrate, 8 parts of phosphoric acid, and 10 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 20 parts of tetraethyl orthosilicate to 100 parts of absolute ethanol, and ultrasonically dissolve it evenly to prepare solution B; 3) Transfer solution A and solution B to a high-pressure reactor, react at a high temperature of 150 °C for 6 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, and calcine it at a high temperature of 550 °C in a muffle furnace for 2 hours, and then cool down to obtain the final catalyst.

[0033] Example 4 1) Add 20 parts of nickel nitrate hexahydrate, 10 parts of cobalt nitrate hexahydrate, 16 parts of iron nitrate nonahydrate, 100 parts of aluminum nitrate nonahydrate, 6 parts of phosphoric acid, and 20 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 10 parts of tetraethyl orthosilicate to 100 parts of absolute ethanol, and ultrasonically dissolve it evenly to prepare solution B; 3) Transfer solution A and solution B to a high-pressure reactor, react at a high temperature of 200 °C for 24 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, and calcine it at a high temperature of 550 °C in a muffle furnace for 8 hours, and then cool down to obtain the final catalyst.

[0034] Comparative Example 1 1) Add 10 parts of nickel nitrate hexahydrate, 5 parts of cobalt nitrate hexahydrate, 8 parts of iron nitrate nonahydrate, 15 parts of pseudo-boehmite, 12 parts of phosphoric acid, and 12 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 40 parts of SBA-15 to 100 parts of absolute ethanol, and ultrasonically dissolve it evenly to prepare solution B; 3) Transfer solutions A and B to an autoclave, react at a high temperature of 200 °C for 12 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, calcine it at a high temperature of 550 °C in a muffle furnace for 4 hours, and then cool down to obtain the final catalyst.

[0035] Comparative Example 2 1) Add 10 parts of nickel nitrate hexahydrate, 5 parts of cobalt nitrate hexahydrate, 8 parts of iron nitrate nonahydrate, 12 parts of phosphoric acid, and 12 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Use 100 parts of absolute ethanol as solution B; 3) Transfer solutions A and B to an autoclave, react at a high temperature of 200 °C for 12 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, calcine it at a high temperature of 550 °C in a muffle furnace for 4 hours, and then cool down to obtain the final catalyst. Among them, citric acid can undergo a complexation reaction with metal ions to form a chelate, and a sol-gel catalyst precursor can be formed under high-temperature hydrothermal conditions.

[0036] Comparative Example 3 1) Add 10 parts of nickel nitrate hexahydrate, 40 parts of aluminum nitrate nonahydrate, 12 parts of phosphoric acid, and 12 parts of citric acid to 200 parts of deionized water, and ultrasonically dissolve them fully to prepare solution A; 2) Add 40 parts of tetraethyl orthosilicate to 100 parts of absolute ethanol, and ultrasonically dissolve and mix evenly to prepare solution B; 3) Transfer solutions A and B to an autoclave, react at a high temperature of 200 °C for 12 hours, then filter and wash to obtain the catalyst precursor. Then, extrude the obtained precursor into a shape, calcine it at a high temperature of 550 °C in a muffle furnace for 4 hours, and then cool down to obtain the final catalyst.

[0037] Test Example Weigh 10 g of the final catalysts obtained from the above examples and comparative examples, transfer them to a fixed-bed reaction tube, fill inert fillers (such as silicon carbide, quartz sand, etc.) at the upper and lower parts. After the system is leak-tested, replace the atmosphere with nitrogen and hydrogen respectively. Then, set the hydrogen flow rate to 100 mL / min, raise the temperature to 380 °C, keep it at a constant temperature for reduction for 4 hours, cool down to 300 °C, set the hydrogen flow rate to 60 mL / min, and introduce n-octadecane at a flow rate of 0.2 mL / min. First, stabilize the feed for 12 hours, then continue the reaction for 12 hours, collect the samples to calculate the yield, and take samples for gas chromatography analysis of the reaction conversion rate and isomer selectivity. The results are shown in Table 1. The method for gas chromatography analysis is as follows: chromatographic column HP-5MS, initial column temperature 50 °C, rising to 280 °C at a rate of 3 °C / min, holding for 8 minutes, FID detector, injection volume 0.2 μL, split ratio 39:1, vaporization chamber 250 °C, detector 300 °C.

[0038] Table 1 Results of Gas Chromatographic Analysis

[0039] The proportion of C15-C18 n-alkanes in Table 1 refers to the percentage of C15-C18 n-alkanes in the total amount of C15-C18 n-alkanes and C15-C18 isoalkanes. The proportion of C15-C18 isoalkanes refers to the percentage of C15-C18 isoalkanes in the total amount of C15-C18 n-alkanes and C15-C18 isoalkanes, which reflects the degree of isomerization of the raw materials by the catalyst; C9-C18 are the main components of the bio-aviation fuel product. C9-C18% in Table 1 refers to the percentage content of the obtained C9-C18 in the total product.

[0040] The catalyst was characterized by ICP and BET. ICP test method: Weigh a small amount of catalyst, mix it with nitric acid + hydrofluoric acid + hydrochloric acid, digest it completely in a microwave digestion instrument, dilute it with deionized water, and perform ICP test (inductively coupled plasma mass spectrometer, NexION 1000G). BET test method: Add 50-100 mg to the sample tube, perform degassing pretreatment at 200 °C for 6 h, and then use a specific surface area analyzer NOVA touchTM LX2 to measure the specific surface area. The results are shown in Table 2.

[0041] Table 2 Results of ICP Characterization and BET Characterization

[0042] The following conclusions can be drawn from the results of the examples and comparative examples in Table 1 and Table 2: In the fixed-bed reaction results of the catalysts in Examples 1-4, a very high C18 conversion rate was obtained, along with high isomerization selectivity and low cracking selectivity, and a high-quality aviation fuel product could be obtained with a high yield; By comparing Comparative Example 1 with Example 1, it can be found that although the usage amounts of nickel, cobalt, and iron salts are similar in the preparation, due to the use of a commercially available formed carrier, the interaction between the active components of the actual catalyst and the carrier is poor, resulting in a low loading amount. At the same time, its specific surface area is also lower than that of the self-made catalyst, thus leading to poor conversion rate and selectivity of the reaction and a low yield; By comparing Comparative Example 2 with Example 1, it can be found that after preparing a non-supported catalyst without using a carrier, the specific surface area of the catalyst decreases significantly compared to that of the supported catalyst, which results in fewer active sites on the catalyst surface, thereby affecting the activity and selectivity of the catalyst; By comparing Comparative Example 3 with Example 1, it can be found that if only Ni is used as the active component without using other active components, the lack of synergistic effect between metal active components leads to a decrease in the activity and selectivity of the catalyst.

Claims

1. A preparation method of a transition metal-supported catalytic hydroisomerization catalyst, characterized in that, Comprising: Preparing solution A by mixing nickel nitrate hexahydrate, cobalt nitrate hexahydrate, iron nitrate nonahydrate, aluminum nitrate nonahydrate, phosphoric acid, and citric acid; Preparing solution B by adding tetraethyl orthosilicate to absolute ethanol; Transferring solution A and solution B to a high-pressure reactor, and reacting them fully at 150 - 250 °C to obtain a catalyst precursor; Calcining the catalyst precursor at 550 - 650 °C, and reducing the obtained catalyst by hydrogen to obtain a transition metal-supported catalytic hydroisomerization catalyst; By weight, the dosage of nickel nitrate hexahydrate is any value in the range of 8 - 20 parts, the dosage of cobalt nitrate hexahydrate is any value in the range of 3 - 10 parts, the dosage of iron nitrate nonahydrate is any value in the range of 5 - 16 parts, the dosage of aluminum nitrate nonahydrate is any value in the range of 40 - 100 parts, the dosage of phosphoric acid is any value in the range of 5 - 20 parts, the dosage of citric acid is any value in the range of 5 - 20 parts, and the dosage of tetraethyl orthosilicate is any value in the range of 10 - 40 parts.

2. The preparation method of the transition metal supported catalytic hydroisomerization catalyst according to claim 1, characterized in that, Subjecting solution A and solution B to ultrasonic treatment and then transferring them to a high-pressure reactor.

3. The preparation method of the supported transition metal catalytic hydroisomerization catalyst according to claim 1, characterized in that, Transferring solution A and solution B to a high-pressure reactor, reacting them at 150 - 250 °C for 6 - 24 hours to obtain a catalyst precursor, and then extruding the catalyst precursor into a shape; Calcining the extruded catalyst precursor at 550 - 650 °C for 2 - 8 hours, and reducing the obtained catalyst by hydrogen to obtain a transition metal-supported catalytic hydroisomerization catalyst.

4. A transition metal-supported catalytic hydroisomerization catalyst prepared by the preparation method of the transition metal-supported catalytic hydroisomerization catalyst according to any one of claims 1 - 3.

5. The supported transition metal catalytic hydroisomerization catalyst according to claim 4, wherein In the transition metal-supported catalytic hydroisomerization catalyst, the ICP content of nickel is 7 - 15%, the ICP content of cobalt is 2 - 8%, the ICP content of iron is 3 - 9%, the ICP content of aluminum is 12 - 30%, and the ICP content of silicon is 4 - 25%; The specific surface area of the supported transition metal catalytic hydroisomerization catalyst is 211-235 m 2 / g.

6. Use of the transition metal-supported catalytic hydroisomerization catalyst according to claim 4 or 5 in a hydroisomerization catalytic reaction.

7. Use of the supported transition metal hydroisomerization catalyst according to claim 6 in a hydroisomerization catalytic reaction, characterized in that, Using n-octadecane as a raw material, carrying out a hydroisomerization catalytic reaction on it to prepare bio-aviation fuel; The product yield is 93 - 97%, and the C18 conversion rate is 99.15 - 99.61%; In the bio-aviation fuel, the proportion of C5 - C18 n-alkanes is 26.41 - 28.79%, and the proportion of C5 - C18 isoalkanes is 71.21 - 73.59%.

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