Catalyst for grease hydrodeoxygenation reaction as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for a grease hydrodeoxygenation reaction and a preparation method and application thereof, and the specific preparation steps of the catalyst are as follows: firstly preparing an acidic NbOPO4 carrier by a hydrothermal method, and then loading transition metal by an impregnation method to prepare a bimetallic loaded catalyst. The catalyst is used for preparing long-chain alkane by taking oleic acid as a raw material in the presence of a solvent and the catalyst under the conditions that the reaction temperature is 180-280 DEG C, the H2 initial pressure is 1.0-5.0 MPa and the reaction time is 2-10 hours. Compared with the traditional hydrodeoxygenation catalyst, the catalyst prepared by the invention has both metal sites and acidic sites, has high surface acid content and good stability, can accelerate the hydrodeoxygenation reaction rate of oleic acid under mild conditions, improves the yield of long-chain alkane, and has high economic benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass conversion and utilization, and more specifically, relates to a catalyst for hydrodeoxygenation reaction of oil and its application. Background Art

[0002] Biomass energy has significant advantages, with an extremely wide source and renewable characteristics. However, the composition of bio-oil is highly complex, containing a large number of oxygen-containing functional groups such as carboxyl, aldehyde, phenolic hydroxyl, and methoxy groups. The presence of these functional groups results in a high oxygen content in bio-oils, leading to a low calorific value. The hydrodeoxygenation technology plays a significant role in the treatment of bio-oils. It can reduce the proportion of oxygen-containing compounds in bio-oils and simultaneously reduce the unsaturated bonds in the molecular structure. After such treatment, the chemical properties of bio-oils are optimized, the antioxidant ability is enhanced, and the viscosity and acid value are also reduced.

[0003] In the technical system of hydrodeoxygenation of bio-oils, the core point lies in developing a catalyst with high catalytic activity, high selectivity, and excellent stability. The catalytic efficiency of bio-oil hydrodeoxygenation is determined by the metal active sites of the catalyst. Literature reports that there are mainly two types of bio-oil hydrodeoxygenation catalysts. One is noble metal catalysts, such as Pd, Pt, Rh. Due to their high reaction activity, they also have high hydrodeoxygenation catalytic activity. However, the prices of noble metals are expensive and not suitable for widespread production. Non-noble metal catalysts usually require very high reaction temperatures, and higher reaction temperatures will lead to the cleavage of C-C bonds and reduce the selectivity of products. The other is transition metal catalysts. Zheng et al. (Zheng D, Guo D, Wang Z, et al. Synergistic effect of CoOx and Ni-Co alloy in Ni-Co / SAPO-11 catalysts for the deoxygenation of stearic acids[J]. Chemical Engineering Journal, 2023, 451, 138929.) designed and prepared a bimetal-loaded Ni-Co / SAPO-11 catalyst. Using stearic acid as a model compound, n-alkanes were obtained through hydrodeoxygenation. The selectivity of this catalyst for C17 and C18 alkanes was 90.1%, which was 36.0% higher than that of the single-metal-loaded Ni / SAPO-11 catalyst. This catalyst has Ni-Co alloy and CoOx active sites. Compared with single-metal Ni, the Ni-Co active sites have good activity for hydrogenating carbonyl carbon to form aldehydes, and also have higher adsorption performance and hydrogenation activity. CoOx has a strong adsorption and activation ability for the carboxyl group of stearic acid, thereby reducing the activation energy for removing the hydroxyl group from the carboxyl group and breaking the C-O bond on the carbonyl group. In 2018, Basudeb et al. reported (Sibao Liu, Trent Simonetti, Weiqing Zheng, and Basudeb Saha. Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir-ReOx Bimetallic Catalyst[J]. ChemSusChem, 2018, 11, 1446-1454.) the process of using Ir–ReOx / SiO2 to catalyze the hydrodeoxygenation of vegetable oils and waste cooking oils to prepare alkanes. Chinese Patent CN 118831620A discloses a bio-oil hydrodeoxygenation catalyst, which uses Ni and Co as the main catalytic active metals, and Mo, W, Fe, Cu as the co-catalytic active metals, Ti3C2T x-Mo3C2T x -Nb4C3T x As the carrier. In the hydrodeoxygenation reaction of stearic acid, the obtained catalyst exhibits good catalytic performance, but the preparation process of this catalyst is relatively complex. Chinese Patent CN 105381796B discloses a catalyst for hydrodeoxygenation of organic oxygenates in oil products, its preparation method and application. This catalyst uses two or more of Mo, W, Cu, and Co as active metals, and two or more of Zr, Cr, Mn, Nb, Ga, B, P, V, La, Si, Sn, Se, Te, Mg, and Li as promoters. The carrier is a composite oxide of NiAl or ZnAl with a layered hydrotalcite structure, and is used for hydrodeoxygenation of Fischer-Tropsch synthesis oil raw materials or bio-oil raw materials. The removal rate of oxygenates reaches more than 90%. Therefore, for grease raw materials from different sources and with different components, it is still of great significance to develop a method for efficiently catalyzing the hydrodeoxygenation of various components to prepare alkanes under relatively mild conditions. Summary of the Invention

[0004] Technical Problem: The purpose of the present invention is to develop a catalyst for the hydrodeoxygenation reaction of grease, its preparation method and application; the preparation method of this catalyst is simple, the process flow is short, the manufacturing cost is low, and it has high activity and selectivity under mild reaction conditions.

[0005] Technical Solution: A catalyst for the hydrodeoxygenation reaction of grease according to the present invention comprises a hydrogenation active metal and a solid acid carrier;

[0006] The hydrogenation active metal is one or two of Ni, Mo, Cu, Co, Ce, and Fe, and the solid acid carrier is NbOPO4 with different acidities of pH = 2, 5, and 7.

[0007] The hydrogenation active metal, calculated by the mass of the metal element, is 10% - 30% of the mass of the solid acid carrier.

[0008] The preparation method of the catalyst for the hydrodeoxygenation reaction of grease according to the present invention comprises the following steps:

[0009] Step 1. Using the niobium tartrate soft template method, with an aqueous solution of niobium tartrate as the niobium source and an aqueous solution of diammonium hydrogen phosphate as the phosphorus source, adjusting the pH value of the mixed solution of the niobium source and the phosphorus source to 2, 5, and 7 respectively with phosphoric acid, using cetyltrimethylammonium bromide CTAB as the template agent, stirring evenly, heating at 35 - 45 °C for 1 - 2 h, and then obtaining three different acidic niobium phosphate carriers through aging, suction filtration, washing, drying, and calcination, which are respectively labeled as NbOPO4(pH = 2), NbOPO4(pH = 5), and NbOPO4(pH = 7);

[0010] Step 2. The hydrogenation active metal precursor is dissolved in deionized water by an impregnation method to prepare a precursor mixed solution;

[0011] Step 3. The three different acidic niobium phosphate carriers prepared in Step 1 are respectively placed in the precursor mixed solution prepared in Step 2, impregnated at room temperature for 6 - 24 h, then rotary evaporated at 60 - 80 °C to remove deionized water, and then dried and calcined to obtain three catalyst precursors;

[0012] Step 4. The three prepared catalyst precursors are respectively reduced in a hydrogen atmosphere to finally obtain three catalysts with different acidities, which are the catalysts for the hydrodeoxygenation reaction of oleic acid.

[0013] In Step 1, the aging time is 24 - 48 h, the drying temperature is 80 - 120 °C, and the calcination temperature is 400 - 600 °C.

[0014] In Step 2, the molar concentration of the prepared precursor mixed solution is between 0.05 - 0.6 mol / L.

[0015] In Step 3, the drying temperature is 80 - 120 °C, the calcination temperature is 300 - 600 °C, and the calcination time is 2 - 6 h.

[0016] In Step 4, the flow rate of the hydrogen gas stream is 70 - 120 mL / min, the reduction temperature is between 400 - 600 °C, and the reduction time is 2 - 8 h.

[0017] The application of the catalyst for the hydrodeoxygenation reaction of oils and fats of the present invention uses oleic acid as a raw material, and in the presence of a solvent and the catalyst, long-chain alkanes are prepared under the conditions that the reaction temperature is 180 - 280 °C, the initial pressure of H2 is 1.0 - 5.0 MPa, and the reaction time is 2 - 10 h.

[0018] The solvent is n-hexane.

[0019] Beneficial effects: Compared with the prior art, the hydrodeoxygenation catalyst for oils and fats provided by the present invention has the advantages of simple material acquisition, simple preparation method, short process flow, low manufacturing cost, and can simply and effectively catalyze the hydrodeoxygenation of oils and fats. Moreover, the catalyst prepared by using the technology of the present invention can efficiently convert oils and fats into long-chain alkanes under mild reaction conditions, showing the characteristics of high activity of the catalyst and high selectivity of long-chain alkanes. Specific embodiments

[0020] The content of the present invention will be further described below in conjunction with specific embodiments, but it should not be construed as a limitation to the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well-known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0021] The catalyst for the hydrodeoxygenation reaction of oils and fats of the present invention comprises a hydrogenation active metal and a solid acid support. The hydrogenation active metal is one or two of Ni, Mo, Cu, Co, Ce, and Fe, and the solid acid support is NbOPO4 with different acidities of pH = 2, 5, and 7. The hydrogenation active metal, calculated by the mass of the metal element, is 10% - 30% of the mass of the solid acid support.

[0022] Example 1

[0023] The preparation method of the catalyst for the hydrodeoxygenation reaction of oils and fats of the present invention specifically comprises the following steps:

[0024] First, prepare a 10% Ni - 10% Cu / NbOPO4 (pH = 2) catalyst (the loading amounts of Ni and Cu are both 10% of the mass of NbOPO4 (pH = 2)):

[0025] (1) Weigh 2.66 g of niobium pentoxide and dissolve it in 20 ml of hydrofluoric acid. Load it into a stainless - steel crystallization kettle with a polytetrafluoroethylene lining and react at 100 °C for 7 h. After natural cooling, wash it with 5% ammonia water until it is alkaline to make it completely precipitate, and dissolve it in 40 mL of a tartaric acid solution with a concentration of 0.5 mol / L to obtain a niobium tartrate solution;

[0026] (2) Weigh 1.0 g of cetyltrimethylammonium bromide and dissolve it in 26 ml of deionized water, stir at 40 °C for 1 h. Dissolve 2.64 g of diammonium hydrogen phosphate in 40 ml of water. Mix the niobium tartrate solution and the diammonium hydrogen phosphate solution, then add 1.9 g of phosphoric acid, and then add the template agent solution. Stir at 40 °C for 1 h, then age at 160 °C for 24 h in a stainless - steel crystallization kettle with a polytetrafluoroethylene lining. After natural cooling, filter by suction, wash with deionized water, dry at 100 °C overnight, and calcine at 600 °C for 6 h to obtain the NbOPO4 (pH = 2) support.

[0027] (3) Weigh 0.495 g of nickel nitrate hexahydrate and 0.38 g of copper nitrate trihydrate and dissolve them in 50 ml of deionized water, and stir ultrasonically to dissolve them; add 1 g of the NbOPO4 (pH = 2) support, mix well, impregnate at room temperature for 12 h, rotary evaporate at 80 °C. After stirring, put it into a blast drying oven and dry at 120 °C for 12 h, then put it into a muffle furnace and calcine at 500 °C for 4 h to obtain the catalyst precursor.

[0028] (4) Place the catalyst precursor in a tubular furnace, introduce hydrogen at a gas flow rate of 70 ml / min for 30 min, and then reduce it at a high temperature of 550 °C for 3 h under the condition of introducing hydrogen to obtain a 10% Ni-10% Cu / NbOPO4 (pH = 2) metal catalyst (the loadings of Ni and Cu are both 10% of the mass of NbOPO4 (pH = 2)).

[0029] Secondly, test the hydrodeoxygenation reaction performance of the catalyst in a high-pressure reactor; add 1 g of oleic acid, 0.2 g of 10% Ni-10% Cu / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 3 MPa of H2, set the reaction temperature at 260 °C, the stirring speed at 350 r / min, and the reaction time at 7 h.

[0030] Finally, after the reaction is completed, quickly cool the temperature of the high-pressure reactor to room temperature, vent the gas in the reactor, open the reactor, filter the catalyst and then take out the liquid product; the obtained liquid product is qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatography. The conversion rate of oleic acid is 99.5%, the yields of heptadecane and octadecane are 93.3%, and the selectivity is 93.8%.

[0031] Example 2

[0032] Compared with Example 1, Example 2 changes the initial hydrogen pressure in the test of hydrodeoxygenation reaction performance.

[0033] The catalyst preparation method is the same as that in Example 1. Place 10% Ni-10% Cu / NbOPO4 (pH = 2) in a tubular furnace at 550 °C. After introducing hydrogen and reducing it for 3 h, test the hydrogenation reaction performance of the catalyst in a micro high-pressure reactor. Add 1 g of oleic acid, 0.2 g of 10% Ni-10% Cu / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 2 MPa of H2, set the reaction temperature at 260 °C, the stirring speed at 350 r / min, and the reaction time at 7 h.

[0034] After the reaction is completed, quickly cool the temperature of the high-pressure reactor to room temperature, vent the gas in the reactor, open the reactor, filter the catalyst and then take out the liquid product; the obtained liquid product is qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatography. The conversion rate of oleic acid is 83.2%, the yields of heptadecane and octadecane are 75.4%, and the selectivity is 90.6%.

[0035] Within a certain range, the influence of the initial hydrogen pressure on the hydrodeoxygenation reaction of oleic acid shows a positive correlation. The higher the initial hydrogen pressure, the higher the conversion rate of oleic acid and the yields of n-heptadecane and octadecane will be.

[0036] Example 3

[0037] Compared with Example 1, in Example 3, the reaction temperature and reaction time in the hydrodeoxygenation reaction performance test were changed.

[0038] The catalyst preparation method was the same as that in Example 1. 10% Ni-10% Cu / NbOPO4 (pH = 2) was placed in a tube furnace at 550 °C. After being reduced with hydrogen for 3 h, the hydrogenation reaction performance test of the catalyst was carried out in a micro high-pressure reactor. 1 g of oleic acid, 0.2 g of 10% Ni-10% Cu / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent were added to the high-pressure reactor, mixed evenly, sealed, and the air in the reactor was replaced with N2 three times, and then the nitrogen in the reactor was replaced with H2 three times. After that, 3 MPa of H2 was charged, the reaction temperature was set at 280 °C, the stirring speed was 350 r / min, and the reaction time was 5 h.

[0039] After the reaction ended, the temperature of the high-pressure reactor was quickly cooled to room temperature, the gas in the reactor was vented, the reactor was opened, and the liquid product was taken out after filtering the catalyst; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatography. The conversion rate of oleic acid was 99.9%, the yields of heptadecane and octadecane were 93.6%, and the selectivity was 93.6%.

[0040] Example 4

[0041] Compared with Example 1, in Example 4, 0.740 g of ammonium molybdate tetrahydrate was weighed instead of 0.380 g of copper nitrate trihydrate in step (3) of the catalyst preparation method, and the high-temperature reduction at 550 °C for 3 h in step (4) was changed to the high-temperature reduction at 600 °C for 2 h. After reduction, a 10% Ni-20% Mo / NbOPO4 (pH = 2) catalyst (the loadings of Ni and Mo were 10% and 20% of the mass of NbOPO4 (pH = 2) respectively) was obtained.

[0042] Change the reaction temperature in the hydrodeoxygenation reaction performance test. Place 10% Ni-20% Mo / NbOPO4 (pH = 2) in a 550 °C tubular furnace, and after introducing hydrogen for reduction for 3 h, conduct the hydrodehydrogenation reaction performance test of the catalyst in a micro high-pressure reactor. Add 1 g of oleic acid, 10% Ni-20% Mo / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 3 MPa of H2, set the reaction temperature to 180 °C, the stirring speed to 350 r / min, and the reaction time to 7 h.

[0043] After the reaction is completed, quickly cool the temperature of the high-pressure reactor to room temperature, vent the gas in the reactor, open the reactor, filter the catalyst and then take out the liquid product; the obtained liquid product is qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid is 63.7%, the yields of heptadecane and octadecane are 49.8%, and the selectivity is 78.2%.

[0044] Example 5

[0045] Compared with Example 1, in Example 5, 0.495 g of nickel nitrate hexahydrate weighed in step (3) of the catalyst preparation method was changed to 0.298 g of nickel nitrate hexahydrate, and 0.380 g of copper nitrate trihydrate weighed was changed to 0.310 g of cerium nitrate hexahydrate. The carrier calcination temperature in step (2) was changed from 600 °C to 400 °C, and a 5% Ni-10% Ce / NbOPO4 (pH = 2) catalyst (the loadings of Ni and Ce are 5% and 10% of the mass of NbOPO4 (pH = 2) respectively) was obtained after reduction.

[0046] Change the initial hydrogen pressure and reaction time in the hydrodeoxygenation reaction performance test. Place 5% Ni-10% Ce / NbOPO4 (pH = 2) in a 550 °C tubular furnace, and after introducing hydrogen for reduction for 3 h, conduct the hydrodehydrogenation reaction performance test of the catalyst in a micro high-pressure reactor. Add 1 g of oleic acid, 5% Ni-10% Ce / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 1.0 MPa of H2, set the reaction temperature to 260 °C, the stirring speed to 350 r / min, and the reaction time to 10 h.

[0047] After the reaction is completed, quickly cool the temperature of the high-pressure reactor to room temperature, vent the gas in the reactor, open the reactor, filter the catalyst and then take out the liquid product; the obtained liquid product is qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid is 75.5%, the yields of heptadecane and octadecane are 69.8%, and the selectivity is 92.5%.

[0048] Example 6

[0049] Compared with Example 1, in Example 6, in step (3) of the catalyst preparation method, the weighing of 0.495 g of nickel nitrate hexahydrate was changed to the weighing of 0.298 g of nickel nitrate hexahydrate, and the weighing of 0.380 g of copper nitrate trihydrate was changed to the weighing of 0.202 g of cobalt chloride hexahydrate. In step (4), the high-temperature reduction at 550 °C for 3 h was changed to the high-temperature reduction at 400 °C for 8 h. After reduction, a 5% Ni-5% Co / NbOPO4 (pH = 2) metal catalyst was obtained (the loadings of Ni and Co were 5% and 5% of the mass of NbOPO4 (pH = 2) respectively).

[0050] The initial hydrogen pressure in the hydrodeoxygenation reaction performance test was changed. The 5% Ni-5% Co / NbOPO4 (pH = 2) was placed in a tube furnace at 550 °C. After being reduced by hydrogen for 3 h, the hydrogenation reaction performance test of the catalyst was carried out in a micro high-pressure reactor. 1 g of oleic acid, 5% Ni-5% Co / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent were added to the high-pressure reactor, mixed evenly, sealed, and the air in the reactor was replaced with N2 three times, and then the nitrogen in the reactor was replaced with H2 three times. After that, H2 with a pressure of 5.0 MPa was charged, the reaction temperature was set at 260 °C, the stirring speed was 350 r / min, and the reaction time was 7 h.

[0051] After the reaction ended, the temperature of the high-pressure reactor was quickly cooled to room temperature, the gas in the reactor was vented, the reactor was opened, and the liquid product was taken out after filtering the catalyst; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid was 87.9%, the yields of heptadecane and octadecane were 81.1%, and the selectivity was 92.3%.

[0052] Example 7

[0053] Compared with Example 1, in Example 6, in step (3) of the catalyst preparation method, the weighing of 0.380 g of copper nitrate trihydrate was changed to the weighing of 0.483 g of iron chloride hexahydrate. After reduction, a 10% Ni-10% Fe / NbOPO4 (pH = 2) metal catalyst was obtained (the loadings of Ni and Fe were 10% and 10% of the mass of NbOPO4 (pH = 2) respectively).

[0054] Change the reaction temperature in the hydrodeoxygenation reaction performance test. Place 10% Ni-10% Fe / NbOPO4 (pH = 2) in a 550 °C tubular furnace, and after introducing hydrogen for reduction for 3 h, conduct the hydrodehydrogenation reaction performance test of the catalyst in a micro high-pressure reactor. Add 1 g of oleic acid, 10% Ni-10% Fe / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 3.0 MPa of H2, set the reaction temperature to 270 °C, the stirring speed to 350 r / min, and the reaction time to 7 h.

[0055] After the reaction is completed, quickly cool the temperature of the high-pressure reactor to room temperature, vent the gas in the reactor, open the reactor, filter the catalyst and then take out the liquid product; the obtained liquid product is qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid is 83.7%, the yields of heptadecane and octadecane are 76.2%, and the selectivity is 91.0%.

[0056] There will be certain differences in the hydrodeoxygenation effects of different metals. For transition metals, the hydrodeoxygenation effect of the bimetallic nickel-copper catalyst is the best. Therefore, in Example 7, the reaction temperature was increased, but the hydrodeoxygenation effect is not as good as that in Example 1, indicating that after only increasing the temperature, the hydrodeoxygenation effect of the bimetallic nickel-iron catalyst is not as good as that of the bimetallic nickel-copper catalyst.

[0057] Comparative Example 1

[0058] Compared with Example 1, in Comparative Example 1, 0.495 g of nickel nitrate hexahydrate and 0.38 g of copper nitrate trihydrate weighed in step (3) of the catalyst preparation method were changed to 0.495 g of nickel nitrate hexahydrate. After reduction, a 10% Ni / NbOPO4 (pH = 2) metal catalyst (the loading amount of Ni is 10% of the mass of NbOPO4 (pH = 2)) was obtained.

[0059] Place 10% Ni / NbOPO4 (pH = 2) in a 550 °C tubular furnace, and after introducing hydrogen for reduction for 3 h, conduct the hydrodehydrogenation reaction performance test of the catalyst in a micro high-pressure reactor. Add 1 g of oleic acid, 10% Ni / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent into the high-pressure reactor, mix evenly, seal the reactor, displace the air in the reactor with N2 three times, and then displace the nitrogen in the reactor with H2 three times. After that, charge 3.0 MPa of H2, set the reaction temperature to 260 °C, the stirring speed to 350 r / min, and the reaction time to 7 h.

[0060] After the reaction was completed, the temperature of the autoclave was rapidly cooled to room temperature, the gas in the autoclave was vented, the autoclave was opened, and the catalyst was filtered before taking out the liquid product; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid was 62.3%, the yield of heptadecane and octadecane was 56.9%, and the selectivity was 91.3%.

[0061] Comparative Example 2

[0062] Compared with Example 1, in Comparative Example 2, 0.495 g of nickel nitrate hexahydrate and 0.38 g of copper nitrate trihydrate weighed in step (3) of the catalyst preparation method were changed to 0.38 g of copper nitrate trihydrate. After reduction, a 10% Cu / NbOPO4 (pH = 2) metal catalyst was obtained (the loading amount of Cu was 10% of the mass of NbOPO4 (pH = 2)).

[0063] The 10% Cu / NbOPO4 (pH = 2) was placed in a tube furnace at 550 °C and reduced with hydrogen for 3 h, and then the hydrogenation reaction performance of the catalyst was tested in a micro-autoclave. 1 g of oleic acid, 10% Cu / NbOPO4 (pH = 2) metal catalyst and 10 g of n-hexane solvent were added to the autoclave, mixed evenly, sealed, and the air in the autoclave was replaced with N2 three times, and then the nitrogen in the autoclave was replaced with H2 three times. After that, 3.0 MPa of H2 was charged, the reaction temperature was set at 260 °C, the stirring speed was 350 r / min, and the reaction time was 7 h.

[0064] After the reaction was completed, the temperature of the autoclave was rapidly cooled to room temperature, the gas in the autoclave was vented, the autoclave was opened, and the catalyst was filtered before taking out the liquid product; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid was 24.3%, the yield of heptadecane and octadecane was 19.1%, and the selectivity was 78.6%.

[0065] Comparative Example 3

[0066] Compared with Example 1, in Comparative Example 3, 1.9 g of phosphoric acid added in step (2) of the catalyst preparation method was changed to 1.2 g of phosphoric acid. After reduction, a 10% Ni-10% Cu / NbOPO4 (pH = 5) metal catalyst was obtained (the loading amounts of Ni and Cu were both 10% of the mass of NbOPO4 (pH = 5)).

[0067] 10% Ni-10% Cu / NbOPO4 (pH = 5) was placed in a tube furnace at 550 °C. After being reduced with hydrogen for 3 h, the hydrogenation reaction performance of the catalyst was tested in a micro high-pressure reactor. 1 g of oleic acid, 10% Ni-10% Cu / NbOPO4 (pH = 5) metal catalyst and 10 g of n-hexane solvent were added to the high-pressure reactor, mixed evenly, sealed, and the air in the reactor was replaced with N2 three times, and then the nitrogen in the reactor was replaced with H2 three times. After that, 3.0 MPa of H2 was charged, the reaction temperature was set at 260 °C, the stirring speed was 350 r / min, and the reaction time was 7 h.

[0068] After the reaction was completed, the temperature of the high-pressure reactor was quickly cooled to room temperature, the gas in the reactor was vented, the reactor was opened, and the liquid product was taken out after filtering the catalyst; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid was 79.3%, the yield of heptadecane and octadecane was 71.1%, and the selectivity was 89.7%.

[0069] Comparative Example 4

[0070] Compared with Example 1, in Comparative Example 4, 1.9 g of phosphoric acid added in step (2) of the catalyst preparation method was not added, and after reduction, 10% Ni-10% Cu / NbOPO4 (pH = 7) metal catalyst was obtained (the loading amounts of Ni and Cu were both 10% of the mass of NbOPO4 (pH = 7)).

[0071] 10% Ni-10% Cu / NbOPO4 (pH = 7) was placed in a tube furnace at 550 °C. After being reduced with hydrogen for 3 h, the hydrogenation reaction performance of the catalyst was tested in a micro high-pressure reactor. 1 g of oleic acid, 10% Ni-10% Cu / NbOPO4 (pH = 7) metal catalyst and 10 g of n-hexane solvent were added to the high-pressure reactor, mixed evenly, sealed, and the air in the reactor was replaced with N2 three times, and then the nitrogen in the reactor was replaced with H2 three times. After that, 3.0 MPa of H2 was charged, the reaction temperature was set at 260 °C, the stirring speed was 350 r / min, and the reaction time was 7 h.

[0072] After the reaction was completed, the temperature of the high-pressure reactor was quickly cooled to room temperature, the gas in the reactor was vented, the reactor was opened, and the liquid product was taken out after filtering the catalyst; the obtained liquid product was qualitatively analyzed by gas chromatography-mass spectrometry and quantitatively analyzed by gas chromatograph. The conversion rate of oleic acid was 59.3%, the yield of heptadecane and octadecane was 52.4%, and the selectivity was 88.4%.

Claims

1. A catalyst for oil hydrodeoxygenation reaction, characterized in that: The catalyst comprises a hydrogenation active metal and a solid acid support.

2. The catalyst for oil hydrodeoxygenation reaction according to claim 1, characterized in that: The hydrogenation active metal is one or two of Ni, Mo, Cu, Co, Ce and Fe, and the solid acid carrier is NbOPO4 with different acidity of pH=2, 5 and 7.

3. The catalyst for oil hydrodeoxygenation reaction according to claim 1, characterized in that: The hydrogenation active metal, calculated on the basis of the mass of the metal element, accounts for 10% to 30% of the mass of the solid acid carrier.

4. A method for preparing a catalyst for oil hydrodeoxygenation reaction as claimed in claim 1, 2 or 3, characterized in that: The preparation method comprises the following steps: Step 1. Using tartrate niobium soft template method, using tartrate niobium aqueous solution as niobium source, diammonium phosphate aqueous solution as phosphorus source, adjusting the pH value of the mixed solution of niobium source and phosphorus source to 2, 5 and 7 respectively with phosphoric acid, using hexadecyltrimethylammonium bromide (CTAB) as template agent, stirring evenly, heating at 35-45° C. for 1-2 hours, and then aging, filtering, washing, drying and calcining to obtain three niobium phosphate supports with different acidity, which are marked as NbOPO4 (pH=2), NbOPO4 (pH=5) and NbOPO4 (pH=7) respectively; Step 2. dissolving the hydrogenation active metal precursor in deionized water by an impregnation method to prepare a precursor mixed solution; Step 3. The three niobium phosphate supports with different acidity prepared in step 1 are placed in the precursor mixed solution prepared in step 2 respectively, immersed at room temperature for 6 to 24 hours, and then rotary evaporated at 60 to 80° C. to remove deionized water, and then dried and calcined to obtain three catalyst precursors; Step 4: The three catalyst precursors are reduced separately in a hydrogen atmosphere to finally obtain three catalysts with different acidity, which are catalysts for oleic acid hydrodeoxygenation reaction.

5. The method for preparing a catalyst for oil hydrodeoxygenation reaction according to claim 4, characterized in that: In step 1, the aging time is 24 to 48 hours, the drying temperature is 80 to 120° C., and the calcination temperature is 400 to 600° C.

6. The method for preparing a catalyst for oil hydrodeoxygenation reaction according to claim 4, characterized in that: In step 2, the molar concentration of the prepared precursor mixed solution is between 0.05 and 0.6 mol / L.

7. The method for preparing a catalyst for oil hydrodeoxygenation reaction according to claim 4, characterized in that: In step 3, the drying temperature is 80-120° C., the calcination temperature is 300-600° C., and the calcination time is 2-6 hours.

8. The method for preparing a catalyst for oil hydrodeoxygenation reaction according to claim 4, characterized in that: In step 4, the flow rate of the hydrogen gas flow is 70 to 120 mL / min, the reduction temperature is between 400 and 600° C., and the reduction time is 2 to 8 hours.

9. Use of the catalyst for oil hydrodeoxygenation reaction as claimed in claim 1, 2 or 3, characterized in that: Long-chain alkanes are prepared using oleic acid as a raw material in the presence of a solvent and the catalyst at a reaction temperature of 180 to 280° C., an initial H2 pressure of 1.0 to 5.0 MPa, and a reaction time of 2 to 10 hours.

10. The use of the catalyst for oil hydrodeoxygenation reaction according to claim 9, characterized in that: The solvent is n-hexane.