Method for preparing C18 n-alkanes from animal and vegetable oil

Abstract

The invention provides a method for preparing C18 n-alkanes from animal and vegetable oil, which comprises the following steps: carrying out hydrogenation dehydration reaction on the animal and vegetable oil under the action of a catalyst to obtain the C18 n-alkanes, wherein the catalyst comprises a carrier and active components, the carrier comprises magnesium aluminate spinel, the active components comprise molybdenum and nickel, and the molar ratio of molybdenum to nickel is (85-100): 1. According to the present invention, the magnesium aluminate spinel is adopted as the carrier, the molybdenum and the nickel are adopted as the active components, and the molar ratio of the molybdenum to the nickel is controlled in the range of 85-100: 1, such that the conversion rate is high and the C18 n-alkane selectivity is high when the catalyst is used for preparing the n-alkane from the animal and plant oil.

Description

Technical Field

[0001] The invention belongs to the field of chemical reagent production and relates to a method for preparing C18 normal alkanes by using animal and vegetable oils as raw materials through hydrogenation and deoxygenation. Background Art

[0002] Normal alkanes are called liquid paraffin because they are transparent, colorless or light yellow liquids at room temperature. According to the fraction, they can be divided into light liquid paraffin (abbreviated as light wax, C9~C13) and heavy liquid paraffin (abbreviated as heavy wax, C14~C16). C18 normal alkanes are mainly used in phase change materials, pharmaceutical cold chain logistics, phase change energy storage buildings, phase change microcapsules for textiles and temperature control of electronic components. C18 normal alkanes can be used as solvents and can also be used in the separation and analysis of low-level hydrocarbons, dewaxing solvents, machining oils, base oils for special rust-proof oils, metal processing base oils, metal cleaning agents, gas chromatography reference materials and stationary liquids; they can also be used in gas storage functions such as hydrogen storage and nitrogen storage.

[0003] In industrialization, the raw materials for producing normal alkanes are mainly petroleum wax and Fischer-Tropsch synthetic oil wax. When producing normal alkanes from petroleum wax and Fischer-Tropsch synthetic oil wax, because they contain complex components such as olefins, isoparaffins, cycloparaffins, aromatics, and oxygen-, sulfur-, and nitrogen-containing compounds, they need to be removed and purified through deep hydrorefining, distillation, normal / isoparaffin separation and other processing processes. The production process is complex and the process conditions are harsh.

[0004] The types of methods for preparing normal alkanes that exist at present are as follows: 1. A mixture of normal alkanes is prepared by dewaxing molecular sieves or urea, and then the normal alkanes are separated by freezing in sections. Among them, the typical process is the Molex process of UOP Company, which first fractionates the raw materials and takes the middle distillate as the raw material; the raw materials are then hydro-refined to remove impurities such as sulfur, nitrogen and oxygen; then the synthetic 5A zeolite molecular sieve is used as an adsorbent to adsorb normal alkanes in the liquid phase, and then the molecular sieve is washed with low molecular weight alkanes as a desorbent. And the isopropanol-urea dewaxing process, which mainly uses the normal alkanes in the oil and urea in an isopropanol solution to react to form a solid complex, which is separated from the oil, and then the complex is decomposed at high temperature to obtain normal alkanes and urea, and the urea is recycled. 2. The Wurtz reaction is used to prepare symmetrical normal alkanes. 3. The iodinated alkane reduction method is used. 4. The halogenated alkane method is linked using petroleum ether, n-hexane and n-heptane as solvents. Although the above methods can prepare the corresponding normal alkanes, each method has certain problems: for example, the process conditions of the first method are relatively complex, and the requirements for certain equipment and materials are relatively high, and the investment scale is large, and it is only suitable for large-scale petrochemical production; the second method is suitable for symmetrical even-numbered alkanes, and the products need to be repeatedly extracted with ether, and raw materials with a carbon chain of 18 or more are not easy to obtain; the third and fourth methods are highly dangerous to operate, and petroleum ether is very easy to erupt in the violent reaction between metallic sodium and alkyl halides, and the safety factor is low and the cost is relatively high.

[0005] In addition to using petroleum wax and Fischer-Tropsch synthetic oil wax as raw materials to produce monomer n-alkanes, there is also the hydrodeoxygenation of animal and vegetable oil esters to produce monomer n-alkanes. However, there are many problems such as low conversion rate of animal and vegetable oils into monomer alkanes, low selectivity, side reactions such as decarbonylation and decarboxylation, and the presence of by-products such as C15 and C17 in the products.

[0006] CN201110353466 discloses a method for preparing n-octadecane from stearic acid, wherein the catalyst is a palladium / carbon nanotube catalyst, the reactor is operated intermittently, single-stage pressed stearic acid is used as the raw material, the conversion rate is 82%, and the octadecane selectivity is 76%; two-stage pressed stearic acid is used as the raw material, the conversion rate is 85%, and the octadecane selectivity is 80%; three-stage pressed stearic acid is used as the raw material, the conversion rate is 98%, and the octadecane selectivity is 95%.

[0007] CN200910100260 discloses a method for preparing alkanes from higher fatty acids, with fatty acid methyl esters of 8 to 22 carbons as raw materials, carrying out hydrodeoxygenation to produce alkanes, but in the resulting product, the carbon major part in the fatty acid is removed, except for decarbonylation and decarboxylation reactions, there are also other side reactions, such as taking methyl stearate (methyl octadecanoate) as raw material, the total yield of heptadecane and octadecane obtained is only 75% when the conversion rate is up to 98%. Such as taking ethyl stearate (ethyl octadecanoate) as raw material, the total yield of heptadecane and octadecane obtained is only 82% when the conversion rate is up to 99%.

[0008] CN202110961795 discloses a method for preparing a bio-based normal alkane phase change material, wherein fatty acid glyceride is reacted under the action of an acidic solid catalyst to obtain normal alkanes, and n-pentadecane, n-hexadecane, n-heptadecane and n-octadecane are separated after distillation to obtain normal alkanes with a single carbon number, and the purity of the normal alkanes is more than 98%. However, in its hydrodeoxygenation reaction, a large amount of decarbonylation / carboxylation reaction occurs, and the selectivity is not high, resulting in the production of a large amount of n-pentadecane and n-heptadecane.

[0009] CN201210322774 discloses a method for preparing alkanes by hydrodeoxygenation of non-edible animal and vegetable oils, using a molybdenum-nickel catalyst containing 3-5wt% cerium oxide and silicon oxide to obtain mixed alkanes whose main components are C15-C18, with an alkane yield of about 82% and a C15-C18 mixed alkane yield of about 80%. Decarbonylation and decarboxylation reactions occur in the prepared mixed aromatics to generate C15 and C17 alkanes, and the selectivity is not high.

[0010] CN202110518934 discloses a method for preparing high-purity C16 and C18 normal monoalkanes, which utilizes diluted vegetable oil to produce C16 and C18 high-purity normal monoalkanes through a double-bed hydrodeoxygenation reaction combined with a distillation separation process. The upper bed is loaded with a molybdenum-nickel catalyst and the lower bed is loaded with a platinum catalyst. The double-bed catalyst solves the problem of high heat release and uneven bed temperature during the hydrodeoxygenation reaction of vegetable oil; the prepared target product has high purity and can significantly improve the utilization value of vegetable oil. However, the content of n-hexadecane and n-octadecane in the hydrodeoxygenation product accounts for 84%, and the selectivity is not high.

[0011] Therefore, further research on the preparation of C18 normal alkanes is needed in this field. Summary of the invention

[0012] The main purpose of the present invention is to provide a method for preparing C18 normal alkanes from animal and vegetable oils and fats, so as to solve the problems of low conversion rate, low selectivity and easy occurrence of side reactions such as decarbonylation and decarboxylation when preparing normal alkanes from animal and vegetable oils and fats in the prior art.

[0013] In order to achieve the above object, the present invention provides a method for preparing C18 normal alkanes from animal and vegetable oils and fats, comprising the following steps:

[0014] The animal and vegetable oils are subjected to a hydrogenation dehydration reaction under the action of a catalyst to obtain C18 normal alkanes;

[0015] The catalyst comprises a carrier and an active component, wherein the carrier comprises magnesium aluminum spinel, and the active component comprises molybdenum and nickel, and the molar ratio of molybdenum to nickel is 85 to 100:1.

[0016] The method for preparing C18 normal alkanes from animal and plant oils and fats of the present invention, wherein the catalyst also includes a modification aid, and the modification aid is at least one of iron, cobalt, and cerium.

[0017] The method for preparing C18 normal alkanes from animal and vegetable oils of the present invention, wherein the reaction temperature of the hydrogenation dehydration reaction is 320-400°C, the reaction pressure is 1-4MPa, and the mass space velocity is 0.5-2h -1 , the volume ratio of hydrogen to oil is 100-400:1.

[0018] In the method for preparing C18 normal alkanes from animal and vegetable oils and fats of the present invention, a solvent is added to the hydrogenation dehydration reaction, and the volume ratio of the solvent to the reaction mixture is 70-95%.

[0019] The method for preparing C18 normal alkanes from animal and vegetable oils and fats of the present invention comprises the following steps: in the catalyst, the active components are calculated as molybdenum oxide and nickel oxide, and the mass of the active components accounts for 10-30% of the mass of the carrier.

[0020] The method for preparing C18 normal alkanes from animal and vegetable oils of the present invention comprises the following steps: in the catalyst, the modification aid is calculated as metal oxide, and the modification aid accounts for 0.3-0.7% of the mass of the catalyst.

[0021] The method for preparing C18 normal alkanes from animal and vegetable oils and fats of the present invention, wherein the method for preparing the catalyst comprises the following steps:

[0022] Step 1, preparing magnesium aluminum spinel;

[0023] Step 2, the magnesium aluminum spinel, aluminum hydroxide dry glue, and sesbania powder are mixed, an inorganic acid is added to extrudates, and calcined to obtain a carrier;

[0024] Step 3, impregnating the carrier with a solution containing molybdenum and nickel active components to obtain a catalyst.

[0025] The method for preparing C18 normal alkanes from animal and vegetable oils and fats of the present invention, wherein the preparation of magnesium aluminum spinel is: a magnesium source, an aluminum source, a complexing agent, and citric acid are mixed and roasted to obtain the magnesium aluminum spinel.

[0026] The method for preparing C18 normal alkanes from animal and vegetable oils and fats of the present invention further comprises the step of impregnating the carrier with an organosilicon solution before impregnating the carrier with the active component.

[0027] The method for preparing C18 normal alkanes from animal and plant fats and oils of the present invention, wherein the method for preparing the catalyst further comprises the steps of impregnating the catalyst obtained in step 3 with a solution containing a modification aid, and then drying and calcining.

[0028] Beneficial effects of the present invention:

[0029] The catalyst of the present invention uses magnesium aluminum spinel as a carrier, molybdenum and nickel as active components, and controls the molar ratio of molybdenum to nickel within the range of 85 to 100:1, so that when the catalyst of the present invention is used for preparing normal alkanes from animal and vegetable oils and fats, the conversion rate is high and the selectivity of C18 normal alkanes is high. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is described in detail below. The following implementation modes are implemented on the premise of the technical scheme of the present invention, and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following implementation modes. The structures or experimental methods of specific conditions are not specified in the following implementation modes, and generally conventional conditions are followed.

[0031] The present invention provides a method for preparing C18 normal alkanes from animal and vegetable oils and fats, comprising the following steps:

[0032] The animal and vegetable oils are subjected to a hydrogenation dehydration reaction under the action of a catalyst to obtain C18 normal alkanes;

[0033] The catalyst comprises a carrier and an active component, wherein the carrier comprises magnesium aluminum spinel, and the active component comprises molybdenum and nickel, and the molar ratio of molybdenum to nickel is 85 to 100:1.

[0034] The catalyst of the present invention uses magnesium aluminum spinel as a carrier, molybdenum and nickel as active components, and controls the molar ratio of molybdenum to nickel within the range of 85 to 100:1. Therefore, when the catalyst of the present invention is used for preparing normal alkanes from animal and vegetable oils and fats, the animal and vegetable oils and fats mainly undergo hydrogenation and dehydration reactions, avoiding the occurrence of hydrogenation decarbonylation or decarboxylation side reactions, thereby improving the selectivity of C18 normal alkanes.

[0035] In detail, there are two ways to hydrodeoxygenate animal and vegetable oils, namely hydrodehydration and hydrodecarbonylation / carboxylation. When hydrodehydration occurs, the oxygen in the fatty acid ester generates water, and the fatty acid carbon chain does not break, generating n-hexadecane and n-octadecane, with a higher total yield of n-hexadecane and n-octadecane. When hydrodecarbonylation / carboxylation occurs, the oxygen in the fatty acid ester generates CO or CO 2 , the fatty acid carbon chain ends are broken, and n-pentadecane and n-heptadecane are generated by reaction, and the total yield of n-pentadecane and n-heptadecane will be higher. The present invention improves the catalyst to make the animal and plant oils mainly undergo hydrogenation and dehydration reaction.

[0036] The present invention does not specifically limit the magnesium-aluminum spinel, and it can be a commercially available product. In one embodiment, the magnesium-aluminum spinel of the present invention is prepared by the following method:

[0037] A magnesium source, an aluminum source, a complexing agent and citric acid are mixed and calcined to obtain magnesium-aluminum spinel.

[0038] The present invention does not specifically limit the magnesium source and the aluminum source. For example, the magnesium source is magnesium nitrate, and the aluminum source is aluminum nitrate. The complexing agent is, for example, dodecyltrimethylammonium bromide, which is not specifically limited in the present invention. In one embodiment, water is further added during the mixing process of the present invention, and the molar ratio of the magnesium source, the aluminum source, the complexing agent, the citric acid and the water is 1:1-3:4-8:0.01-0.05:60-75, and the preferred molar ratio is 1:2:6:0.01:70.

[0039] In one embodiment, the present invention mixes a magnesium source, an aluminum source, a complexing agent, and citric acid, stirs for 2 to 3 hours at 60-90° C. until the solution becomes a gel, then stands at room temperature for a period of time, puts in an oven for aging, and then roasts at 600 to 800° C. to obtain magnesium aluminum spinel. In another embodiment, the roasting temperature is 680-720° C., the heating rate is 2 to 3° C. / min, and the roasting time is 6 to 10 hours.

[0040] In one embodiment, the catalyst carrier of the present invention further comprises alumina, and the preparation method of the carrier comprises: uniformly mixing magnesium aluminum spinel, aluminum hydroxide dry glue, and sesbania powder, then adding inorganic acid to extrude strips, and roasting to obtain the catalyst carrier.

[0041] Among them, the mass ratio of magnesium aluminum spinel, aluminum hydroxide dry glue and sesbania powder is, for example, 5-7:1.2-2.0:0.2-0.4, preferably 6:1.5:0.3, the inorganic acid is, for example, dilute nitric acid, the mass concentration of dilute nitric acid is, for example, 2%, and the ratio of dilute nitric acid to the mixture of magnesium aluminum spinel, aluminum hydroxide dry glue and sesbania powder is, for example, 1.0 mL / g.

[0042] The present invention does not impose any particular limitation on the calcination temperature during the preparation of the catalyst carrier, and the calcination temperature is, for example, 680-720°C.

[0043] In one embodiment, before the active component is loaded on the carrier of the present invention, the further step includes: impregnating the carrier with an organosilicon solution.

[0044] The organosilicon is, for example, alkoxysilane, more preferably tetraethoxysilane. The concentration of the organosilicon solution is, for example, 0.005-0.05 g / ml, preferably 0.01-0.02 g / ml. The impregnation method is, for example, equal volume impregnation, the impregnation temperature is, for example, 20-30° C., the impregnation time is, for example, 20-30 min, and the impregnation is followed by drying, the drying temperature is, for example, 110-150° C., and the drying time is, for example, 3-7 h.

[0045] In the catalyst of the present invention, the active component is loaded on the carrier, the active component includes molybdenum and nickel, and the molar ratio of molybdenum to nickel is 85-100:1.

[0046] The present invention does not particularly limit the manner in which the active component is loaded on the carrier, for example, by impregnation, which may be equal volume impregnation, excess impregnation, etc.

[0047] In one embodiment, the method of loading an active component onto a carrier of the present invention comprises:

[0048] The molybdenum precursor and the nickel precursor are dissolved in water to prepare an impregnation solution, and then the carrier and the impregnation solution are mixed, stirred, dried, and calcined to obtain a catalyst.

[0049] The present invention does not particularly limit the molybdenum precursor and the nickel precursor. In one embodiment, the molybdenum precursor is ammonium molybdate, the nickel precursor is nickel nitrate, and the mass ratio of the impregnation solution to the carrier is 0.5-0.8:1.0. In the present invention, stirring can be performed once every period of time, for example, stirring once every 10-30 minutes, the drying temperature is, for example, 110-150°C, the drying time is, for example, 4-12 hours, the roasting temperature is, for example, 480-650°C, preferably 550-600°C, and the roasting time is, for example, 3-5h.

[0050] In one embodiment, the catalyst of the present invention further comprises a modification aid, wherein the modification aid is at least one of iron, cobalt and cerium. In another embodiment, the modification aid of the present invention is at least two of iron, cobalt and cerium.

[0051] In one embodiment, the carrier of the present invention is loaded with a modifying agent after loading the active component. The following is an exemplary method of loading the modifying agent after loading the active component: the carrier is impregnated with an active component impregnation solution, dried (not calcined), then impregnated with a modifying agent solution, dried, and calcined.

[0052] The modification aid solution is an aqueous solution of a modification aid precursor, wherein the concentration of the modification aid is, for example, 0.50-1.5 mol / L, the precursor of iron is, for example, an iron salt, such as iron nitrate, the precursor of cobalt is, for example, a cobalt salt, such as cobalt nitrate, and the precursor of cerium is, for example, a cerium salt, such as cerium nitrate. The mass ratio of the modification aid solution to the carrier is, for example, 0.5-0.8:1.0, and after impregnation, the catalyst is allowed to stand at room temperature for 8-12 hours, dried at 105-120°C for 3-5 hours, and calcined at 480-650°C, preferably 550-600°C, for 3-5 hours to obtain a catalyst.

[0053] In the catalyst of the present invention, the active components are calculated as molybdenum oxide and nickel oxide, the mass of the active components accounts for 10-30% of the mass of the carrier, preferably 20-25%, and the molybdenum: nickel molar ratio is 85-100:1, for example 87:1, 88:1, 89:1, 90:1, 92:1, 94:1, 95:1. In one embodiment, the carrier is modified with organosilicon, and the mass of the carrier is, for example, the mass of the carrier after the organosilicon modification.

[0054] In one embodiment, in the catalyst of the present invention, the modification aid, calculated as metal oxide, accounts for 0.3-0.7% of the mass of the catalyst.

[0055] The catalyst of the present invention is used to catalyze the hydrogenation and dehydration reaction of animal and vegetable oils to obtain C18 normal alkanes. In one embodiment, the animal and vegetable oils are non-edible vegetable oils and / or waste animal and vegetable oils, which can be directly purchased or obtained by refining the oils as raw materials. The purpose of refining the animal and vegetable oils is to remove impurities such as phosphorus, chlorine, and metals in the animal and vegetable oils.

[0056] In one embodiment, the hydrodehydration reaction is carried out in a fixed bed reactor at a reaction temperature of 320 to 400°C, preferably 350 to 380°C, a reaction pressure of 1 to 4 MPa, preferably 1.5 to 2.5 MPa, and a mass space velocity of 0.5 to 2 h -1 , preferably 0.8 to 1.5 hours -1 , the volume ratio of hydrogen to oil is 100-400:1, preferably 150-300:1.

[0057] In another embodiment, a solvent is further added to the hydrodehydration reaction, and the volume ratio of the solvent to the reaction mixture is 70-95%, preferably 75-90%, wherein the reaction mixture includes the reaction raw materials and the solvent. The present invention does not specifically limit the solvent, for example, it is n-octadecane or n-hexadecane or the hydrodeoxygenation product in this embodiment.

[0058] The mixture after the hydrogenation and dehydration reaction of the present invention can be firstly subjected to oil-water separation and then distilled to obtain C18 normal alkanes.

[0059] The catalyst of the invention is used for catalyzing the reaction of animal and plant fats and oils, and can avoid the occurrence of decarbonylation and decarboxylation side reactions during the reaction process, improve the selectivity of n-octadecane, and produce more n-octadecane. The selectivity of n-octadecane can be above 92.5%, reduce the subsequent separation pressure, and improve the purity of n-alkanes. The purity of n-alkanes is above 98.5%, and the impurity content is extremely low. The contents of sulfur, nitrogen, phosphorus and chlorine are all below 1 μg / g, the total metal content is below 3 μg / g, and aromatic hydrocarbons are not detected.

[0060] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0061] Nickel nitrate: Nickel nitrate hexahydrate, Aladdin reagent, AR, 98%

[0062] Molybdenum nitrate: Shanghai Yihe Biotechnology, AR, 99.95%

[0063] Magnesium nitrate: Magnesium nitrate hexahydrate, Tianjin Fuchen, 98%

[0064] Aluminum nitrate: Tianjin Fuchen, 99%

[0065] Citric acid: Jinan Century Tongda, 95%

[0066] Dodecyltrimethylammonium bromide: Aladdin reagent, AR, 98%

[0067] Ferric nitrate: Tianjin Fuchen, 98.5%

[0068] Cobalt nitrate: Guangzhou Deli Chemical, 98%

[0069] Cerium nitrate: Aladdin reagent, 99.5%

[0070] Tetraethoxysilane: Meril, 98%

[0071] Jatropha refined oil: Yunnan Shenyu

[0072] Castor oil refined oil: Yunnan Shenyu

[0073] Millennium Tung Oil: Yunnan Shenyu

[0074] Stearic acid: three-stage pressing, >99%, Zhongfu Oils and Fats Group Co., Ltd.

[0075] Carbon nanotubes: purity >95%, diameter 40-60nm, length 5-15μm, Shenzhen Nanoport Co., Ltd.

[0076] (1) Preparation of mixed alkanes

[0077] Refined animal and vegetable oils and fats are mixed with a solvent and reacted in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 320 to 400°C, preferably 350 to 380°C, a reaction pressure of 1 to 4 MPa, preferably 1.5 to 2.5 MPa, and a reaction mass space velocity of 0.5 to 2 h -1 , preferably 0.8 to 1.5 hours -1 The hydrogenation and dehydration reaction is carried out under the conditions of a hydrogen-to-oil volume ratio of 100 to 400:1, preferably 150 to 300:1, the solvent volume accounts for 70 to 95%, preferably 80 to 90%, and the hydrogenation and dehydration product is separated by water to obtain mixed alkanes. The mixed alkanes are analyzed by gas chromatography, and a HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected.

[0078] (2) Separation of mixed alkanes

[0079] A Fisher 2892 true boiling point apparatus was used under reduced pressure, with an operating pressure of 10 mmHg and a reflux ratio of 5 to separate normal alkanes from mixed alkanes.

[0080] Comparative Example 1

[0081] The carbon nanotubes were oxidized with nitric acid (concentration 6 mol / L) in an 80°C oil bath for 2 h, then filtered, washed with water until neutral, dried at 120°C, added to water, and dispersed with ultrasonic waves. 2 PdCl 4 The solution was stirred evenly and then formaldehyde solution was added. The pH value was adjusted to 9 with NaOH solution (1 mol / L). The mixture was stirred for 25 min, filtered, washed with water and dried to obtain a Pd / carbon nanotube catalyst.

[0082] According to the mass ratio, 2 parts of stearic acid, 0.5 parts of catalyst a, and 18 parts of n-hexane were added to a 100 ml reactor and filled with hydrogen (containing 20 μL / L NH 3 ), the initial hydrogen pressure was 6MPa, the mixture was stirred and heated, the reaction was stopped after 7h at 300℃, the catalyst and water were separated by filtration after cooling, the properties of the feedstock oil are shown in Table 1, the characteristics, evaluation conditions and evaluation results of the catalyst are shown in Table 2, the mixed alkanes were analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent was selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus was used, operated under reduced pressure, the operating pressure was 10mmHg, and the reflux ratio was 5, the mixed alkanes were separated into normal alkanes, and the purity of the separated normal alkanes is shown in Table 3.

[0083] Comparative Example 2

[0084] (1) First, take citric acid and dissolve it in water, then add magnesium nitrate, aluminum nitrate, and dodecyltrimethylammonium bromide in sequence. The molar ratio of magnesium nitrate, aluminum nitrate, dodecyltrimethylammonium bromide, citric acid, and water is 1:2:6:0.01:70. Stir for 2 to 3 hours at 80°C until the solution becomes a gel. Let it stand at room temperature for 1 hour, then put it in an oven for aging. Calcinate in a muffle furnace at 700°C, with a heating rate of 2 to 3°C / min, and calcine for 6 to 10 hours to obtain magnesium aluminum spinel.

[0085] Magnesium aluminum spinel powder, aluminum hydroxide dry glue, and sesbania powder were mixed evenly at a mass ratio of 8:2:0.3, and 0.8 mL / g MgAl 2 O 4 The catalyst carrier was prepared by dropping 4% dilute nitric acid into powder and then extruding it into strips. The catalyst carrier was calcined in a muffle furnace at 400°C for 6h to obtain the catalyst carrier.

[0086] (2) Weigh a certain amount of C in proportion 4 H 6 O 4 Ni·4H 2 O.Mo(NO 3 ) 3 ·5H 2 O, malic acid, the active component (Mo+Ni) is added in an amount of 20% of the carrier mass, calculated as the mass of MoO3+NiO, the molar ratio of Mo:Ni is 5, the molar ratio of (Mo+Ni):malic acid is 1.5:1, dissolved in deionized water, the mass ratio of the deionized water solution to the carrier is 0.7:1, the active component is loaded by an equal volume impregnation method, allowed to stand at 30°C for 10 h, dried at 110°C for 4 h in a muffle furnace and calcined at 600°C for 3.5 h to obtain the desired catalyst.

[0087] (3) Catalyst evaluation

[0088] Using n-octane solution containing 20% ​​tung oil by volume as raw material, a continuous fixed bed was used at a temperature of 370°C, a pressure of 2.0 MPa, and a space velocity of 1.0 h -1 , hydrogen to oil volume ratio of 200:1, the hydrodeoxygenation reaction was carried out, and the hydrodeoxygenation product was separated from water. The properties of the feedstock oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, and the mixed alkanes were analyzed by gas chromatography, using the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 true boiling point apparatus was used, operated under reduced pressure, with an operating pressure of 10mmHg and a reflux ratio of 5, to separate the mixed alkanes into normal alkanes, and the purity of the separated normal alkanes is shown in Table 3.

[0089] Example 1

[0090] (1) Preparation of carrier

[0091] First, take citric acid and dissolve it in water, then add magnesium nitrate, aluminum nitrate, and dodecyl trimethyl ammonium bromide in turn. The molar ratio of magnesium nitrate, aluminum nitrate, dodecyl trimethyl ammonium bromide, citric acid, and water is 1:2:6:0.01:70. Stir for 2 to 3 hours at 80°C until the solution becomes a gel. Let it stand at room temperature for 1 hour, then put it in an oven for aging. Calcinate in a muffle furnace at 700°C, with a heating rate of 2 to 3°C / min, and calcine for 6 to 10 hours to obtain magnesium aluminum spinel.

[0092] Magnesium aluminum spinel powder, aluminum hydroxide dry glue and sesbania powder were mixed evenly at a mass ratio of 6:1.2:0.2, and diluted nitric acid with a mass concentration of 2% was added at a liquid-solid ratio of 1.0 mL / g. Then, strips were extruded and calcined at 700° C. in a muffle furnace for 2 h to obtain a catalyst carrier.

[0093] (2) Carrier modification

[0094] Add tetraethoxysilane to water at a concentration of 0.005 g / ml. Use equal volume impregnation method to impregnate the catalyst support with the solution. After impregnation for 30 minutes, dry in an oven at 115°C for 12 hours.

[0095] (3) Active ingredient loading

[0096] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the carrier, the molybdenum: nickel molar ratio is 95; the mass ratio of the impregnation solution to the carrier is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0097] (4) Additive loading

[0098] A mixed solution of ferric nitrate + cobalt nitrate was prepared, the concentration of ferric nitrate was 0.5 mol / L, and the concentration of cobalt nitrate was 0.6 mol / L, and impregnated onto the catalyst carrier, the mass ratio of solution to carrier was 0.5:1. After impregnation, it was allowed to stand at room temperature for 10 h, dried in a muffle furnace at 110 °C for 4 h, and calcined at 600 °C for 4 h to obtain the desired catalyst.

[0099] (5) Catalyst evaluation

[0100] The refined Jatropha curcas oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of the above catalyst at a reaction temperature of 360°C, a reaction pressure of 1.0 MPa, and a reaction mass space velocity of 1.8 h -1 , the volume ratio of hydrogen to oil is 130:1, the volume of solvent accounts for 80% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0101] Example 2

[0102] (1) According to Example 1, a carrier was prepared.

[0103] (2) Carrier modification

[0104] Tetraethoxysilane was added to water at a concentration of 0.04 g / ml. The solution was impregnated onto the support using an equal volume impregnation method. After impregnation for 30 minutes, the support was dried at 120°C for 5 hours to obtain the final support.

[0105] (3) Active ingredient loading

[0106] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the carrier, the molybdenum: nickel molar ratio is 95; the mass ratio of the impregnation solution to the carrier is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0107] (4) Additive loading

[0108] A cerium nitrate solution was prepared with a concentration of 0.5 mol / L, and impregnated onto the catalyst carrier with a mass ratio of solution to carrier of 0.5:1. After impregnation, the solution was allowed to stand at room temperature for 10 h, dried at 110°C for 4 h in a muffle furnace, and calcined at 600°C for 4 h to obtain the desired catalyst.

[0109] (5) Catalyst evaluation

[0110] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 370°C, a reaction pressure of 4.0 MPa, and a reaction mass space velocity of 1.2 h -1 , the volume ratio of hydrogen to oil is 400:1, the volume of solvent accounts for 70% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0111] Example 3

[0112] (1) According to Example 1, a carrier was prepared.

[0113] (2) Carrier modification

[0114] Tetraethoxysilane was added to water at a concentration of 0.05 g / ml. The solution was impregnated onto the support using an equal volume impregnation method. After impregnation for 30 minutes, the support was dried at 120°C for 5 hours to obtain the final support.

[0115] (3) Active ingredient loading

[0116] First, nickel nitrate and molybdenum nitrate are prepared to obtain an impregnation solution, wherein the active component is MoO 3 The mass of +NiO is 20% of the mass of the carrier, the molar ratio of molybdenum to nickel is 100, and the mass ratio of the impregnation solution to the carrier is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0117] (4) Additive loading

[0118] A mixed solution of ferric nitrate + cobalt nitrate was prepared, the concentration of ferric nitrate was 0.7 mol / L, and the concentration of cobalt nitrate was 0.8 mol / L, and impregnated onto the catalyst carrier, the mass ratio of solution to carrier was 0.5:1. After impregnation, it was allowed to stand at room temperature for 10 h, dried in a muffle furnace at 110 °C for 4 h, and calcined at 600 °C for 4 h to obtain the desired catalyst.

[0119] (5) Catalyst evaluation

[0120] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 390°C, a reaction pressure of 3MPa, and a reaction mass space velocity of 2.0h -1 , the volume ratio of hydrogen to oil is 100:1, the volume of solvent accounts for 90%, the hydrogenation and dehydration products are separated by water, the properties of the feedstock oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0121] Example 4

[0122] (1) According to Example 1, a carrier was prepared.

[0123] (2) Carrier modification

[0124] Tetraethoxysilane was added to water at a concentration of 0.01 g / ml. The solution was impregnated onto the support using an equal volume impregnation method. After impregnation for 30 minutes, the support was dried at 120°C for 5 hours to obtain the final support.

[0125] (3) Active ingredient loading

[0126] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the carrier, the molybdenum: nickel molar ratio is 85; the mass ratio of the impregnation solution to the carrier is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0127] (4) Additive loading

[0128] A mixed solution of ferric nitrate + cerium nitrate was prepared, the concentration of ferric nitrate was 0.8 mol / L, the concentration of cerium nitrate was 0.5 mol / L, and it was impregnated onto the catalyst carrier. The mass ratio of the solution to the carrier was 0.5:1. After the impregnation was completed, it was allowed to stand at room temperature for 10 hours, dried in a muffle furnace at 110°C for 4 hours, and calcined at 600°C for 4 hours to obtain the desired catalyst.

[0129] (5) Catalyst evaluation

[0130] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 360°C, a reaction pressure of 1.5 MPa, and a reaction mass space velocity of 0.9 h -1 , the volume ratio of hydrogen to oil is 170:1, the volume of solvent accounts for 75% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0131] Example 5

[0132] (1) According to Example 4, the carrier preparation and carrier modification were carried out.

[0133] (2) Active ingredient loading

[0134] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the carrier, the molybdenum: nickel molar ratio is 90; the mass ratio of the impregnation solution to the carrier is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0135] (3) Additive loading

[0136] A mixed solution of ferric nitrate + cerium nitrate was prepared, the concentration of ferric nitrate was 1.0 mol / L, the concentration of cerium nitrate was 0.5 mol / L, and it was impregnated onto the catalyst carrier. The mass ratio of the solution to the carrier was 0.5:1. After the impregnation was completed, it was allowed to stand at room temperature for 10 hours, dried in a muffle furnace at 110°C for 4 hours, and calcined at 600°C for 4 hours to obtain the desired catalyst.

[0137] (4) Catalyst evaluation

[0138] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 370°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.0 h -1 , hydrogen-oil volume ratio 200:1, solvent volume ratio of reaction mixture 80%, hydrogenation dehydration product water separation, feed oil properties are shown in Table 1, catalyst characteristics, evaluation conditions and evaluation results are shown in Table 2, mixed alkanes are analyzed by gas chromatography, HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of mixed alkanes is shown in Table 3. Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, the reflux ratio is 5, and normal alkanes are separated from mixed alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0139] Example 6

[0140] Using the catalyst of Example 5, the refined tung oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 370°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.0 h -1 , hydrogen-oil volume ratio 200:1, solvent volume ratio of reaction mixture 80%, hydrogenation dehydration product water separation, feed oil properties are shown in Table 1, catalyst characteristics, evaluation conditions and evaluation results are shown in Table 2, mixed alkanes are analyzed by gas chromatography, HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of mixed alkanes is shown in Table 3. Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, the reflux ratio is 5, and normal alkanes are separated from mixed alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0141] Example 7

[0142] Using the catalyst of Example 5, castor oil refined oil was mixed with a solvent, and a hydrodehydration reaction was carried out in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 370° C., a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.0 h -1, the volume ratio of hydrogen to oil is 300:1, the volume of solvent accounts for 80% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0143] Example 8

[0144] (1) According to Example 1, a carrier was prepared.

[0145] (2) Carrier modification

[0146] Tetraethoxysilane was added to water at a concentration of 0.02 g / ml. The solution was impregnated onto the support using an equal volume impregnation method. After impregnation for 30 minutes, the support was dried at 120°C for 5 hours to obtain the final support.

[0147] (3) Active ingredient loading

[0148] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the support, the molybdenum: nickel molar ratio is 85, and the mass ratio of the impregnation solution to the support is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0149] (4) Additive loading

[0150] A mixed solution of ferric nitrate + cerium nitrate was prepared, the concentration of ferric nitrate was 0.6 mol / L, the concentration of cerium nitrate was 0.6 mol / L, and it was impregnated onto the catalyst carrier. The mass ratio of the solution to the carrier was 0.5:1. After the impregnation was completed, it was allowed to stand at room temperature for 10 hours, dried in a muffle furnace at 110°C for 4 hours, and calcined at 600°C for 4 hours to obtain the desired catalyst.

[0151] (5) Catalyst evaluation

[0152] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 355°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.1 h -1, the volume ratio of hydrogen to oil is 180:1, the volume of solvent accounts for 90% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0153] Example 9

[0154] Using the catalyst of Example 8, the refined tung oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 355°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.1 h / min. -1 , the volume ratio of hydrogen to oil is 180:1, the volume of solvent accounts for 90% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0155] Example 10

[0156] Using the catalyst of Example 8, castor oil refined oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 355°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.1 h -1 , the volume ratio of hydrogen to oil is 270:1, the volume of solvent accounts for 90% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0157] Embodiment 11

[0158] (1) According to Example 8, a carrier was prepared and modified.

[0159] (2) Active ingredient loading

[0160] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the support, the molybdenum: nickel molar ratio is 90, and the mass ratio of the impregnation solution to the support is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0161] (3) Additive loading

[0162] A mixed solution of ferric nitrate and cerium nitrate was prepared, with the concentration of ferric nitrate being 0.9 mol / L and the concentration of cerium nitrate being 0.6 mol / L. The solution was impregnated onto a catalyst carrier with a mass ratio of solution to carrier being 0.5:1. The solution was allowed to stand at room temperature for 10 h, dried in a muffle furnace at 110°C for 4 h, and calcined at 600°C for 4 h to obtain the desired catalyst.

[0163] (4) Catalyst evaluation

[0164] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 365°C, a reaction pressure of 2.5 MPa, and a reaction mass space velocity of 1.3 h -1 , the volume ratio of hydrogen to oil is 210:1, the volume of solvent accounts for 80% of the reaction mixture, the hydrodeoxygenation product is separated by water, the properties of the feedstock oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the normal alkanes are separated from the mixed alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0165] Example 12

[0166] Using the catalyst of Example 11, the refined tung oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 365°C, a reaction pressure of 2.5 MPa, and a reaction mass space velocity of 1.3 h -1, the volume ratio of hydrogen to oil is 210:1, the volume of solvent accounts for 80% of the reaction mixture, the hydrodeoxygenation product is separated by water, the properties of the feedstock oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the normal alkanes are separated from the mixed alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0167] Embodiment 13

[0168] Using the catalyst of Example 11, castor oil refined oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 365° C., a reaction pressure of 2.5 MPa, and a reaction mass space velocity of 1.3 h -1 , the volume ratio of hydrogen to oil is 290:1, the volume of solvent accounts for 80% of the reaction mixture, the hydrodeoxygenation product is separated by water, the properties of the feedstock oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0169] Embodiment 14

[0170] (1) According to Example 1, a carrier was prepared.

[0171] (2) Carrier modification

[0172] Tetraethoxysilane was added to water at a concentration of 0.01 g / ml. The solution was impregnated onto the support by an equal volume impregnation method. After impregnation for 30 minutes, the support was dried at 120°C for 5 hours to obtain the final support.

[0173] (3) Active component loading

[0174] First, molybdenum nitrate and nickel nitrate are dissolved in water to prepare an impregnation solution, in which the active component is MoO 3 The mass of +NiO is 20% of the mass of the support, the molybdenum: nickel molar ratio is 90, and the mass ratio of the impregnation solution to the support is 0.7: 1. After the impregnation is completed, it is allowed to stand at room temperature for 12 hours and dried in an oven at 115°C for 12 hours.

[0175] (4) Additive loading

[0176] A mixed solution of ferric nitrate + cerium nitrate was prepared, the concentration of ferric nitrate was 0.4 mol / L, the concentration of cerium nitrate was 1.0 mol / L, and it was impregnated onto the catalyst carrier. The mass ratio of the solution to the carrier was 0.5:1. After the impregnation was completed, it was allowed to stand at room temperature for 10 hours, dried in a muffle furnace at 110°C for 4 hours, and calcined at 600°C for 4 hours to obtain the desired catalyst.

[0177] (5) Catalyst evaluation

[0178] Jatropha curcas refined oil was mixed with a solvent and subjected to a hydrogenation dehydration reaction in a fixed bed reactor under the action of a hydrogenation deoxygenation catalyst at a reaction temperature of 380°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.4 h -1 , the volume ratio of hydrogen to oil is 180:1, the volume of solvent accounts for 85% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0179] Embodiment 15

[0180] Using the catalyst of Example 14, the refined tung oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 380°C, a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.4 h -1 , the volume ratio of hydrogen to oil is 180:1, the volume of solvent accounts for 85% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0181] Example 16

[0182] Using the catalyst of Example 14, castor oil refined oil was mixed with a solvent and subjected to a hydrodehydration reaction in a fixed bed reactor under the action of a hydrodeoxygenation catalyst at a reaction temperature of 380° C., a reaction pressure of 2.0 MPa, and a reaction mass space velocity of 1.4 h -1, the volume ratio of hydrogen to oil is 280:1, the volume of solvent accounts for 85% of the reaction mixture, the hydrogenation dehydration product is separated by water, the properties of the feed oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0183] Embodiment 17

[0184] (1) First, take citric acid and dissolve it in water, then add magnesium nitrate, aluminum nitrate, and dodecyltrimethylammonium bromide in sequence. The molar ratio of magnesium nitrate, aluminum nitrate, dodecyltrimethylammonium bromide, citric acid, and water is 1:2:6:0.01:70. Stir for 2 to 3 hours at 80°C until the solution becomes a gel. Let it stand at room temperature for 1 hour, then put it in an oven for aging. Calcinate in a muffle furnace at 700°C, with a heating rate of 2 to 3°C / min, and calcine for 6 to 10 hours to obtain magnesium aluminum spinel.

[0185] Magnesium aluminum spinel powder, aluminum hydroxide dry glue, and sesbania powder were mixed evenly at a mass ratio of 8:2:0.3, and the mixture was heated to 1.2 mL / g MgAl 2 O 4 The catalyst carrier was obtained by dropping 2% dilute nitric acid into powder and then extruding it into strips. The catalyst carrier was calcined in a muffle furnace at 800°C for 2h.

[0186] (2) Weigh a certain amount of NiSO according to the proportion 4 6H 2 O、(NH 4 ) 6 Mo 7 O 24 ·4H 2 O, glycolic acid, the amount of active component (Mo+Ni) added is MoO 3 The mass of +NiO is calculated as 20% of the mass of the carrier, the molar ratio of Mo:Ni is 90, the molar ratio of (Mo+Ni):glycolic acid is 0.3:1, dissolved in deionized water, the mass ratio of deionized water solution to the carrier is 0.7:1, the active component is loaded by equal volume impregnation method, left to stand at 20°C for 12h, dried in an oven at 110°C for 12h. Calcinated at 480°C for 5h to prepare the desired catalyst.

[0187] (3) Evaluation of catalyst

[0188] The evaluation raw materials and evaluation conditions are the same as those of Comparative Example 2. The properties of the raw oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0189] Embodiment 18

[0190] (1) First, take citric acid and dissolve it in water, then add magnesium nitrate, aluminum nitrate, and dodecyltrimethylammonium bromide in sequence. The molar ratio of magnesium nitrate, aluminum nitrate, dodecyltrimethylammonium bromide, citric acid, and water is 1:2:6:0.01:70. Stir for 2 to 3 hours at 80°C until the solution becomes a gel. Let it stand at room temperature for 1 hour, then put it in an oven for aging. Calcinate in a muffle furnace at 700°C, with a heating rate of 2 to 3°C / min, and calcine for 6 to 10 hours to obtain magnesium aluminum spinel.

[0191] Magnesium aluminum spinel powder, aluminum hydroxide dry glue, and sesbania powder were mixed evenly at a mass ratio of 8:2:0.3, and the mixture was heated to 1.2 mL / g MgAl 2 O 4 The catalyst carrier was obtained by dropping 2% dilute nitric acid into powder and then extruding it into strips. The catalyst carrier was calcined in a muffle furnace at 800°C for 2h.

[0192] (2) Weigh a certain amount of NiSO according to the proportion 4 6H 2 O、(NH 4 ) 6 Mo 7 O 24 ·4H 2 O, glycolic acid, the amount of active component (Mo+Ni) added is MoO 3 The mass of +NiO is calculated as 20% of the mass of the carrier, the molar ratio of Mo:Ni is 90, the molar ratio of (Mo+Ni):glycolic acid is 0.3:1, dissolved in deionized water, the mass ratio of deionized water solution to the carrier is 0.7:1, the active component is loaded by equal volume impregnation method, left to stand at 20°C for 12h, and dried in an oven at 110°C for 12h. The 1.5mol / L ferric nitrate solution is impregnated on the carrier loaded with the active component, the mass ratio of the solution to the carrier is 0.5:1, left to stand at 15°C for 10h, dried at 120°C for 3h and calcined at 480°C for 5h in a muffle furnace to prepare the desired catalyst.

[0193] (3) Evaluation of catalyst

[0194] The evaluation raw materials and evaluation conditions are the same as those of Comparative Example 2. The properties of the raw oil are shown in Table 1, the characteristics of the catalyst, the evaluation conditions and the evaluation results are shown in Table 2, the mixed alkanes are analyzed by gas chromatography, and the HP-1 capillary column (60m×0.25mm×1.00μm) produced by Agilent is selected, and the composition of the mixed alkanes is shown in Table 3. A Fisher 2892 real boiling point apparatus is used, operated under reduced pressure, the operating pressure is 10mmHg, and the reflux ratio is 5, and the mixed alkanes are separated into normal alkanes. The purity of the separated normal alkanes is shown in Table 3.

[0195] The calculation of the hydrodehydration rate takes Jatropha curcas refined oil as an example. In view of the fact that the total amount of C18 acid esters in Jatropha curcas oil is about 83.15ω%, and the total amount of C17 acid esters is about 0.02ω%, when calculating the hydrodehydration rate, the default value is C17 acid esters are zero, and the default value is zero for the C17 normal alkanes generated by the hydrogenation and dehydration of C17 acid esters. The C17 normal alkanes in the product are all generated by the decarbonylation and decarboxylation of C18 acid esters, that is:

[0196]

[0197] Table 1 Composition of crude oil

[0198]

[0199] Note: Lauric acid (C12:0) means lauric acid without carbon-carbon double bonds, linolenic acid (C18:3) means linolenic acid with three carbon-carbon double bonds, and the rest have similar meanings.

[0200]

[0201]

[0202]

[0203] As shown in Table 2-3, the higher the hydrogenation dehydration rate, the lower the probability of hydrogenation decarbonylation and decarboxylation side reactions, which means that the carbon chain end in the product breaks to generate CO. 2The less CO, the higher the content of C18 normal alkanes in the product. Improving the hydrodehydration rate and improving the yield of target product C16 and C18 normal alkanes are the purpose of the present invention. In comparative example 1, a catalyst loaded with precious metal Pd is used, intermittent reaction, the raw material is stearic acid, the raw material purity is high, the conversion rate is 98%, and the hydrodehydration selectivity is 95%. In comparative example 2, embodiment 17, and embodiment 18, a magnesium aluminum spinel catalyst loaded with non-precious metal molybdenum nickel is used, the molybdenum / nickel molar ratio is 5, 90, and 90 respectively (and the auxiliary agent is iron-modified), and the raw material is a complex tung oil refined oil. The hydrodehydration selectivity is gradually improved, and the highest is 91.8% (the molybdenum / nickel molar ratio is 90, and the auxiliary agent is iron-modified). It shows that the molybdenum / nickel molar ratio and auxiliary modification can improve the hydrodehydration rate to some extent. Therefore, in the examples, the molybdenum / nickel molar ratio, the type of additives (silicon, iron, cerium, cobalt), and the concentration of the additives were adjusted, and the hydrogenation dehydration rate was significantly improved. At the same time, the raw materials were expanded from tung oil refined oil to castor oil refined oil and tung oil refined oil. The evaluation results showed that the hydrogenation dehydration rate also met the requirements.

[0204] The method for preparing C18 normal alkanes from animal and plant oils provided by the present invention can control the occurrence of side reactions and improve the selectivity of target products by adjusting the molybdenum-nickel ratio in the catalyst and adding a modifying auxiliary agent. The obtained C18 normal alkanes have high purity and extremely low impurity contents such as sulfur and nitrogen aromatics, thereby avoiding the problems of complex production process and harsh process conditions in the production of normal alkanes from traditional fossil raw materials.

[0205] Therefore, the catalyst of the present invention uses magnesium aluminum spinel as a carrier, molybdenum and nickel as active components, and controls the molar ratio of molybdenum to nickel within the range of 85 to 100:1. The catalyst of the present invention is used to catalyze the hydrogenation and dehydration of animal and vegetable oils to generate normal alkanes with a conversion rate of 100%. Furthermore, by modifying the catalyst with iron, cobalt, and cerium modification additives, the selectivity of the target product C18 normal alkanes can be further improved, the decarbonylation and decarboxylation reactions can be reduced, the generation of by-products can be reduced, and at the same time, the content of the target product in the product is increased, which can reduce the subsequent separation pressure.

[0206] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing C18 normal alkanes from animal and vegetable oils and fats, characterized in that: The steps include: The animal and vegetable oils are subjected to a hydrogenation dehydration reaction under the action of a catalyst to obtain C18 normal alkanes; The catalyst comprises a carrier and an active component, wherein the carrier comprises magnesium aluminum spinel, and the active component comprises molybdenum and nickel, and the molar ratio of molybdenum to nickel is 85 to 100:

1.

2. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 1, characterized in that: The catalyst also includes a modification aid, and the modification aid is at least one of iron, cobalt and cerium.

3. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 1, characterized in that: The reaction temperature of the hydrodehydration reaction is 320-400°C, the reaction pressure is 1-4 MPa, and the mass space velocity is 0.5-2 h -1 , the volume ratio of hydrogen to oil is 100-400:

1.

4. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 1, characterized in that: A solvent is also added in the hydrogenation dehydration reaction, and the volume ratio of the solvent to the reaction mixture is 70-95%.

5. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 1, characterized in that: In the catalyst, the active components are calculated as molybdenum oxide and nickel oxide, and the mass of the active components accounts for 10-30% of the mass of the carrier.

6. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 2, characterized in that: The modification aid is calculated as metal oxide, and the modification aid accounts for 0.3-0.7% of the mass of the catalyst.

7. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 1, characterized in that: The preparation method of the catalyst comprises the following steps: Step 1, preparing magnesium aluminum spinel; Step 2, the magnesium aluminum spinel, aluminum hydroxide dry glue, and sesbania powder are mixed, an inorganic acid is added to extrudates, and calcined to obtain a carrier; Step 3, impregnating the carrier with a solution containing molybdenum and nickel active components to obtain a catalyst.

8. The method for preparing C18 normal alkanes from animal and vegetable fats according to claim 7, characterized in that: The method for preparing the magnesium-aluminum spinel comprises: mixing a magnesium source, an aluminum source, a complexing agent and citric acid, and calcining the mixture to obtain the magnesium-aluminum spinel.

9. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 8, characterized in that: Before the carrier is impregnated with the active component, the method further includes impregnating the carrier with an organic silicon solution.

10. The method for preparing C18 normal alkanes from animal and vegetable oils according to claim 7, characterized in that: The method for preparing the catalyst further comprises the steps of impregnating the catalyst obtained in step 3 with a solution containing a modification aid, and then drying and calcining.

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