Hydrodeoxygenation catalyst, method of making and use thereof in conversion of 1,4-cyclohexanedimethanol distillation light ends

Abstract

The application provides a hydrodeoxygenation catalyst, a preparation method and application of the hydrodeoxygenation catalyst in conversion of 1,4-cyclohexanedimethanol rectification light components, and the preparation method of the hydrodeoxygenation catalyst comprises the following steps: S1: dispersing a nickel source in a solvent to form a solution A1, dispersing a rare earth metal source and an aluminum source in a solvent to form a solution A2; preparing an alkaline solution B; S2: mixing the solution A1, the solution A2 and the alkaline solution B, performing a coprecipitation reaction to obtain a precipitate, and performing pyrolysis treatment on the precipitate to obtain the hydrodeoxygenation catalyst; and the hydrodeoxygenation catalyst provided by the application can be used to efficiently and environmentally protectively convert CHDM rectification light components, so as to obtain a liquid organic hydrogen carrier.

Description

Technical Field

[0001] This application relates to the field of catalytic chemistry technology, and in particular to a hydrodeoxygenation catalyst, its preparation method, and its application in the conversion of light components in the distillation of 1,4-cyclohexanediethanol. Background Technology

[0002] 1,4-Cyclohexanediethanol (CHDM) is an important chemical intermediate widely used in the synthesis of high-performance polyester materials, such as polycyclohexanediethanol terephthalate (PCT). Its excellent high-temperature resistance, chemical stability, and optical transparency make it irreplaceable in high-end fields such as baby products, medical devices, and special containers.

[0003] With the rapid growth in global demand for high-performance materials, the market size of CHDM continues to expand. However, CHDM production mainly involves the two-step hydrogenation of dimethyl terephthalate (DMT) and purification using a multi-tower distillation method. During the CHDM production process, a large amount of distilled light components (accounting for approximately 4-8% of CHDM production) are generated. These light components are primarily composed of oxygen-containing organic compounds with cyclohexyl structures (such as alcohols, ethers, and esters).

[0004] Currently, the main method for converting light components from CHDM distillation is incineration along with other organic waste liquids. This method is thorough and utilizes thermal energy, but it emits large amounts of CO2, VOCs, and other gases, failing to fully utilize carbon resources. Secondary distillation to separate and purify the organic matter is another method, but because the boiling points of the substances in the light components are close, the separation efficiency is low, making it difficult to obtain high-purity chemicals through simple distillation. Patent CN118047431A describes a treatment device for CHDM production wastewater, which uses a multi-unit high-voltage oxidizer (operating voltage 50~75kV) and an electromagnetic thermal oxidation processor (operating temperature 800~1000℃) to effectively degrade organic matter in the wastewater; however, the equipment cost and energy consumption are high.

[0005] Therefore, developing an efficient and environmentally friendly method for converting light components in CHDM distillation is an urgent technical problem that needs to be solved. Summary of the Invention

[0006] This application provides a hydrodeoxygenation catalyst, a preparation method, and its application in the conversion of light components in 1,4-cyclohexanediethanol distillation. Using the hydrodeoxygenation catalyst of this application, the light components of CHDM distillation can be converted efficiently and environmentally to obtain a liquid organic hydrogen carrier.

[0007] In a first aspect, this application provides a method for preparing a hydrodeoxygenation catalyst, comprising:

[0008] S1: Disperse the nickel source in a solvent to form solution A1, and disperse the rare earth metal source and aluminum source in a solvent to form solution A2; prepare alkaline solution B;

[0009] S2: Mix solutions A1 and A2 with alkaline solution B and carry out a co-precipitation reaction to obtain a precipitate. Then, pyrolyze the precipitate to obtain the hydrodeoxygenation catalyst.

[0010] In one possible implementation, the mixing steps of solution A1, solution A2 and alkaline solution B are as follows: solution A1, solution A2 and alkaline solution B are added dropwise to a container independently, the dropping speed is controlled, and the positions of solution A1, solution A2 and alkaline solution B in the container are different; stirring is performed simultaneously with the dropping, and the stirring speed is 50-100 r / min.

[0011] In one possible implementation, the ratio of the dropping rates of solution A1 and solution A2 is (0.5-2):1; the ratio of the sum of the dropping rates of solution A1 and solution A2 to the dropping rate of alkaline solution B is (0.5-2):1.

[0012] In one possible implementation, the mixing steps of solution A1, solution A2 and alkaline solution B are as follows: solution A1 and solution A2 are added dropwise along both sides of the container wall, and alkaline solution B is added dropwise in the center of the container.

[0013] In one possible implementation, in step S2, the atmosphere of the pyrolysis treatment is a mixture of hydrogen and nitrogen; in the mixture, the volume fraction of hydrogen is 10%-50%.

[0014] In one possible implementation, the nickel source includes at least one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O;

[0015] The rare earth metal source is at least one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, and Sc(NO3)3·4H2O;

[0016] The aluminum source is at least one of Al(NO3)3·9H2O, AlCl3·6H2O, and Al2(SO4)3·18H2O.

[0017] In one possible implementation, in step S2, the molar ratio of Ni:(M+Al) is (2-6):1, where M is a rare earth metal element; and the molar ratio of Al:M is (2-6):1.

[0018] In one possible implementation, the pyrolysis treatment temperature is 500-700°C, and the pyrolysis treatment time is 1-4 hours.

[0019] Secondly, this application provides a hydrodeoxygenation catalyst obtained according to the above preparation method.

[0020] Thirdly, this application provides a method for converting light fractions of 1,4-cyclohexanediethanol distillation into liquid organic hydrogen carriers using the above-mentioned hydrodeoxygenation catalyst, the method comprising:

[0021] The light fraction of 1,4-cyclohexanediethanol distillation and the aforementioned hydrodeoxygenation catalyst were mixed, and after being charged with hydrogen, the mixture was heated to obtain the liquid organic hydrogen carrier.

[0022] In one possible implementation, the mass of the hydrodeoxygenation catalyst is 5-20% of the mass of the light fraction of the 1,4-cyclohexanediethanol distillation.

[0023] And / or; the temperature of the heating reaction is 200-240℃;

[0024] And / or; the pressure of the hydrogen gas is 4-8 MPa;

[0025] And / or; the heating reaction time is 4-8 hours.

[0026] This application provides a hydrodeoxygenation catalyst, its preparation method, and its application in the conversion of light components in 1,4-cyclohexanediethanol distillation. Using this hydrodeoxygenation catalyst, the conversion of light components in CHDM distillation can be carried out efficiently and environmentally. Specifically, a hydrodeoxygenation catalyst with a hydrotalcite-like structure is efficiently prepared via a co-precipitation method. First, this application forms solutions of nickel and rare earth metal sources separately, controlling their addition positions to differ from those of the alkali solution. This facilitates the more convenient and uniform entry of the added rare earth metal elements into the hydrotalcite framework, resulting in more uniform dispersion of the metals. Second, through pyrolysis reduction, the evaporation of crystal water and the continuous generation of gases from the decomposition of hydrotalcite allow gases to escape from the catalyst interior, forming more channels within the catalyst and maintaining a layered structure, thereby increasing the catalyst's specific surface area and pore size. Finally, during pyrolysis, the metal elements are transformed into metal oxides. NiO is further reduced by hydrogen to generate metallic Ni nanoparticles. These nanoparticles attract high-valence rare earth elements through interfacial oxygen vacancies and electron transfer to achieve charge balance, inducing partial migration of rare earth oxides and enrichment around the Ni particles. The Lewis acidic sites on the surface of the rare earth oxides bind to the Ni particles, enhancing the interaction between them and Ni. This helps to fix the Ni particles, reduce surface energy, and reduce the aggregation of metallic Ni at high temperatures. At the same time, it also enhances electron transfer between Ni and Ni, improving the adsorption and dissociation capacity of hydrogen. The oxygen vacancies formed by the oxides themselves enhance the adsorption capacity of oxygen-containing functional groups of the substrate, thus improving the catalyst's hydrogenation and deoxygenation capabilities. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 TEM image of the hydrodeoxygenation catalyst of Example 1 provided in this application;

[0029] Figure 2 Provided for this application Figure 1 A magnified view of a portion of the image;

[0030] Figure 3 Provided for this application Figure 1 A magnified view of the area within the red box.

[0031] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, this application will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the invention and are not intended to limit its scope. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. When the following description relates to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0033] In a first aspect, this application provides a method for preparing a hydrodeoxygenation catalyst, comprising:

[0034] S1: Disperse the nickel source in a solvent to form solution A1, and disperse the rare earth metal source and aluminum source in a solvent to form solution A2; prepare alkaline solution B;

[0035] S2: Mix solutions A1 and A2 with alkaline solution B and carry out a co-precipitation reaction to obtain a precipitate. Then, pyrolyze the precipitate to obtain a hydrodeoxygenation catalyst.

[0036] The hydrodeoxygenation catalyst of this application enables efficient and environmentally friendly conversion of light components in CHDM distillation. Specifically, a hydrodeoxygenation catalyst with a hydrotalcite-like structure is efficiently prepared via co-precipitation. First, this application separately prepares solutions of nickel and rare earth metal sources, controlling their addition locations to differ from the alkali solution. This facilitates more convenient and uniform entry of the added rare earth metal elements into the hydrotalcite framework, resulting in more uniform metal dispersion. Second, through pyrolysis and reduction, the evaporation of water of crystallization and the continuous generation of gases from the decomposition of hydrotalcite allow gases to escape from the catalyst interior, forming more channels and maintaining the lamellar structure, thereby increasing the catalyst's specific surface area and pore size. Finally, during pyrolysis, the metal elements are transformed into metal oxides. NiO is further reduced by hydrogen to generate metallic Ni nanoparticles. These nanoparticles attract high-valence rare earth elements through interfacial oxygen vacancies and electron transfer to achieve charge balance, inducing partial migration of rare earth oxides and enrichment around the Ni particles. The Lewis acidic sites on the surface of the rare earth oxides bind to the Ni particles, enhancing the interaction between them and Ni. This can fix the Ni particles, reduce surface energy, and reduce the aggregation of metallic Ni at high temperatures. At the same time, it also enhances electron transfer with Ni, improving the adsorption and dissociation capacity of hydrogen. The oxygen vacancies formed by the oxides themselves can enhance the adsorption capacity of oxygen-containing functional groups of the substrate, thus improving the catalyst's hydrogenation and deoxygenation capabilities.

[0037] In one possible implementation, the mixing steps of solution A1, solution A2 and alkaline solution B are as follows: solution A1, solution A2 and alkaline solution B are added dropwise to the container independently, the dropping speed is controlled, and the dropwise positions of solution A1, solution A2 and alkaline solution B in the container are different; stirring is carried out at the same time as dropping, and the stirring speed is 50-100 r / min.

[0038] This application controls the different dropwise positions of solutions A1, A2, and alkaline solution B in the solution, creating a buffer zone between each metal element and alkaline solution B. This controls the rate of precipitation formation, making the precipitation reaction more stable and preventing metals that easily form precipitates from rapidly nucleating while other metals fail to enter the hydrotalcite framework. Therefore, the distribution of each element in the hydrotalcite is more uniform. Furthermore, because the different dropwise positions of solutions A1, A2, and B require simultaneous stirring at a speed of 50-100 r / min (i.e., a relatively slow stirring rate), the precipitation reaction is prevented from becoming too slow.

[0039] In one possible implementation, the ratio of the dropping rates of solution A1 to solution A2 is (0.5-2):1; the ratio of the sum of the dropping rates of solution A1 and solution A2 to the dropping rate of alkaline solution B is (0.5-2):1.

[0040] It is understandable that the dropping rate ratio of solution A1 and solution A2 is (0.5-2):1, for example, 0.5:1, 1.0:1, 1.5:1, 2.0:1 or any value between two of them.

[0041] It is understandable that the ratio of the sum of the dropping rates of solutions A1 and A2 to the dropping rate of alkaline solution B is (0.5-2):1, for example, 0.5:1, 1.0:1, 1.5:1, 2.0:1 or any value between two of these.

[0042] In one possible implementation, the mixing steps of solutions A1, A2, and alkaline solution B are as follows: solutions A1 and A2 are added dropwise along both sides of the container wall, while alkaline solution B is added dropwise to the center of the container. This arrangement creates a buffer zone between the metal elements and alkaline solution B, controlling the rate of precipitation and making the precipitation reaction more stable.

[0043] In one possible implementation, in step S2, the atmosphere for the pyrolysis treatment is a mixture of hydrogen and nitrogen; in the mixture, the volume fraction of hydrogen is 10%-50%.

[0044] This application selects a mixed atmosphere of hydrogen and nitrogen for pyrolysis and reduction under an H2 / N2 atmosphere. The generated gas enables the catalyst to form more channels and maintain its lamellar structure, increasing the specific surface area and pore size of the catalyst. Ni is reduced to form metal particles, and rare earth elements partially migrate and accumulate around the Ni particles, enhancing the interaction between them and Ni. This helps to fix the Ni particles and reduce metal agglomeration. At the same time, it also enhances electron transfer between Ni and Ni, improving the adsorption and dissociation capacity of hydrogen. The oxygen vacancies formed by the catalyst itself can enhance the adsorption capacity of oxygen-containing functional groups of the substrate, thus improving the catalyst's hydrogenation and deoxygenation capacity.

[0045] Understandably, in the mixed atmosphere, the volume fraction of hydrogen is 10%-50%, for example, 10%, 20%, 30%, 40%, 50%, or any value between two of these.

[0046] In one possible implementation, the nickel source includes at least one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O;

[0047] The rare earth metal source is at least one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, and Sc(NO3)3·4H2O;

[0048] The aluminum source is at least one of Al(NO3)3·9H2O, AlCl3·6H2O, and Al2(SO4)3·18H2O.

[0049] In one possible implementation, in step S2, the molar ratio of Ni:(M+Al) is (2-6):1, where M is a rare earth metal element; and the molar ratio of Al:M is (2-6):1.

[0050] In this application, the molar ratio of Ni:(M+Al) is set to (2-6):1, preferably 4-6:1.

[0051] It is understandable that the molar ratio of Ni:(M+Al) is (2-6):1, for example 2:1, 3:1, 4:1, 5:1, 6:1 or any value between two of these.

[0052] It is understandable that the molar ratio of Al:M is (2-6):1, for example 2:1, 3:1, 4:1, 5:1, 6:1 or any value between two of these.

[0053] In one possible implementation, the molar ratio of Al:M is (2-4):1.

[0054] In one possible implementation, the pyrolysis treatment temperature is 500-700°C, and the pyrolysis treatment time is 1-4 hours.

[0055] At the above pyrolysis temperature, hydrotalcite is completely decomposed into metal oxides, while Ni is reduced to metallic Ni.

[0056] It is understood that the pyrolysis treatment temperature is 500-700℃, for example, 500℃, 550℃, 600℃, 650℃, 700℃ or any two of these ranges.

[0057] It is understandable that the pyrolysis treatment time is 1-4 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours or any two of these ranges.

[0058] In one possible implementation, the pyrolysis treatment temperature is 500-600℃ and the pyrolysis treatment time is 2-3 hours.

[0059] In one possible implementation, alkaline solution B comprises sodium carbonate and sodium hydroxide.

[0060] In one possible implementation, the molar ratio of the metal precursor to Na2CO3 is (1.0-4.0):1, preferably 2:1; the molar ratio of the metal precursor to NaOH is (0.2-1.0):1, preferably 0.5:1, wherein the molar amount of the metal precursor is the sum of the molar amounts of nickel, rare earth metals and aluminum.

[0061] It is understandable that the molar ratio of the metal precursor to Na2CO3 is (1.0-4.0):1, for example, 1.0:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1 or any value between two of these.

[0062] It is understandable that the molar ratio of the metal precursor to NaOH is (0.2-1.0):1, for example, 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1.0:1 or any value between two of these.

[0063] In one possible implementation, in step S2, solution A1, solution A2 and alkaline solution B are mixed and stirred at room temperature for 2 to 6 hours, preferably 3 to 4 hours.

[0064] It is understandable that the stirring time is 2 to 6 hours, for example, 2 hours, 4 hours, 6 hours or any two of these ranges.

[0065] Secondly, this application provides a hydrodeoxygenation catalyst obtained according to the above preparation method.

[0066] Thirdly, this application provides a method for converting light fractions of 1,4-cyclohexanediethanol distillation into liquid organic hydrogen carriers using the above-mentioned hydrodeoxygenation catalyst, comprising:

[0067] The light fraction of 1,4-cyclohexanediethanol distillation was mixed with a hydrodeoxygenation catalyst, and after being charged with hydrogen, the mixture was heated to produce a liquid organic hydrogen carrier.

[0068] Based on the chemical structure of the light fraction of 1,4-cyclohexanediethanol distillation, this application has discovered a liquid organic hydrogen carrier that can be converted into cyclohexanes through a hydrodeoxygenation reaction (one of the most widely used systems at present), thus realizing the simple and high-value utilization of the light fraction of 1,4-cyclohexanediethanol distillation.

[0069] This application utilizes a hydrodeoxygenation catalyst to prepare a liquid organic hydrogen support from the light fraction of 1,4-cyclohexanediethanol distillation. In this process, oxygen-containing functional groups in the distilled light fraction preferentially adsorb onto oxygen vacancies on the catalyst. Simultaneously, H2 is activated on metallic Ni, attacking the oxygen-containing functional groups and cleaving the CO bond to generate homologues of cyclohexane, which can serve as liquid organic hydrogen supports. After the reaction is complete, only water needs to be added to the reaction system. Since the cyclohexane homologues are insoluble in water, they will automatically separate into layers, allowing for rapid separation of the liquid organic hydrogen support. The remaining alcohol-water solution can be further separated and utilized or processed.

[0070] In one possible implementation, the mass of the hydrodeoxygenation catalyst is 5-20% of the mass of the light component of the 1,4-cyclohexanediethanol distillation.

[0071] Understandably, the mass of the hydrodeoxygenation catalyst is 5-20% of the mass of the light component of the 1,4-cyclohexanediethanol distillation, for example, 5%, 8%, 10%, 12%, 15%, 18%, 20%, or any two of these values.

[0072] In one possible implementation, the temperature of the heating reaction is 200-240°C.

[0073] It is understood that the temperature of the heating reaction is 200-240℃, such as 200℃, 220℃, 240℃ or any two of these values.

[0074] In one possible implementation, the hydrogen gas pressure is 4-8 MPa.

[0075] It is understandable that the pressure of hydrogen gas is 4-8 MPa, for example, 4 MPa, 6 MPa, 8 MPa or any two of these ranges.

[0076] In one possible implementation, the heating reaction takes 4-8 hours.

[0077] Understandably, the heating reaction time is 4-8 hours, for example, 4 hours, 6 hours, 8 hours, or any value in between.

[0078] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0079] Example 1

[0080] This embodiment provides a Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalyst is prepared with a Ni:La:Al molar ratio of 4:0.2:0.8, i.e., a Ni:(La+Al) molar ratio of 4:1 and an Al:La molar ratio of 4:1. The specific preparation method is as follows:

[0081] S1: Dissolve 21.81g of Ni(NO3)2·6H2O in 250mL of water, and record it as solution A1; dissolve 5.63g of Al(NO3)3·9H2O and 1.62g of La(NO3)3·6H2O in 250mL of water, and record it as solution A2.

[0082] S2: Dissolve 4.97g of Na2CO3 and 7.50g of NaOH in 500mL of water, and this is called alkaline solution B.

[0083] S3: Using a peristaltic pump, add solutions A1 and A2 dropwise along both sides of the beaker wall at the same rate (1:1), both 5.0 mL / min. Simultaneously, add alkaline solution B from the center of the beaker at a rate of 10.0 mL / min. Stir continuously to ensure the solutions are mixed evenly (stirring speed 70 r / min). The final molar ratio of Ni:La:Al in the beaker is 4:0.2:0.8, and the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to Na2CO3 is 2:1; the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to NaOH is 0.5:1.

[0084] S4: After the addition is complete, continue stirring the mixture at room temperature for 4 hours; then filter the turbid liquid and wash it with water until the pH of the filtrate is 7.

[0085] S5: The product obtained in S4 was dried in an 80℃ oven for 6 hours, then transferred to a tube furnace and heated to 600℃ at a rate of 5℃ / min in an H2 / N2 atmosphere with a hydrogen volume fraction of 10% for 2 hours to obtain Ni. 4.0 / La 0.2 Al 0.8 O 1.5 catalyst.

[0086] Figure 1 This is a transmission electron microscope (TEM) image of the catalyst corresponding to Example 1. Figure 2 for Figure 1 Enlarged layout view Figure 3 for Figure 1 A magnified view of the area within the red box. (From...) Figure 1-3 It can be seen that the Ni metal particles are uniformly dispersed in the catalyst, and a thin La2O3 layer is attached to the surface of the particles.

[0087] Example 2

[0088] The preparation method is the same as in Example 1, except that the amount of Ni(NO3)2·6H2O added is 10.91 g, 32.74 g, and 43.62 g, respectively, and the resulting catalysts are labeled as Ni 2.0 / La 0.2 Al 0.8 O 1.5 Ni 6.0 / La 0.2 Al 0.8 O 1.5 and Ni 8.0 / La 0.2 Al 0.8O 1.5 .

[0089] Example 3

[0090] The preparation method is the same as in Example 1, except that the masses of La(NO3)3·6H2O and Al(NO3)3·9H2O are 2.44g and 4.92g, 2.03g and 5.27g, and 1.22g and 5.98g, respectively, and the resulting catalysts are labeled as Ni. 4.0 / La 0.3 Al 0.7 O 1.5 Ni 4.0 / La 0.25 Al 0.75 O 1.5 and Ni 4.0 / La 0.15 Al 0.85 O 1.5 .

[0091] Example 4

[0092] The preparation method is the same as in Example 1, except that 1.62 g of La(NO3)3·6H2O is replaced with 1.63 g of Ce(NO3)3·6H2O, and 1.13 g of Sc(NO3)3·4H2O are used. The resulting catalysts are labeled as Ni. 4.0 / Ce 0.2 Al 0.8 O 1.5 Ni 4.0 / Sc 0.2 Al 0.8 O 1.5 .

[0093] Example 5

[0094] This embodiment provides a Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalyst is prepared with a Ni:La:Al molar ratio of 4:0.2:0.8, i.e., a Ni:(La+Al) molar ratio of 4:1 and an Al:La molar ratio of 4:1. The specific preparation method is as follows:

[0095] S1: Dissolve 21.81g of Ni(NO3)2·6H2O in 125mL of water, and record it as solution A1; dissolve 5.63g of Al(NO3)3·9H2O and 1.62g of La(NO3)3·6H2O in 250mL of water, and record it as solution A2.

[0096] S2: Dissolve 4.97g of Na2CO3 and 7.50g of NaOH in 750mL of water, and this is called alkaline solution B.

[0097] S3: Using a peristaltic pump, add solutions A1 and A2 dropwise along both sides of the beaker wall at a rate of 2.5 mL / min for A1 and 5.0 mL / min for A2. Simultaneously, add alkaline solution B from the center of the beaker at a rate of 15.0 mL / min. Stir continuously to ensure uniform mixing (stirring speed 50 r / min). The final molar ratio of Ni:La:Al in the beaker should be 4:0.2:0.8, and the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to Na2CO3 should be 2:1; the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to NaOH should be 0.5:1.

[0098] S4: After the addition is complete, continue stirring the mixture at room temperature for 4 hours; then filter the turbid liquid and wash it with water until the pH of the filtrate is 7.

[0099] S5: The product obtained in S4 was dried in an 80℃ oven for 6 hours, then transferred to a tube furnace and heated to 500℃ at a rate of 5℃ / min in an H2 / N2 atmosphere with a hydrogen volume fraction of 50%. After treatment for 2 hours, the catalyst was obtained.

[0100] Example 6

[0101] This embodiment provides a Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalyst is prepared with a Ni:La:Al molar ratio of 4:0.2:0.8, i.e., a Ni:(La+Al) molar ratio of 4:1 and an Al:La molar ratio of 4:1. The specific preparation method is as follows:

[0102] S1: Dissolve 21.81g of Ni(NO3)2·6H2O in 500mL of water, and record it as solution A1; dissolve 5.63g of Al(NO3)3·9H2O and 1.62g of La(NO3)3·6H2O in 250mL of water, and record it as solution A2.

[0103] S2: Dissolve 4.97g of Na2CO3 and 7.50g of NaOH in 375mL of water, and denote this as alkaline solution B.

[0104] S3: Using a peristaltic pump, add solutions A1 and A2 dropwise along both sides of the beaker wall at a rate of 10 mL / min for A1 and 5.0 mL / min for A2. Simultaneously, add alkaline solution B from the center of the beaker at a rate of 7.5 mL / min. Stir continuously to ensure uniform mixing (stirring speed 100 r / min). The final molar ratio of Ni:La:Al in the beaker should be 4:0.2:0.8, and the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to Na2CO3 should be 2:1; the molar ratio of the metal precursor (the sum of the molar amounts of Ni, La, and Al) to NaOH should be 0.5:1.

[0105] S4: After the addition is complete, continue stirring the mixture at room temperature for 4 hours; then filter the turbid liquid and wash it with water until the pH of the filtrate is 7.

[0106] S5: The product obtained in S4 was dried in an 80℃ oven for 6 hours, then transferred to a tube furnace and heated to 700℃ at a rate of 5℃ / min in an H2 / N2 atmosphere with a hydrogen volume fraction of 10%. After treatment for 2 hours, the catalyst was obtained.

[0107] Example 7

[0108] The only difference between this embodiment and Embodiment 1 is that the solutions A1 and A2 in S1-S3 and the alkaline solution B are added at the same position, all in the center of the beaker.

[0109] Comparative Example 1

[0110] The only difference between this comparative example and Example 1 is that Ni(NO3)2·6H2O, Al(NO3)3·9H2O, La(NO3)3·6H2O, NaOH and Na2CO3 are directly dissolved together in 1000mL of water.

[0111] Application Example 1

[0112] Weigh 0.5g of the catalyst prepared in Example 1 and Example 2 and 10g of the light component of CHDM distillation, respectively, and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. After the temperature rises to 220°C, start stirring and start timing. The reaction time is 4h. After the reaction is completed, cool the reaction system to room temperature.

[0113] The mass percentages of the light components in the CHDM distillation are as follows: 35% 4-(methoxymethyl)cyclohexanemethanol, 32% 4-methyl-1-cyclohexanemethanol, 15% 1,4-cyclohexanediethanol, 10% 4-(hydroxymethyl)cyclohexanecarboxylate, 5% 1,4-cyclohexanedicarboxylate, and 3% cyclohexanemethanol.

[0114] After the reaction is complete, water is added to the reaction system. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers, and liquid organic hydrogen carriers can be quickly obtained by separation.

[0115] In addition, 3 mL of the reaction solution from the reaction system after the reaction was completed was diluted with 30 mL of dioxane, and the composition of the reaction solution was analyzed by gas chromatography. The gas chromatograph was equipped with a 30 μm capillary column (HP-5MS, USA) and a flame ionization detector. The reaction results using catalysts with different nickel contents are shown in Table 1 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0116] Conversion rate of the light component = (1 - molar amount of cyclohexyl in the oxygen-containing substance after reaction / molar amount of cyclohexyl in the added light component) × 100%;

[0117] Product selectivity = (molar amount of the corresponding product generated / molar amount of cyclohexyl in the added light component) × conversion rate of the light component.

[0118] Table 1

[0119]

[0120] Table 1 shows the reaction results using catalysts with different Ni contents. As can be seen from Table 1, when the Ni content is moderate, the Ni particles are uniformly dispersed and the hydrodeoxygenation effect is good; when the Ni content is low, the hydrogenation active sites decrease and the conversion rate decreases; when the Ni content is too high, particle agglomeration is likely to occur, and the hydrodeoxygenation effect decreases.

[0121] Application Example 2

[0122] Weigh out 0.5g of the catalyst prepared in Examples 1 and 3, and 10g of CHDM distillation light fraction (the same CHDM distillation light fraction as in Application Example 1), and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature and add water. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0123] In addition, 3 mL of the reaction solution from the reaction system after the reaction was completed was diluted with 30 mL of dioxane, and the analytical method was the same as in Application Example 1. The effect of using different Al:La molar ratios on the catalytic effect is shown in Table 2 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0124] Table 2

[0125]

[0126] Table 2 shows the effect of different Al:La molar ratios on the catalytic effect. As can be seen from Table 2, when the Al:La molar ratio is too high, the conversion rate decreases slightly, and the CYH selectivity increases significantly. This may be because the Ni-La interaction decreases, the preferential adsorption of oxygen-containing functional groups in the substrate weakens, and Al2O3 is more acidic, easily leading to CC breakage. Increasing the La content improves the catalytic effect but increases the catalyst cost.

[0127] Application Example 3

[0128] Weigh out 0.5 g of the catalyst prepared in Examples 1 and 4, and 10 g of the CHDM distillation light component (the same light component as in Example 1), and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature and add water. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0129] In addition, 3 mL of the reaction solution from the reaction system after the reaction was completed was diluted with 30 mL of dioxane, and the analytical method was the same as in Application Example 1. The effect of different rare earth metal ratios on the catalytic effect is shown in Table 3 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0130] Table 3

[0131]

[0132] Table 3 shows the effect of different rare earth metals on the catalytic effect. As can be seen from Table 3, the addition of three rare earth metals resulted in excellent catalyst performance. Ni 4.0 / La 0.2 Al 0.8 O 1.5 The optimal activity of La is likely due to the stronger interaction between La and Ni, which better promotes the dispersion of Ni.

[0133] Application Example 4

[0134] Weigh 0.5 g of the catalyst prepared in Example 1 and 10 g of the light component of CHDM distillation, and place them in a high-pressure reactor (the light component of distillation is the same as in Example 1). After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature rises to 160-240°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature and add water to the reaction system. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0135] In addition, take 3 mL of the reaction solution from the reaction system after the reaction is completed, add 30 mL of dioxane to dilute, and analyze using the same method as in Application Example 1. Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalytic effects at different reaction temperatures are shown in Table 4 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0136] Table 4

[0137]

[0138] Table 4 shows the effect of different reaction temperatures on the catalytic effect. As can be seen from Table 4, when the reaction temperature is low, the catalyst's hydrogenation and deoxygenation capacity is insufficient, resulting in a low conversion rate.

[0139] Application Example 5

[0140] Weigh 0.5 g of the catalyst prepared in Example 1 and 10 g of the CHDM distillation light component (the same light component as in Example 1), and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 2-8 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature and add water. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0141] In addition, take 3 mL of the reaction solution from the reaction system after the reaction is completed, add 30 mL of dioxane to dilute, and analyze using the same method as in Application Example 1. Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalytic effects under different hydrogen pressures are shown in Table 5 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0142] Table 5

[0143]

[0144] Table 5 shows the effect of different hydrogen pressures on the catalytic effect. As can be seen from Table 5, when the hydrogen pressure is low, the hydrogenation deoxygenation rate is slow, the conversion rate is low, and there is less CC breakage.

[0145] Application Example 6

[0146] Weigh 0.5 g of the catalyst prepared in Example 1 and 10 g of the CHDM distillation light component (the same light component as in Example 1), and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 2–8 hours. After the reaction is complete, cool the reaction system to room temperature and add water. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0147] In addition, take 3 mL of the reaction solution from the reaction system after the reaction is completed, add 30 mL of dioxane to dilute, and analyze using the same method as in Application Example 1. Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalytic effects at different reaction times are shown in Table 6 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0148] Table 6

[0149]

[0150] Table 6 shows the catalytic effect at different reaction times. As can be seen from Table 6, the enhanced deoxygenation reaction can be basically completed within 4 hours.

[0151] Application Example 7

[0152] Weigh 0.2-2 g of the catalyst prepared in Example 1 and 10 g of the CHDM distillation light component (the same light component as in Example 1), place them in a high-pressure reactor, replace the gas in the reactor with hydrogen five times, and then pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer, and start stirring and timing after the temperature rises to 220°C. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature, add water to the reaction system. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers, and liquid organic hydrogen carriers can be quickly obtained by separation.

[0153] Additionally, 3 mL of the reaction solution from the reaction system after the reaction was completed was diluted with 30 mL of dioxane, and the analytical method was the same as in Application Example 1. In different Ni...4.0 / La 0.2 Al 0.8 O 1.5 The catalytic effects at different catalyst dosages are shown in Table 7 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0154] Table 7

[0155]

[0156] Table 7 shows the effect of different catalyst dosages on the catalytic effect. As can be seen from Table 7, Ni... 4.0 / La 0.2 Al 0.8 O 1.5 The catalyst exhibits excellent hydrodeoxygenation activity, and a dosage of 5% is sufficient to achieve good results.

[0157] Application Example 8

[0158] Weigh 0.5 g of the catalyst prepared in Example 1 and 10 g of CHDM distillation light fraction (the same light fraction as in Example 1), and place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature and add water. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0159] Additionally, 3 mL of the reaction solution from the reaction system after the reaction was completed was diluted with 30 mL of dioxane, and the analytical method was the same as in Application Example 1. The recovered catalyst was used for the next recycling reaction. Recycled Ni 4.0 / La 0.2 Al 0.8 O 1.5 The catalytic effects are shown in Table 8 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0160] Table 8

[0161]

[0162] Table 8 shows Ni 4.0 / La 0.2 Al 0.8 O 1.5 The effect of catalyst recycling is shown in Table 8. The Ni prepared in this application... 4.0 / La 0.2 Al 0.8 O1.5 The catalyst exhibits good stability. After five cycles of use, the catalyst activity did not decrease significantly. This is mainly due to the uniform dispersion of the metal caused by the hydrotalcite-like precursor. After pyrolysis and reduction, the interaction between different components is enhanced. In particular, La migrates to the vicinity of Ni particles, hindering the aggregation of Ni particles, thereby improving the metal dispersion and stability.

[0163] Application Example 9

[0164] Weigh out 0.5 g each of the catalysts prepared in Examples 1, 5, 6, 7, and Comparative Example 1, and 10 g of CHDM distillation light fraction (the same light fraction as in Application Example 1). Place them in a high-pressure reactor. After replacing the gas in the reactor with hydrogen five times, pressurize the reactor to 4 MPa. Place the high-pressure reactor in an electrically heated magnetic stirrer. Once the temperature reaches 220°C, start stirring and begin timing. The reaction time is 4 hours. After the reaction is complete, cool the reaction system to room temperature. Add water to the reaction system. Since the homologues of cyclohexane are insoluble in water, they will automatically separate into layers. Liquid organic hydrogen carriers can be quickly obtained by liquid-liquid separation.

[0165] In addition, 3 mL of the reaction solution in the reaction system after the reaction was completed was diluted with 30 mL of dioxane. The analytical method was the same as in Application Example 1. The effect of catalytic effect is shown in Table 9 (CYH is cyclohexane, MCH is methylcyclohexane, and DMCH is 1,4-dimethylcyclohexane).

[0166] Table 9

[0167]

[0168] Table 9 shows the effects of catalysts prepared by different methods. As can be seen from Table 9, catalysts prepared when solutions A1, A2, and alkaline solution B are added at different positions in the container exhibit excellent effects. However, when the addition positions are the same, the hydrogenation and deoxygenation capabilities of the prepared catalysts are slightly weaker. The catalyst prepared by directly dissolving the metal precursors, NaOH, and Na2CO3 in water has the worst effect. This is because each metal precursor readily nucleates and forms precipitates, resulting in uneven distribution of metal elements within the hydrotalcite framework or some metals failing to enter the framework, thus degrading the catalyst's effectiveness.

[0169] Finally, it should be noted that other embodiments of the invention will be readily apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings. Various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for preparing a hydrodeoxygenation catalyst, characterized in that, include: S1: Disperse the nickel source in a solvent to form solution A1, and disperse the rare earth metal source and aluminum source in a solvent to form solution A2; prepare alkaline solution B; S2: Mix solutions A1 and A2 with alkaline solution B and carry out a co-precipitation reaction to obtain a precipitate. Then, pyrolyze the precipitate to obtain the hydrodeoxygenation catalyst.

2. The preparation method according to claim 1, characterized in that, The mixing steps of solution A1, solution A2 and alkaline solution B are as follows: solution A1, solution A2 and alkaline solution B are added dropwise to the container independently, the dropping speed is controlled, and the dropwise positions of solution A1, solution A2 and alkaline solution B in the container are different; stirring is carried out at the same time as dropping, and the stirring speed is 50-100 r / min.

3. The preparation method according to claim 2, characterized in that, The ratio of the dropping rates of solution A1 and solution A2 is (0.5-2):1; the ratio of the sum of the dropping rates of solution A1 and solution A2 to the dropping rate of alkaline solution B is (0.5-2):

1.

4. The preparation method according to claim 2, characterized in that, The mixing steps for solutions A1, A2, and alkaline solution B are as follows: solutions A1 and A2 are added dropwise along both sides of the container wall, and alkaline solution B is added dropwise to the center of the container.

5. The preparation method according to claim 1, characterized in that, In step S2, the atmosphere for the pyrolysis treatment is a mixture of hydrogen and nitrogen; in the mixture, the volume fraction of hydrogen is 10%-50%. And / or; the nickel source includes at least one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O; The rare earth metal source is at least one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, and Sc(NO3)3·4H2O; The aluminum source is at least one of Al(NO3)3·9H2O, AlCl3·6H2O, and Al2(SO4)3·18H2O.

6. The preparation method according to claim 1 or 4, characterized in that, In step S2, the molar ratio of Ni:(M+Al) is (2-6):1, where M is a rare earth metal element; the molar ratio of Al:M is (2-6):

1.

7. The preparation method according to claim 1, characterized in that, The pyrolysis treatment temperature is 500-700℃, and the pyrolysis treatment time is 1-4h.

8. A hydrodeoxygenation catalyst obtained by the preparation method according to any one of claims 1-7.

9. A method for converting light fractions of 1,4-cyclohexanediethanol distillation into liquid organic hydrogen carriers using the hydrodeoxygenation catalyst of claim 8, characterized in that, The method includes: The light fraction of 1,4-cyclohexanediethanol distillation and the aforementioned hydrodeoxygenation catalyst were mixed, and after being charged with hydrogen, the mixture was heated to obtain the liquid organic hydrogen carrier.

10. The method according to claim 9, characterized in that, The mass of the hydrodeoxygenation catalyst is 5-20% of the mass of the light fraction of the 1,4-cyclohexanediethanol distillation. And / or; the temperature of the heating reaction is 200-240℃; And / or; the pressure of the hydrogen gas is 4-8 MPa; And / or; the heating reaction time is 4-8 hours.

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