Hydroisomerization catalyst and its preparation method and use

Abstract

The present invention belongs to the field of catalysts, and specifically relates to a hydroisomerization catalyst, a preparation method thereof, and uses thereof. In the hydroisomerization catalyst provided by the present invention, by adjusting the large-pore silica-alumina molecular sieve, medium-pore silica-alumina molecular sieve, small-pore silica-alumina molecular sieve, and mesoporous molecular sieve to a specific ratio range, and adding amorphous silica-alumina, the pore size and acidity of the support can be regulated, thereby reducing the isomerization performance of the resulting catalyst while exhibiting relatively weak cracking catalytic performance, thereby controlling the isomerization and cracking degree of high-melting-point Fischer-Tropsch wax (melting point above 105°C), and having higher selectivity for the target product, which is conducive to the large-scale production of high-quality microcrystalline wax.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and in particular to a supported hydroisomerization catalyst and a preparation method thereof, use of the hydroisomerization catalyst in catalyzing Fischer-Tropsch wax to generate microcrystalline wax, and a preparation method of microcrystalline wax. Background Art

[0002] Microcrystalline wax is widely used in a variety of fields, including chemical, papermaking, food, power electronics, rubber protection, and precision casting. However, due to the annual decline in the production of petroleum-based microcrystalline wax and the continuous increase in demand, the price of microcrystalline wax is very high. In addition, food-grade microcrystalline wax is more difficult to process and has relatively low production volume, requiring more complex processing techniques and higher costs.

[0003] Currently, the catalyst described in patent application CN1516732A primarily uses amorphous silica-alumina as a carrier. The resulting microcrystalline wax products have limited adaptability, are relatively monotonous, and lack penetration comparable to corresponding petroleum-based microcrystalline wax grades. Patent application CN112808300A describes a process for producing microcrystalline wax using a Co-based catalyst as the active component. However, the resulting product has an extremely high oil content, requiring multiple deoiling processes to obtain the corresponding grade of microcrystalline wax.

[0004] Therefore, a simple and low-cost method to prepare microcrystalline wax is urgently needed. Summary of the Invention

[0005] The present invention aims to provide a hydroisomerization catalyst, a preparation method and use thereof, and a preparation method of microcrystalline wax, aiming to produce microcrystalline wax, especially high-quality microcrystalline wax, by a simpler method and at a lower cost.

[0006] In order to achieve the above-mentioned purpose of the invention, on the one hand, the present invention provides a hydroisomerization catalyst, which includes a carrier and a precious metal loaded on the carrier; wherein the carrier contains 10%-20% of medium-pore silica-alumina molecular sieve, 20%-40% of large-pore silica-alumina molecular sieve, 2%-10% of small-pore silica-alumina molecular sieve, 20%-40% of mesoporous molecular sieve, 10%-40% of amorphous silica-alumina, and 3%-10% of binder.

[0007] In some embodiments, the silicon-aluminum ratio of the medium-pore silica-aluminum molecular sieve is 0.2-0.5, the silicon-aluminum ratio of the large-pore silica-aluminum molecular sieve is 0.4-50, the silicon-aluminum ratio of the small-pore silica-aluminum molecular sieve is 0.3-0.8, and the silicon-aluminum ratio of the mesoporous molecular sieve is 20-80.

[0008] In some embodiments, the weight content of silicon dioxide in the amorphous silica-alumina is 10% to 70%.

[0009] In some embodiments, the acid amount of the carrier is 0.2-0.5 mmol / g.

[0010] In some embodiments, the noble metal is a Group VIII noble metal, preferably rhodium, palladium, and / or platinum.

[0011] In some embodiments, the loading amount of the precious metal is 0.1% to 0.35% based on the total weight of the hydroisomerization catalyst.

[0012] In some embodiments, the carrier is further loaded with an auxiliary agent, and the auxiliary agent is selected from at least one of cobalt, tungsten, tin, nickel, and vanadium; preferably, the metal molar ratio of the noble metal to the auxiliary agent is (1-5):1.

[0013] In some embodiments, the binder is selected from at least one of pseudo-boehmite, silica sol, and alumina sol.

[0014] In some embodiments, the pore size of the macroporous silica-alumina molecular sieve is The pore size of the mesoporous silica-alumina molecular sieve is The pore size of small pore silica-alumina molecular sieve is The pore size of the mesoporous molecular sieve is 2-50 nm.

[0015] In some embodiments, the macroporous silica-alumina molecular sieve is selected from ZSM-5 and / or SAPO-5.

[0016] In some embodiments, the mesoporous silica-alumina molecular sieve is selected from at least one of ZSM-25, ZSM-48, ZSM-57, SAPO-11, SAPO-31, and SAPO-41.

[0017] In some embodiments, the mesoporous molecular sieve is selected from MCM-41 and / or MCM-48.

[0018] In some embodiments, the small pore silica-alumina molecular sieve is selected from at least one of SAPO-34, SAPO-35, and SAPO-39.

[0019] In another aspect, the present invention provides a method for preparing a hydroisomerization catalyst, comprising the following steps:

[0020] Provide a carrier and a noble metal compound; wherein the carrier contains 10%-20% of medium-pore silica-alumina molecular sieve, 20%-40% of large-pore silica-alumina molecular sieve, 2%-10% of small-pore silica-alumina molecular sieve, 20%-40% of mesoporous molecular sieve, 10%-40% of amorphous silica-alumina, and 3%-10% of a binder.

[0021] The noble metal compound is loaded on the carrier, and subjected to calcination and reduction treatment to obtain a hydroisomerization catalyst.

[0022] In some embodiments, the step of loading the precious metal compound onto the support further includes loading an auxiliary compound onto the support, wherein the auxiliary compound is a salt containing at least one of cobalt, tungsten, tin, nickel, and vanadium.

[0023] In some embodiments, the noble metal compound and the auxiliary compound (if any) are loaded on the carrier by impregnation; preferably, the impregnation time is 2-10 hours.

[0024] In another aspect, the present invention further provides use of the hydroisomerization catalyst in catalyzing the hydroisomerization / cracking of Fischer-Tropsch wax.

[0025] In some embodiments, the Fischer-Tropsch wax has a drop melting point of 105°C or above.

[0026] In some embodiments, the product of the hydroisomerization / cracking of Fischer-Tropsch wax catalyzed by the hydroisomerization catalyst is microcrystalline wax, preferably food-grade microcrystalline wax.

[0027] Finally, the present invention further provides a method for preparing microcrystalline wax, comprising the step of contacting the hydroisomerization catalyst of the present invention with Fischer-Tropsch wax under hydroisomerization / cracking conditions.

[0028] In some embodiments, the Fischer-Tropsch wax has a drop melting point greater than 105°C.

[0029] In some embodiments, the microcrystalline wax is food grade microcrystalline wax.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] First, in the hydrogenation isomerization catalyst provided by the present invention, by adjusting the large-pore silica-alumina molecular sieve, the medium-pore silica-alumina molecular sieve, the small-pore silica-alumina molecular sieve and the mesoporous molecular sieve to a specific ratio range, and adding amorphous silica-alumina, the pore size and acidity of the carrier can be regulated, thereby reducing the isomerization performance of the obtained catalyst while showing relatively weak cracking catalytic performance, so as to control the isomerization and cracking degree of high-melting-point Fischer-Tropsch wax (melting point is above 105°C), effectively converting the long straight alkanes in the Fischer-Tropsch wax into multi-branched isomerized alkanes, while maintaining the solid form of the wax, so that the obtained product is wax-like.

[0032] Secondly, the hydroisomerization catalyst provided by the present invention exhibits excellent high-temperature activity. When catalyzing high-melting-point Fischer-Tropsch wax, the reaction conditions are milder than those used in cracking catalysis, and selectivity for the target product is higher. The yield of products exceeding 500°C is significantly increased, facilitating the large-scale production of high-quality microcrystalline wax. Furthermore, the hydroisomerization catalyst provided by the present invention has a low precious metal loading and a service life of over 5,000 hours, significantly reducing its cost. DETAILED DESCRIPTION

[0033] First, the present invention provides a method for preparing a hydroisomerization catalyst, which comprises the following steps:

[0034] (1) providing a carrier and a noble metal compound; wherein, based on the total weight of the carrier, the carrier contains 10%-20% of a medium-pore silica-alumina molecular sieve, 20%-40% of a large-pore silica-alumina molecular sieve, 2%-10% of a small-pore silica-alumina molecular sieve, 20%-40% of a mesoporous molecular sieve, 10%-40% of an amorphous silica-alumina, and 3%-10% of a binder;

[0035] (2) The noble metal compound is loaded on the carrier, and subjected to calcination and reduction treatment to obtain a hydroisomerization catalyst.

[0036] The preparation method provided by the present invention prepares a supported hydroisomerization catalyst, wherein the carrier is a composite carrier containing a specific proportion of medium-pore silica-alumina molecular sieve, large-pore silica-alumina molecular sieve, mesoporous molecular sieve, small-pore silica-alumina molecular sieve, amorphous silica-alumina and a binder. By mixing the above components in a specific proportion, the pore size and acidity of the carrier can be adjusted to a suitable range, so that the resulting catalyst can catalyze high-melting-point Fischer-Tropsch wax to obtain microcrystalline wax. Among them, by adjusting the pore size of the carrier, the selectivity of the product can be controlled to obtain long-chain isomerized microcrystalline wax; by adjusting the acidity of the carrier, the cracking performance of the resulting catalyst can be adjusted to avoid the cracking of wax into gasoline and diesel due to the high acidity of the catalyst. The preparation method provided by the present invention is simple in process and easy to repeat. It is suitable for large-scale production of high-quality microcrystalline wax products and can reduce the production cost of microcrystalline wax (especially high-quality microcrystalline wax such as food-grade microcrystalline wax). Finally, the catalyst prepared by the preparation method provided by the present invention has high selectivity and high product yield.

[0037] Specifically, in step (1), the carrier is used to load active substances such as precious metals, wherein the large-pore silica-alumina molecular sieve, the medium-pore silica-alumina molecular sieve and the small-pore silica-alumina molecular sieve are all microporous molecular sieves. In some embodiments, the pore size range of the large-pore silica-alumina molecular sieve is The pore size range of the mesoporous silica-alumina molecular sieve is The pore size range of the small pore silica-alumina molecular sieve is The pore size of the mesoporous molecular sieve is 2-50 nm.

[0038] In some embodiments, the silicon-aluminum ratio of the medium-pore silicon-aluminum molecular sieve is 0.2-0.5, the silicon-aluminum ratio of the large-pore silicon-aluminum molecular sieve is 0.4-50, the silicon-aluminum ratio of the small-pore silicon-aluminum molecular sieve is 0.3-0.8, and the silicon-aluminum ratio of the mesoporous molecular sieve is 20-80. Different silicon-aluminum ratios result in different acid amounts in the molecular sieves. By selecting large-pore silicon-aluminum molecular sieves, medium-pore silicon-aluminum molecular sieves, small-pore silicon-aluminum molecular sieves, and mesoporous molecular sieves within a specific silicon-aluminum ratio range, the present invention can further control the acidity of the resulting catalyst and improve its product selectivity.

[0039] In some specific embodiments, the macroporous silica-alumina molecules are sieved from ZSM-5 and / or SAPO-5; the medium-pore silica-alumina molecules are sieved from at least one of ZSM-25, ZSM-48, ZSM-57, SAPO-11, SAPO-31, and SAPO-41, preferably ZSM-25 and / or SAPO-31; the mesoporous molecules are sieved from MCM-41 and / or MCM-48; the small-pore silica-alumina molecules are sieved from at least one of SAPO-34, SAPO-35, and SAPO-39, preferably SAPO-34.

[0040] The present invention mixes amorphous silica-alumina with large-pore silica-alumina molecular sieves, medium-pore silica-alumina molecular sieves, small-pore molecular sieves, and mesoporous molecular sieves in specific proportions to control the acidity of the carrier and the resulting catalyst. The higher the silicon content in the amorphous silica-alumina, the lower the acidity of the carrier and catalyst. In some embodiments, the silica content of the amorphous silica-alumina is 10% to 70% by weight. In some embodiments, the amorphous silica-alumina is amorphous silica-alumina powder.

[0041] In some embodiments, the binder is selected from at least one of pseudo-boehmite, silica sol, alumina sol, and alumina powder, preferably silica sol.

[0042] In some embodiments, the acid amount of the carrier is 0.2-0.5 mmol / g.

[0043] Precious metal compounds, as precursors to the active components of the catalyst, are the primary raw material for the catalyst to exert its catalytic activity. In some embodiments, the precious metal compound is a compound containing a Group VIII precious metal element, such as at least one of ruthenium, osmium, palladium, platinum, rhodium, and iridium. In some preferred embodiments, the precious metal compound is a compound containing rhodium, palladium, and / or platinum.

[0044] In some embodiments, the support is made of SAPO-5 molecular sieve, SAPO-31 molecular sieve, MCM-41 molecular sieve, SAPO-34 molecular sieve, amorphous silica-alumina powder (silicon dioxide content 20%) and silica sol as a binder.

[0045] In some embodiments, the carrier is made of SAPO-5 molecular sieve, SAPO-31 molecular sieve, MCM-41 molecular sieve, SAPO-34 molecular sieve, amorphous silica-alumina (silicon dioxide content 20%) and a binder, and the weight ratio of SAPO-5 molecular sieve, SAPO-31 molecular sieve, MCM-41 molecular sieve, SAPO-34 molecular sieve, amorphous silica-alumina and binder is 5:3:6:1:8:1.

[0046] The carrier of the present invention can be prepared using methods commonly used in the art. In some embodiments, the carrier preparation method includes: mixing or ball milling the raw materials in proportion, extruding, and calcining to obtain the carrier. It should be understood that the methods and conditions of mixing, ball milling, extruding, and calcining are conventional conditions in the art and are within the scope of routine adjustment by those skilled in the art based on actual conditions. In some embodiments, the calcination temperature is 400-600°C and the calcination time is 4 hours or more.

[0047] In step (2), in some embodiments, the step of loading the precious metal compound onto the support further includes loading a promoter compound onto the support. The promoter compound is a salt containing at least one of cobalt, tungsten, tin, nickel, and vanadium. The promoter compound serves as a precursor to the promoter, and is used to enhance the hydrogenation performance of the catalyst, thereby improving the stability of the wax.

[0048] The method for loading the noble metal compound (and the auxiliary compound) onto the support can be conventional methods in the art. Preferably, the noble metal compound (and the auxiliary compound) is loaded onto the support by an impregnation method. More preferably, the impregnation method is an equal volume impregnation method. Furthermore, the impregnation time is 2-10 hours.

[0049] After the loading is completed, the carrier loaded with the precious metal compound (and the auxiliary compound) can be dried, calcined, and reduced by conventional methods in the art to obtain a hydroisomerization catalyst. In some embodiments, the drying temperature is 50-120°C and the drying time is 2-12 hours; the calcination temperature is 300-450°C and the calcination time is 2-8 hours; the reduction treatment is to heat the temperature to 250-450°C under a reducing atmosphere and maintain it for 2-6 hours. The reducing atmosphere can be hydrogen, preferably with a space velocity of 3000-6000h -1In some preferred embodiments, the heating rate is 1-3°C / min.

[0050] In some embodiments, a passivation treatment is further performed after the reduction treatment to further stabilize the resulting catalyst. Specifically, the passivation treatment is performed in an oxygen-containing atmosphere at a temperature of 20-120° C. for 2-5 hours. The oxygen-containing atmosphere is preferably an O2 / N2 mixed atmosphere having an oxygen content of 1%-10%.

[0051] In some embodiments, the loading amount of the precious metal in the obtained hydroisomerization catalyst is 0.1%-0.35% based on the total weight of the hydroisomerization catalyst.

[0052] In some embodiments, the molar ratio of the noble metal to the auxiliary agent in the obtained hydroisomerization catalyst is (1-5): 1. At this ratio, the synergistic effect of the noble metal and the auxiliary agent can be promoted, and the noble metal and the auxiliary agent are well dispersed on the support surface.

[0053] The hydroisomerization catalyst provided by the present invention can be prepared by the above preparation method.

[0054] Correspondingly, the present invention provides a hydroisomerization catalyst, which includes a carrier and a precious metal loaded on the carrier; wherein, based on the total weight of the carrier, the carrier contains 10%-20% of medium-pore silica-alumina molecular sieve, 20%-40% of large-pore silica-alumina molecular sieve, 2%-10% of small-pore silica-alumina molecular sieve, 20%-40% of mesoporous molecular sieve, 10%-40% of amorphous silica-alumina, and 3%-10% of binder.

[0055] The hydroisomerization catalyst provided by the present invention exhibits relatively weak cracking catalytic performance while reducing the isomerization performance, so as to better control the isomerization and cracking degree of high-melting-point Fischer-Tropsch wax (melting point above 105°C), avoid serious cracking and isomerization of the product, and effectively convert the long straight alkanes in the Fischer-Tropsch wax into multi-branched isoalkanes, while maintaining the solid form of the wax, so that the resulting product is waxy. At the same time, the hydroisomerization catalyst carrier provided by the present invention has good high-temperature thermal conductivity. When catalyzing high-melting-point Fischer-Tropsch wax, the reaction conditions are milder than those of the cracking catalytic reaction, and the selectivity for the target product is higher. The product with a yield greater than 500°C is significantly increased, which is conducive to the large-scale production of high-quality food-grade microcrystalline wax products.

[0056] In some embodiments, the acid content of the hydroisomerization catalyst is 0.3 mmol / g. The higher the acid content, the greater the acidity of the catalyst, the better the hydroisomerization performance, and thus the higher the selectivity of the isomerized base oil product. Therefore, controlling the acidity is particularly important for the selectivity of the microcrystalline wax product.

[0057] In the hydroisomerization catalyst provided by the present invention, the components and contents of the carrier, the loading amounts of the precious metal and the additive, etc. are the same as those described in the preparation method of the hydroisomerization catalyst described above and will not be repeated here.

[0058] In some embodiments, the noble metal is a Group VIII noble metal, preferably rhodium, palladium, and / or platinum.

[0059] In some embodiments, the carrier is further loaded with an auxiliary agent, and the auxiliary agent is selected from at least one of cobalt, tungsten, tin, nickel, and vanadium; preferably, the metal molar ratio of the noble metal to the auxiliary agent is (1-5):1.

[0060] The hydroisomerization catalyst provided by the present invention can be used to catalyze the hydroisomerization / cracking of Fischer-Tropsch wax. In some embodiments, the catalyst can be used to catalyze the hydroisomerization / cracking of Fischer-Tropsch wax to obtain microcrystalline wax.

[0061] Preferably, the drop melting point of the Fischer-Tropsch wax is above 105° C. If the drop melting point of the Fischer-Tropsch wax is less than 105° C., severe isomerization problems may occur when the hydroisomerization catalyst provided by the present invention is used for catalysis, making it difficult to obtain microcrystalline wax, or difficult to obtain food-grade microcrystalline wax.

[0062] Preferably, the microcrystalline wax is food-grade microcrystalline wax. When the melting point of Fischer-Tropsch wax is above 105°C, the carbon chain is relatively longer and less prone to cracking, making it easier to obtain long-chain food-grade isomerized microcrystalline wax with a higher yield.

[0063] Correspondingly, the present invention also provides a method for preparing microcrystalline wax, which comprises the step of contacting the hydroisomerization catalyst provided by the present invention with Fischer-Tropsch wax under hydroisomerization / cracking conditions.

[0064] In some embodiments, the drop melting point of the Fischer-Tropsch wax is above 105° C. If the drop melting point of the Fischer-Tropsch wax is less than 105° C., severe isomerization problems may occur when the hydroisomerization catalyst provided by the present invention is used for catalysis, making it difficult to obtain microcrystalline wax, or difficult to obtain food-grade microcrystalline wax.

[0065] In some embodiments, the microcrystalline wax is food-grade microcrystalline wax. When the melting point of Fischer-Tropsch wax is above 105°C, the carbon chain is relatively longer and less prone to cracking, making it easier to obtain long-chain food-grade isomerized microcrystalline wax with higher yield.

[0066] In some embodiments, the feed reaction space velocity of the Fischer-Tropsch wax is 0.8-1.5h -1 .

[0067] Catalyst-catalyzed hydroisomerization / cracking reaction is a known reaction type in the present invention and can be carried out under conventional hydroisomerization / cracking conditions in the art.

[0068] In order to make the above implementation details and operations of the present invention clearly understood by those skilled in the art, and to demonstrate the significant improvement in performance of the hydroisomerization catalyst, preparation method, and use thereof according to the embodiments of the present invention, the above technical solution is illustrated by multiple embodiments below.

[0069] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0070] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0071] Example 1

[0072] This embodiment provides a method for preparing a specific hydroisomerization catalyst of the present invention, which is as follows:

[0073] (11) 25 g of SAPO-5 molecular sieve (silicon-aluminum ratio of 0.45), 15 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.25), 30 g of MCM-41 molecular sieve (silicon-aluminum ratio of 50), 5 g of SAPO-34 molecular sieve (silicon-aluminum ratio of 0.5), and 40 g of amorphous silica-aluminum powder (silicon dioxide content of 20%) were weighed and poured into a kneader and stirred for 0.5 h. A mixed solution of 5 g of 40% silica sol, 10 mL of glacial acetic acid, and 80 mL of deionized water was added. The mixture was kneaded and extruded into strips with a diameter of 1.5 mm, and then dried at 120°C and calcined at 450°C for 5 h to obtain a carrier with an acid content of 0.48 mmol / g.

[0074] (12) Weigh 20 g of the support prepared in step (11), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and immerse it in an equal volume by ultrasonication at room temperature for 4 h. Then, dry it by rotary evaporation at 80 ° C. and calcine it at 350 ° C. for 4 h to obtain a catalyst precursor.

[0075] (13) The catalyst precursor obtained in step (12) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0076] Example 2

[0077] This embodiment provides a method for preparing a specific hydroisomerization catalyst of the present invention, which is as follows:

[0078] (21) 30 g of SAPO-5 molecular sieve (silicon-aluminum ratio of 0.5), 20 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.25), 30 g of MCM-41 molecular sieve (silicon-aluminum ratio of 50), 10 g of SAPO-34 molecular sieve (silicon-aluminum ratio of 0.5), and 40 g of amorphous silica-aluminum powder (silicon dioxide content of 40%) were poured into a kneader and stirred for 0.5 h. Then, a mixed solution of 5 g of 40% aluminum sol, 12 mL of glacial acetic acid, and 90 mL of deionized water was added. The mixture was kneaded and extruded into strips with a diameter of 1.5 mm, and then dried at 120 ° C and calcined at 450 ° C for 5 h to obtain a carrier with an acid content of 0.31 mmol / L.

[0079] (22) Weigh 20 g of the support prepared in step (21), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 ° C. and calcine it at 350 ° C. for 4 h to obtain a catalyst precursor.

[0080] (23) The catalyst precursor obtained in step (22) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0081] Example 3

[0082] This embodiment provides a method for preparing a specific hydroisomerization catalyst of the present invention, which is as follows:

[0083] (31) 35 g of SAPO-5 molecular sieve (silicon-aluminum ratio of 0.5), 18 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.3), 40 g of MCM-41 molecular sieve (silicon-aluminum ratio of 50), 8 g of SAPO-34 molecular sieve (silicon-aluminum ratio of 0.5), 40 g of amorphous silica-aluminum powder (silicon dioxide content of 60%) and 5 g of alumina powder were weighed and poured into a kneader and stirred for 0.5 h. Then, a mixed solution of 15 mL of glacial acetic acid and 105 mL of deionized water was added. The mixture was kneaded and extruded into strips with a diameter of 1.5 mm, and then dried at 120 ° C and calcined at 450 ° C for 5 h to obtain a carrier with an acid content of 0.25 mmol / g.

[0084] (32) Weigh 20 g of the support prepared in step (31), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 ° C. and calcine it at 350 ° C. for 4 h to obtain a catalyst precursor.

[0085] (33) The catalyst precursor obtained in step (32) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0086] Example 4

[0087] This embodiment provides a method for preparing a specific hydroisomerization catalyst of the present invention, which is as follows:

[0088] (41) 40 g of SAPO-5 molecular sieve (silicon-aluminum ratio of 0.45), 20 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.45), 40 g of MCM-41 molecular sieve (silicon-aluminum ratio of 70), 10 g of SAPO-34 molecular sieve (silicon-aluminum ratio of 0.6), 50 g of amorphous silica-aluminum powder (silicon dioxide content of 10%), and 5 g of alumina powder were poured into a kneader and stirred for 0.5 h. A mixed solution of 20 mL of glacial acetic acid and 120 mL of deionized water was added, and the mixture was kneaded and extruded into strips with a diameter of 1.5 mm. The strips were then dried at 120 °C and calcined at 450 °C for 5 h to obtain a carrier with an acid content of 0.42 mmol / g.

[0089] (42) Weigh 20 g of the support prepared in step (41), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 ° C. and calcine it at 350 ° C. for 4 h to obtain a catalyst precursor.

[0090] (43) The catalyst precursor obtained in step (42) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0091] Example 5

[0092] (51) 45 g of SAPO-5 molecular sieve (silicon-aluminum ratio of 0.55), 25 g of SAPO-41 molecular sieve (silicon-aluminum ratio of 0.45), 50 g of MCM-48 molecular sieve (silicon-aluminum ratio of 70), 10 g of SAPO-35 molecular sieve (silicon-aluminum ratio of 0.6), and 60 g of amorphous silica-aluminum powder (silicon dioxide content of 70%) were poured into a kneader and stirred for 0.5 h. A mixed solution of 8 g of 40% silica sol, 30 mL of glacial acetic acid, and 130 mL of deionized water was added. The mixture was kneaded with 8 g of silica sol and extruded into strips with a diameter of 1.5 mm. The strips were then dried at 120 °C and calcined at 450 °C for 5 h to obtain a carrier with an acid content of 0.22 mmol / g.

[0093] (52) Weigh 20 g of the support prepared in step (51), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 °C and calcine it at 350 °C for 4 h to obtain a catalyst precursor.

[0094] (53) The catalyst precursor obtained in step (52) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0095] Comparative Example 1

[0096] This comparative example provides a preparation method of a hydroisomerization catalyst, which is as follows:

[0097] (61) 100 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.4), 15 g of amorphous silica-aluminum powder (silicon dioxide content 70%), and 5 g of alumina powder were poured into a kneader and stirred for 0.5 h. A mixed solution of 8 mL of glacial acetic acid and 70 mL of deionized water was added and kneaded to prepare strips with a diameter of 1.5 mm. The strips were then dried at 120 °C and calcined at 450 °C for 5 h to obtain a carrier with an acid content of 0.65 mmol / g.

[0098] (62) Weigh 20 g of the support prepared in step (61), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 °C and calcine it at 350 °C for 4 h to obtain a catalyst precursor.

[0099] (63) The catalyst precursor obtained in step (62) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0100] Comparative Example 2

[0101] This comparative example provides a preparation method of a hydroisomerization catalyst, which is as follows:

[0102] (71) 60 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.35), 20 g of amorphous silica-aluminum powder (silicon dioxide content of 80%), and 5 g of alumina powder were weighed and poured into a kneader and stirred for 0.5 h. A mixed solution of 6 mL of glacial acetic acid and 50 mL of deionized water was added and kneaded to prepare strips with a diameter of 1.5 mm. The strips were then dried at 120 °C and calcined at 450 °C for 5 h to obtain a carrier with an acid content of 0.55 mmol / g.

[0103] (72) Weigh 20 g of the support prepared in step (71), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate, and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 °C and calcine it at 350 °C for 4 h to obtain a catalyst precursor.

[0104] (73) The catalyst precursor obtained in step (72) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0105] Comparative Example 3

[0106] This comparative example provides a preparation method of a hydroisomerization catalyst, which is as follows:

[0107] (81) 80 g of SAPO-31 molecular sieve (silicon-aluminum ratio of 0.25), 10 g of MCM-41 molecular sieve (silicon-aluminum ratio of 40), 10 g of amorphous silica-aluminum powder (silicon dioxide content of 60%), and 5 g of alumina powder were weighed and poured into a kneader and stirred for 0.5 h. A mixed solution of 8 mL of glacial acetic acid and 70 mL of deionized water was added and kneaded to prepare strips with a diameter of 1.5 mm. The strips were then dried at 120 °C and calcined at 450 °C for 5 h to obtain a carrier with an acid content of 0.58 mmol / g.

[0108] (82) Weigh 20 g of the support prepared in step (71), weigh 0.105 g of platinum chloride and 0.053 g of tin oxalate, and dissolve them in 17 mL of deionized water. Pour the support into the mixed solution and ultrasonically immerse it in an equal volume for 4 h at room temperature. Then, dry it by rotary evaporation at 80 °C and calcine it at 350 °C for 4 h to obtain a catalyst precursor.

[0109] (83) The catalyst precursor obtained in step (82) was heated to 300°C at a rate of 2°C / min under H2 atmosphere and reduced at this temperature for 4 h with a H2 space velocity of 3500 h -1 After the H2 atmosphere was cooled to room temperature, the catalyst was passivated with O2 / N2 having an O2 content of 5% for 4 h to obtain a hydroisomerization catalyst loaded with 0.3% Pt (wt.) and 0.15% Sn (wt.).

[0110] Experimental example

[0111] This experimental example tested the hydroisomerization catalysts obtained in Examples 1-5 and Comparative Examples 1-3 to catalyze high melting point Fischer-Tropsch wax (melting point above 105° C.) to prepare microcrystalline wax.

[0112] The test conditions are as follows: the catalytic reaction was carried out in a fixed bed reactor. The hydroisomerization catalysts obtained in Examples 1-5 and Comparative Examples 1-3 were tested separately, with a loading volume of 10 mL and a hydrogen gas space velocity (GHSV) of 500 h -1 The liquid hourly space velocity (LHSV) of high melting point Fischer-Tropsch wax (melting point above 105°C) is 1.0h -1 The H2 / oil ratio was 500:1, the reaction pressure was 6.5 MPa, and the reaction temperature was 305°C. The reaction product was collected in a high-purity tank and the liquid product was sampled for analysis of carbon number distribution and product distribution by gas chromatography, and its drop melting point was determined.

[0113] The physical properties of the products obtained by subjecting the hydroisomerization catalysts obtained in Examples 1-5 and Comparative Examples 1-3 to the above catalytic reactions are shown in Table 1.

[0114] Table 1

[0115]

[0116]

[0117] As can be seen from Table 1, compared with the conventional hydroisomerization catalysts prepared in Comparative Examples 1-3, Examples 1-5 of the present invention adjust the large-pore silica-alumina molecular sieve, medium-pore silica-alumina molecular sieve, small-pore silica-alumina molecular sieve and mesoporous molecular sieve to a specific ratio range, and add weakly acidic amorphous silica-alumina to prepare the carrier. The resulting hydroisomerization catalyst can significantly increase the yield of food-grade microcrystalline wax products with a yield greater than 500°C when catalyzing high-melting point Fischer-Tropsch wax.

[0118] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A hydroisomerization catalyst, characterized in that The invention comprises a carrier and a noble metal supported on the carrier; wherein, based on the total weight of the carrier, the carrier contains 10%-20% of a medium-pore silica-alumina molecular sieve, 20%-40% of a large-pore silica-alumina molecular sieve, 2%-10% of a small-pore silica-alumina molecular sieve, 20%-40% of a mesoporous molecular sieve, 10%-40% of amorphous silica-alumina, and 3%-10% of a binder; Wherein, the pore size of the macroporous silica-alumina molecular sieve is The pore size of the mesoporous silica-alumina molecular sieve is The pore size of small pore silica-alumina molecular sieve is The pore size of the mesoporous molecular sieve is 2-50 nm.

2. The hydroisomerization catalyst according to claim 1, characterized in that The silicon-aluminum ratio of the medium-pore silicon-aluminum molecular sieve is 0.2-0.5, the silicon-aluminum ratio of the large-pore silicon-aluminum molecular sieve is 0.4-50, the silicon-aluminum ratio of the small-pore silicon-aluminum molecular sieve is 0.3-0.8, and the silicon-aluminum ratio of the mesoporous molecular sieve is 20-80.

3. The hydroisomerization catalyst according to claim 1, characterized in that The weight content of silicon dioxide in the amorphous silicon aluminum is 10%-70%.

4. The hydroisomerization catalyst according to claim 1, characterized in that The acid content of the carrier is 0.2-0.5 mmol / g.

5. The hydroisomerization catalyst according to claim 1, characterized in that The noble metal is a Group VIII noble metal; and / or Based on the total weight of the hydroisomerization catalyst, the loading amount of the noble metal is 0.1%-0.35%.

6. The hydroisomerization catalyst according to claim 5, characterized in that The noble metal is rhodium, palladium and / or platinum.

7. The hydroisomerization catalyst according to any one of claims 1 to 6, characterized in that The carrier is further loaded with an auxiliary agent, and the auxiliary agent is selected from at least one of cobalt, tungsten, tin, nickel, and vanadium.

8. The hydroisomerization catalyst according to claim 7, characterized in that The metal molar ratio of the noble metal to the auxiliary agent is (1-5):

1.

9. A method for preparing a hydroisomerization catalyst, characterized in that: The steps include: A carrier and a noble metal compound are provided; wherein, based on the total weight of the carrier, the carrier contains 10%-20% of a medium-pore silica-alumina molecular sieve, 20%-40% of a large-pore silica-alumina molecular sieve, 5%-15% of a small-pore silica-alumina molecular sieve, 20%-40% of a mesoporous molecular sieve, 10%-40% of amorphous silica-alumina powder, and 3%-10% of a binder; The noble metal compound is loaded on the carrier, and subjected to calcination and reduction treatment to obtain a hydroisomerization catalyst; Wherein, the pore size of the macroporous silica-alumina molecular sieve is The pore size of the mesoporous silica-alumina molecular sieve is The pore size of small pore silica-alumina molecular sieve is The pore size of the mesoporous molecular sieve is 2-50 nm.

10. Use of the hydroisomerization catalyst according to any one of claims 1 to 8, or the hydroisomerization catalyst prepared by the preparation method according to claim 9, in catalyzing the hydroisomerization / cracking of Fischer-Tropsch wax.

11. A method for preparing microcrystalline wax, characterized in that: include: A step of contacting the hydroisomerization catalyst according to any one of claims 1 to 8 with Fischer-Tropsch wax under hydroisomerization / cracking conditions.

12. The preparation method according to claim 11, characterized in that The Fischer-Tropsch wax has a melting point of 105° C. or higher; and / or The microcrystalline wax is food grade microcrystalline wax.

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