Catalyst for diesel oil isomerization pour point depression and preparation method and application thereof
By using cerium-zirconium solid solution and yttrium-modified catalysts, the problems of poor tolerance and insufficient stability of existing precious metal catalysts in the diesel isomerization dewaxing process were solved, achieving high efficiency in diesel low-temperature fluidity and high liquid yield.
Patent Information
- Application Number
- CN202510909688.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-11-04
AI Technical Summary
Existing precious metal catalysts have poor tolerance to diesel isomerization and dewaxing processes, are prone to poisoning and reduced activity, and are prone to excessive cracking reactions under high activity conditions. They are difficult to balance low pour point and high yield, have high cost, and insufficient stability and lifespan.
The catalyst was modified by synergistic modification with cerium-zirconium solid solution and yttrium metal. By controlling the electronic structure and acidity distribution of the catalyst, the resistance to poisoning and selectivity were enhanced, and the stability was improved.
It improves the catalyst's resistance to poisoning and stability, optimizes acidity distribution, enhances the efficiency and liquid yield of diesel isomerization dewaxing, lowers the pour point, and maintains a high cetane number.
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of catalysts, and particularly relates to a catalyst for diesel isomerization and pour point reduction, and a preparation method and application thereof. BACKGROUND
[0002] With the growth of global energy demand and the increasing stringency of environmental protection regulations, producing clean diesel with high quality and low condensation point has become an important goal of the oil refining industry. Normal alkanes in diesel are prone to form wax crystals at low temperatures, which leads to an increase in condensation point and cloud point, limiting its storage, transportation and use performance in cold regions. Isomerization and pour point reduction technology can effectively reduce the condensation point of diesel by catalytically converting normal alkanes into branched alkanes, while maintaining a high liquid yield and cetane number, which is the main technical means to improve the low-temperature fluidity of diesel.
[0003] In the prior art, noble metal catalysts (such as platinum Pt and palladium Pd) are widely used in diesel isomerization and pour point reduction processes due to their excellent hydrogenation and isomerization activity. These catalysts are usually supported on an acidic molecular sieve carrier (such as SAPO-11, ZSM-5 or beta zeolite), and the isomerization reaction is catalyzed by the acidic sites, while the noble metal sites provide hydrogenation function, and the two work together to achieve high-efficiency pour point reduction. However, the existing noble metal catalysts have the following disadvantages: poor tolerance to impurities such as sulfur and nitrogen in the raw material, easy catalyst poisoning, leading to a decrease in activity; under high activity conditions, excessive cracking reactions are easily induced, reducing the liquid yield; the cost of noble metals is high, limiting the economic efficiency of the catalyst. In addition, the existing catalysts are difficult to balance the low condensation point target and high yield when processing diesel raw materials with high wax content or complex components, and the stability and service life of the catalysts need to be improved. SUMMARY
[0004] In view of the above technical problems, the purpose of the present application is to provide a preparation method of a catalyst for diesel isomerization and pour point reduction. The cerium-zirconium solid solution used in the method has significant potential in catalyst modification due to its excellent redox performance, thermal stability and oxygen storage capacity. Metal yttrium (Y) has unique electronic structure and chemical properties, which can regulate the acid distribution and surface properties of the catalyst, enhance the resistance to poisoning and selectivity, and improve the stability of the catalyst. By introducing the cerium-zirconium solid solution and metal yttrium into the catalyst system, the electronic structure and acid distribution of the catalyst can be optimized, and the resistance to poisoning, selectivity and stability can be improved.
[0005] The present application is realized by the following technical solutions:
[0006] A preparation method of a catalyst for diesel isomerization and pour point reduction, comprising the following steps:
[0007] S1, selecting pseudo-boehmite, cerium zirconium solid solution and phosphosilicate aluminum molecular sieve, adding into a kneader, mixing, slowly adding acid solution, continuing to knead to form uniform wet material, transferring to an extruder for extrusion molding, standing at room temperature, drying, baking, obtaining a carrier;
[0008] S2, the prepared yttrium nitrate impregnation solution is evenly impregnated on the carrier in equal volume, after the impregnation solution is fully adsorbed, drying, baking, obtaining a yttrium modified carrier;
[0009] S3, the prepared chloroplatinic acid impregnation solution is evenly impregnated on the yttrium modified carrier in equal volume, after the impregnation solution is fully adsorbed, drying, baking, obtaining a carrier.
[0010] As preferably, in the S1, the mass ratio of pseudo-boehmite, cerium zirconium solid solution and phosphosilicate aluminum molecular sieve is 3:1:1.
[0011] As preferably, in the S1, the kneading time of the kneader is 15-20 min.
[0012] As preferably, in the S1, the mass percentage concentration of the acid solution is 3% nitric acid aqueous solution.
[0013] As preferably, in the S1, the ratio of acid solution to pseudo-boehmite is 100-200 mL: 150-300 g.
[0014] The kneading time of the acid solution is 15-20 min.
[0015] As preferably, in the S1, the standing time is 10-12 h.
[0016] Drying in an oven at 80-100℃ for 7-8h; baking at 450-500℃ with a temperature rising rate of 5℃ / min for 3.5-4h.
[0017] As preferably, in the S2, yttrium nitrate and deionized water are mixed in a ratio of 14-30g: 50mL to configure the yttrium nitrate impregnation solution.
[0018] Drying in an oven at 80-100℃ for 7-8h; baking at 450-500℃ with a temperature rising rate of 5℃ / min for 3.5-4h.
[0019] As preferably, in the S3, chloroplatinic acid and deionized water are mixed in a ratio of 1-2g: 50mL to configure the chloroplatinic acid impregnation solution.
[0020] Drying in an oven at 80-100℃ for 7-8h; baking at 450-500℃ with a temperature rising rate of 5℃ / min for 3.5-4h.
[0021] The application relates to a catalyst for diesel isomerization and pour point depression, and a preparation method thereof.
[0022] The application relates to a catalyst for diesel isomerization and pour point depression, and application of the catalyst in improving low-temperature fluidity of diesel.
[0023] Compared with the prior art, the application has at least the following technical effects:
[0024] The application provides a preparation method of a catalyst for diesel isomerization and pour point depression. DETAILED DESCRIPTION
[0025] The embodiments of the application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used for illustrating the application and should not be regarded as limiting the scope of the application, and the specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturers, and the reagents or instruments not mentioned by the manufacturers are all conventional products that can be purchased on the market.
[0026] Example 1
[0027] The application relates to a preparation method of a catalyst for diesel isomerization and pour point depression.
[0028] 300g pseudo-boehmite, 100g cerium-zirconium solid solution and 100g SAPO-11 are added into a kneader and mixed for 20min to ensure uniform dispersion of the materials, 200mL of 3% (w / w) nitric acid aqueous solution is slowly added, and the kneading is continued for 20min to form a uniform wet material, the wet material is transferred to an extruder for extrusion molding, and then is placed in a 100 DEG C oven for drying for 8h, and then is heated to 500 DEG C at a rate of 5 DEG C / min and calcined for 4h to obtain a carrier.
[0029] 100g of the carrier is taken, 14.46g of yttrium nitrate (Y(NO3)3) is dissolved in 50mL of deionized water, and the mixture is stirred until the yttrium nitrate is completely dissolved to prepare a yttrium nitrate impregnation solution, the carrier is impregnated with the same volume of the yttrium nitrate impregnation solution, and the solution is fully adsorbed, the carrier is dried in a 100 DEG C oven for 8h, and then is heated to 500 DEG C at a rate of 5 DEG C / min and calcined for 4h to obtain a yttrium-modified carrier.
[0030] Dissolve 1.47 g chloroplatinic acid (H2PtCl6) in 50 mL deionized water, stir until dissolved, impregnate an equal volume on the yttrium modified support, dry at 100 °C for 8 h, heat to 500 °C at 5 °C / min, and calcine for 4 h to obtain catalyst A.
[0031] Example 2:
[0032] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0033] Add 300 g pseudoboehmite, 100 g ceria-zirconia solid solution, and 100 g SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the materials. Slowly add 200 mL of 3% (w / w) nitric acid aqueous solution and continue kneading for 20 min to form a uniform wet material. Transfer the wet material to an extruder for extrusion molding. After standing at room temperature for 12 h, place the material in a 100 °C oven for drying for 8 h, and then heat to 500 °C at 5 °C / min and calcine for 4 h to obtain the support.
[0034] Take 100 g of the support, dissolve 23.19 g yttrium nitrate (Y(NO3)3) in 50 mL deionized water, and stir until completely dissolved to prepare a yttrium nitrate impregnation solution. Impregnate an equal volume of the yttrium nitrate impregnation solution on the support to ensure sufficient adsorption of the solution. Dry the impregnated support in a 100 °C oven for 8 h, and then heat to 500 °C at 5 °C / min and calcine for 4 h to obtain the yttrium modified support.
[0035] Dissolve 1.47 g chloroplatinic acid (H2PtCl6) in 50 mL deionized water, stir until completely dissolved to prepare a chloroplatinic acid impregnation solution, and uniformly impregnate the yttrium modified support with the solution to ensure sufficient adsorption of the solution. Dry the impregnated support in a 100 °C oven for 8 h, and then calcine at 500 °C for 4 h to obtain catalyst B.
[0036] Example 3:
[0037] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0038] Add 300 g pseudoboehmite, 100 g ceria-zirconia solid solution, and 100 g SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the materials. Slowly add 200 mL of 3% (w / w) nitric acid aqueous solution and continue kneading for 20 min to form a uniform wet material. Transfer the wet material to an extruder for extrusion molding. After standing at room temperature for 12 h, place the material in a 100 °C oven for drying for 8 h, and then heat to 500 °C at 5 °C / min and calcine for 4 h to obtain the support.
[0039] Take 100 g of the carrier, dissolve 30.92 g of yttrium nitrate (Y(NO3)3) in 50 mL of deionized water, stir until completely dissolved to prepare a yttrium nitrate impregnation solution, impregnate an equal volume of the carrier with the yttrium nitrate impregnation solution, ensure that the solution is fully absorbed, dry in a 100°C oven for 8 h, and then heat to 500°C at a rate of 5°C / min and calcine for 4 h to obtain a yttrium-modified carrier.
[0040] Dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water, stir until completely dissolved to prepare a chloroplatinic acid impregnation solution, and uniformly impregnate the yttrium-modified carrier with the solution, ensuring that the solution is fully absorbed, dry in a 100°C oven for 8 h, and then calcine at 500°C for 4 h to obtain catalyst C.
[0041] Example 4:
[0042] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0043] Put 300 g of pseudoboehmite and 100 g of SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the materials, slowly add 200 mL of 3% (w / w) nitric acid solution, continue kneading for 20 min to form a uniform wet material, transfer to an extruder for extrusion molding, and then place in a 100°C oven to dry for 8 h, and then heat to 500°C at a rate of 5°C / min and calcine for 4 h to obtain a carrier.
[0044] Take 100 g of the carrier, dissolve 30.92 g of yttrium nitrate (Y(NO3)3) in 50 mL of deionized water, stir until completely dissolved to prepare a yttrium nitrate impregnation solution, impregnate an equal volume of the carrier with the yttrium nitrate impregnation solution, ensure that the solution is fully absorbed, dry in a 100°C oven for 8 h, and then heat to 500°C at a rate of 5°C / min and calcine for 4 h to obtain a yttrium-modified carrier.
[0045] Dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water, stir until completely dissolved to prepare a chloroplatinic acid impregnation solution, and uniformly impregnate the yttrium-modified carrier with the solution, ensuring that the solution is fully absorbed, dry in a 100°C oven for 8 h, and then calcine at 500°C for 4 h to obtain catalyst C.
[0046] Example 5:
[0047] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0048] Put 300 g of pseudo-boehmite into a kneader and mix for 20 min to ensure uniform dispersion of the material. Slowly add 200 mL of 3% (w / w) nitric acid solution and continue kneading for 20 min to form a uniform wet material. Transfer the material to an extruder and extrude into a shape. After standing at room temperature for 12 h, place the material in an oven at 100°C for 8 h, then increase the temperature to 500°C at a rate of 5°C / min and calcine for 4 h to obtain the carrier.
[0049] Take 100 g of the carrier and dissolve 23.19 g of yttrium nitrate (Y(NO3)3) in 50 mL of deionized water. Stir until completely dissolved to prepare a yttrium nitrate impregnation solution. Impregnate the carrier with an equal volume of the solution, ensuring that the solution is fully absorbed. Dry in an oven at 100°C for 8 h, then increase the temperature to 500°C at a rate of 5°C / min and calcine for 4 h to obtain the yttrium-modified carrier.
[0050] Dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water and stir until completely dissolved to prepare a chloroplatinic acid impregnation solution. Uniformly impregnate the yttrium-modified carrier with the solution, ensuring that the solution is fully absorbed. Dry in an oven at 100°C for 8 h, then calcine at 500°C for 4 h to obtain catalyst E.
[0051] Example 6:
[0052] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0053] Put 300 g of pseudo-boehmite, 100 g of cerium-zirconium solid solution, and 100 g of SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the material. Slowly add 200 mL of 3% (w / w) nitric acid solution and continue kneading for 20 min to form a uniform wet material. Transfer the material to an extruder and extrude into a shape. After standing at room temperature for 12 h, place the material in an oven at 100°C for 8 h, then increase the temperature to 500°C at a rate of 5°C / min and calcine for 4 h to obtain the carrier.
[0054] Take 100 g of the carrier and dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water. Stir until completely dissolved to prepare a chloroplatinic acid impregnation solution. Uniformly impregnate the carrier with the solution, ensuring that the solution is fully absorbed. Dry in an oven at 100°C for 8 h, then calcine at 500°C for 4 h to obtain catalyst F.
[0055] Example 7:
[0056] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0057] Put 300 g of pseudo-boehmite, 50 g of cerium-zirconium solid solution and 100 g of SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the materials, slowly add 200 mL of 3% (w / w) nitric acid aqueous solution, continue to knead for 20 min to form a uniform wet material, transfer to an extruder for extrusion molding, stand at room temperature for 12 h, then place in a 100 ℃ oven for drying for 8 h, then heat to 500 ℃ at a rate of 5 ℃ / min and calcine for 4 h to obtain the carrier.
[0058] Take 100 g of the carrier, dissolve 23.19 g of yttrium nitrate (Y(NO3)3) in 50 mL of deionized water, stir until completely dissolved to prepare a yttrium nitrate impregnation solution, and impregnate the carrier with an equal volume of the yttrium nitrate impregnation solution, ensuring that the solution is fully absorbed, dry in a 100 ℃ oven for 8 h, heat to 500 ℃ at a rate of 5 ℃ / min and calcine for 4 h to obtain the yttrium-modified carrier.
[0059] Dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water, stir until completely dissolved to prepare a chloroplatinic acid impregnation solution, and uniformly impregnate the yttrium-modified carrier with the solution, ensuring that the solution is fully absorbed, dry in a 100 ℃ oven for 8 h, and then calcine at 500 ℃ for 4 h to obtain catalyst G.
[0060] Example 8:
[0061] A method for preparing a catalyst for diesel isomerization and pour point depression, comprising the following steps:
[0062] Put 300 g of pseudo-boehmite, 150 g of cerium-zirconium solid solution and 100 g of SAPO-11 into a kneader and mix for 20 min to ensure uniform dispersion of the materials, slowly add 200 mL of 3% (w / w) nitric acid aqueous solution, continue to knead for 20 min to form a uniform wet material, transfer to an extruder for extrusion molding, stand at room temperature for 12 h, then place in a 100 ℃ oven for drying for 8 h, then heat to 500 ℃ at a rate of 5 ℃ / min and calcine for 4 h to obtain the carrier.
[0063] Take 100 g of the carrier, dissolve 23.19 g of yttrium nitrate (Y(NO3)3) in 50 mL of deionized water, stir until completely dissolved to prepare a yttrium nitrate impregnation solution, and impregnate the carrier with an equal volume of the yttrium nitrate impregnation solution, ensuring that the solution is fully absorbed, dry in a 100 ℃ oven for 8 h, heat to 500 ℃ at a rate of 5 ℃ / min and calcine for 4 h to obtain the yttrium-modified carrier.
[0064] Dissolve 1.47 g of chloroplatinic acid (H2PtCl6) in 50 mL of deionized water, stir until completely dissolved to prepare a chloroplatinic acid impregnation solution, and uniformly impregnate the yttrium-modified carrier with the solution, ensuring that the solution is fully absorbed, dry in a 100 ℃ oven for 8 h, and then calcine at 500 ℃ for 4 h to obtain catalyst H.
[0065] Table 1 Catalyst properties
[0066] Catalyst Pt content, % CeZr solid solution content, % Y content, % Catalyst A 0.7 24 0.5 Catalyst B 0.7 24 0.75 Catalyst C 0.7 24 1.0 Catalyst D 0.7 - 0.75 Catalyst E 0.7 - 0.75 Catalyst F 0.7 24 0.75 Catalyst G 0.7 12 0.75 Catalyst H 0.7 36 0.75
[0067] Table 2 Catalyst performance
[0068] Catalyst Liquid phase yield, % C12 isomer yield, % Catalyst A 93.5 38.8 Catalyst B 97.8 45.6 Catalyst C 94.1 39.1 Catalyst D 88.5 31.3 Catalyst E 80.4 32.8 Catalyst F 91.3 38.6 Catalyst G 89.8 36.9 Catalyst H 91.5 39.1
[0069] In summary, catalyst B (0.7% Pt, 24% cerium-zirconium solid solution, 0.75% Y) performs best, with a liquid phase yield of 97.8% and a C12 isomerization yield of 45.6%, thanks to the moderate yttrium content and the cerium-zirconium solid solution synergistically optimizing the acid distribution and hydrogenation activity.
[0070] A, C (Y content 0.5%, 1.0%) have lower isomerization yields (38.8%, 39.1%), G, H (cerium-zirconium solid solution 12%, 36%) perform worse than B, D, E (no cerium-zirconium solid solution) have low yields (88.5%, 80.4%, 31.3%, 32.8%), E (no SAPO-11) is the worst, and F (no yttrium) has a yield of 91.3% and an isomerization yield of 38.6%. Catalyst B performs well in diesel isomerization and condensation, balancing high liquid phase yield and isomerization efficiency.
[0071] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a catalyst for isomerization and pour point depressing of diesel fuel, characterized in that, Includes the following steps: S1. Select boehmite, cerium-zirconium solid solution and silica-alumina molecular sieve, add them to a kneader and mix them. Slowly add acid solution and continue kneading to form a uniform wet material. Transfer it to an extruder to extrude and shape it. Let it stand at room temperature for curing, drying and calcining to obtain a carrier. S2. The prepared yttrium nitrate impregnation solution is uniformly impregnated onto the carrier in equal volume. After the impregnation solution is fully adsorbed, it is dried and calcined to obtain the yttrium modified carrier. S3. The prepared chloroplatinic acid impregnation solution is uniformly impregnated onto the yttrium-modified carrier in equal volume. After the impregnation solution is fully adsorbed, it is dried and calcined to obtain the final product.
2. The method for preparing a catalyst for isomerization and pour point depressing of diesel fuel according to claim 1, characterized in that, In S1, the mass ratio of pseudoboehmite, cerium-zirconium solid solution and silica-alumina molecular sieve is 3:1:
1.
3. The method for preparing a catalyst for isomerization and pour point depressing of diesel fuel according to claim 1, characterized in that, In step S1, the kneading time of the kneader is 15 to 20 minutes.
4. The method for preparing a catalyst for isomerization and pour point depressing of diesel fuel according to claim 1, characterized in that, In S1, the acid solution is a 3% (by mass) aqueous solution of nitric acid.
5. A method for preparing a catalyst for isomerization and pour point depressing of diesel fuel according to claim 1, characterized in that, In S1, the ratio of acid solution to boehmite is 100-200 mL: 150-300 g; The kneading process involving the addition of acid solution lasts for 15–20 minutes.
6. A method for preparing a catalyst for isomerization and pour point depressing of diesel fuel according to claim 1, characterized in that, In S1, the static conditioning time is 10-12 hours; Dry in an oven at 80–100℃ for 7–8 hours; then bake at 450–500℃ for 3.5–4 hours with the temperature increased at 5℃ / min.
7. The method for preparing a catalyst for isomerization dewaxing of diesel fuel according to claim 1, characterized in that, In step S2, yttrium nitrate and deionized water are mixed in a ratio of 14-30g:50mL to prepare a yttrium nitrate impregnation solution. Dry in an oven at 80–100℃ for 7–8 hours; then bake at 450–500℃ for 3.5–4 hours with the temperature increased at 5℃ / min.
8. A method for preparing a catalyst for isomerization dewaxing of diesel fuel according to claim 1, characterized in that, In step S3, chloroplatinic acid and deionized water are mixed in a ratio of 1-2 g: 50 mL to prepare a chloroplatinic acid impregnation solution. Dry in an oven at 80–100℃ for 7–8 hours; then bake at 450–500℃ for 3.5–4 hours with the temperature increased at 5℃ / min.
9. A catalyst for isomerization dewaxing of diesel fuel, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 8.
10. The application of a catalyst for diesel isomerization dewaxing as described in claim 9, characterized in that, The application of the catalyst in improving the low-temperature fluidity of diesel fuel.