A catalyst for reducing the pour point of lubricating oil base oil, and a method for preparing and using the same
By using a catalyst composed of hydrogen-form ZSM-22/ZSM-23 eutectic molecular sieve, macroporous alumina, and precious metals, the problem of poor cloud point reduction effect of lubricating oil base oil in the prior art has been solved, and the effects of improving liquid yield and reducing cloud point have been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-07-04
- Publication Date
- 2026-06-02
AI Technical Summary
Existing catalysts are not very effective in reducing the cloud point of lubricating oil base oils, especially in improving liquid yield and reducing cloud point.
A novel hydroisomerization catalyst was prepared by using hydrogen-form ZSM-22/ZSM-23 eutectic molecular sieve as the main acidic component, combined with macroporous alumina and noble metal active components, and forming a suitable acidic distribution and pore structure through a specific preparation method.
In hydroisomerization reactions, it improves isomerization selectivity, avoids hydrocracking of alkanes and excessive cracking of product molecules, increases liquid yield, and significantly reduces the cloud point of lubricating oil base oils.
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Figure CN117380261B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a catalyst for reducing the cloud point of lubricating oil base oil, its preparation method and application, and more specifically, to a hydroisomerization catalyst for reducing the cloud point of lubricating oil base oil, its preparation method and application. Background Technology
[0002] As a widely used chemical product, lubricating oil has long been a focus of research, with low-temperature fluidity being a crucial indicator of its quality. Typically, converting long-chain n-alkanes with poor low-temperature fluidity into branched isoalkanes can effectively improve viscosity index and yield, and lower the pour point of the lubricating oil base. Therefore, improving the isomerization process of n-alkanes has received increasing attention, and modifying hydroisomerization catalysts has remained a research hotspot.
[0003] Patent CN1352231A discloses a method for preparing a dewaxing catalyst. It uses ZSM-5 molecular sieve with a silica-to-alumina ratio of 40-70. The sieve is extruded with binders and additives to form a support, which is then calcined at high temperature to further reduce the acid content. Subsequently, an active metal is introduced to obtain a highly selective cracking catalytic dewaxing agent. However, analysis of the results shows that this agent has only a moderate dewaxing effect on lubricating oil base oils.
[0004] To improve catalyst performance, researchers have combined multiple molecular sieves to prepare catalysts, achieving complementary advantages.
[0005] CN1762594A discloses an alkane hydroisomerization catalyst. The catalyst is prepared by combining various ten-membered ring one-dimensional porous molecular sieves such as ZSM-22, ZSM-23, SAPO-11, and EU-1. Due to the low content of weak and medium-strong acids in the molecular sieves, long-chain alkanes are broken down, resulting in a low base oil yield at a reaction temperature of 325℃.
[0006] CN108816279A discloses an isomerization dewaxing catalyst. It uses a series of ten-membered ring molecular sieves, including ZSM-22, ZSM-23, SAPO-11, EU-1, ZSM-48, and NU-10, as supports, and loads noble metals to prepare a n-alkane isomerization dewaxing catalyst. However, due to the low content of weak and moderately strong acids in the molecular sieves, the selectivity and yield of this catalyst for base oil remain low at 318℃. Summary of the Invention
[0007] To overcome the shortcomings of existing technologies, this invention provides a high-performance catalyst for producing low-cloud-point lubricating oil base oils, its preparation method, and its application. This catalyst contains a high content of weak acids and a suitable content of strong acids, which significantly reduces the cloud point of the lubricating oil base oil while improving liquid yield.
[0008] The first aspect of the present invention provides a catalyst for reducing the cloud point of lubricating oil base oil, the catalyst containing hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, wherein the mass content of ZSM-22 molecular sieve in the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve is 10~95%, preferably 15~90%.
[0009] The catalyst of this invention comprises the following components, based on the final weight of the catalyst:
[0010] a) Hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, with a content of 20~75wt%, preferably 25~70wt%;
[0011] b) Macroporous alumina, with a content of 25-80 wt%, preferably 30-75 wt%;
[0012] c) The active component of precious metal, in a content of 0.05 to 1.50 wt% as an element, preferably 0.08 to 1.00 wt%.
[0013] In the catalyst of the present invention, the total acid content of the catalyst is 0.09~0.30 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ is 65~87%; preferably, the total acid content is 0.11~0.28 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ is 67~85%.
[0014] In the catalyst of this invention, the specific surface area of the catalyst is 195~315 m². 2 / g, pore volume 0.46~0.80 cm³ 3 / g; preferably 200~305 m 2 / g, with a pore volume preferably between 0.51 and 0.76 cm³. 3 / g.
[0015] In the catalyst of the present invention, the noble metal active component is one or a combination of two of Re, Pt, Pd, Ru, and Rh, preferably one or more of Pt and Pd.
[0016] A second aspect of the present invention provides a method for preparing a catalyst for reducing the cloud point of lubricating oil base oil, the method comprising the following steps:
[0017] (1) Prepare hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, wherein the total acid content of the hydrogen-form ZSM-22 / ZSM-23 is 0.13~0.45 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ accounts for 55~85% of the total acid content; preferably, the total acid content is 0.15~0.43 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ accounts for 57~83% of the total acid content;
[0018] (2) The hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, macroporous alumina and binder prepared in step (1) are mixed, shaped, dried and calcined to obtain the carrier;
[0019] (3) Noble metal active components are introduced into the carrier obtained in step (2), and the final catalyst is obtained after drying and calcination.
[0020] In the method of the present invention, the relative crystallinity of the hydrogen-type ZSM-22 / ZSM-23 eutectic molecular sieve in step (1) is 95~110%, preferably 97~108%; after hydrothermal treatment at 600℃ for 2 hours, the relative crystallinity is 94~108%, preferably 95~105%.
[0021] In the method of this invention, the macroporous alumina described in step (2) has the following properties: specific surface area of 375~450 m². 2 / g, pore volume 0.74~1.15 cm³ 3 / g; preferably, specific surface area is 390~430 m² 2 / g, pore volume 0.78~1.10 cm³ 3 / g.
[0022] In the method of the present invention, the carrier in step (2) is dried and calcined using conventional methods, specifically as follows: the drying temperature is 60~130 ℃ and the time is 2~12 hours, preferably 80~120 ℃ for 4~8 hours; the calcination temperature is 500~600 ℃ and the time is 2~8 hours, preferably 530~570 ℃ for 3~6 hours.
[0023] In the method of the present invention, the noble metal active component in step (3) is one or a combination of two of Re, Pt, Pd, Ru and Rh, preferably one or more of Pt and Pd.
[0024] In the method of the present invention, the method of supporting precious metal in step (3) can adopt conventional supporting methods in the prior art, preferably the impregnation method. After impregnation, the carrier is dried at 80~120 ℃ for 4~7 hours and then calcined at 400~700 ℃ for 3~12 hours to obtain the final catalyst.
[0025] When the catalyst of this invention is used to lower the cloud point of lubricating oil base oil, the reaction conditions are as follows: reaction temperature 300~400 °C, total reaction pressure 8.0~15.0 MPa, and liquid hourly space velocity 0.5~3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 600:1 to 1500:1.
[0026] When the catalyst of this invention is used to produce lubricating oil base oil, it uses hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve with high weak acid content as the main acid component. The catalyst has low strong acid content, suitable distribution of acidic sites of different strengths, and good matching between pore structure and acid properties. Therefore, it can improve isomerization selectivity in the hydroisomerization reaction process, avoid hydrocracking of straight-chain alkanes and excessive cracking of product molecules, improve liquid yield and reduce product cloud point, and effectively improve the quality of lubricating oil base oil. Attached Figure Description
[0027] Figure 1 The XRD pattern of the HZSM-22 / ZSM-23 eutectic molecular sieve product synthesized in Example 1 of this invention is shown. Detailed Implementation
[0028] In this invention, the relative crystallinity of the molecular sieve was determined by X-ray powder diffraction (XRD). Specifically, the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve prepared in Comparative Example 1 was used as a benchmark with a crystallinity of 100%. The relative crystallinity of other samples was obtained by comparing with it.
[0029] The total acid content and the acid content below 350 °C were measured by NH3 temperature-programmed desorption (NH3-TPD), with the acid content corresponding to the desorption temperature of 120~500 °C being taken as the total acid content.
[0030] In this invention, wt% is the mass fraction and v% is the volume fraction.
[0031] In this invention, the preparation method of the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve is as follows:
[0032] (1) Prepare a mixture A containing a structure-directing agent, amorphous silicon-aluminum or amorphous silicon-aluminum precursor;
[0033] (2) Prepare a mixed solution B of silicon source and alkali source;
[0034] (3) Mix mixture A and mixture B thoroughly to obtain the final gel, and then obtain sodium-type ZSM-22 / ZSM-23 eutectic molecular sieve after dynamic crystallization, filtration, washing, drying and calcination.
[0035] (4) The molecular sieve obtained in (3) is subjected to ammonium exchange to obtain hydrogen-type ZSM-22 / ZSM-23 eutectic molecular sieve.
[0036] In step (1) of the above method, the structure directing agent (SDA) is a mixture of dimethylamine and diethylamine.
[0037] In step (1) of the above method, the molar ratio of the structure-directing agent (SDA) dimethylamine to diethylamine is 12~30, preferably 15~25.
[0038] In step (1) of the above method, the molar ratio of silicon (as silicon oxide) to aluminum (as aluminum oxide) in the mixed solution is 1: (0.10~0.85), preferably 1: (0.20~0.80); the molar ratio of aluminum (as aluminum oxide) to the structure directing agent is 1: (10~350), preferably 1: (15~300).
[0039] In step (1) of the above method, an amorphous silicon-aluminum precursor is prepared by carbonization, and then a structure-directing agent is added to the amorphous silicon-aluminum precursor to obtain a mixture A.
[0040] The specific preparation process of a non-limiting amorphous silicon-aluminum precursor in this embodiment of the invention is as follows: An aluminum source (preferably sodium aluminate) solution and a silicon-containing compound solution are prepared separately; the sodium aluminate solution is mixed with a portion of the silicon-containing compound solution, and CO2 gas is introduced to form a gel. When the volume of the introduced CO2 gas accounts for 50-100% of the total introduced volume, preferably 70-90%, the remaining portion of the silicon-containing compound solution is added, and optionally aged to obtain the amorphous silicon-aluminum precursor.
[0041] In the preparation process of the above-mentioned amorphous silicon-aluminum precursor, the remaining silicon-containing compound solution, calculated as silicon dioxide, accounts for 5 to 85 wt% of the total amount of silicon-containing compound solution added, calculated as silicon dioxide, preferably 30 to 70 wt%.
[0042] In the preparation process of the above-mentioned amorphous silicon-aluminum precursor, the gelation reaction temperature is 10~30 ℃, and the pH value after gelation is controlled to be 9~12.
[0043] In the preparation process of the above-mentioned amorphous silicon-aluminum precursor, the silicon-containing compound solution is water glass and / or sodium silicate solution.
[0044] In the above-mentioned preparation process of amorphous silicon-aluminum precursor, the concentration of the aluminum source solution is 15~60 g Al2O3 / L based on the mass of Al2O3, the concentration of the silicon-containing compound solution is 40~260 g SiO2 / L based on the mass of SiO2, and the concentration of the CO2 gas is 30~60 g.
[0045] In the preparation process of the above-mentioned amorphous silicon-aluminum precursor, the aging time is 5-60 minutes, preferably 10-30 minutes; the aging temperature is 10-40 ℃, preferably 15-35 ℃.
[0046] In step (1) of the above method, the mixed solution A is stirred at 10~25 ℃ for 1~6 hours, preferably at 15~20 ℃ for 2~4 hours.
[0047] In step (2) of the above method, when preparing the mixed solution B, the alkali source is first dissolved in a small amount of water, and then a supplementary silicon source is added to it. The amounts of alkali source, deionized water, and supplementary silicon source are based on the aluminum (calculated as alumina) in the mixed solution in step (1), and the total feed molar ratio is SiO2 : Al2O3 : R2O (alkali source) : H2O = 1 : (0.005~0.025) : (0.015~0.08) : (40~80), SDA / SiO2 = 0.30~1.5. The preferred ratio is SiO2 / Al2O3 = 50~180, H2O / SiO2 = 30~60, R2O / SiO2 = 0.02~0.05, and SDA / SiO2 = 0.30~1.2.
[0048] In step (2) of the above method, the supplementary silicon source is one or more of silica sol, tetraethyl orthosilicate, water glass or fumed silica, preferably silica sol; the alkaline source is sodium hydroxide or / and potassium hydroxide.
[0049] In step (3) of the above method, the crystallization conditions are: dynamic crystallization at 150~200 ℃ for 16~84 hours, with a rotation speed of 10~60 rpm; preferably, dynamic crystallization at 160~180 ℃ for 20~72 hours, with a rotation speed of 20~40 rpm; drying temperature at 60~120 ℃ for 2~12 hours, preferably drying at 80~120 ℃ for 4~8 hours; calcination temperature at 500~600 ℃ for 2~8 hours, preferably calcination at 530~570 ℃ for 3~6 hours.
[0050] In step (4) of the above method, ammonium exchange is carried out using conventional methods, such as one or more ammonium exchanges. The Na in the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve after ammonium exchange is... + The content is less than 0.1%; then it can be washed, dried and roasted, wherein the drying temperature is 60~130 ℃ and the time is 2~12 hours, preferably drying at 80~120 ℃ for 4~8 hours; the roasting temperature is 500~600 ℃ and the time is 2~8 hours, preferably roasting at 530~570 ℃ for 3~6 hours.
[0051] In the preparation method of sodium-type ZSM-22 / ZSM-23 eutectic molecular sieve provided by this invention, all the aluminum source required for synthesis is added when preparing the amorphous silica-alumina precursor, which promotes the generation of the primary structural unit of the molecular sieve. When two structure-directing agents are added to the amorphous silica-alumina precursor, the two structure-directing agents preferentially chelate with Al species in the primary structural unit, and then, under their synergistic guiding effect, the pre-assembly of the TON / MTT composite topology is achieved. At the same time, the binding sites of Al atoms can be better controlled, promoting the subsequent crystallization to generate a molecular sieve with more weak acid sites. When a silicon source is added to form the final gel, sodium-type ZSM-22 / ZSM-23 eutectic molecular sieve is generated through dynamic crystallization. This molecular sieve has a high acid content below 350℃, which is a high proportion of the total acid content, and has great application prospects in the field of catalysis.
[0052] To better illustrate the present invention, the following description, in conjunction with embodiments and comparative examples, further explains the invention. However, the scope of the present invention is not limited to the scope of these embodiments.
[0053] Example 1
[0054] (1) Preparation of hydrogen-form eutectic molecular sieves
[0055] Prepare a 40 g Al2O3 / L sodium aluminate working solution. Take a sodium silicate solution containing 28 wt% SiO2 and dilute it to a 100 g SiO2 / L sodium silicate working solution. Place 150 mL of the sodium aluminate working solution in a gelation tank, then add 50 mL of the sodium silicate working solution. Control the reaction temperature at 20 °C and introduce CO2 gas at a concentration of 50 v%. When the pH value reaches 10.0, stop introducing CO2 and add another 90 mL of the sodium silicate working solution. Then, aerate and stabilize for 15 minutes to obtain an amorphous silica-alumina precursor. Add dimethylamine and diethylamine to the amorphous silica-alumina precursor obtained above, and stir at 15 °C for 2.5 hours to obtain mixture A.
[0056] Dissolve sodium hydroxide in the remaining water, then add the required amount of silica sol (containing 28 wt% SiO2) dropwise, and stir until homogeneous to obtain mixture B;
[0057] After thoroughly mixing mixture A and mixture B, a gel with a final molar ratio of SiO2 : Al2O3 : Na2O : DMA : DEA : H2O = 1 : 0.01 : 0.04 : 0.4 : 0.02 : 50 was obtained. The resulting gel was transferred to a stainless steel reactor and dynamically crystallized at 160 ℃ and 30 rpm for 48 hours. After crystallization, the gel was filtered, washed until neutral, dried at 100 ℃ for 6 hours, and calcined in air at 550 ℃ for 3 hours to obtain product Z-1.
[0058] A certain amount of Z-1 sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. The solution was stirred continuously in a water bath at 80–90 °C for 1 hour, then filtered and washed. This process was repeated twice. The sample was then dried in a 100 °C oven for 8 hours and calcined in air at 550 °C for 3 hours to obtain HZ-1. Its XRD pattern is shown below. Figure 1 As shown, the specific properties are shown in Table 1.
[0059] (2) Catalyst preparation
[0060] Macroporous alumina (specific surface area 423 m²), accounting for 29.3% of the catalyst weight, was used. 2 / g, pore volume 1.01 cm 3 A mixture of 70% HZ-1 molecular sieve (70%), 1% guar gum powder (1% by weight of the total weight of alumina and HZ-1 molecular sieve), and 1% nitric acid aqueous solution (1% by weight) was formed into a paste and extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.7 wt% by weight of catalyst) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst C-1. Specific properties are shown in Table 2.
[0061] Example 2
[0062] (1) Preparation of hydrogen-form eutectic molecular sieves
[0063] Prepare a 40 g Al2O3 / L sodium aluminate working solution. Take a sodium silicate solution containing 28 wt% SiO2 and dilute it to a 150 g SiO2 / L sodium silicate working solution. Place 200 mL of the sodium aluminate working solution in a gelation tank, then add 40 mL of the sodium silicate working solution. Control the reaction temperature at 25 °C and introduce CO2 gas at a concentration of 50 wt%. When the pH value reaches 10.5, stop introducing CO2 and add another 40 mL of the sodium silicate working solution. Then, allow the mixture to stabilize for 20 minutes to obtain an amorphous silica-alumina precursor. Add dimethylamine and diethylamine to the amorphous silica-alumina precursor obtained above and stir at 10 °C for 4 hours to obtain mixture A.
[0064] Dissolve sodium hydroxide in the remaining water, then add the required amount of silica sol (containing 28 wt% SiO2) dropwise, and stir until homogeneous to obtain mixture B;
[0065] After thoroughly mixing mixture A and mixture B, a gel with a final molar ratio of SiO2 : Al2O3 : Na2O : DMA : DEA : H2O = 1 : 0.02 : 0.02 : 1.0 : 0.04 : 50 was obtained. The resulting gel was transferred to a stainless steel reactor and dynamically crystallized at 180 ℃ and 30 rpm for 60 hours. After crystallization, the gel was filtered, washed until neutral, dried at 100 ℃ for 6 hours, and calcined in air at 550 ℃ for 6 hours to obtain product Z-2.
[0066] A certain amount of Z-2 sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. The mixture was stirred continuously in a water bath at 80–90 °C for 1 hour, then filtered and washed. This process was repeated twice. The sample was then dried in a 100 °C oven for 8 hours and calcined in air at 550 °C for 3 hours to obtain HZ-2. Its XRD pattern is similar to... Figure 1 Similarly, the specific properties are shown in Table 1.
[0067] (2) Catalyst preparation
[0068] Macroporous alumina (specific surface area 399 m²) accounting for 40% of the catalyst weight will be used. 2 / g, pore volume 0.93 cm³ 3 A mixture of 59.2% HZ-2 molecular sieve (alumina and HZ-2 molecular sieve), 1% guar gum powder (by weight of the total weight of alumina and HZ-2 molecular sieve), and 1% nitric acid aqueous solution (by weight) was prepared, water was added, and the mixture was pressed into a paste and extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.8 wt% of catalyst by weight) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst C-1. Specific properties are shown in Table 2.
[0069] Example 3
[0070] (1) Preparation of hydrogen-form eutectic molecular sieves
[0071] Prepare a 50 g Al2O3 / L sodium aluminate working solution. Take a sodium silicate solution containing 28 wt% SiO2 and dilute it to a 100 g SiO2 / L sodium silicate working solution. Place 200 mL of the sodium aluminate working solution in a gelation tank, then add 60 mL of the sodium silicate working solution. Control the reaction temperature at 30 °C and introduce 50 wt% CO2 gas. When the pH reaches 10.0, stop introducing CO2 and add another 40 mL of the sodium silicate working solution. Then, allow the mixture to stabilize for 30 minutes to obtain an amorphous silica-alumina precursor. Add dimethylamine and diethylamine to the amorphous silica-alumina precursor obtained above and stir at 20 °C for 2 hours to obtain mixture A.
[0072] Dissolve sodium hydroxide in the remaining water, then add the required amount of silica sol (containing 28 wt% SiO2) dropwise, and stir until homogeneous to obtain mixture B;
[0073] After thoroughly mixing mixture A and mixture B, a gel with a final molar ratio of SiO2 : Al2O3 : Na2O : DMA : DEA : H2O = 1 : 0.005 : 0.025 : 0.60 : 0.04 : 60 was obtained. The resulting gel was transferred to a stainless steel reactor and dynamically crystallized at 160 ℃ and 40 rpm for 24 hours. After crystallization, the gel was filtered, washed until neutral, dried at 100 ℃ for 6 hours, and calcined in air at 550 ℃ for 4 hours to obtain product Z-3.
[0074] A certain amount of Z-3 sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. The mixture was stirred continuously in a water bath at 80–90 °C for 1 hour, then filtered and washed. This process was repeated twice. The sample was then dried in an oven at 80 °C for 8 hours and calcined in air at 550 °C for 3 hours to obtain HZ-3. Its XRD pattern is similar to... Figure 1 Similarly, the specific properties are shown in Table 1.
[0075] (2) Catalyst preparation
[0076] Macroporous alumina (specific surface area 399 m²) accounting for 49.65% of the catalyst weight 2 / g, pore volume 0.93 cm³ 3A mixture of 50% HZ-3 molecular sieve (alumina and HZ-3 molecular sieve), 1% guar gum powder (by weight of the total weight of alumina and HZ-3 molecular sieve), and 1% nitric acid aqueous solution (by weight) was prepared, mixed with water, and pressed into a paste. The paste was then extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.35 wt% of catalyst by weight) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst C-3. Specific properties are shown in Table 2.
[0077] Example 4
[0078] (1) Preparation of hydrogen-form eutectic molecular sieves
[0079] Prepare a 40 g Al2O3 / L sodium aluminate working solution. Take a sodium silicate solution containing 28 wt% SiO2 and dilute it to a 50 g SiO2 / L sodium silicate working solution. Place 150 mL of the sodium aluminate working solution in a gelation tank, then add 140 mL of the sodium silicate working solution. Control the reaction temperature at 20 °C and introduce 50 wt% CO2 gas. When the pH reaches 10.0, stop introducing CO2 and add another 140 mL of the sodium silicate working solution. Then, aerate and stabilize for 20 minutes to obtain an amorphous silica-alumina precursor. Add dimethylamine and diethylamine to the amorphous silica-alumina precursor obtained above, and stir at 15 °C for 2 hours to obtain mixture A.
[0080] Dissolve sodium hydroxide in the remaining water, then add the required amount of silica sol (containing 28 wt% SiO2) dropwise, and stir until homogeneous to obtain mixture B;
[0081] After thoroughly mixing mixture A and mixture B, a gel with a final molar ratio of SiO2 : Al2O3 : Na2O : DMA : DEA : H2O = 1 : 0.01 : 0.04 : 0.5 : 0.02 : 50 was obtained. The resulting gel was transferred to a stainless steel reactor and dynamically crystallized at 180 ℃ and 30 rpm for 72 hours. After crystallization, the gel was filtered, washed until neutral, dried at 100 ℃ for 6 hours, and calcined in air at 550 ℃ for 3 hours to obtain product Z-4.
[0082] A certain amount of Z-4 sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. The solution was stirred continuously in a water bath at 80–90 °C for 1 hour, then filtered and washed. This process was repeated twice. The sample was then dried in a 100 °C oven for 8 hours and calcined in air at 550 °C for 3 hours to obtain HZ-4. Its XRD pattern is similar to... Figure 1 Similarly, the specific properties are shown in Table 1.
[0083] (2) Catalyst preparation
[0084] Macroporous alumina (specific surface area 392 m²), which accounts for 74.3% of the catalyst weight, 2 / g, pore volume 0.80 cm³ 3 A mixture of 25% HZ-4 molecular sieve (alumina and HZ-4 molecular sieve), 1% guar gum powder (1% by weight of the total weight of alumina and HZ-4 molecular sieve), and 1% nitric acid aqueous solution (1% by weight) was prepared, mixed with water, and pressed into a paste. The paste was then extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.7 wt% by weight of catalyst) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst C-4. Specific properties are shown in Table 2.
[0085] Comparative Example 1 (Refer to CN107416860B)
[0086] KOH and NaOH were added to deionized water and completely dissolved. Then, 1-methylbutylamine, methyl borate, and boric acid were added sequentially, and the mixture was stirred until completely dissolved. Finally, pentylamine and fumed silica were added sequentially to form an initial gel with a molar ratio of SiO2 : B2O3 : 1-methylbutylamine : pentylamine : OH. - Deionized water = 1 : 0.01 (molar ratio of potassium borate: boric acid = 3 : 1, based on B2O3) : 1.0 : 1.0 : 0.1 (molar ratio of KOH: NaOH = 1:1) : 70; 10 wt% all-silicon ZSM-22 as seed crystals (based on SiO2) was added to the obtained gel, and ultrasonically vibrated for 30 minutes at 50 ℃, 60 kHz frequency, and 1000 W ultrasonic power; the gel obtained after ultrasonication was transferred to a high-pressure microwave reactor and heated to 170 ℃ for crystallization for 1 hour. After filtration and washing until neutral, it was dried at 100 ℃ for 6 hours and calcined in air at 550 ℃ for 3 hours to obtain product DZ-1.
[0087] A certain amount of DZ-1 sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. After stirring continuously in a water bath at 80–90 °C for 1 hour, the sample was filtered and washed. The above operation was repeated twice. The sample was then dried in an oven at 100 °C for 8 hours and calcined in air at 550 °C for 3 hours to obtain H-DZ-1. The specific properties are shown in Table 1.
[0088] Macroporous alumina (specific surface area 423 m²), accounting for 29.3% of the catalyst weight, was used. 2 / g, pore volume 1.01 cm 3 A mixture of 70% H-DZ-1 molecular sieve (70%), 1% guar gum powder (1% of the total weight of alumina and H-DZ-1 molecular sieve), and 1% nitric acid aqueous solution (1% by weight) was prepared, mixed with water, and pressed into a paste. The paste was then extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.7 wt% by weight of catalyst) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst DC-1. Specific properties are shown in Table 2.
[0089] Comparative Example 2 (Refer to CN112479224A)
[0090] 0.247 g of NaOH was dissolved in 21.5 g of deionized water, and then 13.23 g of silica sol (containing 28 wt% SiO2) was added and mixed thoroughly to obtain gel A. 0.411 g of Al2(SO4)3·18H2O was dissolved in 20 g of deionized water to obtain solution B. Solution B was slowly added dropwise to gel A, and after stirring continuously for 30 minutes, dimethylamine and diethylamine were added. After stirring for 2 hours, an initial gel with a molar ratio of 1:0.01:0.05:0.72:0.03:45 was obtained. The obtained gel was transferred to a hydrothermal reactor and dynamically crystallized at 180 °C for 66 hours (40 rpm). After filtration and washing until neutral, it was dried at 100 °C for 6 hours and then at 550 °C. Product DZ-2 is obtained by roasting in air at ℃ for 3 hours.
[0091] A certain amount of DZ-2 molecular sieve sample was weighed and placed in a 2 mol / L ammonium nitrate solution with a liquid-to-solid ratio of 10. After stirring continuously in a water bath at 80–90 °C for 1 hour, the sample was filtered and washed. The above operation was repeated twice. The sample was then dried in an oven at 100 °C for 8 hours and calcined in air at 550 °C for 3 hours to obtain H-DZ-2. The specific properties are shown in Table 1.
[0092] Macroporous alumina (specific surface area 423 m²), accounting for 29.3% of the catalyst weight, was used. 2 / g, pore volume 1.01 cm 3 A mixture of 70% H-DZ-2 molecular sieve (70%), 1% guar gum powder (1% by weight of the total weight of alumina and H-DZ-2 molecular sieve), and 1% nitric acid aqueous solution (1% by weight) was prepared, mixed with water, and pressed into a paste. The paste was then extruded into strips. The extruded strips were dried at 120 °C for 4 hours and then calcined at 550 °C for 3 hours to obtain a support strip. Pt (0.7 wt% by weight of catalyst) was loaded onto the support strip using a conventional equal-volume impregnation method. The impregnation conditions were: adding a pre-prepared H2PtCl6 solution (equal to the water absorption of the support) and deionized water, allowing it to stand for 12 hours, drying it at 120 °C for 4 hours in air, and then calcining it at 450 °C for 4 hours to obtain catalyst DC-2. Specific properties are shown in Table 2.
[0093] Table 1
[0094]
[0095] Table 2
[0096]
[0097] The activity of the catalysts C-1, C-2, C-3, and C-4 of the present invention, and the comparative catalysts DC-1 and DC-2, were evaluated in a fixed-bed reactor. All catalysts were reduced in a hydrogen atmosphere at 400 °C for 4 hours before being used in the hydrogenation reaction to lower the cloud point of lubricating oil base oils. The specific reaction conditions were: reaction temperature 325 °C, pressure 12.0 MPa, and volumetric hourly space velocity 1.0 h⁻¹. -1 The hydrogen-to-oil ratio was 1000. The properties of the feedstock oil are shown in Table 3, and the reaction results are shown in Table 4.
[0098] As can be seen from the reaction results data in Table 4, compared with the catalyst prepared according to the prior art, under the same reaction conditions, the liquid yield increased by 1.7 to 2.2 percentage points and the cloud point of the product decreased by 9 to 13 °C after using the catalyst of the present invention.
[0099] Table 3 Properties of Crude Oil
[0100]
[0101] Table 4 Catalyst performance evaluation results
[0102]
Claims
1. The application of a catalyst in reducing the cloud point of lubricating oil base oil, characterized in that: The reaction conditions were: reaction temperature 300–400 °C, total reaction pressure 8.0–15.0 MPa, and liquid hourly space velocity 0.5–3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 600:1 to 1500:
1. The catalyst contains hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieves. The ZSM-22 molecular sieve content in the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve is 10% to 95% by mass. The total acid content of the catalyst is 0.09 to 0.30 mmol / g. The acid content corresponding to a desorption temperature below 350 ℃ in NH3-TPD is 65% to 87%. The relative crystallinity of the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve is 95% to 110%, and the relative crystallinity is 94% to 108% after hydrothermal treatment at 600 ℃ for 2 hours. Based on the final weight of the catalyst, it includes the following components: a) Hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, with a content of 20~75wt%; b) Macroporous alumina, content of 25~80 wt%; c) The active component of precious metals, in an elemental quantity of 0.05~1.50 wt%; the macroporous alumina has the following properties: specific surface area of 375~450 m². 2 / g, pore volume 0.74~1.15 cm³ 3 / g; the sum of the percentages of all components of the catalyst is 100%.
2. The application according to claim 1, characterized in that: Based on the final catalyst weight, it includes the following components: a) Hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, with a content of 25~70wt%; b) Macroporous alumina, with a content of 30~75 wt%; c) The active component of precious metals, in terms of elemental content, is 0.08~1.00 wt%; the sum of the percentages of all components in the catalyst is 100%.
3. The application according to claim 1, characterized in that: The total acid content of the catalyst is 0.11~0.28 mmol / g, and the acid content in NH3-TPD with a desorption temperature below 350 ℃ is 67~85%.
4. The application according to claim 1, characterized in that: The catalyst has a specific surface area of 195~315 m². 2 / g, pore volume 0.46~0.80 cm³ 3 / g.
5. The application according to claim 4, characterized in that: The catalyst has a specific surface area of 200~305 m². 2 / g, pore volume 0.51~0.76 cm³ 3 / g.
6. The application according to claim 1, characterized in that: The noble metal active component is one or a combination of two of Re, Pt, Pd, Ru, and Rh.
7. The application according to claim 6, characterized in that: The noble metal active component is one or both of Pt and Pd.
8. The application according to claim 6, characterized in that: The ZSM-22 molecular sieve content in the hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve is 15-90% by mass.
9. The application according to any one of claims 1-8, characterized in that: The method for preparing the catalyst includes the following steps: (1) Prepare hydrogen-form ZSM-22 / ZSM-23 eutectic molecular sieve, wherein the total acid content of the hydrogen-form ZSM-22 / ZSM-23 is 0.13~0.45 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ accounts for 55~85% of the total acid content; (2) The hydrogen-type ZSM-22 / ZSM-23 eutectic molecular sieve, macroporous alumina and binder prepared in step (1) are mixed, shaped, dried and calcined to obtain the carrier; (3) Noble metal active components are introduced into the carrier obtained in step (2), and the final catalyst is obtained after drying and calcination.
10. The application according to claim 9, characterized in that: In step (1), the total acid content of the hydrogen form ZSM-22 / ZSM-23 is 0.15~0.43 mmol / g, and the acid content corresponding to the desorption temperature of NH3-TPD below 350 ℃ accounts for 57~83% of the total acid content.
11. The application according to claim 9, characterized in that: The relative crystallinity of the hydrogen-type ZSM-22 / ZSM-23 eutectic molecular sieve in step (1) is 97~108%; after hydrothermal treatment at 600℃ for 2 hours, the relative crystallinity is 95~105%.
12. The application according to claim 9, characterized in that: The macroporous alumina described in step (2) has the following properties: specific surface area of 390~430 m². 2 / g, pore volume 0.78~1.10 cm³ 3 / g.
13. The application according to claim 9, characterized in that: The carrier described in step (2) is dried and calcined using conventional methods, specifically as follows: the drying temperature is 60~130 ℃ and the time is 2~12 hours; the calcination temperature is 500~600 ℃ and the time is 2~8 hours.
14. The application according to claim 13, characterized in that: The specific conditions for drying and calcining the carrier in step (2) are as follows: drying temperature is 80~120 ℃ and time is 4~8 hours; calcination temperature is 530~570 ℃ and time is 3~6 hours.
15. The application according to claim 9, characterized in that: In step (3), the precious metal loading method is impregnation. After impregnation, the carrier is dried at 80~120 ℃ for 4~7 hours and then calcined at 400~700 ℃ for 3~12 hours to obtain the final catalyst.