Hydrogenation shape-selective cracking catalyst and application method thereof

Abstract

The invention relates to the technical field of petrochemical engineering catalysts, in particular to a hydrogenation shape-selective cracking catalyst and an application method thereof. The hydrogenation shape-selective cracking catalyst comprises a carrier and active metal components, the carrier comprises an SAPO-11 molecular sieve, a ZSM-23 molecular sieve and low-sodium small-pore pseudo-boehmite powder, and the active metal components comprise palladium, nickel, lanthanum and cerium; based on the total weight of the catalyst, the content of the SAPO-11 molecular sieve is 40 to 50 weight percent, the content of the ZSM-23 molecular sieve is 7 to 8.5 weight percent, the content of the palladium is 0.2 to 1.5 weight percent, the content of the nickel is 0.5 to 5.5 weight percent, the content of the cerium is 0.6 to 4 percent, the content of the lanthanum is 2 to 7 percent, and the balance is low-sodium small-pore pseudo-boehmite powder. According to the invention, transformer oil with a pour point of less than-50 DEG C and a high-quality bright oil product with a viscosity index of more than 110 and transparent and floccule-free at 15 DEG C can be produced.

Description

Technical Field

[0001] This invention relates to the field of petrochemical catalyst technology, specifically to hydroforming cracking catalysts and their application methods. Background Technology

[0002] As domestic enterprises accelerate their transformation towards low-carbon, environmentally friendly, and high-quality development, the demand for fuel oil, especially gasoline and diesel, is declining. Refining companies are generally facing demands and challenges related to the conversion of oil to specialty products and oil transformation. Transformer oil, light white oil, heat transfer oil, food-grade white oil, and 120BS and 150BS bright oils are some of the main representative products of specialty oils.

[0003] Bright stock is a high-viscosity lubricating oil base oil used under high-temperature or heavy-load conditions. It is used to adjust the high-temperature viscosity of lubricating oil products and is widely used in industrial oils such as gear oils, hydraulic oils, greases, and heavy internal combustion engine oils such as marine engine oils and high-grade multi-grade engine oils. Bright stock requires high viscosity, a high viscosity index, good oxidation stability, and low-temperature fluidity. With the upgrading of global lubricating oil product quality, the demand structure for base oils has changed significantly, and high-viscosity heavy base oils still have a large market. However, with the decreasing availability of high-quality crude oil resources and the diversification of crude oil sources, the high-quality resources for producing high-quality bright stock are becoming increasingly scarce, making it difficult for the production volume and quality of bright stock products to meet market demand. This is specifically reflected in performance indicators such as viscosity grade, viscosity index, and transparency without flocculent matter. For example, using naphthenic oil as a raw material, achieving a viscosity index of over 90 is challenging; for paraffinic oil as a raw material, the viscosity grade is also a challenge, with kinematic viscosity at 100°C often failing to reach 22 mmHg. 2 / s, according to the Q / SHPRD0731-2018HVI20 standard, cannot meet 120BS and 150BS, and there is also the problem of opacity of flocculent matter.

[0004] Chinese patent application CN106554820A, published on April 5, 2017, discloses a method for preparing lubricating oil base oil, comprising: dewaxing the feedstock oil in a dewaxing reaction zone to obtain a wax conversion oil, wherein the dewaxing reaction zone includes at least two catalyst beds containing an isomerization dewaxing catalyst and a catalytic dewaxing catalyst in sequence, wherein the catalytic dewaxing catalyst contains a support including a shape-selective cracking molecular sieve and an active metal element selected from ruthenium, rhodium, platinum and palladium supported on the support, and the shape-selective cracking molecular sieve includes at least one selected from ZSM-5, ZSM-8, ZSM-10, ZSM-11, ZSM-12, ZSM-35, ZSM-38 and ZSM-48; and hydrorefining and separating the wax conversion oil. This invention is claimed to be able to prepare low-pour-point lubricating oil base oil from feedstock oil with high n-alkane content while reducing the difficulty of dewaxing in the production of lubricating oil base oil, and simultaneously ensuring the yield of lubricating oil base oil. The patented method does not involve bright oil, and the preparation method and function of the catalytic dewaxing catalyst are unrelated to bright oil.

[0005] Chinese patent application CN104449841A, published on March 25, 2015, discloses a method for producing a low pour point, high viscosity bright oil. It discloses a method using naphthenic light deasphalting oil (pour point ≥ 0℃, kinematic viscosity ≥ 60 mmHg at 100℃). 2 Using crude oil as feedstock, hydroisomerization technology is employed to isomerize high-pour-point alkanes or cycloalkanes with long side chains into low-pour-point branched alkanes or cycloalkanes with branched chains, while retaining the lubricating oil fraction in the feedstock. This achieves increased production of low-pour-point (pour point ≤ -18℃) and high-viscosity (kinematic viscosity ≥ 28 mmHg at 100℃) crude oil. 2The purpose is to produce bright oil, co-produce high-quality naphtha and clean middle distillate oil; the mesoporous molecular sieve used in the hydroisomerization dewaxing catalyst is one or more of the following: ZSM-22 / ZSM-23 composite molecular sieve, ZSM-23 / ZSM-22 composite molecular sieve, ZSM-5 / SAPO-11 composite molecular sieve, ZSM-22 / SAPO-11 composite molecular sieve, and ZSM-23 / SAPO-11 composite molecular sieve. It is claimed to be flexible in operation, with high bright oil yield, low pour point, high viscosity, and high viscosity index. This patent mainly focuses on high viscosity, only mentioning a viscosity index of 92 in the examples. In fact, there is an inverse relationship between the increase in the viscosity index of oil products and the changes in viscosity and pour point. Molecules with fewer rings and more and longer side chains have higher viscosity indices, while those with more rings and fewer and shorter side chains have lower viscosity indices. Due to the inherent characteristics of naphthenic oils, the viscosity index of this patented raw material—naphthenic light deasphalting oil—is low, even close to zero, because it contains more cycloalkanes and aromatics. Deep hydrocracking can significantly increase its viscosity index, but it also results in a decrease in molecular weight, i.e., a decrease in viscosity (or viscosity loss), a rebound in pour point, and a loss in yield. In order to maintain the viscosity grade of bright oil products (kinematic viscosity at 100°C less than 26 mmHg), 2 Oils with a viscosity of / s are not considered bright oils, or their viscosity loss is limited, restricting the depth of hydrotreating and consequently limiting the potential increase in viscosity index. Furthermore, for oils with a kinematic viscosity greater than 8mm at 100℃... 2 Heavy distillate oils, including bright oils, exhibit pour point rebound and are accompanied by flocculent formation problems that are difficult to resolve using isomerization pour point depressing processes and catalysts. Therefore, it is difficult to produce bright oils with a viscosity index above 90 using the above methods. A well-known domestic petrochemical company's two bright oil production lines, one using hydroponic pour point depressing and the other isomerization pour point depressing, use typical naphthenic oils as the main raw material, but no bright oil products with a viscosity index greater than 90 have been observed.

[0006] Chinese patent application CN110607191A, published on December 24, 2019, discloses a combined process for the hydrotreating of residual oil and the production of bright oil. This process first hydrotreates the residual oil, and then uses the hydrotreated tail oil as raw material to produce bright oil using traditional processes, which can significantly improve the product yield.

[0007] In summary, no optimizations or improvements have been found in the production technology of high-quality transformer oil and bright oil products. In particular, regarding the catalyst and supporting hydrogenation process, the "high-quality bright oil" referred to in this invention is defined as having a viscosity index greater than 110 and a kinematic viscosity ≥26 mmHg at 100°C. 2 Products with a pour point less than -15℃ and a transparent, flocculent consistency at 15℃. High-quality bright oils are used in lubricating greases in special industries such as aerospace and military, and have unique social and economic benefits. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a hydrocracking shape-selective cracking catalyst, coupled with isomerization dewaxing and post-refining catalysts, a hydrocracking process, and a product distillation system, to perform secondary hydrocracking on the heavy oil produced by hydrocracking, thereby producing high-quality bright oil and low-pour-point transformer oil.

[0009] Another objective of this invention is to provide a method for using a hydro-shape-selective cracking catalyst to prepare low-pour-point transformer oil and high-quality bright oil, which can produce transformer oil with a pour point of less than -50°C and high-quality bright oil products with a viscosity index greater than 110 and transparent and free of flocculent matter at 15°C.

[0010] This invention is achieved using the following technical solution:

[0011] The aforementioned hydroforming shape-selective cracking catalyst comprises a support and an active metal component. The support includes SAPO-11 molecular sieve, ZSM-23 molecular sieve, and low-sodium microporous pseudoboehmite powder. The active metal component includes palladium, nickel, lanthanum, and cerium. By total weight of the catalyst, the SAPO-11 molecular sieve content is 40–50 wt%, the ZSM-23 molecular sieve content is 7–8.5 wt%, the palladium content is 0.2–1.5 wt%, the nickel content is 0.5–5.5 wt%, the cerium content is 0.6–4%, the lanthanum content is 2–7%, and the remainder is low-sodium microporous pseudoboehmite powder. Furthermore, the sodium content in the catalyst, calculated as Na2O, is less than 600 ppm.

[0012] The catalyst contains 200–400 ppm sodium (calculated as Na2O).

[0013] The preparation method of the aforementioned hydroforming cracking catalyst includes the following steps: a. Low-sodium microporous pseudoboehmite powder, SAPO-11 molecular sieve and ZSM-23 molecular sieve are mixed in a mass ratio of 1:(0.5~2.0):(0.03~0.3), and after adding a binder, the mixture is shaped, dried and calcined to obtain a catalyst support; b. An active metal component containing palladium, nickel, lanthanum and cerium is loaded onto the support using an unsaturated impregnation method, and then dried and calcined to obtain an oxidized catalyst; c. The oxidized catalyst is reduced under H2 atmosphere to obtain the hydroforming cracking catalyst.

[0014] In step a, the water vapor concentration in the air atmosphere during carrier calcination is 5-20 v; preferably, 10-15 v; in step c, the volume ratio of H2 atmosphere to oxidized catalyst used for reduction is 300-800 v / v, and the H2O concentration in the H2 atmosphere is less than 100 ppmv.

[0015] The adhesive is preferably a kneading aid such as dilute nitric acid and / or gentian root powder.

[0016] Specifically, the preparation method of the hydroforming shape-selective cracking catalyst includes the following steps: Low-sodium microporous pseudoboehmite powder is uniformly mixed with SAPO-11 and ZSM-23 molecular sieves at a ratio of 1:0.5–2.0:0.03–0.3 (by mass), and an appropriate amount of binder is added and the mixture is rolled into shape. Then, it is dried at 60–120℃, -0.5 kPa–0.5 kPa, and in air for 4–6 hours, and calcined at 500–650℃, in air, and -0.5 kPa–0.5 kPa for 2–3 hours to obtain a catalyst support. The active metal component is loaded onto the catalyst support using an unsaturated impregnation method, and dried at 60–120℃, in air, and -0.5 kPa for 1–2 hours, and calcined at 450–600℃, in air, and -0.5 kPa–0.5 kPa for 1–2 hours to obtain an oxidized catalyst.

[0017] The oxidized catalyst was reduced at 150–550 °C, 0.5–5 MPa, and H2 atmosphere for 8–36 h to obtain the hydroforming cracking catalyst.

[0018] Specifically, the unsaturated impregnation method includes the following processing steps: First, prepare impregnation solutions of 40-45 wt% nickel nitrate aqueous solution, 4-5 wt% palladium dichloride aqueous solution, 20-25 wt% cerium nitrate aqueous solution, and 35-40 wt% lanthanum nitrate aqueous solution. Adjust the pH of the palladium dichloride aqueous solution to 2-3 with a small amount of hydrochloric acid and ammonia, and ensure that the ammonium chloride concentration does not exceed 3 wt%. Then, calculate the amount of each metal salt aqueous solution required per unit mass of catalyst support based on the metal content in the catalyst. Finally, spray and disperse each quantitative amount of aqueous solution onto the corresponding amount of support in the order of cerium nitrate, lanthanum nitrate, nickel nitrate, and palladium dichloride at room temperature and pressure. Spraying and dispersion are generally carried out intermittently in a coating pan.

[0019] The method for preparing low pour point transformer oil and high-quality bright oil using the aforementioned hydroforming cracking catalyst involves a secondary hydrogenation reaction of the hydrogenated heavy oil.

[0020] The secondary hydrogenation process is as follows: the hydrogenated heavy oil is mixed with hydrogen and then sequentially passed through a first hydrogenation reactor containing an isomerization dewaxing catalyst JRIW-1 and a hydroshape-selective cracking catalyst, and a second hydrogenation reactor containing a supplementary refining catalyst JRLF-20 to obtain the reaction products. The mass ratio of the catalysts used for isomerization dewaxing, hydroshape-selective cracking, and supplementary refining is 1:2:1.5.

[0021] Specifically, the secondary hydrogenation process for hydrogenation to produce heavy oil is as follows: the hydrogenated heavy oil is mixed with a hydrogen stream and heated to the reaction temperature, then sequentially fed into a first hydrogenation reactor and a second hydrogenation reactor for shape-selective cracking, olefin and aromatic saturation reactions, and isomerization products are separated by a separation system to obtain transformer oil and high-quality bright oil; preferably, heating and / or cooling equipment is provided between the first and second hydrogenation reactors; the first hydrogenation reactor contains 4 to 6 fixed-bed catalyst beds, with cold hydrogen injection between the beds to regulate the bed temperature distribution; preferably, the sulfur content in the hydrogen stream is less than 20 ppmv and the ammonia content is less than 5 ppmv.

[0022] The operating conditions for the first hydrogenation reactor are: reactor inlet temperature 300-370℃, hydrogen partial pressure 4-12MPa, and hydrogen-to-oil volume ratio (300-800):1; the operating conditions for the second hydrogenation reactor are: reactor inlet temperature 180-260℃, hydrogen partial pressure 4-12MPa, and hydrogen-to-oil volume ratio (300-800):1.

[0023] The first hydrogenation reactor has 4 to 6 beds, with cold hydrogen injection between the beds. The initial total pressure drop of the reactor beds is 30 to 100 kPa.

[0024] Both the first and second hydrogenation reactors are fixed-bed reactors, employing a top-feed and bottom-discharge trickle-bed reactor and process flow. They utilize a single-stage, series-connected, cold high-pressure separation, one-pass process. The isomerization reaction products flow out of the second hydrogenation reactor and are further separated by a separation system to obtain high-quality bright oil and other products. The separation system includes high-low pressure separation tanks, a butanizer tower, an isomerization atmospheric pressure tower, and an isomerization vacuum pressure tower.

[0025] The reaction products are fractionated by a separation system to obtain various lubricating oil base oil products, including transformer oil and bright oil. The transformer oil has a pour point less than -50℃, and the bright oil has a viscosity index greater than 110 and a kinematic viscosity at 100℃ ≥ 26 mm³ / s. 2 / s, pour point less than -15℃ and transparent without flocculation at 15℃.

[0026] The hydrogenated heavy oil is a heavy distillate oil that has undergone one hydrogenation treatment. Hydrogenated heavy oil refers to oil with a 2% distillation point temperature greater than 300℃, a 10% distillation point temperature greater than 365℃, a 50% distillation point temperature greater than 450℃, a 70% distillation point temperature greater than 505℃, and a kinematic viscosity of 4–7 mm at 100℃. 2 / s, BMCI value less than 10, pour point 31~35℃, wax viscosity index greater than 125, total sulfur less than 20ppm, total nitrogen less than 2ppm, water content less than 50ppm.

[0027] Using the aforementioned shape-selective cracking catalyst, along with isomerization dewaxing and post-refining catalysts, hydrogenation processes, and product distillation systems, the hydrogenated heavy oil can be hydrogenated a second time to produce low-pour-point transformer oil and high-quality bright oil.

[0028] Based on the production of heavy oil through hydrogenation, the transformer oil product specifications meet the requirements of GB2536-2011, with a preferred pour point of less than -50℃ and a kinematic viscosity of less than 2200 mmHg at -40℃. 2 / s, density 840~860kg / m³ 3 .

[0029] The high-quality bright oil mentioned above has a viscosity index greater than 110 and a kinematic viscosity at 100℃ ≥ 26 mm. 2 / s, products with a pour point less than -15℃ and transparent and free of fibrous matter at 15℃.

[0030] The determination of the cloud point in this invention is based on GB / T 6986-2014, "Determination of Cloud Point of Petroleum Products". The specific test conditions are as follows: place the sample in a standard test tube, cool it at a specified cooling rate, observe and record the temperature at which the sample begins to become cloudy; this temperature is the cloud point. The evaluation of 'transparent and free of flocculent matter at 15℃' can also refer to the regulations on the appearance inspection of bright oil in Q / SH PRD0731—2018, which states that the sample should be uniformly transparent and free of suspended or precipitated matter when visually tested at 15±2℃.

[0031] Existing heavy distillate isomerization dewaxing technology cannot fully convert long-chain macromolecular waxy residues, resulting in "flocculents" in the product. This is mainly because isomerization dewaxing catalysts lack the ability to achieve both high selectivity and high product yield. Uneven radial distribution of the reactant bed, and even slight channeling, also contribute to the formation of flocculents. This invention provides a shape-selective cracking catalyst, a shape-selective cracking reactor, and a supporting method. The catalyst, enhanced with improved shape-selective cracking capabilities, further cracks the waxy residues in the isomerization dewaxing reaction products. By controlling the molecular sieve of the catalyst and the low Na content of the high-purity, low-sodium microporous pseudoboehmite, the acid strength and shape-selective cracking activity of the active sites are improved.

[0032] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention provides a shape-selective cracking catalyst, which is matched with an isomerization dewaxing and post-refining catalyst, a hydrogenation process and a product distillation system to perform secondary hydrogenation on the hydrogenated heavy oil, thereby producing low pour point transformer oil and high-quality bright oil.

[0033] (2) The low pour point transformer oil refers to oil with a pour point of less than -50℃ and a kinematic viscosity of less than 2200 mmHg at -40℃. 2 / s, density 840~860kg / m³ 3Products.

[0034] (3) The high-quality bright oil has a viscosity index greater than 110 and a kinematic viscosity at 100℃ ≥ 26 mm. 2 A product with a pour point less than -15℃ and transparent and free of fibrous material at 15℃. Currently, no product has been found that simultaneously meets these specifications based on literature reports and market feedback. This high-quality brightener has special significance for applications in industries such as aerospace and military. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the apparatus for using the hydro-shape-selective cracking catalyst of the present invention to prepare low pour point transformer oil and high-quality bright oil. In the diagram: 1. Hydrogenation to produce heavy oil; 2. Hydrogen stream; 3. Effluent from the first hydrogenation reactor; 4. Feed to the second hydrogenation reactor; 5. Outlet of the second hydrogenation reactor; 6. Heterogeneous circulating hydrogen and high / low pressure flash separation and stripping fractionation of light hydrocarbons; 7. Feed inlet of the heterogeneous atmospheric distillation tower; 8. Naphtha outlet from the top of the heterogeneous atmospheric distillation tower; 9. Side stream oil outlet from the heterogeneous atmospheric distillation tower; 10. Bottom outlet of the heterogeneous atmospheric distillation tower; 11. Top outlet of the vacuum distillation tower; 12. Vacuum distillation line 1; 13. Vacuum distillation line 2; 14. Vacuum distillation line 3; 15. Vacuum distillation line 4; 16. Bottom outlet of the vacuum distillation tower; 17. First hydrogenation reactor; 18. Heating and / or heat removal equipment; 19. Second hydrogenation reactor; 20. Heterogeneous high / low pressure flash separation and stripping fractionation system; 21. Heterogeneous atmospheric distillation tower; 22. Heterogeneous vacuum distillation tower. Detailed Implementation

[0036] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below.

[0037] The apparatus used in the embodiments, such as Figure 1As shown, the hydrogenated heavy oil 1 is pressurized and mixed with hydrogen gas stream 2. After being heated to the reaction temperature by a heat exchanger and heater, it enters the first hydrogenation reactor 17 from the top. The effluent 3 from the first hydrogenation reactor is heated and / or cooled by a heat removal device 18 and used as feed 4 to the second hydrogenation reactor 19 from the top. The reaction product flows out from the bottom of the second hydrogenation reactor 19 through the outlet 5. After passing through a heat exchanger, cooling system, and a heterogeneous high / low pressure flash separation and stripping fractionation system 20, it is separated from the heterogeneous circulating hydrogen and light hydrocarbons through a high / low pressure flash separation and stripping fractionation system 6. The bottom oil of the stripping tower passes through the inlet 7 of the heterogeneous atmospheric pressure tower. The product is distilled in the heterogeneous atmospheric distillation tower 21. The top halide fraction is obtained at the top naphtha outlet 8 of the heterogeneous atmospheric distillation tower, and the atmospheric side-stream oil, i.e., light white oil component, is obtained at the side-stream oil outlet 9 of the heterogeneous atmospheric distillation tower. The bottom oil from the bottom outlet 10 of the heterogeneous atmospheric distillation tower enters the heterogeneous vacuum distillation tower 22 for further vacuum distillation to separate the products. The top oil (also a light white oil component, including the vacuum system, omitted in this figure) is obtained through the top outlet 11 of the vacuum distillation tower, the first line 12 (also a light white oil component), the second line 13 (transformer oil fraction, etc.), the third line 14 (No. 4 base oil fraction, etc.), the fourth line 15 (No. 6 base oil fraction, etc.), and the bottom oil (No. 10 or bright oil fraction from the bottom outlet 16 of the vacuum distillation tower, etc. The process flow description simplifies or omits related equipment and processes such as the fresh hydrogen replenishment system, pumps, compressors, heat exchangers, coolers, air coolers, heaters, and side-stream stripping towers. A heating and / or cooling device 18 is installed between the first hydrogenation reactor 17 and the second hydrogenation reactor 19. The first hydrogenation reactor 17 contains 3 to 6 fixed-bed catalyst beds, with cold hydrogen injection between the beds to regulate the temperature distribution. To highlight key aspects, the process flow description simplifies or omits related equipment and processes such as the fresh hydrogen replenishment system, pumps, compressors, heat exchangers, coolers, air coolers, heaters, and side-stream stripping towers.

[0038] Among them, the top oil is also a light white oil component (including the vacuum system, which is omitted in this figure); the first line 12 is also a light white oil component; the second line 13 is the transformer oil fraction, etc.; the third line 14 is the No. 4 base oil fraction, etc.; the fourth line 15 is the No. 6 base oil fraction, etc.; the bottom oil is the No. 10 or bright oil fraction.

[0039] This invention provides a hydroforming cracking catalyst: The catalyst consists of a support comprising SAPO-11 and ZSM-23 molecular sieves and low-sodium microporous pseudoboehmite powder, and active metals palladium, nickel, lanthanum (La), and cerium (Ce). Specifically, the catalyst contains 40–50 wt% SAPO-11 molecular sieve, 7–8.5 wt% ZSM-23 molecular sieve, 0.2–1.5 wt% palladium, 0.5–5.5 wt% nickel, 0.6–4% cerium, 2–7% lanthanum, and 35–65 wt% low-sodium microporous pseudoboehmite powder. The Na content (calculated as Na₂O) in the catalyst is less than 600 ppm.

[0040] Using the aforementioned shape-selective cracking catalyst, along with isomerization dewaxing and post-refining catalysts, hydrogenation processes, and a product distillation system, the hydrogenated heavy oil can be hydrogenated a second time to produce low-pour-point transformer oil and high-quality bright oil.

[0041] The transformer oil product specifications meet the requirements of GB2536-2011, preferably with a pour point of less than -50℃ and a kinematic viscosity of less than 2200 mmHg at -40℃. 2 / s, density 840~860kg / m³ 3 .

[0042] The high-quality bright oil has a viscosity index greater than 110 and a kinematic viscosity ≥26 mm at 100℃. 2 / s, products with a pour point less than -15℃ and transparent and free of fibrous matter at 15℃.

[0043] Hydrogenation produces heavy oils that have a 2% distillation temperature greater than 300℃, a 10% distillation temperature greater than 365℃, a 50% distillation temperature greater than 450℃, a 70% distillation temperature greater than 505℃, and a kinematic viscosity of 4–7 mm at 100℃. 2 / s, BMCI value less than 10, pour point 31~35℃, wax viscosity index greater than 125, total sulfur less than 20ppm, total nitrogen less than 2ppm, water content less than 50ppm; The preparation method of the hydro-shape-selective cracking catalyst includes the following steps: low-sodium microporous pseudoboehmite powder is uniformly mixed with SAPO-11 and ZSM-23 molecular sieves at a ratio of 1:0.5~2.0:0.03~0.3 (by mass), and an appropriate amount of binder is added and the mixture is rolled into shape. Then, it is dried at 60~120℃, -0.5kPa~0.5kPa and air atmosphere for 4h~6h, and calcined at 500~650℃, air atmosphere and -0.5kPa~0.5kPa for 2h~3h to obtain a catalyst support. The active metal component is loaded onto the catalyst support by unsaturated impregnation method, and dried at 60~120℃, air atmosphere and -0.5kPa~0.5kPa for 1h~2h, and calcined at 450~600℃, air atmosphere and -0.5kPa~0.5kPa for 1h~2h to obtain an oxidized catalyst.

[0044] The water vapor concentration in the carrier calcination air atmosphere is maintained at 5–20 v; preferably, 10–15 v.

[0045] The oxidized catalyst is reduced at 150–550 °C, 0.5–5 MPa, and in an H2 atmosphere for 8–36 h to obtain the hydroforming shape-selective cracking catalyst. The Na content in the catalyst, calculated as Na2O, is less than 600 ppm, preferably 200–400 ppm. The volume ratio of the H2 atmosphere to the oxidized catalyst is 300–800 v / v, and the H2 atmosphere composition is: H2 concentration of 80–99 v%, the remainder being N2, wherein the H2O concentration is less than 100 ppmv.

[0046] Using the aforementioned shape-selective cracking catalyst, coupled with isomerization dewaxing and post-refining catalysts, a hydrogenation process, and a product distillation system, the main process for secondary hydrogenation of the hydrogenated heavy oil to produce high-quality bright oil is as follows: the hydrogenated heavy oil is mixed with a hydrogen stream and heated to the reaction temperature, then sequentially fed into the first hydrogenation reactor 17 and the second hydrogenation reactor 19 for isomerization dewaxing, shape-selective cracking, and olefin and aromatic saturation reactions. The isomerization reaction products are separated by a separation system to obtain high-quality bright oil and other products. A heating and / or cooling device 18 is provided between the first hydrogenation reactor 17 and the second hydrogenation reactor 19; the first hydrogenation reactor 17 contains 3 to 6 fixed-bed catalyst beds, with cold hydrogen injection between the beds to regulate the bed temperature distribution; the sulfur content in the hydrogen stream is less than 20 ppmv, and the ammonia content is less than 5 ppmv.

[0047] Except for the shape-selective cracking catalyst, which is provided by the method of this patent, the catalysts used in the secondary hydrogenation are all commercially available products, including the isomer dewaxing catalyst and the supplementary refining catalyst.

[0048] Both the first hydrogenation reactor 17 and the second hydrogenation reactor 19 are fixed-bed reactors, adopting a trickle-bed reactor and process with top feed and bottom discharge. The isomer dewaxing catalyst is located above, in front of or upstream of the shape-selective cracking catalyst, and the shape-selective cracking catalyst is located above, in front of or upstream of the supplementary refining catalyst. The process adopts a one-stage, i.e., reactor series, cold high-speed separation, one-pass process. The products of the isomerization cracking reaction flow out from the bottom of the second hydrogenation reactor 19 and are further separated by a separation system to obtain high-quality bright oil and other products. The separation system includes high and low pressure separation tanks, a butane removal tower, an isomerization atmospheric pressure tower 21, and an isomerization vacuum tower 22. The isomerization vacuum tower 22 has four side streams for product extraction: Vacuum line 12 extracts light white oil fraction, Vacuum line 23 extracts transformer products, Vacuum line 34 extracts No. 4 base oil or heat transfer oil products, Vacuum line 45 extracts No. 6 base oil or No. 8 base oil or No. 68 industrial white oil products, and Vacuum line 45 extracts No. 10 base oil or No. 12 base oil or 120BS bright oil or 150BS bright oil or No. 100 industrial white oil products. The feed temperature of the isomerization vacuum tower 22 is less than 339℃, the pressure at the top of the tower does not exceed 2kPa, the pressure drop from the feed inlet to the top of the tower does not exceed 2kPa, and the pressure drop from the bottom of the tower to the feed inlet does not exceed 1kPa.

[0049] Secondary hydrogenation operating conditions: First hydrogenation reactor or bed inlet temperature: 300–370℃, hydrogen partial pressure: 4–12 MPa, hydrogen-to-oil volume ratio: (300–800):1; Second hydrogenation reactor or bed inlet temperature: 180–260℃, volume hourly space velocity: 1.0–2.0 h⁻¹ -1 .

[0050] Based on the production of heavy oil through hydrotreating, the product specifications meet the requirements of GB2536-2011, with a preferred pour point of less than -50℃ and a kinematic viscosity of less than 2200 mmHg at -40℃. 2 / s, density 840~860kg / m³ 3 .

[0051] When the existing hydroisomerization pour point depressing process is used to perform secondary hydrotreating on the hydrotreated heavy oil, the kinematic viscosity at 100°C is greater than 8 mm. 2 The heavier base oil products of / s all have the problem of flocculent matter, that is, the products have flocculent matter at 15°C and are not transparent. This problem is more prominent in bright oil products, which seriously affects the use and price of the products in some fields. Although there have been many reports on improvements such as adding or combining catalytic dewaxing catalyst beds, isomerizing pour point depressing catalysts or reactors, and increasing physical separation, such as patent CN106554820B.

[0052] The flocculent material in the product indicates that a small amount of waxy macromolecular fragments are present, and the isomerization dewaxing reaction is incomplete under current technical conditions, which may be related to the performance of the isomerization dewaxing catalyst.

[0053] The hydroforming cracking catalyst provided by this invention can achieve the full conversion of a small amount of waxy macromolecular residues, obtaining a qualified flocculent product while maintaining a high yield. The preparation method of the hydroforming cracking catalyst, especially the combination of active metals, the selection of molecular sieves in the support, and the control of Na content, improves the acid strength and shape-selective cracking activity of the active sites. The calcination treatment of the support is beneficial to improving the catalyst stability.

[0054] The present invention will be described in detail below through embodiments.

[0055] Example 1 The equipment for hydrogenation to produce heavy oil and secondary hydrogenation to produce high-quality bright oil is as follows: Figure 1 As shown, the apparatus includes: a first hydrogenation reactor 17 containing a heterogeneous dewaxing catalyst, a heating and / or heat removal device 18, a second hydrogenation reactor 19 containing a supplemental refining catalyst, a heterogeneous high and low pressure flash separation and stripping fractionation system 20, a heterogeneous atmospheric pressure tower 21, and a heterogeneous vacuum tower 22.

[0056] The first hydrogenation reactor 17 and the second hydrogenation reactor 19 are connected in series, with heating and / or heat removal equipment 18 and a cold hydrogen injection process between the reactors; a cold high-resolution process is adopted, and an independent sulfur-free circulating compressor is used.

[0057] The first hydrogenation reactor 17 is equipped with 6 catalyst beds, and a cold hydrogen injection process between the beds is used to regulate the temperature distribution of the beds.

[0058] Except for the hydro-shape-selective cracking catalyst, which uses JIC1 provided by the method of this patent, all catalysts used in the unit are commercially available products. Among them, the isomer dewaxing catalyst is JRIW-1 produced by Changling Branch of Sinopec Catalyst Co., Ltd., and the subsequent refining catalyst is JRLF-20 produced by Changling Branch of Sinopec Catalyst Co., Ltd.

[0059] The preparation method of the hydro-shape-selective cracking catalyst JIC1 includes the following main steps: ① According to the material ratio of low sodium microporous pseudoboehmite powder: SAPO-11 molecular sieve: ZSM-23 molecular sieve: 65% nitric acid aqueous solution: Tianqing powder = 100:110:20:6:4 (mass ratio), the low sodium microporous pseudoboehmite powder, etc. are mixed, kneaded, rolled and extruded into strips. The pseudoboehmite powder used was high-purity, low-sodium, small-pore pseudoboehmite from Jiangxi Baohong Nanotechnology Co., Ltd., with Na2O and Fe2O3 contents both less than 300 ppm (XRD / F test method). SAPO-11 and ZSM-23 molecular sieves from Qilu Branch of Sinopec Catalyst Co., Ltd. were used, with Na2O content both less than 500 ppm (XRD / F test method), a silica-alumina ratio of 25–50 (XRD / F test method), and a relative crystallinity greater than 80% (XRD / F test method). The catalyst support was then dried at 120℃, -0.3 kPa, and in air atmosphere for 4 hours, and calcined at 580℃, in air atmosphere, and -0.5 kPa for 2.5 hours, maintaining a water vapor concentration of 10 v% in the calcining air atmosphere. ② The active metal components were loaded onto the catalyst support using an unsaturated impregnation method. First, impregnation solutions for each metal salt were prepared, containing 40 wt% nickel nitrate aqueous solution, 5 wt% palladium dichloride aqueous solution, 25 wt% cerium nitrate aqueous solution, and 35 wt% lanthanum nitrate aqueous solution. The pH of the palladium dichloride aqueous solution was adjusted to 3 using hydrochloric acid and ammonia, and the ammonium chloride concentration did not exceed 3 wt%. Then, the required amounts of each impregnation solution were calculated based on the mass ratio of the target metal to the support (cerium 1:100, lanthanum 2:100, nickel 5:100, palladium 0.5:100). Finally, in a coating pan, the calculated amounts of each impregnation solution were intermittently sprayed onto the support in the order of cerium nitrate, lanthanum nitrate, nickel nitrate, and palladium dichloride, at room temperature and pressure to ensure uniform dispersion. The impregnated support was dried at 120℃ in air and at -0.5 kPa for 2 hours, and then calcined at 560℃ in air and at -0.5 kPa for 1.5 hours to obtain the oxidized catalyst. ③ The oxidized catalyst was reduced to JIC1 under a programmed temperature rise of 150-500℃, 1.0MPa, for 30h, and in an H2 atmosphere. The volume ratio of H2 atmosphere to oxidized catalyst was 500v / v. The composition of the H2 atmosphere was: H2 concentration greater than 90v%, with the remainder being nitrogen. Before reduction, the H2 atmosphere was dried to maintain an H2O concentration of less than 50ppmv.The nickel nitrate is commercially available nickel nitrate hexahydrate, with the following specifications: nickel nitrate hexahydrate content greater than 98.5 wt%, water-insoluble matter less than 0.01 wt%, cobalt less than 0.01 wt%, and alkali metals less than 0.01 wt%; palladium dichloride is purchased from the market according to GB / T8185-2020, with alkali metals less than 0.003 wt%; cerium nitrate is commercially available cerium nitrate hexahydrate, with the following specifications: cerium nitrate hexahydrate content greater than 99.9 wt%, water-insoluble matter less than 0.01 wt%, and alkali metals less than 0.01 wt%; lanthanum nitrate is lanthanum nitrate hexahydrate, with the following specifications: lanthanum nitrate hexahydrate content greater than 99.9%, water-insoluble matter less than 0.01 wt%, and alkali metals less than 0.01 wt%.

[0060] The final JIC1 hydroforming shape-selective cracking catalyst contained 4.7 wt% nickel (detected by X-ray fluorescence spectrometry), 0.46 wt% palladium (detected by X-ray fluorescence spectrometry), 2.2 wt% cerium (detected by X-ray fluorescence spectrometry), 3.7 wt% lanthanum (detected by X-ray fluorescence spectrometry), 43.34 wt% SAPO-11 molecular sieve, 7.55 wt% ZSM-23 molecular sieve, and the remainder was low-sodium microporous pseudoboehmite (approximately 38 wt%). The catalyst contained approximately 300 ppm Na (calculated as Na2O) and approximately 460 ppm Fe (calculated as Fe2O3).

[0061] Heavy oil produced by hydrotreating is used as raw material, and its properties are shown in Table 1. The operating conditions for hydrotreating, isomerization, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of low pour point transformer oil and high-quality bright oil are summarized in Table 3.

[0062] Example 2 Catalyst preparation: The preparation method of the hydroforming shape-selective cracking catalyst JIC2 is the same as in Example 1, except that the feed ratio is adjusted to achieve the following final composition: SAPO-11 molecular sieve: 47.12 wt% ZSM-23 molecular sieve: 8.26 wt%; Palladium (Pd): 0.2 wt% Nickel (Ni): 0.5 wt%; Cerium (Ce): 0.6 wt% Lanthanum (La): 2.0 wt% Low-sodium, small-pore pseudoboehmite powder: 41.32 wt%; Na2O content: <400ppm.

[0063] Secondary hydrogenation: Heavy oil produced by hydrogenation was used as the raw material, and the operating conditions were the same as in Example 1 (see Table 2). The yields and properties of the bright oil and transformer oil are shown in the reconstructed Table 3.

[0064] Example 3 Catalyst preparation: The preparation method of the hydroforming shape-selective cracking catalyst JIC3 is the same as in Example 1, except that the feed ratio is adjusted to achieve the following final composition: SAPO-11 molecular sieve: 40.0 wt% ZSM-23 molecular sieve: 7.0 wt% Palladium (Pd): 1.5 wt% Nickel (Ni): 5.5 wt% Cerium (Ce): 4.0 wt% Lanthanum (La): 7.0 wt% Low-sodium, small-pore pseudoboehmite powder: 35.0 wt%; Na2O content: <400ppm.

[0065] Secondary hydrogenation: Heavy oil produced by hydrogenation was used as the raw material, and the operating conditions were the same as in Example 1 (see Table 2). The yields and properties of the bright oil and transformer oil are shown in the reconstructed Table 3.

[0066] Comparative Example 1 The difference from Example 1 is that the secondary hydrogenation unit does not have a hydrogenation shape-selective cracking catalyst.

[0067] Heavy oil was produced by hydrotreating, and its properties are shown in Table 1. The operating conditions for hydroisomerization dewaxing, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of bright oil are summarized in Table 3.

[0068] Comparative Example 2 The difference from Example 1 is that the catalyst contains 0.47 wt% palladium metal, 48.5 wt% SAPO-11 molecular sieve, 8.5 wt% ZSM-23 molecular sieve, and the remainder is low-sodium microporous pseudoboehmite (approximately 43 wt%). The catalyst contains approximately 360 ppm Na (based on Na₂O) and approximately 530 ppm Fe (based on Fe₂O₃). The catalyst support calcination conditions are: 600°C, air atmosphere, -0.5 kPa, 2.5 h, with the water vapor concentration in the air atmosphere maintained at 10 v%. The resulting hydroforming cracking catalyst is JIC1A.

[0069] Heavy oil produced by hydrotreating is used as feedstock. Its properties are shown in Table 1. The operating conditions for hydrotreating isomerization pour point depressing, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of the bottom oil from the isomerization vacuum distillation tower are summarized in Table 3.

[0070] Comparative Example 3 The difference from Example 1 is that the catalyst contains 4.7 wt% nickel, 0.46 wt% palladium, and 3.7 wt% lanthanum (detected by X-ray fluorescence spectrometry), 44.43 wt% SAPO-11 molecular sieve, 7.74 wt% ZSM-23 molecular sieve, and the remainder is low-sodium microporous boehmite (approximately 39 wt%). The catalyst contains approximately 330 ppm Na (calculated as Na₂O) and approximately 500 ppm Fe (calculated as Fe₂O₃). The catalyst support calcination conditions are: 600°C, air atmosphere, -0.5 kPa, 2.5 h, with the water vapor concentration in the air atmosphere maintained at 10 wt%. The resulting hydroforming cracking catalyst is JIC1B.

[0071] Heavy oil produced by hydrotreating is used as feedstock. Its properties are shown in Table 1. The operating conditions for hydrotreating, isomerization, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of high-quality bright oil are summarized in Table 3.

[0072] Comparative Example 4 The difference from Example 1 is that the catalyst contains 4.7 wt% nickel, 0.46 wt% palladium, and 2.2 wt% cerium (detected by X-ray fluorescence spectrometry), 45.16 wt% SAPO-11 molecular sieve, 7.89 wt% ZSM-23 molecular sieve, and the remainder is low-sodium microporous boehmite (approximately 40 wt%). The catalyst contains approximately 330 ppm Na (calculated as Na₂O) and approximately 510 ppm Fe (calculated as Fe₂O₃). The catalyst support calcination conditions are: 600°C, air atmosphere, -0.5 kPa, 2.5 h, with the water vapor concentration in the air atmosphere maintained at 10 wt%. The resulting hydroforming cracking catalyst is JIC1C.

[0073] Heavy oil produced by hydrotreating is used as feedstock. Its properties are shown in Table 1. The operating conditions for hydrotreating, isomerization, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of high-quality bright oil are summarized in Table 3.

[0074] Comparative Example 5 The difference from Example 1 is that the catalyst contains 4.7 wt% nickel, 0.46 wt% palladium, 46.22 wt% SAPO-11 molecular sieve, 8.09 wt% ZSM-23 molecular sieve, and the remainder is low-sodium microporous pseudoboehmite (approximately 41 wt%). The catalyst contains approximately 330 ppm Na (based on Na₂O) and approximately 510 ppm Fe (based on Fe₂O₃). The catalyst support calcination conditions are: 600°C, air atmosphere, -0.5 kPa, 2.5 h, with the water vapor concentration in the air atmosphere maintained at 10 wt%. The resulting hydroforming cracking catalyst is JIC1D.

[0075] Heavy oil produced by hydrotreating is used as feedstock. Its properties are shown in Table 1. The operating conditions for hydrotreating, isomerization, shape-selective cracking, and supplementary refining are summarized in Table 2. The yield and properties of high-quality bright oil are summarized in Table 3.

[0076] The properties of heavy oil produced by hydrogenation in Examples 1-3 and Comparative Examples 1-5 are shown in Table 1.

[0077] The operating conditions for secondary hydrogenation Examples 1-3 and Comparative Examples 1-5 are shown in Table 2.

[0078] The test results of the gloss oil products of Examples 1-3 and Comparative Examples 1-5 are shown in Table 3.

[0079] The main components (wt%) of the hydroforming shape-selective cracking catalysts used in Examples 1-3 and Comparative Examples 1-5 are shown in Table 4.

[0080] Table 1: Properties of Heavy Oils Generated by Hydrogenation in Examples 1-3 and Comparative Examples 1-5

[0081] Table 2: Operating conditions of secondary hydrogenation examples 1-3 and comparative examples 1-5

[0082] Table 3: Test Results of Gloss Oil Products from Examples 1-3 and Comparative Examples 1-5

[0083] Table 4: Main components (wt%) of the hydroforming shape-selective cracking catalysts used in Examples 1-3 and Comparative Examples 1-5

[0084] As shown in Tables 3-4, all embodiments successfully produced "high-quality bright oil" with a viscosity index >110 and a cloud point as low as -5°C. Simultaneously, the transformer oil produced in conjunction with the invention also achieved a pour point below -50°C, demonstrating excellent performance. This fully achieved the invention's objective. Comparative Example 1, lacking the shape-selective cracking step, while having a acceptable pour point, had a viscosity index below the standard (105) and a cloud point as high as 43°C, exhibiting severe low-temperature turbidity and far from being a high-quality product. This proves that the added shape-selective cracking step in this invention is key to solving the flocculent problem. In Comparative Examples 3-5, the lack of Ce or La resulted in a decrease in the viscosity index and a sharp deterioration in the cloud point. The simultaneous lack of both Ce and La further degraded product performance. This clear trend of performance degradation irrefutably demonstrates that the synergistic effect of rare earth elements Ce and La is crucial for improving the viscosity index and completely eliminating flocculent matter. The hydroforming cracking catalyst containing specific rare earth metals proposed in this invention, combined with a matching secondary hydrotreating process, is a sufficient and necessary condition for producing high-quality bright oil that simultaneously meets the requirements of high viscosity index and extremely low cloud point.

Claims

1. A shape selective hydrocracking catalyst characterized in that, The catalyst comprises a carrier and an active metal component, the carrier comprises SAPO-11 molecular sieve, ZSM-23 molecular sieve and low-sodium small-pore pseudo-boehmite powder, and the active metal component comprises palladium, nickel, lanthanum and cerium; the SAPO-11 molecular sieve content is 40-50 wt%, the ZSM-23 molecular sieve content is 7-8.5 wt%, the palladium content is 0.2-1.5 wt%, the nickel content is 0.5-5.5 wt%, the cerium content is 0.6-4%, the lanthanum content is 2-7%, and the rest is low-sodium small-pore pseudo-boehmite powder, based on the total weight of the catalyst; and the sodium content in the catalyst, calculated as Na2O, is less than 600 ppm.

2. The hydroisomerization shape selective cracking catalyst of claim 1, wherein, The sodium content in the catalyst, calculated as Na2O, is 200-400 ppm.

3. The hydroisomerization shape selective cracking catalyst of claim 1, wherein, The preparation method of the hydrogen-selective cracking catalyst comprises the following steps: a. mixing low-sodium small-pore pseudo-boehmite powder, SAPO-11 molecular sieve and ZSM-23 molecular sieve according to a mass ratio of 1: (0.5-2.0): (0.03-0.3), adding a binder, shaping, drying and calcining to obtain a catalyst carrier; b. loading the active metal component containing palladium, nickel, lanthanum and cerium onto the carrier by using an unsaturated impregnation method, drying and calcining to obtain an oxidation-state catalyst; c. reducing the oxidation-state catalyst in a H2 atmosphere to obtain the hydrogen-selective cracking catalyst.

4. The hydroisomerization shape selective cracking catalyst of claim 3, wherein, The water vapor concentration in the air atmosphere during the calcination of the carrier in step a is 5-20 v%; and the volume ratio of the H2 atmosphere to the oxidation-state catalyst in step c is 300-800 v / v, and the H2O concentration in the H2 atmosphere is less than 100 ppmv.

5. A method of using a shape selective hydrocracking catalyst, characterized by, The hydrogen-selective cracking catalyst according to any one of claims 1-4 is used for secondary hydrogenation reaction of hydrogenation-produced heavy oil.

6. The method of use of claim 5, wherein, The process of the secondary hydrogenation is as follows: the hydrogenation-produced heavy oil is mixed with hydrogen, and then sequentially passes through a first hydrogenation reactor loaded with an isomerization and condensation-reducing catalyst JRIW-1, the hydrogen-selective cracking catalyst, and a second hydrogenation reactor loaded with a supplemental refining catalyst JRLF-20.

7. The method of claim 6, wherein the step of applying is performed by a user. A heating or / and heat-removing device is arranged between the first hydrogenation reactor and the second hydrogenation reactor.

8. The method of claim 6, wherein the step of applying is performed by a user. The operating conditions of the first hydrogenation reactor are: reactor inlet temperature 300-370°C, hydrogen partial pressure 4-12 MPa, and the operating conditions of the second hydrogenation reactor are: reactor inlet temperature 180-260°C, volume space velocity 1.0-2.0 h -1 .

9. The method of claim 6, wherein the composition is applied to the skin of the user at least once a day. The reaction product is separated by a separation system to obtain various lubricating oil base products including transformer oil and bright stock, wherein the transformer oil has a pour point less than -50 DEG C, the bright stock has a viscosity index greater than 110 and a 100 DEG C kinematic viscosity greater than or equal to 26 mm 2 / s, a pour point less than -15 DEG C and is transparent and free of flocculation at 15 DEG C.

10. The method of claim 5, wherein, The heavy oil generated by the hydrogenation is heavy distillate oil after once hydrogenation treatment, the 2% point distillation temperature of the heavy oil generated by the hydrogenation is greater than 300℃, the 10% point distillation temperature is greater than 365℃, the 50% point distillation temperature is greater than 450℃, the 70% point distillation temperature is greater than 505℃, the 100℃ kinematic viscosity is 4-7mm 2 / s, the BMCI value is less than 10, the condensation point is 31-35℃, the wax-containing viscosity index is greater than 125, the total sulfur is less than 20ppm, the total nitrogen is less than 2ppm, and the water content is less than 50ppm.

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