A method for producing lubricating oil base oil using waste plastic

Abstract

The application discloses a method for producing lubricating oil base oil by using waste plastics. The method comprises the following steps: mixing waste plastics with an organic solvent and heating to form a molten system, filtering to remove non-molten impurities, and then recycling the organic solvent, and the remaining part is molten waste plastic raw material; mixing the molten waste plastic raw material with hydroprocessed wax oil, and then entering a hydroisomerization dewaxing reactor with graded catalyst loading under a hydrogen environment, sequentially flowing through a protective agent layer and a catalyst layer to perform a hydroisomerization reaction, and obtaining a catalytic product, and then performing fractionation to obtain lubricating oil base oil. The method removes inorganic additives and inorganic impurities in the waste plastics through waste plastic pretreatment, and the protective agent and the catalyst are graded and loaded in the hydroisomerization dewaxing reactor, so that the waste plastics are maximally utilized to produce high-value low-tilt-point lubricating oil base oil.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petrochemical industry, and particularly relates to a method for producing lubricating oil base oil by using waste plastics. BACKGROUND

[0002] Plastic products bring convenience to people's life, but also cause increasingly serious pollution. The discarded plastics release some harmful substances in the long-term exposure and weathering, causing serious damage to the ecological environment, and also being a serious waste of petrochemical resources.

[0003] The existing waste plastic treatment technologies mainly include landfill, incineration, physical recycling and chemical recycling. Since the waste plastics have slow decomposition speed and low stacking density, landfill cannot fundamentally solve the problem and is easy to pollute groundwater resources. Incineration is easy to cause serious air pollution. Therefore, in order to reduce the pollution to the environment and realize the economic value of waste plastics, chemical recycling has become the main recycling means at present.

[0004] CN106520168A discloses a waste plastic treatment method. Inferior oil is mixed with waste plastics to perform a thermal cracking reaction. The obtained cracking gas is contacted with a catalyst to form a gas phase product and a liquid phase oil product. The liquid phase oil product is subjected to a hydrogenation treatment to form naphtha and diesel. The product generated by this process method has a relatively large amount of gas product, and the treatment of the gas product requires additional processes, resulting in high treatment cost.

[0005] CN101896582A discloses a waste plastic recycling method. Biomass is combined with waste plastics and Fischer-Tropsch wax to perform pyrolysis, and the obtained pyrolysis oil is subjected to fractionation. At least one fraction is subjected to a hydrogenation treatment, and at least one intermediate obtained after the hydrogenation treatment is subjected to catalytic isomerization to obtain an isomerization product. Since the waste plastics are not pretreated, a large amount of solid residues are generated in the pyrolysis device, which is easy to cause device blockage. In addition, a large amount of gas is generated, and it is difficult to recover and utilize the gas.

[0006] CN107987864A discloses a method and production device for preparing biomass oil and fuel gas from biomass and waste plastics. Biomass (wood fiber) and waste plastics are subjected to thermal cracking in a vacuum pyrolysis device to generate biomass oil and pyrolysis gas. This method can effectively improve the conversion efficiency of biomass and obtain more combustible mixed gas.

[0007] CN111363580A discloses a method for treating waste plastics by liquid phase hydrogenation process, waste plastics are subjected to hydrocracking through a liquid phase hydrogenation reactor, the obtained cracking products are subjected to liquid phase hydroisomerization reaction with at least one of paraffin-based distillate oil and Fischer-Tropsch wax to obtain lubricating oil base oil, diesel and hydrocarbon gas, and a certain amount of inorganic additives are contained in the waste plastics, and the waste plastics are lack of pretreatment work. SUMMARY

[0008] The present application aims to provide a method for producing lubricating oil base oil from waste plastics, which removes inorganic additives and inorganic impurities in waste plastics through waste plastic pretreatment, and simultaneously performs protective agent and catalyst grading loading in a hydroisomerization dewaxing reactor, so as to maximize the production of high value-added low pour point lubricating oil base oil from waste plastics.

[0009] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0010] A method for producing lubricating oil base oil from waste plastics, comprising the following steps:

[0011] Waste plastic pretreatment:

[0012] Mixing waste plastics with organic solvents and heating to melt all the meltable parts in the waste plastics to form a molten system; filtering the molten system to remove non-meltable impurities, and then recycling the organic solvents, and the remaining part is the meltable waste plastic raw material;

[0013] Production of lubricating oil base oil:

[0014] Mixing the meltable waste plastic raw material with the hydroprocessed wax oil, and then entering the hydroisomerization dewaxing reactor with graded loading under hydrogen environment, and sequentially flowing through the protective agent layer and the catalyst layer for hydroisomerization reaction to obtain a catalytic product; the catalytic product is subjected to fractionation to obtain lubricating oil base oil;

[0015] The protective agent layer is loaded with protective agent, and the catalyst layer is loaded with catalyst; along the material flow direction, the total acid amount of the catalyst first increases and then decreases, and the molar percentage content of the acid in the catalyst first increases and then decreases.

[0016] In the method for producing lubricating oil base oil from waste plastics, the waste plastics are pretreated by mixing with organic solvents and melting, and then filtering out inorganic additives and inorganic impurities; after filtration, the organic solvents in the molten system are subjected to flash evaporation recycling treatment, so that the organic solvents can be recycled and reused, and the molten system is subjected to filtering and impurity removal and solvent recycling treatment to obtain meltable waste plastic raw material.

[0017] ​Furthermore, the production method of this invention also utilizes a hydroisomerization dewaxing reactor with a specific gradation, by adjusting the number and intensity of acid centers in the catalyst (especially...) Acids can effectively regulate the distribution of catalytic product oils and the yield of base oils.

[0018] By rationally combining the protective agent layer and catalyst layer in the hydroisomerization dewaxing reactor, the acid content and distribution in the catalyst are optimized, thereby improving the overall catalytic efficiency of the protective agent and catalyst, and further reducing the low-temperature performance of the produced base oil. Because the acid content and distribution in the catalyst layer are rationally limited, the cracking performance of the oil is reduced, maximizing the hydroisomerization reaction and thus increasing the base oil yield. Furthermore, the method of this invention can also improve the viscosity index of the base oil.

[0019] According to the method of the present invention, preferably, the organic solvent is selected from at least one of pentane, cyclopentane, hexane, cyclohexane, octane, isooctane, heptane, benzene, toluene, xylene, and naphtha.

[0020] According to the method of the present invention, preferably, the mass ratio of the waste plastic to the organic solvent is 1:5 to 5:1.

[0021] According to the method of the present invention, preferably, waste plastic is crushed into granules and mixed with an organic solvent, and then heated to 100-200°C to melt it to form the melt system.

[0022] This invention employs a mixture of hydrotreated wax oil and fusible waste plastic raw materials for a hydroisomerization reaction. The hydrotreated wax oil has lower levels of sulfur, nitrogen, and metallic impurities, which helps the isomerization dewaxing catalyst maintain high activity over a long period and reduces the likelihood of catalyst deactivation. Preferably, the hydrotreated wax oil has a sulfur content ≤30 μg / g, a nitrogen content ≤15 μg / g, and a distillation range of 280–600℃, more preferably 300–560℃.

[0023] According to the method of the present invention, preferably, the mass ratio of the fusible waste plastic raw material to the hydrogenated wax oil is 2:(1-10).

[0024] According to the method of the present invention, preferably, the hydrotreated wax oil is selected from at least one of the following: hydrotreated negative 1 wax oil, hydrotreated negative 2 wax oil, hydrotreated negative 3 wax oil, hydrotreated negative 4 wax oil, and hydrocracking tail oil.

[0025] According to the method of the present invention, preferably, in the hydroisomerization reaction, the hydrogen-to-oil volume ratio is 200–800:1, the reaction temperature is 300–400°C, the reaction pressure is 6–15 MPa, and the volume hourly space velocity is 0.5–2.0 h⁻¹. -1More preferably, the hydrogen-to-oil volume ratio is 200–800:1, the reaction temperature is 320–380°C, the reaction pressure is 8–12 MPa, and the volume hourly space velocity is 0.8–1.5 h⁻¹. -1 .

[0026] In the graded-packed hydroisomerization dewaxing reactor of the present invention, preferably, the catalyst comprises an active metal and a support; based on the total mass of the catalyst, the mass percentage of the active metal is 0.1% to 1.0%, and the remainder is the support.

[0027] In the graded-filled hydroisomerization dewaxing reactor of the present invention, preferably, the active metal in the catalyst is selected from at least one of Pt, Pd, Ru, and Ni, more preferably Pt and / or Pd.

[0028] In the graded-packed hydroisomerization dewaxing reactor of the present invention, preferably, the support contains at least one molecular sieve with a ten-membered ring topology; more preferably, it further contains at least one amorphous inorganic porous material.

[0029] The molecular sieves include ZSM-5, SAPO-11, ZSM-22, ZSM-35, ZSM-23, ZSM-48, SAPO-41, etc.; the amorphous inorganic porous materials include alumina, silica, zirconium oxide, titanium oxide and their composite oxides, and the composite oxides include alumina-silica, zirconium oxide-silica, titanium oxide-silica, alumina-zirconia, zirconium oxide-titanium oxide, alumina-titanium oxide, etc.

[0030] In the hydroisomerization dewaxing reactor of the present invention, based on the total mass of the catalyst, the mass percentage of the molecular sieve is preferably 40% to 80%, more preferably 55% to 75%; and the mass percentage of the amorphous inorganic porous material is preferably 19% to 59.9%, more preferably 25% to 50%.

[0031] In this field, catalysts are classified into different types based on their ability to donate protons and accept electron pairs. Acids and Lewis acids. Among them, Acids, also known as proton acids, are defined using Brunsted's acid-base theory. Brunsted's acid-base theory defines an acid as a substance that can donate a proton; the stronger the ability to donate a proton, the stronger the acid. Lewis acids are defined using Lewis' acid-base theory. Lewis' acid-base theory defines an acid as a substance with empty orbitals that can accept electron pairs; the stronger the ability to accept electron pairs, the stronger the acid.

[0032] This invention allows for the determination of the catalyst's composition using pyridine infrared spectroscopy (Py-IR) characterization. The molar content of acids and Lewis acids, wherein pyridine is adsorbed on The acid center forms a pyridine ion, and the characteristic infrared absorption peak is in the range of 1530–1560 cm⁻¹. -1 The corresponding molar amount is The molar amount of acid; pyridine adsorbed at Lewis acid centers, with characteristic infrared absorption peaks in the range of 1440–1460 cm⁻¹. -1 The corresponding molar amount is the molar amount of Lewis acid. The molar percentage of acid refers to, based on The total molar amount of acids and Lewis acids Molar percentage of acid.

[0033] In this invention, the acids in the catalyst are classified into weak acids, moderately strong acids, and strong acids according to their acid strength. The content of weak acids refers to their molar content, the content of moderately strong acids refers to their molar content, the content of strong acids refers to their molar content, and the total acid content refers to the sum of the molar contents of weak, moderately strong, and strong acids. In some embodiments, the molar content of acids of various strengths and the total acid content in the catalyst can be determined using the ammonia-programmed temperature desorption (NH3-TPD) method. On the NH3-TPD desorption chart, the amount of ammonia desorbed between 100°C and 230°C corresponds to the amount of weak acids, the amount of ammonia desorbed between 230°C and 370°C corresponds to the amount of moderately strong acids, and the amount of ammonia desorbed above 370°C corresponds to the amount of strong acids. Specific operating methods may include: purging the catalyst sample with helium at 500℃ for 1 hour, then cooling to 60℃, introducing saturated ammonia vapor, and performing pulse adsorption five times to reach equilibrium; heating to 100℃ and purging for 2 hours, then performing ammonia desorption by programmed heating at a rate of 10℃ / minute, and heating to 650℃; absorbing the desorbed ammonia with hydrochloric acid solution, and then titrating the excess hydrochloric acid with sodium hydroxide solution, defining the amount of weak acid, medium-strong acid, strong acid, and total acid of the catalyst based on the amount of hydrochloric acid consumed in absorbing ammonia.

[0034] In the hydroisomerization dewaxing reactor of the present invention, preferably, the total acid content of the catalyst is 50-300 μmol / g, more preferably 100-300 μmol / g; the content of weak acid is 10-150 μmol / g, more preferably 20-100 μmol / g; and the content of medium-strong acid is 5-250 μmol / g, more preferably 10-220 μmol / g.

[0035] In the graded-packed hydroisomerization dewaxing reactor of the present invention, preferably, the catalyst contains... The molar percentage content of acid in the total acid content is 5% to 50%.

[0036] In the graded-filled hydroisomerization dewaxing reactor of the present invention, preferably, along the material flow direction, the catalyst layer comprises a first catalyst sublayer, a second catalyst sublayer, and a third catalyst sublayer that are sequentially adjacent to each other.

[0037] In the first catalyst sublayer, the content of weak acid is greater than the content of moderately strong acid; in the second catalyst sublayer, the content of weak acid is less than the content of moderately strong acid; in the third catalyst sublayer, the content of weak acid is less than the content of moderately strong acid.

[0038] Regarding the total acid content of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0039] Regarding catalysts The molar percentage content of acid in the total acid content, wherein the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer.

[0040] Preferably, the total acid content of the first catalyst sublayer is 50–200 μmol / g, the content of weak acids is 20–100 μmol / g, and the content of moderately strong acids is 10–80 μmol / g. The molar content of the acid is 5% to 20%. More preferably, the total acid content is 50 to 150 μmol / g, the weak acid content is 30 to 100 μmol / g, and the moderately strong acid content is 10 to 60 μmol / g. The molar content of acid is 5% to 15%;

[0041] The total acid content of the second catalyst sublayer is 150–300 μmol / g, the weak acid content is 30–100 μmol / g, and the medium-strong acid content is 120–200 μmol / g. The molar content of the acid is 20%–50%; more preferably, the total acid content is 200–300 μmol / g, the weak acid content is 50–100 μmol / g, and the moderately strong acid content is 150–200 μmol / g. The molar content of acid is 30% to 50%;

[0042] The total acid content of the third catalyst sublayer is 100–300 μmol / g, the content of weak acids is 20–100 μmol / g, and the content of moderately strong acids is 50–200 μmol / g. The molar content of the acid is 20%–50%; more preferably, the total acid content is 100–250 μmol / g, the content of weak acid is 20–80 μmol / g, and the content of moderately strong acid is 80–200 μmol / g. The molar content of acid is 25% to 50%.

[0043] It is understood that in this invention, the content of weak acid in the catalyst that first contacts the material is greater than the content of medium-strong acid, while the content of weak acid in the catalyst that subsequently contacts the material is less than the content of medium-strong acid. Simultaneously, the total acid content of the catalyst first increases and then decreases, and the catalyst contains... The percentage of acid molar content first increases and then decreases.

[0044] In the hydroisomerization dewaxing reactor of the present invention, preferably, the active metal content in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

[0045] In the graded-packed hydroisomerization dewaxing reactor of the present invention, preferably, based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is 2% to 20%; then the volume percentage content of the catalyst is 80% to 98%. More preferably, the volume percentage content of the protective agent is 2% to 10%; then the volume percentage content of the catalyst is 90% to 98%.

[0046] In the graded-filled hydroisomerization dewaxing reactor of the present invention, preferably, the protective agent has a pore volume of 0.4–0.8 mL / g and a specific surface area of ​​50–200 m². 2 / g.

[0047] In the hydroisomerization dewaxing reactor of the present invention, preferably, the active metal content in the protective agent is 0-5% by mass, and the remainder is Al2O3 and / or Al2O3-SiO2.

[0048] In the graded-filled hydroisomerization dewaxing reactor of the present invention, preferably, the active metal in the protective agent is selected from at least one of Co, Mo, Ni, and W.

[0049] In the graded-filled hydroisomerization dewaxing reactor of the present invention, preferably, along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer that are sequentially adjacent;

[0050] Regarding the active metal content of the protective agent, the first protective agent sublayer is less than or equal to the second protective agent sublayer.

[0051] In the hydroisomerization dewaxing reactor of the present invention, preferably, the active metal content of the protective agent in the first protective agent sublayer is 0-3 wt%, and the active metal content of the protective agent in the second protective agent sublayer is 1 wt%-5 wt%.

[0052] In the graded-packed hydroisomerization dewaxing reactor of the present invention, preferably, the pore volume of the protective agent in the first protective agent sublayer is 0.7-0.8 mL / g, and the specific surface area is 80-130 m². 2 / g; the pore volume of the protective agent in the second protective agent sublayer is 0.5-0.6 mL / g, and the specific surface area is 140-170 m² / g. 2 / g.

[0053] This invention discloses a method for producing lubricating oil base oil from waste plastics. First, the waste plastics are mixed with an organic solvent, effectively lowering the melting temperature and accelerating the melting process. This also dilutes the viscosity of the molten waste plastics. After filtering the molten system, inorganic additives and impurities are effectively removed, preventing them from clogging subsequent processing equipment and reducing maintenance cycles and costs. The fusible waste plastic raw material is then mixed with hydrotreated wax oil, simplifying the process for producing lubricating oil base oil from waste plastics. This allows for high-yield production of low-pour-point lubricating oil base oil through hydroisomerization. Furthermore, this invention employs a hydroisomerization dewaxing reactor with a specific gradation, ensuring a rational distribution of acid content and distribution in the catalyst. This improves the overall catalytic efficiency of the protective agent and catalyst, further reducing the low-temperature performance of the resulting base oil and increasing its yield. Additionally, this method can also improve the viscosity index of the base oil. This invention maximizes the economic benefits of recycling waste plastics and promotes the development of green and high-value-added recycling applications of waste plastics. Attached Figure Description

[0054] Figure 1 This is a graph showing the trend of the total acid content of the catalyst in the catalyst layer along the material flow direction in some embodiments of the present invention.

[0055] Figure 2 This is a graph showing the trend of the total acid content of the catalyst in the catalyst layer along the material flow direction in some other embodiments of the present invention. Detailed Implementation

[0056] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0057] This invention mainly utilizes waste plastics to produce lubricating oil base oil. The inorganic additives and impurities in the waste plastics are removed through pretreatment. At the same time, a hydroisomerization dewaxing reactor with specific gradation is used to maximize the production of high-value-added low-pour-point lubricating oil base oil from waste plastics.

[0058] Specifically, it includes two processes: waste plastic pretreatment and lubricating oil base oil production.

[0059] Waste plastic pretreatment:

[0060] Waste plastics are mixed with organic solvents and heated until all fusible portions of the waste plastics are melted to form a molten system. The molten system is then filtered to remove infusible impurities, and the organic solvents are recycled. The remaining portion is the fusible waste plastic raw material.

[0061] Production of lubricating oil base oil:

[0062] The fusible waste plastic raw material is mixed with hydrotreated wax oil, and then fed into a graded hydroisomerization dewaxing reactor in a hydrogen-containing environment. The mixture flows sequentially through a protective agent layer and a catalyst layer to carry out a hydroisomerization reaction, yielding a catalytic product. The catalytic product is then fractionated to obtain a lubricating oil base oil.

[0063] The protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst; along the material flow direction, the total acid content of the catalyst first increases and then decreases, and the catalyst contains... The molar percentage of acid in the total acid content first increases and then decreases.

[0064] Regarding the pretreatment process of waste plastics: Waste plastics and organic solvents are heated together to melt them. The melted system is then filtered to remove infusible solid impurities such as inorganic additives and inorganic impurities. The organic solvent is then recovered by flash evaporation for recycling. The remaining part yields fusible waste plastic raw materials.

[0065] The present invention does not limit the type of waste plastic, for example, it can be hydrocarbon plastic, specifically including at least one of polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-butene copolymer, and ethylene-octene copolymer.

[0066] The organic solvent is preferably selected from at least one of pentane, cyclopentane, hexane, cyclohexane, octane, isooctane, heptane, benzene, toluene, xylene, and naphtha. Preferably, the mass ratio of the fusible waste plastic raw material to the hydrogenated wax oil is 2:(1-10).

[0067] According to the method of the present invention, preferably, waste plastic is crushed into particles (e.g., with a particle size of 2-5 mm), mixed with an organic solvent, and then heated to 100-200°C for melting, more preferably 140-200°C, to form the molten system. Preferably, the mass ratio of the waste plastic to the organic solvent is 1:5 to 5:1.

[0068] Generally, the melting process takes 30–120 minutes. The specific time can be determined based on the melting status of the system. For example, during the melting process, when all the fusible waste plastics in the system have melted and the mass of the solid matter no longer decreases, the melting process can be stopped, and a molten system is obtained. This invention does not limit the specific reactor used for the melting process, as long as it can achieve stable melting.

[0069] After the melting process is completed, filtration is carried out, followed by flash evaporation to recover the organic solvents from the molten system. By recovering and reusing the organic solvents, the raw material cost of waste plastic recycling can be further reduced, and the organic solvents can be reused.

[0070] In one specific embodiment, thermogravimetric analysis shows that the initial and final decomposition temperatures of the waste plastics fall within the range of 100–500°C. Furthermore, to avoid corrosion of the reactor undergoing melting, the recycling of chlorine-containing waste plastics, such as PVC, is minimized.

[0071] In the process of recycling waste plastics, this invention first heats the waste plastics and organic solvent together for melting treatment, which effectively reduces the melting temperature of the waste plastics, accelerates the melting process, and dilutes the viscosity of the melted waste plastics, thus facilitating the filtration and impurity removal process. The resulting molten system is then filtered to remove inorganic additives and other infusible solid impurities from the waste plastics, making the subsequent hydroisomerization process more efficient.

[0072] Specifically, the removal of inorganic additives and other infusible solid impurities ensures the efficient operation of equipment in subsequent processing, preventing equipment blockage and downtime. This guarantees the smooth progress of the recycling process, eliminating the risk of increased costs due to restarting. Furthermore, it reduces equipment maintenance costs and extends maintenance cycles. Therefore, the pretreatment process of this invention helps reduce operating costs and improve the economic efficiency of enterprises. Importantly, the removal of inorganic additives and other infusible solid impurities also extends the catalytic activity and service life of the catalyst during hydroisomerization, preventing a decline in catalytic performance caused by catalyst pore blockage or active metal poisoning.

[0073] Regarding the production process of lubricating oil base oil: Meltable waste plastic raw materials are uniformly mixed with hydrotreated wax oil. The resulting mixture is then subjected to hydroisomerization to obtain high-quality lubricating oil base oil. Specifically, hydroisomerization is carried out in a graded-filled hydroisomerization dewaxing reactor. The mixed raw materials enter the reactor in a hydrogen-rich environment, sequentially passing through a protective agent layer and a catalyst layer to undergo the hydroisomerization reaction, yielding catalytic products. After the above hydroisomerization treatment, the catalytic products include a large amount of lubricating oil base oil and small amounts of gasoline, diesel, and C4 and below gas products. Therefore, the lubricating oil base oil can be further fractionated to obtain lubricating oil base oil, gasoline, diesel, and C4 and below products separately.

[0074] The production of lubricating base oil by mixing fusible waste plastic raw materials with hydrotreated wax oil reduces the problems of high pour point and cloud point of base oil caused by the increased harshness of the process of processing fusible waste plastic raw materials alone. The mixed processing conditions of fusible waste plastic raw materials and hydrotreated wax oil are milder. At the same time, it also reduces the yield of C4 and lower gas products in the hydrotreating system and increases the yield of base oil, thereby improving the overall economic benefits of the unit in processing waste plastics, realizing the high added value utilization of waste plastics, and enhancing the economic value of waste plastic recycling.

[0075] In the specific implementation of this invention, the mass content of hydrotreated wax oil in the mixed system is generally controlled to be above 10%. Reasonably controlling the amount of hydrotreated wax oil added to the mixed system helps to further reduce the processing difficulty of waste plastics, enabling waste plastics to be converted into lubricating base oil more efficiently. Therefore, the mass content of hydrotreated wax oil in the mixed system can be controlled at 30% or above, ensuring that the mass ratio of fusible waste plastic raw material to hydrotreated wax oil is no higher than 2:1. The inventors have found that as the amount of hydrotreated wax oil increases within a certain range, the yield of base oil obtained from waste plastic recycling initially shows an increasing trend and a decreasing pour point of the base oil, then remains basically unchanged. Therefore, for economic reasons, the mass ratio of fusible waste plastic raw material to hydrotreated wax oil is generally 2:(1-10).

[0076] Of course, the use of different waste plastics, organic solvents, and hydrotreated wax oils during the recycling of waste plastics will affect the yield of base oils. Therefore, generally speaking, when the mass ratio of fusible waste plastic raw material to hydrotreated wax oil is 2:(1-10), the yield of base oils can be maintained at a good level.

[0077] Further, the distillation range of the hydrotreated wax oil of the present invention is 280–600°C, more preferably 300–560°C. Exemplarily, the hydrotreated wax oil is selected from at least one of hydrotreated negative pressure line 1 wax oil, hydrotreated negative pressure line 2 wax oil, hydrotreated negative pressure line 3 wax oil, hydrotreated negative pressure line 4 wax oil, and hydrocracking tail oil. When the hydrotreated wax oil is a mixture of multiple types, the present invention does not limit the mass ratio of each type of hydrotreated wax oil. To ensure a high yield of base oil, the sulfur content of the hydrotreated wax oil is ≤30 μg / g, the nitrogen content is ≤15 μg / g, and the final boiling point is not higher than 600°C.

[0078] In the hydroisomerization process, preferably, the hydrogen-to-oil volume ratio is 200–800:1, the reaction temperature is 300–400°C, the reaction pressure is 6–15 MPa, and the volume hourly space velocity is 0.5–2.0 h⁻¹. -1 More preferably, the hydrogen-to-oil volume ratio is 200–800:1, the reaction temperature is 320–380°C, the reaction pressure is 8–12 MPa, and the volume hourly space velocity is 0.8–1.5 h⁻¹. -1 .

[0079] This invention employs a graded-filled hydroisomerization dewaxing reactor for hydroisomerization treatment. Specifically, along the material flow direction: a protective agent layer and a catalyst layer are sequentially arranged in the hydroisomerization dewaxing reactor; the protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst; the total acid content of the catalyst first increases and then decreases, and the catalyst contains... The molar percentage of acid in the total acid content first increases and then decreases.

[0080] Figure 1 This is a graph showing the trend of the total acid content of the catalyst in the catalyst layer along the material flow direction in some embodiments of the present invention. The total acid content of the catalyst can change in a gradient along the material flow direction, first increasing and then decreasing. Figure 2 This is a graph showing the trend of the total acid content of the catalyst in the catalyst layer along the material flow direction in some other embodiments of the present invention. Along the material flow direction, the total acid content of the catalyst can gradually increase and then gradually decrease.

[0081] This invention achieves this by adjusting the number and strength of acid centers in the catalyst (especially...). Acids can effectively regulate the distribution of products and the yield of base oils.

[0082] Specifically, the catalyst comprises an active metal and a support. Based on the total mass of the catalyst, the active metal comprises 0.1% to 1.0% by mass, more preferably 0.2% to 0.5% by mass; the remainder is the support.

[0083] The active metal can be selected from at least one of Pt, Pd, Ru, and Ni, and more preferably Pt and / or Pd.

[0084] The support contains at least one molecular sieve with a ten-membered ring topology; the molecular sieve includes ZSM-5, SAPO-11, ZSM-22, ZSM-35, ZSM-23, ZSM-48, SAPO-41, etc.; more preferably, the support further contains at least one amorphous inorganic porous material, the amorphous inorganic porous material including alumina, silica, zirconium oxide, titanium oxide and their composite oxides (alumina-silica, zirconium oxide-silica, titanium oxide-silica, alumina-zirconium oxide, zirconium oxide-titanium oxide, alumina-titanium oxide). Based on the total mass of the catalyst, the mass percentage of the molecular sieve is preferably 40% to 80%, more preferably 55% to 75%; the mass percentage of the amorphous inorganic porous material is 19% to 59.9%, more preferably 25% to 50%.

[0085] The catalyst layer can contain catalysts prepared by one type of molecular sieve with different amounts of acid, such as catalysts prepared by ZSM-22 molecular sieve with different amounts of acid, or catalysts prepared by different types of molecular sieve with different amounts of acid.

[0086] Preferably, the total acid content of the catalyst is 50–300 μmol / g, more preferably 100–300 μmol / g; the content of weak acid is 10–150 μmol / g, more preferably 20–100 μmol / g; and the content of moderately strong acid is 5–250 μmol / g, more preferably 10–220 μmol / g. In the catalyst… The preferred molar percentage content of acid in the total acid content is 5% to 50%.

[0087] When the above catalysts are used in a graded packing in the catalyst bed, the total acid content of the catalyst first increases and then decreases along the material flow direction, and the catalyst contains... The percentage of acid molar content first increases and then decreases.

[0088] For example, in a preferred embodiment, along the material flow direction, the catalyst layer includes a first catalyst sublayer, a second catalyst sublayer, and a third catalyst sublayer that are sequentially adjacent to each other;

[0089] In the first catalyst sublayer, the content of weak acid is greater than the content of medium-strong acid; in the second catalyst sublayer, the content of weak acid is less than the content of medium-strong acid; in the third catalyst sublayer, the content of weak acid is less than the content of medium-strong acid.

[0090] Regarding the total acidity of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer; regarding the catalyst... The molar percentage content of acid in the total acid content, wherein the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer.

[0091] It is understood that in this invention, the content of weak acid in the catalyst that first contacts the material is greater than the content of medium-strong acid, while the content of weak acid in the catalyst that subsequently contacts the material is less than the content of medium-strong acid. Simultaneously, the total acid content of the catalyst first increases and then decreases, and the catalyst contains... The percentage of acid molar content first increases and then decreases.

[0092] Preferably, the total acid content of the first catalyst sublayer is 50–200 μmol / g, the content of weak acids is 20–100 μmol / g, and the content of moderately strong acids is 10–80 μmol / g. The molar content of the acid is 5% to 20%. More preferably, the total acid content is 50 to 150 μmol / g, the weak acid content is 30 to 100 μmol / g, and the moderately strong acid content is 10 to 60 μmol / g. The molar content of acid is 5% to 15%.

[0093] The total acid content of the second catalyst sublayer is 150–300 μmol / g, the content of weak acids is 30–100 μmol / g, and the content of moderately strong acids is 120–200 μmol / g. The molar content of the acid is 20%–50%; more preferably, the total acid content is 200–300 μmol / g, the weak acid content is 50–100 μmol / g, and the moderately strong acid content is 150–200 μmol / g. The molar content of acid is 30% to 50%.

[0094] The total acid content of the third catalyst sublayer is 100–300 μmol / g, the content of weak acids is 20–100 μmol / g, and the content of moderately strong acids is 50–200 μmol / g. The molar content of the acid is 20%–50%; more preferably, the total acid content is 100–250 μmol / g, the content of weak acid is 20–80 μmol / g, and the content of moderately strong acid is 80–200 μmol / g. The molar content of acid is 25% to 50%.

[0095] Using the graded packing method of the catalyst layer of the present invention, the material can be mixed with hydrogen and then enter the catalytic reaction unit for reaction. The reaction products generated by the catalytic reaction unit enter the fractionation equipment for base oil cutting to produce lubricating oil base oils of different viscosities.

[0096] It is understood that in this invention, the total acid content of the catalyst in the first catalyst sublayer can be the same as or different from the total acid content of the catalyst in the third catalyst sublayer, as long as the total acid content of the catalyst first increases and then decreases along the material flow direction. In the first catalyst sublayer... The molar percentage of acid and the third catalyst sublayer The molar percentage of acid can be the same or different, as long as it allows for the concentration of acid in the catalyst to increase along the material flow direction. The molar percentage of acid can be increased first and then decreased.

[0097] The present invention produces base oil using the above-mentioned reactor, which can further improve the catalytic effect of the catalyst, increase the yield of base oil, and improve the viscosity index, pour point, and cloud point of the base oil.

[0098] In this invention, the amount of acid in the catalyst layer can be further limited in order to further improve the catalytic efficiency of the catalyst and improve the yield, viscosity index, pour point and cloud point of the base oil.

[0099] In some embodiments of the present invention, in at least one catalyst sublayer of the catalyst layer... The molar content of acid is 5% to 50%. Furthermore, in at least one catalyst sublayer, The molar content of acid ranges from 5% to 40%.

[0100] The catalyst of the present invention contains weak acid centers and medium-strong acid centers. In the catalyst layer, in at least one catalyst sublayer, the total acid content of the catalyst is 50 to 300 μmol / g. Further, in at least one catalyst sublayer, the total acid content of the catalyst is 100 to 300 μmol / g.

[0101] In some embodiments of the present invention, in the catalyst layer, in at least one catalyst sublayer, the content of the weak acid of the catalyst is 10 to 150 μmol / g; and / or in at least one catalyst sublayer, the content of the medium-strong acid of the catalyst is 5 to 250 μmol / g.

[0102] Furthermore, in the catalyst layer, at least one catalyst sublayer has a weak acid content of 20–100 μmol / g; and / or at least one catalyst sublayer has a medium-strong acid content of 10–200 μmol / g.

[0103] In some embodiments of the present invention, in the protective agent layer of the hydroisomerization dewaxing reactor, the content of active metal in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

[0104] In the hydroisomerization dewaxing reactor of this invention, a protective agent layer is provided before the catalyst layer. It is understood that the material first flows through the protective agent layer for impurity removal, and then the impurity-removed material flows through the catalyst layer for catalytic reaction. By first removing impurities from the material and then carrying out the catalytic reaction, this invention can convert the material into base oil to a greater extent, increase the yield of base oil, and also reduce the impurity content in the base oil, thereby improving the quality of the base oil.

[0105] Based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is preferably 2% to 20%; then the volume percentage content of the catalyst is 80% to 98%. More preferably, the volume percentage content of the protective agent is 2% to 10%; then the volume percentage content of the catalyst is 90% to 98%.

[0106] The active metal in the protective agent can remove organic impurities (desulfurization and denitrification). The higher the content of the active metal in the protective agent, the stronger its impurity removal ability (the stronger its desulfurization and denitrification ability). In this invention, the active metal can be at least one of Co, Mo, Ni, and W. The active metal in the protective agent has a mass percentage content of 0-5%, with the remainder being Al2O3 and / or Al2O3-SiO2.

[0107] The pore volume of the protective agent is preferably 0.4–0.8 mL / g, and the specific surface area is preferably 50–200 m² / g. 2 / g.

[0108] In this invention, two or more protective agents can be provided in the protective agent layer, and along the material flow direction, the pore volume between the protective agents gradually decreases or decreases in stages, while the specific surface area of ​​the protective agents gradually increases or increases in stages.

[0109] The pore volume between protective agents can adsorb inorganic impurities; the larger the pore volume, the stronger the adsorption capacity.

[0110] This invention grades the protective agent according to its impurity removal ability, which can improve the impurity removal effect of the protective agent, thereby improving the catalytic effect of the catalytic reaction and increasing the yield and quality of the base oil.

[0111] For example, along the material flow direction, the protective agent layer includes a first protective agent sublayer and a second protective agent sublayer that are sequentially adjacent to each other;

[0112] Regarding the active metal content of the protective agent, the first protective agent sublayer is less than or equal to the second protective agent sublayer.

[0113] For example, the active metal content of the protectant in the first protective agent sublayer is 0-3 wt%, and the active metal content of the protectant in the second protective agent sublayer is 1 wt%-5 wt%. The active metal in the protectant is selected from one or more combinations of Co, Mo, Ni, and W. Except for the active metal, the rest of the protectant is an amorphous inorganic porous material, preferably alumina (Al2O3) and / or amorphous aluminum silicate (Al2O3-SiO2).

[0114] Preferably, the pore volume and specific surface area of ​​the first protective agent sublayer are 0.7–0.8 mL / g and 80–130 m², respectively. 2 / g; the pore volume and specific surface area of ​​the second protective agent sublayer are 0.5–0.6 mL / g and 140–170 m², respectively. 2 / g.

[0115] The technical solution of the present invention will be further described below with reference to specific embodiments. All numerical specifications (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that can be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are understood to be preceded by the term "about".

[0116] Examples 1-3, Comparative Examples 1-3

[0117] Examples 1-3 and Comparative Examples 1-3 each provide a hydroisomerization dewaxing reactor, wherein the gradation of the catalyst layer and the protective agent layer is shown in Table 1.

[0118] Table 1 Properties of Protective Agents and Catalysts, and Packing Methods

[0119]

[0120]

[0121]

[0122] Example 4

[0123] This embodiment mixes waste plastics with hydrogenated non-reduced 4-line wax oil to obtain mixed oil 1A, including the following steps:

[0124] 1) Take 10 kg of polyethylene-propylene waste plastic granules (particle size 2-5 mm) obtained by granulation (initial decomposition temperature 209℃, 50% decomposition temperature 337℃, decomposition termination temperature 416℃, melting range of waste plastic 95-128℃) obtained by granulation (by thermogravimetric analysis). Add them to a batch reactor with flash evaporation and stirring functions. Then add 2 kg of heptane to the batch reactor, seal the batch reactor, turn on the stirring function, heat to 180℃, and keep the temperature constant for 90 min to obtain the molten system.

[0125] The molten system was then filtered and weighed, yielding 0.16 kg of infusible solid. The remaining organic solvent was then recovered via flash evaporation for reuse in dissolving plastics, with the final residue being molten waste plastic raw material.

[0126] 2) The above-mentioned fusible waste plastic raw materials are mixed with the hydrogenated non-reduced wax oil in Table 2 at a mass ratio of 2:1 to obtain mixed oil 1A. The relevant parameters of mixed oil 1A are shown in Table 3.

[0127] Table 2 Properties of Hydrotreated No. 4 Wax Oil

[0128]

[0129] Table 3 Properties of Blended Oil 1A

[0130]

[0131] Comparative Example 4

[0132] This comparative example mixes waste plastic with unhydrogenated N4 wax oil to obtain mixed oil 1B. The difference from Example 4 is that the molten waste plastic in Example 4 is mixed with the unhydrogenated N4 wax oil in Table 4 at a mass ratio of 2:1 to obtain mixed oil 1B in Table 5.

[0133] Table 4 shows the untreated negative 4 wax oil, which, after hydrogenation treatment, becomes the hydrogenated negative 4 wax oil shown in Table 2.

[0134] Table 4 Properties of Unhydrotreated Pale Fourier Line Wax Oil

[0135]

[0136] As can be seen from Tables 2 and 4, compared with the hydrotreated N4 wax oil, the untreated N4 wax oil has a slightly higher density, higher initial boiling point and final boiling point, and more importantly, higher sulfur content, nitrogen content, and iron and calcium metal impurities. Sulfur and nitrogen are both poisons for isomerization dewaxing catalysts. High content will cause poisoning of precious metals in the catalyst and deactivation. High content of metal impurities will cause blockage of the catalyst pore structure and deactivation of the catalyst.

[0137] Table 5 Properties of Blended Oil 1B

[0138]

[0139] The mixed oil 1B has higher sulfur, nitrogen, and iron and calcium metal impurities, which makes the isomerization dewaxing catalyst more prone to deactivation.

[0140] Example 5

[0141] This embodiment mixes waste plastics with hydrogenated reduced-strength wax oil to obtain mixed oil 2A, including the following steps:

[0142] 1) Take 5 kg of polyethylene waste plastic and polybutene waste plastic obtained by granulation (particle size 2-5 mm) and mix them to form a mixed plastic. The mass ratio of polyethylene waste plastic to polybutene waste plastic in the mixed plastic is 1:1. (Thermogravimetric analysis of the mixed particles showed that the initial decomposition temperature was 219℃, the 50% decomposition temperature was 348℃, the decomposition termination temperature was 435℃, and the melting range of the waste plastic was 101-142℃). Add the mixed particles to a batch reactor equipped with flash evaporation and stirring functions, then add 5 kg of cyclohexane to the batch reactor. Seal the batch reactor, turn on the stirring function, heat to 120℃, and hold at that temperature for 120 min to obtain a molten system.

[0143] Subsequently, the molten system was filtered and weighed to obtain 0.22 kg of infusible solid. The remaining organic solvent was then recovered by flash evaporation for use in the next dissolution of plastics. The remaining part was then a molten waste plastic raw material.

[0144] 2) The above-mentioned fusible waste plastic raw materials are mixed with the hydrogenated first-line wax oil in Table 6 at a mass ratio of 2:5 to obtain mixed oil 2A. The relevant parameters of mixed oil 2A are shown in Table 7.

[0145] Table 6 Properties of Hydrogenated Linear Wax Oil

[0146]

[0147] Table 7 Properties of Blended Oil 2A

[0148]

[0149] Comparative Example 5

[0150] This comparative example mixes waste plastics with unhydrogenated first-line wax oil to obtain mixed oil 2B. The difference from Example 5 is that the molten waste plastics in Example 5 are mixed with the unhydrogenated first-line wax oil in Table 8 at a mass ratio of 2:5 to obtain mixed oil 2B in Table 9.

[0151] Table 8 shows the untreated first-line wax oil, which, after hydrogenation treatment, yields the hydrogenated first-line wax oil shown in Table 6.

[0152] Table 8 Properties of Unhydrotreated Line 1 Wax Oils

[0153]

[0154] Table 9 Properties of Blended Oils 2B

[0155]

[0156] As can be seen from Tables 6 and 8, compared with the hydrotreated first-line dewaxing oil, the untreated first-line dewaxing oil has a slightly higher density, higher initial boiling point and final boiling point, and, more importantly, higher sulfur content, nitrogen content, and iron and calcium metal impurities. Sulfur and nitrogen are both poisons for isomerization dewaxing catalysts. High content will cause poisoning of precious metals in the catalyst, thus leading to catalyst deactivation. High content of metal impurities will cause blockage of the catalyst pore structure, resulting in catalyst deactivation.

[0157] Example 6

[0158] This embodiment mixes waste plastics with hydrocracking tail oil to obtain mixed oil 3, including the following steps:

[0159] 1) Take 4 kg of polyethylene waste plastic obtained by granulation (particle size 2-5 mm) and mix it with polyoctene waste plastic particles (the mass ratio of polyethylene waste plastic to polyoctene waste plastic is 1:4) to form a mixed plastic. (Thermogravimetric analysis of the mixed plastic showed that the initial decomposition temperature was 227℃, the 50% decomposition temperature was 352℃, the decomposition termination temperature was 448℃, and the melting range of the waste plastic was 101-142℃). Add the mixed plastic to a batch reactor equipped with flash evaporation and stirring functions, then add 20 kg of naphtha to the batch reactor, seal the batch reactor, turn on the stirring function, heat to 200℃, and hold at that temperature for 30 minutes to obtain a molten system.

[0160] Subsequently, the molten system was filtered and weighed to obtain 0.34 kg of infusible solid. The remaining organic solvent was then recovered by flash evaporation for use in the next dissolution of plastics. The remaining part was then a molten waste plastic raw material.

[0161] 2) The above-mentioned fusible waste plastic raw materials are mixed with the hydrocracking tail oil in Table 10 at a mass ratio of 2:10 to obtain mixed oil 3. The relevant parameters of mixed oil 3 are shown in Table 11.

[0162] Table 10 Properties of Hydrocracking Tail Oil

[0163]

[0164] Table 11 Properties of Blended Oils

[0165]

[0166] Comparative Example 6

[0167] This comparative example uses the mixed plastic particles from Example 6 for pretreatment without adding organic solvents, and mixes them with hydrocracking tail oil to obtain mixed oil 4.

[0168] The difference between this comparative example and Example 6 is that the mixed plastic particles from Example 6 were added to a batch reactor without any organic solvent. After sealing, the stirring function was turned on, and the temperature was heated to 200°C. After holding the temperature for 30 minutes, the molten mixed waste plastic and hydrocracking tail oil were uniformly mixed at a mass ratio of 2:10 to obtain mixed oil 4. The relevant parameters of mixed oil 4 are shown in Table 12.

[0169] Table 12 Properties of Blended Oils

[0170]

[0171] Experimental Example 1

[0172] The six mixed oils (mixed oil 1A, mixed oil 1B, mixed oil 2A, mixed oil 2B, mixed oil 3A, and mixed oil 3B) from Examples 4-6 and Comparative Examples 4-6 were subjected to hydroisomerization reactions in hydroisomerization dewaxing reactors with the six different gradations listed in Table 1. The reaction process conditions for the hydroisomerization treatment are shown in Table 13.

[0173] After hydroisomerization, the reaction system is fractionated to obtain C4 and below gas, gasoline, diesel and lubricating oil base products, the properties of which are shown in Table 14.

[0174] Table 13 Hydroisomerization Process Conditions

[0175] Hydroisomerization treatment Reaction temperature, °C 380 Reaction pressure, MPa 10 Liquid hourly space velocity, h -1 ]] 1.5 Hydrogen to oil volume ratio 800

[0176] Table 14 Properties of products obtained from hydroisomerization dewaxing reactors with different blending oils and different packing methods

[0177]

[0178]

[0179] Compared to directly mixing untreated vacuum wax oil with molten plastic (mixture oil 1B and mixture oil 2B), mixing hydrotreated wax oil (mixture oil 1A and mixture oil 2A) with molten plastic and then performing a hydroisomerization reaction using an isomerization dewaxing catalyst results in base oils with lower sulfur content, nitrogen content, pour point, cloud point, and yield of gases below C4, as well as higher base oil yield. Mixing untreated wax oil with molten plastic results in excessively high sulfur and nitrogen content in the raw materials, which poisons the isomerization dewaxing catalyst, causing rapid catalyst deactivation. Simultaneously, the sulfur and nitrogen content of the produced base oils is excessively high, far exceeding the requirements for Group II and Group III base oils.

[0180] Using the graded packing hydroisomerization dewaxing reactor defined in Examples 1-3, the mixed oil formed by hydrotreated wax oil and molten plastic or hydrocracking tail oil and molten plastic is processed. The resulting base oil has lower sulfur content, nitrogen content, pour point, cloud point and C4 and lower gas yield, and higher base oil yield. It has high technical advantages and good application prospects.

[0181] Experimental Example 2

[0182] The two mixed oils (mixed oil 1A and mixed oil 1B) from Example 4 and Comparative Example 4 were subjected to hydroisomerization reactions in the hydroisomerization dewaxing reactor of Example 3 as shown in Table 1. The reaction process conditions for hydroisomerization are shown in Table 15.

[0183] After hydroisomerization, the reaction system is fractionated to obtain C4 and below gas, gasoline, diesel and lubricating oil base products, the properties of which are shown in Table 16.

[0184] Table 15 Hydroisomerization Process Conditions

[0185] Hydroisomerization treatment Reaction temperature, °C 370 Reaction pressure, MPa 15 Liquid hourly space velocity, h -1 ]]> 0.5 Hydrogen to oil volume ratio 500

[0186] Table 16 Properties of products obtained from hydroisomerization dewaxing reactors using the graded packing method of Example 3 for different blended oils

[0187]

[0188] Experimental Example 3

[0189] The two mixed oils (mixed oil 3 and mixed oil 4) from Example 6 and Comparative Example 6 were subjected to hydroisomerization in a hydroisomerization dewaxing reactor according to the gradation and packing method in Example 3 as shown in Table 1. The reaction process conditions for hydroisomerization are shown in Table 17.

[0190] After hydroisomerization, the reaction system is fractionated to obtain C4 and below gas, gasoline, diesel and lubricating oil base products, the properties of which are shown in Table 18.

[0191] Table 17 Hydroisomerization Process Conditions

[0192] Hydroisomerization treatment Reaction temperature, °C 300 Reaction pressure, MPa 6 Liquid hourly space velocity, h -1 ]]> 2 Hydrogen to oil volume ratio Hydroisomerization treatment Reaction temperature, °C Reaction pressure, MPa Hydrogen to oil volume ratio Hydroisomerization treatment Reaction temperature, °C Reaction pressure, MPa Hydrogen to oil volume ratio Hydroisomerization treatment Reaction temperature, °C Reaction pressure, MPa Hydrogen to oil volume ratio Hydroisomer 200

[0193] Table 18 Properties of products obtained from hydroisomerization dewaxing reactors using the graded packing method of Example 3 for different blended oils

[0194]

[0195] Experiments 1, 2, and 3 modified the hydroisomerization process conditions, using a hydrogen-to-oil volume ratio of 200–800:1, a reaction temperature of 300–400°C, a reaction pressure (hydrogen partial pressure) of 6–15 MPa, and a volume hourly space velocity of 0.5–2.0 h⁻¹. -1 Compared to the direct mixing of unhydrotreated wax oil with molten plastic or molten plastic without solvent treatment with hydrocracking tail oil, the mixed oil formed by hydrotreated wax oil with molten plastic or hydrocracking tail oil with solvent-treated molten plastic produces base oil with lower sulfur content, nitrogen content, pour point, cloud point, and C4 and lower gas yield, and higher base oil yield. It has significant technical advantages and good application prospects.

[0196] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for producing lubricating oil base oil from waste plastics, wherein, The method includes the following steps: Waste plastic pretreatment: Waste plastics are mixed with organic solvents and heated until all fusible portions of the waste plastics are melted to form a molten system. The molten system is then filtered to remove infusible impurities, and the organic solvents are recycled. The remaining portion is the fusible waste plastic raw material. Production of lubricating oil base oil: The fusible waste plastic raw material is mixed with hydrotreated wax oil, and then fed into a graded hydroisomerization dewaxing reactor in a hydrogen-containing environment. The mixture flows sequentially through a protective agent layer and a catalyst layer to carry out a hydroisomerization reaction, yielding a catalytic product. The catalytic product is then fractionated to obtain a lubricating oil base oil. The protective agent layer is filled with a protective agent, and the catalyst layer is filled with a catalyst. Along the material flow direction, the total acid content of the catalyst first increases and then decreases, and the molar percentage of Brönsted acid in the catalyst to the total acid content first increases and then decreases. The catalyst layer comprises a first catalyst sublayer, a second catalyst sublayer, and a third catalyst sublayer that are sequentially adjacent to each other. In the first catalyst sublayer, the content of weak acid is greater than the content of moderately strong acid; in the second catalyst sublayer, the content of weak acid is less than the content of moderately strong acid; in the third catalyst sublayer, the content of weak acid is less than the content of moderately strong acid. The total acid content of the second catalyst sublayer is greater than the total acid content of the first catalyst sublayer and the third catalyst sublayer; The molar percentage content of Brönsted acid in the second catalyst sublayer is greater than that in the first and third catalyst sublayers.

2. The method according to claim 1, wherein, The organic solvent is selected from at least one of pentane, cyclopentane, hexane, cyclohexane, isooctane, heptane, benzene, toluene, xylene, and naphtha.

3. The method according to claim 1, wherein, Waste plastic is crushed into granules, mixed with an organic solvent, and then heated to 100-200°C to melt, forming the molten system.

4. The method according to claim 1, wherein, The hydrogenated wax oil has a sulfur content ≤30 μg / g, a nitrogen content ≤15 μg / g, and a distillation range of 280~600℃.

5. The method according to claim 1, wherein, The mass ratio of the fusible waste plastic raw material to the hydrogenated wax oil is 2:(1~10).

6. The method according to claim 1, wherein, The total acid content of the first catalyst sublayer is 50~200 μmol / g, the content of weak acids is 20~100 μmol / g, the content of medium-strong acids is 10~80 μmol / g, and the molar content of Brönsted acids is 5%~20%. The total acid content of the second catalyst sublayer is 150~300 μmol / g, the weak acid content is 30~100 μmol / g, the medium-strong acid content is 120~200 μmol / g, and the molar content of Brönsted acid is 20%~50%. The total acid content of the third catalyst sublayer is 100~300 μmol / g, the content of weak acid is 20~100 μmol / g, the content of medium-strong acid is 50~200 μmol / g, and the molar content of Brönsted acid is 20%~50%.

7. The method according to claim 1, wherein, The content of active metal in the protective agent gradually increases or remains unchanged, and / or the pore volume of the protective agent decreases and the specific surface area increases.

8. The method according to claim 7, wherein, Based on the total volume of the protective agent and the catalyst, the volume percentage content of the protective agent is 2% to 20%.

9. The method according to claim 7, wherein, Along the material flow direction, the protective agent layer includes a first protective agent sublayer and a second protective agent sublayer that are sequentially adjacent to each other; The content of active metal in the first protective agent sublayer is less than or equal to the content of active metal in the second protective agent sublayer; The active metal content of the protectant in the first protective agent sublayer is 0~3wt%, and the active metal content of the protectant in the second protective agent sublayer is 1wt%~5wt%. The pore volume of the protective agent in the first protective agent sublayer is 0.7~0.8 mL / g, and the specific surface area is 80~130 m². 2 / g; The second protective agent sublayer has a pore volume of 0.5~0.6 mL / g and a specific surface area of ​​140~170 m². 2 / g.

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