Method for producing lubricant base oil by using waste plastics

Abstract

The invention discloses a method for producing lubricant base oil by using waste plastics. The method comprises the following steps: mixing waste plastics and an organic solvent, heating to form a melting system, filtering to remove non-meltable impurities, and then recycling the organic solvent to obtain a meltable waste plastic raw material; mixing the meltable waste plastic raw material with hydrotreated wax oil, then feeding the mixture into a graded filling hydroisomerization dewaxing reactor in a hydrogen environment, sequentially flowing through a protective agent layer and a catalyst layer to perform hydroisomerization reaction to obtain a catalytic product, and fractionating to obtain the lubricant base oil. According to the method, inorganic additives and inorganic impurities in the waste plastics are removed through pretreatment of the waste plastics, meanwhile, grading filling of the protective agent and the catalyst is carried out in the hydroisodewaxing reactor, and the waste plastics are utilized to the maximum extent to produce the low-pour-point lubricant base oil with the high additional value.

Description

Technical Field

[0001] The invention relates to the field of petrochemical industry, and in particular to a method for producing lubricating oil base oil by utilizing waste plastics. Background Art

[0002] While plastic products bring convenience to people's lives, they also cause increasingly serious pollution. Discarded plastics, after long-term exposure to the sun and weathering, emit some harmful substances that cause serious damage to the ecological environment. It is also a serious waste of petrochemical resources.

[0003] The existing waste plastic treatment technologies mainly include landfill, incineration, physical recycling and chemical recycling. Among them, due to the slow decomposition rate and low stacking density of waste plastics, 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 method at present.

[0004] CN106520168A discloses a method for treating waste plastics, in which inferior oil and waste plastics are mixed to undergo a thermal cracking reaction, and the resulting cracking gas is contacted with a catalyst to undergo a catalytic reaction to form gas phase products and liquid phase oil products, and the liquid phase oil products are hydrogenated to form naphtha and diesel. The gas product in the product generated by this process is relatively large, and additional processes are required to process the gas product, resulting in a high processing cost.

[0005] CN101896582A discloses a method for recycling waste plastics, which comprises the steps of pyrolyzing a biomass, waste plastics and Fischer-Tropsch wax to obtain pyrolysis oil for fractionation, hydrogenating at least one fraction, and catalytically isomerizing at least one intermediate after hydrogenation to obtain an isomerized product. Since the waste plastics are not pre-treated, a large amount of solid residue will be generated in the pyrolysis device, which may easily cause the device to be blocked. At the same time, a large amount of gas will be generated, making it difficult to recycle the gas.

[0006] CN107987864A discloses a method and a production device for preparing biomass oil and fuel gas from biomass and waste plastics. Biomass (wood fiber) and waste plastics are thermally cracked in a vacuum pyrolyzer 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 a liquid phase hydrogenation process, wherein the waste plastics are subjected to hydrogenation cracking through a liquid phase hydrogenation reactor, and the obtained cracking products are subjected to liquid phase hydrogenation isomerization reaction with at least one of paraffin-based distillate oil and Fischer-Tropsch wax to obtain lubricating oil base oil, diesel and hydrocarbon gas. The waste plastics contain a certain amount of inorganic additives, and there is a lack of pre-treatment of the waste plastics. Summary of the invention

[0008] The object of the present invention is to provide a method for producing lubricating oil base oil by utilizing waste plastics, wherein inorganic additives and inorganic impurities in the waste plastics are removed by pre-treatment of the waste plastics, and protective agent and catalyst grading are loaded in a hydroisomerization dewaxing reactor, so as to produce high-value-added low pour point lubricating oil base oil by utilizing waste plastics to the maximum extent.

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

[0010] A method for producing lubricating oil base oil using waste plastics comprises the following steps:

[0011] Pretreatment of waste plastics:

[0012] The waste plastics are mixed with an organic solvent and heated until the fusible part of the waste plastics is completely melted to form a molten system; the molten system is filtered to remove infusible impurities, and then the organic solvent is recycled, and the remaining part is the fusible waste plastic raw material;

[0013] Production of lubricant base oils:

[0014] The fusible waste plastic raw material is mixed with the wax oil after hydrogenation treatment, and then enters a graded and loaded hydroisomerization dewaxing reactor under a hydrogen environment, flows through a protective agent layer and a catalyst layer in sequence to perform a hydroisomerization reaction to obtain a catalytic product; the catalytic product is fractionated to obtain a lubricating oil base oil;

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

[0016] In the method for producing lubricating oil base oil from waste plastics of the present invention, the waste plastics are pre-treated by mixing and melting with an organic solvent, and then filtering to remove inorganic additives and inorganic impurities therein; after filtering, the organic solvent in the molten system is flash-evaporated and recovered so that the organic solvent can be repeatedly recycled, and the fusible waste plastic raw material is obtained after filtering and removing impurities and recovering the solvent in the molten system.

[0017] At the same time, the production method of the present invention also uses a hydroisomerization dewaxing reactor with a specific graded filling, and adjusts the number and strength of the acid centers of the catalyst (especially Acid), can effectively adjust the distribution of catalytic product oil and the yield of base oil.

[0018] By loading the protective agent layer and the catalyst layer in the hydroisomerization dewaxing reactor in a graded combination, the acid content and acid distribution in the catalyst are reasonably distributed, so that the overall catalytic efficiency of the protective agent and the catalyst is improved, and the low-temperature performance of the produced base oil is further reduced. Since the acid content and distribution in the catalyst layer are reasonably limited, the cracking performance of the oil product is reduced, and the oil product is subjected to the hydroisomerization reaction to the maximum extent, thereby improving the yield of the base oil. At the same time, the method of the present 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, the waste plastics are crushed into particles and mixed with an organic solvent, and then heated to 100-200° C. for melting to form the molten system.

[0022] The present invention uses hydrogenated wax oil and fusible waste plastic raw materials to mix and carry out hydrogenation isomerization reaction. The content of sulfur, nitrogen and metal impurities in the hydrogenated wax oil is lower, which is conducive to the isomerization dewaxing catalyst to maintain high activity for a long time and is not easy to cause catalyst deactivation. Preferably, the sulfur content of the hydrogenated wax oil is ≤30μg / g, the nitrogen content is ≤15μg / g, and the distillation range is 280-600°C, more preferably 300-560°C.

[0023] According to the method of the present invention, preferably, the mass ratio of the meltable 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: hydrotreated first-line wax oil, hydrotreated second-line wax oil, hydrotreated third-line wax oil, hydrotreated fourth-line 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 6-15MPa, and the volume space velocity is 0.5-2.0h -1More preferably, the volume ratio of hydrogen to oil is 200 to 800:1, the reaction temperature is 320 to 380°C, the reaction pressure is 8 to 12 MPa, and the volume space velocity is 0.8 to 1.5 h -1 .

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

[0027] In the graded 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 hydroisomerization dewaxing reactor of the present invention, preferably, the carrier contains at least one molecular sieve with a ten-membered ring topology structure; 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, zirconia, titania and their composite oxides, and their composite oxides include alumina-silica, zirconia-silica, titania-silica, alumina-zirconia, zirconia-titania, alumina-titania, etc.

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

[0031] In this field, the types of acids in catalysts are divided into: Acid and Lewis acid. Among them, Acid, also known as proton acid, is a type of acid defined using the Bronsted acid-base proton theory. The Bronsted acid-base theory calls substances that can donate protons acids. The stronger the ability to donate protons, the stronger the acidity. Lewis acid is a type of acid defined using the Lewis acid-base theory. The Lewis acid-base theory calls substances with empty orbitals that can accept electron pairs acids. The stronger the ability to accept electron pairs, the stronger the acidity.

[0032] The present invention can use pyridine infrared spectroscopy analysis (Py-IR) characterization method to determine the catalyst The molar content of acid and Lewis acid, among which pyridine is adsorbed on The acid center forms a pyridinium ion with an infrared characteristic absorption peak at 1530-1560cm -1 The corresponding molar amount is The molar amount of acid; pyridine is adsorbed on the Lewis acid center, and the infrared characteristic absorption peak is at 1440~1460cm -1 , the corresponding molar amount is the molar amount of Lewis acid. The molar content of acid refers to the ratio based on The total molar amount of acid and Lewis acid, The mole percentage of acid.

[0033] In the present invention, the acid in the catalyst is divided into weak acid, medium-strong acid and strong acid according to the acid strength. Among them, the content of weak acid refers to the molar content of weak acid, the content of medium-strong acid refers to the molar content of medium-strong acid, the content of strong acid refers to the molar content of strong acid, and the total acid content refers to the sum of the molar contents of weak acid, medium-strong acid and strong acid. In some embodiments, ammonia programmed temperature desorption (NH 3 -TPD) method was used to determine the molar content of acids of various strengths and the total acid content in the catalyst. 3 -On the TPD desorption chart, the amount of ammonia desorbed between 100°C and 230°C corresponds to the amount of weak acid, the amount of ammonia desorbed between 230°C and 370°C corresponds to the amount of medium-strong acid, and the amount of ammonia desorbed above 370°C corresponds to the amount of strong acid. The specific operation method may include: purging the catalyst sample with helium at 500°C for 1 hour, cooling it to 60°C, introducing saturated ammonia vapor, and pulse adsorption five times to reach equilibrium; heating it to 100°C and purging it for 2 hours, then program heating at a heating rate of 10°C / min to desorb ammonia, and heating it to 650°C; absorbing the desorbed ammonia with hydrochloric acid solution, and then titrating the excess hydrochloric acid with sodium hydroxide solution, and defining the amount of weak acid, medium-strong acid, strong acid, and total acid of the catalyst according to the amount of hydrochloric acid consumed to absorb ammonia.

[0034] In the graded hydroisomerization dewaxing reactor of the present invention, preferably, the total acid amount 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; the content of medium-strong acid is 5-250 μmol / g, more preferably 10-220 μmol / g.

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

[0036] In the graded hydroisomerization dewaxing reactor of the present invention, preferably, along the material flow direction, the catalyst layer includes a first catalyst sublayer, a second catalyst sublayer and a third catalyst sublayer that are adjacent to each other in sequence;

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

[0038] With respect to the total acid amount of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer;

[0039] About Catalyst The molar percentage content of acid in the second catalyst sublayer is greater than that of the first catalyst sublayer and / or the third catalyst sublayer.

[0040] Specifically preferably, the total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content 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 medium-strong acid content is 10 to 60 μmol / g. The molar content of the 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% to 50%; more preferably, the total acid content is 200 to 300 μmol / g, the weak acid content is 50 to 100 μmol / g, and the medium-strong acid content is 150 to 200 μmol / g. The molar content of the acid is 30% to 50%;

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

[0043] It can be understood that in the present invention, the content of weak acid in the catalyst that contacts the material first is greater than the content of medium-strong acid, and the content of weak acid in the catalyst that contacts the material later is less than the content of medium-strong acid. At the same time, the total acid content of the catalyst increases first and then decreases, and the catalyst The molar content of acid increases first and then decreases.

[0044] In the graded 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 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%; 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%; the volume percentage content of the catalyst is 90% to 98%.

[0046] In the graded loading hydroisomerization dewaxing reactor of the present invention, preferably, the pore volume of the protective agent is 0.4-0.8 mL / g, and the specific surface area is 50-200 m 2 / g.

[0047] In the graded loading hydroisomerization dewaxing reactor of the present invention, preferably, the mass percentage content of active metal in the protective agent is 0-5%, and the rest is Al 2 O 3 and / or Al 2 O 3 -SiO 2 .

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

[0049] In the graded hydroisomerization dewaxing reactor of the present invention, preferably, along the material flow direction, the protective agent layer includes a first protective agent sublayer and a second protective agent sublayer adjacent to each other in sequence;

[0050] With respect to the active metal content of the protectant, the first protectant sublayer is less than or equal to the second protectant sublayer.

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

[0052] In the graded 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 m 2 / g; the pore volume of the protective agent in the second protective agent sublayer is 0.5 to 0.6 mL / g, and the specific surface area is 140 to 170 m 2 / g.

[0053] In the method of producing lubricating oil base oil from waste plastics of the present invention, firstly, the waste plastics are mixed with an organic solvent, the melting temperature of the waste plastics is effectively reduced, the melting process of the waste plastics is accelerated, and the viscosity of the melted waste plastics is also diluted. After filtering the melt system, the inorganic additives and inorganic impurities in the waste plastics are effectively removed, and the inorganic additives and inorganic impurities are prevented from entering the subsequent processing equipment to cause the equipment to be blocked, and the equipment maintenance cycle and maintenance costs are reduced; the fusible waste plastic raw material is mixed and processed with the wax oil after hydrogenation treatment, and the harsh difficulty of the waste plastic production lubricating oil base oil process is reduced, so that the waste plastics are processed by hydrogenation isomerization to produce a low pour point lubricating oil base oil with a high yield. At the same time, the present invention adopts a hydroisomerization dewaxing reactor with a specific gradation loading to carry out the hydroisomerization reaction, and the acid content and acid distribution in the catalyst are reasonably distributed, so that the overall catalytic efficiency of the protective agent and the catalyst is improved, the low temperature performance of the obtained base oil is further reduced, and the yield of the base oil is improved. In addition, the method of the present invention can also improve the viscosity index of the base oil. The present invention maximizes the economic benefits of recycling waste plastics and promotes the development of green and high value-added recycling applications of waste plastics. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0056] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0057] The present invention mainly utilizes waste plastics to produce lubricating base oil, removes inorganic additives and inorganic impurities in the waste plastics through pre-treatment of the waste plastics, and simultaneously adopts a hydroisomerization dewaxing reactor filled with a specific grading to maximize the use of waste plastics to produce high-value-added low pour point lubricating base oil.

[0058] Specifically, it includes two processes: pre-treatment of waste plastics and production of lubricant base oil:

[0059] Pretreatment of waste plastics:

[0060] The waste plastics are mixed with an organic solvent and heated until the fusible part of the waste plastics is completely melted to form a molten system; the molten system is filtered to remove infusible impurities, and then the organic solvent is recycled, and the remaining part is the fusible waste plastic raw material;

[0061] Production of lubricant base oils:

[0062] The fusible waste plastic raw material is mixed with the wax oil after hydrogenation treatment, and then enters a graded and loaded hydroisomerization dewaxing reactor under a hydrogen environment, flows through a protective agent layer and a catalyst layer in sequence to perform a hydroisomerization reaction to obtain a catalytic product; the catalytic product is fractionated to obtain a lubricating oil base oil;

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

[0064] Regarding the pretreatment process of waste plastics: the waste plastics and organic solvents are heated together to melt them, and then the molten system is filtered to filter out infusible solid impurities such as inorganic additives and inorganic impurities in the molten system, and then the organic solvent is recovered by flash evaporation for recycling, and the remaining part is obtained to obtain fusible waste plastic raw materials.

[0065] The present invention does not limit the type of waste plastics, for example, it can be hydrocarbon plastics, 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 at least one selected from pentane, cyclopentane, hexane, cyclohexane, octane, isooctane, heptane, benzene, toluene, xylene, and naphtha. Preferably, the mass ratio of the meltable waste plastic raw material to the hydrogenated wax oil is 2:(1-10).

[0067] According to the method of the present invention, preferably, the waste plastic is crushed into particles (e.g., with a particle size of 2 to 5 mm), mixed with an organic solvent, and then heated to 100 to 200° C. for melting, more preferably 140 to 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 treatment time is 30 to 120 minutes. The specific time can be determined according to the melting condition of the melting system. For example, when all the fusible waste plastics in the system are melted and the mass of the solid matter no longer decreases during the melting process, the melting treatment can be stopped to obtain a melting system. The present invention does not limit the specific reactor for the melting treatment, as long as the melting treatment can be stably carried out.

[0069] After the melting process is completed, the filtering process is started, and then the melting system is flash evaporated to recover the organic solvent therein. By recycling and reusing the organic solvent, the raw material cost of waste plastic recycling can be further reduced, so that the organic solvent can be reused.

[0070] In a specific embodiment, through thermogravimetric analysis, the decomposition initial temperature and decomposition termination temperature of the waste plastics are in the range of 100 to 500° C. In addition, in order to avoid corrosion to the reactor for melt processing, recycling of chlorine-containing waste plastics such as PVC is avoided as much as possible.

[0071] In the process of recycling waste plastics, the present invention first heats the waste plastics and an organic solvent together for melting treatment, which effectively reduces the melting temperature of the waste plastics, accelerates the melting process of the waste plastics, and also dilutes the viscosity of the melted waste plastics, so as to facilitate the filtering and impurity removal of the waste plastics. The obtained molten system is filtered to remove inorganic additives and other infusible solid impurities in the waste plastics from the molten system, so that the subsequent hydrogenation isomerization treatment process is more efficient.

[0072] Specifically, the removal of inorganic additives and other infusible solid impurities can ensure the efficient operation of the equipment in the subsequent processing process and avoid the phenomenon of equipment blockage and shutdown; on the one hand, it ensures the smooth progress of the recycling process and eliminates the risk of increased costs caused by stopping and restarting; on the other hand, it also reduces equipment maintenance costs and extends the equipment maintenance cycle. Therefore, the pretreatment process of the present invention is conducive to reducing the operating costs of enterprises and improving the economic benefits of enterprises. Especially important is that the removal of inorganic additives and other infusible solid impurities can also extend the catalytic activity and catalyst life of the catalyst in the hydroisomerization process, avoiding the catalytic performance degradation caused by catalyst pore structure blockage or active metal poisoning.

[0073] Regarding the production process of lubricating base oil: the fusible waste plastic raw material is evenly mixed with the wax oil after hydrogenation treatment, and the mixed system is further subjected to hydrogenation isomerization treatment to obtain high-quality lubricating base oil. Hydroisomerization is specifically carried out in a graded hydroisomerization dewaxing reactor. The mixed raw material enters the reactor under a hydrogen environment, flows through the protective agent layer and the catalyst layer in turn for hydrogenation isomerization reaction, and obtains a catalytic product; after the above-mentioned hydrogenation isomerization treatment, the catalytic product includes a large amount of lubricating base oil and a small amount of gasoline, diesel and gas products below C4. Therefore, the lubricating base oil can be further fractionated to obtain lubricating base oil, gasoline, diesel and products below C4 respectively.

[0074] The fusible waste plastic raw materials are mixed with the wax oil after hydrogenation treatment to produce lubricant base oil, which reduces the problems of high pour point and cloud point of base oil caused by the increased process severity of processing fusible waste plastic raw materials alone. The mixed processing process conditions of the fusible waste plastic raw materials and the wax oil after hydrogenation treatment are milder, and the yield of C4 and below gas products in the hydrogenation system is reduced and the yield of base oil is increased, thereby improving the overall economic benefits of the device for processing waste plastics, realizing high added value utilization of waste plastics, and improving the economic value of waste plastic recycling.

[0075] In the specific implementation process of the present invention, the mass content of the wax oil after hydrogenation treatment in the mixed system is generally controlled to be above 10%. Reasonable control of the amount of wax oil after hydrogenation treatment added to the mixed system is conducive to further reducing the process difficulty of processing waste plastics, so that waste plastics can be more efficiently converted into lubricating oil base oil. Therefore, the mass content of the wax oil after hydrogenation treatment in the mixed system can be controlled at 30% or more, that is, the mass ratio of the fusible waste plastic raw material to the wax oil after hydrogenation treatment is not higher than 2:1. The inventors have found that as the amount of wax oil after hydrogenation treatment increases within a certain range, the yield of the base oil obtained by recycling waste plastics first increases and the pour point of the base oil decreases, and then remains basically unchanged. Therefore, for economic considerations, the mass ratio of the fusible waste plastic raw material to the wax oil after hydrogenation treatment is generally 2: (1 to 10).

[0076] Of course, in the process of recycling waste plastics, the use of different waste plastics, organic solvents and hydrogenated wax oil will have an impact on the yield of base oil. Therefore, generally speaking, when the mass ratio of fusible waste plastic raw materials to hydrogenated wax oil is 2: (1-10), the excellent yield of base oil can be basically maintained.

[0077] Further, the distillation range of the hydrotreated wax oil of the present invention is 280 to 600°C, and more preferably 300 to 560°C. Exemplarily, the hydrotreated wax oil selects at least one of hydrotreated first-line wax oil, hydrotreated second-line wax oil, hydrotreated third-line wax oil, hydrotreated fourth-line 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. In order to ensure a high yield of the base oil, the sulfur content of the hydrotreated wax oil is ≤30μg / g, the nitrogen content is ≤15μg / g, and the final distillation point is not higher than 600°C.

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

[0079] The present invention adopts a graded 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 increases first and then decreases, and the catalyst The molar percentage content of acid in the total acid content first increases and then decreases.

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

[0081] The present invention adjusts the number and strength of the acid sites of the catalyst (especially Acid), can effectively adjust the distribution of products and the yield of base oil.

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

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

[0084] The carrier 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 carrier further contains at least one amorphous inorganic porous material, and the amorphous inorganic porous material includes aluminum oxide, silicon dioxide, zirconium oxide, titanium oxide and its composite oxide (aluminum oxide-silicon dioxide, zirconium oxide-silicon dioxide, titanium oxide-silicon dioxide, aluminum oxide-zirconium oxide, zirconium oxide-titanium oxide, aluminum oxide-titanium oxide). Based on the total mass of the catalyst, the mass proportion of the molecular sieve is preferably 40% to 80%, more preferably 55% to 75%; the mass proportion of the amorphous inorganic porous material is 19% to 59.9%, more preferably 25% to 50%.

[0085] The catalyst layer may be provided with catalysts with different acid amounts prepared from one type of molecular sieve, such as catalysts prepared from ZSM-22 molecular sieves with different acid amounts, or catalysts with different acid amounts prepared from different types of molecular sieves.

[0086] Preferably, the total acid content of the catalyst is 50-300 μmol / g, more preferably 100-300 μmol / g; the weak acid content is 10-150 μmol / g, more preferably 20-100 μmol / g; the medium-strong acid content is 5-250 μmol / g, more preferably 10-220 μmol / g. The molar percentage of the acid to the total acid content is preferably 5% to 50%.

[0087] The above catalysts are graded and loaded in the catalyst layer. Along the material flow direction, the total acid content of the catalyst increases first and then decreases. The molar content of acid increases first and then decreases.

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

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

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

[0091] It can be understood that in the present invention, the content of weak acid in the catalyst that contacts the material first is greater than the content of medium-strong acid, and the content of weak acid in the catalyst that contacts the material later is less than the content of medium-strong acid. At the same time, the total acid content of the catalyst increases first and then decreases, and the catalyst The molar content of acid increases first and then decreases.

[0092] Preferably, the total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content 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 medium-strong acid content is 10 to 60 μmol / g. The molar content of the acid is 5% to 15%.

[0093] 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% to 50%; more preferably, the total acid content is 200 to 300 μmol / g, the weak acid content is 50 to 100 μmol / g, and the medium-strong acid content is 150 to 200 μmol / g. The molar content of the acid is 30% to 50%.

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

[0095] By using the graded loading 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 produced by the catalytic reaction unit enter the fractionation equipment for base oil cutting to produce lubricating base oils of different viscosities.

[0096] It can be understood that in the present invention, the total acid amount of the catalyst in the first catalyst sublayer can be the same as or different from the total acid amount of the catalyst in the third catalyst sublayer, as long as the total acid amount of the catalyst can be increased first and then decreased along the material flow direction. The molar content of the acid and the third catalyst sublayer The molar content of the acid can be the same or different, as long as it can make the catalyst The molar content of the acid can be increased first and then decreased.

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

[0098] In the present 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 the catalyst layer, in at least one catalyst sublayer, The molar content of the acid is 5% to 50%. Further, in at least one catalyst sublayer, The molar content of the acid is 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 amount of the catalyst is 50 to 300 μmol / g. Furthermore, in at least one catalyst sublayer, the total acid amount 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 weak acid content of the catalyst is 10-150 μmol / g; and / or in at least one catalyst sublayer, the medium-strong acid content of the catalyst is 5-250 μmol / g.

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

[0103] In some embodiments of the present invention, in the protective agent layer in the hydroisomerization dewaxing reactor, 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.

[0104] In the hydroisomerization dewaxing reactor of the present invention, a protective agent layer is also provided before the catalyst layer. It is understood that the material first flows through the protective agent layer for impurity removal, and the impurity-removed material then flows through the catalyst layer for catalytic reaction. The present invention can convert the material into base oil to a greater extent by first removing impurities from the material and then carrying out the catalytic reaction, thereby improving the yield of the base oil, and can also reduce the impurity content in the base oil and improve 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%, and 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%, and 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 active metal content in the protective agent, the stronger the impurity removal ability of the protective agent (the stronger the desulfurization and denitrification ability). In the present invention, the active metal can be at least one of Co, Mo, Ni, and W. The mass percentage content of the active metal in the protective agent is 0-5%, and the rest is Al 2 O 3 and / or Al 2 O 3 -SiO 2 .

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

[0108] In the present invention, more than two protective agents may be arranged in the protective agent layer, and along the material flow direction, the pore volume between the protective agents gradually decreases or decreases in steps, and the specific surface area of ​​the protective agents gradually increases or increases in steps.

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

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

[0111] Exemplarily, along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer adjacent to each other in sequence;

[0112] With respect to the active metal content of the protectant, the first protectant sublayer is less than or equal to the second protectant sublayer.

[0113] For example, the active metal content of the protective agent in the first protective agent sublayer is 0-3wt%, the active metal content of the protective agent in the second protective agent sublayer is 1wt%-5wt%, the active metal in the protective agent is selected from one or a combination of Co, Mo, Ni, W, and the rest of the protective agent except the active metal is an amorphous inorganic porous material, preferably alumina (Al 2 O 3 ) and / or amorphous silicon aluminum (Al 2 O 3 -SiO 2 ).

[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 m 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 m 2 / g.

[0115] The technical scheme of the present invention will be further described below in conjunction with specific embodiments. All numerical values ​​specified therein (such as temperature, time, concentration and weight, including the range of each thereof) can generally be appropriately changed by (+) or (-) approximate values ​​in increments of 0.1 or 1.0. All numerical values ​​specified can be understood as being 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 gradations of the catalyst layer and the protective agent layer are shown in Table 1.

[0118] Table 1 Protective agent and catalyst properties and graded filling method

[0119]

[0120]

[0121]

[0122] Example 4

[0123] In this embodiment, waste plastics are mixed with hydrogenated four-line wax oil to obtain mixed oil 1A, including the following steps:

[0124] 1) 10 kg of polyethylene-propylene waste plastic particles (with a particle size of 2 to 5 mm) obtained by granulation with a granulator (through thermogravimetric characterization analysis, the initial decomposition temperature is 209° C., the 50% decomposition temperature is 337° C., the decomposition termination temperature is 416° C., and the melting range of the waste plastic is 95 to 128° C.) are added to a tank reactor with flash evaporation and stirring functions, and then 2 kg of heptane is added to the tank reactor, the tank reactor is sealed, the stirring function is turned on, and the reactor is heated to 180° C. and kept at a constant temperature for 90 minutes to obtain a molten system.

[0125] Subsequently, the molten system was filtered and weighed to obtain 0.16 kg of infusible solid. The remaining organic solvent was then recovered by flash evaporation and used to dissolve plastic next time, and the remaining part was meltable waste plastic raw material.

[0126] 2) The above-mentioned meltable waste plastic raw material and the hydrogenated four-line wax oil in Table 2 were uniformly mixed in a mass ratio of 2:1 to obtain mixed oil 1A. The relevant parameters of the mixed oil 1A are shown in Table 3.

[0127] Table 2 Properties of Hydrotreated Four-Line Wax Oil

[0128]

[0129] Table 3 Properties of Mixed Oil 1A

[0130]

[0131] Comparative Example 4

[0132] In this comparative example, waste plastics and unhydrogenated four-line wax oil are mixed to obtain mixed oil 1B. The difference from Example 4 is that the meltable waste plastics in Example 4 and the unhydrogenated four-line wax oil in Table 4 are uniformly mixed in a mass ratio of 2:1 to obtain the mixed oil 1B in Table 5.

[0133] The unhydrogenated reduced four-line wax oil in Table 4 is hydrogenated to obtain the hydrogenated reduced four-line wax oil in Table 2.

[0134] Table 4 Properties of unhydrogenated reduced-line wax oil

[0135]

[0136] It can be seen from Table 2 and Table 4 that compared with the hydrotreated reduced four-line wax oil, the unhydrotreated reduced four-line wax oil has a slightly larger density, higher initial and final distillation points, and more importantly, higher sulfur content, nitrogen content, iron and calcium metal impurities. Sulfur and nitrogen elements are poisons to the isomerization dewaxing catalyst. High content will cause the precious metals in the catalyst to be poisoned and deactivated; high content of metal impurities will cause the catalyst pore structure to be blocked, causing the catalyst to be deactivated.

[0137] Table 5 Properties of Mixed Oil 1B

[0138]

[0139] The sulfur content, nitrogen content, and iron and calcium metal impurities in mixed oil 1B are higher, making the isodewaxing catalyst easily deactivated.

[0140] Example 5

[0141] In this embodiment, waste plastics are mixed with hydrogenated first-line wax oil to obtain mixed oil 2A, including the following steps:

[0142] 1) 5 kg of polyethylene waste plastic and polybutene waste plastic obtained by granulation (particle size of 2-5 mm) by a granulator are mixed to form a mixed plastic, wherein the mass ratio of polyethylene waste plastic to polybutene waste plastic in the mixed plastic is 1:1, (thermogravimetric characterization and analysis of the mixed particles show that the initial decomposition temperature is 219° C., the 50% decomposition temperature is 348° C., the decomposition termination temperature is 435° C., and the melting range of the waste plastic is 101-142° C.). The mixed particles are added to a tank reactor with flash evaporation and stirring functions, and then 5 kg of cyclohexane is added to the tank reactor, the tank reactor is sealed, the stirring function is turned on, and the mixture is heated to 120° C. and kept at a constant temperature for 120 minutes 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 and used to dissolve plastic next time. Finally, the remaining part was the meltable waste plastic raw material.

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

[0145] Table 6 Properties of first-line wax oil after hydrotreatment

[0146]

[0147] Table 7 Properties of Mixed Oil 2A

[0148]

[0149] Comparative Example 5

[0150] In this comparative example, waste plastics and unhydrogenated first-line wax oil are mixed to obtain mixed oil 2B. The difference from Example 5 is that the meltable waste plastics in Example 5 and the unhydrogenated first-line wax oil in Table 8 are uniformly mixed in a mass ratio of 2:5 to obtain the mixed oil 2B in Table 9.

[0151] The unhydrogenated first-line wax oil in Table 8 was hydrogenated to obtain the hydrogenated first-line wax oil in Table 6.

[0152] Table 8 Properties of unhydrogenated first-line wax oil

[0153]

[0154] Table 9 Properties of Mixed Oil 2B

[0155]

[0156] It can be seen from Tables 6 and 8 that compared with the first-line wax oil after hydrogenation treatment, the first-line wax oil without hydrogenation treatment has a slightly larger density, higher initial and final distillation points, and more importantly, higher sulfur content, nitrogen content, iron and calcium metal impurities. Sulfur and nitrogen elements are poisons to the isomerization dewaxing catalyst. High content will cause poisoning of precious metals in the catalyst, thereby deactivating the catalyst; high content of metal impurities will cause blockage of the catalyst pore structure, causing catalyst deactivation.

[0157] Example 6

[0158] In this embodiment, waste plastics and hydrocracking tail oil are mixed to obtain mixed oil 3, which includes the following steps:

[0159] 1) 4 kg of polyethylene waste plastic obtained by granulation (with a particle size of 2 to 5 mm) by a granulator is mixed 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 characterization and analysis of the mixed plastic show that the initial decomposition temperature is 227°C, the 50% decomposition temperature is 352°C, the decomposition termination temperature is 448°C, and the melting range of the waste plastic is 101 to 142°C). The mixed plastic is added to a tank reactor with flash evaporation and stirring functions, and then 20 kg of naphtha is added to the tank reactor, the tank reactor is sealed, the stirring function is turned on, and the mixture is heated to 200°C. After maintaining the temperature for 30 minutes, a molten system is obtained.

[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 and used to dissolve plastic next time. Finally, the remaining part was meltable waste plastic raw material.

[0161] 2) The above-mentioned meltable waste plastic raw material and the hydrocracking tail oil in Table 10 were uniformly mixed in 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 Hydrocracking tail oil properties

[0163]

[0164] Table 11 Properties of Mixed Oil 3

[0165]

[0166] Comparative Example 6

[0167] In this comparative example, the mixed plastic particles of Example 6 were used for pretreatment without adding an organic solvent, and mixed 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 in Example 6 are added into the autoclave reactor without adding any organic solvent, the stirring function is turned on after sealing, and the mixture is heated to 200° C. and kept at a constant temperature for 30 minutes, and then the molten mixed waste plastic and the hydrocracking tail oil are uniformly mixed in 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 Mixed Oil 4

[0170]

[0171] Test 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) in the above Examples 4 to 6 and Comparative Examples 4 to 6 were subjected to hydroisomerization reaction in the six graded hydroisomerization dewaxing reactors in Table 1. The reaction process conditions of the hydroisomerization treatment are shown in Table 13.

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

[0174] Table 13 Hydroisomerization process conditions

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

[0176] Table 14 Product properties of hydroisomerization dewaxing reactors with different grading and filling methods for different mixed oils

[0177]

[0178]

[0179] Compared with the direct mixing of vacuum wax oil with molten plastic without hydrogenation treatment (mixed oil 1B and mixed oil 2B), the wax oil after hydrogenation treatment (mixed oil 1A and mixed oil 2A) is mixed with molten plastic, and the hydrogenation isomerization reaction is carried out through the isomerization dewaxing catalyst, so that the sulfur content, nitrogen content, pour point, cloud point and gas yield below C4 of the produced base oil are lower, and the base oil yield is higher. When the wax oil without hydrogenation treatment is mixed with molten plastic, the sulfur content and nitrogen content of the mixed raw material are too high, which will poison the isomerization dewaxing catalyst, and the isomerization dewaxing catalyst will be deactivated very quickly. At the same time, the sulfur content and nitrogen content of the produced base oil are too high, which is far higher than the index requirements of Class II and Class III base oils.

[0180] The hydroisomerization dewaxing reactor with graded filling as defined in Examples 1 to 3 is used to treat a mixed oil formed by hydrogenated wax oil and molten plastic or hydrocracking tail oil and molten plastic. The generated base oil has lower sulfur content, nitrogen content, pour point, cloud point and gas yield below C4, and higher base oil yield, which has higher technical advantages and good application prospects.

[0181] Test Example 2

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

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

[0184] Table 15 Hydroisomerization process conditions

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

[0186] Table 16 Product properties of different mixed oils using the hydroisomerization dewaxing reactor with the grading method of Example 3

[0187]

[0188] Test Example 3

[0189] The two mixed oils (mixed oil 3 and mixed oil 4) of Example 6 and Comparative Example 6 were subjected to hydroisomerization reaction in a hydroisomerization dewaxing reactor in the graded loading manner of Example 3 in Table 1. The reaction process conditions of the hydroisomerization treatment are shown in Table 17.

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

[0191] Table 17 Hydroisomerization process conditions

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

[0193] Table 18 Product properties of different mixed oils using the hydroisomerization dewaxing reactor with the grading filling method of Example 3

[0194]

[0195] In Experimental Examples 1, 2 and 3, the process conditions of the hydroisomerization treatment were changed, and the hydrogen-oil volume ratio was 200-800:1, the reaction temperature was 300-400°C, the reaction pressure (hydrogen partial pressure) was 6-15 MPa, and the volume space velocity was 0.5-2.0 h -1 Compared with the direct mixing of unhydrogenated wax oil and molten plastic or molten plastic without solvent treatment and hydrocracking tail oil, the mixed oil formed by hydrogenated wax oil and molten plastic or hydrocracking tail oil and solvent-treated molten plastic has lower sulfur content, nitrogen content, pour point, cloud point and gas yield below C4, and higher base oil yield, which has higher 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 limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for producing lubricating oil base oil using waste plastics, wherein: The method comprises the following steps: Pretreatment of waste plastics: The waste plastics are mixed with an organic solvent and heated until the fusible part of the waste plastics is completely melted to form a molten system; the molten system is filtered to remove infusible impurities, and then the organic solvent is recycled, and the remaining part is the fusible waste plastic raw material; Production of lubricant base oils: The fusible waste plastic raw material is mixed with the wax oil after hydrogenation treatment, and then enters a graded and loaded hydroisomerization dewaxing reactor under a hydrogen environment, flows through a protective agent layer and a catalyst layer in sequence to perform a hydroisomerization reaction to obtain a catalytic product; the catalytic product is fractionated to obtain a lubricating oil base oil; The protective agent layer is filled with protective agent, and the catalyst layer is filled with catalyst; along the material flow direction, the total acid content of the catalyst increases first and then decreases, and the catalyst The molar percentage content of acid in the total acid content first increases and then decreases.

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

3. The method according to claim 1, wherein: The waste plastics are crushed into particles, mixed with an organic solvent, and then heated to 100-200° C. for melting to form the melting system.

4. The method according to claim 1, wherein: The sulfur content of the hydrogenated wax oil is ≤30 μg / g, the nitrogen content is ≤15 μg / g, and the distillation range is 280-600°C.

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: Along the material flow direction, the catalyst layer includes a first catalyst sub-layer, a second catalyst sub-layer and a third catalyst sub-layer which are adjacent to each other in sequence; In the first catalyst sublayer, the content of weak acid is greater than that of medium-strong acid; in the second catalyst sublayer, the content of weak acid is less than that of medium-strong acid; in the third catalyst sublayer, the content of weak acid is less than that of medium-strong acid; With respect to the total acid amount of the catalyst, the second catalyst sublayer is greater than the first catalyst sublayer and / or the third catalyst sublayer; About Catalyst The molar percentage content of acid in the second catalyst sublayer is greater than that of the first catalyst sublayer and / or the third catalyst sublayer.

7. The method according to claim 6, wherein: The total acid content of the first catalyst sublayer is 50-200 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 10-80 μmol / g. The molar content of the acid is 5% to 20%; 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% to 50%; The total acid content of the third catalyst sublayer is 100-300 μmol / g, the weak acid content is 20-100 μmol / g, and the medium-strong acid content is 50-200 μmol / g. The molar content of the acid is 20% to 50%.

8. The method according to claim 1, wherein: 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.

9. The method according to claim 8, 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%.

10. The method according to claim 8, wherein: Along the material flow direction, the protective agent layer includes a first protective agent sub-layer and a second protective agent sub-layer adjacent to each other in sequence; The active metal content in the first protective agent sublayer is less than or equal to the active metal content in the second protective agent sublayer; The active metal content of the protective agent in the first protective agent sublayer is 0-3wt%, and the active metal content of the protective agent 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 m 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 m 2 / g.

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