Method for hydrogenation regeneration of waste lubricating oil and system for hydrogenation regeneration of waste lubricating oil

Abstract

The present disclosure relates to a method for hydrogenation regeneration of waste lubricating oil and a system for hydrogenation regeneration of waste lubricating oil, which comprises: S1, contacting waste lubricating oil, carbon carrier catalyst, promoter and circulating tail oil in a slurry bed for hydrogenation pretreatment to obtain a hydrogenation mixture; S2, fractionating the hydrogenation mixture to obtain gas, residue and distillate oil; S3, performing solid-liquid separation on the residue, and introducing the obtained liquid phase product into the slurry bed as the circulating tail oil; and contacting the distillate oil with a hydrogenation catalyst in a high-pressure fixed-bed hydrogenation device for high-pressure hydrogenation reaction. The method of the present disclosure can effectively remove metal and non-metallic heteroatoms in waste oil, and saturate part of condensed ring aromatic hydrocarbons, thereby reducing the severity of the subsequent processing process, and having a higher heavy oil utilization rate, and obtaining a base oil with higher quality.

Description

Technical Field

[0001] This disclosure relates to a method for hydrogenating and regenerating waste lubricating oil and a system for doing so. Background Technology

[0002] Waste lubricating oil refers to the waste oil generated during the operation of various mechanical equipment due to oxidation reactions, thermal decomposition, and the intrusion of contaminants, resulting in physicochemical properties exceeding usage standards. Statistics show that in 2022, China's lubricating oil production was 6.5106 million tons, generating approximately 2.9 million tons of waste lubricating oil. Waste lubricating oil contains carcinogens such as polycyclic aromatic hydrocarbons and heavy metals, and is classified as "special hazardous waste." If directly discharged without professional treatment, it will cause persistent pollution to the soil, water bodies, and other ecological environments, seriously threatening public health and safety.

[0003] It is worth noting that the base oil component, which constitutes a significant portion of waste lubricating oil, still possesses recycling value. Through modern refining processes, waste oil can be transformed into recycled lubricating oil products that meet industrial standards. Current market data shows that the price difference between recycled lubricating oil and virgin waste oil can reach 3-5 times. This significant price gradient not only reveals the important value of the circular economy but also fosters highly promising business opportunities. With increasingly stringent environmental policies and a deepening understanding of resource recycling, the waste lubricating oil recycling and processing industry has formed a multi-dimensional development pattern encompassing environmental governance, resource regeneration, and economic benefits, attracting widespread attention from enterprises and investors.

[0004] However, the quality of lubricating oil regenerated by hydrogenation of waste lubricating oil in the existing technology is not high, and the product color is poor. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method and system for hydrogenating and regenerating waste lubricating oil. This method can effectively remove metal and non-metal heteroatoms from waste oil and saturate some polycyclic aromatic hydrocarbons, reducing the severity of subsequent processing and achieving a high utilization rate of heavy oil, resulting in high-quality lubricating oil base oil.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a method for hydrogenating and regenerating waste lubricating oil, the method comprising:

[0007] S1. Waste lubricating oil, carbon-supported catalyst, accelerator and recycled tail oil are contacted in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0008] S2. Fractionate the hydrogenated mixture to obtain gas, residue and distillate oil;

[0009] S3. The residue is subjected to solid-liquid separation, and the resulting liquid product is introduced into the slurry bed as the circulating tail oil; in the high-pressure fixed-bed hydrogenation unit, the distillate oil is brought into contact with the hydrogenation catalyst to carry out a high-pressure hydrogenation reaction.

[0010] Optionally, in step S1, the reaction conditions for the hydrogen pretreatment include: a reaction temperature of 300-480℃, a reaction pressure of 2-25 MPa, and a liquid hourly space velocity of 0.2-4 h⁻¹. -1 The volume ratio of hydrogen to the lubricating oil is 100-3000 Nm³. 3 / m 3 .

[0011] Optionally, in step S1, the carbon-supported catalyst comprises a carbon-based support and an active metal component; based on the total weight of the carbon-supported catalyst and calculated by metal element, the content of the active metal component is 1-50% by weight.

[0012] The carbon-based carrier comprises carbon-containing materials with a carbon content greater than 80% by weight; the metal elements in the active metal component include one or more of Fe, Co, Mo, W and Ni.

[0013] Optionally, in step S1, the amount of the carbon-supported catalyst, calculated as metal element, relative to 1g of the waste lubricating oil is 20-10000μg, preferably 50-5000μg, and more preferably 100-3000μg.

[0014] Optionally, in step S1, the accelerator contains a sulfur-containing substance; preferably, the sulfur-containing substance is selected from one or more of carbon disulfide, sulfur, dimethyl disulfide and di-tert-butyl polysulfide.

[0015] The amount of the accelerator is 10-20000 μg relative to 1g of the waste lubricating oil, preferably 50-6000 μg.

[0016] Optionally, in step S2, the fractionation conditions include: an absolute pressure of 1-90 kPa, a bottom temperature of 320-370°C, and a cutting point between the distillate oil and the residue of 520-540°C.

[0017] Optionally, in step S3, along the flow direction of the distillate oil, the hydrogenation catalyst includes a hydrogenation protection catalyst and a hydrogenation treatment catalyst;

[0018] Based on the total volume of the hydrogenation catalyst and by volume, the amount of the hydrogenation protection catalyst is 10-50%, and the amount of the hydrogenation treatment catalyst is 50-90%.

[0019] Optionally, in step S3, along the flow direction of the distillate oil, the hydroprotection catalyst sequentially includes catalyst A, catalyst B, and catalyst C; based on the total volume of the hydroprotection catalyst, the content of catalyst A is 5-20%, the content of catalyst B is 10-50%, and the content of catalyst C is 30-85%.

[0020] The catalyst A contains a first hydrogenation active metal and a first support; the first hydrogenation active metal includes Group VB metals and Group VIB metals, and the first support is selected from alumina and / or silicon oxide; based on the total weight of the catalyst A and calculated as oxides, the content of the Group VB metal is less than 12% by weight, and the content of the Group VIB metal is 0.2-12% by weight; the first support contains phosphorus and halogens, based on the total weight of the first support, the phosphorus content is 0.1-8.0% by weight (calculated as P2O5), and the halogen content is 0.1-6% by weight (calculated as an element).

[0021] The catalyst B contains a second hydrogenation active metal and a second support; the second hydrogenation active metal includes a Group VIB metal and optionally a Group VIII metal, and the second support is selected from alumina and / or silica; based on the total weight of the catalyst B and calculated as oxides, the content of the Group VIB metal is greater than 0 and less than 4% by weight, and the content of the Group VIII metal is 0-0.8% by weight; the second support contains phosphorus and halogens, based on the total weight of the second support, the phosphorus content is 0.1-8.0% by weight (calculated as P2O5), and the halogen content is 0.1-6% by weight (calculated as an element).

[0022] The catalyst C contains a third hydrogenation active metal and a third support; the third hydrogenation active metal includes Group VIII metals and Group VIB metals, and the third support is selected from alumina and / or silica; based on the total weight of the catalyst C and calculated as oxides, the content of the Group VIB metal is 0.2-10% by weight, and the content of the Group VIII metal is less than 5% by weight; the third support contains phosphorus, and based on the total weight of the third support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight.

[0023] Preferably, the volume ratio of catalyst A, catalyst B and catalyst C is 1:(1-10):(1.5-17), more preferably 1:(2-5):(3-15).

[0024] Optionally, in step S3, along the flow direction of the distillate oil, the hydrotreating catalyst sequentially includes catalyst I and catalyst II;

[0025] The catalyst I comprises a hydrogenation catalyst Ia, which contains a first promoter, a fourth hydrogenation active metal component, and a fourth support. The first promoter comprises one or more of fluorine, boron, and phosphorus; the metal element in the fourth hydrogenation active metal component comprises one or more of Co, Mo, Ni, and W; the fourth support is selected from alumina and / or silicon oxide; based on the dry weight of the hydrogenation catalyst Ia, the content of the fourth hydrogenation active metal component, calculated as metal oxide, is 16-45% by weight, and the content of the first promoter is 0.5-10% by weight.

[0026] Preferably, the catalyst I further includes a hydrogenation catalyst Ib disposed upstream of the hydrogenation catalyst Ia; the hydrogenation catalyst Ib contains a fifth hydrogenation active metal component and a fifth support, and the content of the fifth hydrogenation active metal component is 2-15% by weight based on the dry weight of the hydrogenation catalyst Ib; the fifth hydrogenation active metal component is selected from one or more of Co, Mo, Ni and W; the fifth support is selected from alumina and / or silicon oxide;

[0027] Preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (3-10):1.

[0028] Optionally, in step S3, the second hydrogenation catalyst further includes catalyst II disposed downstream of catalyst I;

[0029] The catalyst II contains a second promoter, a sixth hydrogenation active metal component, and a sixth support. The second promoter includes boron and / or phosphorus. The content of the sixth hydrogenation active metal component, based on the dry weight of the catalyst II and calculated as metal oxide, is 16-52% by weight. The sixth hydrogenation active metal component is selected from one or more of Co, Mo, Ni, and W. The sixth support is selected from alumina and / or silicon oxide. The catalyst II is a fluorine-free hydrogenation catalyst, and the content of the second promoter is 2-8% by weight. The content of the sixth hydrogenation active metal component of the catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components of the catalyst I.

[0030] Preferably, the volume ratio of catalyst I to catalyst II is (30:70)-(60:40).

[0031] Optionally, in step S3, the conditions for the high-pressure hydrogenation reaction between the distillate oil and the hydrotreating protective catalyst include: a hydrogen partial pressure of 3-20 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature is 260-380℃, and the volume hourly space velocity is 0.2-5h. -1 ;

[0032] Preferably, the hydrogen partial pressure is 5-12 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3h. -1 .

[0033] Optionally, in step S3, the conditions for the high-pressure hydrogenation reaction between the distillate oil and the hydrotreating catalyst include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature of catalyst I is 260-420℃, and the volume hourly space velocity is 0.2-3h. -1 The reaction temperature of catalyst II is 240-380℃, and the volume hourly space velocity is 0.2-3h. -1 ;

[0034] Preferably, the hydrogen partial pressure is 5-20 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2h. -1 The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

[0035] The second aspect of this disclosure provides a system for the hydrogenation regeneration of waste lubricating oil using the method of the first aspect of this disclosure. The system includes: a slurry bed, a fractionation tower, a solid-liquid separation device, and a high-pressure fixed-bed hydrogenation device.

[0036] The product outlet of the slurry bed is in fluid communication with the inlet of the fractionation tower, the residue outlet of the fractionation tower is in fluid communication with the inlet of the solid-liquid separation device, the liquid outlet of the solid-liquid separation device is in flow communication with the inlet of the slurry bed, and the distillate oil outlet of the fractionation tower is in fluid communication with the inlet of the high-pressure fixed-bed hydrogenation device.

[0037] Optionally, along the flow direction of the material to be processed, the high-pressure fixed-bed hydrogenation device includes a hydrogenation protection reaction zone and a hydrogenation treatment reaction zone.

[0038] The advantages of this disclosure through the above technical solution are as follows:

[0039] (1) This disclosure uses a slurry bed to perform hydrogenation pretreatment on the entire fraction of waste lubricating oil, which can effectively remove metal and non-metal heteroatoms from the waste oil and saturate some polycyclic aromatic hydrocarbons, reducing the severity of subsequent processing. At the same time, this disclosure uses a carbon-supported catalyst, which can effectively reduce catalyst costs while ensuring the recovery and impurity removal requirements of the pretreatment liquid.

[0040] (2) The present invention performs solid-liquid separation on the residue obtained by fractionation of hydrogenated mixture, and uses the separated liquid phase product as circulating tail oil for hydrogen pretreatment again, which effectively improves the utilization rate of heavy oil.

[0041] (3) This disclosure achieves deep refining and regeneration of waste lubricating oil by subjecting distillate oil to high-pressure hydrogenation reaction, thereby obtaining high-quality regenerated lubricating oil base oil.

[0042] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0043] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0044] Figure 1 This is a flowchart illustrating a specific embodiment of the waste lubricating oil hydrogenation regeneration method disclosed herein. Detailed Implementation

[0045] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0046] like Figure 1 As shown, the first aspect of this disclosure provides a method for hydrogenating and regenerating waste lubricating oil. The method includes: S1, contacting waste lubricating oil, a carbon-supported catalyst, an accelerator, and recycled tail oil in a slurry bed for hydrogen pretreatment to obtain a hydrogenated mixture; S2, fractionating the hydrogenated mixture to obtain gas, residue, and distillate oil; S3, performing solid-liquid separation on the residue and introducing the obtained liquid phase product into the slurry bed as the recycled tail oil; and in a high-pressure fixed-bed hydrogenation unit, contacting the distillate oil with a hydrogenation catalyst to perform a high-pressure hydrogenation reaction.

[0047] This disclosed method treats the entire fraction of waste lubricating oil using a slurry-bed hydrotreating process. While ensuring high liquid yield, it achieves the removal of chlorine and heavy metals, optimizing catalyst protection conditions for subsequent high-pressure hydrorefining. Simultaneously, it employs tail oil recycling to improve the utilization rate of heavy oil. Combined with a high-pressure fixed-bed hydrotreating unit, it achieves deep refining and regeneration of waste lubricating oil, enabling the production of various grades of high-quality base oil products through subsequent separation processes such as vacuum distillation.

[0048] In one specific embodiment of this disclosure, the reaction conditions for the hydrogen pretreatment in step S1 include: a reaction temperature of 300-480℃, a reaction pressure of 2-25 MPa, and a liquid hourly space velocity of 0.2-4 h⁻¹. -1 The volume ratio of hydrogen to the lubricating oil (i.e., the hydrogen-to-oil volume ratio) is 100-3000 Nm³. 3 / m 3 Preferably, the reaction temperature is 350-420℃, the reaction pressure is 3-20MPa, and the liquid hourly space velocity is 0.25-3h. -1 The volume ratio of hydrogen to the lubricating oil is 200-1500 Nm³. 3 / m 3 .

[0049] In one specific embodiment of this disclosure, in step S1, the carbon-supported catalyst comprises a carbon-based support and an active metal component; based on the total weight of the carbon-supported catalyst and calculated by metal element, the content of the active metal component is 1-50% by weight, preferably 5-40% by weight, more preferably 20-40% by weight; the carbon-based support comprises carbon-containing materials with a carbon content greater than 80% by weight, and the carbon-based support may include, but is not limited to, carbon black, activated carbon, coal powder, deoiled asphalt, etc.; the metal element in the active metal component includes one or more of Fe, Co, Mo, W and Ni, and preferably, the active metal component includes metal oxides.

[0050] According to this disclosure, the accelerator contains sulfur-containing substances well known to those skilled in the art, such as carbon disulfide, sulfur, dimethyl disulfide, di-tert-butyl polysulfide, etc. In one specific embodiment, the amount of the accelerator relative to 1g of the waste lubricating oil is 10-20000μg, preferably 50-6000μg.

[0051] In one specific embodiment of this disclosure, in step S1, the amount of the carbon-supported catalyst, calculated as metal element, is 20-10000 μg, preferably 50-5000 μg, and more preferably 100-3000 μg, relative to 1g of the waste lubricating oil.

[0052] In one specific embodiment of this disclosure, in step S1, superheated steam and / or alkaline solution are introduced into the slurry bed to slow down coking in the heating furnace and to facilitate the dechlorination treatment of waste lubricating oil.

[0053] In one specific embodiment of this disclosure, the fractionation conditions in step S2 include: an absolute pressure of 1-90 kPa and a bottom temperature of 320-370°C; the cutoff point between the distillate oil and the residue is 520-540°C. In one embodiment, the distillation range of the distillate oil is 300-540°C, preferably 320-520°C. In this embodiment, the total metal content of the distillate oil is not greater than 20 μg / g, the content of n-heptane insolubles is not greater than 150 μg / g, and the chlorine content is not greater than 15 μg / g. In this disclosure, by controlling the reaction conditions of the hydrogen pretreatment and using a carbon-supported catalyst, the conversion rate of the lubricating oil base oil fraction (280-520°C) in waste lubricating oil can be no higher than 15%, and the yield of the lubricating oil base oil fraction obtained from the regeneration process is high.

[0054] In one specific embodiment of this disclosure, in step S3, along the flow direction of the distillate oil, the hydrogenation catalyst includes a hydrogenation protection catalyst and a hydrogenation treatment catalyst; based on the total volume of the hydrogenation catalyst and by volume, the amount of the hydrogenation protection catalyst is 10-50%, and the amount of the hydrogenation treatment catalyst is 50-90%.

[0055] According to this disclosure, a variety of catalyst gradations are used in the high-pressure fixed-bed hydrogenation unit. In one specific embodiment of this disclosure, in step S3, along the flow direction of the distillate oil, the hydrogenation protection catalyst sequentially includes catalyst A, catalyst B, and catalyst C; based on the total volume of the hydrogenation protection catalyst, the content of catalyst A is 5-20%, the content of catalyst B is 10-50%, and the content of catalyst C is 30-85%.

[0056] The catalyst A contains a first hydrogenation active metal and a first support; the first hydrogenation active metal includes a Group VB metal and a Group VIB metal, and the first support is selected from alumina and / or silicon oxide; based on the total weight of the catalyst A and calculated as oxides, the content of the Group VB metal is less than 12% by weight, preferably 1-8% by weight, and the content of the Group VIB metal is 0.2-12% by weight, preferably 5-10% by weight; the first support contains phosphorus and halogens, based on the total weight of the first support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight, preferably 0.1-5.0% by weight, and the halogen content calculated as an element is 0.1-6% by weight, preferably 0.5-2.5% by weight.

[0057] The catalyst B contains a second hydrogenation active metal and a second support; the second hydrogenation active metal includes a Group VIB metal and optionally a Group VIII metal, and the second support is selected from alumina and / or silica; based on the total weight of the catalyst B and calculated as oxides, the content of the Group VIB metal is greater than 0 and less than 4% by weight, preferably 1.5-4% by weight, and the content of the Group VIII metal is 0-0.8% by weight, preferably 0-0.6% by weight; the second support contains phosphorus and halogens, based on the total weight of the second support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight, preferably 0.1-5% by weight, and the halogen content calculated as an element is 0.1-6% by weight, preferably 0.5-2.5% by weight.

[0058] The catalyst C contains a third hydrogenation active metal and a third support; the third hydrogenation active metal includes Group VIII metals and Group VIB metals, and the third support is selected from alumina and / or silica; based on the total weight of the catalyst C and calculated as oxides, the content of the Group VIB metal is 0.2-10% by weight, preferably 4-8% by weight, and the content of the Group VIII metal is less than 5% by weight, preferably 0.2-4% by weight; the third support contains phosphorus, and based on the total weight of the third support and calculated as P2O5, the phosphorus content is 0.1-8.0% by weight, preferably 0.1-5% by weight.

[0059] In a preferred embodiment of this disclosure, the volume ratio of catalyst A, catalyst B and catalyst C is 1:(1-10):(1.5-17), preferably 1:(2-5):(3-15).

[0060] In one specific embodiment of this disclosure, along the flow direction of the distillate oil, the hydrotreating catalyst sequentially comprises catalyst I and catalyst II;

[0061] The catalyst I comprises a hydrogenation catalyst Ia, which contains a first promoter, a fourth hydrogenation active metal component, and a fourth support. The first promoter comprises one or more of fluorine, boron, and phosphorus. The metal element in the fourth hydrogenation active metal component comprises one or more of Co, Mo, Ni, and W. The fourth support is selected from alumina and / or silicon oxide. Based on the dry weight of the hydrogenation catalyst Ia, the content of the fourth hydrogenation active metal component, calculated as metal oxide, is 16-45% by weight, preferably 22-32% by weight, and the content of the first promoter is 0.5-10% by weight, preferably 0.8-8% by weight.

[0062] In one specific embodiment of this disclosure, catalyst I further includes a hydrogenation catalyst Ib disposed upstream of the hydrogenation catalyst Ia; the hydrogenation catalyst Ib contains a fifth hydrogenation active metal component and a fifth support, and the content of the fifth hydrogenation active metal component is 2-15% by weight based on the dry weight of the hydrogenation catalyst Ib; the fifth hydrogenation active metal component is selected from one or more of Co, Mo, Ni and W; the fifth support is selected from alumina and / or silica; the content of the fifth hydrogenation active metal component in the hydrogenation catalyst Ib is less than the content of the fourth hydrogenation active metal component in the hydrogenation catalyst Ia; preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (3-10):1. The above-described gradation scheme of the hydrogenation protection catalyst and the hydrogenation treatment catalyst of this disclosure not only extends the operating cycle of the unit but also increases the depth of hydrorefining and improves the quality of the base oil.

[0063] In one specific embodiment of this disclosure, the catalyst II is a fluorine-free hydrogenation catalyst, which can be commercially available or prepared in-house. Commercially available catalyst II can be, for example, a catalyst with the designation RJW-2 or RJW-3.

[0064] In a preferred embodiment, catalyst II comprises a second promoter, a sixth hydrogenation active metal component, and a sixth support. The second promoter includes boron and / or phosphorus. Based on the dry weight of catalyst II, the content of the sixth hydrogenation active metal component, calculated as metal oxide, is 16-52% by weight, preferably 22-46% by weight. The sixth hydrogenation active metal component is selected from one or more of Co, Mo, Ni, and W. The sixth support is selected from alumina and / or silicon oxide. Catalyst II is a fluorine-free hydrogenation catalyst. The content of the second promoter is 0-10% by weight, preferably 2-8% by weight. The content of the sixth hydrogenation active metal component in catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components in catalyst I.

[0065] According to this disclosure, in step S3, the solid-liquid separation can be performed using methods well known to those skilled in the art, such as one or more combinations of filtration separation, centrifugal separation, membrane separation, and solvent extraction separation, to separate the waste catalyst and heavy oil from the residue. In one specific embodiment of this disclosure, the solid-liquid separation is performed using solvent extraction separation, where the residue is contacted with an extractant for solvent extraction separation; the conditions for solvent extraction separation include: a temperature of 40-300°C; a pressure of 0.1-14 MPa; and the amount of extractant used relative to 1 part by weight of residue is 1-10 parts by weight, preferably 1-5 parts by weight. The extractant can be anything well known to those skilled in the art, such as at least one of C3-C8 alkanes, C3-C8 olefins, toluene, and light naphtha, preferably selected from C3-C5 alkanes and / or toluene.

[0066] In one specific embodiment of this disclosure, the total metal content in the circulating tail oil is no more than 20 μg / g, and the n-heptane insoluble matter is no more than 150 μg / g.

[0067] In one specific embodiment of this disclosure, in step S3, the conditions for the high-pressure hydrogenation reaction in which the distillate oil contacts the hydrotreating protective catalyst include: a hydrogen partial pressure of 3-20 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature is 260-380℃, and the volume hourly space velocity is 0.2-5h. -1 Preferably, the hydrogen partial pressure is 5-12 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3h. -1 .

[0068] According to this disclosure, there can be one or more high-pressure hydrogenation units, with multiple high-pressure hydrogenation units connected in series. In one specific embodiment of this disclosure, in step S3, the conditions for the high-pressure hydrogenation reaction between the distillate oil and the hydrotreating catalyst include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature of catalyst I is 260-420℃, and the volume hourly space velocity is 0.2-3h. -1 The reaction temperature of catalyst II is 240-380℃, and the volume hourly space velocity is 0.2-3h. -1 Preferably, the hydrogen partial pressure is 5-20 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2h. -1The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

[0069] In one specific embodiment of this disclosure, the method further includes step S4: introducing the reaction product obtained from the high-pressure hydrogenation reaction into a product fractionation tower for fractionation to obtain gas, hydrogenated diesel oil, and lubricating oil base oil.

[0070] like Figure 1 As shown, the second aspect of this disclosure provides a system for the hydrogenation regeneration of waste lubricating oil using the method of the first aspect of this disclosure. The system includes: a slurry bed, a fractionation tower, a solid-liquid separation device, and a high-pressure fixed-bed hydrogenation device; the product outlet of the slurry bed is fluidly connected to the inlet of the fractionation tower, the residue outlet of the fractionation tower is fluidly connected to the inlet of the solid-liquid separation device, the liquid outlet of the solid-liquid separation device is fluidly connected to the inlet of the slurry bed, and the distillate oil outlet of the fractionation tower is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

[0071] In one specific embodiment of this disclosure, the high-pressure fixed-bed hydrogenation device includes a hydrogenation protection reaction zone and a hydrogenation treatment reaction zone along the flow direction of the material to be treated.

[0072] The present disclosure is further described in detail below through examples.

[0073] The properties of the waste lubricating oil regenerated in the following examples and comparative examples are shown in Table 1. Unless otherwise specified, all reagents used were commercially available.

[0074] Table 1 Properties of waste lubricating oil

[0075]

[0076]

[0077] The carbon-supported catalyst C1 in the slurry bed was prepared by the following method:

[0078] (1) Preparation of carrier: Activated carbon (carbon content of more than 95% by weight) is dried and dehydrated at 120℃ and then pulverized into powder with a particle size of 20-60μm;

[0079] (2) Using Fe2(SO4)3 to prepare an aqueous solution of ferric sulfate as the metal source solution, the Fe content in the aqueous solution of ferric sulfate is 2.4g relative to 100mL of active metal source solution; after mixing 125mL of aqueous solution of ferric sulfate with 5g of carrier evenly, 20.16g of 28wt% ammonia solution is added while stirring to carry out precipitation reaction; the precipitation reaction conditions are: reaction temperature of 60℃ and reaction time of 60min; after washing the precipitate, the precipitate reaction product is subjected to solid-liquid separation to obtain solid material;

[0080] (3) After drying the solid material at 110℃ for 300 min, it was placed in a tube furnace and calcined at 490℃ for 300 min under N2 gas protection to obtain carbon-supported catalyst C1, the properties of which are shown in Table 2.

[0081] The preparation method of carbon-supported catalyst C2 is similar to that of carbon-supported catalyst C1. The difference is that in step (3), carbon-supported catalyst C2 is obtained after drying at 110℃ for 300 min and is no longer placed in a tube furnace for calcination. Its properties are shown in Table 2.

[0082] Table 2 Properties of carbon-supported catalysts C1 and C2

[0083]

[0084]

[0085] Example 1

[0086] S1. Waste lubricating oil, carbon-supported catalyst, accelerator and recycled tail oil are contacted in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0087] S2. Fractionate the hydrogenated mixture to obtain gas, residue and distillate oil;

[0088] S3. The residue is subjected to solid-liquid separation, and the resulting liquid product is introduced into the slurry bed as circulating tail oil; in the high-pressure fixed-bed hydrogenation unit, the distillate oil is brought into contact with the hydrogenation catalyst to carry out a high-pressure hydrogenation reaction.

[0089] The reaction conditions, product results, and product property analysis results for the above steps are shown in Table 5.

[0090] Along the flow direction of the distillate oil, the hydrotreating catalyst includes a hydroprotection catalyst and a hydrotreatment catalyst. Along the flow direction of the distillate oil, the hydroprotection catalyst includes catalyst A, catalyst B, and catalyst C; the composition of the catalysts is shown in Table 3.

[0091] Catalyst A contains 8.0 wt% WO3, 1.6 wt% V2O5, and the balance support. Based on the dry weight of the support, the phosphorus content (calculated as P2O5) is 2.9 wt%, and the fluorine content (calculated as halogens) is 1.0 wt%.

[0092] The solution was prepared as follows: 2 L of aluminum sulfate solution with an Al2O3 concentration of 50 g / L was prepared, and 6 mL of concentrated phosphoric acid and 25 g of magnesium sulfate heptahydrate were added to obtain an aluminum sulfate solution containing phosphorus and magnesium. 20 mL of water glass solution with a SiO2 content of 250 g / L and a modulus of 2.8 was added to 2 L of sodium aluminate solution with an alumina content of 200 g / L and a caustic coefficient of 1.58. The above-mentioned aluminum sulfate solution containing phosphorus and magnesium compounds and the above-mentioned sodium aluminate solution containing water glass were reacted and precipitated in a 5 L reaction vessel. The precipitate was then filtered (XRD characterization showed that the hydrated alumina precipitate had an amorphous structure). The reaction temperature was 50 °C, and the flow rate of the sodium aluminate solution was controlled to maintain the pH of the reaction system at 4.8. In a 5-liter reaction vessel, filter cake, deionized water, and ammonium carbonate (chemically pure, product of Beijing Yili Fine Chemicals Co., Ltd.) were mixed and slurried. The amount of ammonium carbonate was adjusted to make the pH of the slurry 8.7. The slurry was aged at 40°C for 5 hours and then filtered. The filter cake was washed twice with deionized water and dried at 120°C for 24 hours to obtain hydrated alumina P4. P4 was characterized by XRD and showed to have a pseudoboehmite structure. P4 was calcined at 600°C for 4 hours to obtain alumina A4. A4 was characterized by XRD and showed to have a γ-alumina structure.

[0093] Weigh 1000g of the hydrated alumina P4 prepared in the previous step, add 1440ml of an aqueous solution containing 10ml of nitric acid (a product of Tianjin Chemical Reagent Factory No. 3) and 9.8g of ammonium fluoride, and extrude it into a diameter of [missing value] on a twin-screw extruder. The butterfly-shaped strip. The wet strip was dried at 120°C for 4 hours to obtain the molded article, and the molded article was calcined at 600°C for 3 hours to obtain the carrier Z4.

[0094] Take 200 g of support Z4, impregnate it for 1 hour with 220 mL of a mixed solution of ammonium tungstate and ammonium vanadate containing 80 g / L WO3 and 16 g / L V2O5, dry it at 120 °C for 4 hours, and calcine it at 400 °C for 3 hours to obtain hydrogenation catalyst A.

[0095] Catalyst B contains 3.0 wt% MoO3, 0.5 wt% NiO, and the balance support. Based on the dry weight of the support, the phosphorus content (calculated as P2O5) is 1.8 wt%, and the fluorine content (calculated as halogens) is 1.0 wt%.

[0096] The alumina was prepared as follows: 2 L of aluminum sulfate solution with an Al2O3 concentration of 90 g / L was prepared, and 3 mL of concentrated phosphoric acid, 12 g of magnesium sulfate heptahydrate, and 10 g of boric acid were added to obtain an aluminum sulfate solution containing phosphorus, magnesium, and boron. The above aluminum sulfate solution and an 8% ammonia solution were added in parallel flow to a 5 L reaction vessel to allow precipitation. The precipitate was then filtered (XRD characterization showed the hydrated alumina precipitate to be amorphous). The reaction temperature was 55 °C, and the flow rate of the ammonia solution was controlled to maintain the pH of the reaction system at 6.2. In a 2-liter reaction vessel, filter cake, deionized water, and sodium carbonate were mixed and slurried. The amount of sodium carbonate was adjusted to a pH of 8.9. The slurry was aged at 38°C for 30 minutes and then filtered. The filter cake was washed twice with deionized water and dried at 120°C for 14 hours to obtain hydrated alumina P3. XRD characterization showed that P3 had a boehmite-like structure. P3 was calcined at 600°C for 4 hours to obtain alumina A3. XRD characterization showed that A3 had a γ-alumina structure. 1000g of the prepared hydrated alumina P3 was weighed and added to 1440ml of an aqueous solution containing 10ml of nitric acid (from Tianjin Chemical Reagent Factory No. 3) and 9.8g of ammonium fluoride. The mixture was extruded on a twin-screw extruder to form a product with an outer diameter of [missing information]. The butterfly-shaped strip. The wet strip is dried at 120°C for 4 hours to obtain the molded article, and the molded article is calcined at 600°C for 3 hours to obtain the carrier Z3.

[0097] Take 200 g of Z3, impregnate it for 1 hour with 220 mL of a mixed solution of ammonium heptamolybdate and nickel nitrate containing 28.8 g / L MoO3 and 5 g / L NiO, dry it at 120 °C for 4 hours, and calcine it at 400 °C for 3 hours to obtain catalyst B.

[0098] Catalyst C contains 6.0 wt% WO3, 1.0 wt% CoO, and the balance being a support. Based on the total weight of the support, the phosphorus content, calculated as P2O5, is 2.5 wt%.

[0099] The solution was prepared as follows: 2 L of aluminum nitrate solution with an Al2O3 concentration of 50 g / L was prepared, and 5 mL of phosphoric acid was added to obtain an aluminum nitrate solution containing phosphorus. The above aluminum nitrate solution and a sodium aluminate solution containing 200 g / L alumina and a caustic coefficient of 1.58 were added concurrently to a 5 L reaction vessel to induce precipitation. The precipitate was then filtered (XRD characterization showed the hydrated alumina precipitate to be amorphous). The reaction temperature was 60 °C, and the flow rate of the sodium aluminate solution was controlled to maintain the pH of the reaction system at 6.0. In a 5-liter reaction vessel, filter cake, deionized water, and ammonium bicarbonate (chemically pure, product of Beijing Yili Fine Chemicals Co., Ltd.) were mixed and slurried. The amount of ammonium bicarbonate was adjusted to make the pH of the slurry 8.0. After aging at 55℃ for 4 hours, the slurry was filtered. The filter cake was washed twice with deionized water and dried at 120℃ for 24 hours to obtain hydrated alumina P6. XRD characterization showed that P6 had a pseudoboehmite structure. P6 was calcined at 600℃ for 4 hours to obtain alumina A6. 1000g of P6 was weighed and added to 1440ml of an aqueous solution containing 10ml of nitric acid (product of Tianjin Chemical Reagent Factory No. 3). The mixture was extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm on a twin-screw extruder. The wet strip was dried at 120℃ for 4 hours to obtain a molded product. The molded product was calcined at 600℃ for 3 hours to obtain carrier Z6.

[0100] Take 200g of the support Z6 prepared above, impregnate it with 220ml of a mixed solution of ammonium heptamolybdate and cobalt nitrate containing WO3 59g / L, CoO 10g / L for 1 hour, dry it at 120℃ for 4 hours, and calcine it at 400℃ for 3 hours to obtain catalyst C.

[0101] Table 3 Composition of catalysts A, B, and C

[0102]

[0103] Along the flow direction of the distillate oil, the hydrotreating catalysts include hydrotreating catalyst Ib, hydrotreating catalyst Ia, and hydrotreating catalyst II. The composition of the catalysts is shown in Table 4.

[0104] The hydrogenation catalyst Ia contains 7% by weight NiO, 20% by weight MoO3, 5% by weight WO3, 2% by weight P2O5 and the balance silica-alumina support.

[0105] The following method was used to prepare solution I (pH 0.69, Al2O3 content 94 g / L) by dissolving 3127 g of Al2(SO4)3·18H2O, 1.75 g of ferrous sulfate, and 338 g of 98 wt% sulfuric acid in 4968 g of deionized water). Solution II (containing 60 g / L SiO2, pH 12.44) was prepared by diluting 2070 g of water glass solution with water. Solution II was then added to solution I under vigorous stirring to prepare a transparent silicon-aluminum mixed solution III with a pH of 2.7 and a SiO2 / Al2O3 mass ratio of 2.0. Dilute ammonia (containing 8 wt% NH3) was mixed with solution III under a stirring speed of 2000 RPM, with the ammonia added at a rate adjusted to maintain the pH of the mixture within the range of 8.0 ± 0.3. After the ammonia water was added, the resulting product was stirred at 55-60℃ for 5 hours, filtered, and the resulting filter cake was mixed with hot deionized water and filtered. This step was repeated 4 times. The filter cake was dried at 120℃ overnight. The precursor SAS-4 of the silicon-aluminum composite material carrier was obtained. Based on the weight of the added ferrous sulfate and the obtained precursor SAS-4, the iron content in the precursor of the silicon-aluminum composite material carrier, calculated as Fe2O3, was 0.2% by weight.

[0106] 1000 grams of the precursor of the above-mentioned silicon-aluminum composite material carrier SAS-4 was extruded into strips to obtain clover-shaped strips with a diameter of 1.3 mm. The wet clover-shaped strips were then dried at 120°C for 4 hours and then calcined in a tube furnace at 600°C for 4 hours with air to obtain catalyst carrier strips.

[0107] Concentrated phosphoric acid (85 wt%, analytical grade, Beijing Chemical Plant, hereinafter the same) and deionized water were heated to 75°C and then mixed with basic nickel carbonate (industrial grade, from Changling Catalyst Plant, hereinafter the same) and molybdenum trioxide (industrial grade, from Changling Catalyst Plant, hereinafter the same). The mixture was heated and stirred until dissolved, and the solution became clear and transparent. After cooling to room temperature, solution I was obtained. Ammonium metatungstate (industrial grade, Sichuan Zigong Hard Alloy Plant, hereinafter the same) and nickel nitrate (analytical grade, Beijing Shuanghuan Chemical Reagent Plant, hereinafter the same) were added to deionized water and stirred until dissolved, resulting in solution II. Solution I and solution II were mixed at room temperature and adjusted to 160 mL with deionized water to obtain solution III (the amounts of NiO, WO3, MoO3 and P2O5 were prepared according to 7 wt%, 20 wt%, 5 wt% and 2 wt%, respectively). 200 g of the above support strip was impregnated with solution III for 2 hours, then the support strip was removed and dried at 120°C for 4 hours, and then calcined at 500°C with air for 4 hours to obtain hydrogenation catalyst Ia.

[0108] The hydrogenation catalyst Ib uses commercially available RG-1 catalyst, produced by Changling Catalyst Factory, containing 1.0 wt% NiO, 5.5 wt% MoO3 and the balance alumina support.

[0109] Hydrogenation catalyst II contains 6.7 wt% NiO, 32.0 wt% WO3, 6.2 wt% MoO3, 5.9 wt% P2O5 and the balance alumina support.

[0110] It was prepared by the following method: 200.0 g of industrial alumina support was weighed and impregnated with 178 mL of an aqueous solution containing 31.2 g of ammonium paramolybdate for 3 hours, dried at 120°C for 4 hours, and then impregnated with 168 mL of an aqueous solution containing 108.2 g of nickel nitrate, 151.3 g of ammonium metatungstate, and 48.7 g of phosphoric acid for 3 hours, dried at 120°C for 4 hours, and calcined at 450°C for 4 hours to obtain catalyst II.

[0111] Table 4 Composition of hydrogenation catalysts Ia, II, and Ib

[0112]

[0113] Examples 2-8

[0114] Waste lubricating oil was treated using the same method as in Example 1, except that the reaction conditions were different, as shown in Table 5.

[0115] Comparative Example 1

[0116] Waste lubricating oil was processed using a conventional vacuum fractionation-hydrorefining process. The properties of the base oil intermediates obtained from vacuum fractionation are shown in Table 6. The yield of the base oil intermediates after vacuum fractionation was 82%. After hydrorefining, the yield of the base oil was approximately 95%. Specific process parameters are shown in Table 7.

[0117] Table 5

[0118]

[0119]

[0120]

[0121] In the table, catalyst dosage (μg / g) refers to the amount of carbon-supported catalyst, calculated as metal element, relative to 1g of the waste lubricating oil. Accelerator dosage (μg / g) refers to the amount of accelerator relative to 1g of the waste lubricating oil.

[0122] Catalyst I includes hydrogenation catalyst Ia and hydrogenation catalyst Ib. The reaction conditions for hydrogenation catalyst Ia and hydrogenation catalyst Ib are the same, as shown in the table for catalyst I.

[0123] Table 6

[0124]

[0125]

[0126] Table 7

[0127] Distillation pretreatment conditions Pressure / kPa -95 Tower bottom temperature / ℃ 365 Distillation range of distillate oil / °C 320～520 Preprocessing results Naphtha + Diesel Yield + Tailings / % 15.0 150N base oil fraction yield / % 82.0 Total metals in 150N base oil distillate (μg / g) ＜5.0 150N base oil fraction n-heptane insoluble matter / (μg / g) 320 Hydrogenation protection catalyst reaction conditions A:B:C (volume ratio) 5:20:75 Reaction conditions Reaction temperature / °C 250 Reaction pressure / MPa 15.0 <![CDATA[Volume hourly space velocity / h -1 > 1.0 <![CDATA[hydrogen to oil volume ratio / Nm 3 / m 3 > 1000 Hydrogenation catalyst reaction conditions Ib:Ia:II (volume ratio) 10:40:50 Catalyst I Reaction temperature / °C 270 Reaction pressure / MPa 15.0 <![CDATA[Volume space velocity / h -1 > 0.75 <![CDATA[hydrogen to oil volume ratio / Nm 3 / m 3 > 1000 Catalyst II Reaction temperature / °C 270 Reaction pressure / MPa 15.0 <![CDATA[Volume space velocity / h -1 > 0.6 <![CDATA[hydrogen-to-oil volume ratio / Nm 3 / m 3 > 1000 Product Results Base oil yield / % 95.0 Product Nature <![CDATA[Kinematic viscosity at 40°C mm 2 / s]]> 29.2 Color / Cyber ​​Feature 24 Oxidation stability (rotating oxygen bomb method), min 260

[0128] As can be seen from the above, the method disclosed herein can effectively remove metal and non-metal heteroatoms from waste oil, and can produce lubricating oil base oil with a high total yield.

[0129] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0130] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0131] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for hydrogenating and regenerating waste lubricating oil, the method comprising: S1. Waste lubricating oil, carbon-supported catalyst, accelerator and recycled tail oil are contacted in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture; S2. Fractionate the hydrogenated mixture to obtain gas, residue and distillate oil; S3. The residue is subjected to solid-liquid separation, and the resulting liquid product is introduced into the slurry bed as the circulating tail oil. In a high-pressure fixed-bed hydrogenation unit, the distillate oil is brought into contact with a hydrogenation catalyst to carry out a high-pressure hydrogenation reaction.

2. The method according to claim 1, wherein, In step S1, the reaction conditions for the hydrogen pretreatment include: a reaction temperature of 300-480℃, a reaction pressure of 2-25MPa, and a liquid hourly space velocity of 0.2-4h. -1 The volume ratio of hydrogen to the lubricating oil is 100-3000 Nm³. 3 / m 3 .

3. The method according to claim 1, wherein, In step S1, the carbon-supported catalyst comprises a carbon-based support and an active metal component; based on the total weight of the carbon-supported catalyst and calculated by metal element, the content of the active metal component is 1-50% by weight. The carbon-based carrier comprises carbon-containing materials with a carbon content greater than 80% by weight; the metal elements in the active metal component include one or more of Fe, Co, Mo, W and Ni.

4. The method according to claim 1, wherein, In step S1, the amount of the carbon-supported catalyst, calculated as metal element, is 20-10000 μg relative to 1g of the waste lubricating oil, preferably 50-5000 μg, and more preferably 100-3000 μg.

5. The method according to claim 1, wherein, In step S1, the accelerator contains a sulfur-containing substance; preferably, the sulfur-containing substance is selected from one or more of carbon disulfide, sulfur, dimethyl disulfide and di-tert-butyl polysulfide. The amount of the accelerator is 10-20000 μg relative to 1g of the waste lubricating oil, preferably 50-6000 μg.

6. The method according to claim 1, wherein, In step S2, the fractionation conditions include: an absolute pressure of 1-90 kPa, a bottom temperature of 320-370°C, and a cutting point between the distillate oil and the residue of 520-540°C.

7. The method according to claim 1, wherein, In step S3, along the flow direction of the distillate oil, the hydrogenation catalyst includes a hydrogenation protection catalyst and a hydrogenation treatment catalyst; Based on the total volume of the hydrogenation catalyst and by volume, the amount of the hydrogenation protection catalyst is 10-50%, and the amount of the hydrogenation treatment catalyst is 50-90%.

8. The method according to claim 7, wherein, In step S3, along the flow direction of the distillate oil, the hydroprotection catalyst sequentially includes catalyst A, catalyst B and catalyst C; Based on the total volume of the hydrogenation protection catalyst, the content of catalyst A is 5-20%, the content of catalyst B is 10-50%, and the content of catalyst C is 30-85%. The catalyst A contains a first hydrogenation active metal and a first support; the first hydrogenation active metal includes Group VB metals and Group VIB metals, and the first support is selected from alumina and / or silicon oxide; based on the total weight of the catalyst A and calculated as oxides, the content of the Group VB metal is less than 12% by weight, and the content of the Group VIB metal is 0.2-12% by weight; the first support contains phosphorus and halogens, based on the total weight of the first support, the phosphorus content is 0.1-8.0% by weight (calculated as P2O5), and the halogen content is 0.1-6% by weight (calculated as an element). The catalyst B contains a second hydrogenation active metal and a second support; the second hydrogenation active metal includes a Group VIB metal and optionally a Group VIII metal, and the second support is selected from alumina and / or silica; based on the total weight of the catalyst B and calculated as oxides, the content of the Group VIB metal is greater than 0 and less than 4% by weight, and the content of the Group VIII metal is 0-0.8% by weight; the second support contains phosphorus and halogens, based on the total weight of the second support, the phosphorus content is 0.1-8.0% by weight (calculated as P2O5), and the halogen content is 0.1-6% by weight (calculated as an element). The catalyst C contains a third hydrogenation active metal and a third support; the third hydrogenation active metal includes Group VIII metals and Group VIB metals, and the third support is selected from alumina and / or silica; based on the total weight of the catalyst C and calculated as oxides, the content of the Group VIB metal is 0.2-10% by weight, and the content of the Group VIII metal is less than 5% by weight; the third support contains phosphorus, and based on the total weight of the third support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight. Preferably, the volume ratio of catalyst A, catalyst B and catalyst C is 1:(1-10):(1.5-17), more preferably 1:(2-5):(3-15).

9. The method according to claim 7, wherein, In step S3, along the flow direction of the distillate oil, the hydrotreating catalyst sequentially includes catalyst I and catalyst II; The catalyst I comprises a hydrogenation catalyst Ia, which contains a first promoter, a fourth hydrogenation active metal component, and a fourth support. The first promoter comprises one or more of fluorine, boron, and phosphorus; the metal element in the fourth hydrogenation active metal component comprises one or more of Co, Mo, Ni, and W; the fourth support is selected from alumina and / or silicon oxide; based on the dry weight of the hydrogenation catalyst Ia, the content of the fourth hydrogenation active metal component, calculated as metal oxide, is 16-45% by weight, and the content of the first promoter is 0.5-10% by weight. Preferably, the catalyst I further includes a hydrogenation catalyst Ib disposed upstream of the hydrogenation catalyst Ia; the hydrogenation catalyst Ib contains a fifth hydrogenation active metal component and a fifth support, and the content of the fifth hydrogenation active metal component is 2-15% by weight based on the dry weight of the hydrogenation catalyst Ib; the fifth hydrogenation active metal component is selected from one or more of Co, Mo, Ni and W; the fifth support is selected from alumina and / or silicon oxide; Preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (3-10):

1.

10. The method according to claim 9, wherein, In step S3, the second hydrogenation catalyst further includes catalyst II disposed downstream of catalyst I; The catalyst II contains a second promoter, a sixth hydrogenation active metal component, and a sixth support. The second promoter includes boron and / or phosphorus. The content of the sixth hydrogenation active metal component, based on the dry weight of the catalyst II and calculated as metal oxide, is 16-52% by weight. The sixth hydrogenation active metal component is selected from one or more of Co, Mo, Ni, and W. The sixth support is selected from alumina and / or silicon oxide. The catalyst II is a fluorine-free hydrogenation catalyst, and the content of the second promoter is 2-8% by weight. The content of the sixth hydrogenation active metal component of the catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components of the catalyst I. Preferably, the volume ratio of catalyst I to catalyst II is (30:70)-(60:40).

11. The method according to claim 7, wherein, In step S3, the conditions for the high-pressure hydrogenation reaction in which the distillate oil contacts the hydrotreating protective catalyst include: a hydrogen partial pressure of 3-20 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature is 260-380℃, and the volume hourly space velocity is 0.2-5h. -1 ; Preferably, the hydrogen partial pressure is 5-12 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3h. -1 .

12. The method according to claim 7, wherein, In step S3, the conditions for the high-pressure hydrogenation reaction between the distillate oil and the hydrotreating catalyst include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000 Nm³. 3 / m 3 The reaction temperature of catalyst I is 260-420℃, and the volume hourly space velocity is 0.2-3 h⁻¹. -1 The reaction temperature of catalyst II is 240-380℃, and the volume hourly space velocity is 0.2-3h. -1 ; Preferably, the hydrogen partial pressure is 5-20 MPa, and the hydrogen-to-oil volume ratio is 300-1800 Nm. 3 / m 3 The reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2h. -1 The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

13. A system for hydrogenating and regenerating waste lubricating oil using any one of claims 1-12, the system comprising: Slurry bed, fractionation tower, solid-liquid separation unit and high-pressure fixed bed hydrogenation unit; The product outlet of the slurry bed is in fluid communication with the inlet of the fractionation tower, the residue outlet of the fractionation tower is in fluid communication with the inlet of the solid-liquid separation device, the liquid outlet of the solid-liquid separation device is in flow communication with the inlet of the slurry bed, and the distillate oil outlet of the fractionation tower is in fluid communication with the inlet of the high-pressure fixed-bed hydrogenation device.

14. The system according to claim 13, wherein, Along the flow direction of the material to be processed, the high-pressure fixed-bed hydrogenation device includes a hydrogenation protection reaction zone and a hydrogenation treatment reaction zone.

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