A method and system for hydroregenerating spent lubricating oil

Abstract

The present application relates to a kind of waste lubricating oil hydroregeneration method and system, the method comprises: S1, waste lubricating oil is contacted with oil-soluble catalyst in slurry bed and is carried out hydrogenation pretreatment, obtains hydrogenation mixture;S2, hydrogenation mixture is carried out flash evaporation, obtains gas phase component and the liquid phase component containing catalyst;S3, at least part of the liquid phase component containing catalyst is carried out solid-liquid separation, obtains metal tailings and lubricating oil base oil fraction;S4, lubricating oil base oil fraction is contacted with first hydrogenation catalyst and carries out medium-pressure hydrogenation reaction, obtains medium-pressure hydrogenation product;S5, medium-pressure hydrogenation product is carried out fractionation, obtains gas, light lubricating oil fraction and heavy lubricating oil fraction;S6, light lubricating oil fraction and heavy lubricating oil base oil fraction are contacted with second hydrogenation catalyst respectively and carry out high-pressure hydrogenation reaction.The method of the present application has high lubricating oil base oil recovery rate and good quality.

Description

Technical Field

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

[0004] CN101041789A discloses a method for hydrogenating and regenerating waste lubricating oil. This method includes the following steps: the raw waste lubricating oil is subjected to dehydration, filtration, and adsorption treatment to remove water, mechanical impurities, gums, asphaltenes, and most heavy metal impurities; the adsorbed waste lubricating oil is further purified by pre-hydrogenation in a reactor containing a protective agent to remove impurities; the pre-hydrogenated waste lubricating oil enters the main hydrogenation reactor, where hydrogenation is achieved under the action of a hydrogenation catalyst, saturating the non-ideal components in the raw oil with hydrogen, and the product is fractionated. This method only removes some mechanical impurities through physical methods and hydrogenation protective agents, resulting in limited removal of gums and asphaltenes from the heavy fraction of the waste lubricating oil, and the operating cycle cannot be guaranteed. Furthermore, due to the mixed sources of the waste lubricating oil, hydrogenation alone results in low product quality and is heavily dependent on the quality of the raw materials. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for hydrogenating and regenerating waste lubricating oil. The method disclosed herein can effectively remove metal and non-metal heteroatoms from waste lubricating oil and saturate some polycyclic aromatic hydrocarbons, thereby reducing the severity of subsequent processing and resulting in high recovery rate and good quality of 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. The waste lubricating oil is contacted with the oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0008] S2. The hydrogenated mixture is flash-evaporated to obtain a gaseous component and a liquid component containing a catalyst;

[0009] S3. At least a portion of the catalyst-containing liquid phase component is subjected to solid-liquid separation to obtain a fraction containing metal tailings and lubricating oil base oil.

[0010] S4. In a medium-pressure fixed-bed hydrogenation unit, the lubricating oil base oil fraction is brought into contact with the first hydrogenation catalyst to carry out a medium-pressure hydrogenation reaction to obtain a medium-pressure hydrogenation product.

[0011] S5. The medium-pressure hydrogenation product is fractionated to obtain gas, light lubricating oil fraction and heavy lubricating oil fraction;

[0012] S6. In the high-pressure fixed-bed hydrogenation unit, the light lubricating oil fraction and the heavy lubricating oil base oil fraction are respectively contacted with the second hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0013] 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 .

[0014] Optionally, in step S1, the oil-soluble catalyst includes a catalyst main agent and an auxiliary agent; the molar ratio of the catalyst main agent (calculated as metal element) to the auxiliary agent (calculated as sulfur element) in the oil-soluble catalyst is 1:(0.5-5), preferably 1:(0.5-4);

[0015] The additive includes sulfur-containing substances; preferably, the sulfur-containing compound includes one or more of carbon disulfide, sulfur, dimethyl disulfide and di-tert-butyl polysulfide.

[0016] The catalyst host comprises a metal central atom or central ion, and an organic ligand coordinated with the metal central atom or central ion; the general formula of the catalyst host is: MO a [R(COOH b ) x ] c ,

[0017] Where M represents a metal, R(COOH) b ) x The organic ligand represents the organic ligand comprising a carboxyl group and a carboxylic acid group; R represents the hydrocarbon group in the organic ligand; x represents the molar ratio of the total number of the carboxyl group and the carboxylic acid group to the hydrocarbon group R; a represents the molar ratio of the noncoordinate bonded oxygen atom connected to the metal M to the metal M; b represents the molar ratio of the carboxylic acid group to the total number of the carboxyl group and the carboxylic acid group; and c represents the molar ratio of the organic ligand to the metal M, wherein:

[0018] The metal is a Group B and / or Group VIII metal with hydrogenation properties;

[0019] x is 1, 2 or 3, preferably 1 or 2;

[0020] a is a positive number from 0 to 5, preferably a positive number from 1 to 3;

[0021] b is a positive number between 0.01 and 0.99, preferably a positive number between 0.1 and 0.5;

[0022] c is a positive number between 0.5 and 10, preferably a positive number between 1 and 5.

[0023] Optionally, in step S1, based on the dry weight of the catalyst main agent, the metal content in the catalyst main agent is 2-40% by weight, preferably 2-35%, preferably 8-30%, and more preferably 10-20%.

[0024] The metal is one or more of Ti, V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Zn, preferably one or more of V, Mo, W, Fe, Co, Ni, Cu and Zn, and more preferably one or more of Mo, W, Ni, Co and Fe;

[0025] R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal or isomeric alkyl group, a C5-C12 cycloalkyl group, or a C6-C12 aryl group.

[0026] Optionally, in step S1, the amount of the oil-soluble catalyst, calculated as metal element, relative to 1g of the waste lubricating oil is 20-10000μg, preferably 50-5000μg, and more preferably 100-3000μg.

[0027] Optionally, in step S2, the flash evaporation conditions include: the flash evaporation pressure is lower than the reaction pressure of the slurry bed, preferably 2-25 MPa, and the gasification rate is 3-25% by weight; the distillation range of the catalyst-containing tail oil is 200-600°C.

[0028] Optionally, step S3 includes: introducing a portion of the catalyst-containing liquid phase component into the slurry bed, and performing solid-liquid separation on the remaining portion of the catalyst-containing liquid phase component;

[0029] Preferably, the amount of the catalyst-containing liquid phase component introduced into the slurry bed is 0-70% by weight of the total amount of the catalyst-containing liquid phase component obtained in step S2, and more preferably 0-60% by weight.

[0030] Optionally, in step S4, the conditions for the medium-pressure hydrogenation reaction include: a hydrogen partial pressure of 3-20 MPa, a hydrogen-to-oil volume ratio of 200-3000, a reaction temperature of 260-380°C, and a volume hourly space velocity of 0.2-5 h⁻¹. -1 ;

[0031] Preferably, the hydrogen partial pressure is 5-12 MPa, the hydrogen-to-oil volume ratio is 300-1800, the reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3 h⁻¹. -1 .

[0032] Optionally, in step S4, along the flow direction of the lubricating oil base oil fraction, the first hydrogenation catalyst includes catalyst A, catalyst B and catalyst C arranged sequentially; by volume and based on the total volume of the first hydrogenation catalyst, the content of catalyst A in the first hydrogenation catalyst is 5-20%, the content of catalyst B is 10-50%, and the content of catalyst C is 30-85%.

[0033] 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. 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).

[0034] 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).

[0035] 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.

[0036] 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).

[0037] Optionally, in step S5, the fractionation conditions include: a pressure of -90 kPa to -99 kPa and a bottom temperature of 300-400°C, preferably 320-370°C;

[0038] The distillation range of the light lubricating oil fraction is 280-520℃, preferably 300-500℃;

[0039] The distillation range of the heavy lubricating oil fraction is above 500°C, preferably above 520°C.

[0040] Optionally, in step S6, along the flow direction of the light lubricating oil fraction and the heavy lubricating oil base oil fraction, the second hydrogenation catalyst includes catalyst I and catalyst II arranged sequentially;

[0041] 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.

[0042] 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;

[0043] Preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is 10:1 to 3:1.

[0044] Optionally, in step S6, the second hydrogenation catalyst further includes a hydrogenation catalyst II disposed downstream of the hydrogenation catalyst I;

[0045] The hydrogenation 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 hydrogenation 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 hydrogenation catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components of the hydrogenation catalyst I.

[0046] Preferably, the volume ratio of the hydrogenation catalyst I to the hydrogenation catalyst II is (30:70)-(60:40).

[0047] Optionally, in step S6, the conditions for the high-pressure hydrogenation reaction include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000; wherein the reaction temperature of catalyst I is 260-420°C 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 ;

[0048] Preferably, the hydrogen partial pressure is 5-20 MPa, and the hydrogen-to-oil volume ratio is 300-1800; wherein the reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2 h⁻¹. -1 The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

[0049] The second aspect of this disclosure provides a system for the hydrogenation regeneration of waste lubricating oil using the method provided in the first aspect of this disclosure. The system includes: a slurry bed, a flash distillation tower, a solid-liquid separation device, a fractionation tower, a medium-pressure fixed-bed hydrogenation device, and a high-pressure fixed-bed hydrogenation device.

[0050] The product outlet of the slurry bed is fluidly connected to the inlet of the flash tower; the liquid outlet of the flash tower is fluidly connected to the inlet of the solid-liquid separation device, and optionally to the inlet of the slurry bed; the liquid outlet of the solid-liquid separation device is fluidly connected to the inlet of the medium-pressure fixed-bed hydrogenation device, the outlet of the medium-pressure fixed-bed hydrogenation device is fluidly connected to the inlet of the fractionation tower, and the outlets of the light lubricating oil fraction and the heavy lubricating oil base oil fraction of the fractionation tower are each independently fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

[0051] The advantages of the present invention through the above technical solution are as follows:

[0052] (1) This disclosure employs a slurry bed for hydrogenation pretreatment of 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, during the slurry bed hydrogenation pretreatment process, more than 50% by weight of the fraction with a boiling point greater than 520°C in the entire fraction of waste lubricating oil can be converted into lubricating oil base oil fraction, and the conversion rate of the fraction with a boiling range of 280-520°C is not higher than 10%, resulting in a high yield of lubricating oil base oil fraction obtained from the regeneration process.

[0053] (2) The oil-soluble catalyst used in the hydrogen pretreatment of this disclosure can be better and more uniformly dispersed in waste lubricating oil, and can better contact the reaction, thereby improving the reaction effect and liquid phase product yield of catalytic hydrogen pretreatment.

[0054] (3) This disclosure involves fixed-bed hydrogenation of light lubricating oil fraction and heavy lubricating oil base oil fraction, which ensures long-term operation of the catalyst and improves product quality.

[0055] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0056] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0057] Figure 1 This is a flowchart illustrating a specific embodiment of the waste lubricating oil hydrogenation regeneration method disclosed herein. Detailed Implementation

[0058] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0059] A first aspect of the present invention provides a method for hydrogenating and regenerating waste lubricating oil, the method comprising:

[0060] S1. The waste lubricating oil is contacted with the oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0061] S2. The hydrogenated mixture is flash-evaporated to obtain a gaseous component and a liquid component containing a catalyst;

[0062] S3. At least a portion of the catalyst-containing liquid phase component is subjected to solid-liquid separation to obtain a fraction containing metal tailings and lubricating oil base oil.

[0063] S4. In a medium-pressure fixed-bed hydrogenation unit, the lubricating oil base oil fraction is brought into contact with the first hydrogenation catalyst to carry out a medium-pressure hydrogenation reaction to obtain a medium-pressure hydrogenation product.

[0064] S5. The medium-pressure hydrogenation product is fractionated to obtain gas, light lubricating oil fraction and heavy lubricating oil fraction;

[0065] S6. In the high-pressure fixed-bed hydrogenation unit, the light lubricating oil fraction and the heavy lubricating oil base oil fraction are respectively contacted with the second hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0066] This disclosed method employs a slurry bed for hydrogenation pretreatment of the entire fraction of waste lubricating oil, effectively removing metal and non-metal heteroatoms and saturating some polycyclic aromatic hydrocarbons, thus reducing the severity of subsequent processing. Simultaneously, the use of an oil-soluble catalyst facilitates better and more uniform dispersion of the catalyst in the waste oil, allowing for more thorough contact and reaction, thereby improving the reaction efficiency of the catalytic hydropyrolysis reaction and the yield of liquid-phase products. This disclosure separately hydrogenates the light lubricating oil fraction and the heavy lubricating oil base oil fraction in a fixed bed, ensuring long-term catalyst operation and improved product quality, resulting in high recovery rate and high quality of the lubricating oil base oil.

[0067] 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 is 100-3000 Nm³. 3 / m 3 Preferably, the reaction temperature is 350-450℃; the reaction pressure is 3-20MPa; and the liquid hourly space velocity is 0.25-3h. -1 The volume ratio of hydrogen to the waste lubricating oil is 200-3000 Nm³. 3 / m 3 .

[0068] In one specific embodiment of this disclosure, in step S1, the oil-soluble catalyst comprises a catalyst main agent and an auxiliary agent; the molar ratio of the catalyst main agent (calculated as metal element) to the auxiliary agent (calculated as sulfur element) in the oil-soluble catalyst can vary within a wide range, for example, it can be 1:(0.5-5), preferably 1:(0.5-4); the catalyst main agent contains a metal central atom or central ion, and an organic ligand coordinated with the metal central atom or central ion; the general formula of the catalyst main agent is: MO a [R(COOH b ) x ] c Where M represents a metal, R(COOH)b ) x The organic ligand represents the organic ligand, which includes a carboxyl group and a carboxylic acid group. R represents the hydrocarbon group in the organic ligand. x represents the molar ratio of the total number of the carboxyl group and the carboxylic acid group to the hydrocarbon group R. a represents the molar ratio of the non-coordinate bonded oxygen atom connected to the metal M to the metal M. b represents the molar ratio of the carboxylic acid group to the total number of the carboxyl group and the carboxylic acid group. c represents the molar ratio of the organic ligand to the metal M. The metal is a Group B and / or Group VIII metal with hydrogenation properties; x is 1, 2, or 3, preferably 1 or 2; a is a positive number from 0 to 5, preferably a positive number from 1 to 3; b is a positive number from 0.01 to 0.99, preferably a positive number from 0.1 to 0.5; c is a positive number from 0.5 to 10, preferably a positive number from 1 to 5. In this embodiment, the hydrogenation catalyst main agent has high hydrogenation activity. When used for oil hydrogenation, the coordinating groups of the organic ligands in the hydrogenation catalyst main agent form coordination bonds with the metal central atom or central ion through oxygen atoms. It can be efficiently dispersed in the oil phase and has high hydrogenation activity during the reaction process. It can obtain a high feedstock cracking rate and a heteroatom removal rate, and can maintain a low condensation rate, ultimately achieving the lightening and upgrading of oil feedstock.

[0069] In one specific embodiment of this disclosure, based on the dry weight of the catalyst main agent, the content of the metal in the catalyst main agent is 2-40% by weight, preferably 2-35%, more preferably 8-30%, and even more preferably 10-20%; the metal is one or more of Ti, V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu, and Zn, preferably one or more of V, Mo, W, Fe, Co, Ni, Cu, and Zn, and even more preferably one or more of Fe, Ni, Mo, and Zn; R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal or isomeric alkyl group, a C5-C12 cycloalkyl group, and a C6-C12 aryl group.

[0070] In this disclosure, "C3-C19 hydrocarbon group" refers to a hydrocarbon group having 3-19 carbon atoms. The hydrocarbon group can be a saturated or unsaturated straight-chain, branched, or carbocyclic hydrocarbon group, including but not limited to C3-C19 n-alkyl, C3-C19 isoalkyl, C5-C19 cycloalkyl, and C6-C19 aryl. "C5-C11 n-alkyl" refers to a straight-chain alkyl group having 5-11 carbon atoms, such as n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and n-undecyl. "C5-C11 isoalkyl" refers to a branched alkyl group having 5-11 carbon atoms, such as isopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, and isoundecyl. "C5-C12 cycloalkyl" refers to a saturated hydrocarbon group containing a saturated carbon ring with 5-12 carbon atoms, such as cyclopentyl, cyclohexyl, methylcyclohexyl, decahydronaphthyl, methyldecahydronaphthyl, ethyldecahydronaphthyl, etc. "C6-C12 aryl" refers to a group containing an aromatic ring with 6-12 carbon atoms, such as phenyl, naphthyl, anthraceneyl, p-tolyl, benzyl, methylnaphthyl, etc.

[0071] According to this disclosure, the C3-C19 hydrocarbon group, C5-C11 normal alkyl group, C5-C11 isoalkyl group, C5-C12 cycloalkyl group and C6-C12 aryl group may be optionally substituted, for example, they may be unsubstituted, or they may be substituted by one or more groups selected from halogen, nitro, sulfonic acid group and the like.

[0072] In one specific embodiment of this disclosure, the infrared spectrum of the catalyst main agent is at least in the range of 1350-1450 cm⁻¹. -1 and 1500-1610cm -1 It has a characteristic peak at the location.

[0073] According to this disclosure, the catalyst main agent can be highly dispersed in the oil phase, such as oil-soluble molybdenum catalyst, oil-soluble molybdenum-cobalt catalyst, oil-soluble molybdenum-nickel catalyst, oil-soluble iron-molybdenum catalyst, oil-soluble iron-zinc catalyst, etc. In a specific embodiment of this disclosure, the catalyst main agent can be an oil-soluble catalyst such as iron naphthenate or iron carboxylate.

[0074] According to this disclosure, the oil-soluble catalyst includes an additive; the additive includes sulfur-containing substances, which may include, but are not limited to, one or more of carbon disulfide, sulfur, dimethyl disulfide (DMDS), and di-tert-butyl polysulfides.

[0075] In one specific embodiment of this disclosure, in step S1, the amount of the oil-soluble catalyst, calculated as metal element, relative to 1g of the waste lubricating oil is 20-10000μg, preferably 50-5000μg, and more preferably 100-3000μg.

[0076] In one specific embodiment of this disclosure, in step S2, the flash evaporation conditions include: the flash evaporation pressure is lower than the reaction pressure of the slurry bed, preferably 2-25 MPa, and the gasification rate is 3-15% by weight; the distillation range of the catalyst-containing tail oil is 200-600°C.

[0077] In one specific embodiment of this disclosure, step S3 includes: introducing a portion of the catalyst-containing liquid phase component into the slurry bed, and performing solid-liquid separation on the remaining portion of the catalyst-containing liquid phase component. According to this disclosure, the amount of the catalyst-containing liquid phase component introduced into the slurry bed can vary within a wide range relative to the total amount of the catalyst-containing liquid phase component. In one specific embodiment of this disclosure, the amount of catalyst-containing tail oil introduced into the slurry bed accounts for 0-70% by weight of the total amount of catalyst-containing tail oil, preferably 0-60% by weight. In this embodiment, recycling a portion of the catalyst-containing tail oil back into the slurry bed can improve the utilization rate of the oil-soluble catalyst. The lubricating oil base oil fraction accounts for more than 95% by weight of the catalyst-containing tail oil; the total metal content of the lubricating oil base oil fraction is not greater than 10 μg / g, and the content of n-heptane insoluble matter is not greater than 100 μg / g.

[0078] 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. In one specific embodiment of this disclosure, the solid-liquid separation is performed using solvent extraction separation, where the remaining portion of the catalyst-containing liquid phase component 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 the remaining portion of the catalyst-containing liquid phase component is 1-10 parts by weight, preferably 1-5 parts by weight. The extractant can be well known to those skilled in the art, for example, at least one of C3-C8 alkanes, C3-C8 olefins, toluene, and light naphtha, preferably selected from C3-C5 alkanes and / or toluene.

[0079] In one specific embodiment of this disclosure, the conditions for the medium-pressure hydrogenation reaction in step S4 include: a hydrogen partial pressure of 3-20 MPa, a hydrogen-to-oil volume ratio of 200-3000, a reaction temperature of 260-380°C, and a volume hourly space velocity of 0.2-5 h⁻¹. -1 Preferably, the hydrogen partial pressure is 5-12 MPa, the hydrogen-to-oil volume ratio is 300-1800, the reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3 h⁻¹. -1 .

[0080] In one specific embodiment of this disclosure, in step S4, along the flow direction of the lubricating oil base oil fraction, the first hydrogenation catalyst includes catalyst A, catalyst B, and catalyst C arranged sequentially; by volume and based on the total volume of the first hydrogenation catalyst, the content of catalyst A in the first hydrogenation catalyst is 5-20%, the content of catalyst B is 10-50%, and the content of catalyst C is 30-85%; the catalyst support is characterized by mercury porosimetry, the first pore distribution of the support is mesopores located at 3-100 nm, with a pore volume Vmesopores of 1.0-1.5 mL / g, the second pore distribution is macropores located at 100-5000 nm, with a pore volume Vmacropores of 1.0-1.8 mL / g, and the total pore volume Vtotal is 2.0-3.3 mL / g;

[0081] 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, 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, and the halogen content calculated as elements is 0.1-6% by weight.

[0082] 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 2-6% by weight, and the halogen content calculated as an element is 0.1-6% by weight, preferably 0.1-4.5% by weight.

[0083] 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 2-6% by weight.

[0084] In one specific embodiment of this disclosure, the volume ratio of the catalyst A, the catalyst B and the catalyst C is 1:(1-10):(1.5-17), preferably 1:(2-5):(3-15).

[0085] In one specific embodiment of this disclosure, in step S5, the conditions for fractionation include: a pressure of -90 kPa to -99 kPa, a bottom temperature of 300-400°C, preferably 320-370°C; a distillation range of 280-520°C for the light lubricating oil fraction, preferably 300-500°C; and a distillation range of over 500°C for the heavy lubricating oil base oil fraction, preferably greater than 520°C.

[0086] 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 S6, along the flow direction of the light lubricating oil fraction and the heavy lubricating oil base oil fraction, the second hydrogenation catalyst includes catalyst I and catalyst II arranged sequentially.

[0087] In one specific embodiment of this disclosure, catalyst I comprises 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 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.

[0088] 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 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 10:1-3:1. The above-described gradation scheme of the hydrogenation protection catalyst and the hydrogenation treatment catalyst in this disclosure extends the operating cycle of the unit, increases the depth of hydrorefining, and improves the quality of the base oil.

[0089] 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.

[0090] According to a preferred embodiment, the hydrogenation 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 the hydrogenation 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. The 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 of the hydrogenation catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components of the hydrogenation catalyst I. Preferably, the volume ratio of the hydrogenation catalyst I to the hydrogenation catalyst II is (30:70)-(60:40).

[0091] The method disclosed herein employs a high-performance first and second hydrogenation catalyst and uses a novel catalyst gradation scheme, which can prevent the pressure drop of the fixed-bed hydrogenation reactor from rising rapidly, extend the operating cycle of the unit, and improve product quality.

[0092] In one specific embodiment of this disclosure, in step S6, the conditions for the high-pressure hydrogenation reaction include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000; wherein the reaction temperature of catalyst I is 260-420°C and the volume hourly space velocity is 0.2-3 h⁻¹. -1The 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; wherein the reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2 h⁻¹. -1 The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

[0093] In this disclosure, the reaction pressure of the medium-pressure hydrogenation reaction is lower than that of the high-pressure hydrogenation reaction.

[0094] This disclosure provides a system for the hydrogenation regeneration of waste lubricating oil using the method provided in the first aspect of this disclosure. The system includes: a slurry bed, a flash distillation tower, a solid-liquid separation device, a fractionation tower, a medium-pressure fixed-bed hydrogenation device, and a high-pressure fixed-bed hydrogenation device. The product outlet of the slurry bed is fluidly connected to the inlet of the flash distillation tower. The liquid outlet of the flash distillation tower is fluidly connected to the inlet of the solid-liquid separation device, and optionally to the inlet of the slurry bed. The liquid outlet of the solid-liquid separation device is fluidly connected to the inlet of the medium-pressure fixed-bed hydrogenation device, and the outlet of the medium-pressure fixed-bed hydrogenation device is fluidly connected to the inlet of the fractionation tower. The light lubricating oil fraction outlet and the heavy lubricating oil base oil fraction outlet of the fractionation tower are each independently fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

[0095] The present invention will be further described in detail below through examples.

[0096] 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.

[0097] Table 1 Properties of waste lubricating oil

[0098]

[0099]

[0100] The preparation methods and reaction raw materials of the oil-soluble catalyst main agent used in Examples 1-10 are shown in Table 2. The specific method is as follows: Weigh the corresponding weight of the compound as shown in Table 2, place it in a three-necked flask, and then carry out the reaction under the conditions shown in Table 2. Separate the gas generated during the reaction. After the reaction is completed, the metal compound in the flask is completely dissolved. Pour out the liquid reaction product in the flask and place it in a separatory funnel for oil-water separation. Let it stand for 2 hours, and separate the liquid to obtain the upper oil phase product, which is the catalyst main agent of the oil-soluble catalyst.

[0101] Table 2

[0102]

[0103] Example 1

[0104] S1. Waste lubricating oil is contacted with an oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenation mixture; wherein the oil-soluble catalyst contains a main agent and an auxiliary agent.

[0105] S2. Flash evaporate the hydrogenated mixture to obtain a gaseous component and a liquid component containing the catalyst;

[0106] S3. Introduce a portion of the catalyst-containing liquid phase component into a slurry bed; perform solid-liquid separation on the remaining catalyst-containing liquid phase component to obtain a fraction containing metal tailings and lubricating oil base oil.

[0107] S4. In the medium-pressure fixed-bed hydrogenation unit, the lubricating oil base oil fraction is brought into contact with the first hydrogenation catalyst to carry out a medium-pressure hydrogenation reaction to obtain the medium-pressure hydrogenation product.

[0108] S5. The medium-pressure hydrogenation product is fractionated to obtain gas, light lubricating oil fraction and heavy lubricating oil fraction;

[0109] S6. In the high-pressure fixed-bed hydrogenation unit, the light lubricating oil fraction and the heavy lubricating oil base oil fraction are respectively contacted with the second hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0110] The reaction conditions, product results, and product property analysis results of the above steps are shown in Tables 4 and 5.

[0111] Along the flow direction of the lubricating oil base oil fraction, the first hydrogenation catalyst includes catalyst A, catalyst B and catalyst C arranged in sequence, and the composition of the catalyst is shown in Table 3.

[0112] Catalyst A contains 8.0 wt% WO3, 1.6 wt% V2O5 and the balance support. Based on the total weight of the support, the phosphorus content is 1.8 wt% as P2O5 and the halogen fluorine content is 1.0 wt% as elemental.

[0113] The following method was used to prepare the aluminum sulfate solution: 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 that the hydrated alumina precipitate had an amorphous structure). 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 make the pH of the slurry 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 pseudoboehmite 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 (product of Tianjin Chemical Reagent Factory No. 3) and 9.8g of ammonium fluoride. The solution was extruded into a butterfly strip with an outer diameter of φ1.4mm on a twin-screw extruder. The wet strip was dried at 120°C for 4 hours to obtain a molded article. The molded article was calcined at 600°C for 3 hours to obtain a carrier. 200 g of Z3 was impregnated with 220 mL of a mixed solution of ammonium tungstate and ammonium vanadate containing 80 g / L WO3 and 16 g / L V2O5 for 1 hour, dried at 120°C for 4 hours, and calcined at 400°C for 3 hours to obtain catalyst A.

[0114] Catalyst B contains 3.0 wt% MoO3, 0.5 wt% NiO, and the balance is a support. Based on the dry weight of the support, the phosphorus content (P2O5) is 4.9 wt%, and the halogen fluorine content (elemental) is 1.0 wt%.

[0115] The preparation method is as follows: Prepare 2 L of aluminum sulfate solution with an Al2O3 concentration of 50 g / L, add 5 mL of concentrated phosphoric acid (85% by weight) and 9.5 g of boric acid to obtain an aluminum sulfate solution containing phosphorus and boron. Add the above aluminum sulfate solution and an 8% ammonia solution in a 5 L reaction vessel in parallel flow to allow precipitation. After filtration (XRD characterization shows the hydrated alumina precipitate to be an amorphous structure), the reaction temperature is 40 °C, and the flow rate of the ammonia solution is controlled to maintain the pH of the reaction system at 5.5. In a 5-liter reaction vessel, filter cake, deionized water, and ammonia were mixed and slurried. The amount of ammonia was adjusted to a pH of 8.0. The slurry was aged at 65°C for 60 minutes and then filtered. The filter cake was washed twice with deionized water and dried at 120°C for 24 hours to obtain hydrated alumina P1. P1 was calcined at 600°C for 4 hours to obtain alumina Z1. XRD characterization showed that P1 had a boehmite-like structure, and A1 had a γ-alumina structure. 1000g of the prepared hydrated alumina P1 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 solution 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℃ for 4 hours to obtain the molded article, and the molded article is calcined at 600℃ for 3 hours to obtain the carrier Z1.

[0116] Take 200 g of support Z1, impregnate it with 220 mL of a mixed solution of ammonium heptamolybdate and nickel nitrate containing 28.8 g / L MoO3 and 5 g / L NiO for 1 hour, dry it at 120 °C for 4 hours, and calcine it at 400 °C for 3 hours to obtain catalyst B.

[0117] Catalyst C contains 8.0 wt% MoO3, 1.6 wt% CoO and the balance support, with the support containing 4.9 wt% phosphorus as P2O5.

[0118] The catalyst was prepared as follows: 1000 g of the hydrated alumina P1 prepared above was weighed and added to 1440 ml of an aqueous solution containing 10 ml of nitric acid (a product of Tianjin Chemical Reagent Factory No. 3). The solution was extruded into a butterfly-shaped strip with an outer diameter of φ1.4 mm on a twin-screw extruder. The wet strip was dried at 120°C for 4 hours to obtain a molded product. The molded product was calcined at 700°C for 3 hours to obtain a support Z7. 200 g of support Z7 was impregnated with 220 ml of a mixed solution of ammonium heptamolybdate and nickel nitrate containing 80 g / L MoO3 and 16 g / L CoO for 1 hour, dried at 120°C for 4 hours, and calcined at 400°C for 3 hours to obtain catalyst C.

[0119] Table 3 Composition of catalysts A, B, and C

[0120]

[0121] Along the flow direction of the light lubricating oil fraction and the heavy lubricating oil base oil fraction, the second hydrogenation catalyst includes hydrogenation catalyst Ib, hydrogenation catalyst Ia and catalyst II arranged in sequence, and the composition of the catalyst is shown in Table 4.

[0122] The hydrogenation catalyst Ia contains 2.4 wt% NiO, 2.1 wt% MoO3, 21 wt% WO3, 0.8 wt% P2O5 and the balance silica-alumina support.

[0123] The solution was prepared by dissolving 3127g of Al2(SO4)3·18H2O (analytical grade, [Al2(SO4)3·18H2O] content ≥99.0 wt%, water-insoluble matter ≤0.02 wt%, chloride (Cl) ≤0.002 wt%, iron (Fe) ≤0.003 wt%, the same below) and 845g of 98% sulfuric acid (concentration 98 wt%, analytical grade, the same below) in 4968g of deionized water to prepare solution I (pH value 0.34, Al2O3 content 85 g / L). 2070g of sodium silicate solution (analytical grade, molecular formula: Na2SiO3·9H2O, content (as Na2O): 19.3-22.8 wt%, iron ≤0.02 wt%, heavy metals (as Pb) ≤0.001 wt%, the same below) was diluted with water to prepare solution II (containing 40 g / L SiO2, pH value 13.58). Under vigorous stirring, solution II and 1.75g ​​of ferrous sulfate (analytical grade, Beijing Yili Fine Chemicals Co., Ltd., the same below) were added to solution I to prepare a transparent silicon-aluminum mixed solution III. The pH of silicon-aluminum mixed solution III was 3.1, and the SiO2 / Al2O3 mass ratio was 3.0. Dilute ammonia water (containing 5 wt% NH3) was mixed with the above silicon-aluminum solution III at a stirring speed of 3000 RPM, wherein the ammonia water was added at a rate that adjusted the pH of the mixture to within the range of 8.0 ± 0.3.

[0124] 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-1 of the silicon-aluminum composite material carrier was obtained. Based on the weight of the added ferrous sulfate and the obtained precursor SAS-1, the iron content in the precursor of the silicon-aluminum composite material carrier, calculated as Fe2O3, was 0.09% by weight.

[0125] 1000 grams of the precursor of the silicon-aluminum composite material carrier SAS-1 obtained in Example 1 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.

[0126] 3.12 g of concentrated phosphoric acid (85% by weight, analytical grade, Beijing Chemical Plant, hereinafter the same) and 40 mL of deionized water were heated to 75 °C, then mixed with 2.76 g of basic nickel carbonate (industrial grade, from Changling Catalyst Plant, hereinafter the same) and 5.73 g of molybdenum trioxide (industrial grade, from Changling Catalyst Plant, hereinafter the same), and the mixture was heated and stirred until dissolved. The solution was clear and transparent, and cooled to room temperature to obtain solution I. 62.96 g of ammonium metatungstate (industrial grade, Sichuan Zigong Hard Alloy Plant, hereinafter the same) and 20.68 g of nickel nitrate (analytical grade, Beijing Shuanghuan Chemical Reagent Plant, hereinafter the same) were added to 80 mL of deionized water and stirred until dissolved to obtain solution II. Solutions I and II were mixed at room temperature and adjusted to 160 mL with deionized water to obtain solution III. 200 g of the above support strip was impregnated with solution III for 1 hour, then removed and dried at 120 °C for 4 hours, and then calcined in air at 450 °C for 4 hours to obtain hydrogenation catalyst Ia.

[0127] 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.

[0128] Catalyst II contains 6.7 wt% NiO, 32.0 wt% WO3, 6.2 wt% MoO3, 5.9 wt% P2O5 and the balance support.

[0129] Example 2-10

[0130] Waste lubricating oil was treated using the same method as in Example 1, except that the reaction conditions were different, as shown in Tables 4 and 5.

[0131] Comparative Example 1

[0132] 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.

[0133] Table 4

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] In the table, the amount of oil-soluble catalyst (μg / g) refers to the amount of oil-soluble catalyst, calculated as metal element, relative to 1g of the waste lubricating oil.

[0140] 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 below.

[0141] Table 5

[0142]

[0143] In the table, the data corresponding to the hydrogen pretreatment yield of the 150N base oil fraction in Comparative Example 1 actually refers to the distillation pretreatment yield of the 150N base oil fraction.

[0144] Total base oil yield = (150N base oil fraction hydropretreatment yield × 150N base oil high-pressure hydrotreating yield + 120BS base oil fraction hydropretreatment yield × 120BS base oil high-pressure hydrotreating yield) × medium-pressure hydrotreating yield, where the medium-pressure hydrotreating yield in Comparative Example 1 is considered as 100%.

[0145] Table 6

[0146]

[0147]

[0148] Table 7

[0149]

[0150]

[0151] As can be seen from the above, the method disclosed herein yields lubricating oil base oil with high recovery rate and good quality.

[0152] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0153] 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, the present invention will not describe the various possible combinations separately.

[0154] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for hydrogenating and regenerating waste lubricating oil, the method comprising: S1. The waste lubricating oil is contacted with the oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture; S2. The hydrogenated mixture is flash-evaporated to obtain a gaseous component and a liquid component containing a catalyst; S3. At least a portion of the catalyst-containing liquid phase component is subjected to solid-liquid separation to obtain a fraction containing metal tailings and lubricating oil base oil. S4. In a medium-pressure fixed-bed hydrogenation unit, the lubricating oil base oil fraction is brought into contact with the first hydrogenation catalyst to carry out a medium-pressure hydrogenation reaction to obtain a medium-pressure hydrogenation product. S5. The medium-pressure hydrogenation product is fractionated to obtain gas, light lubricating oil fraction and heavy lubricating oil fraction; S6. In the high-pressure fixed-bed hydrogenation unit, the light lubricating oil fraction and the heavy lubricating oil base oil fraction are respectively contacted with the second hydrogenation catalyst to carry out 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 oil-soluble catalyst includes a catalyst main agent and an auxiliary agent; the molar ratio of the catalyst main agent (calculated as metal element) to the auxiliary agent (calculated as sulfur element) in the oil-soluble catalyst is 1:(0.5-5), preferably 1:(0.5-4); The additive includes sulfur-containing substances; preferably, the sulfur-containing compound includes one or more of carbon disulfide, sulfur, dimethyl disulfide and di-tert-butyl polysulfide. The catalyst host comprises a metal central atom or central ion, and an organic ligand coordinated with the metal central atom or central ion; the general formula of the catalyst host is: MO a [R(COOH b ) x ] c , Where M represents a metal, R(COOH) b ) x The organic ligand represents the organic ligand comprising a carboxyl group and a carboxylic acid group; R represents the hydrocarbon group in the organic ligand; x represents the molar ratio of the total number of the carboxyl group and the carboxylic acid group to the hydrocarbon group R; a represents the molar ratio of the noncoordinate bonded oxygen atom connected to the metal M to the metal M; b represents the molar ratio of the carboxylic acid group to the total number of the carboxyl group and the carboxylic acid group; and c represents the molar ratio of the organic ligand to the metal M, wherein: The metal is a Group B and / or Group VIII metal with hydrogenation properties; x is 1, 2 or 3, preferably 1 or 2; a is a positive number from 0 to 5, preferably a positive number from 1 to 3; b is a positive number between 0.01 and 0.99, preferably a positive number between 0.1 and 0.5; c is a positive number between 0.5 and 10, preferably a positive number between 1 and 5.

4. The method according to claim 3, wherein, In step S1, based on the dry weight of the catalyst main agent, the metal content in the catalyst main agent is 2-40% by weight, preferably 2-35%, preferably 8-30%, and more preferably 10-20%. The metal is one or more of Ti, V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Zn, preferably one or more of V, Mo, W, Fe, Co, Ni, Cu and Zn, and more preferably one or more of Mo, W, Ni, Co and Fe; R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal or isomeric alkyl group, a C5-C12 cycloalkyl group, or a C6-C12 aryl group.

5. The method according to claim 1, wherein, In step S1, the amount of the oil-soluble 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.

6. The method according to claim 1, wherein, In step S2, the flash evaporation conditions include: the flash evaporation pressure is lower than the reaction pressure of the slurry bed, preferably 2-25 MPa, and the gasification rate is 3-25% by weight; the distillation range of the catalyst-containing tail oil is 200-600℃.

7. The method according to claim 1, wherein, Step S3 includes: introducing a portion of the catalyst-containing liquid phase component into the slurry bed, and performing solid-liquid separation on the remaining portion of the catalyst-containing liquid phase component; Preferably, the amount of the catalyst-containing liquid phase component introduced into the slurry bed is 0-70% by weight of the total amount of the catalyst-containing liquid phase component obtained in step S2, and more preferably 0-60% by weight.

8. The method according to claim 1, wherein, In step S4, the conditions for the medium-pressure hydrogenation reaction include: a hydrogen partial pressure of 3-20 MPa, a hydrogen-to-oil volume ratio of 200-3000, a reaction temperature of 260-380°C, and a volume hourly space velocity of 0.2-5 h⁻¹. -1 ; Preferably, the hydrogen partial pressure is 5-12 MPa, the hydrogen-to-oil volume ratio is 300-1800, the reaction temperature is 280-360℃, and the volume hourly space velocity is 0.3-3 h⁻¹. -1 .

9. The method according to claim 1, wherein, In step S4, along the flow direction of the lubricating oil base oil fraction, the first hydrogenation catalyst includes catalyst A, catalyst B and catalyst C arranged sequentially; by volume and based on the total volume of the first hydrogenation catalyst, the content of catalyst A in the first hydrogenation catalyst 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. 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).

10. The method according to claim 1, wherein, In step S5, the fractionation conditions include: a pressure of -90 kPa to -99 kPa and a bottom temperature of 300-400°C, preferably 320-370°C. The distillation range of the light lubricating oil fraction is 280-520℃, preferably 300-500℃; The distillation range of the heavy lubricating oil fraction is above 500°C, preferably above 520°C.

11. The method according to claim 1, wherein, In step S6, along the flow direction of the light lubricating oil fraction and the heavy lubricating oil base oil fraction, the second hydrogenation catalyst includes catalyst I and catalyst II arranged sequentially. 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 10:1 to 3:

1.

12. The method according to claim 11, wherein, In step S6, the second hydrogenation catalyst further includes a hydrogenation catalyst II disposed downstream of the hydrogenation catalyst I; The hydrogenation 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 hydrogenation 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 hydrogenation catalyst II is greater than or equal to the total content of the fourth and fifth hydrogenation active metal components of the hydrogenation catalyst I. Preferably, the volume ratio of the hydrogenation catalyst I to the hydrogenation catalyst II is (30:70)-(60:40).

13. The method according to claim 11, wherein, In step S6, the conditions for the high-pressure hydrogenation reaction include: a hydrogen partial pressure of 3-25 MPa and a hydrogen-to-oil volume ratio of 200-3000; wherein 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; wherein the reaction temperature of catalyst I is 280-360℃, and the volume hourly space velocity is 0.3-2 h⁻¹. -1 The reaction temperature of catalyst II is 260-340℃, and the volume hourly space velocity is 0.3-2h. -1 .

14. A system for hydrogenating and regenerating waste lubricating oil using any one of claims 1-13, the system comprising: Slurry bed, flash distillation tower, solid-liquid separation unit, fractionation tower, medium-pressure fixed bed hydrogenation unit and high-pressure fixed bed hydrogenation unit; The product outlet of the slurry bed is fluidly connected to the inlet of the flash tower; the liquid outlet of the flash tower is fluidly connected to the inlet of the separation device, and optionally to the inlet of the slurry bed; the liquid outlet of the solid-liquid separation device is fluidly connected to the inlet of the medium-pressure fixed-bed hydrogenation device, the outlet of the medium-pressure fixed-bed hydrogenation device is fluidly connected to the inlet of the fractionation tower, and the outlets of the light lubricating oil fraction and the heavy lubricating oil base oil fraction of the fractionation tower are each independently fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

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