A method and system for hydroregenerating spent lubricating oil

Abstract

The present application relates to a kind of waste lubricating oil hydrogen regeneration method and system, the method comprises: S1, waste lubricating oil and oil-soluble catalyst are contacted in slurry bed and are carried out hydrogenation pretreatment, obtain hydrogenation mixture;S2, hydrogenation mixture is fractionated, and obtain gas, distillate oil and catalyst-containing tail oil;S3, at least part of catalyst-containing tail oil is carried out solid-liquid separation, and obtain heavy lubricating oil base stock and metal-containing tail residue;S4, in high-pressure fixed bed hydrogenation device, distillate oil and heavy lubricating oil base stock are contacted with hydrogenation catalyst respectively and carry out high-pressure hydrogenation reaction.The method of the present application has higher liquid product yield and catalyst utilization rate, and the color number and stability of regenerated lubricating oil product are better.

Description

Technical Field

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

[0002] Waste lubricating oil refers to the oil removed from various machines and equipment during use due to oxidation, thermal decomposition, and contamination by impurities, resulting in its physicochemical properties reaching the required replacement levels. Waste lubricating oil contains carcinogens such as polycyclic aromatic hydrocarbons and heavy metals, classifying it as "special hazardous waste." Untreated discharge of such oil can cause serious pollution. However, since the total impurities are less than 10%, the remainder can be recycled. Recycling waste lubricating oil not only conserves petroleum resources but also reduces environmental pollution. Furthermore, the price difference between waste lubricating oil purchased and recycled oil is several times, representing a significant profit margin and a promising market prospect, attracting widespread attention.

[0003] As the operating conditions of various mechanical equipment become increasingly demanding, higher requirements are placed on the performance of lubricating oils. Lubricating oil manufacturers have gradually increased the additive content, directly resulting in waste lubricating oil containing a large number of impurities from these additives. These impurities include calcium from detergents, chlorine from dispersants, zinc from antioxidants, silicon from antifoaming agents, antimony from extreme pressure agents, and sodium from rust inhibitors. These impurities are mostly uniformly dispersed in the waste lubricating oil as large organic molecules, making them difficult to remove through physical methods such as sedimentation and filtration. In the hydrogenation reactor, they easily deposit on the catalyst surface, causing catalyst poisoning and deactivation, affecting catalyst life, and leading to problems such as agglomeration and blockage. This results in increased reactor pressure drop, further contributing to the existing waste lubricating oil hydrogenation process's problems of short operating cycles, low product yield, difficulty in recovering bright oil components, insufficient product flexibility, and low catalyst utilization. Summary of the Invention

[0004] 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, reducing the severity of subsequent processing. It has a high yield of liquid phase products and a high catalyst utilization rate, and the regenerated lubricating oil product has better color and stability.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a method for hydrogenating and regenerating waste lubricating oil, the method comprising:

[0006] S1. The waste lubricating oil is contacted with the oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0007] S2. The hydrogenated mixture is fractionated to obtain gas, distillate oil and catalyst-containing tail oil;

[0008] S3. At least a portion of the catalyst-containing tail oil is subjected to solid-liquid separation to obtain metal tail residue and heavy lubricating oil base oil.

[0009] S4. In the high-pressure fixed-bed hydrogenation unit, the distillate oil and the heavy lubricating oil base oil are respectively brought into contact with the hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0010] Optionally, in step S1, the 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 waste lubricating oil is 100-3000 Nm³. 3 / m 3 .

[0011] 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);

[0012] The additive includes sulfur-containing substances; preferably, the sulfur-containing substances include one or more of carbon disulfide, sulfur, dimethyl disulfide and di-tert-butyl polysulfide.

[0013] 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 ,

[0014] 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 carboxyl groups and carboxylic acid groups to the hydrocarbon group R, a represents the molar ratio of noncoordinate oxygen atoms bonded to metal M to metal M, b represents the molar ratio of carboxylic acid groups to the total number of carboxyl groups and carboxylic acid groups, and c represents the molar ratio of the organic ligand to metal M, wherein:

[0015] The metal is a Group B and / or Group VIII metal with hydrogenation properties;

[0016] x is 1, 2 or 3, preferably 1 or 2;

[0017] a is a positive number from 0 to 5, preferably a positive number from 1 to 3;

[0018] b is a positive number between 0.01 and 0.99, preferably a positive number between 0.1 and 0.5;

[0019] c is a positive number between 0.5 and 10, preferably a positive number between 1 and 5.

[0020] 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%.

[0021] 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;

[0022] 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.

[0023] 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.

[0024] Optionally, in step S2, the fractionation conditions include: a pressure of -90 kPa to -99 kPa and a bottom temperature of 320-370 °C.

[0025] The distillate oil has a distillation range of 280-540℃, preferably 300-520℃; the catalyst-containing tail oil has a distillation range of 500℃ or higher, preferably greater than 520℃.

[0026] Optionally, step S3 includes: introducing a portion of the catalyst-containing tail oil into the slurry bed, and performing solid-liquid separation on the remaining portion of the catalyst-containing tail oil;

[0027] Preferably, the amount of catalyst-containing tail oil introduced into the slurry bed is 0-70% by weight of the total amount of catalyst-containing tail oil obtained in step S2, and more preferably 0-60% by weight.

[0028] Optionally, in step S4, along the flow direction of the distillate oil or the heavy lubricating oil base oil, the hydrogenation catalyst includes a hydrogenation protection catalyst and a hydrogenation treatment catalyst;

[0029] 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%.

[0030] Optionally, in step S4, along the flow direction of the distillate oil or the heavy lubricating oil base, the hydrotreating protection catalyst sequentially includes catalyst A, catalyst B and catalyst C; based on the total volume of the hydrotreating 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%.

[0031] 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).

[0032] 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; based on the total weight of the second support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight, and the second support contains phosphorus and halogens, with the halogen content calculated as elements being 0.1-6% by weight;

[0033] 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.

[0034] 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);

[0035] Along the flow direction of the distillate oil or the heavy lubricating oil base oil fraction, the hydrotreating catalyst sequentially includes catalyst I and catalyst II;

[0036] 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 first 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 first 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;

[0037] 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, calculated as metal oxide, is 3-8% 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;

[0038] More preferably, the weight content of the fifth hydrogenation active metal component of the hydrogenation catalyst Ib is 10-30% of the weight content of the fourth hydrogenation active metal component of the hydrogenation catalyst Ia, preferably 12-25%; preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (10-50):10.

[0039] 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, and the content of the second hydrogenation active metal component, calculated as metal oxide, is 16-52% by weight, based on the dry weight of the hydrogenation catalyst II; the second hydrogenation active component is selected from one or more of Co, Mo, Ni, and W; the sixth support is selected from alumina; 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;

[0040] Preferably, the volume ratio of the hydrogenation catalyst I to the hydrogenation catalyst II is (30:70)-(60:40).

[0041] Optionally, in step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydroprotected catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydroprotected catalyst, each independently 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 ;

[0042] 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 .

[0043] Optionally, in step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydrotreating catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydrotreating catalyst, each independently include: a hydrogen partial pressure of 3-25 MPa, 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 ;

[0044] 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 .

[0045] 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 fractionation tower, a solid-liquid separation device, and a high-pressure fixed-bed hydrogenation device.

[0046] The product outlet of the slurry bed is fluidly connected to the inlet of the fractionation tower; the catalyst-containing tail oil outlet of the fractionation tower is fluidly connected to the inlet of the solid-liquid separation device, and optionally to the inlet of the slurry bed; the liquid phase product outlet of the solid-liquid separation device is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device, and the distillate oil outlet of the fractionation tower is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

[0047] 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.

[0048] The advantages of the present invention through the above technical solution are as follows:

[0049] (1) This disclosure employs a slurry bed for hydrogen 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 and extending the operating cycle of the subsequent fixed bed unit. 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 in the 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.

[0050] (2) The oil-soluble catalyst used in the hydrogenation pretreatment method disclosed herein can be more uniformly dispersed in the waste lubricating oil to fully contact and react, thereby improving the reaction effect of catalytic hydrogenation pretreatment and the yield of liquid phase products.

[0051] (3) In this disclosure, the distillate oil and heavy lubricating oil base oil are sent to the downstream high-pressure fixed bed hydrogenation unit for high-pressure hydrogenation reaction, which effectively reduces the bottom temperature of the final hydrogenated base oil product distillation tower, prevents the generation of unstable substances at high temperature, and improves the color and stability of the regenerated lubricating oil product.

[0052] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0053] 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:

[0054] Figure 1 This is a flowchart illustrating a specific embodiment of the waste lubricating oil hydrogenation regeneration method disclosed herein. Detailed Implementation

[0055] 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.

[0056] A first aspect of the present invention provides a method for hydrogenating and regenerating waste lubricating oil, the method comprising:

[0057] S1. The waste lubricating oil is contacted with the oil-soluble catalyst in a slurry bed for hydrogenation pretreatment to obtain a hydrogenated mixture;

[0058] S2. The hydrogenated mixture is fractionated to obtain gas, distillate oil and catalyst-containing tail oil;

[0059] S3. At least a portion of the catalyst-containing tail oil is subjected to solid-liquid separation to obtain metal tail residue and heavy lubricating oil base oil.

[0060] S4. In the high-pressure fixed-bed hydrogenation unit, the distillate oil and the heavy lubricating oil base oil are respectively brought into contact with the hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0061] The method disclosed herein employs a slurry bed for hydropretreatment of the entire fraction of waste lubricating oil. This effectively removes metallic and non-metallic heteroatoms from the waste oil and saturates some polycyclic aromatic hydrocarbons, reducing the severity of subsequent processing and extending the operating cycle of the subsequent fixed-bed unit. Simultaneously, the oil-soluble catalyst used in the hydropretreatment is more uniformly dispersed in the waste lubricating oil to ensure sufficient contact for reaction, thereby improving the reaction efficiency of the catalytic hydropyrolysis reaction and the yield of liquid-phase products. Furthermore, a portion of the catalyst-containing tail oil is recycled back to the slurry bed, effectively improving catalyst utilization. This disclosure also sends the distillate oil and heavy lubricating oil base stock to a downstream high-pressure fixed-bed hydrotreating unit for high-pressure hydrogenation, effectively reducing the bottom temperature of the product distillation column, preventing the formation of unstable substances at high temperatures, and improving product color and stability.

[0062] In one specific embodiment of this disclosure, the 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 waste lubricating oil (i.e., the hydrogen-to-oil volume ratio) 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 .

[0063] In one specific embodiment of this disclosure, 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 can vary within a large range, for example, it can be 1:(0.5-5), preferably 1:(0.5-4).

[0064] In one specific embodiment of this disclosure, 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 is represented by R, which includes a carboxylate group and a carboxylic acid group. R represents a hydrocarbon group in the organic ligand. x represents the molar ratio of the total number of carboxylate groups and carboxylic acid groups to the hydrocarbon group R. a represents the molar ratio of noncoordinate oxygen atoms bonded to metal M to metal M. b represents the molar ratio of carboxylic acid groups to the total number of carboxylate groups and carboxylic acid groups. c represents the molar ratio of the organic ligand to 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] According to this disclosure, the oil-soluble catalyst includes an additive; the additive includes a sulfur-containing substance, which may include, but is not limited to, one or more of carbon disulfide, sulfur, dimethyl disulfide (DMDS) and di-tert-butyl polysulfide.

[0071] 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.

[0072] In one specific embodiment of this disclosure, the fractionation conditions in step S2 include: a pressure of -90 kPa to -99 kPa and a bottom temperature of 320-370°C; the distillation range of the fractional oil is 280-540°C, preferably 300-520°C; and the distillation range of the catalyst-containing tail oil is above 500°C, preferably above 520°C. In this embodiment, the total metal content of the obtained fractional oil is not greater than 5 μg / g, and the content of n-heptane insoluble matter is not greater than 100 μg / g.

[0073] According to this disclosure, step S3 includes: introducing a portion of the catalyst-containing tail oil into the slurry bed, and performing solid-liquid separation on the remaining portion of the catalyst-containing tail oil. In this disclosure, the proportion of the catalyst-containing tail oil introduced into the slurry bed relative to the total amount of catalyst-containing tail oil can vary within a wide range. In one specific embodiment, the amount of catalyst-containing tail oil introduced into the slurry bed is 0-70% by weight, preferably 0-60% by weight, of the total amount of catalyst-containing tail oil obtained in step S2. 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, and the heavy lubricating oil base oil accounts for more than 90% by weight of the catalyst-containing tail oil; the total metal content of the heavy lubricating oil base oil fraction is not greater than 20 μg / g, and the content of n-heptane insoluble matter is not greater than 150 μg / g.

[0074] 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, whereby the remaining portion of the catalyst-containing tail oil 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 tail oil 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.

[0075] In one specific embodiment of this disclosure, in step S4, along the flow direction of the distillate oil or the heavy lubricating oil base 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%.

[0076] 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 S4, along the flow direction of the distillate oil or the heavy lubricating oil base stock, 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%.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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).

[0081] In one specific embodiment of this disclosure, along the flow direction of the distillate oil or the heavy lubricating oil base oil fraction, the hydrotreating catalyst sequentially includes catalyst I and catalyst II;

[0082] 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.

[0083] 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, calculated as metal oxide, is 3-8% 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;

[0084] More preferably, the weight content of the fifth hydrogenation active metal component of the hydrogenation catalyst Ib is 10-30% of the weight content of the fourth hydrogenation active metal component of the hydrogenation catalyst Ia, preferably 12-25%; preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (10-50):10.

[0085] 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. 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 second hydrogenation active component is selected from one or more of Co, Mo, Ni, and W. The sixth support is selected from alumina. The catalyst II is a fluorine-free hydrogenation catalyst, and 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.

[0086] Preferably, the volume ratio of the hydrogenation catalyst I to the hydrogenation catalyst II is (30:70)-(60:40).

[0087] In one specific embodiment of this disclosure, in step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydroprotective catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydroprotective catalyst, each independently 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 .

[0088] In one specific embodiment of this disclosure, in step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydrotreating catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydrotreating catalyst, each independently 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 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 .

[0089] The method disclosed herein employs a high-performance hydrogenation catalyst and a novel catalyst gradation scheme, which can prevent the rapid rise in pressure drop in the high-pressure fixed-bed hydrogenation reactor, extend the operating cycle of the unit, and improve product quality.

[0090] In one specific embodiment of this disclosure, the method further includes step S5: introducing the reaction product obtained from the high-pressure hydrogenation reaction into a product fractionation tower for fractionation to obtain gas, hydrogenated diesel oil, medium-grade lubricating oil base oil and heavy-grade lubricating oil base oil.

[0091] In one specific embodiment of this disclosure, distillate oil and heavy lubricating oil base oils are respectively sent into storage tanks, and then introduced from the storage tanks into a high-pressure fixed-bed hydrogenation unit to contact the hydrogenation catalyst for high-pressure hydrogenation reaction.

[0092] 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 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 catalyst-containing tail oil outlet of the fractionation tower is fluidly connected to the inlet of the solid-liquid separation device, and optionally to the inlet of the slurry bed; the liquid-phase product outlet of the solid-liquid separation device is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device, and the distillate oil outlet of the fractionation tower is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

[0093] 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.

[0094] The present invention will be further described in detail below through examples.

[0095] 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.

[0096] Table 1 Properties of waste lubricating oil

[0097]

[0098]

[0099] 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.

[0100] Table 2

[0101]

[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. Fractionate the hydrogenated mixture to obtain gas, distillate oil, and catalyst-containing tail oil;

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

[0107] S4. In the high-pressure fixed-bed hydrogenation unit, distillate oil and heavy lubricating oil base oil are respectively contacted with the hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

[0108] The reaction conditions, product results, and product property analysis results for the above steps are shown in Table 5.

[0109] Along the flow direction of the heavy lubricating oil base, the hydroprotection catalyst includes catalyst A, catalyst B and catalyst C arranged in sequence, and the composition of the catalyst is shown in Table 3.

[0110] 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 halogen fluorine content (based on elemental composition) is 1.0 wt%.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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 (P2O5) is 1.8 wt%, and the halogen fluorine content (elemental) is 1.0 wt%.

[0115] 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.

[0116] 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.

[0117] 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%.

[0118] 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.

[0119] 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.

[0120] Table 3 Composition of catalysts A, B, and C

[0121]

[0122]

[0123] Along the flow direction of the distillate oil, the hydrotreating catalysts sequentially include hydrotreating catalyst Ib, hydrotreating catalyst Ia, and catalyst II. The composition of the catalysts is shown in Table 4.

[0124] The hydrogenation catalyst Ia contains 5 wt% NiO, 5 wt% MoO3, 20 wt% WO3, 5 wt% P2O5 and 65 wt% support.

[0125] The solution was prepared as follows: 3127g of Al2(SO4)3·18H2O and 338g of 98% sulfuric acid were dissolved in 4968g of deionized water to prepare solution I (pH 0.70, Al2O3 content 95g / L). 2070g of water glass (industrial grade, modulus: 3.26, SiO2 279.8g / L, Na2O 87.3g / L, iron oxide content 0.085% by weight, the same below) was diluted with water, and then 1.75g ​​of ferrous sulfate was added to prepare solution II (containing SiO2 80g / L, pH 12.61). Solution II was added to solution I under vigorous stirring to prepare a transparent silicon-aluminum mixed solution III, with a pH of 2.2 and a SiO2 / Al2O3 mass ratio of 1.0. Dilute ammonia (containing 5% NH3 by weight) and silicon-aluminum mixed solution III were mixed at a stirring speed of 3000 RPM. The ammonia was added at a rate that adjusted the pH of the mixture to within the range of 8.0 ± 0.3.

[0126] After the ammonia water was added, the resulting product was stirred at 55-60℃ for 10 hours, filtered, and the resulting filter cake was mixed with hot deionized water, slurried, and filtered. This step was repeated 4 times, and the filter cake was dried at 120℃ overnight. The precursor SAS-2 of the silicon-aluminum composite material carrier was obtained. Based on the weight of the added ferrous sulfate and the obtained precursor SAS-2, the iron content in the precursor of the silicon-aluminum composite material carrier, calculated as Fe2O3, was 0.3% by weight.

[0127] The precursor SAS-2 of the silicon-aluminum composite material carrier was extruded into cylindrical strips with a diameter of 1.5 mm. The cylindrical strips were then dried at 120°C for 5 hours and calcined at 600°C for 2 hours to obtain the catalyst carrier strips.

[0128] 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 5 wt%, 20 wt%, 5 wt%, and 5 wt%, respectively). 200 g of the above-mentioned 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 1 hour to obtain hydrogenation catalyst Ia.

[0129] 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 remainder alumina support.

[0130] Catalyst II contains 6.7 wt% NiO, 32.0 wt% WO3, 6.2 wt% MoO3, 5.9 wt% P2O5 and the balance support.

[0131] 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.

[0132] Table 4 Composition of hydrogenation catalysts Ia, II, and Ib

[0133]

[0134] Example 2-10

[0135] 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.

[0136] Comparative Example 1

[0137] 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.

[0138] Table 5

[0139]

[0140]

[0141]

[0142]

[0143] nature Chlorine content, mg / kg 70 Sulfur content, mg / kg 674 Total acid value, mgKOH / g 0.24 Fe, mg / kg <1 Ni, mg / kg <1 V, mg / kg <1 Na, mg / kg <1 Ca, mg / kg <1 Si, mg / kg 61 Nitrogen content, mg / kg 245 <![CDATA[Viscosity at 40°C, mm 2 / s]]> 31.71 <![CDATA[100°C viscosity, mm 2 / s]]> 5.535 <![CDATA[Density at 20℃, kg / m 3 > 854.5 Refractive index at 20℃ 1.4718 Residual char, % (w) <0.05 Total aromatics, % (w) 7.7

[0144] Table 7

[0145]

[0146] 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.

[0147] 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.

[0148] Table 6

[0149]

[0150] As can be seen from the above, the method disclosed herein has a high yield of liquid phase products and a high catalyst utilization rate, and the regenerated lubricating oil products have better color and stability.

[0151] 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.

[0152] 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.

[0153] 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 fractionated to obtain gas, distillate oil and catalyst-containing tail oil; S3. At least a portion of the catalyst-containing tail oil is subjected to solid-liquid separation to obtain metal tail residue and heavy lubricating oil base oil. S4. In the high-pressure fixed-bed hydrogenation unit, the distillate oil and the heavy lubricating oil base oil are respectively brought into contact with the hydrogenation catalyst to carry out high-pressure hydrogenation reaction.

2. The method according to claim 1, wherein, In step S1, the 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 waste 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 substances include 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 fractionation conditions include: a pressure of -90 kPa to -99 kPa and a bottom temperature of 320-370 °C. The distillate oil has a distillation range of 280-540℃, preferably 300-520℃; the catalyst-containing tail oil has a distillation range of 500℃ or higher, preferably greater than 520℃.

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

8. The method according to claim 1, wherein, In step S4, along the flow direction of the distillate oil or the heavy lubricating oil base 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%.

9. The method according to claim 8, wherein, In step S4, along the flow direction of the distillate oil or the heavy lubricating oil base oil, the hydrotreating 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%. 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; based on the total weight of the second support, the phosphorus content calculated as P2O5 is 0.1-8.0% by weight, and the second support contains phosphorus and halogens, with the halogen content calculated as elements being 0.1-6% by weight; 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); Along the flow direction of the distillate oil or the heavy lubricating oil base oil fraction, 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 first 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 first 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, calculated as metal oxide, is 3-8% by weight based on the dry basis 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; More preferably, the weight content of the fifth hydrogenation active metal component of the hydrogenation catalyst Ib is 10-30% of the weight content of the fourth hydrogenation active metal component of the hydrogenation catalyst Ia, preferably 12-25%; preferably, the volume ratio of the hydrogenation catalyst Ia to the hydrogenation catalyst Ib is (10-50):

10. 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, and the content of the second hydrogenation active metal component, calculated as metal oxide, is 16-52% by weight, based on the dry weight of the hydrogenation catalyst II; the second hydrogenation active component is selected from one or more of Co, Mo, Ni, and W; the sixth support is selected from alumina; 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).

10. The method according to claim 8, wherein, In step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydroprotected catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydroprotected catalyst, each independently 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 .

11. The method according to claim 8, wherein, In step S4, the conditions for the high-pressure hydrogenation reaction of the distillate oil in contact with the hydrotreating catalyst, and the conditions for the high-pressure hydrogenation reaction of the heavy lubricating oil base oil in contact with the hydrotreating catalyst, each independently 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 ; 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 .

12. A system for hydrogenating and regenerating waste lubricating oil using any one of claims 1-11, 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 column; The catalyst-containing tail oil outlet of the fractionation tower is fluidly connected to the inlet of the solid-liquid separation device, and optionally to the inlet of the slurry bed; the liquid product outlet of the solid-liquid separation device is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device, and the distillate oil outlet of the fractionation tower is fluidly connected to the inlet of the high-pressure fixed-bed hydrogenation device.

13. The system according to claim 12, 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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