Full resource high-value utilization device for lubricating oil fraction fractionation refining and accurate separation

Abstract

The lubricating oil fractionation refining and precise separation high-value utilization unit utilizes all resources. In the lubricating oil fractionation deacidification section, the lubricating oil fraction is fed into a pre-mixed pipeline mixer and a complexation extraction mixing and coalescing unit via a feed pump. Then, the complexation extraction mixing and coalescing unit is installed on one side of the deacidification settling tank, and its lower outlet is connected to a back-extraction mixing and coalescing unit. The upper outlet of the neutral oil settling tank is connected to a solvent oil phase-change distillation column, and the neutral oil pipeline is connected to the deacidified oil pipeline for mixing. The lower outlet of the neutral oil settling tank is connected to a complexation deacidifying agent phase-change distillation column, and naphthenic acid products are discharged from the bottom of the column. In the fractionation hydrorefining section, the mixed deacidified oil fraction passes sequentially through a hydrorefining reactor and a hydrosaturation reactor to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturated aromatics. The high-cycloalkyl hydrotreated oil is separated into industrial wax products by a urea composite dewaxing reactor and then connected to a vacuum tower for precise separation to obtain a series of low-pour-point lubricating oil base oils.

Description

Technical Field

[0001] This invention provides a device for the high-value utilization of all resources in the process of classifying, refining and precisely separating lubricating oil fractions, which relates to the petroleum refining field. Background Technology

[0002] Naphthenic crude oil is an indispensable and scarce high-quality resource for producing high-end specialty oils such as ultra-low pour point lubricating oil, ultra-high voltage transformer oil, ultra-low pour point refrigeration oil, environmentally friendly rubber oil, and high-performance asphalt. It holds significant strategic importance for industries such as national defense, aerospace, and power. The explosive growth of new energy vehicles is forcing the refining industry to transform and upgrade from a "fuel-based" to a "chemical-based and specialty oil" model. However, the "oil-to-specialty" conversion of naphthenic crude oil faces several challenges: ① Difficulty in differentiation: the wide or overlapping range of petroleum distillation fractions makes it difficult to meet the requirements of high-end specialty oils, resulting in lubricating oil resource utilization rates below 50% and difficulties in controlling asphalt production; ② Poor adaptability: existing refining processes can only reliably produce high-quality lubricating oil and asphalt from high-quality crude oil. Therefore, there is an urgent need to develop new molecular refining technologies to enable the production of high-end specialty oils from both naphthenic crude oil and intermediate-base crude oil.

[0003] Compared to lubricating base oils, high-purity naphthenic acids are priced 10,000-50,000 RMB / ton higher, and specialty industrial waxes are 03,000-10,000 RMB / ton higher. Both are important fine chemical raw materials with wide applications, especially naphthenic acids, which are invaluable high-quality grease-forming agents for lubricating greases. However, the most advanced lubricating oil fraction hydrorefining technology, while overcoming the shortcomings of the traditional three-step process (solvent dewaxing → solvent refining → clay supplementary refining) which is complex, has significant yield losses and pollution, still faces challenges. Given the crucial difference between paraffinic and naphthenic crude oils—the significant difference in naphthenic acid and wax content—hydrogenating and deoxygenating naphthenic acids to generate hydrocarbons and isomerizing and hydrogenating waxes to lower their pour point, requires substantial hydrogen consumption, increases costs, is difficult to control, and results in inconsistent oil source availability. Furthermore, the oil source is limited to specific naphthenic crude oils, preventing the use of intermediate-based crude oils and wasting valuable naphthenic acids and waxes. Therefore, there is an urgent need to develop a lubricating oil fraction refining technology that can adapt to a wider and more varied oil source, enabling the clean, efficient, and high-value utilization of all components. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing lubricating oil fraction refining technologies by developing a high-value utilization device for the graded refining and precise separation of lubricating oil fractions. The lubricating oil fractions are first deacidified and deacidified in a deacidification settling tank equipped with a mixing coalescer to recover naphthenic acids. Then, the deacidified lubricating oil fractions are passed through a hydrorefining reactor and a hydrosaturation reactor to remove sulfur, nitrogen, oxygen, chlorine, and other heteroatoms in the oil, and aromatics are hydrogenated to cycloalkanes. After separating industrial wax products in a urea composite dewaxing reactor, a series of low-pour-point lubricating oil base oil products are obtained through precise separation using a vacuum distillation tower. This invention improves adaptability to changes in oil source, expanding the oil source from naphthenic crude oil to intermediate-base crude oil, reducing hydrogen consumption, narrowing the distillation range, increasing added value, and achieving high-value utilization of all components, thus achieving the goal of refining lubricating oil fractions with low energy consumption.

[0005] The technical solution of the present invention:

[0006] This unit, designed for the full-resource high-value utilization of lubricating oil fractionation, refining, and precise separation, comprises a lubricating oil fractionation complexation and deacidification section, a fractionation hydrorefining section, a urea dewaxing section, and a vacuum precision separation section. In the lubricating oil fractionation and deacidification section, the lubricating oil fractionation feed pump outlet merges with the complexation deacidifying agent inlet, then sequentially connects to a preliminary premixing pipeline mixer and a complexation extraction mixing and coalescing device. The complexation extraction mixing and coalescing device is installed on one side of the upper part of the deacidification settling tank. The lower outlet of the deacidification settling tank is sequentially connected to a back-extraction mixing and coalescing device installed on the upper part of the neutralized oil settling tank. The upper outlet of the neutralized oil settling tank is connected to a solvent oil non-phase-change distillation column to recover solvent oil for return to the back-extraction feed pump. The neutral oil pipeline is connected to the deacidified distillate pipeline for mixing and recycling. The lower outlet of the neutral oil settling tank is connected to a non-phase-change distillation column containing a complexing deacidifying agent to recover the agent, which is then returned to the lubricating oil fraction feed pump for recycling. Naphthenic acid products are discharged from the bottom of the column. The mass ratio of lubricating oil fraction to complexing deacidifying agent is 0.1-5:1, the complexing deacidification temperature is 15-50℃, and the acid value of the distillate oil must be reduced to ≤0.3mgKOH / g. In the staged hydrorefining section, the mixed deacidified distillate oil flowing from the other side of the upper part of the deacidified settling tank passes sequentially through a hydrorefining reactor and a hydrosaturated reactor to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturated aromatics. The hydrogen partial pressure in the hydrorefining reactor is 6.0-20.0. The hydrogen partial pressure in the aromatic ring hydrogenation saturated reactor is 7.0-30.0 MPa, the temperature is 360-450℃, and the volume hourly space velocity is 0.1-1.0 h⁻¹.0 h⁻¹, hydrogen-to-oil volume ratio 800-2000 NL / m³, requiring the nitrogen, sulfur, oxygen, and heteroatom content of the high-cycloalkyl hydrogenated distillate to be less than 100 ppm and the aromatic ring content to be less than 1%; in the urea composite dewaxing section, the high-cycloalkyl hydrogenated distillate pipeline is mixed with the low-boiling-point solvent oil pipeline and then fed into the urea composite dewaxing reactor to separate industrial wax products and dewaxed oil. The high-cycloalkyl hydrogenated distillate and low-boiling-point solvent oil are mixed at a volume-to-solvent-to-oil ratio of 1-10:1, and the composition-to-mass ratio of the urea-water-alcohol solution used is 2-5:1:1-10. The dewaxed oil is fed into a phase-change-free distillation column. The low-boiling-point solvent oil recovered at the top of the column is recycled back to the low-boiling-point solvent oil pipeline for reuse, and the low-pour-point lubricating oil fraction is obtained from the bottom of the column; in the vacuum precision separation section, the dewaxed low-pour-point lubricating oil fraction is fed into a multi-side-line vacuum tower, from which the low-pour-point lubricating oil fraction is obtained from each side line of the vacuum tower. Different distillate oils meeting the final boiling point requirements are piped to external stripping towers. The stripping tower trays are precisely cut to ensure the initial boiling point meets product requirements. The stripped vapor phase is returned to the corresponding rectification section of each side line of the vacuum tower, resulting in a series of low-pour-point lubricating oil narrow-range base oils meeting the required distillation range. These are used to produce new energy cooling oils, transformer oils, rubber filler oils, low-pour-point greases, or low-pour-point lubricating oils. In a phase-change-free distillation tower, the high-temperature feedstock entering the tower is separated into bottom product and top vapor. The top vapor is pressurized and heated by a compressor to reheat the feedstock, yielding the top liquid product. The bottom product is discharged as a product after heat exchange with the feedstock. The pressurized and heated top vapor then uses phase-change heat to reheat the feedstock preheated by the bottom product.

[0007] In the lubricating oil fraction deacidification section, the mixing and coalescing unit is filled with hydrophilic fiber bundles. The lubricating oil fraction and the amine alcohol complexing deacidifying agent are pre-mixed via a pipeline mixer at an agent-to-oil mass ratio of 0.1-5:1 before being introduced into the mixing and coalescing unit. The amine alcohol complexing deacidifying agent adsorbs and extends onto the surface of the hydrophilic fiber bundles, forming a film that flows downwards. The lubricating oil fraction flows between the fibers of the hydrophilic fiber bundles and forms a non-dispersive contact reaction with the amine alcohol complexing deacidifying agent. Finally, the complexed extract condenses and separates at the lower end of the hydrophilic fiber bundles and enters the aqueous phase. The deacidified lubricating oil fraction flows out from between the middle and lower fibers of the hydrophilic fiber bundles and enters the oil phase. The amine alcohol complexing deacidifying agent is an alcohol-water-amine composite. The solvent is an alcohol selected from one or more of methanol, ethanol, n-propanol, isopropanol, or butanol, and the amine is selected from one or more of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, diisopropylamine, tripropylamine, n-butylamine, sec-butylamine, or tert-butylamine. The mass ratio of alcohol, water, and amine is 2-10:1-5:1. The aqueous complex extract is back-extracted with a low-boiling-point solvent oil to recover neutral oil. The extract oil and complex extract are recycled by low-energy distillation without phase change to recover low-boiling-point solvent oil and amine alcohol complex deacidifying agent, respectively, to obtain high-purity naphthenic acid product and neutral oil. The neutral oil is blended back into the deacidified lubricating oil fraction and enters the next hydrorefining process.

[0008] In the urea dewaxing section, the high-cycloalkyl hydrogenated distillate oil diluted with low-boiling-point solvent oil and the urea-water-alcohol solution are stirred and mixed evenly at 25-35℃ in the urea dewaxing reactor, and a complexation and containment reaction occurs to form a stable solid complex, which is separated from the dewaxing oil by sedimentation. The separated solid complex is washed again with low-boiling-point solvent oil and heated to 70-100℃. The complex decomposes into urea and n-alkanes. The urea can be recycled, and the n-alkanes are used as special industrial waxes. The washing oil and dewaxing oil are mixed and then the low-boiling-point solvent oil is recovered and recycled through phase-change-free distillation. The bottom material is used as a base oil for low-pour-point lubricating oil.

[0009] The features of the present invention will be described in detail through embodiments. Attached Figure Description

[0010] Appendix Figure 1 This is a schematic diagram of the process of the present invention.

[0011] Appendix Figure 1 The diagram is explained as follows:

[0012] 1. Pump 2. Pipeline mixer 3. Complex extraction mixing and coalescing unit 4. Back-extraction mixing and coalescing unit 5. Solvent oil phase change-free distillation column 6. Complex deacidifying agent phase change-free distillation column 7. Hydrogenation refining reactor 8. Hydrogenation saturation reactor 9. Urea composite dewaxing reactor 10. Vacuum distillation tower 11. Stripping tower A. Lubricating oil fraction B. Complex deacidifying agent C. Naphthenic acid D. Vacuum dry gas E. Special industrial wax F. Lubricating oil base oil

[0013] The process features of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0014] Example 1: A high-value utilization device for the classification, refining, and precise separation of lubricating oil fractions mainly consists of a lubricating oil fraction complexation and deacidification section, a classification and hydrorefining section, a urea dewaxing section, and a vacuum precision separation section. In the lubricating oil fraction complexation and deacidification section, the outlet of the lubricating oil fraction feed pump 1 merges with the inlet of an isopropanol-water-diethylamine complexation and deacidification agent with a mass ratio of 10:5:1, and then sequentially connects to a pre-mixed pipeline mixer 2 and a complexation extraction mixing and coalescing device 3. The complexation extraction mixing and coalescing device 3 is installed on one side of the upper part of the deacidification settling tank, and the lower outlet of the deacidification settling tank is sequentially connected to... The back-extraction mixing and coalescing device 4 is installed at the top of the neutral oil settling tank. The upper outlet of the neutral oil settling tank is connected to the solvent oil phase-change-free distillation column 5 to recover the solvent oil for recycling after returning it to the back-extraction feed pump. The neutral oil pipeline is connected to the deacidified distillate oil pipeline for mixing. The lower outlet of the neutral oil settling tank is connected to the complexing deacidifying agent phase-change-free distillation column 6 to recover the complexing deacidifying agent for recycling after returning it to the lubricating oil distillate oil feed pump. The naphthenic acid product is discharged from the bottom of the column. The mass ratio of lubricating oil distillate to complexing deacidifying agent is 0.3:1, the complexing deacidification temperature is 50℃, the deacidification rate is ≥99.5%, the acid value of the distillate oil is reduced to ≤0.01 mgKOH / g, and the recovery rate of complexing deacidifying agent is ≥99.5%. It saves more than 45% energy compared with the traditional solvent deacidification process. The acid value of high-purity naphthenic acid is ≥177mgKOH / g, which is better than the quality standard of No. 55 acid.

[0015] In the staged hydrorefining section, the mixed deacidified distillate flowing out from the other side of the top of the deacidification settling tank passes sequentially through hydrorefining reactor 7 and hydrosaturation reactor 8 to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturate aromatics. The hydrorefined oil then passes through hydrosaturation reactor 8 for deep aromatic ring hydrosaturation to generate cycloalkanes. The hydrogen partial pressure of hydrorefining reactor 7 is 6.0 MPa, the temperature is 400℃, and the volume hourly space velocity is 0.1 h⁻¹. The nitrogen, sulfur, oxygen, and heteroatomation content of the hydrorefined oil is less than 50 ppm. The hydrogen partial pressure of aromatic ring hydrosaturation reactor 8 is 30.0 MPa, the temperature is 360℃, the volume hourly space velocity is 3.0 h⁻¹, and the hydrogen-to-oil volume ratio is 2000 NL / m³. The hydrogen consumption is reduced by 42% compared to the full-fraction hydrorefining technology, and the aromatic ring hydrosaturation rate is over 99.5%, resulting in a high-cycloalkyl hydrorefined distillate with an aromatic ring content of less than 1%.

[0016] In the urea composite dewaxing section, the high-cycloalkyl hydrogenated distillate oil pipeline and the low-boiling-point solvent oil pipeline are mixed at a volumetric solvent-to-oil ratio of 1:1 and then enter the urea composite dewaxing reactor 9. A urea-water-isopropanol solution with a mass ratio of 2:1:1 is added, and after being stirred and mixed evenly at 25°C, a complexation and containment reaction occurs, forming a stable solid complex. This complex is separated from the dewaxing oil by sedimentation. The separated solid complex is washed again with low-boiling-point solvent oil and then heated to 70°C. The complex decomposes into urea and n-alkanes. The urea can be recycled, while the n-alkanes are used as special industrial wax F. The washing oil and dewaxing oil are mixed and then passed through a solvent oil phase-change-free distillation column 5 to recover and recycle the low-boiling-point solvent oil. The bottom material of the column is used as low-pour-point lubricating oil fraction E.

[0017] A phase-change-free distillation column separates the high-temperature feedstock into bottom product and top vapor. The top vapor is pressurized and heated by a compressor to reheat the feedstock, resulting in the top liquid product. The bottom product exchanges heat with the feedstock and is discharged as a product. The pressurized and heated top vapor uses the heat of phase change to reheat the feedstock that has been preheated by the bottom product.

[0018] In the vacuum distillation and precision separation section, the dewaxed low-pour-point lubricating oil fraction is fed into the multi-side-line vacuum distillation tower 10. Different fractions of oil with the required final boiling point are obtained from each side line of the vacuum distillation tower 10. Each fraction of oil is then connected to each stripping tower 11 attached to the vacuum distillation tower 10. The stripping plates of the stripping tower 11 are clearly cut to control the initial boiling point to meet the product requirements. The stripped vapor phase is returned to the upper part of the rectification section corresponding to each side line of the vacuum distillation tower 10, resulting in a series of low-pour-point lubricating oil narrow-range base oils with a distillation range of 27°C. These base oils are used to produce new energy cooling oil, transformer oil, rubber filler oil, low-pour-point grease, or low-pour-point lubricating oil.

[0019] Example 2: A high-value utilization device for the classification, refining, and precise separation of lubricating oil fractions mainly consists of a lubricating oil fraction complexation and deacidification section, a classification and hydrorefining section, a urea dewaxing section, and a vacuum precision separation section. In the lubricating oil fraction complexation and deacidification section, the outlet of the lubricating oil fraction feed pump 1 merges with the inlet of an isopropanol-water-diethylamine complexation and deacidification agent with a mass ratio of 7:2:1, and then sequentially connects to a preliminary premixed pipeline mixer 2 and a complexation extraction mixing and coalescing device 3. The complexation extraction mixing and coalescing device 3 is installed on one side of the upper part of the deacidification settling tank, and the lower outlet of the deacidification settling tank is sequentially connected to the pipeline mixer 2 and the complexation extraction mixing and coalescing device 3. The process involves connecting a back-extraction mixing and coalescing device 4 installed at the top of the neutral oil settling tank, connecting a solvent oil phase-change-free distillation column 5 at the top outlet of the settling tank to recover solvent oil for recycling after returning it to the back-extraction feed pump, connecting the neutral oil pipeline to the deacidified distillate pipeline for mixing, connecting a complexing deacidifying agent phase-change-free distillation column 6 at the bottom outlet of the settling tank to recover the complexing deacidifying agent for recycling after returning it to the lubricating oil distillate feed pump, and discharging naphthenic acid products from the bottom of the column. The mass ratio of lubricating oil distillate to complexing deacidifying agent is 0.3:1, the complexing deacidification temperature is 30℃, the deacidification rate is ≥99%, the acid value of the distillate oil is reduced to ≤0.02 mgKOH / g, and the recovery rate of the complexing deacidifying agent is ≥99.5%, saving more than 50% energy compared to the traditional solvent deacidification process; the high-purity naphthenic acid acid value is ≥177 mgKOH / g, which is better than the No. 55 acid quality standard.

[0020] In the staged hydrorefining section, the mixed deacidified distillate flowing out from the other side of the top of the deacidification settling tank passes sequentially through hydrorefining reactor 7 and hydrosaturation reactor 8 to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturate aromatics. The hydrorefined oil then passes through hydrosaturation reactor 8 for deep aromatic ring hydrosaturation to generate cycloalkanes. The hydrogen partial pressure of hydrorefining reactor 7 is 8.0 MPa, the temperature is 350℃, and the volume hourly space velocity is 0.3 h⁻¹. The nitrogen, sulfur, oxygen, and heteroatomation content of the hydrorefined oil is less than 50 ppm. The hydrogen partial pressure of aromatic ring hydrosaturation reactor 8 is 20.0 MPa, the temperature is 380℃, the volume hourly space velocity is 1.0 h⁻¹, and the hydrogen-to-oil volume ratio is 1500 NL / m³. The hydrogen consumption is reduced by 40% compared to the full-fraction hydrorefining technology, and the aromatic ring hydrosaturation rate is over 99%, resulting in a high-cycloalkyl hydrorefined distillate with an aromatic ring content of less than 1%.

[0021] In the urea composite dewaxing section, the high-cycloalkyl hydrogenated distillate oil pipeline and the low-boiling-point solvent oil pipeline are mixed at a volumetric solvent-to-oil ratio of 5:1 and then enter the urea composite dewaxing reactor 9. A urea-water-isopropanol solution with a mass ratio of 2:1:2 is added, and after being stirred and mixed evenly at 30°C, a complexation and containment reaction occurs, forming a stable solid complex. This complex is separated from the dewaxing oil by sedimentation. The separated solid complex is washed again with low-boiling-point solvent oil and then heated to 85°C. The complex decomposes into urea and n-alkanes. The urea can be recycled, while the n-alkanes are used as special industrial wax F. The washing oil and dewaxing oil are mixed and then passed through a solvent oil phase-change-free distillation column 5 to recover and recycle the low-boiling-point solvent oil. The bottom material of the column is used as low-pour-point lubricating oil fraction E.

[0022] A phase-change-free distillation column separates the high-temperature feedstock into bottom product and top vapor. The top vapor is pressurized and heated by a compressor to reheat the feedstock, resulting in the top liquid product. The bottom product exchanges heat with the feedstock and is discharged as a product. The pressurized and heated top vapor uses the heat of phase change to reheat the feedstock that has been preheated by the bottom product.

[0023] In the vacuum distillation and precision separation section, the dewaxed low-pour-point lubricating oil fraction is fed into the multi-side-line vacuum distillation tower 10. Different fractions of oil with the required final boiling point are obtained from each side line of the vacuum distillation tower 10. Each fraction of oil is then connected to each stripping tower 11 attached to the vacuum distillation tower 10. The stripping plates of the stripping tower 11 are clearly cut to control the initial boiling point to meet the product requirements. The stripped vapor phase is returned to the upper part of the rectification section corresponding to each side line of the vacuum distillation tower 10, resulting in a series of low-pour-point lubricating oil narrow-range base oils with a distillation range of 28°C. These base oils are used to produce new energy cooling oil, transformer oil, rubber filler oil, low-pour-point grease, or low-pour-point lubricating oil.

[0024] Example 3: A high-value utilization device for the classification, refining, and precise separation of lubricating oil fractions mainly consists of a lubricating oil fraction complexation and deacidification section, a classification and hydrorefining section, a urea dewaxing section, and a vacuum precision separation section. In the lubricating oil fraction complexation and deacidification section, the outlet of the lubricating oil fraction feed pump 1 merges with the inlet of an isopropanol-water-diethylamine complexation and deacidification agent with a mass ratio of 2:1:1, and then sequentially connects to a pre-mixed pipeline mixer 2 and a complexation extraction mixing and coalescing device 3. The complexation extraction mixing and coalescing device 3 is installed on one side of the upper part of the deacidification settling tank, and the lower outlet of the deacidification settling tank is sequentially connected to the pipeline mixer 2 and the complexation extraction mixing and coalescing device 3. The process involves connecting a back-extraction mixing and coalescing device 4 installed at the top of the neutral oil settling tank, connecting a solvent oil phase-change-free distillation column 5 at the top outlet of the settling tank to recover solvent oil for recycling after returning it to the back-extraction feed pump, connecting the neutral oil pipeline to the deacidified distillate pipeline for mixing, connecting a complexing deacidifying agent phase-change-free distillation column 6 at the bottom outlet of the settling tank to recover the complexing deacidifying agent for recycling after returning it to the lubricating oil distillate feed pump, and discharging naphthenic acid products from the bottom of the column. The mass ratio of lubricating oil distillate to complexing deacidifying agent is 0.1:1, the complexing deacidification temperature is 15℃, the deacidification rate is ≥99%, the acid value of the distillate oil is reduced to ≤0.02 mgKOH / g, and the recovery rate of the complexing deacidifying agent is ≥99.5%, saving more than 70% energy compared to the traditional solvent deacidification process; the high-purity naphthenic acid acid value is ≥170 mgKOH / g, which is better than the No. 55 acid quality standard.

[0025] In the staged hydrorefining section, the mixed deacidified distillate flowing out from the other side of the top of the deacidification settling tank passes sequentially through hydrorefining reactor 7 and hydrosaturation reactor 8 to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturate aromatics. The hydrorefined oil then passes through hydrosaturation reactor 8 for deep aromatic ring hydrosaturation to generate cycloalkanes. The hydrogen partial pressure of hydrorefining reactor 7 is 20.0 MPa, the temperature is 300℃, and the volume hourly space velocity is 1.0 h⁻¹. The nitrogen, sulfur, oxygen, and heteroatomation content of the hydrorefined oil is less than 35 ppm. The hydrogen partial pressure of aromatic ring hydrosaturation reactor 8 is 7.0 MPa, the temperature is 450℃, the volume hourly space velocity is 0.1 h⁻¹, and the hydrogen-to-oil volume ratio is 800 NL / m³. The hydrogen consumption is reduced by 39% compared to the full-fraction hydrorefining technology, and the aromatic ring hydrosaturation rate is over 99%, resulting in a high-cycloalkyl hydrorefined distillate with an aromatic ring content of less than 1%.

[0026] In the urea composite dewaxing section, the high-cycloalkyl hydrogenated distillate oil pipeline and the low-boiling-point solvent oil pipeline are mixed at a volumetric solvent-to-oil ratio of 10:1 and then enter the urea composite dewaxing reactor 9. A urea-water-isopropanol solution with a mass ratio of 5:1:10 is added, and after being stirred and mixed evenly at 35°C, a complexation and containment reaction occurs, forming a stable solid complex. This complex is separated from the dewaxing oil by sedimentation. The separated solid complex is washed again with low-boiling-point solvent oil and then heated to 100°C. The complex decomposes into urea and n-alkanes. The urea can be recycled, while the n-alkanes are used as special industrial wax F. The washing oil and dewaxing oil are mixed and then passed through a solvent oil phase-change-free distillation column 5 to recover and recycle the low-boiling-point solvent oil. The bottom material of the column is used as low-pour-point lubricating oil fraction E.

[0027] A phase-change-free distillation column separates the high-temperature feedstock into bottom product and top vapor. The top vapor is pressurized and heated by a compressor to reheat the feedstock, resulting in the top liquid product. The bottom product exchanges heat with the feedstock and is discharged as a product. The pressurized and heated top vapor uses the heat of phase change to reheat the feedstock that has been preheated by the bottom product.

[0028] In the vacuum distillation and precision separation section, the dewaxed low-pour-point lubricating oil fraction is fed into the multi-side-line vacuum distillation tower 10. Different fractions of oil with the required final boiling point are obtained from each side line of the vacuum distillation tower 10. Each fraction of oil is then connected to each stripping tower 11 attached to the vacuum distillation tower 10. The stripping plates of the stripping tower 11 are clearly cut to control the initial boiling point to meet the product requirements. The stripped vapor phase is returned to the upper part of the rectification section corresponding to each side line of the vacuum distillation tower 10, resulting in a series of low-pour-point lubricating oil narrow-range base oils with a distillation range of 28°C. These base oils are used to produce new energy cooling oil, transformer oil, rubber filler oil, low-pour-point grease, or low-pour-point lubricating oil.

[0029] The lubricating oil fractionation, grading, refining, and precise separation device provided by this invention enables the expansion of the oil source from naphthenic crude oil to intermediate base crude oil, which accounts for more than 50%, increasing the source of feedstock oil by more than 20 times. The utilization rate of lubricating oil fractions is increased from ≤50% to full-component high-value utilization, the distillation range is narrowed from the current ≥55℃ to ≤30℃, and the added value is increased by ≥30%. This maximizes the low-cost and controllable production of high-grade low-pour-point base oils, specialty waxes, and high-purity naphthenic acid products of different grades.

Claims

1. A device for the full-resource high-value utilization of lubricating oil fractionation, refining, and precise separation, characterized in that... The unit is divided into a lubricating oil fraction complexation and deacidification section, a staged hydrorefining section, a urea complex dewaxing section, and a vacuum precision separation section. In the lubricating oil fraction complexation and deacidification section, the lubricating oil fraction feed pump outlet merges with the complexation deacidifying agent inlet, and then sequentially connects to a preliminary premixing pipeline mixer and a complexation extraction mixing and coalescing device. The complexation extraction mixing and coalescing device is installed on one side of the upper part of the deacidification settling tank, and the lower outlet of the deacidification settling tank is sequentially connected to a back-extraction mixing and coalescing device installed on the upper part of the neutral oil settling tank. The upper outlet of the neutral oil settling tank is connected to a solvent oil non-phase change distillation column to recover the solvent oil, which is then returned to the back-extraction feed pump for recycling. The neutral oil pipeline is connected to the deacidified distillate oil pipeline for mixing. The lower outlet of the neutral oil settling tank is connected to a complexing deacidifying agent non-phase change distillation column to recover the complexing deacidifying agent, which is then returned to the lubricating oil distillate oil feed pump for recycling. Naphthenic acid product is discharged from the bottom of the column. The mass ratio of lubricating oil distillate to complexing deacidifying agent is 0.1-5:1, the complexing deacidification temperature is 15-50℃, and the acid value of the distillate oil is ≤0.

3. mgKOH / g; In the staged hydrorefining section, the mixed deacidified distillate oil flowing out from the other side of the upper part of the deacidification settling tank passes sequentially through the hydrorefining reactor and the hydrosaturation reactor to remove sulfur, nitrogen, oxygen, heteroatoms, and hydrosaturated aromatics. The hydrogen partial pressure in the hydrorefining reactor is 6.0-20.0 MPa, the temperature is 300-400℃, and the volume hourly space velocity is 0.1-1.0 h⁻¹. -1 The hydrogen partial pressure in the aromatic ring hydrogenation saturated reactor is 7.0-30.0 MPa, the temperature is 360-450℃, and the volume hourly space velocity is 0.3-3.0 h⁻¹. -1 Hydrogen-to-oil volume ratio 800-2000 NL / m 3 The high-cycloalkyl hydrogenated distillate oil has a nitrogen, sulfur, oxygen, and heteroatom content of less than 100 ppm and an aromatic ring content of less than 1%. In the urea-based dewaxing section, the high-cycloalkyl hydrogenated distillate oil pipeline is mixed with the low-boiling-point solvent oil pipeline and then fed into the urea-based dewaxing reactor to separate industrial wax products and dewaxed oil. The high-cycloalkyl hydrogenated distillate oil and low-boiling-point solvent oil are mixed at a volumetric solvent-to-oil ratio of 1-10:1, and the composition-to-mass ratio of the urea-water-alcohol solution used is 2-5:1:1-10. The dewaxed oil is fed into a phase-change-free distillation column. The low-boiling-point solvent oil recovered at the top of the column is recycled back to the low-boiling-point solvent oil pipeline for reuse, and the low-pour-point lubricating oil fraction is obtained at the bottom of the column. In the vacuum distillation precision separation section, the dewaxed low-pour-point lubricating oil fraction is fed into a multi-side-line vacuum distillation column. Different distillate oils with final boiling points meeting requirements are obtained. Each distillate oil pipeline is then connected to a stripping tower attached to the vacuum distillation tower. The stripping tower trays are clearly cut to control the initial boiling point to meet product requirements. The stripping vapor pipeline returns to the upper part of the rectification section corresponding to each side line of the vacuum distillation tower, resulting in a series of low-pour-point lubricating oil narrow-range base oils with the required distillation range. The phase-change-free distillation tower separates the high-temperature feedstock entering the distillation tower into bottom material and top vapor. The top vapor is pressurized and heated by a compressor to reheat the feedstock, resulting in the top liquid product. The bottom material exchanges heat with the feedstock and is discharged as a product. The pressurized and heated top vapor uses the phase change heat to reheat the feedstock that has been preheated by the bottom material.

2. The device for high-value utilization of all resources for the fractionation, refining, and precise separation of lubricating oil fractions according to claim 1, characterized in that... In the lubricating oil fraction complexation and deacidification section, the mixing and coalescing unit is filled with hydrophilic fiber bundles. The lubricating oil fraction and the amine alcohol complexation deacidifying agent are pre-mixed via a pipeline mixer at an agent-to-oil mass ratio of 0.1-5:1 before being introduced into the mixing and coalescing unit. The amine alcohol complexation deacidifying agent adsorbs and extends onto the surface of the hydrophilic fiber bundles, forming a film that flows downwards. The lubricating oil fraction flows between the fibers of the hydrophilic fiber bundles and forms a non-dispersive contact reaction with the amine alcohol complexation deacidifying agent. Finally, the complexed extract condenses and separates at the lower end of the hydrophilic fiber bundles and enters the aqueous phase. The deacidified lubricating oil fraction flows out from between the middle and lower fibers of the hydrophilic fiber bundles and enters the oil phase. The amine alcohol complexation deacidifying agent is an alcohol-water-amine composite solution. The alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, or butanol, and the amine is one or more of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, diisopropylamine, tripropylamine, n-butylamine, sec-butylamine, or tert-butylamine. The mass ratio of alcohol, water, and amine is 2-10:1-5:

1. The aqueous complex extract is back-extracted with a low-boiling-point solvent oil to recover neutral oil. The extract oil and complex extract are recycled by low-energy distillation without phase change to recover low-boiling-point solvent oil and amine alcohol complex deacidifying agent, respectively, to obtain high-purity naphthenic acid product and neutral oil. The neutral oil is blended back into the deacidified lubricating oil fraction and enters the next hydrorefining process.

3. The device for high-value utilization of all resources for the fractionation, refining, and precise separation of lubricating oil fractions according to claim 1, characterized in that... In the urea dewaxing section, the high-cycloalkyl hydrogenated distillate oil diluted with low-boiling-point solvent oil and the urea-water-alcohol solution are stirred and mixed evenly at 25-35℃ in the urea dewaxing reactor, and a complexation and containment reaction occurs to form a stable solid complex, which is separated from the dewaxing oil by sedimentation. The separated solid complex is washed again with low-boiling-point solvent oil and heated to 70-100℃. The complex decomposes into urea and n-alkanes. The urea can be recycled, and the n-alkanes are used as special industrial waxes. The washing oil and dewaxing oil are mixed and then the low-boiling-point solvent oil is recovered and recycled through phase-change-free distillation. The bottom material is used as a base oil for low-pour-point lubricating oil.

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