A production process of low freezing and high viscosity index lubricating oil based on solvent refining
Patent Information
- Application Number
- CN202611022511.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-10
- Publication Date
- 2026-10-13
AI Technical Summary
[0005]本发明的目的在于提供一种基于溶剂精制的低凝高粘指数润滑油生产工艺，旨在解决现有工艺采用单一萃取溶剂，难以充分脱除原料中的重芳烃、极性硫化物及氮化物，造成油品粘度指数偏低、温变性能差，适用场景受限的技术问题
[0013]本发明的一种基于溶剂精制的低凝高粘指数润滑油生产工艺，采用以下步骤：将减压三线馏分油加热，脱除游离水、轻组分与机械杂质，得到预处理原料油；采用糠醛与轻质烷烃复配溶剂，送入逆流萃取塔萃取，得到油相与富溶剂相混合液；将萃取混合液置于沉降罐中静置分层，分别收集精制油相与富溶剂相；将富溶剂相经常压蒸馏，通入水蒸气汽提，回收溶剂循环回用；将精制油相采用丙酮-苯-甲苯三元溶剂进行溶剂脱蜡，并过滤分离蜡膏与脱蜡油；向脱蜡油中加入活性白土，过滤除杂制得润滑油成品基础油；在上述中，采用糠醛与轻质烷烃复配萃取溶剂搭配丙酮-苯-甲苯三元脱蜡溶剂，可高效脱除原料中的重芳烃、极性硫化物及氮化物等劣化组分；另外，用丙酮-苯-甲苯三元溶剂进行低温脱蜡，低温溶解性能优异，可使油品中的长链正构烷烃充分结晶析出，大幅降低蜡质残留量，有效降低成品凝点，保障油品在低温环境下具备良好流动性，能够满足高寒地区及低温设备的使用需求，实现了能够提升润滑油基础油的粘度指数，改善油品温变性能，大幅拓宽产品适用场景。
Smart Images
Figure CN122898290A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lubricant production technology, and in particular to a solvent-refined process for producing low-pour-point, high-viscosity-index lubricants. Background Technology
[0002] Lubricating oil base oils are the core raw materials for various industrial and automotive lubricants. Their pour point, viscosity index, purity, and thermal stability directly determine the performance, applicable operating conditions, and service life of the final oil product. Currently, conventional lubricating oil base oils are generally processed from petroleum distillate oils. Among them, vacuum distillate oils are the mainstream raw material for preparing general-purpose lubricating oil base oils due to their moderate composition and sufficient production capacity.
[0003] Traditional solvent refining processes typically use single extraction solvents such as furfural or phenols to refine the raw oil. Subsequent processes, such as conventional single-component solvent dewaxing and simple filtration to remove impurities, can initially remove some impurities and waxes from the raw oil, producing base oil products that basically meet the needs of low-end lubricating oils.
[0004] Existing processes use a single extraction solvent, which makes it difficult to fully remove heavy aromatics, polar sulfides, and nitrogen compounds from the raw materials, resulting in low oil viscosity index, poor temperature response, and limited applicability. Summary of the Invention
[0005] The purpose of this invention is to provide a solvent-refined production process for low-pour-point, high-viscosity-index lubricating oils. This process aims to solve the technical problems of existing processes that use a single extraction solvent, which makes it difficult to fully remove heavy aromatics, polar sulfides, and nitrides from the raw materials, resulting in low viscosity index, poor temperature response, and limited applicability of the oil.
[0006] To achieve the above objectives, the present invention employs a solvent-refined process for producing low-pour-point, high-viscosity-index lubricating oil, comprising the following steps: The vacuum distillate fraction is heated to remove free water, light components and mechanical impurities, resulting in a pretreated feedstock. A mixture of furfural and light alkane solvents was fed into a countercurrent extraction tower for extraction, resulting in a mixture of oil phase and solvent-rich phase. The extraction mixture was placed in a settling tank and allowed to stand to separate into layers. The refined oil phase and the solvent-rich phase were collected separately. The solvent-rich phase is distilled under normal pressure, stripped with steam, and the recovered solvent is recycled. The refined oil phase was dewaxed using an acetone-benzene-toluene ternary solvent, and the wax paste and dewaxed oil were separated by filtration. Activated clay is added to the dewaxed oil, and the mixture is filtered to remove impurities to obtain the base oil for the finished lubricating oil.
[0007] In the step of heating the vacuum distillate oil to remove free water, light components, and mechanical impurities to obtain pretreated feedstock oil: The reduced pressure distillate oil is transported to the heating equipment, gradually heated to 95°C, and kept at a constant temperature. The free water and small molecule light components contained in the oil are removed by flash evaporation through the heating effect. Filtration removes suspended solid mechanical impurities from oil products; The processed oil was tested for moisture content, and materials with a water content of ≤0.03% were selected as pre-treated feed oil.
[0008] In the step of using furfural and light alkane as a compound solvent and feeding it into a countercurrent extraction tower to obtain a mixture of oil phase and solvent-rich phase: A compound extraction solvent was prepared by mixing furfural and light alkanes. The compound solvent and the pretreated raw oil were fed into the countercurrent extraction tower at a volume ratio of 2:1. The internal temperature of the extraction tower is adjusted to 60–120°C and the pressure to 0.3–0.5 MPa to ensure sufficient countercurrent contact and reaction between the two phases. Once the extraction reaction is complete, collect the mixture of oil phase and solvent-rich phase flowing out of the tower.
[0009] In the step of placing the extraction mixture in a settling tank for sedimentation and separating the layers, and collecting the refined oil phase and the solvent-rich phase separately: The extracted mixture is transferred to a settling tank, and the temperature inside the tank is kept constant at 70°C. Seal the settling tank and keep it in a static state for 40 minutes, allowing the two phases to naturally separate into layers based on the density difference. After observing the layered interface and confirming that the two phases are completely separated, the upper refined oil phase is first extracted, and then the lower solvent-rich phase containing impurities is collected to complete the two-phase separation and collection operation.
[0010] In the step of distilling the solvent-rich phase under normal pressure, stripping it with steam, and recovering the solvent for recycling: The collected solvent-rich phase was fed into an atmospheric distillation apparatus and heated to 150°C. Steam stripping is performed by introducing 4% of the total mass of the solvent-rich phase with water vapor. The solvent and dissolved impurity components are separated by a combination of distillation and stripping. The purified compound solvent is collected and transported to the extraction process for recycling.
[0011] In the step of solvent dewaxing the refined oil phase using an acetone-benzene-toluene ternary solvent and filtering to separate the wax paste and dewaxed oil: Add acetone-benzene-toluene ternary dewaxing solvent to the refined oil phase and mix thoroughly. Cool the mixture to -28°C and keep it at a constant temperature. The waxy components in the oil crystallize out. The cooled material is fed into a filtration device for solid-liquid separation, and the solid wax paste and liquid dewaxing oil are collected to complete the dewaxing process.
[0012] In the step of adding activated clay to dewaxed oil and filtering to remove impurities to obtain the base oil for the finished lubricating oil: Add 3% by weight of activated clay to the dewaxed oil and stir to mix the materials evenly. The system was heated to 130℃, kept at that temperature and continuously reacted for 35 minutes, using activated clay to adsorb residual gum, pigments and trace impurities in the oil. After the reaction is complete, filter to remove waste clay and solid impurities to obtain the finished lubricating oil base oil.
[0013] This invention discloses a solvent-refined process for producing low-pour-point, high-viscosity-index lubricating oil, comprising the following steps: heating vacuum distillate to remove free water, light components, and mechanical impurities, yielding a pretreated feedstock oil; using furfural and light alkane compound solvents, extracting the oil phase and solvent-rich phase in a countercurrent extraction tower to obtain a mixture; placing the extraction mixture in a settling tank for sedimentation and separation, collecting the refined oil phase and solvent-rich phase separately; distilling the solvent-rich phase under normal pressure, stripping it with steam, and recycling the recovered solvent; dewaxing the refined oil phase using an acetone-benzene-toluene ternary solvent, and filtering to separate the wax paste and dewaxed oil; adding activated clay to the dewaxed oil and filtering to remove impurities. The resulting base oil for lubricating oil is obtained by using furfural and light alkanes as a compound extraction solvent, combined with an acetone-benzene-toluene ternary dewaxing solvent. This effectively removes deteriorating components such as heavy aromatics, polar sulfides, and nitrides from the raw materials. In addition, the acetone-benzene-toluene ternary solvent is used for low-temperature dewaxing, which has excellent low-temperature solubility and allows long-chain n-alkanes in the oil to fully crystallize and precipitate, significantly reducing the amount of wax residue, effectively lowering the pour point of the finished product, and ensuring that the oil has good fluidity in low-temperature environments. This meets the needs of cold regions and low-temperature equipment, improves the viscosity index of the lubricating oil base oil, enhances the temperature change performance of the oil, and greatly expands the applicable scenarios of the product. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is a flowchart of the production process of low pour point and high viscosity index lubricating oil based on solvent refining according to the present invention.
[0016] Figure 2 This is a flowchart of steps S100 of the present invention.
[0017] Figure 3 This is a flowchart of steps S200 of the present invention.
[0018] Figure 4 This is a flowchart of steps S300 of the present invention.
[0019] Figure 5 This is a flowchart of steps S400 of the present invention.
[0020] Figure 6 This is a flowchart of steps S500 of the present invention.
[0021] Figure 7 This is a flowchart of steps S600 of the present invention. Detailed Implementation
[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.
[0023] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0024] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."
[0025] Please see Figures 1-7 This invention provides a solvent-refined process for producing low-pour-point, high-viscosity-index lubricating oil, comprising the following steps: S100: The vacuum distillate oil is heated to remove free water, light components and mechanical impurities, resulting in a pretreated feedstock oil.
[0026] In this embodiment, the vacuum distillate oil is heated to remove free water, light components, and mechanical impurities, yielding a pretreated feedstock oil. The specific process is as follows: S101: Transport the vacuum distillate oil to the heating equipment, gradually raise the temperature to 95°C, and maintain the temperature. Use the heating effect to flash evaporate and remove free water and small molecule light components contained in the oil. S102: Filtering removes suspended solid mechanical impurities from oil products; S103: The moisture content of the treated oil is tested, and materials with a water content of ≤0.03% are selected as pre-treated raw oil.
[0027] In the above process, the vacuum distillate oil is first transported to the heating equipment and gradually heated to 95°C, which is then maintained at a constant temperature. The free water and small light components contained in the oil are removed by flash evaporation due to the heating effect. Then, the suspended solid mechanical impurities in the oil are removed by filtration. The water content of the treated oil is then tested, and materials with a water content ≤0.03% are selected as pretreatment feed oil. In the above process, the heating temperature is strictly controlled at 95°C, which can ensure that free water, light components and mechanical impurities are fully removed, and prevent the feed oil from excessive vaporization and component deterioration due to excessive temperature, thereby reducing feed loss.
[0028] S200: Furfural and light alkane are mixed in a solvent and fed into a countercurrent extraction tower for extraction to obtain a mixture of oil phase and solvent-rich phase.
[0029] In this embodiment, a compound solvent of furfural and light alkanes is used and fed into a countercurrent extraction tower for extraction to obtain a mixture of oil phase and solvent-rich phase. The specific process is as follows: S201: A compound extraction solvent is prepared by mixing furfural and light alkanes; S202: The compound solvent and the pretreated raw oil are fed into the countercurrent extraction tower separately according to the volumetric solvent-to-oil ratio of 2:1; S203: Adjust the internal temperature of the extraction tower to 60-120℃ and the pressure to 0.3-0.5MPa to ensure sufficient contact and reaction between the two phases in countercurrent flow; S204: After the extraction reaction is complete, collect the mixture of oil phase and solvent-rich phase flowing out of the tower.
[0030] In the above process, furfural and light alkanes are first mixed to prepare a compound extraction solvent. Then, the compound solvent and the pretreated feed oil are fed into a countercurrent extraction tower at a volume ratio of 2:1. The temperature inside the extraction tower is then adjusted to 60-120°C and the pressure to 0.3-0.5 MPa to ensure sufficient countercurrent contact and reaction between the two phases. After the extraction reaction is completed, the mixture of oil phase and solvent-rich phase flowing out of the tower is collected. In the above process, the countercurrent contact method significantly increases the contact area and contact time between the solvent and the oil, enhances the extraction effect, efficiently removes inferior components, and improves the basic viscosity index of the oil.
[0031] S300: Place the extraction mixture in a settling tank and allow it to stand and separate into layers. Collect the refined oil phase and the solvent-rich phase separately.
[0032] In this embodiment, the extraction mixture is placed in a settling tank and allowed to stand for stratification, and the refined oil phase and the solvent-rich phase are collected separately. The specific process is as follows: S301: The extracted mixture is transferred to a settling tank, and the temperature inside the tank is kept constant at 70°C; S302: Seal the settling tank and keep it in a static state for 40 minutes, allowing the two phases to naturally separate into layers based on the density difference; S303: Observe the layered interface and confirm that the two phases are completely separated. First, extract the upper refined oil phase, and then collect the lower solvent-rich phase containing impurities to complete the two-phase separation and collection operation.
[0033] In the above process, the extracted mixture is first transported to a settling tank, and the temperature inside the tank is kept constant at 70°C. Then, the settling tank is sealed and kept in a static state for 40 minutes, allowing the two phases to naturally separate by relying on the density difference. After observing the separation interface and confirming that the two phases are completely separated, the upper refined oil phase is first extracted, and then the lower solvent-rich phase containing impurities is collected, completing the separation and collection of the two phases. In the above process, the constant 70°C environment can avoid the two phases from dissolving each other due to temperature changes in the system, and the 40-minute settling time can ensure thorough separation, guarantee the purity of the two materials, and prevent them from being mixed.
[0034] S400: The solvent-rich phase is distilled at atmospheric pressure, stripped with steam, and the recovered solvent is recycled.
[0035] In this embodiment, the solvent-rich phase is subjected to atmospheric distillation, followed by steam stripping to recover the solvent for recycling. The specific process is as follows: S401: The collected solvent-rich phase is fed into an atmospheric distillation apparatus and heated to 150°C; S402: Steam stripping is performed by introducing 4% of the total mass of the solvent-rich phase. The solvent and dissolved impurity components are separated by a combination of distillation and stripping. S403: Collect the purified compound solvent and transport it to the extraction process for recycling.
[0036] In the above process, the collected solvent-rich phase is first sent to an atmospheric distillation apparatus and heated to 150°C; then, steam accounting for 4% of the total mass of the solvent-rich phase is introduced for stripping. The solvent and dissolved impurity components are separated by a combination of distillation and stripping; the purified compound solvent is then collected and sent to the extraction process for recycling. In the above process, steam stripping can effectively reduce the boiling point of the solvent, improve the separation efficiency, further improve the purity of the recovered solvent, and reduce solvent consumption and production costs.
[0037] S500: The refined oil phase is dewaxed using an acetone-benzene-toluene ternary solvent, and the wax paste and dewaxed oil are separated by filtration.
[0038] In this embodiment, the refined oil phase is dewaxed using an acetone-benzene-toluene ternary solvent, and the wax paste and dewaxed oil are separated by filtration. The specific process is as follows: S501: Add acetone-benzene-toluene ternary dewaxing solvent to the refined oil phase and mix thoroughly. Cool the mixture to -28℃ and keep it at a constant temperature. The waxy components in the oil will crystallize out. S502: The cooled material is fed into a filtration device for solid-liquid separation, and the solid wax paste and liquid dewaxing oil are collected to complete the dewaxing process.
[0039] In the above process, acetone-benzene-toluene ternary dewaxing solvent is first added to the refined oil phase and mixed thoroughly. The mixture is then cooled to -28°C and kept at a constant temperature, causing the waxy components in the oil to crystallize and precipitate. The cooled material is then sent to a filtration device for solid-liquid separation, and the solid wax paste and liquid dewaxing oil are collected to complete the dewaxing process. In the above-mentioned low-temperature environment of -28°C, deep dewaxing of the oil can be achieved, maximizing the precipitation of waxy components and effectively reducing the pour point of the lubricating oil base oil.
[0040] S600: Activated clay is added to dewaxed oil, and impurities are removed by filtration to obtain the base oil for finished lubricating oil.
[0041] In this embodiment, activated clay is added to the dewaxed oil, and impurities are removed by filtration to obtain the base oil for the finished lubricating oil. The specific process is as follows: S601: Add 3% by weight of activated clay to the dewaxed oil and stir to mix the materials evenly; S602: Heat the system to 130℃, keep it at the temperature and continue to react for 35 minutes to use activated clay to adsorb residual gum, pigments and trace impurities in the oil. S603: After the reaction is complete, filter to remove waste clay and solid impurities to obtain the finished lubricating oil base oil.
[0042] In the above process, 3% of activated clay by mass is first added to the dewaxed oil, and the mixture is stirred to ensure uniform mixing. Then, the system is heated to 130°C, kept at this temperature, and continuously reacted for 35 minutes. The activated clay adsorbs residual gum, pigments, and trace impurities in the oil. After the reaction is complete, the waste clay and solid impurities are removed by filtration to obtain the finished lubricating oil base oil. The combination of temperature and reaction time ensures that the activated clay can fully exert its adsorption and purification effect, while also preventing the oil from oxidizing and deteriorating due to prolonged high temperatures, thus guaranteeing the overall performance of the product.
[0043] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.
[0044] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.
Claims
1. A solvent-refined process for producing low-pour-point, high-viscosity-index lubricating oil, characterized in that, Includes the following steps: The vacuum distillate fraction is heated to remove free water, light components and mechanical impurities, resulting in a pretreated feedstock. A mixture of furfural and light alkane solvents was fed into a countercurrent extraction tower for extraction, resulting in a mixture of oil phase and solvent-rich phase. The extraction mixture was placed in a settling tank and allowed to stand to separate into layers. The refined oil phase and the solvent-rich phase were collected separately. The solvent-rich phase is distilled under normal pressure, stripped with steam, and the recovered solvent is recycled. The refined oil phase was dewaxed using an acetone-benzene-toluene ternary solvent, and the wax paste and dewaxed oil were separated by filtration. Activated clay is added to the dewaxed oil, and the mixture is filtered to remove impurities to obtain the base oil for the finished lubricating oil.
2. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of heating the vacuum distillate oil to remove free water, light components, and mechanical impurities, resulting in a pretreated feedstock: The reduced pressure distillate oil is transported to the heating equipment, gradually heated to 95°C, and kept at a constant temperature. The free water and small molecule light components contained in the oil are removed by flash evaporation through the heating effect. Filtration removes suspended solid mechanical impurities from oil products; The processed oil was tested for moisture content, and materials with a water content of ≤0.03% were selected as pre-treated feed oil.
3. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of using furfural and light alkane compound solvents to extract the mixture in a countercurrent extraction tower to obtain a mixture of oil phase and solvent-rich phase: A compound extraction solvent was prepared by mixing furfural and light alkanes. The compound solvent and the pretreated raw oil were fed into the countercurrent extraction tower at a volume ratio of 2:
1. The internal temperature of the extraction tower is adjusted to 60–120°C and the pressure to 0.3–0.5 MPa to ensure sufficient countercurrent contact and reaction between the two phases. Once the extraction reaction is complete, collect the mixture of oil phase and solvent-rich phase flowing out of the tower.
4. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of placing the extraction mixture in a settling tank for sedimentation and separating the layers, and separately collecting the refined oil phase and the solvent-rich phase: The extracted mixture is transferred to a settling tank, and the temperature inside the tank is kept constant at 70°C. Seal the settling tank and keep it in a static state for 40 minutes, allowing the two phases to naturally separate into layers based on the density difference. After observing the layered interface and confirming that the two phases are completely separated, the upper refined oil phase is first extracted, and then the lower solvent-rich phase containing impurities is collected to complete the two-phase separation and collection operation.
5. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of distilling the solvent-rich phase under normal pressure, stripping it with steam, and recovering the solvent for recycling: The collected solvent-rich phase was fed into an atmospheric distillation apparatus and heated to 150°C. Steam stripping is performed by introducing 4% of the total mass of the solvent-rich phase with water vapor. The solvent and dissolved impurity components are separated by a combination of distillation and stripping. The purified compound solvent is collected and transported to the extraction process for recycling.
6. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of solvent dewaxing the refined oil phase using an acetone-benzene-toluene ternary solvent and filtering to separate the wax paste and dewaxed oil: Add acetone-benzene-toluene ternary dewaxing solvent to the refined oil phase and mix thoroughly. Cool the mixture to -28°C and keep it at a constant temperature. The waxy components in the oil crystallize out. The cooled material is fed into a filtration device for solid-liquid separation, and the solid wax paste and liquid dewaxing oil are collected to complete the dewaxing process.
7. The solvent-refined low-pour-point, high-viscosity-index lubricating oil production process as described in claim 1, characterized in that, In the step of adding activated clay to dewaxed oil and filtering to remove impurities to obtain the base oil for lubricating oil: Add 3% by weight of activated clay to the dewaxed oil and stir to mix the materials evenly. The system was heated to 130℃, kept at that temperature and continuously reacted for 35 minutes, using activated clay to adsorb residual gum, pigments and trace impurities in the oil. After the reaction is complete, filter to remove waste clay and solid impurities to obtain the finished lubricating oil base oil.