A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration

Abstract

This invention discloses a method for producing Group II base oil from Group I base oil based on the regeneration of waste lubricating oil, belonging to the field of lubricating oil base oil technology. This invention uses Group I base oil obtained from the regeneration of waste lubricating oil as raw material, and obtains Group II base oil through multi-stage adsorption treatment in a primary stirred adsorption reactor, a regenerated clay adsorption reactor, a secondary stirred adsorption reactor, and an activated clay adsorption reactor. In the primary and secondary stirred adsorption reactors, silica gel is used as the adsorbent, which can adsorb colloids, water, aromatic hydrocarbons, some oxygen-containing compounds, and nitrogen-containing compounds in the base oil through physical adsorption and polar interactions. In the regenerated clay adsorption reactor, the heteropolyacid strong acid sites on the modified regenerated clay can undergo acid-base neutralization chemisorption with the alkaline nitrogen-containing compounds in the base oil. Finally, deep adsorption is performed using activated clay in the activated clay adsorption reactor to obtain Group II base oil with low nitrogen content and high oxidation stability. The process is simple and the conditions are mild.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil base oil technology, specifically relating to a method for producing Group II base oil from Group I base oil based on the regeneration of waste lubricating oil. Background Technology

[0002] Lubricating oil deteriorates during mechanical transmission and engine lubrication processes. For example, lubricating oil used in cooling, transmission, and heat treatment systems must be replaced after a period of use when its lubrication and performance indicators decline to a certain level. This replacement process generates large amounts of waste hydraulic oil, gear oil, and contaminated oil used to clean machine parts. This waste lubricating oil is often directly dumped as waste or burned as fuel, resulting in significant resource waste and exacerbating environmental pollution. Analysis of lubricating oil degradation mechanisms reveals that most waste lubricating oil is not truly ineffective; only some of its hydrocarbons deteriorate, primarily low-molecular-weight hydrocarbons, polycyclic aromatic hydrocarbons, gums, or asphalt, accounting for approximately 10%–25%. The majority of the remaining hydrocarbons remain the main active components of the lubricating oil. By removing the deteriorated substances and impurities from waste lubricating oil through physical or chemical methods, it can be regenerated into lubricating oil base oils that meet certain quality requirements.

[0003] The traditional regeneration process for lubricating oil is the sulfuric acid-clay refining process. While simple and requiring relatively low-end equipment, it suffers from significant secondary pollution and low product yield, leading to its gradual replacement by solvent refining technology. Solvent refining of waste lubricating oil yields regenerated base oils that meet Group I base oil requirements. However, as the lubricating oil industry's demands for base oil quality continue to rise, the demand for Group I regenerated base oils is decreasing. Therefore, it is necessary to use Group I regenerated base oils as raw materials to produce Group II base oils. Currently, the hydrorefining method for producing Group II base oils is complex and costly. Furthermore, alkaline nitrogen-containing compounds in the base oil are difficult to remove through hydrogenation, resulting in high nitrogen content and poor oxidation stability in the product. Summary of the Invention

[0004] This invention provides a method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil, which can solve the problem of high nitrogen content in the production of Group II base oils from regenerated Group I base oils in the prior art.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Heat and stir the base oil in a primary stirred adsorption vessel for adsorption. After adsorption, the base oil enters the regenerated clay adsorption vessel. Step 2: Add heteropoly acid-modified regenerated clay to the regenerated clay adsorption vessel, heat and stir for adsorption, and then filter the base oil through a filter. Step 3: The filtered oil enters the secondary stirred adsorption vessel, where it is heated and stirred for adsorption. After adsorption, the base oil enters the activated clay adsorption vessel. Step 4: Add activated clay to the activated clay adsorption vessel, heat and stir to adsorb. After adsorption, the base oil is filtered through a filter press, and the filtered oil is a Group II base oil.

[0006] Furthermore, the base oil is obtained by regenerating waste lubricating oil, with a saturated hydrocarbon content of 88-92 wt%, a basic nitrogen content of 50-200 μg / g, and a sulfur content of 350-1000 μg / g.

[0007] Furthermore, silica gel is used as the adsorbent in both the primary and secondary stirred adsorption vessels, with the silica gel accounting for 3-8% of the mass of the base oil.

[0008] Furthermore, in step 1, the heating and stirring adsorption temperature is 30-50℃, and the duration is 30-100min.

[0009] Furthermore, the preparation steps of the heteropolyacid-modified recycled clay are as follows: S1. The waste bleaching clay from which the oil has been extracted is calcined at high temperature, acidified, washed with water, dried and pulverized to obtain recycled bleaching clay. S2. Prepare a heteropoly acid solution, immerse the regenerated clay in the heteropoly acid solution for 24-72 hours, and dry the immersion solution to obtain heteropoly acid modified regenerated clay.

[0010] After high-temperature calcination and regeneration, the microporous and mesoporous structures of waste clay are generally destroyed, the pore size increases, and the adsorption performance decreases. Heteropolyacid molecular clusters are relatively large. When clay with small pore size is used as a carrier, the heteropolyacid molecular clusters cannot enter the pores and can only be adsorbed on the surface. In the above preparation, high-temperature calcination and regeneration of clay is used as a carrier. On the one hand, it can solve the problem of recycling and utilization of regenerated clay. On the other hand, the large pore size structure of regenerated clay is conducive to the entry of heteropolyacid molecules, increasing the loading of heteropolyacids. Compared with sulfuric acid, heteropolyacids are less corrosive. Loading them on regenerated clay yields modified regenerated clay. The acidic sites of heteropolyacids are uniformly dispersed, which can effectively adsorb alkaline nitrogen-containing compounds in base oil.

[0011] Furthermore, the heteropolyacid solution is one of tungstic acid solution, phosphomolybdic acid solution, and phosphotungstic acid solution; The heteropolyacid concentration of the heteropolyacid solution is 10-20 wt%.

[0012] Furthermore, the mass ratio of the regenerated clay to the heteropolyacid solution is 0.1-0.3:1.

[0013] Furthermore, the heteropolyacid-modified regenerated clay in the regenerated clay adsorption vessel accounts for 5-7% of the mass of the base oil.

[0014] Furthermore, in step 2, the heating and stirring adsorption temperature is 60-90℃, and the duration is 20-40 minutes.

[0015] Furthermore, in step 3, the heating and stirring adsorption temperature is 90-110℃, and the duration is 30-60 minutes.

[0016] Furthermore, the activated clay in the activated clay adsorption vessel comprises 3-4% of the base oil mass.

[0017] Furthermore, in step 4, the heating and stirring adsorption temperature is 60-90℃, and the duration is 20-40 minutes.

[0018] Furthermore, the Group II base oil has a saturated hydrocarbon content >99wt%, a basic nitrogen content of 1-5μg / g, a sulfur content of 50-230μg / g, and a cerbott strength of 29-30.

[0019] The beneficial effects of this invention are: This invention relates to a multi-stage synergistic adsorption process for removing impurities from waste lubricating oil regenerated into Class I base oil. Silica gel is used as the adsorbent in both the primary and secondary stirred adsorption reactors. Silica gel has a large specific surface area and abundant surface silanol groups, which can adsorb colloids, moisture, aromatic hydrocarbons, some oxygen-containing compounds, and nitrogen-containing compounds in the base oil through physical adsorption and polar interactions. The primary treatment of the base oil is achieved by stirring and adsorption in the primary stirred adsorption reactor, reducing the burden on the subsequent main adsorption process. After primary treatment, the base oil enters a regenerated clay adsorption reactor for adsorption treatment. The strongly acidic sites of heteropolyacids on the modified regenerated clay can undergo acid-base neutralization chemisorption with the basic nitrogen-containing compounds in the base oil. Compared with the physical adsorption of ordinary clay or silica gel, the adsorption and removal of basic nitrogen-containing compounds is enhanced. After the basic nitrogen-containing compounds are removed by the modified regenerated clay, a secondary stirring adsorption process is performed to remove the small amount of residual heteropolyacid substances in the base oil after the stirring adsorption of the modified regenerated clay. Finally, the base oil undergoes deep adsorption with activated clay in an activated clay adsorption reactor to remove residual trace impurities and polycyclic aromatic hydrocarbons, ensuring that a Group II base oil with low nitrogen content and high oxidation stability is obtained. This invention uses Group I base oil regenerated from waste lubricating oil as raw material to produce Group II base oil. The process is simple, the conditions are mild, the production cost is low, and the waste clay is recycled. While improving the quality of the base oil, it also makes rational use of solid waste and saves resources. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1

[0022] Preparation of heteropolyacid-modified recycled clay: S1. The waste bleaching clay from the leaching oil is calcined at 500℃ for 80 minutes, cooled, and then acidified with concentrated sulfuric acid for 1 hour. The volume ratio of bleaching clay to concentrated sulfuric acid is 1:2. The clay is washed with water until the pH is about 5.5, dried, and pulverized to obtain regenerated bleaching clay.

[0023] S2. Prepare a 15% phosphotungstic acid solution, and impregnate the regenerated clay in the heteropoly acid solution at a mass ratio of 0.2:1. Impregnate for 36 hours, and dry the impregnation solution at 100°C to obtain heteropoly acid modified regenerated clay.

[0024] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the regenerated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0025] Step 2: Add heteropolyacid-modified regenerated clay to the regenerated clay adsorption vessel. The heteropolyacid-modified regenerated clay accounts for 6% of the base oil mass. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter.

[0026] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0027] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3.5% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 2μg / g, the sulfur content is 128μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 260min.

[0028] Example 2

[0029] The only difference from Example 1 is that in step 2, the heteropolyacid modified regenerated clay accounts for 5% of the base oil mass.

[0030] The steps and conditions for preparing heteropolyacid-modified regenerated clay are the same as in Example 1.

[0031] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the regenerated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0032] Step 2: Add heteropolyacid-modified regenerated clay to the regenerated clay adsorption vessel. The heteropolyacid-modified regenerated clay is 5% of the base oil mass. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered by a filter.

[0033] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0034] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3.5% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 5μg / g, the sulfur content is 135μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 225min.

[0035] Example 3

[0036] The only difference from Example 1 is that in step 2, the heteropolyacid modified regenerated clay accounts for 7% of the base oil mass.

[0037] The steps and conditions for preparing heteropolyacid-modified regenerated clay are the same as in Example 1.

[0038] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the regenerated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0039] Step 2: Add heteropolyacid-modified regenerated clay to the regenerated clay adsorption vessel. The heteropolyacid-modified regenerated clay accounts for 7% of the base oil mass. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter.

[0040] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0041] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3.5% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 2μg / g, the sulfur content is 132μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 280min.

[0042] Example 4

[0043] The only difference from Example 1 is that in step 4, the activated clay is 3% of the base oil mass.

[0044] The steps and conditions for preparing heteropolyacid-modified regenerated clay are the same as in Example 1.

[0045] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the regenerated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0046] Step 2: Add heteropolyacid-modified regenerated clay to the regenerated clay adsorption vessel. The heteropolyacid-modified regenerated clay accounts for 6% of the base oil mass. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter.

[0047] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0048] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 3μg / g, the sulfur content is 122μg / g, the cerbottleneck strength is 29, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 255min.

[0049] Example 5

[0050] The only difference from Example 1 is that in step 4, the activated clay accounts for 4% of the mass of the base oil.

[0051] The steps and conditions for preparing heteropolyacid-modified regenerated clay are the same as in Example 1.

[0052] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the regenerated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0053] Step 2: Add heteropolyacid-modified regenerated clay to the regenerated clay adsorption vessel. The heteropolyacid-modified regenerated clay accounts for 6% of the base oil mass. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter.

[0054] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0055] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 1μg / g, the sulfur content is 136μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 290min.

[0056] Comparative Example 1

[0057] Group I base oils based on waste lubricating oil regeneration are used to produce Group II base oils through a hydrorefining process, including the following steps: The regenerated base oil from waste lubricating oil is added to a hydrorefining reactor for hydrotreating, with the temperature set at 330℃, the pressure at 6MPa, and the space velocity at 1.2h. -1 The hydrogen-to-oil ratio was 600. The hydrorefining reactor used RL-1 lubricating oil hydrotreating catalyst. The performance indicators of the Group I base oil regenerated from the waste lubricating oil were as follows: saturated hydrocarbon content 89 wt%, basic nitrogen content 189 μg / g, and sulfur content 650 μg / g. After hydrotreating, Group II base oil was obtained. The performance indicators of the Group II base oil were as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 16μg / g, the sulfur content is 215μg / g, the cerbottleneck strength is 28, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 200min.

[0058] Comparative Example 2

[0059] The only difference from Example 1 is that this comparative example uses activated clay loaded with heteropoly acids instead of recycled clay.

[0060] Preparation of heteropolyacid-modified clay: A 15% phosphotungstic acid solution was prepared, and activated clay was impregnated in the heteropoly acid solution at a mass ratio of 0.2:1. The impregnation was carried out for 36 hours, and the impregnation solution was dried at 100°C to obtain heteropoly acid modified clay.

[0061] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to a primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters a modified clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0062] Step 2: Add heteropolyacid modified clay to the modified clay adsorption vessel. The heteropolyacid modified clay is 6% of the mass of the base oil. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered by a filter.

[0063] Step 3: Filter the oil and put it into a two-stage stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil is put into an activated clay adsorption vessel.

[0064] Step 4: Add activated clay to the activated clay adsorption vessel. The activated clay content is 3.5% of the base oil mass. Heat to 70℃ and stir for 30 minutes for adsorption. After adsorption, filter the base oil through a filter press. The filtered oil is a Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 9μg / g, the sulfur content is 141μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 215min.

[0065] Comparative Example 3

[0066] The only difference from Example 1 is that this comparative example uses activated clay instead of heteropolyacid-modified regenerated clay.

[0067] A method for producing Group II base oils from Group I base oils based on waste lubricating oil regeneration includes the following steps: Step 1: Add the regenerated base oil from waste lubricating oil to the primary stirred adsorption vessel. Add silica gel to the primary stirred adsorption vessel at 5% of the base oil mass. Heat the primary stirred adsorption vessel to 40℃ and stir for 60 minutes. After adsorption, the base oil enters the primary activated clay adsorption vessel. The performance indicators of the regenerated base oil from waste lubricating oil are as follows: saturated hydrocarbon content is 89wt%, basic nitrogen content is 189μg / g, and sulfur content is 650μg / g.

[0068] Step 2: Add activated clay to the primary activated clay adsorption vessel. The activated clay is 6% of the mass of the base oil. Heat to 80℃ and stir for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter.

[0069] Step 3: Filter the oil and put it into the secondary stirred adsorption vessel. Add silica gel at 5% of the mass of the base oil. Heat to 110℃ and stir for 40 minutes for adsorption. After adsorption, the base oil enters the secondary activated clay adsorption vessel.

[0070] Step 4: Activated clay is added to the secondary activated clay adsorption vessel at a concentration of 3.5% of the base oil mass. The temperature is raised to 70℃ and the mixture is stirred for 30 minutes for adsorption. After adsorption, the base oil is filtered through a filter press. The filtered oil is classified as Group II base oil. The performance indicators of the Group II base oil are as follows: The saturated hydrocarbon content is >99wt%, the basic nitrogen content is 12μg / g, the sulfur content is 156μg / g, the cerbottleneck strength is 30, and the oxidation induction period determined by the rotating oxygen bomb method at 150℃ is 210min.

[0071] As can be seen from the results of the examples and comparative examples, the multi-stage adsorption process used in the embodiments of the present invention is milder and has lower equipment requirements than the conventional hydrorefining process. The Group I base oil regenerated from waste lubricating oil meets the requirements of Group II base oil in all aspects after treatment, and the alkaline nitrogen content can be as low as 1 μg / g. The resulting Group II base oil has good oxidation stability.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0073] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil, characterized in that, Includes the following steps: Step 1: Heat and stir the base oil in a primary stirred adsorption vessel for adsorption. After adsorption, the base oil enters the regenerated clay adsorption vessel. Step 2: Modified recycled clay is added to the recycled clay adsorption vessel, heated and stirred for adsorption, and the base oil after adsorption is filtered by a filter. Step 3: The filtered oil enters the secondary stirred adsorption vessel, where it is heated and stirred for adsorption. After adsorption, the base oil enters the activated clay adsorption vessel. Step 4: Add activated clay to the activated clay adsorption vessel, heat and stir to adsorb. After adsorption, the base oil is filtered through a filter press, and the filtered oil is a Group II base oil.

2. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, The aforementioned base oil is obtained by regenerating waste lubricating oil, with a saturated hydrocarbon content of 88-92 wt%, an alkaline nitrogen content of 50-200 μg / g, and a sulfur content of 350-1000 μg / g.

3. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, Both the primary and secondary stirred adsorption reactors use silica gel as the adsorbent, with silica gel comprising 3-8% of the base oil mass.

4. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, In step 1, the heating and stirring adsorption temperature is 30-50℃, and the duration is 30-100min.

5. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, The preparation steps of the modified recycled clay are as follows: S1. The waste bleaching clay from which the oil has been extracted is calcined at high temperature, acidified, washed with water, dried and pulverized to obtain recycled bleaching clay. S2. Prepare a heteropoly acid solution, immerse the recycled clay in the heteropoly acid solution for 24-72 hours, and dry the immersion solution to obtain modified recycled clay.

6. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 5, characterized in that, The heteropolyacid solution is one of tungstic acid solution, phosphomolybdic acid solution and phosphotungstic acid solution; The heteropolyacid concentration of the heteropolyacid solution is 10-20 wt%. The mass ratio of the regenerated clay to the heteropolyacid solution is 0.1-0.3:

1.

7. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, The modified recycled clay in the recycled clay adsorption reactor accounts for 5-7% of the base oil mass; In step 2, the heating and stirring adsorption temperature is 60-90℃, and the duration is 20-40 minutes.

8. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, In step 3, the heating and stirring adsorption temperature is 90-110℃, and the duration is 30-60 minutes.

9. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, The activated clay in the activated clay adsorption vessel is 3-4% of the base oil mass. In step 4, the heating and stirring adsorption temperature is 60-90℃, and the duration is 20-40 minutes.

10. The method for producing Group II base oils from Group I base oils based on the regeneration of waste lubricating oil according to claim 1, characterized in that, The Group II base oil has a saturated hydrocarbon content >99wt%, a basic nitrogen content of 5-20μg / g, a sulfur content of 50-230μg / g, and a cerbott strength of 29-30.