Method of producing lubricating base oil and lubricating base oil produced thereby

Abstract

To provide a method of producing a lubricating base oil and a lubricating base oil produced thereby.SOLUTION: The method includes: providing a waste lubricating oil-derived purification fraction, in which the waste lubricating oil-derived purification fraction is derived from a lubricating oil containing a lubricating base oil of API Group I or II, and the waste lubricating oil -derived purification fraction contains a vacuum ionic refined oil, a first regenerated base oil, or a combination thereof; a dewaxing step of dewaxing the waste lubricating oil-derived purification fraction to produce a second regenerated base oil; and a blending step of blending the second regenerated base oil with a separate lubricating base oil to produce a lubricating base oil mixture of Group III or higher. The method has an economical advantage in that a low-quality waste lubricating oil can be used as a feedstock for the manufacturing process of a higher quality lubricating base oil, and also has an environmentally friendly advantage in that a waste lubricating oil is recycled as a feedstock for the manufacturing process of high-grade lubricating base oil.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a lubricant base oil and the lubricant base oil produced thereby. [Background technology]

[0002] Waste lubricating oil goes through a series of refining processes and is entirely used as fuel oil in Japan, while part of it is used as fuel oil and another part is used as low-grade recycled base oil overseas.

[0003] On the other hand, generally speaking, a good lubricant base oil has a high viscosity index, excellent stability (oxidation, heat, UV, etc.), and low volatility. The American Petroleum Institute (API) classifies lubricant base oils according to their quality as shown in Table 1 below.

[0004] [Table 1]

[0005] In the above classification, the quality of lubricant base oil is evaluated as being superior from Group I to Group V, and among them, Group III lubricant base oil is generally produced by advanced hydrocracking reaction. Unconverted oil, which is a heavy fraction that is not converted to fuel oil in the fuel oil hydrocracking process, is usually used as a feedstock for producing high-grade lubricant base oil of Group III or higher. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Publication No. 2021-0002682 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure aims to provide a method for producing a lubricant base oil and the lubricant base oil produced thereby. [Means for solving the problem]

[0008] According to a first aspect of the disclosure, there is provided a method for producing a lubricant base oil blend, the method comprising the steps of providing a refined fraction derived from a used lubricant, the refined fraction derived from the used lubricant being derived from a lubricant comprising a lubricant base oil below API Group III, the refined fraction derived from the used lubricant comprising an API refined oil, a first reclaimed base oil, or a combination thereof; dewaxing the refined fraction derived from the used lubricant to form a second reclaimed base oil; and blending the second reclaimed base oil with a separate lubricant base oil to form a Group III or higher lubricant base oil blend.

[0009] According to one embodiment, the refined fraction derived from the used lubricating oil may have a sulfur content of 200 ppm to 3000 ppm, a nitrogen content of 100 ppm to 1200 ppm, and a kinematic viscosity at 100° C. of 4 to 11 cSt.

[0010] According to one embodiment, the dewaxing step can include hydrotreating, hydrodewaxing, and hydrofinishing the refinery fraction derived from the used lube oil.

[0011] According to one embodiment, the hydrodewaxing step is carried out in the presence of a catalyst comprising at least one of an EU-2 zeolite support, an alumina and a silica-alumina support, at a temperature of 300° C. to 350° C. and at a pressure of 60 kg / cm 2 More than 150kg / cm 2 It can be carried out at the following pressures:

[0012] According to one embodiment, the catalyst may include Co, Ni, Pt, Pd, Mo, W, or a combination thereof as a metal active component.

[0013] According to one embodiment, the separate lubricant base oil may have a kinematic viscosity at 100° C. of 6 to 7 cSt, a viscosity index of 120 or more, a pour point of -10° C. or less, and a CCS (Cold Crank Simulator) viscosity at -30° C. of 5400 cP or less.

[0014] According to one embodiment, the amount of the second recycled base oil blended in the blending step can be 1 to 30 volume % of the Group III or higher lubricant base oil mixture.

[0015] According to a second aspect of the present disclosure, there is provided a lubricant base oil mixture comprising the second recycled base oil described above.

[0016] According to one embodiment, the lubricant base oil blend containing the second recycled base oil may have a viscosity index of 120 or greater and a saturation level of 90% or greater. Effect of the Invention

[0017] According to the present disclosure, low-quality waste lubricating oil can be used as a feedstock for the production process of higher-quality lubricating base oil, which is advantageous from an economic perspective, and also advantageous from the perspective of environmental harmony, as the waste lubricating oil can be recycled instead of being discarded. [Brief description of the drawings]

[0018] [Figure 1] 1 is a process schematic diagram according to one embodiment. [Diagram 2] 1 is a process schematic diagram according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The objects, advantages and features of the present disclosure will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings, but the present disclosure is not necessarily limited thereto. In addition, in describing the present disclosure, if it is determined that a specific description of related known technology may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted.

[0020] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0021] According to a first aspect of the present disclosure, there is provided a method for producing a lubricant base oil blend, the method comprising the steps of: providing a refined fraction derived from a used lubricant; the refined fraction derived from the used lubricant is derived from a lubricant containing a lubricant base oil below API Group III; the refined fraction derived from the used lubricant includes a vacuum iron refined oil, a first reclaimed base oil, or a combination thereof; dewaxing the refined fraction derived from the used lubricant to produce a second reclaimed base oil; and blending the second reclaimed base oil with another lubricant base oil to produce a Group III or higher lubricant base oil blend. The method for producing the lubricant base oil blend is generally as shown in FIG. 1.

[0022] The refined fraction derived from the waste lubricating oil is derived from a lubricating oil containing a lubricating base oil having properties that belong to Group III or less of the American Petroleum Institute (API) lubricating base oil classification, more specifically, derived from waste lubricating oil generated after the use of a lubricating oil containing a lubricating base oil having properties that belong to Group III or less. Specifically, the lubricating base oil having properties that belong to Group III or less includes a sulfur content of 300 ppm or more, a saturation degree of less than 90%, a viscosity index of 120 or less, or a combination thereof. Generally, various additives are added to the lubricating base oil in the lubricating oil, but the additives contain a large amount of impurities that are not suitable for use as a lubricating base oil, so the refined fraction derived from the waste lubricating oil can also contain a large amount of impurities. For example, the waste lubricating oil containing a lubricating base oil having properties that belong to Group III or less can contain 1000 to 3000 ppm of sulfur, 500 to 2000 ppm of nitrogen, 100 to 2000 ppm of chlorine, and other metal impurities that can flow into the lubricating action.

[0023] In one embodiment, the step of providing the refined fraction derived from the used lubricant oil can include centrifuging the used lubricant oil, distilling it at atmospheric pressure, distilling it under reduced pressure, or a combination thereof. The steps correspond to steps of reducing the content of sulfur, nitrogen, chlorine, and metal impurities present in the fraction derived from the used lubricant oil. The term "refined fraction derived from the used lubricant oil" as used in this disclosure refers to a fraction obtained after the fraction derived from the used lubricant oil is introduced into a refining step, and has a reduced impurity content compared to the used lubricant oil.

[0024] The step of providing a refined fraction derived from the used lubricating oil may preferably include a step of centrifuging the used lubricating oil containing the lubricating base oil below Group III, a step of vacuum distillation, and a step of atmospheric distillation, and more preferably, the steps of centrifugation, atmospheric distillation, and vacuum distillation may be performed in this order.

[0025] The centrifugation step is for separating and removing impurities present in the waste lubricating oil, and may be performed at a rotation speed of about 100 rpm to 3000 rpm. Instead of the centrifugation, impurities may be precipitated by natural precipitation, but centrifugation is more preferable in terms of separation speed and performance. The centrifugation step may also involve the introduction of a flocculant, in which case the impurities flocculated by the introduction of the flocculant are separated and removed by rotation. There is no limitation on the flocculant as long as it enables the flocculation of impurities, and as a non-limiting example, ammonium phosphate can be used as the flocculant. In one embodiment, the centrifugation step may be performed at 80 to 120 ° C, and separation of the flocculants can be smoothly performed within this temperature range.

[0026] In one embodiment, the waste lubricating oil after the solid phase impurities that are not mixed with the waste lubricating oil and have high density are primarily removed by centrifugation is introduced into atmospheric distillation under atmospheric pressure. Atmospheric distillation is carried out at a temperature of about 50°C to 350°C, and as the atmospheric distillation temperature increases, the fractions in the waste lubricating oil are distilled and separated in ascending order of boiling point. Among the fractions separated in the atmospheric distillation step, fractions having a boiling point of about 150°C or higher are collected to generate refined fractions. In this way, the fraction derived from the waste lubricating oil after undergoing centrifugation and atmospheric distillation may be called "ion refined oil".

[0027] In one embodiment, the fraction collected in the atmospheric distillation step is subsequently introduced into the vacuum distillation. This is for more detailed fractionation of the fraction obtained in the atmospheric distillation step, and is carried out under reduced pressure and mild temperature conditions because cracking of the fraction may occur if the distillation temperature is increased for detailed fractionation of the fraction under atmospheric pressure. The vacuum distillation may be carried out at a pressure of 10 torr or less and at a temperature of 150 to 350°C. During the vacuum distillation step, a fraction having a boiling point of 300 to 550°C is collected, which is called "reduced pressure ion refined oil". The reduced pressure ion refined oil may have a specific gravity of about 0.8 to 1.0, a viscosity index (VI) of about 80 to 150, and a pour point of about -20°C to 0°C. The reduced pressure ion refined oil may also have a reduced impurity content compared to the waste lubricating oil. The reduced pressure ion refined oil has a color close to brown, about 5 to 6 based on ASTM standard, and by the centrifugation and two-step distillation, the reduced pressure ion refined oil can have a sediment and water content that is reduced compared to the sediment and water content that were present in the waste lubricating oil before refining.

[0028] In one embodiment, the reduced pressure ion refined oil may have a sulfur content of from 200 ppm to 3000 ppm, a nitrogen content of from 100 ppm to 1200 ppm, and a kinematic viscosity at 100° C. of from 4 to 11 cSt.

[0029] In one embodiment, the step of providing the refined fraction derived from the waste lubricating oil may include a solvent extraction or a first hydrogenation step. The solvent extraction of the fraction derived from the waste lubricating oil is a step of mixing the fraction derived from the waste lubricating oil and the solvent in a mixing tank, and then allowing the mixture to stand to separate into phases, thereby obtaining a phase in which the fraction to be obtained is the main component, and removing a phase containing a large amount of impurities. The solvent used for the solvent extraction is a solvent that has a higher affinity for impurities than the oil components in the fraction derived from the waste lubricating oil, and the main solvents used are N-methyl-2-pyrrolidone (NMP), sulfolane, DMSO, furfural, phenol, and acetone. The solvent has a high affinity for impurities and a low affinity for the fraction derived from the waste lubricating oil, so it can be used without any restrictions as long as it is phase-separated from the fraction derived from the waste lubricating oil and has a difference in volatility for subsequent solvent separation.

[0030] The solvent extraction of the fraction derived from the waste lubricating oil is carried out at a temperature of about 30 to 200°C, preferably about 30 to 150°C, more preferably about 40 to 120°C, and at atmospheric pressure of 20 kg / cm 2 , preferably atmospheric pressure to 15 kg / cm 2 , more preferably atmospheric pressure to 10 kg / cm 2 The reaction can be carried out under pressure.

[0031] In addition, the volume ratio of the solvent used in the solvent extraction step of the fraction derived from the waste lubricating oil to the oil component in the refined fraction can be 1:1 to 6:1, preferably 1:1 to 5:1, 1:1 to 4:1, 1:1 to 3:1, 1:1 to 2:1, 2:1 to 5:1, 2:1 to 4:1, 2:1 to 3:1, 3:1 to 5:1, 3:1 to 4:1, and 4:1 to 5:1. More preferably, the volume ratio can be 1.5:1 to 3:1. The volume ratio is preferable from the viewpoint of the balance between the level of removal of impurities by solvent extraction and the yield of lubricating base oil produced from the refined fraction derived from the waste lubricating oil thereafter.

[0032] The first hydrogenation treatment of the fraction derived from the used lubricating oil is a step in which the fraction derived from the used lubricating oil is hydrogenated at high temperature and pressure in the presence of a catalyst to remove sulfur, nitrogen, chlorine and other metal impurities contained in the fraction derived from the used lubricating oil and to saturate unsaturated hydrocarbons present in the fraction derived from the used lubricating oil.

[0033] The first hydrogenation treatment may be carried out in the presence of a catalyst, such as Ni-Mo catalyst, Co-Mo catalyst, Raney nickel, Raney cobalt, platinum catalyst, etc., but is not limited thereto, and any hydrogenation catalyst having an effect on hydrogen saturation reaction and impurity removal may be used without limitation.

[0034] The first hydrogenation treatment is carried out under the following conditions: temperature of about 200 to 500°C, preferably about 250 to 450°C, more preferably about 300 to 400°C, and pressure of 50 kg / cm 2 ~300kg / cm 2 , preferably 50kg / cm 2 ~250kg / cm 2 , more preferably 100 kg / cm 2 ~200kg / cm 2 Pressure conditions: 0.1~5.0hr -1 , preferably 0.3 to 4.0 hours -1 , more preferably 0.5 to 3.0 hr -1 Liquid hourly space velocity (LHSV) conditions and 300 to 3000 Nm 3 / m 3 , preferably 500 to 2500 Nm 3 / m 3 , more preferably 1000 to 2000 Nm 3 / m 3The dewaxing process may be carried out under the condition of a volume ratio of hydrogen to the refined fraction of 1000 to 10000. The above conditions are within a range that does not affect the subsequent life of the dewaxing catalyst, and under the above conditions, it is possible to achieve a minimum level of removal of impurities such as sulfur and nitrogen present in the fraction derived from the used lubricant oil and a minimum yield loss of the final product, the lubricant base oil. As described above, the refined fraction derived from the used lubricant oil obtained by introducing the fraction derived from the used lubricant oil into a refining step including solvent extraction or first hydrogenation treatment is called "first regenerated base oil".

[0035] In one embodiment, the first recycled base oil may contain a sulfur content of 100 to 3000 ppm, a nitrogen content of 100 to 1000 ppm, and a chlorine content of 5 to 200 ppm. The first recycled base oil may have a boiling point of 350 to 550°C, more preferably 420 to 520°C, and therefore may have a narrower boiling point range than ion-refined oil.

[0036] The refined fraction derived from the waste lubricating oil includes the above-mentioned vacuum refined oil, the first reclaimed base oil, or a combination thereof.

[0037] In one embodiment, the refined fraction derived from the used lubricating oil may comprise a sulfur content of from 200 ppm to 3000 ppm, a nitrogen content of from 100 ppm to 1200 ppm, and a kinematic viscosity at 100° C. of from 4 to 11 cSt.

[0038] The method includes a dewaxing step of dewaxing the refined fraction derived from the used lubricating oil to produce a second recycled base oil. Here, the "second recycled base oil" refers to the refined fraction derived from the used lubricating oil that has been dewaxed in the dewaxing step. The dewaxing step selectively isomerizes the wax components contained in the refined fraction derived from the used lubricating oil to improve low-temperature properties (ensuring a low pour point) and to maintain a high viscosity index (VI). The present disclosure aims to achieve improved efficiency and yield through the improvement of the catalyst used in the dewaxing step. The dewaxing step can include hydrotreating, hydrodewaxing, and subsequent hydrofinishing reactions.

[0039] Prior to hydrodewaxing, a second hydrotreatment can be carried out to remove impurities remaining in the refined fraction derived from the used lubricating oil, and the process conditions and catalyst used in the second hydrotreatment can be the same as those in the first hydrotreatment.

[0040] In one embodiment, the hydrodewaxing step is carried out in the presence of a catalyst comprising an EU-2 zeolite support, at a temperature of 300° C. to 350° C. and at 50 kg / cm 2 More than 150kg / cm 2 More specifically, the hydrodewaxing step can be carried out at a temperature of 310° C. to 340° C., preferably 320° C. to 330° C., at a pressure of 60 kg / cm 2 More than 140kg / cm 2 Pressure below 60kg / cm 2 More than 130kg / cm 2 It can be carried out at the following pressures:

[0041] The subsequent hydrofinishing may be carried out at a process temperature of 200-250° C., except that the catalyst used and the remaining process conditions may be the same as in the hydrodewaxing step.

[0042] In general, the main reaction of catalytic dewaxing is to convert N-paraffins to isoparaffins for improving low-temperature properties through isomerization, and it has been reported that the catalysts used here are mainly bifunctional catalysts. Bifunctional catalysts are composed of two active components: a metal active component (Metal Site) for hydrogenation / dehydrogenation reactions and a support (Acid Site) having an acid site for skeletal isomerization via carbenium ions, while zeolite-structured catalysts are generally composed of an aluminosilicate support and one or more metals selected from Group 8 metals and Group 6 metals.

[0043] The dewaxing catalyst of the present disclosure may include a carrier having an acid site selected from molecular sieves, alumina, and silica-alumina. The carrier having an acid site may include molecular sieves, alumina, silica-alumina, etc., among which molecular sieves refer to crystalline aluminosilicates (zeolites), SAPO, ALPO, etc., and medium pore molecular sieves (SAPO-11, SAPO-41, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48, etc.) having a 10-membered oxygen ring and large pore molecular sieves having a 12-membered oxygen ring may be used.

[0044] In particular, in the present disclosure, EU-2 zeolite with a controlled degree of phase transition may be preferably used as a carrier. If the synthesis conditions are changed after a pure zeolite is produced, or if the synthesis is continued for a certain period of time even under the same hydrothermal synthesis conditions, the synthesized zeolite crystals may gradually undergo phase transformation to a more stable phase. This phenomenon is called zeolite phase transformation, and it has been confirmed that the isomerization selectivity is improved according to the degree of phase transformation of the zeolite, and that the catalyst dewaxing reaction using the zeolite can also exhibit excellent performance.

[0045] In one embodiment, the catalyst may contain Co, Ni, Pt, Pd, Mo, W, or a combination thereof as a metal active component. The catalyst may contain one or more metals having hydrogenation functions selected from elements of Groups 2, 6, 9, and 10 of the periodic table together with the above-mentioned support, and from the viewpoint of hydrogenation / dehydrogenation performance, Co, Ni, Pt, and Pd are particularly preferred among the Groups 9 and 10 (i.e., Group VIII) metals, and Mo and W are preferred among the Group 6 (i.e., Group VIB) metals.

[0046] The second recycled base oil produced in the presence of the above-mentioned catalyst has a sulfur content of less than 5 ppm, a nitrogen content of less than 1 ppm, and a viscosity index of 100 to 120, and therefore has properties similar to Group III lubricant base oil. In one embodiment, if the second recycled base oil produced in the dewaxing step has an impurity content higher than the sulfur and nitrogen contents, it can be introduced into additional hydrotreating for the removal of impurities after the dewaxing step.

[0047] The method includes blending the second recycled base oil with a separate lubricant base oil to produce a lubricant base oil mixture of Group III or higher. Here, the lubricant base oil mixture of Group III or higher refers to a lubricant base oil mixture having properties corresponding to Group III in Table 1, or having a lower sulfur content, a higher saturation level, a higher viscosity index, or a combination thereof than the Group III lubricant base oil conditions. As described above, the second recycled base oil has properties close to Group III lubricant base oil, so that when blended in a certain amount with a separate lubricant base oil of Group III or higher grade, the lubricant base oil mixture as the final product can be a lubricant base oil of Group III or higher. That is, the method uses a fraction derived from waste lubricant oil containing a lubricant base oil below Group III as a feedstock for producing a lubricant base oil of Group III or higher, thereby reducing the production cost of the lubricant base oil of Group III or higher.

[0048] In one embodiment, the separate lubricant base oil may have a kinematic viscosity at 100° C. of 6 to 7 cSt, a viscosity index of 120 or greater, a pour point of −10° C. or less, and a CCS (Cold Crank Simulator) viscosity of 5400 cP or less at −30° C. The separate lubricant base oil may also have a sulfur, nitrogen, and chlorine content of less than 1 ppm.

[0049] In one embodiment, the amount of the second recycled base oil blended in the blending step can be 1 to 30% by volume of the lubricant base oil mixture of Group III or higher. If the amount of the second recycled base oil blended in the blending step is less than 1% by volume of the lubricant base oil mixture of Group III or higher, the proportion of the second recycled base oil in the lubricant base oil mixture of Group III or higher as the final product is low, so the production cost reduction effect may not be large, and if the amount of the second recycled base oil blended in the blending step is less than 1% by volume of the lubricant base oil mixture of Group III or higher, the lubricant base oil mixture of the final product may not have the properties of Group III or higher. In one embodiment, the amount of the second recycled base oil blended in the blending step can be preferably 5 to 25% by volume, more preferably 10 to 20% by volume, of the lubricant base oil mixture of Group III or higher.

[0050] According to a second aspect of the present disclosure, there is provided a method for producing a lubricant base oil blend, comprising blending a lubricant base oil other than the first recycled base oil, and subsequent hydrodewaxing and hydrofinishing steps. The method can be carried out as shown in FIG. 2. The first recycled base oil and the other lubricant base oil of the method have the same properties as the first recycled base oil and the other lubricant base oil of the first aspect, and the blending amount and the process conditions of the hydrodewaxing and hydrofinishing steps can also be the same as those of the first aspect. According to this method, a lubricant base oil blend of Group III or higher can be obtained.

[0051] According to a third aspect of the present disclosure, a lubricant base oil mixture containing the second recycled base oil is provided. As described above, the second recycled base oil corresponds to a dewaxed refined fraction derived from a waste lubricant containing a lubricant base oil below Group III, and the lubricant base oil mixture containing the second recycled base oil can maintain the properties of the following Group III lubricant base oil while containing a fraction derived from a waste lubricant. That is, the lubricant base oil mixture containing the second recycled base oil according to one aspect of the present disclosure is advantageous in terms of economy because a fraction derived from a lower lubricant base oil can be utilized as a component of a higher lubricant base oil, and is also advantageous in terms of environmental harmony in that the amount of oil to be discarded can be reduced by recycling the waste lubricant as a feedstock for a high-grade lubricant base oil manufacturing process instead of discarding it.

[0052] In one embodiment, the lubricant base oil blend containing the second recycled base oil can have a viscosity index greater than 120 and a saturation level of 90% or greater. That is, the lubricant base oil blend containing the second recycled base oil can have a viscosity index and saturation level of the Group III lubricant base oil in Table 1. In one embodiment, the lubricant base oil blend containing the second recycled base oil can have a viscosity index of preferably 125 or greater, more preferably a viscosity index of 130 or greater. The lubricant base oil blend containing the second recycled base oil can also have a saturation level of preferably 95% or greater, more preferably 99% or greater.

[0053] In one embodiment, the lubricant base oil blend containing the second recycled base oil can have a sulfur content, a nitrogen content, and a chlorine content each of less than 1 ppm, i.e., the lubricant base oil blend containing the second recycled base oil can be substantially free of impurities, in addition to meeting the impurity content requirements of Group III lubricant base oils.

[0054] In one embodiment, the lubricant base oil blend containing the second recycled base oil may have a Saybolt Color value of 27 or more. When the Saybolt Color value is 27 or more, it is treated as a lubricant base oil having stability of Water White grade. Water White grade lubricant base oil has a sulfur content and nitrogen content of less than 1 ppm, a saturation level of 99% or more, and an aromatic content of less than 1%, and corresponds to a lubricant base oil that is more stable than a normal API Group III lubricant base oil.

[0055] In one embodiment, the lubricant base oil mixture containing the second recycled base oil can exhibit a UV260-350nm absorbance of 2.5 or less and a UV325nm absorbance of 0.7 or less, as measured by ASTM D2008. Here, the absorbance at wavelengths of 260-350nm indicates that the mixture contains components having 3 or more aromatic rings, and the absorbance at wavelengths of 325nm indicates that the mixture contains components having 3-7 aromatic rings. However, since the lubricant base oil mixture containing the second recycled base oil has low absorbance at these wavelengths, it has a low aromatic content and therefore high stability.

[0056] Preferred examples are presented below to aid in understanding the present disclosure. However, the following examples are provided merely to facilitate understanding of the present disclosure, and the present disclosure is not limited thereto.

[0057] Working Example Measurement of the properties and characteristics of lubricant base oils produced by the disclosed method Waste lubricating oil having a sulfur content of about 2000 ppm, a nitrogen content of about 1500 ppm, and a chlorine content of about 1500 ppm was centrifuged at a speed of about 300 rpm, and the resulting oil was distilled under normal pressure and reduced pressure to obtain a reduced pressure ion refined oil. The reduced pressure ion refined oil obtained by the reduced pressure distillation under the following process conditions contained a heavy fraction having a boiling point of 400°C or more and 550°C or less.

[0058] Here, the atmospheric distillation is carried out at a temperature of 50° C. to 350° C. under atmospheric pressure, and the process conditions of the reduced pressure distillation are as shown in Table 2 below.

[0059] [Table 2]

[0060] On the other hand, a separate waste lubricant containing the same impurity content as the above waste lubricant was mixed at a temperature of about 300°C and a pressure of about 60 to 150 kg / cm 2 Pressure condition, about 3.0 hours -1 The first reclaimed base oil was obtained by hydrotreating the oil under conditions of a liquid hourly space velocity (LHSV) of about 1000 and a volume ratio of hydrogen to the fraction derived from the waste lubricating oil of about 1000. The refined fraction derived from the waste lubricating oil, which was a mixture of the reduced pressure ion refined oil and the first reclaimed base oil in a volume ratio of 1:1, was hydrodewaxed. Hydrodewaxing was performed at a temperature of about 350°C and a pressure of about 150 kg / cm 2 The subsequent hydrofinishing was carried out in the presence of a hydrogenation catalyst containing EU-2 zeolite as a support and Ni as the metal active component at a temperature of about 230°C and a pressure of about 60-150 kg / cm3 in the presence of the same hydrogenation catalyst as in the hydrodewaxing. 2 After the hydrodewaxing and hydrofinishing, a second reclaimed base oil was obtained.

[0061] The obtained second recycled base oil was blended with another lubricant base oil (YU-6) having a kinematic viscosity at 100 ° C of 6.3 cSt, a viscosity index of 130, a pour point of -12 ° C, and a CCP viscosity at -30 ° C of 6200 cP to obtain a lubricant base oil mixture. The amount of the second recycled base oil blended here was 20 vol% of the lubricant base oil mixture.

[0062] The properties and various characteristics of the lubricant base oil mixture produced by the above-mentioned production method were measured. As a result of the measurements, the lubricant base oil mixture had a specific gravity of 0.84, a kinematic viscosity at 100°C of 7.3 cSt, a viscosity index (VI) of 129, and a kinematic viscosity at -33°C. The sulfur, nitrogen, and chlorine contents were each less than 1 ppm, and the mixture contained almost no impurities except for unavoidable trace amounts. In addition to the above, the properties measured for the lubricant base oil mixture are shown in Table 3 below.

[0063] [Table 3]

[0064] The lubricant base oil blend was found to have a viscosity index of at least 120 and a saturation level of at least 95%, and thus met the criteria for Group III lubricant base oil in Table 1. The lubricant base oil blend had a bright and clean color when evaluated by the naked eye and exhibited a Saybolt Color of at least 27 as measured according to ASTM D156. That is, the lubricant base oil is a lubricant base oil having a water white rating and has high thermal stability at high temperatures.

[0065] In addition, the lubricating base oil mixture exhibits a low absorbance of up to 3.0 (up to 1.0 for a wavelength of 325 nm) measured in accordance with ASTM D2008 for UV having a wavelength of 260 to 350 nm, and particularly for UV having a wavelength of 325 nm, and therefore it can be confirmed that the mixture has high stability against UV.

[0066] In this way, when a certain amount of recycled base oil derived from waste lubricating oil is used as a feedstock for the production of lubricating base oil, the stability and yield of the final product, the lubricating base oil, can be increased, and there is an environmental advantage in that the waste lubricating oil is recycled as a feedstock for the production of lubricating base oil rather than simply being discarded.

[0067] The present disclosure has been described in detail above using specific embodiments, but the embodiments are intended to specifically explain the present disclosure, and the present disclosure is not limited thereto. It should be understood that modifications and improvements can be made by a person having ordinary knowledge in the relevant field within the technical spirit of the present disclosure.

[0068] Any simple variations or modifications of the present disclosure belong to the scope of the present disclosure, and the specific scope of protection of the present disclosure will be defined by the appended claims.

Claims

1. 1. A method for producing a lubricant base oil blend, comprising the steps of: Providing a refined fraction derived from a used lubricant, the refined fraction derived from the used lubricant being derived from a lubricant comprising a lubricant base oil below API Group III, the refined fraction derived from the used lubricant comprising a vacuum ion refined oil, a first reclaimed base oil, or a combination thereof; A dewaxing step of dewaxing the refined fraction derived from the waste lubricating oil to produce a second recycled base oil; and blending the second recycled base oil with another lubricant base oil to produce a Group III or higher lubricant base oil blend.

2. 2. The method for producing the lubricating base oil blend of claim 1, wherein the refined fraction derived from the used lubricating oil has a sulfur content of from 200 ppm to 3000 ppm, a nitrogen content of from 100 ppm to 1200 ppm, and a kinematic viscosity at 100 ° C. of from 4 to 11 cSt.

3. 2. The method of claim 1, wherein the dewaxing step comprises hydrotreating, hydrodewaxing, and hydrofinishing the refinery fraction derived from the used lubricating oil.

4. The hydrodewaxing step is carried out in the presence of a catalyst comprising at least one of an EU-2 zeolite support, an alumina support and a silica-alumina support, at a temperature of 300° C. to 350° C. and at a pressure of 60 kg / cm ２ More than 150kg / cm ２ 4. A method for producing the lubricant base oil blend of claim 3, carried out at a pressure of:

5. 5. The method of producing a lubricant base oil blend according to claim 4, wherein the catalyst comprises Co, Ni, Pt, Pd, Mo, W, or a combination thereof as a metal active component.

6. The method of claim 1, wherein the separate lubricant base oil has a kinematic viscosity at 100°C of 6 to 7 cSt, a viscosity index of 120 or greater, a pour point of -10°C or less, and a CCS (Cold Crank Simulator) viscosity at -30°C of 5400 cP or less.

7. The method for producing a lubricant base oil blend according to claim 1, wherein the amount of the second recycled base oil blended in the blending step is 1 to 30 volume % of the Group III or higher lubricant base oil blend.

8. A lubricant base oil mixture comprising the second recycled base oil according to any one of claims 1 to 7.

9. The lubricant base oil mixture containing the second recycled base oil according to claim 8, wherein the lubricant base oil mixture has a viscosity index of 120 or more and a saturation degree of 90% or more.

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