COPROCESSING OF USED LUBRICATING OIL TO INCREASE GROUP II/III BASE STOCK PRODUCTION

CROSS REFERENCE TO RELATED APPLICATIONS

[0001]This application claims the priority of U.S. Provisional Patent Application No. 63/684,215, Filed Aug. 16, 2024, which is incorporated by reference in its entirety.

FIELD

[0002]This disclosure relates to base stocks, and more particularly, example embodiments relate to base stocks made from used lubricating oils, blends of base stocks, formulated lubricant compositions containing the base stocks, and uses of base stocks.

BACKGROUND

[0003]Base stocks are the major constituent in finished lubricants and contribute significantly to their properties. For example, engine oils are finished crankcase lubricants intended for use in automobile engines and diesel engines and contain two general components, namely, a base stock (one base stock or a blend of base stocks) and additives. In general, a few lubricating base stocks are used to manufacture a variety of engine oils by varying the mixtures of individual lubricating base stocks and individual additives. Base stocks are also used for other purposes and industries such as processing oils for manufacturing and industrial oils in the marine and paper industries.

[0004]According to the American Petroleum Institute (API) classifications, base stocks are categorized in five groups based on their saturated hydrocarbon content, sulfur level, and viscosity index (Table 1). Lubricant base stocks are typically produced on a large scale from petroleum sources. Group I, II, and III base stocks are all derived from crude oil via extensive processing, such as solvent extraction, solvent or catalytic dewaxing, and hydroisomerization. Group III base stocks can also be produced from synthetic hydrocarbon liquids obtained from natural gas, coal or other fossil resources, Group IV base stocks are polyalphaolefins (PAOs), and are produced by oligomerization of alpha olefins, such as 1-decene. Group V base stocks include all base stocks that do not belong to Groups I-IV, such as naphthenics, polyalkylene glycols (PAG), and esters.

[0005]Base stocks are the key building blocks of lubricants and greases. A base stock is typically defined as a single lubricant component produced by a single manufacturer. The terms base stocks and base oils are often used interchangeably, but there are differences. A base stock is a single product, usually defined by its viscosity grade. A mixture of one or more base stocks in a finished lubricant is a base oil. A base oil is always defined in the context in the formulated lubricant. Base oil properties can vary depending on their API group. Base stocks are generally produced from the higher boiling fractions recovered from a vacuum distillation operation. They may be prepared from either petroleum-derived or from syncrude-derived feed stocks or from synthesis of lower molecular weight molecules. Base stocks are blended to form a base oil to which additives are added to form the finished lubricant. Additives are chemicals which are added to base stock to improve certain properties in the finished lubricant so that it meets the minimum performance standards for the grade of the finished lubricant. For example, additives added to engine oils may be used to improve oxidation stability of the lubricant, increase its viscosity, raise the viscosity index, and control deposits.

[0006]Lubricating oils are utilized in machinery for various purposes such as to lubricate surfaces, cool components, provide anti-corrosion and other modifiers to surfaces, and catch contaminants from combustion. Lubricating oils are utilized in a variety of applications including, but not limited to, vehicle engines, industrial gearboxes and pumps, compressors, and hydraulic units. When the lubricating oil is circulated throughout the machinery, the lubricating oil becomes contaminated with metal shavings and debris from the machinery as well as chemical impurities such as water, fuel, and combustion products.

[0007]Lubricating oils are changed when the oil no longer meets the specification requirements or at regular intervals. The lubricating oil becomes “used up” when the additive package in the lubricating oil is depleted and the oil becomes contaminated. However, the base oils which make up the bulk volume of the lubricating oils are not used up under normal engine conditions and thus can be recycled to form new base oils. Re-refiners may utilize the used lubricating oil in a reclamation process to recover the base stock fractions in the used lubricating oil. The reclamation process typically includes multiple cleaning and stripping steps to remove physical and chemical contaminants from the used lubricating oil followed by liquid-liquid extraction processes to recover a Group I base stock and low pressure hydrotreating to recover group II base stocks.

SUMMARY

[0008]The invention includes methods for producing base stocks from used oils such as pre-processed used lubricating oils. According to an embodiment, the invention includes a method for producing base stock from pre-processed used lubricating oil comprising: introducing a feed stream comprising pre-processed used lubricating oil and vacuum gas oil into a solvent extraction unit; contacting the feed stream with a solvent in the solvent extraction unit and forming a raffinate stream comprising lubricant boiling range hydrocarbons; introducing the raffinate stream into a hydrotreatment section; contacting the raffinate stream with a hydrotreatment catalyst and hydrogen in the hydrotreatment section and forming a hydro-converted product; stripping the hydro-converted product of ammonia and hydrogen sulfide, introducing the hydro-converted product into a catalytic dewaxing section; contacting the hydro-converted product with a dewaxing catalyst and hydrogen in the catalytic dewaxing section at catalytic dewaxing conditions effective to dewax at least a portion of the hydro-converted product to form a dewaxed effluent; introducing the dewaxed effluent into a hydrofinishing section; contacting the dewaxed effluent with a hydrofinishing catalyst and hydrogen in the hydrofinishing section at hydrofinishing conditions to hydrofinish at least a portion of the dewaxed effluent to form a hydrofinished effluent; and introducing the hydrofinished effluent into a separation unit and separating at least a portion of the lubricant boiling range hydrocarbons to form a base stock fraction.

[0009]According to a further embodiment, the invention includes a method for producing base stock from pre-processed used oils comprising: introducing a feed stream comprising pre-processed used lubricating oil and vacuum gas oil into a solvent extraction unit, wherein the feed stream comprises about 5 vol. % to about 15 vol. % pre-processed used lubricating oil, and contacting the feed stream with a solvent to form a raffinate stream comprising lubricant boiling range hydrocarbons; contacting the raffinate stream with a hydrotreatment catalyst and hydrogen at hydrotreatment conditions effective to hydrotreat at least a portion of the sulfur to H₂S and forming a hydro-converted product; contacting the hydro-converted product with a dewaxing catalyst and hydrogen at catalytic dewaxing conditions effective to dewax at least a portion of the hydro-converted product to form a dewaxed effluent; contacting the dewaxed effluent with a hydrofinishing catalyst and hydrogen at hydrofinishing conditions to hydrofinish at least a portion of the dewaxed effluent to form a hydrofinished effluent; and separating lubricant boiling range hydrocarbons from the hydrofinished effluent to form a base stock fraction wherein the lubricant boiling range hydrocarbons have a boiling point in a range of about 343° C. to about 566° C.

[0010]These and other features and attributes of the disclosed methods for producing base stocks from pre-processed used lubricating oils, base stocks made from used lubricating oils, blends of base stocks, formulated lubricant compositions containing the base stocks, and uses of base stocks of the present disclosure and their advantageous applications and/or uses will be apparent from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]To assist those of ordinary skill in the relevant art in making and using the subject matter hereof, reference is made to the appended drawings, wherein:

[0012]FIG. 1s a schematic illustration of a process for processing used lubricating oil in accordance with certain embodiments of the present disclosure.

DETAILED DESCRIPTION

[0013]Disclosed herein are methods to increase the production of group II, and group III base stocks, and more particularly, example embodiments relate to methods to form high quality Group II base stock, and Group III base stock from co-processing vacuum gas oil (VGO) with pre-processed used lubricating oil. The example embodiments disclosed herein have several advantages over previously disclosed methods of processing a used lubricating oil, only some of which may be alluded to herein. The Group II base stock, and Group III produced according to the example embodiments disclosed herein have viscosity index (VI), cold crank simulator (CCS), and other relevant physical properties within range of conventionally produced Group II base stock, and Group III base stock, thereby allowing the Group II base stock, and Group III base stock produced from the used lubricating oil to be integrated into existing blending schemes.

Feedstocks

[0014]In various embodiments, the used lubricating oil employed in the present process may be collected from various sources including industrial, commercial, and/or residential sources and may include mixtures of used lubricating oils from these sources. In embodiments, the used lubricating oil has been used in an engine, transmission, or other lubricating application. The used lubricating oil may include, without limitation, oils such as transmission oil, gear oil, engine oil, crankcase oil, compressor oil, pump oil, hydraulic oil, or any combination thereof. The used lubricating oil in some examples includes a mixture of petroleum mineral oils derived from the processing of petroleum crude and/or oils, used lubricating oil containing base stocks derived from fischer tropsch waxes, used lubricating oil containing base stocks derived from polyolefin processing, used mineral oils, and used synthetic base oils. It should be noted that a polyalphaolefin or unsaturated PAO of the present disclosure can be introduced into a stream during the re-refining process, for example before or after distillation/hydrogenation. As used herein, “polyalpha-olefin(s)” (“PAO(s)”) includes any oligomer(s) and polymer(s) of one or more alpha-olefin monomer(s). PAOs are oligomeric or polymeric molecules produced from the polymerization reactions of alpha-olefin monomer molecules in the presence of a catalyst system, optionally further hydrogenated to remove residual carbon-carbon double bonds therein. Thus, the PAO can be a dimer, a trimer, a tetramer, or any other oligomer or polymer comprising two or more structure units derived from one or more alpha-olefin monomer(s). In embodiments, the used lubricating oil includes additive packages including but not limited to antiwear additives, detergents, dispersants, viscosity modifiers, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure agents, wax modifiers, other viscosity modifiers, fluid-loss additives, seal compatibility agents, lubricity agents, anti-staining agents, chromophoric agents, anti-foam agents, antioxidants, anti-rust additives, anti-wear additives, pour point depressant, demulsifiers, emulsifiers, densifiers, wetting agents, gelling agents, tackiness agents, colorants, and others. In embodiments the used lubricating oil includes water and insoluble particulates such as carbon, metal shavings, and combustion deposits.

[0015]In embodiments, the used lubricating oil is subjected to a series of pre-processing steps whereby the used lubricating oil is cleaned of at least a portion of the contaminants such as additives, water, and insoluble particles. For example, water may be removed in a dehydration unit whereby water may be stripped, decanted, or otherwise removed from the bulk used lubricating oil. In embodiments, a filtration unit is utilized to filter solid particulates from the used lubricating oil. In embodiments, the used lubricating oil may be subjected to vacuum distillation, chemical addition, or other separation steps.

[0016]In embodiments, pre-processed used lubricating oil is utilized as a feedstock in the disclosed methods of producing base stocks. The feedstock for the process can have any viscosity. In various embodiments, the pre-processed used lubricating oil has a kinematic viscosity at 100° C. (KV100) of at least 3 centistokes (cSt). In various embodiments, the feedstock has a KV100 at a point in a range of 3 cSt to 8 cSt. Alternatively, the feedstock has a KV100 at a point in a range of 3 cSt to 5.5 cSt, at a point in a range of 5.5 cSt to 8 cSt, at a point in a range of 4 cSt to 6 cSt or any ranges therebetween. Although the feedstock can have any viscosity index (VI), in various embodiments the used lubricating oil has a VI of at least90, preferably in a range of 100-120. In some embodiments, the feedstock has a VI at a point in a range of from 90 to130. Alternatively, the feedstock has a VI at a point in a range of from 90 to115, at a point in a range of from 115 to 130, or any ranges therebetween. In embodiments, the pre-processed used lubricating oil has an initial boiling point (T5) at a point in a range of 330° C. to 380° C. and a final boiling point (T95) in a range of 450° C. to 560° C. In further embodiments the pre-processed used lubricating oil contains low levels of contaminants, including spent additives and wear materials, such as about 0.00 wt. %, 0.01 to 5.0 wt. %, 0.05 to 2.0 wt. % contaminant loading, or any ranges there-between.

[0017]In some embodiments, the pre-processed used lubricating oil contains greater than 500 wppm sulfur as determined by ASTM 2622. When the pre-processed used lubricating oil contains greater than 500 wppm sulfur, the oil is considered a “sour” feed. In embodiments, the pre-processed used lubricating oil contains sulfur in an amount of 500 wppm to 5,000 wppm sulfur. In example embodiments including a hydrotreatment process and/or a sour hydrocracking process, the feed can have a sulfur content of 500 wppm to 1000 wppm, or 1000 wppm to 2500 wppm, 2500 wppm to 5000 wppm, or any ranges therebetween. Additionally or alternately, the nitrogen content may be in a range of 0 wppm to 1000 wppm, 50 wppm to 500, 500 to 1000 wppm, or any ranges therebeween. In some embodiments, the feed can correspond to a “sweet” feed, so that the sulfur content of the feed is about 10 wppm to about 200 wppm and/or the nitrogen content is about 1 wppm to about 20 wppm.

[0018]In embodiments, the pre-processed used lubricating oil contains halides in an amount of 0 wppm to 100 wppm, such as from 0 wppm to 25 wppm, 25 wppm to 50 wppm, 50 wppm to 100 wppm, or any ranges therebetween. In further embodiments, the pre-processed used lubricating oil contains a total content of metal contaminants by D5185 such as phosphorus, calcium, zinc and silicon is typically between from 0 wppm to 200 wppm, such as from 0 wppm to 25 wppm, 25 wppm to 100 wppm, 100 wppm to 200 wppm, or any ranges therebetween.

[0019]In embodiments, the pre-processed used lubricating oil is co-processed with vacuum gas oil (VGO). As used herein, “vacuum gasoil,” “VGO,” “vacuum gasoil-range,” and grammatical variations thereof, refer to a hydrocarbon composition characterized by a T₅ distillation temperature in a range of about 644° F. (340° C.) to about 716° F. (380° C.) and a T₉₅ distillation temperature in a range of about 840° F. (460° C.) to about 1058° F. (580° C.) as measured according to ASTM D2887. Vacuum gas oil is typically produced from vacuum distillation of atmospheric column bottoms from an atmospheric distillation unit.

Process for Producing Base Stocks

[0020]FIG. 1s a block flow diagram of a process 100 to produce base stocks in accordance with some embodiments of the present disclosure. Process 100 begins with production of vacuum gas oil in vacuum crude distillation unit 102. An atmospheric column bottoms is introduced into the vacuum crude distillation unit 102 and separated into various fractions based on boiling point. Vacuum crude distillation unit 102 operates at reduced pressures to enable the separation of heavier components without excessive thermal cracking. The atmospheric column bottoms is preheated and enters the vacuum distillation column, where it is separated into lighter fractions such as gas oil including light vacuum gas oil and heavy vacuum gas oil. Vacuum gas oil 104 is withdrawn from vacuum crude distillation unit 102 and optionally introduced into vacuum gas oil tank farm 106 for storage before use. Vacuum gas oil 104 corresponds to fractions of conventional vacuum gas oil (light, medium, and/or heavy vacuum gas oil) such as those gas oils with a viscosity index of 40-80. In embodiments, the vacuum gas oil corresponds to a light vacuum gas oil having a boiling range of about T5 350-T95 500° C. In further embodiments, the vacuum gas oil has a KV100 at a point in a range of 5 cSt to 7 cSt, a sulfur content a point in a range of 8000 ppm to14000 ppm, a nitrogen content of 600 ppm to 800 ppm, and is free of or having below detection limits of halides.

[0021]Pre-processed used lubricating oil contains lubricant boiling point range hydrocarbons as well as remaining additive packages and contaminants. As the pre-processed used lubricating oil contains molecular components and boiling range thereof for lubricant applications, the process severity to reclaim and re-refine the lubricant molecules can be reduced as compared to conventional processing for lube production. Co-processing of vacuum gas oil and pre-processed used lubricating oil increases the yield of the lubricant boiling point range hydrocarbons in the raffinate stream exiting the solvent extraction unit 114 which through further processing, will subsequently provide a higher yield of lubricant boiling point range hydrocarbons after fractionation.

[0022]Pre-processed used lubricating oil is stored in used oil tank farm 108. Pre-processed used lubricating oil 110 is withdrawn from used oil tank farm 108 and combined with vacuum gas oil from vacuum gas oil tank farm 106 to form feed stream 112 which is then introduced into solvent extraction unit 114. In embodiments, a feed to solvent extraction unit 114 includes the pre-processed used lubricating oil in an amount at a point in a range of 1 vol. % to 50 vol. %. Alternatively, in an amount at a point in a range of 1 vol. % to 5 vol. %, in an amount at a point in a range of 5 vol. % to 15 vol. %, in an amount at a point in a range of 15 vol. % to 25 vol. %, in an amount at a point in a range of 25 vol. % to 35 vol. %, in an amount at a point in a range of 35 vol. % to 50 vol. %, or in an amount at a point in a range of any ranges therebetween.

[0023]In embodiments, the pre-processed used lubricating oil can optionally be demetallized prior to introduction into solvent extraction unit 114. Metals in the pre-processed used lubricating oil are mainly present in the form of remaining additive package not removed during pre-processing.

[0024]In solvent extraction unit 114, the co-feed including vacuum gas oil and pre-processed used lubricating oil is contacted and mixed with a solvent to selectively remove multi-ring aromatic and polar components in an extract phase while leaving the more paraffinic components in a raffinate phase. Naphthenes are distributed in the extract and raffinate phases. In embodiments, the solvent includes phenol, furfural and N-methyl pyrrolidone, or combinations thereof. By controlling the solvent to oil ratio, extraction temperature and method of contacting feed to be extracted with solvent, the degree of separation between the extract and raffinate phases is controlled. The raffinate contains the lubricant boiling point range hydrocarbons from feed 112.

[0025]In embodiments, the raffinate from the solvent extraction is extracted to any suitable degree such that the lowest quality molecules are removed from the feed. Raffinate yield may be maximized by controlling extraction conditions, for example, by lowering the solvent to oil treat ratio and/or decreasing the extraction temperature. The raffinate from the solvent extraction unit is stripped of solvent and withdrawn from solvent extraction unit 114 as raffinate stream 118 and introduced into hydrotreatment section 122. Extract stream 120 containing the extracted components from feed stream 112 is withdrawn from solvent extraction unit 114 which can be further hydrodesulfurized followed by cracking in a fluidized catalytic cracker to fuel range hydrocarbons, for example. In embodiments, the raffinate stream 118 has a viscosity index of from about 90 to about 110. In embodiments, raffinate stream 118 contains contaminants, such as sulfur and nitrogen. The sulfur content of the raffinate can be from 100 ppm by weight to up to 10,000 ppm or more of sulfur. In various embodiments, the raffinate stream 118 is combined with a hydrogen containing gas prior to introduction into hydrotreatment section 122.

[0026]Hydrotreatment section 122 includes a hydrotreatment catalyst. In hydrotreatment section 122 the raffinate stream 118 is mixed with hydrogen and contacted with a hydrotreating catalyst at conditions suitable to remove heteroatoms such as sulfur and nitrogen from the raffinate and increase the H:C ratio of the raffinate. In embodiments where the raffinate feed contains greater than 500 wppm sulfur, the hydrotreatment conditions correspond to sour hydrotreatment conditions. The hydrogen facilitates the reaction by converting heteroatoms into H₂S and/or NH₃ which are then removed from the bulk raffinate. Main quality improvement is VI and saturates aromatic ratio.

[0027]In embodiments, the hydrotreatment section 122 is operated at hydrotreatment conditions. In embodiments, the hydrotreatment section is operated at a temperature at a point in a range of 300° C. to 450° C. Alternatively, the hydrotreatment section it is operated at a temperature at a point in a range of 300° C. to 350° C., a temperature at a point in a range of 350° C. to 400° C., a temperature at a point in a range of 400° C. to 450° C., or any ranges therebetween.

[0028]In embodiments, the hydrotreatment section is operated at hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 3000 psig (20.68 MPa). Alternatively, the hydrotreatment section is operated at a hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 1000 psig (6.89 MPa), a hydrogen partial pressure at a point in a range of 1000 psig (6.89 MPa) to 2000 psig (13.78 MPa), a hydrogen partial pressure at a point in a range of 2000 psig (13.78 MPa) to 3000 psig (20.68 MPa), or any ranges therebetween.

[0029]In embodiments, the hydrotreatment section is operated at a Liquid Hourly Space Velocity (LHSV) at a point in a range of 0.1-5.0 h⁻¹. Alternatively, at a LHSV at point in a range of 0.1-1.0 h⁻¹, at a LHSV at a point in a range of 2.0-3.0 h⁻¹, at a LHSV at a point in a range of 3.0-5.0 h⁻¹, or any ranges therebetween in the hydrotreatment section.

[0030]In embodiments, the hydrotreatment section is operated at a total treat gas ratio, i.e. the treat gas at reactor inlet and all inter-bed gas quenches, at a point in a range of 1000 scf/B to 6000 scf/B. Alternatively, the hydrotreatment section is operated at a total treat gas ratio at a point in a range of 1000 scf/B to 2000 scf/B, at a point in a range of 2000 scf/B to 4000 scf/B, at a point in a range of 4000 scf/B to 6000 scf/B, or any ranges therebetween.

[0031]In embodiments, hydrotreating section includes a hydrotreating catalyst such as those catalysts containing Group VIB metals, such as molybdenum and/or tungsten, and non-noble Group VIII metals, such as, iron, cobalt and nickel and mixtures thereof. These metals or mixtures of metals are typically present as oxides or sulfides on refractory metal oxide supports. Alternatively, the hydrotreating catalyst includes a bulk metal catalyst, or a combination of stacked beds of supported and bulk metal catalyst.

[0032]Hydrotreatment is carried out in the presence of hydrogen. A hydrogen stream is, therefore, fed or injected into a vessel or reaction zone or hydrotreating section in which the hydrotreating catalyst is located. Hydrogen, which is contained in a hydrogen “treat gas,” is provided to the reaction zone. Treat gas can be either pure hydrogen or a hydrogen-containing gas, which is a gas stream containing hydrogen in an amount that is sufficient for the intended reaction(s), optionally including one or more other gasses (e.g., and light hydrocarbons such as methane), and which will not adversely interfere with or affect either the reactions or the products. The effluent from the demetallization section is contacted with the hydrogen in the presence of the hydrotreating catalyst to reduce amount the sulfur, nitrogen, and/or aromatic in the feed.

[0033]The hydro-converted product 124 is withdrawn from hydrotreatment section 122 and introduced into stripper 144 where the hydro-converted product is stripped to remove H2S, ammonia, and recycle hydrogen back to dewaxing section. Stripped effluent 146 is withdrawn from stripper 144 and introduced into dewaxing section 126.

[0034]In dewaxing section 126 the lubricant boiling range hydrocarbons and naphtha/distillate fuel boiling range hydrocarbons, if present, from hydro-converted product 124 are reacted with hydrogen in the presence of a suitable dewaxing catalyst at conditions effective to lower the pour point of the lubricant boiling range hydrocarbons. Catalytic dewaxing can also convert a portion of the lubricant boiling range to lower boiling materials which are separated from the heavier base stock fraction in separation unit 134. This base stock fraction can then be further fractionated into two or more base stocks in separation unit 134. Separation of the lower boiling material may be accomplished either prior to or during fractionation of the heavy base stock fraction material into the desired base stocks.

[0035]In embodiments, dewaxing section 126 includes a dewaxing catalyst that performs dewaxing primarily by isomerizing a hydrocarbon feedstock. In some embodiments, an aromatics saturation catalyst is included in the dewaxing section prior to the dewaxing catalyst and/or after the dewaxing catalyst. In embodiments, the catalysts are zeolites with a unidimensional pore structure. In some embodiments, the catalyst includes 10-member ring pore zeolites, such as EU-1, ZSM-35 (or ferrierite), ZSM-11, ZSM-57, NU-87, SAPO-11, and ZSM-22. In embodiments, the dewaxing catalyst includes Theta-1, NU-10, EU-13, KZ-1, and NU-23, EU-2, EU-11, ZBM-30, ZSM-48, or ZSM-23. In embodiments, the dewaxing catalyst includes a metal hydrogenation component. The metal hydrogenation component is typically a Group VI and/or a Group VIII metal. In embodiments, the metal hydrogenation component is Pt, Pd, or a mixture thereof. In an alternative embodiment, the metal hydrogenation component can be a combination of a non-noble Group VIII metal with a Group VI metal. Suitable combinations can include Ni, Co, or Fe with Mo or W and/or Ni with Mo or W.

[0036]In embodiments, dewaxing section 126 is operated at catalytic dewaxing conditions including a temperature at a point in a range of from 300° C.-400° C. Alternatively, a temperature at a point in a range of from 200° C. to 250° C., a temperature a point in a range of from 250° C. to 350° C., a temperature a point in a range of from 350° C. to 450° C., or a temperature any ranges therebetween.

[0037]In embodiments, the dewaxing section 126 is operated at hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 3000 psig (20.68 MPa). Alternatively, the dewaxing section 126 is operated at a hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 1000 psig (6.89 MPa), a hydrogen partial pressure at a point in a range of 1000 psig (6.89 MPa) to 2000 psig (13.78 MPa), a hydrogen partial pressure at a point in a range of 2000 psig (13.78 MPa) to 3000 psig (20.68 MPa), or any ranges therebetween.

[0038]In embodiments, the dewaxing section 126 is operated at a LHSV at a point in a range of 0.5 to 5.0 v/v/hr. Alternatively, a LHSV at a point in a range of 0.5 to 1 v/v/hr, a LHSV at a point in a range of 1.0 to 3.0 v/v/hr, a LHSV at a point in a range of 3.0 to 5.0 v/v/hr., or any ranges therebetween.

[0039]In embodiments, the dewaxing section 126 is operated at a total treat gas ratio, i.e. the treat gas at reactor inlet and all inter-bed gas quenches, at a point in a range of 1000 scf/B to 5000 scf/B. Alternatively, the dewaxing section 126 is operated at a total treat gas ratio at a point in a range of 1000 scf/B to 2000 scf/B, at a point in a range of 2000 scf/B to 4000 scf/B, at a point in a range of 4000 scf/B to 5000 scf/B, or any ranges therebetween.

[0040]Dewaxed effluent stream 128 includes lubricant boiling range hydrocarbons and naphtha/distillate fuel boiling range hydrocarbons generated from dewaxing, if present. Dewaxed effluent stream 128 is withdrawn from dewaxing section 126 and introduced into hydrofinishing section 130.

[0041]In embodiments, hydrofinishing section 130 includes a hydrofinishing catalyst that includes Pt, Pd, or a combination thereof on a support such as alumina or titania. In embodiments the hydrofinishing catalyst includes hydrotreating catalysts with Pt or Pd supported on alumina, amorphous alumina/silica, and/or zeolite. In embodiments, the hydrofinishing catalyst can include from 0.1 wt. % to 2.0 wt. % of hydrogenation metal relative to the weight of the support. Due to the low acidity support, this type of catalyst causes little or no cracking of feed while being effective for reduction of single ring and multi-ring aromatics.

[0042]In some Embodiments, an aromatic saturation process can optionally include multiple beds and/or sections of hydrofinishing catalyst. The multiple beds or sections can be organized in a single reactor or in a plurality of reactors.

[0043]In embodiments, hydrofinishing section 130 is operated at hydrofinishing conditions. In embodiments, the hydrofinishing section is operated at a temperature at a point in a range of 200° C. to 280° C. Alternatively, the hydrofinishing section 130 is operated at a temperature at a point in a range of 200° C. to 230° C., a temperature at a point in a range of 230° C. to 250° C., a temperature at a point in a range of 250° C. to 280° C., or any ranges therebetween.

[0044]In embodiments, hydrofinishing section 130 is operated at is operated at hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 3000 psig (20.68 MPa). Alternatively, the hydrofinishing section 130 is operated at a hydrogen partial pressure at a point in a range of 500 psig (3.44 MPa) to 1000 psig (6.89 MPa), a hydrogen partial pressure at a point in a range of 1000 psig (6.89 MPa) to 2000 psig (13.78 MPa), a hydrogen partial pressure at a point in a range of 2000 psig (13.78 MPa) to 3000 psig (20.68 MPa), or any ranges therebetween.

[0045]In embodiments, hydrofinishing section 130 is operated at a total treat gas ratio, i.e. the treat gas at reactor inlet and all inter-bed gas quenches, at a point in a range of 1000 scf/B to 5000 scf/B. Alternatively, the hydrotreatment section is operated at a total treat gas ratio at a point in a range of 1000 scf/B to 2000 scf/B, at a point in a range of 2000 scf/B to 4000 scf/B, at a point in a range of 4000 scf/B to 5000 scf/B, or any ranges therebetween.

[0046]In embodiments, hydrofinishing section 130 is operated at an LHSV at a point in a range of 0.5-5.0 h⁻¹ in the hydrofinishing section. Alternatively, the hydrofinishing unit is operated at an LHSV at a point in a range of 0.5-1.0 h⁻¹, at a LHSV point in a range of 1.0-3.0 h⁻¹, at a LHSV point in a range of 3.0-5.0 h⁻¹, or any LHSV ranges therebetween in the hydrofinishing section.

[0047]After hydrofinishing, the aromatics content of the hydrofinished lubricant boiling range product can be in a range of 0.0 wt. % to 3.0% wt. %. In embodiments, the aromatics content is 1.5 wt. % or less, or 1.0 wt. % or less, or 0.5 wt. % or less, or 0.4 wt. % or less, or 0.3 wt. % or less, or 0.2 wt. % or less, or 0.1 wt. % or less. Additionally, or alternately, the 3-ring aromatics content of the hydrofinished lubricant boiling range product can be at a point in a range of 0.000 wt. % to 0.100 wt. %. In embodiments, the 3-ring aromatics content is 0.050 wt. % or less, or 0.040 wt. % or less, or 0.035 wt. % or less, or 0.030 wt. % or less, or 0.025 wt. % or less, or 0.020 wt. % or less, or 0.015 wt. % or less, or 0.010 wt. % or less.

[0048]Hydrofinished effluent stream 132 is withdrawn from hydrofinishing section 130 and introduced into separation unit 134. Hydrofinished effluent stream 132 includes lubricant boiling range hydrocarbons and naphtha/distillate fuel boiling range hydrocarbons generated from dewaxing. Separation unit 134 is configured to separate the hydrofinished lubricant boiling range product from light ends such as naphtha/distillate fuel boiling range. The fuel boiling point range hydrocarbons and light ends are withdrawn as fuel stream 136 and sent to fuel blending pool 138. In embodiments, separation unit 134 includes equipment such as strippers, distillation columns, fractionators, or any other equipment suitable for separating hydrofinished lubricant boiling range product from the fuel range light ends. In embodiments, hydrofinished effluent stream 132 contains lubricant boiling range hydrocarbons corresponding to a Group II base stock and/or a Group III base stock. Group II base stocks contain at least 90 wt. % saturated molecules, less than 0.03 wt. % sulfur, and a viscosity index of at least 80 but less than 120. A Group III base stock can generally correspond to a base stock that satisfies the requirements for a Group II base stock while also having a VI in excess of 120. Base stock fraction 140 is withdrawn from separation unit 134 and introduced into storage 142.

Properties of Base Stock

[0049]The viscosity-temperature relationship of a lubricating oil is one of the criteria which may be considered when selecting a lubricant for a particular application. Viscosity Index (VI) is an empirical, unitless number which indicates the rate of change in the viscosity of an oil within a given temperature range. Fluids exhibiting a relatively large change in viscosity with temperature are said to have a low viscosity index. A low VI oil, for example, will thin out at elevated temperatures faster than a high VI oil. Usually, the high VI oil is more desirable because it has higher viscosity at higher temperature, which translates into better or thicker lubrication film and better protection of the contacting machine elements. In embodiments, the base stocks of the present disclosure have a viscosity index (VI) of at least 80, such as a VI at a point in a range of 80-120. Alternatively, the base stocks of the present disclosure have a viscosity index at a point in a range of 80-90, at a point in a range of 90-100, at a point in a range of 100-110, at a point in a range of 110-120, at a point in a range of 120-130 or any ranges therebetween. Viscosity index is determined according to ASTM method ASTM D2270-10 (2016). In further embodiments, the base stock of the present disclosure is a Group II base stock and has a VI at a point in a range of 115-120. In further embodiments, the base stock of the present disclosure is a Group III base stock and has a VI at a point in a range of 120-124.

[0050]As used herein, “kinematic viscosity at 100° C.” will be used interchangeably with “KV100” and “kinematic viscosity at 40° C.” will be used interchangeably with “KV40”. KV100 is determined according to ASTM D445-24 and KV40 is determined according to ASTM D445-24. In embodiments, the base stock has a kinematic viscosity at 100° C. (KV100) at a point in a range of 3 cSt (centistokes) to about 8 cSt. Alternatively, the base stock has a kinematic viscosity at 100° C. at a point in a range of 3 cSt to 4 cSt, at a point in a range of 4 cSt to 5 cSt, at a point in a range of 4 cSt to 6 cSt, at a point in a range of 5 cSt to 6 cSt, at a point in a range of 6 cSt to 7 cSt, at a point in a range of 7 cSt to 8 cSt, or any ranges therebetween. In embodiments, the base stock has a kinematic viscosity at 40° C. (KV40) at a point in a range of 20 cSt to about 40 cSt. Alternatively, the base stock has a kinematic viscosity at 40° C. at a point in a range of 20 cSt to 25 cSt, at a point in a range of 25 cSt to 30 cSt, at a point in a range of 30 cSt to 35 cSt, at a point in a range of 35 cSt to 40 cSt, or any ranges therebetween.

[0051]In embodiments, the base stock of the present disclosure has a pour point at a point in a range of −12° C. to −25° C. Alternatively, the base stock of the present disclosure has pour point at a point in a range of from 0° C. to −10° C., at a point in a range of from −10° C. to −20° C., at a point in a range of from −20° C. to −25° C., or any ranges therebetween. The pour point is measured according to ASTM D7346-15 (2021).

[0052]In embodiments, the base stock of the present disclosure has a density at a point in a range of 0.820 g/cm³ to 0.850 g/cm³. Alternatively, the base stock of the present disclosure has a density at a point in a range of 0.820 g/cm³ to 0.835 g/cm³, at a point in a range of 0.835 g/cm³ to 0.840 g/cm³, at a point in a range of 0.840 g/cm³ to 0.845 g/cm³, at a point in a range of 0.845 g/cm³ to 0.850 g/cm³, or any ranges therebetween. The density is measured according to ASTM D4052-22.

[0053]The high temperature stability of a lubricating oil is often an important consideration when selecting a base stock for a particular application. The Noack volatility of a base stock measures the evaporative loss of engine oils exposed to elevated temperatures. The Noack volatility is measured by ASTM D5800-21, Method B test. In embodiments, the base stocks of the present disclosure have a Noack volatility of less than 15. wt. %. In embodiments, the base stock has a Noack volatility at a point in a range of 10 wt. % to 12. wt. %. Alternatively, the base stock has a Noack volatility a point in a range of 0 wt. % to 4. wt. %, a point in a range of 4 wt. % to 8. wt. %, a point in a range of 8 wt. % to 12. wt. %, or any ranges therebetween.

[0054]The low temperature viscosity of a lubricating oil is often an important consideration when selecting a base stock for a particular application. The cold cranking simulator (CCS) as outlined in ASTM D5293-20 can be used to estimate the low temperature performance of the base stock at −20° C. In embodiments, the base stock of the present application has a CCS at −20° C. at a point in a range of 500 cP to 3500 cP. Alternatively, the base stock of the present application has a CCS at −20° C. at a point in a range of 500 cP to 1500 cP, at a point 1500 cP to 2500 cP, at a point 2500 cP to 3000 cP, or any ranges therebetween.

[0055]In embodiments, the base stock of the present application has a carbon residue as measured according to ASTM D4530-15 (2020) at a point in a range of 0.001 wt. % to 0.025 wt. %. Alternatively, at a point in a range of 0.001 wt. % to 0.010 wt. %., at a point in a range of 0.010 wt. % to 0.020 wt. %., at a point in a range of 0.020 wt. % to 0.025 wt. %., or at a point in a range of any ranges therebetween.

[0056]Petroleum product color serves as an indication of the degree of refinement of the petroleum product. Color is determined according to ASTM D6045-20 (Saybolt color) which has a range of 0 to +30. In embodiments, the base stock of the present application has a Saybolt color of 25-30 and/or +30.

[0057]In embodiments, the base stock of the present application has a saturates content as measured according to ASTM D7419-18 of greater than 90 wt. %. Alternatively, the base stock of the present application has a saturates content of greater than 95 wt. % or greater than 99 wt. %.

[0058]In embodiments, the base stock of the present application has a total sulfur content of less than 5 parts per million (ppm) such as in a range of 0 ppm to 5 ppm as measured according to ASTM D2622-21. Alternatively, at a point in a range of 0 ppm to 1 ppm, a point in a range of 1 ppm to 3 ppm, a point in a range of 3 ppm to 5 ppm, or a point in a range of any ranges therebetween.

[0059]In embodiments, the base stock of the present application is essentially free of metal contaminants, such as having metals below detection limits as measured according to ASTM D5185. Alternatively, the base stock of the present application has a contaminant content below detection limits.

Lubricant Compositions

[0060]In embodiments, the base stock of the present application is included in a lubricant composition. A base stock constitutes the major component of the engine or other mechanical component oil lubricant composition of the present disclosure and typically is present in an amount from about 50 to about 99 weight percent, preferably from about 70 to about 95 weight percent, and more preferably from about 85 to about 95 weight percent, based on the total weight of the composition. As described herein, additives constitute the minor component of the engine or other mechanical component oil lubricant composition of the present disclosure and typically are present in an amount ranging from about less than 50 weight percent, preferably less than about 30 weight percent, and more preferably less than about 15 weight percent, based on the total weight of the composition.

[0061]Mixtures of base stocks may be used if desired, for example, a base stock component and a co-base stock component. The co-base stock component is present in the lubricating oils of this disclosure in an amount from about 1 to about 99 weight percent, preferably from about 5 to about 95 weight percent, and more preferably from about 10 to about 90 weight percent, based on the total weight of the composition. The base stock blend can be present in the engine or other mechanical component oil lubricant composition from 15 wt. % to 99 wt. %, based on the total weight of the oil lubricant composition. Alternatively, from 15 wt. % to 30 wt. %, 30 wt. % to 60 wt. %, 60 wt. % to 80 wt. %, 80 wt. % to 90 wt. %, 90 wt. % to 95 wt. %, 95 wt. % to 99 wt. %, or any ranges therebetween.

[0062]In embodiments, the base stocks further include an additional base stock such as a group I, group II, group III, group IV, group V, or combinations thereof. In embodiments, the additional base stock is present in an amount of 1 wt. % to 99 wt. % by weight of the base stock. Alternatively, from 1 wt. % to 20 wt. %, 20 wt. % to 50 wt. %, 50 wt. % to 70 wt. %, 70 wt. % to 99 wt. %, or any ranges therebetween.

[0063]The formulated lubricating oil useful in the present disclosure may contain one or more of the other commonly used lubricating oil performance additives including but not limited to antiwear additives, detergents, dispersants, viscosity modifiers, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure agents, wax modifiers, other viscosity modifiers, fluid-loss additives, seal compatibility agents, lubricity agents, anti-staining agents, chromophoric agents, anti-foam agents, antioxidants, anti-rust additives, anti-wear additives, pour point depressant, demulsifiers, emulsifiers, densifiers, wetting agents, gelling agents, tackiness agents, colorants, and others. These additives are commonly delivered with varying amounts of diluent oil that may range from 5 weight percent up to greater than 90 weight percent.

[0064]When lubricating oil compositions contain one or more additives, the additive(s) are blended into the composition in an amount sufficient for it to perform its intended function. As stated above, additives are typically present in lubricating oil compositions as a minor component, typically in an amount of less than 50 weight percent, preferably less than about 30 weight percent, and more preferably less than about 15 weight percent, based on the total weight of the composition. Additives are most often added to lubricating oil compositions in an amount of at least 0.1 weight percent, preferably at least 1 weight percent, more preferably at least 5 weight percent.

[0065]The lube base stocks and lubricant compositions can be employed in the present disclosure in a variety of lubricant-related end uses, such as a lubricant oil or grease for a device or apparatus requiring lubrication of moving and/or interacting mechanical parts, components, or surfaces. Useful apparatuses include engines and machines. The lube base stocks of the present disclosure are suitable for use in the formulation of automotive crank case lubricants, automotive gear oils, transmission oils, many industrial lubricants including circulation lubricant, industrial gear lubricants, grease, compressor oil, pump oils, refrigeration lubricants, hydraulic lubricants and metal working fluids. Furthermore, the lube base stocks of this disclosure may be derived from renewable sources; such base stocks may qualify as sustainable product and can meet “sustainability” standards set by industry groups or government regulations. The lube base stocks and lubricant compositions can be useful to reduce wear between surfaces such as metal surfaces in internal combustion engines, electric motors, crankcases, gearboxes, transmissions, differentials, and other mechanical devices. The base stock or lubricant composition containing the base stock can form a film on the surfaces of mechanical devices to protect the surfaces from wear.

ADDITIONAL EMBODIMENTS

[0089]To facilitate a better understanding of the present invention, the following examples of certain aspects of some embodiments are given. In no way should the following examples be read to limit, or define, the entire scope of the disclosure.

Example

[0090]In this example, a simulation was run using a preprocessed used lubricating oil and VGO feed. The hydroprocessing simulation was done in a model built with a large pilot plant database.

[0091]The simulation targeted improved raffinate yield exiting solvent extraction when targeting a specific VI and/or improve the raffinate quality at the same raffinate yield. The raffinate is subsequently processed in the hydrotreating section followed by a high pressure stripping of H2S and NH3 before being sent to a catalytic dewaxing section. The hydroconverted and dewaxed reactor effluent is hydrofinished and then stripped in a series of separation unit including the vacuum tower to produce a different viscosity group II and/or group III base stock depending on the VGO grade (light, medium, heavy). The results of the simulation are shown in Table 1 and Table 2.

[0092]It was observed that blending the preprocessed used lubricating oil with light VGO at 15% improved the raffinate yield across solvent extraction unit. Properties of preprocessed used lubricating oil and light VGO are shown in Table 1. The blending of the preprocessed lubricating oil at 15% greatly enhanced the raffinate 4 to 9% higher raffinate yield relative to the base case as shown in Table 2. Processing the higher VI raffinate in the downstream hydrotreating and hydrodewaxing/finishing reactors increases the overall base stock yield and production by 6 wt. %.

[0093]While the disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the disclosure as disclosed herein. Although individual embodiments are discussed, the present disclosure covers all combinations of all those embodiments.

[0094]While compositions, methods, and processes are described herein in terms of “comprising,” “containing,” “having,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. The phrases, unless otherwise specified, “consists essentially of” and “consisting essentially of” do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used.

[0095]All numerical values within the detailed description are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0096]Many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description without departing from the spirit or scope of the present disclosure and that when numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.