WO2021028839A1 - Process for improving base oil yields - Google Patents

Abstract

An improved process for making a base oil and for improving base oil yields by combining an atmospheric resid feedstock with a base oil feedstock and forming a base oil product via hydroprocessing. The process generally involves subjecting a base oil feedstream comprising the atmospheric resid to hydrocracking and dewaxing steps, and optionally to hydrofinishing, to produce a light and heavy grade base oil product. A process is also disclosed for making a base oil having a viscosity index of 120 or greater from a base oil feedstock having a viscosity index of about 100 or greater that includes a narrow cut-point range vacuum gas oil. The invention is useful to make Group II and/or Group III/III+ base oils, and, in particular, to increase the yield of a heavy base oil product relative to a light base oil product produced in the process.

Description

PROCESS FOR IMPROVING BASE OIL YIELDS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Appl. Ser. No. 62/885,359, filed on August 12, 2019, the disclosure of which is herein incorporated in its entirety.

FIELD OF THE INVENTION

[0002] The invention concerns a process for improving base oil yields by combining an atmospheric resid feedstock with a base oil feedstock to form a combined feedstream and forming a base oil product therefrom via hydroprocessing.

BACKGROUND OF THE INVENTION

[0003] High quality lubricating base oils, such as those having a viscosity index (VI) of 120 or greater (Group II and Group III), may generally be produced from high-boiling point vacuum distillates, such as vacuum gas oils (VGO), by hydrocracking to raise VI, followed by catalytic dewaxing to lower pour point and cloud point, and followed by hydrofinishing to saturate aromatics and improve stability. In hydrocracking, high-boiling molecules are cracked to lower-boiling molecules which raises VI but also lowers the viscosity. In order to make a high VI and high viscosity grade base oil at high yield, the hydrocracker feed must contain a certain quantity of high-boiling molecules. Typically, VGOs are limited in their ability to recover very high-boiling molecules from atmospheric resid (AR) in a vacuum column because of practical limits on temperature and pressure. One possible means of feeding higher-boiling molecules to the hydrocracker is to feed the AR directly, but such an approach is not normally possible or workable because the AR usually contains materials that are extremely harmful to the hydrocracker catalyst, including, e.g., nickel, vanadium, micro-carbon residue (MCR) and asphaltenes. These materials shorten the hydrocracker catalyst life to an unacceptable degree, making the use of such feeds impracticable.

[0004] One approach to using difficult whole crude and other intermediate feeds for making base oils is to first process the feed, such as AR or vacuum resid (VR), in a solvent deasphalting (SDA) unit. Such treatment is usually necessary to separate the bulk of undesirable materials while producing a deasphalted oil (DAO) of acceptable hydrocracker feed quality. The very high capital requirements and high operating cost of such SDA units, and the overall process approach, make them undesirable alternatives, however. Other approaches that attempt to minimize or eliminate the need for solvent deasphalting steps have been implemented but have not provided a clear benefit in terms of cost or other process improvements. [0005] The production of Group III base oils and finished motor oils has usually required the use of expensive and supply-limited viscosity index improvers such as polyalphaolefins, or other expensive processing techniques, such as the use of gas-to-liquid (GTL) feedstocks or, e.g., through multi-hydrocracking processing of mineral oils. The production of Group III base oils also generally requires high quality feedstock(s) and processing at high conversion to meet a VI targets at the expense of product yield. Despite continuing industry efforts, however, a comparatively inexpensive and suitable feedstock, and a simplified process for making such products, remains to be developed and commercialized.

[0006] Despite the progress in producing base oils from differing and challenging feeds, a continuing need exists for improved processes to both utilize different feedstocks and to increase the yield of valuable base oil products.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to a process for making a base oil product, particularly a light grade base oil product and a heavy grade base oil product through hydroprocessing of a base oil feedstream. While not necessarily limited thereto, one of the goals of the invention is to provide increased base oil yield of a heavy grade base oil product and to the production of Group II and/or Group III/III+ base oils.

[0008] In general, a first process according to the invention comprises making a base oil by combining an atmospheric resid feedstock and a base oil feedstock to form a base oil feedstream; contacting the base oil feedstream with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and, optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product.

[0009] The invention also relates to a method for modifying a base oil process through the addition of an atmospheric resid feedstock to a base oil feedstock in a conventional base oil process that comprises subjecting a base oil feedstream to hydrocracking and dewaxing steps to form a dewaxed product comprising a light product and a heavy product. As such, the modified base oil process comprises combining an atmospheric resid feedstock and a base oil feedstock to form a base oil feedstream; contacting the base oil feedstream with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into at least a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and, optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product.

[0010] A second process according to the invention comprises making a base oil having a viscosity index of 120 or greater by contacting a base oil feedstock having a viscosity index of about 100 or greater that comprises a medium vacuum gas oil (MVGO) having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into a gaseous fraction and a liquid fraction; dewaxing of the liquid fraction to produce a dewaxed product; and optionally, hydrofinishing of the dewaxed product to produce a hydrofinished dewaxed product.

[0011] The invention further relates to a combined process for making a base oil product from a base oil feedstock that combines the first process and the second process to make base oils meeting Group II and/or Group III/III+ specifications. The combined process generally provides for making a base oil from a base oil feedstock, or a fraction thereof, and includes the use of an atmospheric resid fraction from a base oil feedstock, or a fraction thereof; separation of the base oil feedstock, or a fraction thereof, and/or the base oil atmospheric resid fraction into a narrow vacuum gas oil cut-point fraction having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less to form a medium vacuum gas oil (MVGO) fraction and a residual heavy VGO (HHVGO) fraction; and use of the HHVGO fraction as the atmospheric resid feedstock in the first process; and/or use of the MVGO fraction as the base oil feedstock in the second process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The scope of the invention is not limited by any representative figures accompanying this disclosure and is to be understood to be defined by the claims of the application.

[0013] FIG. 1 is a general block diagram schematic illustration of a prior art process to make a base oil product.

[0014] FIG. 2a is a general block diagram schematic illustration of an embodiment of a process to make a base oil product using a blend of VGO and atmospheric resid (VGO/AR) according to the invention.

[0015] FIG. 2b is a general block diagram schematic illustration of an embodiment of a process to make a Group III/III+ base oil product using an MVGO fraction from an atmospheric resid and a Group II base oil product using a blend of VGO and an HHVGO residual fraction from an atmospheric resid (VGO/HHVGO) according to the invention. [0016] FIG. 3a is a process schematic illustration of an embodiment of a process to make a base oil product according to the invention, as described in the examples.

[0017] FIG. 3b is a process schematic illustration of an embodiment of a process to make a base oil product according to the invention, as described in the examples.

[0018] FIG. 4 is a process schematic illustration of an embodiment of a process to make a base oil product according to the invention, as described in the examples.

[0019] FIG. 5 is a process schematic illustration of an embodiment of a process to make a base oil product according to the invention, as described in the examples.

DETAILED DESCRIPTION

[0020] Although illustrative embodiments of one or more aspects are provided herein, the disclosed processes may be implemented using any number of techniques. The disclosure is not limited to the illustrative or specific embodiments, drawings, and techniques illustrated herein, including any exemplary designs and embodiments illustrated and described herein, and may be modified within the scope of the appended claims along with their full scope of equivalents.

[0021] Unless otherwise indicated, the following terms, terminology, and definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the lUPAC Compendium of Chemical Terminology, 2nd ed (1997), may be applied, provided that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein is to be understood to apply.

[0022] "API Base Oil Categories" are classifications of base oils that meet the different criteria shown in Table 1:

Table 1: Base Oil Stock Properties (4 cSt @100°C viscosity stocks, no additives)

[0023] "API gravity" refers to the gravity of a petroleum feedstock or product relative to water, as determined by ASTM D4052-11 or ASTM D1298.

[0024] "ISO-VG" refers to the viscosity classification that is recommended for industrial applications, as defined by IS03448:1992.

[0025] "Viscosity index" (VI) represents the temperature dependency of a lubricant, as determined by ASTM D2270-10(E2011).

[0026] "Aromatic Extraction" is part of a process used to produce solvent neutral base oils. During aromatic extraction, vacuum gas oil, deasphalted oil, or mixtures thereof are extracted using solvents in a solvent extraction unit. The aromatic extraction creates a waxy raffinate and an aromatic extract, after evaporation of the solvent.

[0027] "Atmospheric resid" or "atmospheric residuum" (AR) is a product of crude oil distillation at atmospheric pressure in which volatile material has been removed during distillation. AR cuts are typically derived at 650°F up to a 680°F cut point.

[0028] "Vacuum gas oil" (VGO) is a byproduct of crude oil vacuum distillation that can be sent to a hydroprocessing unit or to an aromatic extraction for upgrading into base oils. VGO generally comprises hydrocarbons with a boiling range distribution between 343°C (649°F) and 538°C (1000°F) at 0.101 MPa.

[0029] "Deasphalted oil" (DAO) generally refers to the residuum from a vacuum distillation unit that has been deasphalted in a solvent deasphalting process. Solvent deasphalting in a refinery is described in J. Speight, Synthetic Fuels Handbook, ISBN 007149023X, 2008, pages 64, 85-85, and 121

[0030] "Treatment," "treated," "upgrade," "upgrading" and "upgraded," when used in conjunction with an oil feedstock, describes a feedstock that is being or has been subjected to hydroprocessing, or a resulting material or crude product, having a reduction in the molecular weight of the feedstock, a reduction in the boiling point range of the feedstock, a reduction in the concentration of asphaltenes, a reduction in the concentration of hydrocarbon free radicals, and/or a reduction in the quantity of impurities, such as sulfur, nitrogen, oxygen, halides, and metals.

[0031] "Solvent Dewaxing" is a process of dewaxing by crystallization of paraffins at low temperatures and separation by filtration. Solvent dewaxing produces a dewaxed oil and slack wax. The dewaxed oil can be further hydrofinished to produce base oil.

[0032] "Hydroprocessing" refers to a process in which a carbonaceous feedstock is brought into contact with hydrogen and a catalyst, at a higher temperature and pressure, for the purpose of removing undesirable impurities and/or converting the feedstock to a desired product. Examples of hydroprocessing processes include hydrocracking, hydrotreating, catalytic dewaxing, and hyd rofinishing.

[0033] "Hydrocracking" refers to a process in which hydrogenation and dehydrogenation accompanies the cracking/fragmentation of hydrocarbons, e.g., converting heavier hydrocarbons into lighter hydrocarbons, or converting aromatics and/or cycloparaffins (naphthenes) into non- cyclic branched paraffins.

[0034] "Hydrotreating" refers to a process that converts sulfur and/or nitrogen-containing hydrocarbon feeds into hydrocarbon products with reduced sulfur and/or nitrogen content, typically in conjunction with hydrocracking, and which generates hydrogen sulfide and/or ammonia (respectively) as byproducts.

[0035] "Catalytic dewaxing", or hydroisomerization, refers to a process in which normal paraffins are isomerized to their more branched counterparts in the presence of hydrogen and over a catalyst.

[0036] "Hydrofinishing" refers to a process that is intended to improve the oxidation stability, UV stability, and appearance of the hydrofinished product by removing traces of aromatics, olefins, color bodies, and solvents. As used in this disclosure, the term UV stability refers to the stability of the hydrocarbon being tested when exposed to UV light and oxygen. Instability is indicated when a visible precipitate forms, usually seen as Hoc or cloudiness, or a darker color develops upon exposure to ultraviolet light and air. A general description of hydrofinishing may be found in U.S. Patent Nos. 3,852,207 and 4,673,487.

[0037] The term "Hydrogen" or "hydrogen" refers to hydrogen itself, and/or a compound or compounds that provide a source of hydrogen.

[0038] "Cut point" refers to the temperature on a True Boiling Point (TBP) curve at which a predetermined degree of separation is reached.

[0039] "TBP" refers to the boiling point of a hydrocarbonaceous feed or product, as determined by Simulated Distillation (SimDist) by ASTM D2887-13. [0040] "Hydrocarbonaceous", "hydrocarbon" and similar terms refer to a compound containing only carbon and hydrogen atoms. Other identifiers may be used to indicate the presence of particular groups, if any, in the hydrocarbon (e.g., halogenated hydrocarbon indicates the presence of one or more halogen atoms replacing an equivalent number of hydrogen atoms in the hydrocarbon).

[0041] "Group MB" or "Group MB metal" refers to zinc (Zn), cadmium (Cd), mercury (Hg), and combinations thereof in any of elemental, compound, or ionic form.

[0042] "Group IVA" or" "Group IVA metal" refers to germanium (Ge), tin (Sn) or lead (Pb), and combinations thereof in any of elemental, compound, or ionic form.

[0043] "Group V metal" refers to vanadium (V), niobium (Nb), tantalum (Ta), and combinations thereof in their elemental, compound, or ionic form.

[0044] "Group VI B" or "Group VIB metal" refers to chromium (Cr), molybdenum (Mo), tungsten (W), and combinations thereof in any of elemental, compound, or ionic form.

[0045] "Group VIII" or "Group VIII metal" refers to iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhenium (Rh), rhodium (Ro), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), and combinations thereof in any of elemental, compound, or ionic form.

[0046] The term "support", particularly as used in the term "catalyst support", refers to conventional materials that are typically a solid with a high surface area, to which catalyst materials are affixed. Support materials may be inert or participate in the catalytic reactions, and may be porous or non-porous. Typical catalyst supports include various kinds of carbon, alumina, silica, and silica-alumina, e.g., amorphous silica aluminates, zeolites, alumina-boria, silica-alumina-magnesia, silica-alumina-titania and materials obtained by adding other zeolites and other complex oxides thereto.

[0047] "Molecular sieve" refers to a material having uniform pores of molecular dimensions within a framework structure, such that only certain molecules, depending on the type of molecular sieve, have access to the pore structure of the molecular sieve, while other molecules are excluded, e.g., due to molecular size and/or reactivity. Zeolites, crystalline aluminophosphates and crystalline silicoaluminophosphates are representative examples of molecular sieves.

[0048] W220 and W600 refer to waxy medium and heavy Group II base oil product grades, with

W220: referring to a waxy medium base oil product having a nominal viscosity of about 6 cSt at 100°C, and W600: referring to a waxy heavy base oil product having a nominal viscosity of about 12 cSt at 100°C. Following dewaxing, typical test data for Group II base oils are as follows:

Property Standard Test 220N 600 N API Base Stock Category (API 1509 E.1.3) Group II Group II API Gravity ASTM D1298 32.1 31.0

Specific Gravity at 60/60°F ASTM D1298 0.865 0.871 Density, Ib/gal ASTM D1298 7.202 7.251 Viscosity, Kinematic ASTM D445 cSt at 40°C 41.0 106 cSt at 100°C 6.3 12.0 Viscosity, Saybolt ASTM D2161 212 530 SUS at 100°F Viscosity Index ASTM D2270 102 102 Pour Point, °C ASTM D97 -15 -15

Evaporation Loss, NOACK, wt % CEC-L-40-A-93 11 2 Flash Point, COC, °C ASTM D92 230 265 Color ASTM D1500 L 0.5 L 0.5

Sulfur, ppm Chevron <6 <6 Water, ppm ASTM D1744 <50 <50 Saturates, FIPLC, wt % Chevron >99 >99 Aromatics, FIPLC, wt % Chevron <1 <1

[0049] In this disclosure, while compositions and methods or processes are often described in terms of "comprising" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" the various components or steps, unless stated otherwise. [0050] The terms "a," "an," and "the" are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of "a transition metal" or "an alkali metal" is meant to encompass one, or mixtures or combinations of more than one, transition metal or alkali metal, unless otherwise specified.

[0051] All numerical values within the detailed description and the claims herein are modified by "about" or "approximately" the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0052] In one aspect, the present invention is a process for making a base oil product, comprising combining an atmospheric resid feedstock and a base oil feedstock to form a base oil feedstream; contacting the base oil feedstream with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product. [0053] The base oil feedstock generally meets one or more of the following property conditions:

API gravity in the range of 15-40 or 15-30 or 15-25, or at least 15, or at least 17, optionally, less than the atmospheric resid feedstock;

VI in the range of 30-90 or 40-90 or 50-90 or 50-80, optionally, less than the VI of the atmospheric resid feedstock; viscosity at 100°C in the range of 3-30 cSt or 3-25 cSt or 3-20 cSt, or at least 3 cSt, or at least 4 cSt; viscosity at 70°C in the range of 5-25 cSt or 5-20 cSt or 5-15 cSt, or at least 5 cSt, or at least 6 cSt; hot C₇ asphaltene content in the range of 0.01-0.3 wt.% or 0.01-0.2 wt.% or 0.02-0.15 wt.%, or less than 0.3 wt. %, or less than 0.2 wt.%; wax content in the range of 5-40 wt.% or 5-30 wt.% or 10-25 wt.%, or at least 5 wt.% or at least 10 wt.%, or at least 15 wt.%, or, optionally, greater than the wax content of the base oil feedstock; nitrogen content of less than 2500 ppm or less than 2000 ppm or less than 1500 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm or less than 100 ppm; sulfur content of less than 8000 ppm or less than 6000 ppm or less than 4000 ppm or less than 2000 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm, or in the range of 100-8000 ppm or 100-6000 ppm or 100-4000 ppm or 100-2000 ppm or 100-1000 ppm or 100-500 ppm or 100-200 ppm; and/or

1050+°F content in the range of 5-50 wt.% or 5-40 wt.% or 8-40 wt.%, or, optionally, greater than the 1050+°F content of the base oil feedstock.

[0054] Suitable base oil feedstocks may be from any crude oil feedstock, or a fraction thereof, including hydroprocessed intermediate streams or other feeds. Generally, the base oil feedstock contains materials boiling within the base oil range. Feedstocks may include atmospheric and vacuum residuum from a variety of sources, whole crudes, and paraffin-based crudes.

[0055] The atmospheric resid (AR) feedstock generally meets one or more of the following property conditions:

API gravity in the range of 20-60 or 20-45 or 25-45, or at least 20, or at least 22, or, optionally, greater than the API of the base oil feedstock;

VI in the range of 50-200 or 70-190 or 90-180, or at least 80, or, optionally, greater than the VI of the base oil feedstock; viscosity at 100°C in the range of 3-30 cSt or 3-25 cSt or 3-20 cSt, or at least 3 cSt, or at least 4 cSt; viscosity at 70°C in the range of 5-25 cSt or 5-20 cSt or 5-15 cSt, or at least 5cSt, or at least 6 cSt; hot C₇ asphaltene content in the range of 0.01-0.3 wt.% or 0.01-0.2 wt.% or 0.02-0.15 wt.%, or less than 0.3 wt. %, or less than 0.2 wt.%; wax content in the range of 5-40 wt.% or 5-30 wt.% or 10-25 wt.%, or at least 5 wt.% or at least 10 wt.%, or at least 15 wt.%, or, optionally, greater than the wax content of the base oil feedstock; nitrogen content of less than 2500 ppm or less than 2000 ppm or less than 1500 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm or less than 100 ppm; sulfur content of less than 8000 ppm or less than 6000 ppm or less than 4000 ppm or less than 2000 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm, or in the range of 100-8000 ppm or 100-6000 ppm or 100-4000 ppm or 100-2000 ppm or 100-1000 ppm or 100-500 ppm or 100-200 ppm; and/or

1050+°F content in the range of 5-50 wt.% or 5-40 wt.% or 8-40 wt.%, or, optionally, greater than the 1050+°F content of the base oil feedstock.

[0056] In some aspects, AR feedstocks having property characteristics described herein may be advantageously derived from a light tight oil (LTO, e.g., shale oil typically having an API of >45). Suitable feedstocks may be Permian Basin feedstocks and elsewhere, including Eagle Ford, Avalon, Magellan, Buckeye, and the like.

[0057] Both the base oil feedstock and the atmospheric resid feedstock may have any of the foregoing properties within any of the noted broad and narrower ranges and combinations of such ranges.

[0058] The base oil feedstream generally comprises 10--60 wt.% atmospheric resid feedstock and 40-90 wt.% base oil feedstock, or 10-40 wt.% atmospheric resid feedstock and 60-90 wt.% base oil feedstock, or 10-30 wt.% atmospheric resid feedstock and 70-90 wt.% base oil feedstock, or 30-60 wt.% atmospheric resid feedstock and 40-70 wt.% base oil feedstock, or 40-60 wt.% atmospheric resid feedstock and 40--60 wt.% base oil feedstock.

[0059] In certain embodiments, the base oil feedstream does not contain an added whole crude oil feedstock, and/or does not contain a vacuum residue feedstock, and/or does not contain a deasphalted oil feedstock component, and/or contains only atmospheric resid feedstock and base oil feedstock. [0060] While not limited to a straight run process, the process need not include recycle of a liquid feedstock as part of the base oil feedstream or as either or both of the atmospheric resid feedstock and the base oil feedstock. In certain embodiments, recycle of one or more intermediate streams may be desired, however.

[0061] The base oil feedstock may comprise vacuum gas oil, or consist essentially of vacuum gas oil, or consist of vacuum gas oil. The vacuum gas oil may be a heavy vacuum gas oil obtained from vacuum gas oil that is cut into a light fraction and a heavy fraction, with the heavy fraction having a cut point temperature range of about 950-1050°F.

[0062] The dewaxed product and/or the hydrofinished dewaxed product is typically obtained as a light base oil product and a heavy base oil product. The light base oil product generally has a nominal viscosity in the range of 4-8 cSt or 5-7 cSt at 100°C and/or with the heavy base oil product generally having a nominal viscosity in the range of 10-14 cSt or 11-13 cSt at 100°C. The dewaxed product may be further separated into at least a light product having a nominal viscosity of about 6 cSt at 100°C, and/or at least a heavy product having a nominal viscosity of about 12 cSt at 100°C, or a combination thereof.

[0063] One of the advantages associated with the process is that the yield of the heavy base oil product relative to the light base oil product may be increased by at least about 2 Lvol.%, or at least about 5 Lvol.% (liquid volume %) compared with the same process that does not include the atmospheric resid feedstock in the lubricating oil feedstream. In some embodiments, the yield of the heavy base product may be increased by at least about 10 Lvol.%, or at least about 20 Lvol.%, or at least about 30 Lvol.%, or at least about 40 Lvol.%, compared with the same process that does not include the atmospheric resid feedstock in the base oil feedstream.

[0064] In another aspect, the invention concerns a method for modifying a conventional or existing base oil process. In particular, a base oil process that comprises subjecting a base oil feedstream to hydrocracking and dewaxing steps to form a dewaxed product comprising a lighter product and a heavier product may be modified according to the invention by combining an atmospheric resid feedstock with a base oil feedstock to form the base oil feedstream and subjecting the base oil feedstream comprising the atmospheric resid feedstock to the hydrocracking and dewaxing steps of the base oil process to produce a dewaxed product. The dewaxed product may be optionally further contacted with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product.

[0065] The invention further relates to a process for making a base oil, comprising contacting a base oil feedstock having a viscosity index of about 100 or greater with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product, wherein the base oil feedstock comprises vacuum gas oil having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less; separating the hydrocracked product into a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product; wherein, the dewaxed product and/or the hydrofinished dewaxed product has a viscosity index of 120 or greater after dewaxing. The dewaxed product and/or the hydrofinished dewaxed product may have a viscosity index of 130 or greater after dewaxing, or 135 or greater after dewaxing, or 140 or greater after dewaxing. The hydrocracked product may have a viscosity index of at least about 135, or 140, or 145, or 150. The dewaxed products prepared by the process may be a Group III or Group 111+ product.

[0066] By comparison to the use of a conventional VGO feedstock, the use of a vacuum gas oil having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less, herein referred to as a medium vacuum gas oil (MVGO) provides an improved waxy product yield at a Group III or Group 111+ viscosity of 4cSt 100°C of the MVGO that is at least about 3 lvol.% greater than the same process that does not include the MVGO as the base oil feedstock. [0067] The invention further relates to a process that combines the two process aspects, i.e., in which a feedstock is used to derive the narrow cut-point fraction and the same or a different feedstock is used for the atmospheric resid fraction. The combined process for making a base oil from a base oil feedstock, or a fraction thereof, comprises providing an atmospheric resid fraction from a base oil feedstock, or a fraction thereof; separating the base oil feedstock, or a fraction thereof, and/or the base oil atmospheric resid fraction into a narrow vacuum gas oil cut- point fraction having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less to form an MVGO fraction and a residual FIFIVGO fraction; using the FIFIVGO fraction as the atmospheric resid feedstock in the first process to prepare a dewaxed product and/or hydrofinished dewaxed product; and/or using the MVGO fraction as the base oil feedstock in a second process to prepare a dewaxed product and/or hydrofinished dewaxed product having a viscosity index of 120 or greater after dewaxing. In certain embodiments, the base oil feedstock may comprise tight oil, particularly a light tight oil, or a fraction thereof. The narrow vacuum gas oil cut- point fraction may also be derived from the atmospheric resid fraction, including an atmospheric resid fraction derived from light tight oil.

[0068] Advantageously, the fractionation of the AR feedstock into MVGO and FIFIVGO fractions provides the ability to produce Group III/III+ base oil product while still allowing the FIFIVGO fraction to be used with a conventional VGO base oil feedstock to produce a Group II base oil product. In some embodiments, the use of MVGO to produce Group III/III+ base oil product results in greater yields of such products.

[0069] An illustration of a method or process according to an embodiment of the invention is shown schematically in FIG. 2a, in which conventional base oil hydrotreating, hydrocracking, hydrodewaxing, and hydrofinishing process steps, conditions, and catalysts are used. By comparison to a prior art base oil process schematic illustrated in FIG 1, FIG. 2a shows the use of a feed blend of VGO and atmospheric resid (AR) where the conventional process typically uses VGO base oil feedstock. FIG 2b further illustrates the use of an AR feedstock to form a medium vacuum gas oil fraction (MVGO) and a heavy VGO fraction (FIFIVGO), with the MVGO fraction feedstream being used to produce a Group III/III+ base oil product and the FIFIVGO fraction feedstream being combined with a conventional VGO base oil feedstock to produce a Group II base oil product.

[0070] Catalysts suitable for use as the hydrocracking, dewaxing, and hydrofinishing catalysts in the process and method and associated process conditions are described in a number of publications, including, e.g., US Patent Publication Nos. 3,852,207; 3,929,616; 6,156,695; 6,162,350; 6,274,530;6,299,760; 6,566,296; 6,620,313; 6,635,599; 6,652,738;6,758,963; 6,783,663; 6,860,987; 7,179,366; 7,229,548;7,232,515; 7,288,182; 7,544,285, 7,615,196; 7,803,735;7,807,599; 7,816,298; 7,838,696; 7,910,761; 7,931,799; 7,964,524; 7,964,525; 7,964,526; 8,058,203; 10,196,575;

WO 2017/044210; and others.

[0071] Catalysts suitable for hydrocracking, e.g., comprise materials having hydrogenation- dehydrogenation activity, together with an active cracking component support. Such catalysts are well described in many patent and literature references. Exemplary cracking component supports include silica-alumina, silica- oxide zirconia composites, acid-treated clays, crystalline aluminosilicate zeolitic molecular sieves such as zeolite A, faujasite, zeolite X, and zeolite Y, and combinations thereof. Flydrogenation-dehydrogenation components of the catalyst preferably comprise a metal selected from Group VIII metals and compounds thereof and Group VIB metals and compounds thereof. Preferred Group VIII components include cobalt and nickel, particularly the oxides and sulfides thereof. Preferred Group VIB components are the oxides and sulfides of molybdenum and tungsten. Examples of a hydrocracking catalyst which would be suitable for use in the hydrocracking process step are the combinations of nickel-tungsten-silica-alumina, nickel- molybdenum-silica-alumina and cobalt-molybdenum-silica-alumina. Such catalysts may vary in their activities for hydrogenation and for cracking and in their ability to sustain high activity during long periods of use depending on their compositions and preparation. [0072] Typical hydrocracking reaction conditions include, for example, a temperature of from 450°F to 900° F (232°C to 482°C), e.g., from 650°F to 850°F (343°C to 454°C); a pressure of from 500 psig to 5000 psig (3.5 MPa to 34.5 MPa gauge), e.g., from 1500 psig to 3500 psig (10.4 MPa to 24.2 MPa gauge); a liquid reactant feed rate, in terms of liquid hourly space velocity (LHSV) of from 0.1 hr ¹ to 15 hr ¹ (v/v), e.g., from 0.25 hr ¹ to 2.5 hr ¹; a hydrogen feed rate, in terms of H₂/hydrocarbon ratio, of from 500 SCF/bbl to 5000 SCF/bbl (89 to 890 m³ H₂/m³ feedstock) of liquid base oil (lubricating) feedstock, and/or a hydrogen partial pressure of greater than 200 psig, such as from 500 to 3000 psig; and hydrogen re-circulation rates of greater than 500 SCF/B, such as between 1000 and 7000 SCF/B.

[0073] Hydrodewaxing is used primarily for reducing the pour point and/or for reducing the cloud point of the base oil by removing wax from the base oil. Typically, dewaxing uses a catalytic process for processing the wax, with the dewaxer feed is generally upgraded prior to dewaxing to increase the viscosity index, to decrease the aromatic and heteroatom content, and to reduce the amount of low boiling components in the dewaxer feed. Some dewaxing catalysts accomplish the wax conversion reactions by cracking the waxy molecules to lower molecular weight molecules. Other dewaxing processes may convert the wax contained in the hydrocarbon feed to the process by wax isomerization, to produce isomerized molecules that have a lower pour point than the non- isomerized molecular counterparts. As used herein, isomerization encompasses a hydroisomerization process, for using hydrogen in the isomerization of the wax molecules under catalytic hydroisomerization conditions.

[0074] Dewaxing generally includes processing the dewaxer feedstock by hydroisomerization to convert at least the n-paraffins and to form an isomerized product comprising isoparaffins. Suitable isomerization catalysts for use in the dewaxing step can include, but are not limited to, Pt and/or Pd on a support. Suitable supports include, but are not limited to, zeolites CIT-1, IM-5, SSZ-20,SSZ- 23,SSZ-24, SSZ-25,SSZ-26, SSZ-31, SSZ-32, SSZ-32,SSZ-33,SSZ-35, SSZ-36,SSZ-37, SSZ-41, SSZ -42, SSZ- 43, SSZ-44, SSZ-46, SSZ-47, SSZ-48, SSZ-51, SSZ-56, SSZ-57, SSZ-58, SSZ-59, SSZ-60, SSZ-61, SSZ-63, SSZ- 64, SSZ-65, SSZ-67, SSZ-68, SSZ-69, SSZ-70, SSZ-71, SSZ-74, SSZ-75, SSZ-76, SSZ-78, SSZ-81, SSZ- 82, SSZ-83, SSZ-86, SUZ-4, TNU-9, ZSM-S, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, EMT-type zeolites, FAU-type zeolites, FER-type zeolites, MEL-type zeolites, MFI-type zeolites, MTT-type zeolites, MTW-type zeolites, MWW-type zeolites, MRE-type zeolites, TON-type zeolites, other molecular sieves materials based upon crystalline aluminophosphates such as SM-3, SM-7, SAPO-II, SAPO-31, SAPO-41, MAPO-II and MAPO-31. Isomerization may involve also a Pt and/or Pd catalyst supported on an acidic support material such as beta or zeolite Y molecular sieves, silica, alumina, silica-alumina, and combinations thereof. Suitable isomerization catalysts are well described in the patent literature, see, e.g., US. Pat. Nos. 4,859,312; 5,158,665; and 5,300,210.

[0075] Hydrodewaxing conditions generally depend on the feed used, the catalyst used, whether or not the catalyst is sulfided, the desired yield, and the desired properties of the base oil. Typical conditions include a temperature of from 500°F to 775°F (260°C to 413°C); a pressure of from 15 psig to 3000 psig (0.10 MPa to 20.68 MPa gauge); a LHSV of from 0.25 hr¹ to 20 hr ¹; and a hydrogen to feed ratio of from 2000 SCF/bbl to 30,000 SCF/bbl (356 to 5340 m³ H₂/m³ feed). Generally, hydrogen will be separated from the product and recycled to the isomerization zone. Suitable dewaxing conditions and processes are described in, e.g., U.S. Pat. Nos. 5,135,638; 5,282,958; and 7,282,134.

[0076] Waxy products W220 and W600 may be dewaxed to form 220N and 600N products that may be suitable (or better suited) for use as a lubricating base oil or in a lubricant formulation. For example, the dewaxed product may be mixed or admixed with existing lubricating base oils in order to create new base oils or to modify the properties of existing base oils, e.g., to meet particular target conditions, such as viscometric or Noack target conditions, for particular base oil grades like 220N and 600N. Isomerization and blending can be used to modulate and maintain pour point and cloud point of the base oil at suitable values. Normal paraffins may also be blended with other base oil components prior to undergoing catalytic isomerization, including blending normal paraffins with the isomerized product. Lubricating base oils that may be produced in the dewaxing step may be treated in a separation step to remove light product. The lubricating base oil may be further treated by distillation, using atmospheric distillation and optionally vacuum distillation to produce a lubricating base oil.

[0077] Typical hydrotreating conditions vary over a wide range. In general, the overall LHSV is about 0.25 hr ¹ to 10 hr¹ (v/v), or alternatively about 0.5 hr ¹ to 1.5 hr ¹. The total pressure is from 200 psig to 3000 psig, or alternatively ranging from about 500 psia to about 2500 psia. Hydrogen feed rate, in terms of H₂/hydrocarbon ratio, are typically from 500 SCF/Bbl to 5000SCF/bbl (89 to 890 m³ H₂/m³ feedstock), and are often between 1000 and 3500 SCF/Bbl. Reaction temperatures in the reactor will typically be in the range from about 300°F to about 750°F (about 150°C to about 400°C), or alternatively in the range from 450°F to 725°F (230°C to 385°C).

[0078] In practice, layered catalyst systems may be used comprising hydrotreating (HDT, HDM, DEMET, etc.), hydrocracking (HCR), hydrodewaxing (HDW), and hydrofinishing (HFN) catalysts to produce intermediate and/or finished base oils using single or multireactor systems. A typical configuration includes two reactors with the first reactor comprising layered catalysts providing DEMET, HDT pretreatment, HCR, and/or HDW activity. Differing catalysts performing similar functions, e.g., different levels of hydrocracking activity, may be used as well, e.g., in different layers within a single reactor or in separate reactors.

EXAMPLES

[0079] Samples of vacuum gas oil (VGO) and atmospheric resid (AR) were obtained from commercially available sources and used in the process schemes illustrated in FIG's. 3a, 3b, 4, and 5. FIG's 3a and 3b show larger process research unit configurations that were generally used to evaluate larger quantities of feedstocks when available. FIG's 4 and 5 show smaller bench scale units used to evaluate smaller feedstocks quantities and were primarily used to evaluate all AR samples.

[0080] Research unit process conditions used included 0.5 LHSV ^_1, reactor FL partial pressure of 1750 psia, hydrogen feed gas oil (recycle) ratio of 4500 scfb, and reactor temperatures in range of 700-770+°F, with the downstream reactor R2 temperature being maintained at 20°F hotter than the upstream R1 reactor. An ascending temperature profile was imposed, 120°F and 40°F DT for R1 and R2, respectively. Waxy product target viscosity indexes (Vi's) were set at 109 at 6.0 cSt at 100°C (W220) and 11.8 cSt at 100°C (W600).

[0081] Bench scale process conditions used included 0.5 LHSV ¹, reactor pressure of 1850 psig, hydrogen feed gas oil ratio of 4500 scfb, and reactor temperatures in range of 700-770+°F, with the downstream reactor R2 temperature being maintained at 20°F hotter than the upstream R1 reactor. Waxy product target viscosity indexes (Vi's) were set at 109 at 6.1 cSt at 100°C (220R) and 11.8 cSt at 100°C (600R).

[0082] The catalyst loading in each of reactors R1 and R2 (according to each of FIG's 3a, 3b, 4, and 5) was a conventional scheme for base oil production comprising layered hydrometallation, hydrotreating, and hydrocracking catalysts. Typical configurations included layered catalyst systems comprising one or more DEMET layers, high activity HCR/H DT, HCR, and low activity HCR catalysts for both R1 and R2.

[0083] FIG's 3a, 3b, 4, and 5 each show feedstreams 10 and Fh inlet 11 to each of reactors R1 and R2, and other intermediate flow streams 20, 30, FL recycle stream 31, whole liquid product (WLP) stream 32 that are sent to separators and/or condensers (Cl to C4, SI, and V3) to provide the respective product streams C2B, C3B, C40, C4B, STO, STB, V30, and V3B shown in each figure and as noted in the following examples.

Example 1 - Vacuum Gas Oil (VGO) Feedstock (comparative feedstock)

[0084] A sample of vacuum gas oil (VGO) feedstock from a commercially available source used to produce base oil products was obtained and analyzed as a comparative base case. The VGO feedstock was used in the following examples according to the process configurations shown in FIG's. 3a, 3b, 4, and 5. The properties of this VGO feedstock (sample ID 2358) are shown in Table 1.

Table 1 - Properties of Vacuum Gas Oil (VGO) Feedstock

Feed VGO

Property Property Value

API Gravity 18

Viscosity Index, VI (D2270) 52 Viscosity, 100°C (cSt) 13.23 Viscosity, 70°C (cSt) 37.56

Hot C7 Asphaltenes (wt.%) wax content (wt.%) 7

N content (ppm) 1620

S content (ppm) 31420 1050+ (wt.%) 4.7 Simdist (°F)

IBP 525

5% 707

15% 776

20% 795

30% 827

35% 841

40% 855

45% 870

50% 883

55% 897

60% 912

65% 927

70% 941

75% 957

80% 975

85% 994

90% 1016

95% 1048

99% 1099

EP 1116

Example 2 - Properties of Atmospheric Resid (AR) Feedstocks

[0085] Samples of atmospheric resids (AR1 to AR5) from commercially available sources were obtained and analyzed. The properties of these AR samples, which were used as feedstock components according to the invention, are shown in Table 2.

Table 2 - Properties of Atmospheric Resid (AR) Feedstocks

Feed AR Sample Property Value

Property AR1 AR2 AR3 AR4 AR5

Sample ID 2147 2188 _ 2361 _ 2591 2614

API Gravity 26.6 36.5 28.9 32.6 32.6

Viscosity Index, VI (D2270) 108 137 106 134 123

Viscosity, 100°C (cSt) 13.23 3.843 8.683 6.425 6.511

Viscosity, 70°C (cSt) 6.957 13.04 13.5

Hot C7 Asphaltenes (wt.%) 0.12 0.0234 0.0379 wax content (wt.%) 24 14 25 21 N content (ppm) 808 70.7 623 340 271 S content (ppm) 5654 805 3938 2266 558 1050+°F (wt.%) 24.2 8.3 15.6 11.9 14.3 Simdist (°F) IBP 439 319 573 431 310 5% 644 477 672 589 543

15% 737 578 722 673 677

20% 766 608 741 699 717

30% 814 666 775 746 774

35% 837 691 792 767 796

40% 860 715 810 785 816

45% 884 737 828 804 836

50% 907 761 849 824 856

55% 931 785 871 845 876

60% 956 809 893 869 896

65% 984 836 918 893 919

70% 1013 865 944 920 942

75% 1045 897 976 948 971

80% 1078 932 1011 982 1003

85% 1116 974 1056 1022 1044

90% 1163 1028 1111 1070 1096

95% 1224 1103 1185 1136 1173

99% 1312 1217 1268 1230 1312

EP 1329 1250 1279 1230 1339

Example 3 - Properties of Blends of Atmospheric Resid (AR) Feedstocks with Vacuum Gas Oil (VGO) Feedstock

[0086] Samples of the atmospheric resids AR1 to AR5 of example 2 were blended with the vacuum gas oil (VGO) feedstock of example 1 on a weight ratio basis and the blends analyzed. The properties of these AR/VGO blend samples, which were used as illustrative feedstocks according to the invention, are shown in Table 3.

Table 3 - Properties of Atmospheric Resid (AR) and Vacuum Gas Oil (VGO) Feedstock Blends

AR/VGO Blend (wt/wt) Sample Property Value

Feed

45% AR1/ 50% AR2/ 53% AR3/ 20% AR4/ 20% AR5/

Property 55% VGO 50% VGO 47% VGO 80% VGO 80% VGO

_ Sample ID _ 2148 2190 2394 3294 4122

API Gravity 20.9 25.9 19.9 19.9 20.6

Viscosity Index, VI (D2270) 73 100 63 72 69 Viscosity, 100°C (cSt) 13.68 6.912 11.99 11.63 11.12 Viscosity, 70°C (cSt) 37.28 15.21 32.4 30.59 29.12

Plot C7 Asphaltenes (wt.%) 0.0386 wax content (wt.%) 18 8

N content (ppm) 1540 1050 1460 1230 1270

S content (ppm) 20490 15630 26160 26620 25880 1050+ (wt.%) 6.4 6 6.8 7.3 Simdist (°F)

IBP 346 551 500 431

5% 702 551 692 693 676

15% 674 760 765 761

20% 804 716 781 786 784

30% 840 778 815 820 818 35% 802 830 835 833

40% 871 823 844 850 848

45% 841 857 865 864

50% 899 860 871 880 879

55% 877 884 895 894

60% 930 894 898 910 910

65% 912 913 927 926

70% 960 929 927 942 942

75% 947 942 960 960

80% 999 969 958 979 980

85% 992 975 1000 1002

90% 1058 1021 993 1027 1030

95% 1132 1064 1015 1066 1075

99% 1172 1046 1166 1246

EP 1327 1216 1051 1204 1313

Example 4 - Evaluation of Group II Base Oil Production from Blends of Atmospheric Resid (AR) Feedstock with Vacuum Gas Oil (VGO) Feedstock

[0087] The blend feedstock samples AR1 to AR5 of the atmospheric resids with vacuum gas oil (VGO) of example 3 were evaluated for Group II base oil production according to the process represented by FIG. 3b. Group II results were also obtained using the VGO feedstock of example 1 (according to the process of FIG. 3a) for comparison.

[0088] Bench scale process conditions used included 0.5 LHSV , reactor pressure of 1850 psig, hydrogen feed gas oil ratio of 4500 scfb, and reactor temperatures in range of 700-770+°F, with the downstream reactor R2 temperature being maintained at 20°F hotter than the upstream R1 reactor. Waxy product target viscosity indexes (Vi's) were set at 109 at 6.1 cSt at 100°C (220R) and 11.8 cSt at 100°C (600R).

[0089] Base oil production results compared with VGO feedstock alone for the ARl/VGO blend are shown in Table 4a, results for blends of AR2 and AR3 with VGO are shown in Table 4b, and results for blends of AR4 and AR5 with VGO are shown in Table 4c, with each set of results determined using the AR/VGO blends of example 3.

[0090] As shown in Table 4a, using the ARl/VGO blend as lube oil process feed showed an improvement in heavy base oil product W600 yield of 57.5 vol% vs. 19.3 vol% when the feed does not include the atmospheric resid AR1 component. This improvement in heavy base oil yield is significant even though the ARl/VGO blend did show some loss in hydrocracking (~15°F) and HDN activity loss (19°F or above). The advantage of high W600 yield suggests a more active and robust HDN catalyst system would also be beneficial, particularly for high nitrogen-containing feedstocks.

Table 4a - Base Oil Production for ARl/VGO (wt/wt) blend

Feed VGO % ARl/55% VGO

Sample I 2018 2148 2148

C2B Simdist (w 0.5% 96 97 95

5% 217 221 209

10% 270 299 259

15% 320 362 310

20% 367 406 358

25% 403 443 392

30% 434 477 421

35% 464 506 452

40% 492 531 480

50% 540 573 529

55% 562 591 550

60% 580 607 573

65% 600 624 592

70% 618 639 611

75% 635 652 630

80% 652 665 649

85% 667 677 666

90% 682 689 682

95% 698 702 698

99% 719 720 719

99.5% 725 728 726

C40 Simdist (w 1% 692 685 690

5% 725 711 717

10% 742 722 729

15% 757 732 739

20% 771 739 748

25% 784 748 757

30% 795 756 765

35% 807 763 774

40% 818 771 782

50% 840 786 799

55% 851 793 808

60% 862 801 817

65% 873 810 827

70% 884 818 837

75% 895 828 848

80% 908 839 859

85% 921 851 873

90% 937 865 888

95% 959 886 911

99% 994 921 948

100% 1004 934 963

C4B Simdist (w 0.5% 740 708 718

5% 828 769 786

10% 865 800 820

15% 888 823 844

20% 906 842 863

25% 920 859 880

30% 932 874 894

35% 942 888 907

40%

952

902 920

[0091] Table 4b presents the results obtained for atmospheric resid samples AR2 and AR3 that are each blended with vacuum gas oil (VGO). As shown, the AR2/VGO blend (90-326-3242-3266) provided significant improvements in both actual waxy W600 yield and total actual waxy yield if the same W220 VI (109 or close) is targeted, 36.6% vs. 18.6 for waxy 600R yield, and 69.4% vs. 53.5% for total waxy yield. While a higher waxy product nitrogen content was obtained, the high product N content could be reduced, as shown in 90-326-3098-3122, at the expense of waxy W600R yield and total waxy base oil yield (6% yield decrease for W600R and 2% yield decrease for total waxy base oil yield).

[0092] From Table 4b, the AR3/VGO blend (88-342-3726-3750) showed significant actual waxy W600R yield improvement compared to VGO feed alone, 31.9% vs. 18.6%. The total actual waxy base oil yield remained the same, while the waxy products from the AR3/VGO blend showed slightly higher nitrogen content.

[0093] Table 4c presents the results obtained for atmospheric resid samples AR4 and AR5 that are each blended with vacuum gas oil (VGO). As shown, two separate runs were performed at different hydrocracking severities for each of the VGO comparative feed and the AR4/VGO and AR5/VGO blends.

Table 4b - Base Oil Production from AR2/VGO and AR3/VGO (wt/wt) blends

Table 4c - Base Oil Production from AR4/VGO and AR5/VGO (wt/wt) Blends

No Loss Product

Yields (wt.%):

C5-180 °F 1.5 2.1 1.7 1.3 2.0 I.3 180-250 °F 1.0 1.9 1.5 0.7 1.8 0.7 250-550 °F 13.7 19.6 16.3 10.6 19.2 II.2 550-700 °F 16.4 18.1 16.6 15.2 17.6 23.7 700+ °F 64.0 54.5 60.8 69.5 56.7 60.5 C5+ 96.6 96.3 97.0 97.2 97.2 97.5

Mass Closure

100 99.4 98.9 99.2 99 99 (wt.%)

Average CAT

727 740

735 725 743

728 (°F)

Waxy product W2 W6 W2 W6 W22 W60 W22 W60 W22 W60 W22 W60

yield: 20 00 20 00 0 0 0 0 0 0 0 0

Product Rate,

18. 8.4 17.4 11.9 18.0 10.9 40 KBPD feed 16.1 9.39 5.97 17.6

6 5 3 2 3 5 basis (KBPD) Viscosity, 100°C

6.00 11.8 6.11 11.7 6.00 6.29

11.8 11.8 (cSt)

8 01 8 98 3 1

Viscosity Index,

116 119 107 109 118 122 105 1 I (D2270)

07 V

Noack Volatility

11.3 1.3 12.7 1.8 11.4 1.1 12.2 1.7 (D5800, wt.%)

[0094] Results from Table 4c provide a basis for comparison of waxy base oil yields at a viscosity index (VI) of 109 for W220 for AR2/VGO, AR4/VGO, and AR5/VGO blends, as shown in Table 4d. At 109 W220 VI, compared to VGO feed alone, the 50% AR2/VGO blend feed showed a waxy base oil yield improvement in W600 yield of 33.7% compared with a W600 yield of 25.8% for VGO feed alone that does not include the atmospheric resid AR2 component. A total waxy base oils yield of 68.7% for the AR2/VGO blend was obtained compared with a total waxy base oils yield of 66.1% when the feed did not contain the AR2 blend component.

[0095] The 20% AR4/VGO blend also showed improvements in both W600 yield of the AR4/VGO blend compared with the VGO feed by itself ( 28.4% vs. 25.8%), in W220 yield of the AR4/VGO blend compared with the VGO feed by itself (42.9% vs. 40.3%), and the total waxy base oil yield of the AR4/VGO blend compared with the VGO feed by itself (71.3% vs. 66.1%).

[0096] Similarly, the 20% AR5/VGO showed improvement in W220 yield of the AR5/VGO blend compared with the VGO feed by itself (44.4% vs.40.3%) and in total waxy base oil W600 yield of the AR5/VGO blend compared with the VGO feed by itself (68.1% vs. 66.1%).

Table 4d - Atmospheric Resid/Vacuum Gas Oil (AR/VGO) Blend Yield Comparison

20% AR4/80% 20% AR5/80%

Feed VGO 50% AR2/50% VGO VGO VGO

Sample ID _ 2358 _ 2190 _ 3924 _ 4122 _

W220 VI 109 109 109 109

W220 yield (vol.%) 40.3 35.0 42.9 44.4

W600 yield (vol.%) 25.8 33.7 28.4 23.8

Total waxy yield (vol.% 66.1 68.7 71.3 68.1

Average CAT (°F) _ 738 _ 713 _ 727 _ 740 _

Example 5 - Evaluation of Atmospheric Resids (AR) to Provide Medium Grade Vacuum Gas Oils (MVGO) for Group III/III+ Base Oil Production

[0097] Samples of atmospheric resid (AR) were evaluated to provide medium grade vacuum gas oils (MVGO) for use in producing group III/III+ base oils. The MVGO samples were derived from the corresponding AR samples as distillation cuts in the following ranges: AR2 cut range of 717-876°F; AR4 cut range of 725-882°F; and, AR5 cut range of 716-882°F. Table 5a presents properties of the AR samples AR2, AR4, and AR5 and the corresponding MVGO derived cuts MVG02, MVG04, and MVG05. Properties for the comparative vacuum gas oil (VGO) are also included.

[0098] The three atmospheric resid (AR) derived MVGO's were evaluated using the process configuration of FIG. 4 for the production of group III base oils at different dewaxing severities with different waxy viscosity indexes (VI) at a kinematic viscosity (KV100) of about 4 cSt at 100°C. Table 5b summarizes the yields for the comparative case of VGO by itself, and MVGO's derived from AR2,

AR4, and AR5 feeds, designated as MVG02, MVG04, and MVG05 feeds, respectively. Table 5a - Properties of Atmospheric Resid (AR) and MVGO Feeds

Table 5b - Comparison of Yields for VGO and MVGO Feeds for Group III Base Oil Production

Example 6 - Evaluation of Medium Vacuum Gas Oils (MVGO) Fractions Derived from Atmospheric Resid Feed AR3

[0099] Samples of atmospheric resid feed sample AR3 were evaluated to provide medium grade vacuum gas oils (MVGO) for use in producing group III/III+ base oils. The MVGO samples were derived from the corresponding AR3 samples as distillation cuts in the 725-895 °F range, designated as MVG03b (broad temperature range cut), and 725-855°F, designated as MVG03n (narrow temperature range cut).

[00100] Table 6 presents the results using the MVG03b and MVG03n feeds to produce group III 4cSt base oils using the process configuration of FIG. 3a. Properties for the comparative vacuum gas oil (VGO) are also included. Both MVGO feeds MVG03b and MVG03n provided increased waxy Group III product yield for 4 cSt base oil production, with the broad cut MVG03b showing a 4.5 lvol.% and the narrow MVGO cut MVG03n showing a 6.6 lvol.% increase compared against the use of the vacuum gas oil (VGO) feed.

Table 6 - MVGO Use for Group III 4 cSt Base Oil Production

Example 7 - Evaluation of Heavy-Heavy Vacuum Gas Oil (HHVGO) Fractions Derived from Atmospheric Resids (AR) to Produce Group II Base Oils [00101] As noted in Example 5, samples of atmospheric resid (AR) were used to provide medium grade vacuum gas oils (MVGO) for use in producing group III/III+ base oils. The remaining fraction, absent the MVGO fraction, was designated as an HHVGO fraction. These HHVGO fractions were evaluated for use as feed components blended with vacuum gas oils (VGO) to produce Group II base oils.

[00102] Table 7a presents the properties of the HHVGO samples HHVG02, HHVG04, and HHVG05 and blend of 9%HHVGO/VGO and 9%HHVGO/VGO. Properties of the comparative VGO feed are also shown.

Table 7a - Properties of HHVGO Fractions and HHVGO/VGO blends

60% 911 1036 923 1044 928 1018

70% 941 1072 952 1086 959 1055

80% 975 1118 987 1141 997 1102

90% 1017 1189 1033 1222 1052 1170

95% 1048 1253 1068 1294 1114 1223

99.5%

1115

1383 1236

1371 1370

1334

[00103] Table 7b presents the results using the HHVGO/VGO blend feeds to produce group II base oils using the process configuration of FIG. 5. Results for the comparative vacuum gas oil (VGO) are also included. The results are further summarized in Table 7c. Both HHVGO feeds, i.e.,

9% HHVG02/VGO and 9% HHVG04/VGO, provided comparable waxy Group II base oil product yields compared with the use of the VGO feed by itself. The combination of using an MVGO cut to produce a Group III base oil and of using the remaining HHVGO fraction to produce a Group II base oil therefore provides technical and economic advantages compared with the use of a vacuum gas oil feed.

Table 7b - Waxy Base Oil Yields from HHVGO/VGO Blend Feeds

Table 7b (continued) - Waxy Base Oil Yields from HHVGO/VGO Blend Feeds

Table 7c - Yield Comparison for HHVGO/VGO Blend Feeds at 109 VI W220

Feed VGO 9% HHVG02/VG0 9% HHVG04/VG0

_ Sampiej _ 2358 _ 3574 _ 3915

W220 Viscosity Index, VI 109 109 109

W220 yield (vol.%) 40.3 40.9 40.0

W600 yield (vol.%) 25.8 25.4 24.3

Total waxy yield (vol. %) 66.1 66.3 64.3

Average CAT (°F) 738_ 725_ 739

[00104] The foregoing description of one or more embodiments of the invention is primarily for illustrative purposes, it being recognized that variations might be used which would still incorporate the essence of the invention. Reference should be made to the following claims in determining the scope of the invention.

[00105] For the purposes of U.S. patent practice, and in other patent offices where permitted, all patents and publications cited in the foregoing description of the invention are incorporated herein by reference to the extent that any information contained therein is consistent with and/or supplements the foregoing disclosure.

Claims

WHAT IS CLAIMED IS:

1. A process for making a base oil, comprising combining an atmospheric resid feedstock and a base oil feedstock to form a base oil feedstream; contacting the base oil feedstream with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product.

2. The process of claim 1, wherein the atmospheric resid feedstock meets one or more of the following conditions:

API gravity in the range of 20-60 or 20-45 or 25-45, or at least 20, or at least 22, or, optionally, greater than the API of the base oil feedstock;

VI in the range of 50-200 or 70-190 or 90-180, or at least 80, or, optionally, greater than the VI of the base oil feedstock; viscosity at 100°C in the range of 3-30 cSt or 3-25 cSt or 3-20 cSt, or at least 3 cSt, or at least 4 cSt; viscosity at 70°C in the range of 5-25 cSt or 5-20 cSt or 5-15 cSt, or at least 5cSt, or at least 6 cSt; hot C₇ asphaltene content in the range of 0.01-0.3 wt.% or 0.01-0.2 wt.% or 0.02-0.15 wt.%, or less than 0.3 wt. %, or less than 0.2 wt.%; wax content in the range of 5-40 wt.% or 5-30 wt.% or 10-25 wt.%, or at least 5 wt.% or at least 10 wt.%, or at least 15 wt.%, or, optionally, greater than the wax content of the base oil feedstock; nitrogen content of less than 2500 ppm or less than 2000 ppm or less than 1500 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm or less than 100 ppm; sulfur content of less than 8000 ppm or less than 6000 ppm or less than 4000 ppm or less than 2000 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm, or in the range of 100-8000 ppm or 100-6000 ppm or 100-4000 ppm or 100-2000 ppm or 100-1000 ppm or 100-500 ppm or 100-200 ppm; and/or

1050+°F content in the range of 5-50 wt.% or 5-40 wt.% or 8-40 wt.%, or, optionally, greater than the 1050+°F content of the base oil feedstock.

3. The process of any one of claims 1-2, wherein the base oil feedstock meets one or more of the following conditions:

API gravity in the range of 15-40 or 15-30 or 15-25, or at least 15, or at least 17, optionally, less than the atmospheric resid feedstock;

VI in the range of 30-90 or 40-90 or 50-90 or 50-80, optionally, less than the VI of the atmospheric resid feedstock; viscosity at 100°C in the range of 3-30 cSt or 3-25 cSt or 3-20 cSt, or at least 3 cSt, or at least 4 cSt; viscosity at 70°C in the range of 5-25 cSt or 5-20 cSt or 5-15 cSt, or at least 5cSt, or at least 6 cSt; hot C₇ asphaltene content in the range of 0.01-0.3 wt.% or 0.01-0.2 wt.% or 0.02-0.15 wt.%, or less than 0.3 wt. %, or less than 0.2 wt.%; wax content in the range of 5-40 wt.% or 5-30 wt.% or 10-25 wt.%, or at least 5 wt.% or at least 10 wt.%, or at least 15 wt.%, or, optionally, greater than the wax content of the base oil feedstock; nitrogen content of less than 2500 ppm or less than 2000 ppm or less than 1500 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm or less than 100 ppm; sulfur content of less than 8000 ppm or less than 6000 ppm or less than 4000 ppm or less than 2000 ppm or less than 1000 ppm or less than 500 ppm or less than 200 ppm, or in the range of 100-8000 ppm or 100-6000 ppm or 100-4000 ppm or 100-2000 ppm or 100-1000 ppm or 100-500 ppm or 100-200 ppm; and/or

1050+°F content in the range of 5-50 wt.% or 5-40 wt.% or 8-40 wt.%, or, optionally, greater than the 1050+°F content of the base oil feedstock.

4. The process of any one of claims 1-3, wherein the base oil feedstream comprises 10-60 wt.% atmospheric resid feedstock and 40-90 wt.% base oil feedstock, or 10-40 wt.% atmospheric resid feedstock and 60-90 wt.% base oil feedstock, or 10-30 wt.% atmospheric resid feedstock and 70-90 wt.% base oil feedstock, or 30-60 wt.% atmospheric resid feedstock and 40-70 wt.% base oil feedstock, or 40-60 wt.% atmospheric resid feedstock and 40-60 wt.% base oil feedstock.

5. The process of any one of claims 1-4, wherein the base oil feedstream does not contain an added whole crude oil feedstock, or wherein the base oil feedstream does not contain a vacuum residue feedstock, or wherein the base oil feedstream does not contain a deasphalted oil, or wherein the base oil feedstream contains only atmospheric resid feedstock and base oil feedstock.

6. The process of any one of claims 1-5, wherein the process does not include recycle of a liquid feedstock as part of the base oil feedstream or as either or both of the atmospheric resid feedstock and the base oil feedstock.

7. The process of any one of claims 1-6, wherein the base oil feedstock comprises vacuum gas oil or is vacuum gas oil, or consists essentially of vacuum gas oil, or consists of vacuum gas oil.

8. The process of claim 7, wherein the vacuum gas oil is a heavy vacuum gas oil obtained from vacuum gas oil that is cut into a light fraction and a heavy fraction, with the heavy fraction having a cut point temperature range of about 950-1050 °F.

9. The process of any one of claims 1-8, wherein the dewaxed product and/or the hydrofinished dewaxed product is obtained as a light base oil product and a heavy base oil product.

10. The process of claim 9, wherein the light base oil product has a nominal viscosity in the range of 4-8 cSt or 5-7 cSt at 100°C and/or the heavy base oil product has a nominal viscosity in the range of 10-14 cSt or 11-13 cStat 100°C.

11. The process of any one of claims 9-10, wherein the yield of the heavy base oil product relative to the light base oil product is increased by at least about 2 Lvol.% or at least about 5 Lvol% compared with the same process that does not include the atmospheric resid feedstock in the base oil feedstream.

12. The process of any one of claims 9-11, wherein the total waxy base oil yield is increased by at least about 2 Lvol.% or at least about 5 Lvol% compared with the same process that does not include the atmospheric resid feedstock in the base oil feedstream.

13. The process any one of claims 1-10, wherein the dewaxed product is further separated into at least a lighter product having a nominal viscosity of 6 cSt at 100°C, or at least a heavier product having a nominal viscosity of 12 cSt at 100°C, or a combination thereof.

14. A method for modifying a base oil process, wherein the base oil process comprises subjecting a base oil feedstream to hydrocracking and dewaxing steps to form a dewaxed product comprising a light product and a heavy product; the method comprising, combining an atmospheric resid feedstock with a base oil feedstock to form the base oil feedstream; and subjecting the base oil feedstream comprising the atmospheric resid feedstock to the hydrocracking and dewaxing steps of the base oil process; wherein the modified base oil process comprises: combining an atmospheric resid feedstock and a base oil feedstock to form a base oil feedstream; contacting the base oil feedstream with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product; separating the hydrocracked product into at least a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product.

15. A process for making a base oil, comprising contacting a base oil feedstock having a viscosity index of about 100 or greater with a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked product, wherein the base oil feedstock comprises vacuum gas oil having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less; separating the hydrocracked product into a gaseous fraction and a liquid fraction; contacting the liquid fraction with a dewaxing catalyst under hydroisomerization conditions, to produce a dewaxed product; and optionally, contacting the dewaxed product with a hydrofinishing catalyst under hydrofinishing conditions to produce a hydrofinished dewaxed product; wherein, the dewaxed product and/or the hydrofinished dewaxed product has a viscosity index of 120 or greater after dewaxing.

16. The process of claim 15, wherein the dewaxed product and/or the hydrofinished dewaxed product has a viscosity index of 130 or greater after dewaxing, or 135 or greater after dewaxing, or 140 or greater after dewaxing.

17. The process of claim 15, wherein the dewaxed product and/or the hydrofinished dewaxed product comprises a Group III or Group 111+ base oil product.

18. The process of claim 15, wherein the hydrocracked product has a viscosity index of at least about 135, or 140, or 145, or 150.

19. The process of any one of claims 15-18, wherein the waxy product yield at a viscosity of 4cSt 100°C of the vacuum gas oil having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less is at least about 3 lvol.% greater than the same process that does not include the vacuum gas oil having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less as the base oil feedstock.

20. A process for making a base oil from a base oil feedstock, or a fraction thereof, the process comprising providing an atmospheric resid fraction from a base oil feedstock, or a fraction thereof; separating the base oil feedstock, or a fraction thereof, and/or the base oil atmospheric resid fraction into a vacuum gas oil cut-point fraction having a front end cut point of about 700°F or greater and a back end cut point of about 900°F or less to form a medium vacuum gas oil MVGO fraction and a heavy vacuum gas oil FIFIVGO fraction; using the FIFIVGO fraction as the atmospheric resid feedstock in the process of claim 1; and/or using the MVGO fraction as the base oil feedstock in the process of claim 14.

21. The process of claim 20, wherein the base oil feedstock comprises tight oil, or a fraction thereof.

22. The process of claim 21, wherein the vacuum gas oil cut-point fraction is derived from the atmospheric resid fraction of the tight oil.