CN110662822A

CN110662822A - Production of diesel and base oils from crude oil

Info

Publication number: CN110662822A
Application number: CN201880033334.5A
Authority: CN
Inventors: 斯蒂芬·H·布朗; 迈克尔·B·卡洛尔
Original assignee: ExxonMobil Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2017-06-07
Filing date: 2018-05-24
Publication date: 2020-01-07
Also published as: JP7137585B2; US20180355264A1; WO2018226416A1; JP2020523436A; EP3635076A1

Abstract

The present invention provides a process for producing group III base oils from whole waxy crude oil, as well as naphtha and diesel products. The process of the present invention omits the typical vacuum distillation stage and separation to form the typical cut fraction of a vacuum column. By selecting a waxy crude oil suitable for processing without separation, the crude oil can be hydroprocessed, dearomatized, dewaxed, and hydrofinished to produce a group III base oil. Additionally, the dewaxing catalyst will isomerize naphtha range molecules to increase octane numbers to levels suitable for incorporation into gasoline and diesel range molecules, thereby lowering the diesel cloud point.

Description

Production of diesel and base oils from crude oil

Technical Field

Systems and methods for producing diesel and lubricant base oils from waxy whole crude oil are provided.

Background

Crude oil can be distilled and fractionated into many products such as gasoline, kerosene, jet fuel, asphaltenes, and the like. A portion of the crude oil forms the base stock of lubricating base oils used, inter alia, to lubricate internal combustion engines. Lubricating oil users are demanding ever-increasing base oil quality and refiners find that the equipment available to them is becoming increasingly incapable of producing base oils that meet these higher quality specifications. New processes are needed to provide refiners with tools to make high quality modern base oils, especially using existing equipment at lower cost and with safer operation.

Finished lubricants used for such things as automobiles, diesel engines, and industrial applications are typically composed of a lubricant base oil and additives. Generally, several lubricant base oils are used to produce a wide variety of finished lubricants by varying the blend of individual lubricant base oils and individual additives. Typically, lubricant base oils are simply hydrocarbons prepared from petroleum or other sources. Lube base oils are normally made by making narrow cuts of vacuum gas oil from a crude vacuum tower. The cut point is set to control the final viscosity and flash point of the lubricant base oil.

Group I base oils, i.e., those having greater than 300ppm sulfur and 10 wt% aromatics, are typically produced by: the vacuum gas oil (or waxy distillate) is first extracted with a polar solvent such as N-methyl-pyrrolidone, furfural or phenol. The resulting waxy raffinate produced from the solvent extraction process is then dewaxed catalytically, or by solvent dewaxing, using a dewaxing catalyst such as ZSM-5. The resulting base oil may be hydrofinished to improve color and other lubricant properties.

Group II base oils, i.e., those having less than 300ppm sulfur and 10 wt% aromatics and a viscosity index in the range of 8 to 120, are typically produced by hydrocracking followed by selective catalytic dewaxing and hydrofinishing. Hydrocracking increases the viscosity index of entrained oil in the feedstock through ring cracking and aromatics saturation. The aromatics saturation is limited by the high temperatures (300-. In the second stage of the process, the hydrocracked oil is dewaxed by either solvent dewaxing or catalytic dewaxing, with catalytic dewaxing generally being the preferred method. The dewaxed oil is then preferably hydrofinished at mild temperatures (150-.

Group III base oils have the same sulfur and aromatics specifications as group II base oils, but a viscosity index in excess of 120. These materials are made using the same type of catalytic technology used to produce group II base oils, but the hydrocrackers are operated at higher severity or use feedstocks with higher wax content.

A typical lube oil hydroprocessing unit consists of two main processing stages. In the lead stage, the feedstock, typically a vacuum gas oil, a deasphalted oil, a processed gas oil, or any combination of these materials, is hydrocracked. In the second stage, the hydrocracked oil is dearomatised, preferably with an aromatic saturation catalyst, and dewaxed, preferably using a highly shape selective catalyst capable of converting wax by isomerization. The dewaxed, dearomatized oil may then be hydrofinished to remove PNA impurities. Because in the final hydrofinishing step, due to its low operating temperature, significant conversion of mono-and bicyclic aromatics cannot be achieved, the operation of the final hydrofinishing step is optimized to convert PNA impurities.

It is desirable to continue to improve the process of base oil production, particularly group III base oils having more stringent specifications, by minimizing the required processing stages and the required separation.

Disclosure of Invention

The claimed invention provides a process for producing group III base oils, as well as naphtha and diesel products, from whole waxy crude without the need for a typical vacuum distillation stage and separation to form a typical cut off fraction (cut off) for a vacuum tower. By selecting a waxy crude oil suitable for processing without separation, the crude oil may be hydroprocessed, dearomatized, dewaxed, and hydrofinished to produce a group III base oil. Additionally, the dewaxing catalyst will isomerize naphtha range molecules to increase octane numbers to levels suitable for incorporation into gasoline and diesel range molecules, thereby lowering the diesel cloud point.

In one embodiment, a method for producing a lubricant base oil from whole petroleum crude oil is provided. An all petroleum crude oil feedstock containing less than about 2 wt% heptane asphaltenes, less than about 2 wt% Conradson Carbon Residue (CCR) and less than about 50ppm metals is hydrotreated in at least one hydrotreating catalyst bed under effective hydrotreating conditions to produce a hydrotreated effluent containing less sulfur, nitrogen and aromatics than the all petroleum crude oil. The hydrotreated effluent is then dewaxed in the presence of a dewaxing catalyst to produce a naphtha product having an octane number greater than 60, a diesel product having a cloud point below 0 ℃, and a lubricant base oil product which is fractionated into at least a low viscosity lubricant base oil product having a viscosity of from 2 to 8cSt at 100 ℃ and a high viscosity lubricant base oil product having a viscosity of from 6 to 30cSt at 100 ℃.

In another embodiment, a naphtha product, a diesel product, and a lubricant base oil product are produced from whole petroleum crude oil. Whole petroleum crude oil feedstock containing less than about 2 wt% heptane asphaltenes, less than about 2 wt% Conradson Carbon Residue (CCR) and less than about 50ppm metals is provided without separation or pretreatment to a hydroprocessing unit where it is hydroprocessed over at least one hydroprocessing catalyst bed under effective hydroprocessing conditions to produce a crude oil having less than 15ppm sulfur, less than 5ppm nitrogen, less than 2 wt% C₃-a hydrotreating effluent of paraffins and less than 25 wt% aromatics. Dewaxing the hydrotreated effluent in the presence of a dewaxing catalyst to produce a dewaxed effluent, separating the dewaxed effluent into at least a naphtha product having an octane number greater than 60 and a diesel product having a cloud point below 0 ℃And a base stock product. Hydrofinishing and/or aromatics saturation of the base stock product to remove polynuclear aromatics and produce a hydrofinished base stock, which is then fractionated into at least a low viscosity lubricant base oil product having a viscosity of from 2 to 8cSt at 100 ℃ and a high viscosity lubricant base oil product having a viscosity of from 6 to 30cSt at 100 ℃.

Drawings

FIG. 1 schematically shows one example of a configuration suitable for processing a whole waxy crude oil feed to form a lubricant base oil.

Detailed Description

All numbers expressing values of quantities within the detailed description and claims are to be understood as being modified by the term "about" or "approximately" in view of experimental error and variations contemplated by those skilled in the art.

SUMMARY

In various embodiments, a method of producing a lubricant base oil from crude oil is provided. In a typical lube base oil production process, crude oil is subjected to atmospheric distillation to obtain distillate and atmospheric residue. Then the atmospheric residue is sent to vacuum distillation, at least volatile fraction oil, light neutral fraction oil, heavy neutral fraction oil and vacuum residue oil are obtained. The vacuum residuum is then deasphalted to remove asphaltenes, and the deasphalted oil is then solvent extracted along with light neutral and heavy neutral fractions to remove aromatics. The raffinate from the solvent extraction may then be hydroprocessed and dewaxed to produce a base oil. However, the present inventors have discovered a process that eliminates several steps of the typical process, specifically atmospheric distillation, vacuum distillation, deasphalting and solvent extraction, while still producing high quality lubricant base oils.

FIG. 1 shows an example reactor system 100 for use in the process of the present invention. In one embodiment of the inventive process, a feedstock 102 meeting certain specifications (described in detail below) is hydrotreated in a first stage in a hydroprocessing unit 110 to remove sulfur, nitrogen, and saturated aromatics. Hydrotreated streamsThe effluent 112 is then treated in a second stage 120 over a stacked bed of noble metal catalyst. The top bed of noble metal hydrogenation catalyst also saturates the aromatics in the hydrotreated effluent 112. The bottom bed contains a catalytic dewaxing catalyst which converts C₄-C₈Normal paraffins (naphtha range molecules) isomerize to high octane isoparaffins to give a naphtha product with an octane number greater than 70, which can be directly incorporated into gasoline. Catalytic dewaxing catalyst also comprises₉Normal paraffins boiling to 650 ° f- (343 ℃) isomerize to low pour point isoparaffins to lower the diesel cloud point and normal paraffins in the 650 ° f + (343 ℃) +) range isomerize to low pour point group III lubricant base oils. The dewaxed effluent 122 is separated by distillation in column 130 into a naphtha fraction 132, a diesel fraction 134 and a base stock fraction 136, and the base stock fraction 136 is hydrofinished in a hydrofinishing unit 140 to remove trace amounts of polynuclear aromatics. The hydrofinished base stock 142 is then stripped to remove light hydrocarbons and separated in column 150 into two fractions-a light neutral base stock 152 having a low viscosity of 3-5cSt (at 100 ℃) and a heavy neutral base stock 154 having a high viscosity of 8-15cSt (at 100 ℃). Both group III base stock fractions have a viscosity index greater than 120, a pour point of-15 ℃, and a cloud-pour point spread of less than 30 ℃.

Raw materials

Suitable feedstocks for the present invention include whole petroleum crude oil low in metals and heptane asphaltenes. These whole petroleum crudes often contain significant amounts of waxy hydrocarbons. Ideally, the feedstock would be suitable for processing without separation.

One way of defining the feedstock is based on the boiling range of the feedstock. One option for defining the boiling range is to use the initial boiling point of the feed and/or the final boiling point of the feed. Another option that may provide a more representative description of the feed in some cases is to characterize the feed based on the amount that the feed boils at one or more temperatures. For example, the "T5" boiling point of a feed is defined as the temperature at which 5 wt% of the feed will boil off. Similarly, the "T50" boiling point is the temperature at which 50 wt% of the feed will boil. The percentage of feed that will boil at a given temperature can be determined by the method specified in ASTM D2887. Fully waxy crude suitable for the claimed process includes, for example, a feed having an initial boiling point of at least 70 ° f (21 ℃), or at least 100 ° f (37 ℃), or at least 125 ° f (51 ℃).

In some aspects, the heptane asphaltene content of the whole crude oil feedstock can be less than 2.0 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.25 wt%, based on the total weight of the feedstock. The 1050F. + (565℃. +) fraction of the feed had a heptane asphaltene content of less than 5.0 wt%. The metal content of the feedstock may be less than 50ppm, or less than 20ppm, or less than 15ppm, or less than 10ppm, or less than 5ppm, and the carbonaceous residue content is less than 2.0 wt%, or less than 1.5 wt%, or less than 1.0 wt%, or less than 0.5 wt%, as measured by the micro carbon residue test specified in ASTM D4530.

Hydrotreating process

The feedstock 102 is hydrotreated in a first stage of the reactor system by a hydroprocessing unit 110. Hydrotreating is typically used to reduce the sulfur, nitrogen, and aromatics content of the feed. Catalysts for the hydroprocessing of crude oils may include conventional hydroprocessing catalysts, such as catalysts comprising at least one non-noble group VIII metal (columns 8-10 of the IUPAC periodic table), preferably Fe, Co and/or Ni, such as Co and/or Ni, and at least one group VI metal (column 6 of the IUPAC periodic table), preferably Mo and/or W. Such hydroprocessing catalysts optionally comprise a transition metal sulfide impregnated/dispersed on a refractory support or carrier, such as alumina and/or silica. The support or carrier itself generally has no significant/measurable catalytic activity. Catalysts that are substantially free of a support or carrier, commonly referred to as bulk catalysts, generally have a higher volumetric activity than their supported counterparts.

The catalyst may be in bulk form or in supported form. In addition to alumina and/or silica, other suitable support/support materials may include, but are not limited to, zeolites, titania, silica-titania, and titania-alumina. Suitable aluminas are porous aluminas, for example having an average pore diameter of from 50 toOr 75 toThe specific surface area is 100 to 300m²Per g, or from 150 to 250m²(ii)/g; and a pore volume of 0.25 to 1.0cm³Per g, or 0.35 to 0.8cm³Gamma or eta-alumina in a gram. More generally, any convenient size, shape and/or pore size distribution of the catalyst suitable for hydrotreating distillate (including lube base stock) boiling range feeds in a conventional manner may be used. It is also within the scope of the present disclosure that more than one type of hydroprocessing catalyst may be used in one or more reaction vessels.

The at least one group VIII non-noble metal in oxide form may generally be present in an amount ranging from 2 wt% to 40 wt%, preferably from 4 wt% to about 15 wt%. The at least one group VI metal in oxide form may generally be present in an amount ranging from 2 wt% to 70 wt%, preferably from 6 wt% to 40 wt% or from 10 wt% to 30 wt% for the supported catalyst. These weight percentages are based on the total weight of the catalyst. Suitable metal catalysts include cobalt/molybdenum (1-10% Co as an oxide, 10-40% Mo as an oxide), nickel/molybdenum (1-10% Ni as an oxide, 10-40% Co as an oxide), or nickel/tungsten (1-10% Ni as an oxide, 10-40% W as an oxide) on alumina, silica-alumina, or titania.

The hydrotreatment is carried out in the presence of hydrogen. Thus, a hydrogen stream is fed or injected into the vessel or reaction zone or hydroprocessing zone in which the hydroprocessing catalyst is located. The hydrogen contained in the hydrogen "treat gas" is supplied to the reaction zone. The treat gas, as referred to in this disclosure, may be pure hydrogen or a hydrogen-containing gas, which is a gas stream containing sufficient hydrogen for the intended reaction, optionally containing one or more other gases (e.g., nitrogen and light hydrocarbons such as methane), and which does not adversely interfere with or affect the reaction or product. Impurities, e.g. H₂S and NH₃Is not wanted, let aloneOften removed from the process gas before it is conducted to the reactor. The process gas stream introduced into the reaction stage will preferably contain at least 50 vol% and more preferably at least 75 vol% hydrogen.

The hydrogen supply rate may be 100SCF/B (standard cubic feet of hydrogen per barrel feed) (17Nm³/m³) To 1500SCF/B (253 Nm)³/m³). Preferably, the hydrogen is supplied in the range of 200SCF/B (34 Nm)³/m³) To 1200SCF/B (202 Nm)³/m³). Hydrogen may be supplied to the hydroprocessing reactor and/or reaction zone co-currently with the input feed or separately to the hydroprocessing zone via a separate gas conduit.

Hydrotreating conditions may include a temperature of 200 ℃ to 450 ℃, or 315 ℃ to 425 ℃, preferably 340 ℃ to 420 ℃; a pressure of 250psig (1.8MPag) to 5000psig (34.6MPag) or 300psig (2.1MPag) to 3000psig (20.8MPag), preferably 1500psig (10.3MPag) to 2500psig (13.8MPag), more preferably 1750psig (12.1MPag) to 2250psig (13.1 MPag); liquid Hourly Space Velocity (LHSV) of 0.1hr^-1To 10hr^-1Preferably 0.1hr^-1To 2hr^-1More preferably 0.3hr^-1To 0.7hr^-1(ii) a And a hydrogen processing rate of 200SCF/B (35.6 m)³/m³) To 10,000SCF/B (1781 m)³/m³) Or 500(89 m)³/m³) To 10,000SCF/B (1781 m)³/m³)。

Hydrotreating may be carried out in one or more catalyst beds. In one embodiment, the hydroprocessing unit 110 contains more than one hydroprocessing catalyst bed, in some embodiments two catalyst beds, and in some embodiments three catalyst beds. Hydrotreated effluent 112 contains less sulfur, nitrogen, and aromatics than feedstock 102. In some embodiments, the hydrotreated effluent 112 will contain less than 15ppm sulfur, less than 5ppm nitrogen, less than 2 wt% C₃Paraffins and less than 25 wt% aromatics.

In addition or alternatively to contacting the petrolatum with the hydrotreating catalyst, the petrolatum may be contacted with one or more beds of hydrocracking catalyst. As noted above, hydrocracking conditions can be selected such that the total conversion from all hydrotreating and/or hydrocracking stages is 15 wt% or less, or 10 wt% or less, or 8 wt% or less.

Hydrocracking catalysts typically contain a metal sulfide on an acidic support such as amorphous silica alumina, cracking zeolites such as USY, or acidified alumina. These acidic supports are often mixed or combined with other metal oxides such as alumina, titania or silica. Non-limiting examples of metals for hydrocracking catalysts include nickel, nickel-cobalt-molybdenum, nickel-tungsten, nickel-molybdenum, and/or nickel-molybdenum-tungsten. Additionally or alternatively, hydrocracking catalysts with noble metals may also be used. Non-limiting examples of noble metal catalysts include those based on platinum and/or palladium. Support materials that may be used for both the noble and non-noble metal catalysts may include refractory oxide materials such as alumina, silica, alumina-silica, kieselguhr, diatomaceous earth (diatomaceous earth), magnesia, zirconia, or combinations thereof, with alumina, silica, alumina-silica being the most common (and in one embodiment, preferred).

In various aspects, the conditions selected for hydrocracking can depend on the desired conversion level, the level of contaminants in the input feed to the hydrocracking stage, and potentially other factors. The hydrocracking process can be at a temperature of 550 DEG F (288 ℃) to 840 DEG F (449 ℃), a hydrogen partial pressure of 250psig to 5000psig (1.8MPag to 34.6MPag), 0.05h^-1To 10h^-1And a liquid hourly space velocity of 35.6m³/m³To 1781m³/m³(200SCF/B to 10,000SCF/B) at a hydrogen treat gas rate. In other embodiments, conditions may include a temperature in the range of 600 ° F (343 ℃) to 815 ° F (435 ℃), a hydrogen partial pressure in the range of 500psig to 3000psig (3.5MPag to 20.9MPag), and a hydrogen treat gas rate of 213m³/m³To 1068m³/m³(1200SCF/B to 6000 SCF/B). The LHSV relative to the hydrocracking catalyst alone may be 0.25h^-1To 50h^-1E.g. 0.5h^-1To 20h^-1And preferably 1.0h^-1To 4.0h^-1。

In some aspects, a high pressure stripper (or other type of separator) may then be used between the hydrotreating stage 110 and the catalytic dewaxing stage 120 of the reaction system to remove sulfur and nitrogen contaminants from the gas phase. The separator allows for the contaminant gases (e.g., H) formed during hydrotreating to be removed before the hydrotreated effluent 112 enters the next stage of the reaction system₂S and NH₃) Removed from the reaction system. One option for the separator is to simply perform a gas-liquid separation to remove the contaminants. Another option is to use a separator, such as a flash separator, which can perform the separation at a higher temperature.

Catalytic dewaxing process

The hydrotreated effluent 112 is then processed over one or more catalyst beds containing dewaxing catalyst in a catalytic dewaxing unit 120. Typically, the dewaxing catalyst is located in any hydrotreating catalyst stage and/or in a bed downstream of any hydrotreating catalyst present in the stage. This may allow dewaxing to occur on molecules that have been hydrotreated to remove a significant portion of the organosulfur and nitrogen-containing species.

Suitable dewaxing catalysts may include molecular sieves, such as crystalline aluminosilicates (zeolites). In one embodiment, the molecular sieve may comprise, consist essentially of, or be a molecular sieve having a structure with 10-membered rings or less, such as ZSM-22, ZSM-23, ZSM-35 (or ferrierite), ZSM-48, or combinations thereof, such as ZSM-23 and/or ZSM-48, or ZSM-48 and/or zeolite beta. Optionally but preferably, molecular sieves that selectively dewax by isomerization rather than cracking, such as ZSM-48, ZSM-23, or combinations thereof, may be used. Additionally or alternatively, the molecular sieve may comprise, consist essentially of, or be a 10-membered ring 1-D molecular sieve. Examples include EU-1, ZSM-35 (or ferrierite), ZSM-11, ZSM-57, NU-87, SAPO-11, ZSM-48, ZSM-23 and ZSM-22. Preferred materials are EU-2, EU-11, ZBM-30, ZSM-48 or ZSM-23. ZSM-48 is most preferred. Note that zeolites having the structure of ZSM-23 and silica to alumina ratios of 20:1 to 40:1 may sometimes be referred to as SSZ-32. Optionally but preferably, the dewaxing catalyst can comprise a binder for the molecular sieve, such as alumina, titania, silica-alumina, zirconia or a combination thereof, such as alumina and/or titania or silica and/or zirconia and/or titania.

Preferably, the dewaxing catalyst used in the process of the present disclosure is a low silica to alumina ratio catalyst. For example, for ZSM-48, the zeolite may have a silica to alumina ratio of less than 200:1, such as less than 110:1, or less than 100:1, or less than 90:1, or less than 75: 1. In various embodiments, the silica to alumina ratio can be 50:1 to 200:1, such as 60:1 to 160:1, or 70:1 to 100: 1.

In various embodiments, the catalysts of the present disclosure further comprise a metal hydrogenation component. The metal hydrogenation component is typically a group VI and/or group VIII metal. Preferably, the metal hydrogenation component is a group VIII noble metal. Preferably, the metal hydrogenation component is Pt, Pd or mixtures thereof. In an alternative preferred embodiment, the metal hydrogenation component may be a combination of a non-noble group VIII metal and a group VI metal. Suitable compositions may comprise Ni, Co or Fe with Mo or W, preferably Ni with Mo or W.

The metal hydrogenation component may be added to the catalyst in any convenient manner. One technique for adding the metal hydrogenation component is by incipient wetness impregnation. For example, after the zeolite and binder are combined, the combined zeolite and binder can be extruded into catalyst particles. These catalyst particles may then be treated with a solution containing a suitable metal precursor. Alternatively, the metal may be added to the catalyst by ion exchange, wherein the metal precursor is added to the mixture of zeolite (or zeolite and binder) prior to extrusion.

The amount of metal in the catalyst may be at least 0.1 wt% based on the catalyst, or at least 0.15 wt%, or at least 0.2 wt%, or at least 0.25 wt%, or at least 0.3 wt%, or at least 0.5 wt% based on the catalyst. The amount of metal in the catalyst can be 20 wt% or less, or 10 wt% or less, or 5 wt% or less, or 2.5 wt% or less, or 1 wt% or less, based on the catalyst. For embodiments in which the metal is Pt, Pd, other group VIII noble metals, or combinations thereof, the amount of metal can be 0.1 to 5 wt%, preferably 0.1 to 2 wt%, or 0.25 to 1.8 wt%, or 0.4 to 1.5 wt%. For embodiments in which the metal is a group VIII non-noble metal and a group VI metal, the total amount of metal may be 0.5 wt% to 20 wt%, or 1 wt% to 15 wt%, or 2.5 wt% to 10 wt%.

Dewaxing catalysts useful in the methods of the present disclosure can also comprise a binder. In some embodiments, the dewaxing catalysts used in the methods of the present disclosure are formulated using a low surface area binder, where low surface area binder means a specific surface area of 100m²(ii) g or less, or 80m²(ii) g or less, or 70m²A binder per gram or less. The amount of zeolite in the catalyst formulated with the binder may be from 30 wt% to 90 wt% zeolite relative to the combined weight of the binder and zeolite. Preferably, the amount of zeolite is at least 50 wt%, such as at least 60 wt% or 65 wt% to 80 wt% of the combined weight of zeolite and binder.

The zeolite may be combined with the binder in any convenient manner. For example, the bound catalyst may be produced by: starting with powders of both zeolite and binder, the powders are combined and milled with added water to form a mixture, which is then extruded to produce a bound catalyst of the desired size. Extrusion aids may also be used to modify the extrusion flow properties of the zeolite and binder mixture. The amount of framework alumina in the catalyst may range from 0.1 to 3.33 wt%, or 0.1 to 2.7 wt%, or 0.2 to 2 wt%, or 0.3 to 1 wt%.

Process conditions for the catalytic dewaxing zone can include a temperature of from 200 to 450 deg.C, preferably from 270 to 400 deg.C, a hydrogen partial pressure of from 1.8MPag to 34.6MPag (250psig to 5000psig), preferably from 4.8MPag to 20.8MPag, and a hydrogen recycle rate of 35.6m³/m³(200SCF/B) to 1781m³/m³(10,000SCF/B), preferably 178m³/m³(1000SCF/B) to 890.6m³/m³(5000 SCF/B). In yet other embodiments, conditions may include a temperature of from 600 ° F (343 ℃) to 815 ° F (435℃)) In the range of 500psig to 3000psig (3.5MPag-20.9MPag) hydrogen partial pressure and 213m hydrogen treat gas rate³/m³To 1068m³/m³(1200SCF/B to 6000 SCF/B). The Liquid Hourly Space Velocity (LHSV) can be 0.2h^-1To 10h^-1E.g. 0.5h^-1To 5h^-1And/or 1h^-1To 4h^-1。

The dewaxed effluent 122 is separated by distillation in column 130 into a naphtha product 132 boiling in the range of less than about 350 ° f (176 ℃), a diesel product 134 boiling in the range of about 350 ° f (176 ℃) to about 700 ° f (371 ℃), and a group III lube base stock product 136 boiling above about 700 ° f (371 ℃). The octane number of the naphtha product 132 is greater than 60, preferably greater than 65, more preferably greater than 70, and desirably greater than 75, so that it can be directly blended into gasoline. The diesel product 134 has a T90 between 650 DEG F (343 ℃) and 700 DEG F (371 ℃), a cloud point below 0 ℃, preferably below-10 ℃, more preferably below-15 ℃, and qualifies as an ultra low sulfur diesel product. The base feed product 136 has a class III quality, a viscosity index greater than 120, less than 300ppm sulfur, and 10 wt% aromatics.

Hydrofinishing and/or aromatics saturation process

In some aspects, the base feedstock product 136 is processed through a hydrofinishing and/or aromatics saturation stage 140. Hydrofinishing and/or aromatics saturation catalysts may include catalysts comprising a group VI metal, a group VIII metal, and mixtures thereof. In one embodiment, the preferred metal comprises at least one metal sulfide having a strong hydrogenation function. In another embodiment, the hydrofinishing catalyst may include a group VIII noble metal, such as Pt, Pd, or combinations thereof. Mixtures of metals may also be present as bulk metal catalysts, wherein the amount of metal is 30 wt% or more based on the catalyst. Suitable metal oxide supports include low acid oxides such as silica, alumina, silica-alumina or titania, preferably alumina. A preferred hydrofinishing catalyst for aromatics saturation will comprise at least one metal having a relatively strong hydrogenation function on a porous support. Typical support materials include amorphous or crystalline oxide materials such as alumina, silica, and silica-alumina. The support material may also be modified, for example by halogenation, or in particular fluorination. For non-noble metals, the metal content of the catalyst is often up to 20 wt.%. In one embodiment, a preferred hydrofinishing catalyst may comprise a crystalline material belonging to the M41S class or family of catalysts. The M41S family of catalysts are mesoporous materials with high silica content. Examples include MCM-41, MCM-48, and MCM-50. A preferred member of this class is MCM-41. If a separate catalyst is used for aromatics saturation hydrofinishing, the aromatics saturation catalyst may be selected based on activity and/or selectivity to aromatics saturation, while the hydrofinishing catalyst may be selected based on activity to improve product specifications, such as product color and reduce polynuclear aromatics.

Hydrofinishing conditions can include a temperature of 125 ℃ to 425 ℃, preferably 180 ℃ to 280 ℃, a hydrogen partial pressure of 500psig (3.4MPa) to 3000psig (20.7MPa), preferably 1500psig (10.3MPa) to 2500psig (17.2MPa), and a liquid hourly space velocity of 0.1hr^-1To 5hr^-1LHSV, preferably 0.5hr^-1To 1.5hr^-1. In addition, 35.6m may be used³/m³To 1781m³/m³(200SCF/B to 10,000 SCF/B).

The hydrofinished base stock 142 is then stripped to remove light hydrocarbons and separated in column 150 into two fractions-a light neutral base stock 152 having a low viscosity of from 2 to 8cSt (at 100 ℃), preferably from 3 to 5cSt (at 100 ℃), and a heavy neutral base stock 154 having a high viscosity of from 6 to 30cSt (at 100 ℃), preferably from 8 to 15cSt (at 100 ℃). Both group III base stock fractions have viscosity indices greater than 120, pour points of-15 ℃ and cloud-pour point differences less than 30 ℃.

The process of the present invention has several advantages over typical base oil production processes. Whole petroleum crude oil having a high concentration of waxy hydrocarbons can be effectively upgraded into finished products without the difficulties typically present with waxy hydrocarbons in processing. Because the waxy hydrocarbons are never condensed, the need for heating tanks and transportation lines in the process is eliminated. The finished product can be obtained in essentially two stages-hydroprocessing and catalytic dewaxing. In both stages, the 350 ° f- (176 ℃ -) molecule is upgraded by increasing the octane to a product with sufficiently high octane for direct incorporation into gasoline. The 350F-650F (176 ℃ - & 343 ℃) distillate oil molecules are dewaxed, desulfurized and hydrogenated to ultra low sulfur diesel, and the 650F + (343 ℃ +) molecules are hydroisomerized and hydrogenated to group III basestocks. In addition, the process minimizes distillation since no molecules are vaporized more than once and produces a high viscosity group III base stock product without vaporization.

This ability to produce both fuel and lubricant from whole waxy crude without significant over-conversion or under-conversion of a portion of the feedstock is surprising. The benefits of processing the yield and selectivity of the all-waxy crude compared to separately processing naphtha, distillate, and 650 ° f + (343 ℃ +) fractions are also surprising. Without being bound by theory, it is believed that the stability and selectivity of the dewaxing catalysts described herein are capable of achieving such conversion and achieving a sufficiently flat pour point versus boiling point curve to simultaneously upgrade the naphtha range and the range of 1050 ° f + (565 ℃ +) paraffins. Also, the use of the dewaxing catalyst allows for the simultaneous production of low and high viscosity base stocks meeting or exceeding group III base stock specifications. In addition, the 650 DEG F- (343 ℃ -) component of the feedstock reduces mass transfer limitations in the dewaxing catalyst and allows for C₃The yield of paraffinic molecules is maintained at less than 2 wt%. Less than 25 wt.%, preferably less than 20 wt.%, more preferably less than 15 wt.% and ideally 10 wt.% of the 650F + lube range molecules are converted to 650F- (343 ℃ -) fuel range molecules.

Examples

An all waxy crude oil having the properties listed in table 1 below is provided. The octane number of the 350 DEG F- (176 ℃ -) fraction of the whole waxy crude was 40 and the cloud point of the 350-.

API	52
		wt％H	14.6
wt％200℉+	85
		wt％350℉+	40
wt％650℉+	30
		wt％1050℉+	7
% of aromatic carbon	6.8
		ppm S	100
ppm N	134
		wt% saturated hydrocarbons	88
wt% aromatics	12
		MCRT，wt％	0.25
Ni+V，ppm	1

TABLE 1

The waxy crude oil was subjected to about 1800psig for about 0.4hr on a stacked bed of three commercially available nickel molybdenum sulfided hydroprocessing catalysts^-1LHSV was processed at an initial cycle temperature of about 340 ℃. The 650F. + (343 ℃ +) yield of product was about 28 wt%. Sulfur content of the total liquid product<1ppm and nitrogen content<1 ppm. The effluent of the hydroprocessing was at about 0.675hr on alumina bound ZSM-48 with an alumina to silica ratio of about 70:1 and 0.6 wt% platinum^-1The dewaxing was carried out at LHSV, about 340 ℃ and 1800 psig. The dewaxed effluent was distilled to produce a 1 wt% yield of C₃Paraffin, 44 wt% C with an octane number of 73₄-350 ° f + (176 ℃ +) gasoline, 30 wt% yield ULSD with cetane number 60 and cloud point-20 ℃, and 25% yield 650 ° f + (343 ℃ +) base stock.

650F. + (343 ℃ +) base stock over alumina bound MCM-41 catalyst with 0.3 wt% palladium and 0.9 wt% platinum for about 1.0hr^-1LHSV, about 220 deg.C and 1800psig was processed to yield a negligible 650F. - (343 deg.C. -) product. The hydrofinished 650F. + (343 ℃ +) base stock is distilled into two cuts-66 wt% of a light neutral group III base stock of 4cSt (at 100 ℃) with a viscosity index of 122 and a pour point of-40F., and 34 wt% of a heavy neutral group III base stock of 8cSt (at 100 ℃) with a viscosity index of 128 and a pour point of-20F.

The process of the present invention produces 25 wt% of a 650F + (343 ℃ +) group III base stock product-meaning 83% of the 650F + (343 ℃ +) molecules in the crude feed are retained. More than half of the 17% conversion of the 650F + (343 ℃ +) molecule to the 650F- (343 ℃ -) molecule is from paraffin isomerization (n-C)₂₀Conversion of the molecule to trimethyl C₁₇Molecule) and aromatic saturation (with C)₆To C₈Hydrogenation of naphthalene in the side chain to decalin with an unchanged side chain structure). The octane of the 350 DEG F- (176℃ -) fraction is greatly improved, from the initial octane 40 of the feedstock, octane 40 making it unsuitable for blending into gasoline, to reach an octane 73 in the product, octane 73Suitable for incorporation into gasoline without further processing. The 350 DEG F- (176 ℃ -) fraction (naphtha) is also sulfur-free. The 350F-650F (176-.

All patents, test procedures, and other documents cited herein, including priority documents, are fully incorporated by reference to the extent such disclosure is not inconsistent with and for all jurisdictions in which such incorporation is permitted.

Although the illustrative forms disclosed herein have been described in detail, it should be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the scope of the claims herein be limited to the examples and descriptions set forth herein but rather that the claims be construed as encompassing all the patentable novel features presented herein, including all the features which would be treated as equivalents thereof by those skilled in the art to which the disclosure pertains.

When numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.

Claims

1. A method of producing a lubricant base oil from whole petroleum crude oil, the method comprising:

a. providing a whole petroleum crude oil feedstock comprising less than about 2 wt% heptane asphaltenes, less than about 2 wt% Conradson Carbon Residue (CCR) and less than about 50ppm metals;

b. hydrotreating said whole petroleum crude oil feedstock over at least one hydrotreating catalyst bed under effective hydrotreating conditions to produce a hydrotreated effluent having less sulfur, nitrogen, and aromatics than said whole petroleum crude oil;

c. dewaxing the hydrotreated effluent in the presence of a dewaxing catalyst to produce a naphtha product having an octane number greater than 60, a diesel product having a cloud point below 0 ℃, and a lubricant base oil product; and

d. fractionating the lubricant base oil product into at least a low viscosity lubricant base oil product having a viscosity of 2-8cSt at 100 ℃ and a high viscosity lubricant base oil product having a viscosity of 6-30cSt at 100 ℃.

2. The method of claim 1, wherein the low viscosity lubricant base oil product and the high viscosity lubricant base oil product have a viscosity index of at least 120, a pour point of about-15 ℃, and less than 300ppm sulfur.

3. The process of claim 1 or 2, wherein the octane number of the naphtha product is greater than 70.

4. The process of any of claims 1-3, wherein the diesel product comprises less than 15ppm sulfur and has a pour point below 0 ℃.

5. The process of any of claims 1-4, wherein the whole petroleum crude oil feedstock comprises less than 0.5 wt% heptane asphaltenes, less than 20ppm sulfur and nitrogen, and less than 1 wt% carbonaceous residue.

6. The process of any of claims 1-5, wherein at least two beds of hydrotreating catalyst are used in step (b), and the hydrotreating catalyst comprises at least one group VIII non-noble metal and at least one group VI metal.

7. The process of claim 6, wherein the group VIII non-noble metal is selected from Fe, Co and/or Ni and the group VI metal is selected from Mo and/or W.

8. The method of any of claims 1-7, wherein the hydrotreated effluent comprises less than 15ppm sulfur, less than 5ppm nitrogen, less than 2 wt% C₃Paraffins and less than 25 wt% aromatics.

9. The process of any of claims 1-8, wherein the dewaxing catalyst of step (c) comprises ZSM-48, the ZSM-48 having a silica to alumina ratio of about 100:1 or less and 0.5 to 1.0 wt% group VIII noble metal.

10. The process of any of claims 1-9, further comprising hydrofinishing the lubricant base oil product to remove polynuclear aromatic compounds prior to step (d).

11. The method of any of claims 1-10, wherein the low viscosity lubricant base oil product has a viscosity of 3-5cSt at 100 ℃ and the high viscosity lubricant base oil product has a viscosity of 8-15cSt at 100 ℃.

12. A process for producing a naphtha product, a diesel product, and a lubricant base oil product from whole petroleum crude oil, the process comprising:

a. providing a whole petroleum crude oil feedstock to a hydroprocessing unit without separation or pretreatment, wherein the feedstock comprises less than about 2 wt% heptane asphaltenes, less than about 2 wt% Conradson Carbon Residue (CCR) and less than about 50ppm metals;

b. hydrotreating said whole petroleum crude oil feedstock over at least one hydrotreating catalyst bed under effective hydrotreating conditions to produce a hydrocarbon feedstock having less than 15ppm sulfur, less than 5ppm nitrogen, less than 2 wt% C₃-a hydrotreated effluent of paraffins and less than 25 wt% of aromatics;

c. dewaxing the hydrotreated effluent in the presence of a dewaxing catalyst to produce a dewaxed effluent;

d. separating the dewaxed effluent into at least a naphtha product having an octane number greater than 60, a diesel product having a cloud point below 0 ℃, and a base stock product;

e. hydrofinishing and/or aromatic saturation of the base stock product to remove polynuclear aromatics and produce a hydrofinished base stock; and

f. fractionating the hydrofinished base stock into at least a low viscosity lubricant base oil product having a viscosity of from 2 to 8cSt at 100 ℃ and a high viscosity lubricant base oil product having a viscosity of from 6 to 30cSt at 100 ℃.

13. The method of claim 12, wherein the low viscosity lubricant base oil product and the high viscosity lubricant base oil product have a viscosity index of at least 120, a pour point of about-15 ℃, and less than 300ppm sulfur.

14. The method of claim 12 or 13, wherein the low viscosity lubricant base oil product has a viscosity of 3-5cSt at 100 ℃ and the high viscosity lubricant base oil product has a viscosity of 8-15cSt at 100 ℃.

15. The process of any one of claims 12-14, wherein the naphtha product has an octane number greater than 70.

16. The process of any of claims 12-15, wherein the diesel product comprises less than 15ppm sulfur and has a pour point below 0 ℃.

17. The method of any one of claims 12-16, wherein the whole petroleum crude oil feedstock comprises less than 0.5 wt% heptane asphaltenes, less than 20ppm sulfur and nitrogen, and less than 1 wt% carbonaceous residue.

18. The process of any of claims 12-17, wherein at least two beds of hydrotreating catalyst are used in step (b), and the hydrotreating catalyst comprises at least one group VIII non-noble metal and at least one group VI metal.

19. The process of claim 18, wherein the group VIII non-noble metal is selected from Fe, Co, and/or Ni, and the group VI metal is selected from Mo and/or W.

20. The process of any of claims 12-19, wherein the dewaxing catalyst of step (c) comprises ZSM-48, the ZSM-48 having a silica to alumina ratio of about 100:1 or less and 0.5 to 1.0 wt% of a group VIII noble metal.