US20070278134A1

US20070278134A1 - Process for producing light neutral base oil having a high viscosity index

Info

Publication number: US20070278134A1
Application number: US11/445,997
Authority: US
Inventors: Hye Kyung Timken; Jerome F. Mayer; Arthur J. Dahlberg; Andrew Rainis
Original assignee: Chevron USA Inc
Current assignee: Chevron USA Inc
Priority date: 2006-06-01
Filing date: 2006-06-01
Publication date: 2007-12-06
Also published as: WO2007143435A3; WO2007143435A2; WO2007143435A9

Abstract

A process is disclosed for producing light neutral base oil having a VI greater than 120 comprising the steps of contacting a hydrocarbonaceous feedstock with a catalyst comprising a low acidity, highly dealuminated ultrastable Y zeolite and a catalytic amount of hydrogenation component to produce a converted fraction and an unconverted fraction boiling above 700° F.; recovering at least a portion of the unconverted fraction; dewaxing at least a portion of the unconverted fraction; separating at least a portion of the dewaxed unconverted fraction into a least a first distillate fraction and a second distillate fraction, said first distillate fraction comprising a lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C. and said second distillate fraction having a viscosity of greater than about 6 cSt at 100° C.; and recovering at least a portion of the first distillate fraction.

Description

FIELD OF THE INVENTION

The present invention relates to the production of base oils from the hydrocracking of hydrocarbonaceous feedstocks.

BACKGROUND OF THE INVENTION

Finished lubricants used for automobiles, diesel engines, axles, transmissions, and industrial applications consist of two general components, a lubricating base oil and additives. Lubricating base oil is the major constituent in these finished lubricants and contributes significantly to the properties of the finished lubricant. In general, a few lubricating base oils are used to manufacture a wide variety of finished lubricants by varying the mixtures of individual lubricating base oils and individual additives.
Modern engines and transmissions require base oils with high temperature stability, low temperature performance, and low volatility. New engine and transmission technology will push the base oils to even higher quality. Polyalphaolefins (PAOs) have historically been the benchmark highest quality base stock. However, highly paraffinic petroleum-derived base oils have been developed that can nearly equal the performance of PAOs and at much lower cost. Base oils with volatility nearly as low as PAO can be made by increasing viscosity index (VI) and controlling the distillation. Base oils with excellent low temperature properties, such as cold cranking simulator viscosity (CCS) and Brookfield viscosity, can be made so that they perform nearly as well as PAOs. Very high VI and low viscosity are required to achieve excellent low temperature performance. Such base oils are produced in accordance with the present invention.

SUMMARY OF THE INVENTION

The present invention provides, among other things, a process for producing light neutral base oil having a VI greater than 120 comprising: contacting a hydrocarbonaceous feedstock with a catalyst comprising a low acidity, highly dealuminated ultrastable Y zeolite and a catalytic amount of hydrogenation component to produce a converted fraction and an unconverted fraction boiling above 700° F.; recovering at least a portion of the unconverted fraction; dewaxing at least a portion of the unconverted fraction; separating at least a portion of the dewaxed unconverted fraction into a least a first distillate fraction and a second distillate fraction, said first distillate fraction comprising a lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C. and said second distillate fraction having a viscosity of greater than about 6 cSt at 100° C.; and recovering at least a portion of the first distillate fraction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a VI droop curve comparing three equal volume cuts of an unconverted fraction using three different hydrocacking catalysts.

FIG. 2 is a plot of VI as a function of viscosity for catalytically dewaxed products.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Feedstock

Examples of hydrocarbonaceous feedstocks which can be used comprise gas oils, vacuum gas oils, deasphalted oils, long residues, catalytically cracked cycle oils, coker gas oils and other thermally cracked gas oils and syncrudes, optionally originating from tar sands, shale oils, waxy hydrocarbons from Fischer-Tropsch hydrocarbon synthesis process, residue upgrading processes or biomass. Combinations of various feedstocks can also be used.
It may be desirable to subject part or all of the feedstock to one or more (hydro) treatment steps prior to its use in the hydrocarbon conversion process according to the present invention. It is often found convenient to subject the feedstock to a (partial) hydrotreatment. When rather heavy feedstocks are to be processed it will be advantageous to subject such feedstocks to a (hydro) demetallization treatment.

Catalysts

The catalysts used in the hydrocracking stage in accordance with the present invention comprise an ultrastable Y zeolite having low acidity. Low acidity ultra stable Y zeolites and catalyst compositions which may be used in the present invention are disclosed in U.S. Pat. Nos. 6,860,986 and 6,902,664, which are incorporated by reference herein.
The use of a catalyst composition comprising a low acidity ultrastable Y zeolite was found to produce an unexpectedly high VI advantage in the low viscosity region of the unconverted fraction from the hydrocracking stage.
In accordance with the one embodiment of the present invention, the catalyst comprises (1) a minor amount of a low acidity, highly dealuminated ultrastable Y zeolite having an Alpha value of less than about 5, preferably less than about 3, and Broensted acidity of from about 1 to about 20, preferably about 1-10 micromole/g, and a catalytic amount of hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal, and mixtures thereof.
The amount of highly dealuminated USY zeolite in the catalyst compositions on a finished catalyst basis including metals ranges from about 0.5-70% by weight, preferably, from about 0.5-50% and most preferably from about 1-30%.
Highly dealuminated USY zeolites having a silica to alumina molar ratio greater than 50 are useful as the zeolite component of the catalyst compositions according to the present invention. Preference is given to USY zeolites having a silica: alumina molar ratio greater 60, and most preferably having silica: alumina molar ratio greater than 80.
Due to the extremely low acidity of the USY, the hydrocracking catalysts may benefit from the addition of a secondary amorphous cracking component. Preferably, silica-alumina based amorphous cracking components are used. However, other amorphous cracking components that are well known in the art can be used. These include, but are not limited to, magnesia, zirconia, titania, silica, and alumina. Silica-alumina is the preferred amorphous cracking component. The most preferred amorphous cracking components are those highly homogeneous, amorphous silica-alumina compositions described in U.S. Pat. No. 6,995,112, which is incorporated by reference herein.
Consequently, the catalysts of the present invention also include an amorphous cracking component which comprises a homogeneous, amorphous silica-alumina cracking component having an SB ratio (Surface-to-Bulk ratio, as defined in U.S. Pat. No. 6,995,112) of from about 0.7 to about 1.3, wherein a crystalline alumina phase is present in an amount of no greater than about 10%, preferably no greater than 5%. A silica-alumina in accordance with the present invention has an SB ratio of from about 0.7 to about 1.3, preferably from about 0.9 to about 1.1 and is homogeneous and highly homogeneous, respectively, in that the aluminum is distributed essentially uniformly throughout the particles. To maximize the activity of the silica-alumina, it is most preferable to have a highly homogeneous silica-alumina having an SB ratio of about 1.0. These silica-alumina compositions are also amorphous, wherein a crystalline alumina phase, such as pseudoboehmite phase, is present in an amount no greater than about 10%, preferably no greater than about 5%.
Silica-alumina according to the present invention may be prepared by a variety of methods employing batch and continuous processes in different combinations. A preferred method is described in U.S. Pat. No. 6,872,685, which is incorporated by reference herein.
The amount of amorphous cracking component in the catalyst compositions on a finished catalyst basis including metals, ranges from about 10%-80% by weight, preferably from about 30%-70% by weight and most preferably from about 40%-60%. The amount of silica in the silica-alumina ranges from about 10%-70% by weight. Preferably, the amount of silica in the silica-alumina ranges from about 20%-60% by weight, and most preferably the amount of silica in the silica-alumina ranges from about 25%-50% by weight.
Catalyst compositions useful in the present invention may also comprise one or more binders. The binder(s) present in the catalyst compositions suitably comprise inorganic oxides. Both amorphous and crystalline binders can be applied. Examples of suitable binders comprise silica, alumina, clays and zirconia. Preference is given to the use of alumina as binder. The amount of binder in the catalyst compositions in accordance with the present invention on a finished catalyst basis including metals ranges 10%-30% by weight, and is preferably from about 15%-25% by weight.
The catalyst compositions also comprise a hydrogenation component. As used herein the hydrogenation component mainly means metals of Group VI and VIII in the Periodic Table, for example, chromium, molybdenum, tungsten, iron, cobalt, nickel, platinum, palladium, and the like metals and oxides and sulfides of these metals. These metals may be used in combination of two or more members. For example, combinations of metals such as nickel-tungsten, nickel-molybdenum cobalt-molybdenum, platinum-palladium, and the like may be used.
The amount(s) of hydrogenation component(s) in the catalyst compositions suitably range from about 0.2% to about 10% by weight of Group VIII metal component(s) and from about 5% to about 30% by weight of Group VI metal component(s), calculated as metal(s) per 100 parts by weight of total catalyst. The hydrogenation components in the catalyst compositions may be in the oxidic and/or the sulphidic form. If a combination of at least a Group VI and a Group VIII metal component is present as (mixed) oxides, it will be subjected to a sulphiding treatment prior to proper use in hydrocracking.
A preferred catalyst composition comprises about 1%-10% by weight of nickel and about 5%-40% by weight tungsten. Preferably, the catalyst compositions comprise about 2%-8% by weight of nickel and about 8%-30% by weight tungsten, calculated as metals per 100 parts by weight of total catalyst.
When noble metal is used, the catalyst compositions generally comprise about 0.1%-5% by weight of platinum, or palladium, or a combination of Pt and Pd. Preferably, the catalyst compositions comprise about 0.2%-2% by weight of platinum, or palladium, or a combination of Pt and Pd, calculated as metals per 100 parts by weight of total catalyst.

Hydrocracking Conditions

Suitable hydrocracking conditions to be applied comprise temperatures ranging from about 250° C. to about 500° C., pressures up to about 300 bar and space velocities from about 0.1 to about 10 kg feed per liter of catalyst per hour (kg/l/h). Hydrogen gas to feed ratios range from about 100 to about 5000 Nl/kg feed (normal liters at standard temperature and pressure per kilogram) can suitably be used.
Preferably, hydrocracking conditions to be applied comprise temperatures ranging from about 300° C. to about 450° C., pressures from about 25 bar to about 200 bar and space velocities from about 0.2 to about 10 kg feed per liter of catalyst per hour (kg/l/h). Hydrogen gas to feed ratios preferably range from about 250 to about 2000 Nl/kg are applied.
Hydrocracking the feed produces a converted fraction and an unconverted fraction boiling above 700° F. The unconverted fraction or unconverted oil (UCO) is recovered by distillation.

Separation by Distillation

The unconverted fraction is separated, either before or after dewaxing, by another distillation step into at least a first distillate fraction and a second distillate fraction. If this separation occurs after dewaxing, the first distillate fraction comprises a lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C. and the second distillate fraction having a viscosity of greater than about 6 cSt at 100° C. It is also possible in accordance with the invention to select narrower cut distillations to achieve lubricating base oil viscosity ranges of about 3-4 cSt, 4-5 cSt, and 5-6 cSt.
If the separation of the unconverted fraction occurs before dewaxing, the unconverted fraction is separated by further distillation to generate a first distillate fraction of unconverted oil boiling in the range of about 700° F.-850° F. and a second fraction boiling above 850° F. at atmospheric pressure. In this case, the 700° F.-850° F. fraction is dewaxed to generate lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C. It is also possible to select narrower cut distillations to achieve lubricating base oil viscosity ranges of about 3-4 cSt, 4-5 cSt, and 5-6 cSt, by removing fractions boiling in the ranges of about 700° F.-780° F., 780° F.-860° F., 860° F.-920° F., respectively.

Dewaxing

Dewaxing the unconverted fraction follows hydrocracking. The unconverted fraction may be dewaxed before or after separation into distillate fractions. A two-stage process using catalytic dewaxing following hydrocracking and typical hydrocracking conditions are described in U.S. Pat. No. 4,921,594, which is incorporated herein by reference. Dewaxing in accordance with the present invention may also be accomplished by a solvent dewaxing process.
Catalytic dewaxing operations suitable for use in the present invention typically use a catalyst comprising an acidic component and may optionally contain an active metal component having hydrogenation activity. The acidic component of the catalysts preferably include an intermediate pore SAPO, such as SAPO-11, SAPO-31, and SAPO-41, with SAPO-11 being particularly preferred. Intermediate pore zeolites, such as ZSM-22, ZSM-23, SSZ-32, ZSM-35, and ZSM-48, also may be used in carrying out the dewaxing. Typical active metals include molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum, and palladium. The metals platinum and palladium are especially preferred as the active metals, with platinum most commonly used.
The phrase “intermediate pore size”, when used herein, refers to an effective pore aperture in the range of from about 5.3 to about 6.5 Angstrom when the porous inorganic oxide is in the calcined form. Molecular sieves having pore apertures in this range tend to have unique molecular sieving characteristics. Unlike small pore zeolites such as erionite and chabazite, they will allow hydrocarbons having some branching into the molecular sieve void spaces. Unlike larger pore zeolites such as faujasites and mordenites, they are able to differentiate between n-alkanes and slightly branched alkenes, and larger alkanes having, for example, quaternary carbon atoms. See U.S. Pat. No. 5,413,695. The term “SAPO” refers to a silicoaluminophosphate molecular sieve such as described in U.S. Pat. Nos. 4,440,871 and 5,208,005.
In preparing those catalysts containing a non-zeolitic molecular sieve and having an hydrogenation component, it is usually preferred that the metal be deposited on the catalyst using a non-aqueous method. Non-zeolitic molecular sieves include tetrahedrally-coordinated [AIO2 and PO2] oxide units which may optionally include silica. See U.S. Pat. No. 5,514,362. Catalysts containing non-zeolitic molecular sieves, particularly catalysts containing SAPO's, on which the metal has been deposited using a non-aqueous method have shown greater selectivity and activity than those catalysts which have used an aqueous method to deposit the active metal. The non-aqueous deposition of active metals on non-zeolitic molecular sieves is taught in U.S. Pat. No. 5,939,349. In general, the process involves dissolving a compound of the active metal in a non-aqueous, non-reactive solvent and depositing it on the molecular sieve by ion exchange or impregnation.
The catalytic dewaxing conditions are dependent in large measure on the feed used and upon the desired pour point. Hydrogen is preferably present in the reaction zone during the catalytic dewaxing process. The hydrogen to feed ratio is typically between about 500 and about 30,000 SCF/bbl (standard cubic feet per barrel), preferably about 1000 to about 20,000 SCF/bbl. Generally, hydrogen will be separated from the product and recycled to the reaction zone.
Solvent dewaxing attempts to remove the waxy molecules from the product by dissolving them in a solvent, such as methyl ethyl ketone, methyl iso-butyl ketone, or toluene, and precipitating the wax molecules and then removing them by filtration as discussed in Chemical Technology of Petroleum, 3rd Edition, William Gruse and Donald Stevens, McGraw-Hill Book Company, Inc., New York, 1960, pages 566-570. See also U.S. Pat. Nos. 4,477,333; 3,773,650; and 3,775,288. In general, with the present invention catalytic dewaxing is usually preferred over solvent dewaxing, since it results in higher viscosity index products with improved low temperature properties, and in higher yields of the products boiling within the range of the first and second distillate fractions.
The following Examples are illustrative of the present invention, but are not intended to limit the invention in any way beyond what is contained in the claims which follow.

EXAMPLE 1

Preparation of NiW USY Hydrocracking Catalyst (Catalyst A-Invention)

A hydrocracking catalyst containing low acidity USY was prepared per following procedure. USY having Alpha values of less than 5, and 1-20 micro mole/g of Broensted acidity measured by FT-IR were used. 8 parts USY, 67 parts silica-alumina powder and 25 parts pseudoboehmite alumina powder were mixed well. To the mix, diluted HNO₃acid and sufficient amount of deionized water were added to form an extrudable paste (3 wt % HNO₃to the total powders). These weights are on 100% solids basis. The paste was extruded in 1/16″ cylinder, and dried at 250° F. overnight. The dried extrudates were calcined at 1100° F. for 1 hr with purging excess dry air, and cooled down to room temperature.
Impregnation of Ni and W was done using a solution containing ammonium metatungstate and nickel nitrate to the target metal loadings of 4 wt % NiO and 28 wt % WO₃in the finished catalyst. The total volume of the solution matched the 100% water pore volume of the base extrudate sample (incipient wetness method). The metal solution was added to the base extrudates gradually while tumbling the extrudates. When the solution addition was complete, the soaked extrudates were aged for 2 hours. Then the extrudates were dried at 250° F. overnight. The dried extrudates were calcined at 935° F. for 1 hr with purging excess dry air, and cooled down to room temperature. This catalyst is named Catalyst A.

EXAMPLE 2

Preparation of Hydrocracking Catalysts with Low Acidity USY and Homogeneous Silica-Alumina Sample (Catalyst B-Invention)

Catalyst B, a NiW catalyst useful for this invention, containing USY with Alpha values of less than 5, and 1-20 micro mole/g of Broensted acidity measured by FT-IR and highly homogeneous amorphous silica-alumina having a surface to bulk silica to alumina ratio (SB ratio) of from about 0.7 to about 1.3, and a crystalline alumina phase present in an amount no more than about 10%, was prepared using a procedure similar to Catalyst A. For Catalyst B, 3 parts USY, 72 parts silica-alumina and 25 parts pseudoboehmite alumina powder were used to prepare the base extrudates. Then Ni and W were loaded via impregnation as described in the Example 1. The target metal loadings were 4 wt % NiO and 28 wt % WO₃.

Feedstock for Catalyst Performance Evaluation

A petroleum feedstock with the following properties shown in Table 1 was used to evaluate the catalysts.

TABLE 1

Feedstock Properties

	Properties
	API Gravity	33.7
	Sulfur, ppm wt	7
	Nitrogen, ppm	0.7
	wt
	D2887 Simdis, F
	Start Point	645
	10 wt %	707
	30 wt %	769
	50 wt %	826
	70 wt %	890
	90 wt %	977
	End Point	1079

EXAMPLE 3

Comparison of Hydrocracking Catalyst Performance for Lube Base Oil Production after Solvent Dewaxing (Cogel Catalyst vs. Catalysts A and B)

Catalysts A and B of our invention were compared with Catalyst C, which is a state-of-the-art cogel catalyst not containing any low acid USY using a hydrocracking process in a recycle pilot unit.
Recycling hydrocracking pilot unit evaluations were done with 130 cc of extrudate catalyst by recycling part of the unconverted 700° F. bottom and H₂gas. Fresh feed was added to the recycled feed and the feed rate was adjusted to maintain 34 vol % pre-pass conversions. Fresh make-up H₂gas was added to the recycled H₂gas stream to maintain 5000 SCF/bbl of recycled gas flow. Process conditions were:
Pressure: 2300 psig

LHSV: 1.0 hr⁻¹

Per-pass conversion of fresh feed: 34%

Inlet H2: 5000 SCF/bbl

˜43% of 700° F.+ unconverted oil was bled from the distillation column to examine the potential for a lube base stock production. Waxy viscosity index (VI) was measured for the 700° F.+ UCO as-is. Solvent dewaxing was done at −10° C. and dewaxed VI was measured. The overall yields and VI and viscosity data were summarized in Table 2.
The solvent dewaxed VI data indicate the catalysts of our invention (Catalysts A and B) show 2 numbers of dewaxed VI number advantage over Catalyst C.

TABLE 2

Performance of Catalysts for Lube Base Stock Production

Catalyst

	Catalyst C	Catalyst A	Catalyst B

700° F.+ UCO
Waxy Viscosity Index	136	145	147
Solvent Dewaxing of 700° F.+ UCO
Solvent DWO Viscosity Index	131	133	133
Viscosity @ 100° C., cSt	4.85	5.01	4.99

When the solvent-dewaxed UCO was cut into three equal fractions to determine VI of various viscosity fractions, it was surpassing to find that the catalysts according to the invention exhibit far significant VI advantage for 3-5 cSt viscosity range at 100° C. The results are plotted in the FIG. 1. At 4.2 cSt (at 100° C.), Catalyst A exhibits 7-8 VI number advantage over Catalyst C. Catalyst B exhibits an advantage of 5 VI number over Catalyst C.

EXAMPLE 4

Comparison of HCR Catalyst Performance for Lube Base Oil Production after Catalytic Dewaxing (Catalyst C vs. Catalyst B)

We compared the effect of hydrocracking catalysts on dewaxed lube base oil after catalytic dewaxing. The 700° F.+ UCO samples generated by hydrocracking using the Catalyst C and Catalyst B were dewaxed using noble-metal containing medium pore shape selective zeolite catalyst. The dewaxing catalyst temperature was adjusted to produce −18° C. pour point product at 1.0 liquid hourly space velocity, 2100 psia hydrogen partial pressure and once through hydrogen rate of 3000 SCFB.
The results summarized in Table 3 indicate that both hydrocracking catalyst/dewaxing catalyst combinations show the same VI number for the total 700° F.+ UCO.

TABLE 3

Results for Catalytic Dewaxing of Hydrocracked UCO

HCR Catalyst

	Catalyst B	Catalyst C

Dewaxing Catalyst	Noble Metal Shape	Noble Metal Shape
	Selective Catalyst	Selective Catalyst
Dewaxed Oil Properties
Vis @ 100° C., cSt.	5.088	4.877
VI	133	133

Each product from the catalytic dewaxing was distilled into three fractions and then analyzed for viscosity and VI, as shown in Tables 4 and 5. When the dewaxed oil was cut into three fractions, surprisingly a significant advantage of VI number for 3-5 cSt region at 100° C. was observed. VI advantage at 4 cSt region was estimated as 4 VI numbers (FIG. 2).
The result is especially unexpected because the VI_sfor the total UCO fractions were the same for Catalysts B and C.

TABLE 4

Product Properties of Catalytically Dewaxed Oil
from Hydrocracked UCO with Catalyst B

HCR Catalyst

	Catalyst B	Catalyst B	Catalyst B

Catalytic Dewaxing	Noble Metal	Noble Metal	Noble Metal
Catalyst	Shape Selective	Shape Selective	Shape Selective
	Catalyst	Catalyst	Catalyst
Cut Number	1	2	3
Cut Boiling Range	St–797° F.	797–902° F.	902° F.+
API Gravity	38.6	37.9	36.2
Vis @ 100° C., cSt.	3.715	5.08	9.01
VI	119	132	138

TABLE 5

Product Properties of Catalytically Dewaxed Oil
from Hydrocracked UCO Catalyst C

HCR Catalyst

	Catalyst C	Catalyst C	Catalyst C

Catalytic Dewaxing	Noble Metal	Noble Metal	Noble Metal
Catalyst	Shape Selective	Shape Selective	Shape Selective
	Catalyst	Catalyst	Catalyst
Cut Number	1	2	3
Cut Boiling Range	St–789° F.	789–900° F.	900° F.+
API Gravity	38.7	38.3	36.5
Vis @ 100° C., cSt.	3.547	4.931	9.010
VI	114	130	138

A plot of the VI data in Tables 4 and 5 as shown in FIG. 2. VI advantage at 4 cSt region was estimated as 4 VI numbers.

Claims

1. A process for producing light neutral base oil having a VI greater than 120 comprising:

(a) contacting a hydrocarbonaceous feedstock with a catalyst comprising a low acidity, highly dealuminated ultrastable Y zeolite having an Alpha value of less than about 5 and Broensted acidity of from about 1 to about 20 micromole/g measured by FT-IR and a catalytic amount of hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal, and mixtures thereof under hydrocracking conditions to produce a converted fraction and an unconverted fraction boiling above 700° F.;

(b) recovering at least a portion of the unconverted fraction;

(c) dewaxing at least a portion of the unconverted fraction;

(d) separating at least a portion of the dewaxed unconverted fraction into a least a first distillate fraction and a second distillate fraction, said first distillate fraction comprising a lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C. and said second distillate fraction having a viscosity of greater than about 6 cSt at 100° C.; and

(e) recovering at least a portion of the first distillate fraction.

2. A process according to claim 1, wherein said first distillate fraction has a viscosity of from about 3 cSt to about 4 cSt at 100° C.

3. A process according to claim 1, wherein said first distillate fraction has a viscosity of from about 4 cSt to about 5 cSt at 100° C.

4. A process according to claim 1, wherein said first distillate fraction has a viscosity of from about 5 cSt to about 6 cSt at 100° C.

5. A process according to claim 1, wherein the catalyst further comprises a homogeneous, amorphous silica-alumina cracking component having an SB ratio of from about 0.7 to about 1.3, wherein a crystalline alumina phase is present in an amount of no greater than about 10%, preferably no greater than 5%.

6. A process according to claim 1, wherein the dewaxing is catalytic dewaxing.

7. A process according to claim 1, wherein the catalyst comprises from about 0.5% to 30% by weight of ultrastable Y zeolite, from about 10% to 80% by weight of amorphous cracking component, and from about 10% to 30% by weight of a binder.

8. A process according to claim 1, wherein the Group VIII metal hydrogenation component is selected from the group consisting of nickel, cobalt, platinum, palladium and mixtures thereof and wherein the Group VI metal hydrogenation component is selected from the group consisting of molybdenum, tungsten and mixtures thereof.

9. A process according to claim 8, wherein the hydrogenation component comprises from about 2% to about 8% by weight of nickel and from about 8% to about 30% by weight of tungsten, calculated as metals per 100 parts by weight of total catalyst.

10. A process according to claim 8, wherein the hydrogenation component comprises from 0.2% to about 2% by weight of platinum, or from about 0.2% to about 2% by weight of palladium, or a combination of from 0.2% to about 2% by weight of platinum and palladium, calculated as metals per 100 parts by weight of total catalyst.

11. A process for producing light neutral base oil having a VI greater than 120 comprising:

(b) recovering at least a portion of the unconverted fraction;

(c) separating at least a portion of the recovered unconverted fraction into a least a first distillate fraction and a second distillate fraction, said first distillate fraction boiling in the range of about 700° F.-850° F. and said second distillate fraction boiling above 850° F. at atmospheric pressure;

(d) dewaxing at least a portion of the first distillate fraction; and

(e) recovering at least a portion of the dewaxed first distillate fraction comprising a lubricating base oil having a viscosity of from about 3 cSt to about 6 cSt at 100° C.

12. A process according to claim 11, wherein the first distillate fraction boils in the range of about 700° F.-780° F. and the lubricating base oil has a viscosity of from about 3 cSt to about 4 cSt at 100° C.

13. A process according to claim 11, wherein the first distillate fraction boils in the range of about 780° F.-860° F. and the lubricating base oil has a viscosity of from about 4 cSt to about 5 cSt at 100° C.

14. A process according to claim 11, wherein the first distillate fraction boils in the range of about 860° F.-920° F. and the lubricating base oil has a viscosity of from about 5 cSt to about 6 cSt at 100° C.

15. A process according to claim 11, wherein the catalyst further comprises a homogeneous, amorphous silica-alumina cracking component having an SB ratio of from about 0.7 to about 1.3, wherein a crystalline alumina phase is present in an amount of no greater than about 10%, preferably no greater than 5%.

16. A process according to claim 11, wherein the dewaxing step is catalytic dewaxing.

17. A process according to claim 11, wherein the catalyst comprises from about 0.5% to 30% by weight of ultrastable Y zeolite, from about 10% to 80% by weight of amorphous cracking component, and from about 10% to 30% by weight of a binder.

18. A process according to claim 11, wherein the Group VIII metal hydrogenation component is selected from the group consisting of nickel, cobalt, platinum, palladium and mixtures thereof and wherein the Group VI metal hydrogenation component is selected from the group consisting of molybdenum, tungsten and mixtures thereof.

19. A process according to claim 18, wherein the hydrogenation component comprises from 2% to about 8% by weight of nickel and from about 8% to about 30% by weight of tungsten, calculated as metals per 100 parts by weight of total catalyst.

20. A process according to claim 18, wherein the hydrogenation component comprises from 0.2% to about 2% by weight of platinum, or from about 0.2% to about 2% by weight of palladium, or a combination of from 0.2% to about 2% by weight of platinum and palladium, calculated as metals per 100 parts by weight of total catalyst.