SG175587A1

SG175587A1 - Isomerization process using metal-modified small crystallite mtt molecular sieve

Info

Publication number: SG175587A1
Application number: SG2011072329A
Authority: SG
Inventors: Stacey I Zones; Kamala Krishna
Original assignee: Chevron Usa Inc
Priority date: 2006-10-04
Filing date: 2007-10-03
Publication date: 2011-11-28
Also published as: RU2009116476A; MX2009003522A; BRPI0717481A2; JP2010506010A; EP2074199A2; CN103031144A; US20080083657A1; WO2008042979A2; CA2662817A1; KR101385333B1; KR20090078336A; WO2008042979A3; RU2493236C2

Abstract

Dewaxing a hydrocarbon feed by isomerizing feed with catalyst comprising small crystallite molecular sieve craving MTT framework, the catalyst containing at least one metal selected from the group consisting of Ca, Cr, Mg, La, Na, Pr, Sr, K and Nd, and at least one Group VIII metal. A dewaxing method to produce productsboiling at 343[err]C (650[err]F) or higher with low pour points (X-axis) and high viscosity indexes wherein the line fit to the chart of the pour points and the viscosity indexes has a slope of zero or less. A dewaxing process, comprising isomerization dewaxing feed with a viscosity at 100[err]C of 2.5 mm[err]/s or greater ever a metal-modified molecular sieve (SSZ-32 and SSZ-32X) to produceproducts with low pour points (X-axis) and high viscosity indexes: the line fit to the chart of the pour points and the viscosity indexes has a slope of zero or less: and wherein the yield of products is high (figure 1).(Figure 1)

Description

ISOMERIZATION PROCESS USING METAL-MODIFIED

SMALL CRYSTALLITE MTT MOLECULAR SIEVE

HELD OF THE INVENTION

:

This invention is directed to 8 process for isomerizing a feed which includes straight chain and slightly branched paraffins having 10 or more carbon atoms using a catalyst comprising a small crystallite MTT molecular sieve loaded with metals. This invention is also directed to dewaxing methods producing products with improved viscosity indexes at lower pour points.

BACKGROUND OF THE INVENTION

The production of Group if and Group il base oils employing hydroprocessing has become increasingly poputar in recent years.

Catalysts that demonstrate improved isomerization selectivity and conversion are continually sought. As discussed in U.S. Pal. No. 5,282,958, gol. 1-2, the use of intermediate pore molecular sieves such as ZSM-22

Z8M-23, ZSM-38, S8Z-32, BAPO-11, BAPO-31, 8M-3, SM-B in somerization and shape-selective dewaxing is well-known, Other typical zeolites useful in dewaxing include ZSM-48, ZSM-57, 88Z-20,EU-I, EU-13, ferrigsite, SUZ-4, theta-1, NU-10, NU-23, NU-B7 I8I-1, 1814, KZ-1 and KZ-2.

U.S Pat. No, 5,252,827 and 5,083,373 disclose a zeolite such as $8Z-32 which is prepared using an N-tower alkyl-N-isopropyl-imidazolium cation as a empiate. 5,053,373 discloses 2 silica to alumina ratio of greater than 20 io less than 40 and a constraint index, after calcination and in the hvdrogen form, of 13 or greater. The zeolite of 5 252 527 is not restricted to a constraint index of 13 or greater. 5,252 627 discloses loading zeolites with matals in order to provide a hydrogenation- dehydrogenation function. Typical replacing gations can include hydrogen, ammonium, meta! cations, e.g., rare earth,

Group liA and Group Vill metals, as well as their mixtures. A method for preparation of MT T-type zeolites such as S8Z.32 or Z5M-23 using small neutral amines is disclosed in U.S. Pat. No. 5,707 801.

U.S. Pat. No. £397 454 discloses hydroconversion processes employing a & zeolie such as SSZ-32 which has a small crvstaliite size-and a constraint index of 13 or greater, after calcination and in the hydrogen form. The catalyst possesses a silica to alumina rafio of greater than 20 and less thar 40.

U.S. Pal No. §,300,210 is also directed to hydrocarbon conversion processes employing 852-32. The 882-32 of U.S. Pat, No. 5,300,210 is. not jimited to a 10. small crystallite size.

U.S. Pat. No. 7,141,529 discloses a method of metakmadifving molecular sieves with different metals {a metal or metal selected from the group consisting of Ca, Cr. Mg, La, Ba, Pr, 8r, K and Nd and also with a Group Vill metal} to provide catalysts with improved isomerization selectivity using an nC feed. None of the processes produced a molecular sieve with @ small crystallite size. None of the isomenzation methods gave a slope of the Vi of the. product bofling at 850°F (343°C) and above versus the pour point of zero or less,

U.S. Pat. Publication No. 2007/6004 1898A1 discloses a method of making a small crystaiite MTT catalyst. Nothing (s disclosed of metal-modifving the molecular sieve,

SUMMARY OF THE INVENTION

There is provided a process for dewaxing a hydrocarbon feed to produce an isomerized product, the feed including straight chain and slightly branched paraffins having 10 or more carbon atoms, comprising contacting the feed under isomerization conditions in the presence of hydrogen with catalyst comprising a molecular sieve having MTT framework topology and having a crystallite diameter of about 200 to about 400 Angstroms in the longest direction, the catalyst containing at least one metal selected from the group consisting of Ca, Cr; Mg, La, Na, Pr, Sr, K and Nd and at least one Group VII metal.

There is also provided a dewaxing method, comprising isomerization dewaxing a hydrocarbon feed having at least 5 wi% wax over a catalyst to produce two of more isomerized products boiling at 343°C (850°F) or higher gach isomerized product having: a. a pour point between 0 and -30°C, and

WW bl a corresponding viscosity index of 85 or higher, wherein a fine fit to a chart of the pour points on an x:auxis and the viscosity indexes on a y-axis has 2 slope of the fine for y of zero or less.

There is aso provided a dewaxing process, comprising isomerization 16 dewaxing a hydrocarbon feed having at least 5 with wax over a catalyst to produce two or more isomerized products boiling at 343°C {850°F) or highest, each isomerized product having: #. & pour point between 0 and -30°C, and b. a corresponding viscosity index of 85 or higher, wherein a line fit to a chart of the pour points an an x-axis and the viscosity indexes ona y-axis has a slope of the line for y of zero or less; and wherein the yield of the two or more isomerized products boiling ai 343°C (B880°F} or higher 1s 80-wi% or greater based on the feed.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows yield versus pour point for isomerization of a heavy neutral (BOON) feed using a standard MT T~containing catalyst ("Std 852-32), a metal-modified standard MT T-containing catalyst ("'metal-modified 882-32") and the metal-modified, small crystallite MT T-containing catalyst “metai- modified SSZ-32X".

Figure 2 shows Viscosity index (VI) versus pour point for isomerization of a heavy neutral (SOON) feed using a standard MT T-containing catalyst ("std

S8Z-32"), a metal-modified standard MTT-containing catalyst ("metabmodified

S54-32") and the metal-modified, small crystallite MT T-containing catalyst ("metal-modified SSZ-32X".

Figure 8 shows gas make (production of C.-C. products) versus pour point tor isomerization of a heavy neutral {500N} feed using a standard

MTT-contatning catalyst ("std S8Z-32", a metal-modified standard

MTT-containing catalyst (“metal-modified S8Z-32") and the metal-modified, small crystallite MTT-containing cataiyst ("metal-modified $S2-32X").

Figure 4 shows yield of Us products versus pour point for isomerization of a heavy neutral (S00N) feed using a standard MTT-containing catalyst {st 852-32"), a metal-modified standard MTT-containing catalyst ("metal-modified 882.32") and the metal-moditied, small crystallite MTT -containing catalyst "metal-modified S8Z-32XM.

Figure § shows yield versus pour point for isomerization of a 150N feed using a standard MTT-containing catalyst (“std $82-32", a2 small crystallite

MTT-containing catalyst without metal loading ("small crystal SSZ-32). a metal-modifizd standard MTT containing catalyst {"metal-modified S8Z-32" and the metal-modified, small erystatlite MTT -containing catalyst "metal. modified 882-320".

Figure 8 shows Viscosity index (Vi versus pour point for isomerization of a

T30N feed using a standard MTT containing catalyst (“std S8Z-32", a metal modified standard MTT-containing catalyst "metal-modified SEZ-32" and the metal-modified, small crystallite MTT -containing catalyst {"metal-modifieg 3 88Z.32X.

Figure 7 shows gas make versus pour peint for isomerization of a 150 feed using a standard MTT-containing catalyst ("std $SZ-32"}, a metal-modified standard MT T-cortaining catalyst ("metal-modified SSZ-32" and the small crystallite MTT -containing catalyst ("metal-modified S52.32X". 5

Figure 8 shows yield of Light Naphtha (Cs -250°F) products versus pour point for isomerization of a 150N feed using a standard MT T-containing catalyst {"std 882-32"), a metalmadified 'standard MT T-containing catalyst ("meta modified 882-32") and the metal-madified, smal crystallite MTT-containing catalyst ("metal-modified §8Z.32X"),

Figure 8 shows yield versus pour point for isomerization of 2 Medium Neutral feed using a standard MT T-containing catalyst (“std 382-82"), a metal modified standard MT T-containing catalyst ("metal-modified S5Z-32" and the metai-modified, small crystallite MT T-containing catalyst ("metat-modified 85Z-32X7).

Figure 10 shows Viscosity index (V1) versus pour point for isomerization of a Medium Neutral feed using a standard MTT-containing catalyst ("std 882-32"), a metakmodified standard MTT -containing catalyst {"'metai- modified 552-32") and the metal-modified, small crystallite MT T:containing catalyst Cmetal-maodified 852-327).

Figure 11 shows a comparison of the X-ray diffraction patterns of 7 standard

MTT molecular sieve (“STANDARD 882-32" and a small crystaline MTT molecular sieve ("SSZ-32X7.

DETAILED DESCRIPTION OF EMBODIMENTS

In one embodiment the catalyst is comprised of & molecular sieve having the

MTT framework topology. The catalyst employed comprises from 5 to 85 wi% molecular sieve. "Molecular sieves! as used herein can include “zeolites”. The

BE terms "MTT type zeolite”, "MTT molecular sieve”. or variations thereot refers 10 the framework structure code for a family of molecuiar sieve materiale. The

Structure Commission of the international Zedlite Association {IZA) gives codes consisting of thres alphabetical letters to zeolites {a type of molecular sieve) having a structure that has been determined. Zeolites having the sams topology are generically calied by such thiee letters. The code MTT is given to the structure of molecular sieves including: Z8M-23, 882-32, BU-13, 181-4, and KZ-1. Thus, zeolites having a framework structure similar to that of ZSM- 23 and 882-32 are named a MT T-type zeolite. :

Other molecular sieves useful for isomerization dewaxing are intermediate pore size molecular sieves having a framework topology of MTT, TON, ABEL or

FER.

The small crystaliite MT T-type zeolites used in one embodiment of the catalyst have a crystallite diameter of about 200 Angstroms to about 400

Angstroms in the longest direction.

Catalyst Preparation in one embodiment, small crystallite MTT molecular sieves are prepared from an agueous solution containing sources of an alkali metal oxide or hydroxice, an alkylamine {such as jsobutylamineg), an organic carbon compound source of quaternary ammonium fon which is subsequently ton-exchangad fo the hydroxide form, an oxide of aluminum (e.g, wherein the aluminum oxide source provides aluminum oxide which is covalently dispersed on sical. and an oxide of sificen, In one embodiment the prganic carbon compound source of quaternary ammonium ion which is subsequently lon-exchanged to the hydroxide form is Nelowar atkyi-N'- isapropyl-imidazolium cation (for-example

CN, N'-diisopropyl-imidazolium cation or N-methy-N'-isopropyhimidazoiium cation). The aqueous solution has a composition in terms of mole ratios fathing within the following ranges:

Table 1 - Composition of mole ratios . Embodimem?i ~~ |Embodimentz

SiG IARD, TTT ess than do A088 TTT on mio; TTA TTT 020040 mm

SID; 0.05-0.50 | 0.10-0.28

WETso, oosoa0 60s

Ea TTT gee Bases TT wherein Q is the sum of QU, and Qu; Mis the alkali metal oxide or hydroxide, § and M+is the akalt metal cation derived from the alkali metal oxide or hydroxide. The alkali metals are the series of elements comprising Group 1 {IUPAC style) of the periodic tabla: lithium (LI), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium {Fr}.

Qqis an organic carbon compound source of guaternary ammonium on and

Cy isan amine. In one embodiment, Q, is an N-lower alikyi-N'-isopropyh imidazolium cation (for example an N, N-dilsopropyi-imidazolium cation or N- methyi-N'~ isopropyi-imidazolium cation. A number of different GQ, amines are useful. in one embodiment, isobutyl amine, neppentyl amine, monoethyl 1& amine, or mixtures thereof are suitable examples of GQ, The molar concentration of Qy is greater than the molar concentration of Q, Generally, the molar concentration of Q, ts in the range from 2 to about © times the molar congentration of Q,. U.8. Pat No. 5,785,847 {herein incorporated by reference) describes how a zeolite synthesis methed employing two organic sources of nitrogsn, one source being an amine containing from one to eight carbons provides significant cost savings over a method in-which the quaternary ammonium ion sowce {such as midazofium) is the only source of organic component. The combination of the two organic nitrogen sources allows the possibility of the primary template (used in smaller quantity) to nucleate the desired zedlite structure and then the amine to contribute © filling the pores in a stabilizing manner, during crystal growin. Empty pores of high silica zeolites are susceptible to re-dissolution under the synthesis conditions. The amine also can contribute to maintaining an elevated alkalinity for the synthesis, & in one embodiment, the organic carbon compound source of quaternary ammonium ion aiso providas hydroxide fon. in'one embodiment, the organic carbon compound source of quatemary 1 ammonium ion, G, of the aqueous solution is derived from a compound of the formula; 1% ~~, So

Foe KCH, &E hte Su

TH . wherein R is lower alkyl containing 1 to 5 carbon atoms, for example -CH3 or isopropyl. An anion (AS) which is not detrimental to the formation of the MTT molecular sieve is associated with the cation. Examples of an anion include halogens (e.g. fluoride, chioride, bromide and iodide), hydroxide, acetats, sulfate, carboxyigte, etc. Hydroxide is a particulary useful anion,

The reaction mixture is prepared using standard zeolitic preparation techniques. Typical sources of aluminum oxide for the reaction mixture include aluminates, alumina, and aluminum compounds, such as aluminum-coated silica colloids {one example is Nalco 1056 colloid sol),

A{80,.):, and other zeolites. in one embadiment the aluminum oxide is in a covalently dispersed form on sihoa. Aluminum oxide in a covalently dispersed form allows molecular sieve with increased aluminum content to be crystallized. increased aluminum content in the molecular sieve promotes isomerization. In another approach,

zeolites of pentasi! structure and lower silicalalumina ratios {approximately 10) can be used as aluminum oxide sources of feadstocks for the synthesis of smal crystallite MTT molecular sieve. These zeolites are recrystaliized to the small crystallite MTT molecular sieve in the presence of the organic sources

Q, and Q described above,

Mordenite and ferrierite zeolites constitute two such useful sources of aluminum oxide or feedstocks. These latter zeolites have also been used in the crystallization of ZSM- 5 and ZSM-11 (U8. Pat. No. 4,503,024).

Another approach, wherein the aluminum oxide is in a covalently dispersed form on silica, is to use an alumina coated silica sot such as that manufactured by Nalco Chem. Co. under the product name 1056 colloid $6 {26% silica, 4% alumina). In addition to providing nove! 887.32 YX with high aluminum content, use of the sol generates crystallites of less than 1C00A {along the principal axis) with surprisingly high isomerization capability.

In one embodiment, the catalytic performance of MTT molecular sieves in the hydrogen form) for cracking capability is manifested by Constraint index values (as defined in J. Catalysis 67, page 218) of 13 or greater and in one empodiment the MTT molecular sieve {in the hydrogen form) has a Constraint index from 13 to 22. Determination of Constraint index is alse disclosed in

U.S. Pal No. 4,481,177. In general, lowering the crystalifte size of a zeoliie leads to decreased shape selectivity. This has been demonstrated for ZSM-5 reactions involving aromatics as shown in J. Catalysis 99,327 (1986). in addition, zeolite ZSM-22, {U.5. Pat. No. 4,481,177) has been found t© be closely related to ZSM-23 (J, Chem, Soc. Chem. Comm. 1985 page THT Im the above reference on Z8M-22 it was shown thai ball-milling the crystallites produced a catalyst with a constraint index of 2.8. This is a surprisingly low value for this material given other studies which indicate that it is a very selective 10-ring pentasil (Proc. of Tth Intl. Zeolite Cont. Tokyo, 1688, page 23). Presumably the balimilling lsads tv & less selective but more active catalyst, by virtue of producing smaller crystallites. Unlike sarlier small crystallite catalysts with low constraint indexes, that smaller orystallite MTT molecular sieve ioaded with metals maintains high selectivity. § Typical sources of sificon oxide include silicates, silica hydrogel, silicic acid, colloidal silica, fumed silicas, tetraalkyl orthosificates, and silica hydroxides.

Salis, particularly alkali metal halides such as sodium chioride, can be added to or form in the reaction mixture. They are disclosed in the literature as aiding the crystallization of zeolites while preventing silica occlusion inthe lattice. 10

The reaction mixture is maintained ai an elevated temperature until the ‘crystals of the molecular sieve are formed. The temperatures during the hydrothermal crystallization step are typically maintained from about 140° C. to about 200° C.; for example from about 160° C. to about 180" C. or from 16 about 170° C. 10 aboui 180° C. The crystallization period is typically greater than t day, and in one embodiment the crysigliization period is from about 4 gays to about 10 days.

The hydrothermal crystallization is conducted under pressure and usually in an autoclave so that the reaction mixture is subject to autogenous pressure.

The reaction mifure can be slirred while components are added as well as during crystallization.

Once the molecular sieve crystals have formed, the solid product is separated from the reaction mixture by standard mechanical separation techniques such as filvation or centrifugation. The crystals are water-washed and then drag, e.g. at 80°.C. 1 180°C. for from 8 to 24 hours, to obtain the as-synthesized molecular sieve crystals. The drying step can be performed al atmospheric or subatmuospheric pressures.

Dunng the hydrothermal orystaliization step, the crystals can be slowed © nucleate spontaneously from the reaction mbdure. The reaction mixture san also be seeded with MTT crystals both to direct, and accelerate the crystallization, as well as to minimize the formation of undesired aluminosilicate contaminants. § In one embodiment, the: small crystallite MT Type zeolites used in the catalyst have a crystallite diameter of about 200 Angstroms to about 400

Angstroms in the longest direction. in one embodiment, the small crystallite MTT molecular sieve can be usad as- synthesized or can be thermally treated (calcined). The calcination is advantageously conducted at a temperature of about 750 F. Usually, itis desirable to remove the alkali metal cation by ion exchange and replace it with hydrogen, ammonium, or any desired metal ion. The molecular sieve can be leached with chelating agents, e.g, EDTA or dilute acid solutions, to increase 1& the silica alumina mole ratio. The molecular sieve can also be steamed.

Steaming helps stabilize the crystalline iathice to attack from acids.

The calcined molecular sieve is then loaded with at least one metal selected from the group consisting of Ca, Or, Mg, La, Na. Pr 81, K and Nd. These metals are known for their ability to modify performance of the catalyst by reducing the number of strong acid sifes on the catalyst and thereby lowering the selectivity for cracking versus isomerization. In one ernbodiment, modification also involves increased metal dispersion such that acid or cation sites in the catalysts are blocked. In one embodiment, metal loading is accompiished by a variety of techniques, including impregnation and ion exchange. Typically, the metal is loaded such that the catalyst contains 0.5 to & wi. % metal on a dry basiz. in one embodiment the catalyst contains 2 {0 4 wit metalon a dry basis.

Typical lon exchange technigues invoive contacting the extrudate or particle with a solution containing a salt of the desired replacing cation or cations.

Although a wide variety of salts can be employed, In one embodiment the salt of the desired replacing cation or cations is selected from the group of chlorides and other halides, nitrates, sulfates, and mixtures thereof,

Representative ion exchange techniques are disclosed ina wide varisty of patents including 3.8. Pat. Nos. 3,140,249; 3,140,251; and 3,140,253, each of which is incorporated herein by reference. ion exchange can take place either before or after the extrudate or particle is calcined. Calcination is carried out in a temperature range from 400 to 1100 °F.

Following contact with the salt solution of the desired replacing cation, the molecular sieve is dried at temperatures ranging from 148° F. to about 589° F.

The molecular sieve is then further loaded using a technique such as ; } impregnation with a Group Vill metal to enhance the hydrogenation function, in some embodiments it is desirable to coimpregnate a modifying metal and

Group VII metal af once, as disclosed in U.S. Pat No. 4.084 821. Inone 18 embodiment the Group Vill metal is platinum, paliadium or & mixture of the twa. in one embodiment, after metal loading, the material can be calgined in air or inert gas at temperatures from B00 to 800 °F.

Thus, an example of a typical method for preparing the catalyst involves the foliowing steps: {a) synthesizing the small crystalite MTT zeolite in an agueous solution: {b} mixing the small crystallite MTT zeolite with a refractory inorganic oxide carrier precursor and an agueous solution to form a mixture: (c) extruding or forming the mixture of step (b) to form an extrudate or formed particle; (d) drying the extrudate or formed particle of step (o); {) calcining the dried exirudate or formed particle of step (d);

{f) impregnating the calcined extrudate or formed particle of step (e) with at least one metal selected from the group consisting of Ca, Cr, Mg, La, Ba, Na,

Pr. Sr, K and Nd to prepare a metal-madified extrudate or formed particis; {g) drying the metal-modified extrudate or formed particle of step (fy; (h) further impragnating the metal-modified extrudate or formed particle of step (g) with a Group Vill metal to prepare a catalyst precursor, {iy drying the catalyst precursor of step (h); and {j) ceicining the dried catalyst precursor of stew (1) to form a finished, bound eatalyst

Use of an active material in conjunction with the synthetic molecular sieve,

Le. combined with it, tends to improve the conversion and selectivity of the catalyst in certain organic conversion processes. Examples of active materials are hydrogenating components and metals added to affect the overall functioning of the catalyst. in one embodiment the overall functioning of the catalyst includes enhancement of isomerization and reguction of ab cracking activity. tn one embodiment, small crystallite MTT molecular sieve can be used in intimate combination with hydrogenating components for those applications in which a hydrogenation-dehydrogenation function is desired. Typical hydrogenating components can include hydrogen, ammonium, metal cations, e.g. rare earth, Group HA and Group Vil metals, as well as their mixtures.

Examples of metal hydrogenating components include tungsten, vanadium,

molybdenum, rhenium, nickel, cobalt, chromium, manganese, platinum, palladium (or other noble metals). In one embodiment the Group Vil metal is a noble metal selected from the group of platinum, palladium, rhenium, and mixtures thereof. In another embodiment the Group Vil metal is a noble metal & selected from the group of platinum, palladium, and mixtures thereot, In one embodiment, the metal hydrogenating component is added such that it constitutes about 0.3 to about 5 wt.% of the catalyst on a dry basis.

Metals added to affect the overall functioning of the catalyst {including enhancement of isomerization and reduction of cracking activity) include magnesium. lanthanum (and other rare earth metals), barium, sodium, prasecdymium, strontium, potassium and neodymium. Other metals that might also be employed to affect the overall functioning of the catalyst include zing, cadmium, Btanium, aluminum. tin, and iron. :

Hydrogen, ammonium as well as metal companents can be exchanged into the molecular sieve. The zeolite can also be impregnated with the metals, or, the metals can be physically infimately admixed with the molecular sieve using standard methods known to the art. The metals can be ocoluded in the crystal lattice by having the desired metals present as ions in the reaction mixture from which the zeolite is prepared. in one embodiment, the molecular sieve zeolite described is converted fo its acidhe form and then is mixed with a refractory inorganic oxide carrier j precursor and an agusous solution to form a mixture. in one ambodiment, the agueous solution is-acidic. The agueous solution acts as a peptizing agent. in ‘one embodiment, the carrier {aise knows as a matrix or binder is chosen for being resistant to the temperatures and other conditions employed in organic conversion processes. Such matrix materials include active and inactive materials and syntheticor naturally occurring zeolites as well as inorganic materials such as clays, silica and metal oxides. in one embodiment the carrier occurs naturally. In another embodiment the carrier is in the form of gelatinous precipitates. sols, or gels, including mixtures of silica and metal oxides. in one embodiment the molecular sieve is composited with porous matrix § materials and mixtures of matrix materials such as silica, alumina. titania, magnesia, silica-alumina, silica- magnesia, silica-zirconia, silica-thoria, silica- beryliia, silica- titania, titania-zirconia as well as ternary compositions such as sflica~ alumina-thoria, silica~alumina-zirsonia, silica-alumina-magnesia and silica-magnesia-zirconia. The matrix can be in the form of a cogel. in one embodiment. the matrix materials are alumina and silica.

Inactive materials can suitably serve as diluents to control the amount of conversion in a given process so that products can be obtained economically without using other means for controlling the rate of reaction. Frequently, zeolite materials have been incorporated into naturally cocurring clays, e.g., bentonite and kaolin. These materials e.g. clays, oxides, etc, function, in part, as binders for the catalyst. It is desirable to provide & catalyst having good crush strength, because in petroleum refining the catalyst is often subrjectad 10 rough handling. This tends to break the catalyst down into powders which cause problems in processing. “Metal-modified” in this. disclosure means that the catalyst molecular sieve contains at least one metal selected from the group consisting of Ca, Cr, Mg,

La, Na, Pr, 5 K and Nd, and at least one Group VI metal, Group Vili metals are Fe, Co, NI, Ru, Rh. Pd, Og, Ir, and PL in one embodiment, naturally occurring clays are composited with the synthetic small crystallite MTT molecular sieve. Examples of naturally aceurring clays incliide the montmorilionite and kaolin families, which families include the sub-bentonites and the kaolins commonly known as Dixie,

McNamee, Georgia and Florida clays or others in which the main mineral constituent is halioysite, kaolinite, dickite, nacrite, or anauxite. Fibrous clays such as sepiolite and altapulgite can also be used as suppons. Such clays can be used in the raw state as originally mined or can be initially subjected fo calcination, acid treatment or chemical madification. & The mixture of molecular sieve and binder can be formed into a wide variety of physical shapes. Generally speaking, the mixture can be inthe form of a powder. a granule, or a molded product, such as an extrudate having a particle size sufficient to pass through a 2.5-mesh {Tyler screen and be retained on a 48-mash (Tyler) screen. In cases where the catalyst is molded, such as by extrusion with an organic binder, the mixture can be extruded before drying, or dried or partially dried and then extruded. Small crystallite

MTT molecutar sieve can also be steamed. Steaming helps stabilize the crystalline lattice {o attack from acids. The dried extrudate is then thermally treated, using calcination procedures.

Generally i is desirable to minimize tha amount of molecular sieve in the finished catalyst for economic reasons. Lower levels of the molecular sieve in the finished catalyst are desirable if good activity and selectivity results are achieved. In ong embodiment, the level of molecular sieve is between 5 and

Bb wt %. or in another embodiment between § and 80 wi%. The level of molecular sieve is varied for different molecular sieve types. in one embodiment, the metal-modified small crystallite MTT catalyst gives superior vields and exceptional Viscosity index (V1 on a variety of feeds. The byproduct selectivity is significantly changed compared to catalysts containing standard MT T-type zeolite. e.g, the catalyst results invery low gas and naphtha make, For example, on a waxy S00N hydrocrackate feed containing 21% wax, with a'waxy Vi of 122, the product yield was 87% at a pour point of 18 C anda Vi of 120 - 121. Typically. a much larger drop is seen from waxy

Viiodewsxed Vi For example, when a catalyst containing a standard MTT- type zeolite was employed. the resultant product Vi was about 111. A metal modified standard MT T-type zeolite catalyst gave 8 Vi of 115. Gas make and naphtha make were both much reduced by the use of the small crystallite

MTT molecular sieve loaded with metals. Such a high vield and product WV} very close to the waxy feed Vl after dewaxing was very surprising. The yield of 700 F+ dewaxed. lube product in this instance was as high as 97%. Also, the slope of the product Vi versus pour point is unusual in that it was not lowered at ower pour point.

Data was aiso obtained on a 150N waxy hydrocrackate which also showed improved product yield and Vi compared to previous MTT-type catalysts.

Again, lower gas make and naphtha make was observed. An MN feed was also tested and improved yield and Vi were again observed.

When a Fischer-Tropsch wax feed was treated using the catalyst comprising a small crystallite MTT Molecular sieve loaded with metals the resultant 850 18 F+ product had exceptional V's of 185-170 at pour points between -25 and - 30 °C, Wher the 750 °F+ bofling product was further split into two fractions, the 750-880 °F fraction had a kinematic viscosity at 100 °C of 3.5 mms ang a very high Vi of 151 at a pour point of ~18°C, and the 850 "F+ fraction had s viscosity of 8. 7Tmmis. a pour point of “11° and a Vi of 168. Kinemaiic viscosity was measured by ASTM D445-08, pour point was measured by

ASTM DEB50-02, and Vi was measured by ASTM DI270-04,

Feeds in one embodiment, the process using the catalyst comprising a molecuiar sieve having a small crystallite MTT topology and loaded with matals is used to dewax a variety of feedstocks ranging from relatively light distillate fractions such as kerosene and jet fuel up to high boliing stocks such as whole crude petroleum, reduced crudes, vacuum tower residua, Sycle oils, synthetic crudes (e.g, shale oils, tars and oll, etc.), gas oils, vacuum gas oils, fools oils,

Fischer-Tropsch derived waxes and intermediate products, slack waxes, deoiled slack waxes, waxy lubricant raffinates, n-paraffin waxes, NAD waxes,

waxes proguced in chemical plant processes, deoiled petroleum derived waxes, microcrystalline waxes, other heavy oils, and mixtures thereof. in one embodiment the feedstock is a hydrocarbon having a weight percent & wax of atieast 8 %.

Weight percent wax inthe feed is measured by heating the waxy sample unt it is just above its. pour point, pouring 100 grams of the heated waxy. sample into a tared 1 liter beaker and recording the weight of the heated waxy sample fo two decimal places: adding 400 mb of a 1:1 mixture of toluena:methyl ethyl ketones (MEK) to the beaker and dissolving the waxy sample with gentle stirring over a hot plate until homogeneous. Cover the beaker with a piece of aluminum foil and place it in the freezer which has been preset to the pour point temperature of the feed. Allow the sample to sit undisturbed ovarrHght.

After cooling in the freezer overnight, filter the mixture using a filter assembly instatied in the freezer. Use No. 4 Whatman filter paper (18.5 em in diamster) ina Buchner funnel and cover the funnel with a piece of aluminum foil to keep ice crystals from collecting in the funnel. Perform the filtration by connecting the funnel to heavy-duty vacuum, prewetting the filter paper with cold MEK, pulling the vacuum, quantitatively transfering the entire mixture in the beaker into the funnel using a spatula, rinsing the beaker with cold MEK, and filtering the rinsate. Close the freezer and wail until the solvent has compietely drained through the filter, and the freezer has dropped to its original preset temperature, Wash the wax filter cake thoroughly using cold MEK. Allow the wax cake to dry, disconnect the vacuum, and remove the filterfunne assembly from the freezer. Using a spatula, transfer as much wax as possible from the filter to a tared jar, Remove the last traces of filtered wa with hot toluene and transfer the rinsate to the tered jar. Evaporate off the toluene and weigh the wax that was collected in the tared jar. Pourthe oil filtrate indo atared flask. Strip off the solvent using a rotary evaporator and weigh the flask plus remaining olf and determine the oll weight. The percent wax is the weight of the wax that was collected in the tared jar divided by ths weight of the heated waxy sample, multiplied by 100.

Straight chain n-parafiins either aione or with only slightly branched chain parafiing having 16 or more carbon atoms are sometimes referred to herein as waxes. The feedstock will often baa C10+ feedstock generally bailing anove about 380°F, since lighter ols will usually be free of significant guantities of waxy components. However, the process is particularly useful with waxy distillate stocks such as middie distillate stocks including gas oils, kerosenes, and jet fuels, lubricating oil stocks, heating ails and other distillate fractions whose pour point and viscosity need fo be maintained within certain specification limits. Lubricating oil stocks will generally boll above 230°C. {450°F.}), more usually above 315°C. {800°F ). Hydroprocessed stocks are a convenient source of stocks of this kind and also of other distiliate fractions 156 since they nermally contain significant amounts of waxy n- paraffins. The feedstock of the present process will normally be a C10 + feedstock comaining paraffins, olefins, naphthenss, aromatic and heterocyclic compounds and with a substantial proportion of higher molecular weight n- paraffins and slightly branched paraffins which contribute to the waxy nature of the feedstock, During the processing, the n-paraffine and the slightly branched paraffins undergo some cracking or hydrocracking to form liquid range materials which contribute to a low viscosity product, The degree of cracking which occurs is, howsver, mitad so that the vield of products having boiling points below that of the feedstock is reduced, thereby preserving the 2% sconomic value of the feedstock,

Typical feedstocks include hydrotreated or hydrocracked gas oils, hydrotreated lube off raffinates. bright stocks lubricating olf stocks, synthetic ails, foots oils, Fischer-Tropsch synthesis oils, high pour point polyolefins, normal alphaoiefin waxes, slack waxes, deciled waxes, microcrystalline waxes, and mixiures thereof,

Fischer-Tropsch waxes can be obtained by well-known processes such as, for example, the commercial SASOL® Slurry Phase Fischer-Tropsch technology, the commercial SHELL® Middle Distillate Synthesis (SMDS) Process, or by the non-commercial EXXON® Advanced Gas Conversion {AGC-21) process. § Details of these processes and others are described in, for example, EP-A- 778958, EF-A-868342; U.S. Patent Nos. 4,943 872, 5,058,299, §,733,8308, and RE3G073 ; and US Published Application No. 2005/02278668, WO-A- 2634817. WO-A-8820720 and WO-A-05107835. The Fischer-Tropsch synthesis product usually comprises hydrocarbons having 7 to 100. or sven more than 100 carbon atoms, and typically includes paraffins, olefins and oxygenated products. Fischer Tropsch is a viable process to generate clean altermative hydrocarbon products, including Fischer-Tropsch waxes.

Conditions 18

The conditions under which the isomerization dewaxing procass is carried out generally include a temperature which falls within a range from about 382°F io about 8B0°F, and a pressure from about 15 to about 3000 psig. Typically, the pressure is from about 100 to about 2500 psig. The liquid hourly space welocity during contacting is generally from about U.1 to about 20, for gxampie from about 0.1 to about 5. In one embodiment the contacting is carried out in the presence of hydrogen. The hydrogen to hydrocarbon ratio can fall within a range from about 2000 to about 10,000 standard cubic fest Ha per barrel oo hydrocarbon, for example from about 2500 to about 5000 standard cubic feet

Hp per bare! hydrocarbon, tn one embodiment the isomerization dewaxing product is further treated for example by hydrofinishing or adsorbent treatment. The hydrofinishing can be conventionally carried out in the presence of a metallic hydrogenation catalyst. for example, platinum on alumina. The hydrofinishing can be carried out at a temperature of from about 374°F to about 644°F and a pressure of fram about 400 psig to about 3000 psig. Hydrofinishing in this manner is described in, for example, U.S. Pat. 3,852.207 which is incorporated herein by reference.

EXAMPLES

8

Another term that may be used to describe the small crystallite MTT molecular sigve loaded with metals is “broadiine.” The synthesis of a broadiine {in reference to the x-ray diffraction pattern) small crystallite molecular sisve is really synonymous with crystallizing a very small crystal example of the zeolite. The x-ray diffraction pattern broadens as the crystallites are reduced ivsize. In general, for the system of MTT molecular sieves, as the S0./ALO, ratio diminishes (greater wi% Al in the zeolite product) the crystallite size also diminishes,

Table 2(a) shows the peak listing and refative intensity of peaks of standard 882-32. a standard MTT molecular sieve. Table 2(b} shows the peak listing and relative intensity of peaks of smali crystallite MTT moigcular sieve prior to metal loading. Table 2(b) magnifies peak width so that major peaks of small crystallite MTT molecular sieve and standard S82-32 are easily compared.

Table 2{a) ~ Peak listing of standard 882.32 2Theta d-spacing | Relative Intensity (%) (A) | (io) x 106 7.8 | 11.2 18

CTT TTT

TTT TTT

214 4.15 TTT TTT

Twn TEE TTT wT

TEs EERE TTY

TE EETTTTTT gg rt

TREAT TTT

Table 2{b} ~ Peaks in as-made Small crystallite MTT Molecular Sieve

ZThem | dspaming Relative {AS intensity (%} pnoxi0m

TTTREETTTTTTTRG TE TTT

TEER TTT

TEES Tass ETT 20.81 4.27 | 31 :

508 TTT BETTER [mw TERETE ae EE TE ~

TTR TTR ETT

TEE

Figure 11 shows the X-ray diffraction patterns of these two types of MTT molecular sieves, and demonstrates clearly the broader x-ray diffraction peaks of the small crystallite MTT molecular sieve,

EXAMPLE 1 SYNTHESIS OF SMALL CRYSTALLITE MTT MOLECULAR

SIEVE

Small crystallite MTT molecular sieve was synthesized as follows: A Hastalloy

Ciinerfor a 5 galion autoclave unit was used for the mixing of reagents and then i the subsequent thermal treatment. At a rate of 1500 RPM and for a period of ¥4 hour, the following components were mixed once they had been added in the order of description. 300 grams of a1 Molar solution of NN

Diisopropy! imidazolium hydroxide was mixad into 4500 grams of water. The saltiodide was prepared as in US 4, 483.835, Exampie §, and then subsequently was ion-exchanged to the hydroxide form using BioRad AG1-X8 sxchange resin. 2400 grams of 1 N KOH were added, 1524 grams of Ludox

AB-30 (30wt% 8:0; were added. 1080 grams of Naico's 1056 colloid sol (26wt% SO; and 4 wWi% AJGs) were added. Last, 181 grams of isobutylamine 13 were stirred into the mixture. The molar concentration of the amine Qu excesded the molar concentration of the mmidazoiium compound

Once the stirring was finished the autoclave head was closed up and the : reaction was taken up to 170°C with an 8 hour ramp up time. The system was stirred at 180 RPM. The reaction was terminated so that a product was colected after 106 hours of heating. The solids were collected by filtration {which goes very slowly; an indication of small crystals). The solids were subsequently washed several times and then dried. The dried material was analyzed by x-ray diffraction and the pattern is shown in Table 3A comparison is made with the more standard 82-32 data presented in Table :

Z{a) and it car be seen that the new product of Example 1 is related fo 8582: 32 but has the x-ray diffraction lines considerably brogdensd.

Table 3 26 | dspacing | Intensity | Relatve

TENT VR | Intensity (%}

Wox100)

TER wes wm

TET 77

TRAE TE TTT TTT srs se: 3 8 I 18.53 4.54% 41 i 7 (m5 44% Gsnouds | i0shouier

CF az an TTUTRWMTTT

IE EC I

2457 3823 30 52

TEER Sam TE

CTE TERETE TTT TTT

Tm swe wT

In a concen that the product might be 2 mix of small crystals and considerabie amorphous material, a TEM {Transmission Electron Microscopy) analysis was carried oul. The microscopy work demonstrated that the product of Example 1 was guite uniformly small crystals of MTT molecular sieve with very little evidence of amorphous material. The crystaliites were characterized by a spraad of small, broad tathe-iike components having & diameter in the range of about 200 to about 400 Angstroms in the longest direction. The

SHOALD: ratio of this product was 26.

EXAMPLE 2

The product of Example 1 was calcined to 1100°F in air with a ramp of 1 deg.

C/min(1.8F/min) and plateaus of 280°F for 3 hours, 1000 F for 3 hours and then 1100°F for 3 hours. The calcined material retained its x-ray crystallinity.

The calcined zeolite was subjected to 2 ion-exchanges at 200°F {using NH.

NO4) as has been previously described in US Pat. No. 5.282 827. The lon. exchanged material was recaicined and then the microporasity measurements were explored, using a test procedure also described in 5,252,527 The naw product. small crystallite MTT molecular sieve, had some unexpectad differences va. conventional SS7-32.

The Ar adsorption ratio for small crystallite MTT molecular sisve {Ar adsorption gt 87K between the relative pressures of 0.001 and 0.1) (otal Ar adsorption up to relative pressure of 0.1) is largerthan 0.5. inone embodiment the Ar adsorption ratio is in the range of 0.58 to 0.70. In contrast for the conventional 882-32, the Ar adsorption ratio is less than 0.5, typically between 0.35 and 0.45. The small crystallite MTT molecular sieve of

Examples 1 and 2 demonstrated an Argon absorption ratio of 0.82.

The external surface area of the crystaliites jumped from about SU még {882 32) 10 150 {smal crystaliite MTT molscular sieve) mg, indicating the considerable external surface as a result of very small crystals. Al the same 28 time, the micropore volume for small crystallite MTT molecular sieve had dropped to about 0.035 coigm, as compared with about 0.08 coigm for standard 887.32.

EXAMPLE 3

Small crystatite WITT zeolite was composited with aluming, extruded, dried, and calcined. The dried and calcined extrudate was impregnated with a solution containing both platinum and magnesium | and then finally dried and calcined, The overall platinum loading was 0.325 wi. %. This metai-modifisd catalyst was then tested for isomerization on a waxy 500N hydrocrackate feed having 21% wax, a kinematic viscosity at 100°C of 10.218 miss, and a poLy § pointof +51°C. isomerization process conditions used were 5 LHSV of 1.0 hr ', 4000 sciibhi gas to oil ratio. and a total pressure of 2300 psig. Following isomerization the products were hydrofinished over a PUPS silica alumina hydrofinishing catalyst at 450 °F. The Vi of the waxy S00N hydrocrackats feed was 122, and the VI of the solvent dewaxed waxy 500 hydrocrackate feed was 106 when solvent dewaxed at -18°C. The difference between the waxy

Vi and the catalytic isomerized product Vi was only two (122-120), which was exceptional.

Figures 1 and 2 show the vield and product Vi versus pour point achieved with the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst ("'metab-modified 88Z-32X"). The data at different product pour points, and corresponding viscosity indexes. was generated by changing the operating temperature of the dewaxing catalyst (for example, a lower pour point is achieved by raising the catalyst temperature). The results are compared with two other catalysts, a standard MTT-containing catalyst (Std 882-32) and a metal-modified standard MTT -containing catalyst metal modified 852-327}, tested under the same conditions and using the same feed. The isomerization yield of product boiling at 700°F and above using the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst at the typical product target range of -12 to -15°C pour point was an unprecedented 96 to 97%. The product Vi was approximately 120, which is also excelent, and is believed to be attributable to the sxceplional amount of isomerized wax retained in the base oil boiling range product. The siope of the V1 of the product boiling at 700°F and above versus the pour paint was negative, approximately -0. 18, such that the Vi was actually increassd as the pour point was reduced. Example 3 demonstrates where two or more isomerized products boiling at 343°C (850°F) or higher have a corresponding viscosity index af 104, 110, or higher. Figures 3 and 4 show the low yields of

Cr to Ci products ("Gas-make”) and Cs 10 © 2s product (Naphtha) achieved with the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst ("metal-modified 88Z-32X"), compared with two other catalysis,

EXAMPLE 4

The same metabmodified catalyst from Example 3 was also tested for isomerization on a waxy 150N hydrocrackate feed containing 10% wax and a pour point of +32°C. isomerization process conditions used were a LHSV of 1.0 he’, 4000 scfibbl gas to oll ratio, and a total pressure of 2300 psig.

Following isomerization the products were hydrofinished over a PUP siica alumina hydrofinishing catalyst at 450 °F

Figures 5.and 8 show the yield and product VI versus pour point achieved with the metai-modified catalyst comprising the small crystallite MTT zeolite cataiyst {("metal-modified SSZ-32X"). The results are compared with three other catalysis: a standard MTT containing catalyst (“Std 88232), a metal modified standard MTT-containing catalyst ("metal-modified $82-327), and a standard small crystallite MTT zeolite catalyst that was not metal-modified ("smal crystal SSZ-32X7). All four catalysts were tested under the same conditions and using the same 150N feed. The isomerization yield of product boiling at 850°F and above using the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst at the typical product target range of -12 10 15°C pour point was 84 to 85%. The product Vi was approximately 108.

The slope of the Vi of the praduct bofling at 850°F and above versus the DOUr point was approximately 0.08. which was significantly fess than that obtained with the comparison catalysts. The VV! was not lowered as much as the psy point was reduced with the metal-modified catalyst comprising the small orystallite MTT zeolite catalyst, Figures 7 and & show the iow yields of Cy to

Ce products (“Gas-make”) and Og 10 C as product (Naphtha) achieves with the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst ("metal-modified SSZ-32X"). compared with two other catalysts.

EXAMPLE 5

The same metalmodified catalyst from Example 3 was also tested for isomerization on a waxy medium neutral (220N, MN) feed containing 12.2% wax, a kinematic viscosity. at100°C of 8.148 mm%s. and a pour point of +36°C. isomerization process conditions used were a LHSV of 1.8 nr, 4000 sclibbl gas to oil ratio, and a total pressure of 2300 08ig. Following isomerization the products were hydrofinished over a PUP silica aluming hydrofinishing catalyst at 450 °F,

Figures 8 and 10 show the yield and product Vi versus pour point achieved with the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst (“metal-modified SSZ-32X". The results are compares with two other catalysts: a standard MT T-containing catalyst ("standard 882-32), and a metal-madified standard MTT-containing catalyst "metal-modified SSZ-327

All three catalysts were tested under the same conditions and using the same 220N eed. The isomerization yield of product boiling at 850°F and above using the metakmodified catalyst comprising the small crystallite MTT zeolite catalyst at the typical product target range of -15°C pour point was about 82%. The product Viwas 105. The slope of the Vi of the product boiling at

B50°F and above versus the pour point over a range of pour points from -12°0 10 “22°C was essentially zero, which again was significantly less than that obtained with the comparison catalysts. The Vi was not lowered as the Bour point was reduced with the metal-modified catalyst comprising the small crystallite MTT zeolite catalyst.

EXAMPLE 6

The same metatmodified catalyst from Example 3 was tested for isemerization on a hydrotreated Fischer-Tropsch wax feed having more than 90% wax made by the SASOL® Surry Phase Fischer-Tropsch process. isomerization process conditions used were a LHSV of 1.0 htt, 5000 scffbht gas to oil ratio, and a total pressure of 300 psig. Following isomerization the products were hydrofinished over a PUPA silica alumina hydrofinishing catalyst at 450 °F. The resultant products boiling at 850°F and ahove had Vis of 185 to 170 at pow points between -25 and -30°C. The yield of products boiling at 650°F and above were greater than 85 wi % at & pour point of - 20°C. The products boiling at 850°F and above were further split by vacuum distillation into two fractions, one boiling between 750 to 850°F and the other boiling at 850°F and higher. The lighter boiling fraction had a kinematic viscosity at 100°C of 3.8 mms, a VI of 151, and a pour point of -18 °C. The heavier boiling fraction had a kinematic viscosity at 100°C of 8.7 mms, a Wi 18 of 188, and a pour point of ~11°C. A COmMPanson run using a metal-modified standard MT T-containing catalyst under the same process conditions and on the same feed gave lower yields but stightly higher Vis, Interestingly, even though the Vis were slightly lower using the metal-modified small crystallite

MTT zeolite catalyst the slope of the Vi of the product boiling at 850°F and above versus the pour point over a range of pour points from -20°C io -50°C was significantly less, less than 0.58 than the slope obtained with the comparison catalyst, greater than 0.72.

Claims

WHAT IS CLAIMED 1S:

1. A process for dewaxing a hydrocarbon feed to produce an isomerized product, the feed inciuding straight chain and slightly branched paraffins having 10 or more carbon atoms, comprising contacting the feed under isomerization conditions in the presence of hydrogen with a catalyst comprising a molecular sieve having MTT framework topology and having a crystallite diameter of about 200 fo about 400 Angstroms in the fongest direction, the catalyst containing at least one metal selected from the group consisting of Ca, Cr. Mg, La, Na, Pr, 8r, K and Nd and at east one Group VI metal.

2. The process of claim 1 wherein the MTT molecular sieve is selected from the group consisting of S82:32, Z5M-253, EU-13, 181-4, and KZ-1.

3. The process of claim 1, wherein said feed is selected from the group consisting of hydrotreated or hydrocracked gas oils, hydrotreated lube oii raffinates, bright stocks, lubricating oil stocks, synthetic oils, foots oils, Fischer-Tropsch synthesis oils. high pour point polyolefins, normal alphaotefin waxes, stack waxes, deoiled waxes rmicrocrystaliine waxes, and mixtures thereof. 4, The process of claim 1. wherein Group VII metals are selected fram the group consisting of platinum and palladium, and mixtures thereof,

&. The process of claim 1 wherein said contacting is carried out at 5 temperature of from 232 — 427 °C {450 - BOOSF), and a pressure inthe range from about 103.4 kPa gauge (15 psig) to about 20.885 kPa gauge (3000 psig).

8. The process of claim 5 wherein sald pressure is in the range from about 688.5 kPa gauge {100 psig) to about 17237 kPa gauge (2500 psig). - & 7 The process of claim 5, wherein the liquid hourly space velocity during contacting is from about 0.4 to about 20.

8. The process of claim 7, wherein the liquid hourly space velocity is from

0.5 to about 5. 8 The process of claim 1 wherein the hydrocarbon feed is hydrotreated prior to isomerization at a temperatures in the range from 163 to 427 “0 (325.10 BOO° 7), 18 10. The process of claim 1, further comprising a hydrofinishing step following isomerization.

1. The process of claim 10 wherein hydrofinishing is camied out at a temperature in the range from about 163 to about 210 °C {325 to about &909 F} and a pressure in the range from about 2068 kPa gauge (30C psig) to about 20,685 kPa gauge {3000 psig).

12. The process of claim 1 further comprising hydrofinishing of isomenzed product.

13. A dewaxing method, comprising isomerization dewaxing a hydrocarbon feed having at least 8 wi% wax over a catalyst to produce two ar more isomerized products bolling at 343°C {830°F) or higher, each isomerized product having:

a. & pour point between ( and -30°C, and bh a corresponding viscosity index of 85 or higher,

wherein a line fit to a chart of the pour points on an x-axis and the viscosity indexes on a y-axis has a slope of the ine for y of zero of less.

14. The dewaxing method of claim 13. wherein the hydrocarbon feed has at oo . 5 sas? 10 wi% wax.

18. The dewaxing method of claim 13, wherein the hydrocarbon feed has a kinematic viscosity at 100°C of 2.5 mm¥s or greater,

18. The dewaxing method of claim 13, wherein the catalyst comprises a malecular sieve having MTT framework topology and having a crystallite diameter of about 200 to about 400 Angstroms ir the longest direction, 18 17. The dewaxing method of claim 18, wherein the catalyst further comprises at least one metal selected fron the. group. consisting of Ca, Cr, Mg, La, Na, Pr; St, K and Nd.

18. The dewaxing method of claim 17, wherein the catalyst further comprises at least one Group Vili metal.

18. The dewaxing method of clair 12, wherein the two or more isomerized products boiling at 343°C (850°F) of higher have a corresponding viscosity index of 104 or higher,

20. The dewaxing method of claim 13, wherein a yield of the two or mors isomerized products boiling at 343°C (B50°F) or higher is 80 wt% or greater based on the feed.

21. The dewaxing method of claim 20. wherein the yield ts 94 wi%s or greater.

22. The dewaxing method of claim 13. wherein the slope of the line is less than -0.08,

23. A dewaxing process, comprising isomerization dewaxing a hydrocarbon feed having at least 5 wi% wax over a catalyst to produce two or more isomerized products boiling at 343°C (B850°F) or higher. each isomerized product-having:

8. a pour point between 0 and 30°C, and b a corresponding viscosity index of 95 or higher: wheremn a line fit to a chart of the pour points on an x-axis and the viscosity indexes on a y-axis has a slope of the line for v of zero or less: and wherein the yield of the two or more isomerized products bailing at 343°C {(850°F) or higher is 80 wt% or greater based on the feed. 16 24. The dewaxing process of claim 23, wherein the molecular sieve has MTT framework topology.

25. The dewaxing process of claim 23, wherein the molecular sieve has crystallite size of about 200-400 Angstroms,