WO1991012299A1 - A catalytic hydrocracking process - Google Patents

Abstract

A hydrocracking process comprises the step of contacting a hydrocarbon stream under hydrocracking conditions and in the presence of hydrogen with a hydrocracking catalyst composition comprising a synthetic porous crystalline zeolite having an X-ray diffraction pattern including the following lines:

Description

A CATALYTIC HYDROCRACKING PROCESS

This invention relates to a catalytic hydrocrackiiig process for upgrading hydrocarbon streams.

Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure as determined by X-ray

diffraction, within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolitic material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have came to be known as "molecular sieves" and are utilized in a variety of ways to take advantage of these properties. Such molecular sieves, both natural and synthetic, include a wide variety of positive ion-containing crystalline silicates. These silicates can be described as a rigid

three-dimensional framework of SiO₄ and Periodic Table Group IIIA element oxide, e.g., AlO₄, in which the tetrahedra are

cross-linked by the sharing of oxygen atcaris whereby the ratio of the total Group IIIA element, e.g., aluminum, and silicon atoms to oxygen atoms is 1:2. The electrovalence of the tetrahedra containing the Group IIIA element, e.g., aluminum, is balanced by the inclusion in the crystal of a cation, e.g., an alkali metal or an alkaline earth metal cation. This can be expressed wherein the ratio of the Group IIA element, e.g., aluminum, to the number of various cations, such as Ca/2, Sr/2, Na, K or Li, is equal to unity. One type of cation may be exchanged either entirely or partially with mother type of cation utilizing ion exchange techniques in a conventional manner. By means of such cation exchange, it has been possible to vary the properties of a given silicate by suitable selection of the cation.

Prior art techniques have resulted in the formation of a great variety of synthetic zeolites. Many of these zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite Z (U.S. Patent No. 2,882,243), zeolite X (U.S. Patent No. 2,882,244), zeolite Y (U.S. Patent No.

3,130,007), zeolite ZK-5 (U.S. Patent No. 3,247,195), zeolite ZK-4 (U.S. Patent No. 3,314,752), zeolite ZSM-5 (U.S. Patent No. 3,702,886), zeolite ZSM-11 (U.S. Patent No. 3,709,979), zeolite ZSM-12 (U.S. Patent No. 3,832,449), zeolite ZSM-20 (U.S. Patent No. 3,972,983), zeolite ZSM-35 (U.S. Patent No. 4,016,245), and zeolite ZSM-23 (U.S. Patent No. 4,076,842).

The hydrocxacking of hydrocarbons to produce lower boiling hydrocarbons, and in particular, hydrocarbons boiling in the motor fuel range, is an operation upon which a vast amount of time and effort has been spent in view of its commercial significance. Hydrocxacking catalysts usually comprise a hydrogerataon-dehydrogenation component deposited on an acidic support such as silica-alumina, silica-magnesia, silica- zirconia, alumina, acid treated clays and zeolites.

Zeolites have been found to be particularly effective in the catalytic hydrocracking of a gas oil to produce motor fuels and such has been described in many U.S. patents including Nos. 3,140,249; 3,140,251; 3,140,252; 3,140,253; and, 3,271,418.

A catalytic hydrocracking process utilizing a catalyst comprising a zeolite dispersed in a matrix of other components such as nickel, tungsten and silica-alumina is described in U.S. Patent No. 3,617,498.

A hydrocracking catalyst comprising a zeolite and a hydrogenation-dehydrogenation component such as nickel-tungsten- sulfide is disclosed in U.S. Patent No. 4,001,106.

The hydrocracking process described in U.S. Patent No. 3,758,402 utilizes a catalyst possessing a large pore size zeolite component such as zeolite X or Y and an intermediate pore size zeolite component such as ZSM-5 with a hydrogenation- dehydrogenation component such as nickel-tungsten being

associated with at least one of the zeolites.

Hydrocarbon conversion utilizing a catalyst comprising a zeolite, such as ZSM-5, having a zeolite particle diameter in the range of 0.005 micron to 0.1 micron and in some instances containing a hydrogenation-dehydrogenation component is disclosed in U.S. Patent No. 3,926,782.

The hydrocracking of lube oil stocks employing a catalyst comprising a hydrogenation component and a zeolite such as ZSM-5 is disclosed in U.S. Patent No. 3,755,145.

Hydrocracking operations featuring the use of dual reaction stages, or zones, and/or two different catalysts are also kncwn.

For example, U.S. Patent No. 3,535,225 discloses a dual-catalyst hydrocracking process in which a hydrocarbon feedstock: is initially contacted with a first catalyst comprising a hydrogenation component and a component selected from the group consisting of alumina and silica-alumina and subsequently with a second catalyst provided as a silica-based gel, a hydrogenation component and a zeolite in the amiiraiium or hydrogen form and free of any loading metal or metals.

U.S. Patent No. 3,788,974 discloses a two-catalyst hydrocracking process wherein a hydrocarbon oil feedstock containing from 0.01 to 0.5 wt.% nitrogen compounds is contacted in a first hydrocracking zone with a zeolite catalyst of the faujasite type in combination with a nictel/tungsten

hydrogenation component to provide an effluent which is contacted in a second separate hydrocracking zone with a hydrocracking catalyst, preferably zeolite X or Y.

Catalytic hydrocracking of a hydrocarbon feedstock can in certain cases be accαrpanied by dewaxing, that is selective conversion of stxaight-chain and slightly branched chain paraffins, such that the pour point of the product is reduced.

Thus, U.S. Patent No. 4,486,296 teaches hydrowaxing and hydrocaracking of a hydrocarbon feedstock over a three-component catalyst comprising zeolite beta.

In accordance with the present invention, there is provided a hydrocracking process which comprises contacting a hydrocarbon stream under hydrocracking conditions and in the presence of hydrogen with a hydrocracking catalyst composition comprising a synthetic porous crystalline zeolite having, in its calcined form, an X-ray diffraction pattern with lines set forth in Table I, infra.

The term "hydrocracking" should be understood herein to refer to any hydroconversion operation in which a relatively heavy hydrocarbon undergoes clacking to hydrocarbon products of lower molecular weight.

The present process is especially advantageous for hydrocracddng heavier waxy fractions, e.g., those having boiling points of 343°C (650°F) or higher, e.g., light virgin gas oils, light catalytic cycle oils and light vacuum gas oils, and their mixtures. The present process enables such heavy feedstocks to be converted to distillate range products boiling below 343°C (650°F) but in contrast to prior processes which use large pore catalysts such as zeolite Y, the consumption of hydrogen is less and, for a given rate of conversion, product pour point is lower, that is the hydrocracking is accompanied by dewaxing. In contrast to dewaxing processes using more shape selective catalysts, bulk conversion, including cracking of aromatic components, teikes place, ensuring acceptably low viscosity in the distillate range product. Thus, the present process is capable of effecting bulk conversion together with simultaneous dewaxing. Moreover, this is achieved with a reduced hydrogen consumption as compared to other types of processes. It is also possible to operate at partial conversion, thus, effecting economies in hydrogen consumption while still meeting product pour point and viscosity requirements.

While not intending to be bound by theory, it is believed that during conversion, aromatics and naphthenes which are present in the feedstock undergo hydrocracking reactions such as dealkylation, ring opening and cracking, followed by

hydrogenation. The long chain normal and slightly branched paraffins which are present in the feedstock, together with the paraffins produced by the hydrocracking of the aromatics are, in addition, converted into products which are less waxy than the straight chain paraffins, thereby effecting simultaneous dewaxing. The process of the present invention produces not only a reduction in the viscosity of the original feed by hydrocracking but also a simultaneous reduction in its pour point by hydrodewaxing.

Another advantage of the process of the invention is its ability to upgrade a highly aromatic feedstock, such as light cycle oil, to a low aromatic product which is rich in

cyclcparaffins and hence desirable for use as a jet fuel or diesel fuel. Still further, the process of the invention can be used to convert heavy aromatic feedstocks to high octane gasoline

(≥ 87RON+O).

Suitable feedstocks for present invention range from relatively light distillate fractions up to high boiling stocks such as whole crude petroleum, reduced crudes, vacuum tower residua, propane deasphalted residua, e.g., brightstock, cycle oils, FCC tower bottoms, gas oils, vacuum gas oils, deasphalted residua and other heavy oils. The feedstock will normally be a C₁₀+ feedstock since light oils will usually be free of

significant quantities of waxy components. However, the process is also particularly useful with waxy distillate stocks such as gas oils, kerosenes, jet fuels, lubricating oil stocks, heating oils, hydrotreated oil stock, furfural-extracted lubricating oil stock and other distillate fractions whose pour point and

viscosity properties need to be maintained within certain

specification limits. Lubricating oil stocks, for example, will generally boil above 230°C (450°F) and more usally above 315°C (600°F). For purposes of this invention, lubricating oil or lube oil is that part of hydrocarbon feedstock having a boiling point of 315°C (600°F) or higher, as deteπnined by ASTM D-1160 test method.

The hydrocarbon feedstocks which can be treated by the hydrocracking process of the present invention will normally boil at a temperature above 65°C (150°F) and more typically above

150°C (300°F). Advantageously, the feedstocks will be those which boil within the range of 180 to 540°C (350°F to 1000°F).

The feedstocks can contain a substantial amount of nitrogen, e.g., at least 10 ppmw, and even more typically 200-1000 ppmw, nitrogen. The feeds can also have a significant sulfur content, ranging from 0.1 wt.% to 5 wt.%. If desired, the feeds can be treated in a known or conventional manner to reduce the sulfur and/or nitrogen content thereof. For example, in the production of jet fuel, a nitrogen- and/or sulfur-contaning feedstock can initially be hydrotreated to convert the heteroatσm impurities to ammonia and hydrogen sulfide. The effluent from the hydrotreater is then fed to a stripper to remove hydrogen, C₁-C₄ hydrocarbons, ammonia and hydrogen sulfide before being subjected to the

hydrocraciking process of the invention.

Conveniently, the hydrocracddng process of the invention also includes the step of contacting the hydrocarbon feed, either in the same or a separate stage, with a second catalyst composition comprising (i) a molecular sieve having a larger pore size than the zeolite of Table 1, e.g., zeolite beta and (ii) at least one hydrogenation component. Such a two catalyst scheme exploits the ability of the hydrocracking catalyst composition of the invention to selectively convert aromatics present in the feedstock to paraffins and naphthenes and the ability of the second hydrocracking catalyst composition to selectively convert the paraffins in the first stage effluent to more highly isαmerized products having lower pour points.

The feedstocks to be treated by the two-catalyst

hydnscracking embodiment of the present invention will ordinarily contain a substantial amount of cyclic hydrocarbons, i.e. aromatic and/or naphthenic hydrocarbons. Advantageously, the feeds can contain 3 wt.% to 40 wt.% aromatics and/or naphthenes. Examples of hydrocarbon streams which can be treated by the two-stage

hydrocracking embodiment are light vacuum gas oils, heavy vacuum gas oils, light catalytic cycle oils, heavy catalytic cycle oils, virgin gas oils, and mixtures thereof.

Alternatively, the process of the invention can be used to convert, in a single hydrocracking stage, dealkylated aromatic product from a catalytic cracking or coking operation to high octane gasoline. Thus, it is characteristic of catalytic cracking that relatively large alkyl groups (typically C₅-C₉ alkyls), which are attached to aromatic moities in the feed, are removed during the course of the cracking while shorter alkyl groups, such as methyl and ethyl remain. Such "substantially dealkylated" cracking products typically have an aromatic content greater than 50 wt%, a hydrogen content below 12.5 wt.%, an API gravity of 5-25 and a boiling range of 195-400°C (385-750°F), more preferably 200-330°C

(400-620°F).

In its calcined form, the zeolite employed in the

hydrocracking catalyst composition of the invention has an X-ray diffraction pattern which includes the lines listed in Table I below:

More specifically, the calcined form may be characterized by an X-ray diffraction pattern including the following lines:

These values were determined by standard techniques.

The radiation was the K-alpha doublet of copper and a

diffractαmeter equipped with a scintillation counter and an

associated computer was used. The peak heights, I, and the

positions as a function of 2 theta, where theta is the Bragg angle, were determined using algorithms on the computer

associated with the diffractσmeter. From these, the relative intensities, 100 I/I_o, where I is the intensity of the strongest line or peak, and d (obs ) the interplanar spacing in Angstroms Units (A), corresponding to the recorded lines, were determined. In Tables I and II, the relative intensities are given in terms of the symbols W=weak, M=medium, S=strong and VS=very strong. In terms of intensities, these may be generally designated as

follows:

W = 0 - 20

M = 20 - 40

S = 40 - 60

VS = 60 - 100

It should be understood that these X-ray diffraction patterns are characteristic of all species of the present zeolite. The sodium form as well as other cationic forms reveal substantially the same pattern with some minor shifts in interplanar spacing and variation in relative intensity. Other minor variations can occur depending on the Y to X, e.g., silicon to aluminum, mole ratio of the particular sample, as well as its degree of thermal treatment.

The synthetic porous crystalline zeolite employed in the hydrocaadcLng catalyst composition of the invention has a composition involving the molar relationship:

X₂O₃:(n)YO₂,

wherein X is a trivalent element, such as aluminum, iron and/or gallium, preferably aluminum, Y is a tetravalent element such as silicon anάyor germanium, preferably silicon, and n is at least 10, usually from 10 to 150, more usually from 10 to 60, and even more usually from 20 to 40. In the as-synthesized form, the zeolite has a formula, on a anhydrous basis and in terms of moles of oxides per n moles of YO₂, as follows: (0.005-0.1)Na₂O: (1-4)R:X₂O₃:nYO₂ wherein R is an organic component. The Na and R components are associated with the zeolite as a result of their presence during crystallization, and are easily removed by post-crystallization methods hereinafter more particularly described.

The above zeolite is thermally stable and exhibits high surface area (greater than 400 m²/gm as measured by the BET

[Bruenauer, Emmet and Teller] test) and unusually large sorption capacity when compared to similar crystal sttructures. In particular the zeolite exhibits equilibrium adsorption values greater than 4.5 wt.% for cyclchexane vapor and greater than 10 wt% for n-hexane vapor. As is evident from the above formula, the zeolite is synthesized nearly free of Na cations. It can, therefore, be used as a hydrocracking catalyst with acid activity without an exchange step. To the extent desired, however, the original sodium cations of the as-synthesized material can be replaced in accordance with techniques well known in the art, at least in part, by ion exchange with other cations. Preferred replacing cations include metal ions, hydrogen ions, hydrogen precursor, e.g., ammonium, ions and mtixtures thereof. Particularly preferred cations are those which tailor its catalytic activity for hydrocracking reactions. These include hydrogen, rare earth metals and metals of Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB and VIII of the Periodic Table of the Elements.

Prior to its use in a hydrocracking catalyst composition, the present zeolite crystals should be subjected to thermal treatment to remove part or all of any organic constituent present therein.

Prior to use, the present zeolite should be dehydrated, at least partially. This can be done by heating the crystals to a temperature in the range of 200°C to 595°C in an inert atmosphere, such as air and nitrogen, and at atmospheric, subattmospheric or superatmospheric pressures for between 30 minutes and 48 hours.

Dehydration can also be performed at room temperature merely by placing the crystalline material in a vacuum, but a longer time is required to obtain a sufficient amount of dehydration.

The zeolite employed in the present invention can be prepared from a reaction mixture containing sources of alkali or alkaline earth metal (M), e.g., sodium or potassium, cation, an oxide of trivalent element X, e.g, alxmdnum, an oxide of tetravalent element Y, e.g., silicon, an organic (R) directing agent,

hexamethylerdeirdne, and water, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:

Reactants Useful Preferred

YO₂/X₂O₃ 10 - 60 10 - 40

H₂O/YO₂ 5 - 100 10 - 50

OH-/YO₂ 0.01 - 1.0 0.1 - 0.5

M/YO₂ 0.01 - 2. 0 0.1 - 1.0

R/YO₂ 0.05 - 1. 0 0.1 - 0.5

In a preferred synthesis method, the YO₂ reactant contains a substantial amount of solid YO₂, e.g., at least 30 wt.% solid YO₂. Where YO₂ is silica, the use of a silica source containing at least 30 wt.% solid silica, e.g., Ultrasil (a

precipitated, spray dried silica conteining 90 wt.% silica) or HiSil (a precipitated hydrated SiO₂ conteining 87 wt.% silica, 6 wt.% free H₂O and 4.5 wt.% bound H₂O of hydration and having a particle size of 0.02 micron) favors crystal formation from the above mdxture. If another source of oxide of silicon, e.g.,

Q-Brand (a sodium silicate comprised of 28.8 wt.% of SiO₂, 8.9 wt.% Na₂O and 62.3 wt.% H₂O) is used, crystallization may yield little or none of the desired crystalline material. Impurity phases of other crystal stxuctures, e.g., ZSM-12, are prepared in the latter circumstance. Preferably, therefore, the YO₂, e.g., silica, source contains at least 30 wfei% solid YO₂, e.g., silica, and more preferably at least 40 wt.% solid YO₂, e.g., silica.

Crystallization can be carried out'at either static or stirred conditions in a suitably reactor vessel such as, e.g., polypropylene jars or teflon lined, or stainless steel autoclaves. Generally crystallization is conducted at a temperature of 80°C to 225°C for 25 hours to 60 days. Thereafter, the crystals are separated from the liquid and recovered.

Crystallization is facilitated by the presence in the reaction mdxture of at least 0.01 percent, preferably 0.10 percent and still more preferably 1 percent, seed crystals (based on total weight) of the crystalline product.

Prior to use in the process of the invention, it may be desirable to incorporate the zeolite described above with another material, or matrix, which is resistant to the temperatures and other conditions employed in the process. Sutih materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and/or metal oxides such as alumina. The latter may be either mterally ocourxing or in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. Use of a material in conjunction with the zeolite, i.e., combined therewith or present during its

synthesis, which itself is catalytically active may change the conversion and/or selectivity of the catalyst. Inactive materials suitably serve as diluents to control the amount of conversion so that hydrocracked products can be obtained economically and orderly without employing other means for controlling the rate of reaction. These materials may be incorporated into naturally occurring clays, e.g., bentonite and kaolin, to improve the crush strength of the catalyst under commercial hydrocaacking conditions. Said materials, i.e., clays, oxides, etc., function as binders for the catalyst. It is desirable to provide a catalyst having good crush strength because in commercial use, it is desirable to prevent the catalyst from breaking down into powder-like materials. These clay binders have been employed normally only for the purpose of improving the crush strength of the catalyst.

Naturally occurring clays which can be composited with the present zeolite include the montmorillαnite and kaolin famdly, which families include the subbentonites, and the kaolins commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite, or anauxite. Such clays can be used in the raw state as originally miined or initially subjected to calcination, acid treatment or chemical modification. Binders useful for compositing with the zeolite also include inorganic oxides, notably alumina.

In addition to the foregoing materials, the zeolite can be composited with a porous matrix material such as silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania as well as ternary compositions such as

silica-alumina-thoria, silica-alumina-zirconia silica-alumina- magnesia and silica-magnesia-zirconia. It may also be advantageous to provide at least a part of the foregoing matrix materials in colloidal form so as to facilitate extrusion of the bound catalyst component(s).

The relative proportions of zeolite and inorganic oxide matrix vary widely, with the zeolite content ranging from 1 to 90 percent by weight and more usually, particularly when the composite is prepared in the form of beads, in the range 2 to 80 weight percent of the composite.

The hydrocracking catalyst composition also contains a hydrogenation component such as one or more of tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese, or one or more noble metals such as platinum, palladium where a

hydrogenation-dehydrogenation function is to be performed. Preferably, the hydrogenation component is a noble metal, preferably platinum, when it is desired to upgrade an aromatic feedstock to jet fuel, and is nickel-tungsten when it is desired to

hydrocrack/hydrodewax a waxy feedstock or to produce high octane gasoline frorni a dealkylated cracking product. The hydrogenation component can be introduced in the catalyst composition by way of cocrystallizatiαn, exchanged into the composition to the extent a Group IIA element, e.g., aluminum, is in the structure, impregnated therein or intimately physically admixed therewith. Such component can be impregnated in, or on, the zeolite such as, for example, by, in the case of platinum, treating the zeolite with a solution containing a platinum irietal-containing ion. Thus, suitable platinum compounds for this purpose include chlooroplatinic acid, platinous chloride and various compounds conteining the platinum amine complex.

The stability of hydrocracking catalyst of the invention may be increased by steairiing which is conveniently effected by contacting the zeolite with, e.g., 5-100% steam at a temperature of at least 300°C (preferably 300-650°C) for at least one hour (preferably 1-200 hours) at a pressure of 101-2,500 kPa. In a more particular embodiinent, the catalyst can be made to undergo steaming with 75-100% steam at 315°-500°C and atmospheric pressure for 2-25 hours.

In general, the hydrocracking process of the invention is conducted at a temperature of 260°C to 450°C, a pressure of

2860-27680 kPa (400 to 4000 psig), a liquid hourly space velocity (LHSV) of 0.1 hr^-1 to 10 hr^-1 and a hydrogen circulation rate of 45 - 1780 Mm³/m³ (250 to 10,000 standard cubic feet per barrel). However, when the process is used to convert aromatic feedstock to high octane gasoline, mild conditions should be employed including a pressure of 500 - 2000 psig (3550 - 15900 kPa), preferably 800 - 1000 psig (5620 - 7000 kPa) a IHSV of 0.1 - 5, preferably 0.5 -

2, and a conversion of 40 - 60% with the catalyst comprising 1-6% nickel and 5-15% tungsten. As previously stated, the hydrocracking process of the invention may also include the step of contacting the hydrocarbon feed, either in the same or a separate stage, with a second

hydrocracking catalyst composition containing a molecular sieve, such as a zeolite Beta, which has a larger pore size than the zeolite of Table 1 and (ii) a hydrogenation component such as any of those previously mentioned. Zeolite Beta is described in U.S. Reissue No. 28,341 (of original U.S. Patent No. 3,308,069) and may be combined with one or more other matrix materials which are resistant to the process conditions, e.g., any of the matrix materials previously identified herein. Where the zeolite beta composition contacts the feed in a separate hydrocraciking stage, this is conveniently effected by passing the effluent from a first stage employing the zeolite of Table 1, without prior separation of lighter products, over the zeolite beta composition. The latter operates under hydroαacking conditions which are within the foregoing ranges and effects selective isomerization of paraffinic components in the first stage effluent. Where the feed is subjected to a single hydrocaacking stage, the zeolite of Table 1 may be composited with the zeolite beta into a single catalyst particle or may be used as a separate

particulate catalyst.

Where the feedstock to be hydrocracked according to the process of the invention contains significant quantities of nitrogen and/or sulfur, it may be desirable initially to subject the feedstock to a conventional hydrotreating process. Hydrotreating can be conducted at low to moderate pressures, typically from 3000 kPa to 10,000 kPa, with the temperature maintained at 350°C to 450°C.

Hydrotreating catalysts include those relatively immune to poisoning by the nitrogenous and sulfurous impurities in the feedstock and generally comprise a non-noble metal component supported on an amorphous, porous carrier such as silica, aluiriina, silica-alumiina or silica-magnesia. Other support materials such as zeolite Y or other large pore zeolites, either alone or in comibination with binders such as silica, alumiina, or silica-alumina, can also be used for this purpose. Because extensive cracking is not desired in the

hydrotreating operation, the acidic functionality of the carrier can be relatively low compared to that of the hydrocracking/dewaxing catalyst described belcw. The metal component can be a single metal from Groups VTB and VIII of the Periodic Table such as nickel, cobalt, chromium, vanadium, molybdenum, tungsten, or a combination of metals such as nidkel-molybdenum, cobalt-nickel, molybdenum, cobalt-molybdenum, nickel-tungsten or nickel-tungsten-titanium.

Generally, the metal component win be selected for good hydrogen transfer activity. The catalyst as a whole will have a good hydrogen transfer activity and minimal cracking characteristics. The catalyst should be pre-sulfided in the normal way in order to convert the metal component (usually inpregnated into the carrier and converted to oxide) to the corresponding sulfide.

In the hydrotreating operation, nitrogen and sulfur impurities are converted to ammonia and hydrogen sulfide,

respectively. At the same time, polycyclic aromatics which are more readily cracked in the present process to form alkyl aromatics. The effluent from the hydrotreating step can be passed directly to the present process without conventional interstage separation of ammonia or hydrogen sulfide although hydrogen quenching can be carried out in order to control the effluent temperature and to control the catalyst temperature in the present process. However, if desired, interstage separation of ammonia and hydrogen sulfide may be carried out.

The invention will now be more particularly described with reference to the Examples and the accompanying drawings, in which:

Figures 1-5 are X-ray diffraction patterns of the calcined crystalline material products of Examples 1, 3, 4, 5 and 7;

Figures 6 and 7 are graphical representations of process performance eata relating to a two-stage catalytic hydrocracking process of this invention; Figures 8 and 9 are graphical representations of process performance data relating to the catalytic hydrocracking/dewaxing process of this invention;

Figure 10 is a graphical comparison of the performance of Pt/zeolite of the invention catalyst with a Pt/zeolite beta catalyst in the hydrocracking of a hydrotreated cycle oil to produce jet fuel; and

Figure 11 is a graphical comparison of the performance of a NiW/zeolite of the invention catalyst with a NiW/USY catalyst and a NiMo/USY catalyst in the hydrocracking of a cycle oil to produce high octane gasoline.

In the Examples, whenever sorption data are set forth for comparison of sorptive capacities for water, cyclchexane and/or n-hexane, they were Equilibrium Adsorption values determined as follows:

A weighed sample of the calcined adsorbent was contacted with the desired pure adsorbate vapor in an adsorption chamber, evacuated to less than 1 mm Hg and contacted with 1.6 kPa (12 Torr) of water vapor or 5.3 kPa (40 Torr) of n-hexane or 5.3 kPa (40 Torr) of cyclchexane vapor, pressures less than the vapor-liquid

equilibrium pressure of the respective adsorbate at 90°C. The pressure was kept constant (within ± 0.5 mm Hg) by addition of adsorbate vapor controlled by a manostat during the adsorption period, which did not exceed 8 hours. As adsorbate was adsorbed by the crystalline zeolite, the decrease in pressure caused the manostat to open a valve which admitted more adsorbate vapor to the chamber to restore the above control pressures. Sorption was complete when the pressure change was not sufficient to activate the manostat. The increase in weight was calculated as the adsorption capacity of the sample in g/100 g of calcined adsorbant. The zeolite of the present invention always exhibits Equilibrium Adsorption values of greater than 4.5 wt.%, usually greater than 7 wt.%, for cyclchexane vapor and greater than 10 wt.% for n-hexane vapor and normally greater than 10 wt.% for water vapor.

When Alpha Value is examined, it is noted that the Alpha Value is an approximate indication of the catalytic cracking activity of the catalyst compared to a standard catalyst and it

When Alpha Value is exarniined, it is noted that the Alpha Value is an approximate indication of the catalytic cradking activity of the catalyst compared to a standard catalyst and it gives the relative rate constant (rate of normal hexane conversion per volume of catalyst per unit time). It is based on the activity of a highly active silica-alumina αacking catalyst taken as an Alpha of 1 (Rate Constant = 0.016 sec^-1). The Alpha Test which is used herein is described in J. Catalysis, 61, pp. 390-396 (1980). It is noted that intrinsic rate constants for many acid-catalyzed reactions are proportional to the Alpha Value for a particular crystalline silicate catalyst, i.e., the rates for toluene disprcportionation, xylene isαmerization, alkene conversion and methanol conversion (see "The Active Side of Acidic Muminosilicate Catalysts," Nature, Vol. 309, No. 5969, pp. 589-591, 14 June 1984). EXAMPLE 1

1 part of sodium aluirdnate (43.5% Al₂O₃, 32.2% Na₂O, 25.6% H₂O) was dissolved in a solution containing 1 part of 50% NaOH solution and 103.13 parts H₂O. To this was added 4.50 parts hexamiethyleneimine. The resulting solution was added to 8.55 parts of Ultrasil, a precipitated, spray-dried silica (about 90% SiO₂).

The reaction mύxture had the following composition, in mole ratios:

SiO₂/Al₂O₃ = 30.0

OH-/SiO₂ = 0.18

H₂O/SiO₂ = 44.9

Na/SiO = 0.18

R/SiO₂ = 0.35 where R is hexaιnethyleneimine.

The mixture was crystallized in a stainless steel reactor, with stirring, at 150°C for 7 days to produce the zeolite of the invention. The crystalline product was filtered, washed with water and dried at 120°C. After a 20 hour calcination at 538°C, the X-ray diffraction pattern contained the major lines listed in Table III. Figure 1 shews the X-ray diffraction pattern of the calcined product. The sorption capacities of the calcined material were measured to be:

H₂O 15.2 wt.%

Cyclchexane 14.6 wt.%

n-Hexane 16.7 wt.%

The surface area of the calcined crystalline material was

measured to be 494 m²/g.

The chemical composition of the uncalcined material was determined to be as follows:

Component wt.%

SiO₂ 66.9

Al₂O₃ 5.40

Na 0.03

N 2.27

Ash 76.3

SiO₂/Al₂O₃, mole ratio - 21.1

EXAMPLE 2

A portion of the calcined crystalline product of Example 1 was tested in the Alpha Test and was found to have an Alpha

Value of 224. EXAMPLES 3-5

Three separate synthesis reaction mixtures were prepared with compositions indicated in Table VI. The mixtures were prepared with sodium aluminate, sodium hydroxide, Ultrasil, hexamet-hyleneimine (R) and water. The miixtures were maintained at 150°C, 143°C and 150°C, respectively, for 7, 8 and 6 days respectively in

stainless steel autoclaves at autogenous pressure. Solids were separated from any unreacted components by filtration and then water washed, followed by drying at 120°C. The product crystals were subjected to X-ray diffraction, sorption, surface area and chemical analyses. The results of sorption, surface area and chemical analyses are also presented in Table IV and the X-ray diffraction patterns are presented in Figures 2, 3 and 4,

respectively. The sorption and surface area measurements were of the calcined product. TABIE IV

Example 3 4 5

Synthesis Mixture, mole ratios

SiO₂/Al₂O₃ 30.0 30.0 30.0

OH-/SiO₂ 0.18 0.18 0.18

H₂O/SiO₂ 19.4 19.4 44.9

Na/SiO₂ 0.18 0.18 0.18

R/SiO₂ 0.35 0.35 0.35 Product Composition, Wt.%

SiO₂ 64.3 68.5 74.5 Al₂O₃ 4.85 5.58 4.87

Na 0.08 0.05 0.01

N 2.40 2.33 2.12

Ash 77.1 77.3 78.2

SiO₂/Al₂O₃, 22.5 20.9 26.0 mole ratio

Adsorption, Wt.%

H₂O 14.9 13.6 14.6

Cyclchexane 12.5 12.2 13.6 n-Hexane 14.6 16.2 19.0

Surface Area, m²/g 481 492 487

EXAMPLE 6

Quantities of the calcined (538°C for 3 hours) crystalline silicate products of Examples 3, 4 and 5 were tested in the Alpha Test and found to have Alpha Values of 227, 180 and 187, respectively.

EXAMPLE 7

To demonstrate a further preparation of the present zeolite, 4.49 parts of hexsimetayleneimine was added to a solution containing 1 part of sodium aluminate, 1 part of 50% NaOH solution and 44.19 parts of H₂O. To the combined solution were added 8.54 parts of Ultrasil silica. The mixture was

crystallized with agitation at 145°C for 59 hours and the resultant product was water washed and dried at 120°C.

The X-ray diffraction pattern of the dried product crystals is presented in Figure 5 and demonstrates the product to be the crystalline material of this invention. Product chemical composition, surface area and adsorption analyses results were as set forth in Table V:

TABLE V

Product Composition (uncalcined)

C 12.1 wt.%

N 1.98 wt.%

Na 640 ppm

Al₂O₃ 5.0 wt.%

SiO₂ 74.9 wt.%

SiO₂/Al₂O₃, mole ratio 25.4

Adsorption, wt.%

Cyclchexane 9.1

N-Hexane 14.9

H₂O 16.8 Surface Area, m²/g 479

EXAMPLE 8

25g grams of solid crystal product from Example 7 were calcined in a flowing nitrogen atmospheres at 538°C for 5 hours, followed by purging with 5% oxygen gas (balance N₂) for another 16 hours at 538°C.

Individual 3g samples of the calcined material were ion-exchanged with 100 ml of 0.1N TEABr, TPABr and LaCl₃ solution separately. Each exchange was carried out at ambient temperature for 24 hours and repeated three times. The exchanged samples were collected by filtration, water-washed to be halide-free and dried. The compositions of the exchanged samples are tabulated below demcmstxating the exchange capacity of the present crystalline silicate for different ions. Exchange lons TEA TPA La

Ionic Composition, wt. %

Na 0.095 0.089 0.063

N 0.30 0.38 0.03

C 2.89 3.63 -

La - - 1.04

EXAMPLE 9

The La-exchanged sample from Example 8 was sized to 14 to 25 mesh and then calcined in air at 538°C for 3 hours. The calcined material had an Alpha Value of 173.

EXAMPLE 10

The calcined sample La-exchanged material from Example 9 was severely steamed at 649°C in 100% steam for 2 hours. The steamed sample had an Alpha Value of 22, demonstrating that the zeolite had very good stability under severe hydrothermal

treatment.

EXAMPLE 11

This example illustrates the preparation of

NiW/zeolite/Al203 catalyst which provides the first hydrocracking catalyst composition employed in the hydrocracking process

illustrated in Example 13, infra.

The zeolite component of the first hydrocracldLng catalyst composition was synthesized fcy adding 4.49 parts quantity of hexairethyleneimine to a mixture containing 1.00 part sodium

alumiinate, 1.00 part 50% NaOH, 8.54 parts Ultrasil VN3 and 44.19 parts deionized H2O. The reaction mixture was heated to 143°C (290°F) and stirred in an autoclave at that temperature for

crystallization. After full crystallinity was achieved, the majority of the hexametftyleneimine was removed from the autoclave by controlled distillation and the zeolite crystals separated from the reiraining liquid by filtration, washed with deionized water and dried.

A portion of the zeolite crystals was combined with A1203 to form a mixture of 65 parts, by weight, zeolite and 35 parts A1203. Water was added to this mixture to allow the resulting catalysts to be formed into extrudates. The catalyst was activated by calcining at 480°C (900°F) in 3v/v/min nitrogen for three hours, then treated with 50 vol.% air/50 vol% N₂ at 3v/v/mtin, also at 480°C (900°F) for 1 hour. The calcination was completed by raising the teriperature to 540°C (1000°F) at 3°C/mιin and finally switohing to 100% air (3v/v/min) and holding at 540°C (1000°F) for three hours. The calcined catalyst had an alpha value of 213. This material was then steamed at 480°C (900°F) in 100% steam to 12 hours. The resulting catalyst had an alpha value of 35.

The steamed extrudate was impregnated with airamonium metatungstate via a known and conventional incipient wetness technique at room temperature, dried overnitght at 120°C (250°F), calcined in dry air at 1°C (1.8°F)/mrln to 540°C (1000°F) and held at this temperature in flowing air for three hours.

The tungsten-containing catalyst was then impregnated via the incipient wetness technique with nickel nitrate, dried overniciht at 120°C (250°F), and then calcined in air using the previously described procedure. The finished NiW/zeolite/Al₂O₃ catalyst had the properties shown in Table VI as follows:

TABLE VI

Properties of NiW/zeolite/Al₂O₃

First Hydrocracking Catalyst Composition Density, g/cm³

Packed 0.48

Particle 0.82

Real 2.57 Pore Volume, cm³/g 0.83

Surface Area, m²/g 451

Pore Diameter, Angstroms 74

Alpha after Steaming 35

Sodium, ppm 132

Nickel, wt.% 3.12

Tungsten, wt.% 7.85

EXAMPLE 12

This example illustrates the preparation of NiW/zeolite Beta/Al₂O₃ used to provide the second hydrocracking catalyst composition employed in the hydrocracking process illustrated in Example 13, infra.

The zeolite Beta component of the second hydrocracking catalyst composition was synthesized substantially as described in U.S. Reissue No. 28,341 (of original U.S. Patent No.

3,308,069). The zeolite was then ammonium exchanged twice at room temperature with 5 ml/g IN ammonium nitrate. A 65 wt.% zeolite Beta/35 wt.% Al₂O₃ catalyst composition was prepared from this zeolite by extrusion. The material was dried overnight at 120°C (250°F), calcined at 540°C (1000°F) in 3 v/v/min N₂ at a heating rate of 5°F/min, held at 540°C (1000°F) for three hours in 3 v/v/min N₂, then treated with air for three hours at 3 v/v/min also at 540°C (1000°F). The calcined catalyst had an alpha of 380. This material was then steamed at 540°C (1000°F) in 100% steam for 10 hours.

The steamed extrudate was impregnated with ammonium metatungstete via the incipient wetness technique at room terrperature, dried overnight at 120°C (250°F), calcined in dry air at 1°C (1.8°F)/min to 540°C (1000°F) and held at this te-mperature in flcwing air for three hours.

The tungsten containing catalyst was then impregnated via the incipient wetness technique with nickel nitrate, dried overnight at 120°C (250°F), and then calcined in air using the same procedure described above. The finished NiW/zeolite

Beta/Al₂O₃ catalyst had the properties shown in Table VII as follows: TABLE VII

Properties of NiW/zeolite Beta/Al₂O₃

Second Hydrocracking Catalyst Composition Density, g/cm³

Packed 0.54

Particle 0.96

Real 2.64 Pore Volume, cm³ /g 0.67

Surface Area, m² /g 384

Pore Diameter, Angstroms 69

Alpha after Steaming 52

Sodium, ppm 105

Nickel, wt.% 3.29

Tungsten, wt.% 7.39 EXAMPLE 13

Both the first and second hydrocracking catalyst competitions (Examples 11 and 12, respectively) were individually compared for their activity and selectivity in converting a vacuum gas oil (VGO) having the properties shown in Table VIII as follows:

TABLE VIII

Properties of Vacuum Gas oil Distillate

Viscosity (SUS) 150

Distillation, °F(°C)

1% 653 (345)

5% 696 (369) 50% 784 (418) 95% 877 (469) 99% 915 (491) Hydrogen, % 13. 40

Nitrogen, ppm 620

Sulfur, % 0. 43

Paraffins 30.7

Mononaphthenes 16.9

Polynaphthenes 17.7

Aromatics 34. 7

KV 40°C, cs 26. 45

KV 100°C, cs 4.805

Pour Point, °F(°C) 95 (35)

Cloud Point, °F(°C) 112 (44)

Flash, COC, °F(°C) 421 (216) Reaction conditions were as follows:

LHSV, hr^{- 1} 0.4 to 0.6

Temperature, °F(°C) 670 to 750 (350 - 400) Pressure, psig(kPa) 1400 to 1500 (9750 - 10440) H₂ circulation 3000 to 5000 scf H₂/BBL

(534 to 890 Nm³H₂/m³)

Prior to contacting with the vacuum gas oil, both catalyst compositions were presulfided with a mixture of 2% H₂S in H₂ at 240-380 kPa (20 to 40 psig). The presulfiding procedure involved increcising the temperature from 200 to 400°C (400°F to

750°F) over the course of four hours.

The compositions of the 343°C+ (650°F+) fractions resulting from the hydrocracking of the VGO over the first and second

hydrocracking catalyst compositions are shown in Table IX as follows:

TABLE IX

Hydrocacking of VGO Over

Catalyst of Invention

Conversion, wt.% Feed 44 63 76 82

Analysis of 343°C+

Fraction

Paraffins 30.7 27.6 35.9 34.4 34.4

Naphthenes 34.6 56.0 51.6 55.2 51.4

Aromatics 34.7 16.4 12.5 10.4 14.2

Hydrocracking of VGO Over

Zeolite Beta Catalyst

Conversion, wt.% Feed 44 54 67 87

Analysis of 343°C+

Fraction

Paraffins 30.7 34.0 29.1 17.3 10.3

Naphthenes 34.6 55.6 59.3 61.9 67.3

Aromatics 34.7 10.4 11.6 20.8 22.4 The data in Table IX show that the hydrocaacking catalyst composition of the invention selectively converts aromatics and concentrates paraffins and naphthenes in the heavy fraction. The zeolite Beta-based hydrocxacking catalyst composition, by contrast, primarily converts paraffins while concentrating aromatics. This can also be seen by examining the compositional reaction pathways as shewn in Figures 6 and 7.

These two Figures compare the relative conversions of the paraffin, raphthene, and aromatic fractions in the 343°C+ fraction versus overall conversion to 343°C- for both catalysts. Above 50 wt.% conversion, the zeolite beta hydrocracking catalyst composition catalyst is more selective for paraffins conversion and less selective for aromatics conversion. The opposite is true of the first hydrocraclcing catalyst composition of the invention.

EXAMPLE 14

A sample of the zeolite produced as in Example 11 was used to produce a nickel and tungsten-containing catalyst composition for use in the single stage hydrocracking/dewaxing process of Example 16, infra. Initially, the zeolite (65 wt%) was mulled with Kaiser SA alumina (35 wt.%) and the resultant imixture was extruded with sufficient added water to provide a 1.6mm (1/16 inch) diameter extrudate and the extrudate was dried at 120°C (250°F). The dried extrudate was then heated at 3°C (5°F)/minute to 480°C (900°F) in flowing nitrogen; held at 480°C (900°F) for 3 hours in flowing nitrogen; and held at 480°C (900°F) for 1 hour in a 50/50 volume ratio of air/nitrogen. The extrudate was then heated to 540°C (1000°F) at 3°C (5°F)/minute in the 50/50 air nitrogen/mixture, and held at 540°C (1000°F) for 3 hours.

The catalyst composition thus prepared was found to have the following physical properties (Table X): TABLE X

Alpha Value 213

Sodium, ppm 630

Density, g/cc

Packed 0.48

Particle 0.82

Real 2.57

Pore Volume, cc/g 0.83

Surface Area, m /g 451

Pore Diameter, Angstroms 74

Crush, lb/in² (kg/m²) 77 (5.4 X 10⁴)

The final catalyst composition was prepared by first contacting the zeolite/Al₂O₃ product with 100% steam for 12 hours at 480°C (900°F). The resulting steamed composition was dried for 2 hours at 120°C (250°F) and was found to have an alpha value of 30.

The dried composition was then impregnated to incipient wetness at room temperature with a solution of 0.154 g/g

of(NH₄) ₆W₁₂O ·9H₂O, dried in air at room temperature for 4

hours, then dried at 120°C (250°F) overnight.

The dried composition was then calcined in flowing dry air at 19°C (34°F)/minute to 540°C (1000°F), and held at this temperature for 3 hours in the flowing dry air.

The resulting composition was then impregnated to incipient wetness at room temperature with a solution of 0.206 g/g of

Ni(NO₃)₂·6H₂O, dried in air at room temperature for 4 hours, then dried at 120°C (250°F) overnight.

The dried composition was then calcined in flowing dry air at 19°C (34°F)/minute to 540°C (1000°F) and held at this temperature for 3 hours in the flowing air. The final composition contained 3.3 wt% Ni and 8.6 wt% W. EXAMPLE 15

A nickel and tungsten-containing alumina-bound USY catalyst composition was prepared for comparison with the nickel and tungsten-containing catalyst composition of Example 11 for catalyzing the hydrocracking/dewaxing process illustrated in

Example 18, infra.

The USY catalyst composition was prepared by mixing 65 wt% USY zeolite with 35 wt% alumina, extruding, exchanging with NH₄NO₃ solution, steaming with 540°C (1000°F) steam for 10 hours and co-impregnating with a solution containing nickel and

tungsten salts.

The final USY catalyst composition contained -2.0 wt% Ni and 6.0 wt% W.

EXAMPLE 16

The catalysts prepared according to Examples 14 and 15 were used simultaneously to hydrocrack/dewax separate samples of the vacuum gas oil employed in Example 13. In each case

conversion was carried out at a pressure of 9690 kPa (1400 psig), a temperature of 354-418°C (670-785°F), an IHSV of 0.5-1.0 and a hydrogen circulation rate of 710-1600 Mm³/m³ (4000-9000 scf/bbl).

At 75% conversion, the product yield results were as presented in Table XI below. All material balances were between 90-100% recovery, mostly greater than 95%.

TABLE XI Product Yields at 75% Conversion

166-343°C C₅-166°C

(330-650°F) (C₅-330°F)

Catalyst Distillate, wt.% Naptha, wt.% C₁-C₄, wt.%

(Example 15) 25 36 14 (Example 16) 33 37 5 Figure 8 shews measured pour points of the product at different conversions during the process over each catalyst. The plotted date shew that hydrocracking/dewaxing over the zeolite of the invention provides a product having significantly lower pour point for a given rate of conversion.

EXAMPLE 17

This example provides a comparison between the catalyst composition of Example 14 (invention) and the beta catalyst

composition of Example 12 for the conversion of the heavy gas oil employed in Example 16.

Presulfiding of the catalysts was accomplished with a mixture of 2% H₂S in H₂ mixture at 240-380 kPa (20-40 psig) with a temperature increase of 200-400°C (400-750°F) over a period of 4 hours. Reaction conditions were varied over the following ranges:

Temperature: 670 to 750°F (350-400°C)

Pressure: 1400 to 1500 psig (9750-10440 kPa)

LHSV: 0.4 to 0.6

Η₂ Circulation: 3000 to 5000 scf/bbl (530-890 Nm³/m³)

The reported conversions are based on the 343°C+

(650°F+) portion of the feed. The results of the conversion employing the catalyst of the invention (Example 14) are set forth in Table XII and employing the zeolite beta catalyst of

Example 12 are set forth in Table XIII as follows:

As shown in Tables XII and XIII, although catalyst compositions achieve pour point reduction, at conversions below 50%, where the catalyst of the invention makes less distillate and more gas than zeolite Beta, the former lowers the pour point to a greater extent (see Figure 9). At higher conversion levels, zeolite Beta catalyst is superior in this regard. However, the lew paraffin/high aromatic content of the zeolite beta producs at high conversion levels results in these products having low viscosity indexes.

The activity of the catalyst cxatpositions including the zeolite of the invention and zeolite beta were compared at 60% conversion of the heavy gas oil of Table VIII (Example 17). At conditions of 9960 kPa (1430 psig), 0.54 IHSV and 800 Nm³/m³ (4500 scf H₂/bbl) feed, the temperature required to achieve 60% conversion was 377°C (711ºF) for zeolite Beta and 383°C (721°F) for zeolite of the invention. Figure 9 plots the distillate yield obtained with the two catalysts as a function of conversion. Both zeolite catalysts produced about the same maximum amount of distillate, but the maximum for zeolite of the invention occured at a

significantly higher conversion level. Above 70% conversion, zeolite of the invention provides significantly better

selectivity than that of the zeolite Bete.

However, when employed in combination, the differences in catalytic properties of the zeolite of the invention and zeolite Beta for the simultaneous hydrocracking and dewaxing of a heavy hydrocarbon feed complement each other and make it possible to improve the viscosity of the product while simultaneously achieving a lew pour point.

EXAMPLE 18

This Example illustrates the use of a zlolite of Table I in the production of jet fuel from an 80% light cycle oil product of an FCC unit. The product was initially hydrotreated in

conventional manner and, after removal of H₂S, NH₃ and light gases, the hydrotreated product had the properties listed in

Table XIV. TABLE XLV

General Properties

API Gravity 28.5

Hydrogen, wt.% 12.59

Sulfur, ppmw <20

Nitrogen, ppmw <2

Freeze Point, °F(°C 5(-4)

Smoke Point, mm

FIA Composition, vol.

Saturates 39.7

Olefins 1.8

Aromatics 58.5

Distillation, °F(°Cl

IBP 162(72)

10% 389(198)

30% 458(237)

50% 505(263)

70% 556(291)

90% 643(339)

EP 786(419)

The zeolite catalyst, prepared in accordance with the method described in Example 1, was initially exchanged with amimonium nitrate and then mixed with an alumina binder. The mixture was mulled, extruded, dried at 250°F (120°C) and then calcined in nitrogen at 1000°F (540°C) for 3 hours. After humidication the mixture was exchanged with 1 N ammonium nitrate, dried and calcined again in nitrogen at 1000°F (540°C). The mixture was again humidified, exchanged with Pt(ML) Cl solution for 8 hours, rinsed, dried and calcined at 660°F (350°C) in air. The properties of the reultant catalyst and a comparison zeolite beta catalyst are shewn in Table XV.

TABIE XV

Pt/Table 1 Zeolite Pt/Beta

Composition, wt.% Zeolite 65 65

Platinum 0.66 0.56

Density, g/cc

Packed 0.45 0.53

Particle 0.73 0.88

Real 2.60 2.57

Physical Properties

Pore Volume, cc/g 0.99 0.75

Surface Area, m²/g 372 369

Average Pore

Diameter, A 106 81

Each catalyst was then used to hydrocrack the feedstock described in Table XIV in a pilot unit cperated at 1.0 hr^-1 LHSV,

1500 psig (10445 kPa) inlet hydrogen pressure and 5000 scf/bbl (890 Nm³/m³) of once-through hydrogen cxirculation rate. The 390°F⁺ (199°C⁺) bottoms product passed the specifications for the JP-8X fuel for both catalysts, as shown in

Table XVI. However, the zeolite of the invention produced a

390°F⁺ (199°C⁺) bottoms product having a higher density and a

significantly higher volumetric heat of comibustion than that from the Pt/zeolite beta.

API Gravity 32.1 32.8 33.2 34.4 <37

Freeze Point, °F(°C) <-85(-65) <-85(-65) <-85(-65) <-85(-65) <-51(-46)

Smoke Point, mm 21.0 21.0 21.5 22.0 >15

Naphthalenes, vol.% 0.13 <0.1 <0.1 <0.1 --

Net Heat of Combustion

BlU/lb (kJ/kg x 10³) 18444 18443 18487 18596 --

(42.86) (42.86) (42.96) (43.21)

BlU/gallon

(kJ/m³ x 10³) 132852 132290 132270 132069 -- (37.03) (36.87) (36.87) (36.81) As shown in Table XVII the same conclusions can be

reached in the comparison of the 250°F⁺ (120°C⁺) bottoms product.

Also noteworthy is that zeolite of the invention can produce

premium high quality jet fuel at conversions as low as 37.3%.

API Gravity 34.4 35.8 36.9 42.4 <37

Freeze Point, °F(°C) <-85(-65) <-85(-65) <-85(-65) <-85(-65) <-51(-46)

Smoke Point, mm 21.0 25.5 >15

Naphthalenes, vol.% <0.1 <0.1 <0.1 <0.1 -- Aromatics, vol. % <0.5 <0.5 <0.5 1.5 --

Net Heat of Combustion

BlU/lb (kJ/kg X 10³) 18431 18443 18460 18480 --

(42.83) (42.86) (42.90) (42.94) BIU/gallon

(kJ/m³ x 10³) 130915 129912 129183 125238 -- (36.49) (36.21) (36.01) (34.91) Fig. 10 charts the catalyst performance of Pt/Table 1 zeolite vs. Pt/beta at 60% conversion. As can be seen, Pt/Table 1 zeolite required a higher tempprature initially to achieve 60% conversion, i.e. , was Initially less active than Pt/beta, but after 8 days on stream had a higher activity than Pt/beta and exhibited overall a stable level of activity without rapid aging as shewn by Pt/beta.

Moreover, the naptha fraction produced from Pt/Table 1 zeolite was rich in cycloparaffins. Table XVIII shows a comparison between the naphtha fractions produced by the two zeolites. The naphtha fractions (C₅ - 250°F (120°C) naphtha) of Pt/Table 1 zeolite had a higher percentage of cycloparaffins and a higher density than that of the naphtha from Pt/beta. Even at 37.3% conversion the 250-390°F (120-299°C) naphtha fraction of Pt/Table 1 zeolite had a higher octane than that of Pt/beta.

The bottoms of this process, almost free in sulfur and aromatics, is a premium diesel fuel as well as a premium jet fuel. Thus, the Pt/Table 1 zeolite catalyst significantly improves process flexibility and makes possible the coproduction of gasoline (naphtha) and jet fuel (or diesel fuel) by

hydrocaacking.

EXAMPLE 19

This Example compares the zeolite of the invention with USY as a catayst in the hydrocracking of a highly aromatic cycle oil to produce high octane gasoline. The feedstock employed was a full range cycle oil having the properties set out in Table XIX.

TABLE XIX

Feedstock Properties

General Properties

API Gravity 15.5

Hydrogen, wt.% 9.41

Sulfur, ppmw 3.0

Nitrogen, ppmw 220

Basic Nitrogen, ppmw 42

Composition, wt.%

Paraffins 14.3

Naphthenes 7.4

Aromatics 78.3

Distillation, °F(°C)

IBP 426(219)

5% 479 (248)

10% 481(249)

30% 503 (262)

50% 519 (271)

70% 537 (281)

90% 571(299)

95% 596(313)

EP 626(330) In preparing the catalyst of the invention, zeolite

crystals produced by the process of Example 7 were dried and then mixed with Kaiser SA alumina (65 wt.% zeolite/35 wt.% alumina).

The resultant mixutre was mulled, extruded with sufficient added water to provide a 1/16 inch (0.16 cm) diameter extrudate and the extrudate was dried at 250°F (120°C). The dried extrudate was then heated at 5°F (3°C)/minute to 900°F (480°C) in flowing

nitrogen; held at 900°F (480°C) for 3 hours in flowing nitrogen; and held at 900°F (480°C) for 1 hour in a 50/50 volume ratio of air/nitrogen. The extrudate was then heated to 1000°F (540°C) at 5°F (3°C)/minute in the 50/50 air nitxogen/mixture, and held at 1000-F (540°C) for 3 hours.

The dried composition was then impregnated to incipient wetness at room temperature with a solution of 0,176 g/g of

ammonium mete tungstate (92.1% WO₃ wt.), dried in air at room teiiperature for 4 hours, then dried at 250°F (120°C) overnight.

The dried composition was then calcined in flowing dry air at

(5/v/v/min), heating at 5°F (3°C)/min. to 1000°F (540°C), and held at 1000°F (540°C) for 3 hours in the flowing dry air.

The resulting composition was then impregnated in the same way with a solution of 0.213 g/g of Ni(NO₃)₂.6H₂O to produce a final catalyst composition contaiing 4.2 wt.% Ni and 10.8 wt.%W and having the properties shown in Table XX.

For comparison purposes, two USY catalyst compositions were prepared, one containing nickel and molybdenum and the other containing nickel and tungsten. Each USY catalyst composition was prepared by extruding a mixture of 75 wt.% USY zeolite with 25 wt.% alumina, drying the extrudate at 250°F (120°C) and then calcining for 3 hours at 1000°F (540°C). The calcined extrudate was then exchanged with IN ammonium nitrate solution, dried and calcined again.

After two more exchanges with ammonium nitrate followed by drying and calcining for each exchange, the composition was divided into two samples. One sample was impregnated (without prior steaiming) to incipient wetness with a solution of ammonium heptamolybdate/ nickel nitrate, dried and calcined. The other sample was steamed with 1000°F (540°C) steam for 10 hours and co-impregnated with a solution containing nickel and tungsten salts. The properties of the resultant catalyst are .summarized in Table XX.

TABLE XX

Catalyst Properties

NiW/Table 1 Zeolite NiMo/USY NiW/USY

Steaming of Zeolite No No Yes

Composition, wt.

Zeolite* 65 75 75

Nickel 4.2 4.1 4.0

Molybdenum -- 6.3

Tungsten 10.8 9.4

Density, g/cc

Particle 0.951 1.052 1.087 Real 2.957 2.759 2.915

Physical Properties

Pore Vol., cc/g 0.713 0.588 0.577

Surface Area, m²/g 303 412 391

Pore diameter, A 94 57 59

Alpha Number* 259 217 73

* Prior to the metal additions Each catalyst was used to hydrocrack feedstock described in Table XIX in a pilot unit operated at 0.75 LHSV, 900 psig (6300 kPa) inlet hydrogen pressure and at 45% conversion [to 390°F (199°C)-boiling]. The results of the tests are illustrated in Fig. 11 from which it will bfe seen that the product for the NiW/Table 1 zeolite catalyst had an octane rating of over 96 after 10 days and over 98 after 15 days, m contrast, the octane rating for the products of the NiMo/USY and NiW/USY catalysts remained below 90 during the same on-stream time periods.

Claims

CLAIMS:

1. A hydrocracking process comprising the step of contacting a hydrocarbon stream under hydrocracking conditions and in the presence of hydrogen with a hydrocaacking catalyst composition comprising a synthetic porous crystalline zeolite having, in its calcined form, an X-ray diffraction pattern with lines set forth in Table I of the specification.

2. The process of Claim 1 wherein the synthetic porous crystalline zeolite has, in its calcined form, an X-ray

diffraction pattern with lines set forth in Table II of the specification.

3. The process of claim 1 or claim 2 wherein the zeolite has equilibrium adsorption capacities of greater than 4.5 wt.% for cyclchexane vapor and greater than 10 wt.% for n-hexane vapor.

4. The process of Claim 1 wherein the synthetic porous crystalline material has a composition comprising the molar relationship

X₂O₃:(n)YO₂,

wherein n is at least 10, X is a trivalent element and Y is a tetravalent element.

5. The process of Claim 4 wherein X comprises aluminum and Y comprises silicon.

6. The process of Claim 1 wherein said hydrocaacking catalyst composition also comprises a hydrogenation component.

7. The process of Claim 1 wherein said hydrocracking conditions include a temperature of 260°C to 450°C, a pressure of 2860 to 27680 kPa, an LHSV of 0.1 to 10, and a hydrogen circulation rate of 45 to 1780 Nm³/m³.

8. The process of Claim 1 wherein the hydrocarbon stream contains waxy paraffins and said contacting step reduces the pour point of the hydrocarbon stream.

9. The process of Claim 1 and also including the step of subjecting the hydrocarbon stream, either in the same or a separate stage as said contacting step, to hydrocracking with a further hydrocracking catalyst composition comprising a large pore molecular sieve and ation component.

10. The process of Claim 9 wherein said large pore molecular sieve is zeolite beta.

11. The process of Claim 6 wherein the hydrogenation component is a noble metal, the hydrocarbon stream contains at least 50% by weight aromatics and the final product is a jet or diesel fuel.

12. The process of Claim 6 wherein the hydrogenation component includes nickel and tungsten, the process conditions include a pressure of 3550 - 15900 kPa and an IHSV of 0.1 - 5 and the product is gasoline.