Hydrocracking process and catalyst

A catalytic composite is disclosed which catalyst comprises a silica-alumina carrier material, a nickel component and a vanadium component, and which catalyst is useful for the conversion of hydrocarbons. A preferred method of preparation comprises the incorporation of the vanadium component from an alcoholic solution of a vanadium compound.

BACKGROUND OF THE INVENTION 
The field of art to which this invention pertains is the catalytic 
conversion of hydrocarbons. This invention also relates to hydrocarbon 
conversion catalysts and their methods of manufacture. The catalyst 
composite of the present invention demonstrates unexpected and exceptional 
activity, selectivity and resistance to deactivation when employed in a 
hydrocarbon conversion process. More particularly, the invention relates 
to a catalyst which is useful for performing destructive hydrogenation or 
hydrocracking of hydrocarbons. 
DESCRIPTION OF THE PRIOR ART 
Destructive hydrogenation by catalytic means, more commonly called 
hydrocracking, is old and well-known in the prior art. Destructive 
hydrogenation of the hydrocarbon oil, which may be high-boiling fractions, 
such as gas oils, topped crude, shale oil, and tar sand extract, generally 
is performed at relatively high temperature and pressures of the order of 
700.degree. F. and 1000 psig and upward. Catalysts for the destructive 
hydrogenation of hydrocarbons are generally a combination of hydrogenation 
and cracking catalysts. 
Although hydrocracking can be effected thermally, catalysts offer a 
substantial improvement. The prior art hydroconversion catalyst will 
typically comprise a cracking component, for example, silica, alumina, 
silica-alumina, or other acid-acting refractory inorganic oxide, and a 
hydrogenation component. 
Hydrocracking catalysts containing a crystalline aluminosilicate dispersed 
in the acid-acting refractory inorganic oxide have been shown to be 
particularly effective in the hydrocracking process. One or more 
hydrogenation components have been selected by the prior art to serve as 
the hydrogenation component in hydroconversion catalysts. The prior art 
has broadly taught that hydrogenation components may be selected from at 
least the following metals: iron, cobalt, nickel, ruthenium, rhodium, 
palladium, osmium, iridium, platinum, chromium, molybdenum, tungsten, 
vanadium, niobium and tantalum. 
In U.S. Pat. No. 3,956,104 (Hilfman et al), a preferred hydrocracking 
catalyst contained molybdenum and nickel. In U.S. Pat. No. 3,931,048 
(Hilfman et al), a preferred hydrocracking catalyst comprises nickel, 
tungsten and a silica-alumina carrier material. U.S. Pat. No. 3,184,,404 
(Flinn et al) teaches the combination of tungsten and a metal selected 
from Group VIII of the Periodic Table of the Elements on an alumina 
support as an effective hydrocracking catalyst. The hereinabove mentioned 
patents relate to hydrocracking catalysts which are associated with 
refractory inorganic oxide support materials and which patents provide 
examples of some of the prior art catalysts. 
Another U.S. Pat. No. 3,825,504 (Hilfman) teaches the use and preparation 
of a co-extruded hydrocracking catalyst comprising a nickel component and 
an alumina-containing porous carrier material. According to this patent, a 
preferred method of preparation is the physical admixture of a 
finely-divided nickel salt and a vanadium salt with a silica-alumina 
carrier material. This solid mixture is then ground to a powder having a 
size of about 40 mesh and extruded. The resulting extrudates are dried and 
calcined to yield a catalyst containing less than about 0.1 weight percent 
nickel aluminate. According to the patentee, the presence of the vanadium 
salt is critical for a co-extruded catalyst and inhibits the reaction of 
the nickel component with the alumina which produces an active catalyst. 
In the art of hydrocarbon processing, such as fluid catalytic cracking 
(FCC), it is well known to use an amorphous silica-alumina catalyst for 
the conversion of the hydrocarbons. FCC is distinguished from 
hydrocracking by FCC's relatively low pressure of less than about 100 psig 
and the absence of externally added hydrogen. In process units which are 
used for the conversion of residual crude oil, particularly FCC units, the 
silica-alumina catalyst becomes contaminated with trace quantities of 
nickel and vanadium which are quantitatively removed from the crude oil. 
These indigenous contaminating metals are usually present in crude oil in 
amounts of 200 ppm or less, but after extended processing of 
metal-contaminated crude oil, the catalyst accumulates an appreciable 
quantity of metals which is extremely undesirable from the standpoint of 
FCC processing. Attenuation or actual removal of these undesirable metal 
accumulations is deemed necessary for the economic operation of a residual 
oil FCC unit. Therefore, the FCC process cannot profitably utilize a 
catalyst comprising active catalytic metals of nickel and vanadium and in 
any event does not employ the addition of hydrogen from an external 
source. Furthermore, the inadvertent formulation of the catalyst 
comprising nickel, vanadium and silica-alumina during the processing of 
metal-containing feedstocks in an FCC unit while using silica-alumina 
catalyst involves the topical deposition of nickel and vanadium upon the 
silica-alumina particles by the adhesion of organometallic components 
which are contained in the metal-containing feedstocks, in 
contradistinction to the formulation of the catalyst by the method of the 
present invention as hereinafter discussed. By the very nature of the FCC 
process, the silica-alumina particles together with the organometallic 
components are subjected to high temperature regeneration wherein the coke 
or carbon is burned off. After regeneration of the catalyst, it is 
believed that because of the method of incorporation, the nickel and 
vanadium is situated in a random manner on the surface of the 
silica-alumina particles which results in a distinctly different 
composition of matter as compared to the catalyst composition of the 
present invention. 
Another mode of hydroconversion of hydrocarbons is the use of unsupported 
finely divided catalyst in a slurry hydrocarbon conversion process. This 
process utilizes a suspension of finely divided catalyst which is admixed 
with the hydrocarbon feedstock during the conversion processing step. For 
example, U.S. Pat. No. 3,165,463 (Gleim et al) teaches a process for the 
hydrorefining of a hydrocarbon charge stock with a finely divided slurry 
catalyst which is selected from vanadium, niobium, tantalum, molybdenum, 
tungsten, iron, cobalt and nickel. 
It is generally recognized that catalysis is a mechanism particularly noted 
for its unpredictable nature. Minor variations in a method of manufacture 
often result in an unexpected improvement in the catalyst product with 
respect to a given hydrocarbon conversion reaction. The improvement may be 
the result of an undetermined alteration in the physical character and/or 
composition of the catalyst product difficult to define and apparent only 
as a result of the unexpected improvement in the catalyst activity, 
selectivity and/or stability. 
One of the discoveries of the present invention is a novel catalyst which 
exhibits improved and unexpected hydrocarbon conversion characteristics. 
The present invention also describes the utilization of the novel catalyst 
in a hydrocarbon conversion process. Another embodiment of the present 
invention describes methods for preparing catalysts. 
SUMMARY OF THE INVENTION 
Accordingly, the invention is, in one embodiment a catalytic composite 
comprising a combination of a carrier material, a nickel component which 
is incorporated in the composite in an amount from about 0.1 to about 10 
weight percent of the composite based on the elemental metal and a 
vanadium component which is incorporated in the catalytic composite by 
means of an alcoholic solution of a vanadium compound in an amount from 
about 0.1 to about 10 weight percent of the composite based on the 
elemental metal, the carrier material comprising a co-gelled 
silica-alumina carrier material which comprises from about 20 weight 
percent to about 80 weight percent silica. 
In a second embodiment, the invention is a process for converting a 
hydrocarbon charge stock into lower boiling hydrocarbon products which 
comprises reacting the charge stock with an external source of hydrogen at 
hydrocracking conditions in contact with a catalytic composite comprising 
a combination of a carrier material, a nickel component which is 
incorporated in the composite in an amount from about 0.1 to about 10 
weight percent of the composite based on the elemental metal and a 
vanadium component which is incorporated in the catalytic composite by 
means of an alcoholic solution of a vanadium compound in an amount from 
about 0.1 to about 10 weight percent of the composite based on the 
elemental metal, the carrier material comprising a co-gelled 
silica-alumina carrier material which comprises from about 20 weight 
percent to about 80 weight percent silica. 
In a third embodiment, the invention is a method for the preparation of 
catalysts, having hydrocracking activity, comprising a combination of a 
carrier material, a nickel component which is incorporated in the 
composite in an amount from about 0.1 to about 10 weight percent of the 
composite based on the elemental metal and a vanadium component which is 
incorporated in the catalytic composite by means of an alcoholic solution 
of a vanadium compound in an amount from about 0.1 to about 10 weight 
percent of the composite based on the elemental metal, the carrier 
material comprising a co-gelled silica-alumina carrier material which 
comprises from about 20 weight percent to about 80 weight percent silica, 
which method comprises: (a) the sequential incorporation of each metal 
component on the carrier material; and (b) the calcination of the carrier 
material following each metal component incorporation. 
In a fourth embodiment, the invention is a method for the preparation of 
catalysts, having hydrocracking activity, comprising a combination of a 
catalytic composite comprising a combination of a carrier material, a 
nickel component in an amount from about 0.1 to about 10 weight percent of 
the composite based on the elemental metal and a vanadium component in an 
amount from about 0.1 to about 10 weight percent of the composite based on 
the elemental metal, the carrier material comprising a co-gelled 
silica-alumina carrier material which comprises from about 20 weight 
percent to about 80 weight percent silica, which method comprises: (a) 
impregnating the co-gelled silica-alumina carrier material with an 
alcoholic solution of a vanadium compound and a nickel compound; and (b) 
calcining the resulting impregnated carrier material containing a nickel 
component and a vanadium component from step (a). 
Other embodiments of the present invention encompass further details such 
as specific concentrations of the catalytic composite, methods of 
preparation, preferred feedstocks, and hydrocracking conditions, all of 
which are hereinafter disclosed in the following discussion of each of 
these facets of the invention. 
DETAILED DESCRIPTION OF THE INVENTION 
The hydrocarbon charge stock subject to hydroconversion in accordance with 
the process of this invention is suitably a petroleum hydrocarbon fraction 
boiling in the range of from about 400.degree. F. to about 1200.degree. F. 
Pursuant to the present process, the hydrocarbon charge stock is reacted 
with an external source of hydrogen at hydroconversion conditions 
including a hydrogen pressure from about 500 psig to about 3,000 psig and 
a temperature of from about 500.degree. F. to about 900.degree. F. 
Petroleum hydrocarbon fractions which can be utilized as charge stocks thus 
include the gas oils, fuel oils, kerosene, etc., recovered as distillate 
in the atmospheric distillation of crude oils, also the light and heavy 
vacuum gas oils resulting from the vacuum distillation of the reduced 
crude, the light and heavy cycle oils recovered from the catalytic 
cracking process, light and heavy coker gas oils resulting from low 
pressure coking, coal tar distillates and the like. Residual oils, often 
referred to as asphaltum oil, liquid asphalt, black oil, residuum, etc., 
obtained as liquid or semi-liquid residues after the atmospheric or vacuum 
distillation of crude oils, are operable in this process although it may 
be desirable to blend such oils with lower boiling petroleum hydrocarbon 
fractions for economical operation. The petroleum hydrocarbon charge stock 
may boil substantially continuously between about 400.degree. F. to about 
1200.degree. F. or it may consist of any one, or a number of petroleum 
hydrocarbon fractions, such as are set out above, which distill over 
within the 400.degree.-1200.degree. F. range. Suitable hydrocarbon 
feedstocks also include hydrocarbons derived from tar sand and oil shale. 
Since the petroleum hydrocarbons and other hydrocarbons as well which are 
hydroprocessed according to the process of this invention boil over a 
considerably wide range, it may be readily perceived that suitable 
reaction temperatures will lie within a correspondingly wide range, the 
preferred temperature ranges depending in each instance upon the 
particular petroleum hydrocarbon fraction utilized as a charge stock. For 
example, reaction temperatures of from about 500.degree. to about 
1000.degree. F. are generally operable. However, where the particular 
petroleum hydrocarbon fraction utilized boils within the range of from 
about 700.degree. to about 900.degree. F., it is preferred to operate at 
reaction temperatures in the more restricted range of from about 
500.degree. to about 800.degree. F. 
Pursuant to the present invention and as hereinabove mentioned, an external 
source of hydrogen is reacted with the hydrocarbon charge stock at a 
pressure of from about 500 psig to about 3000 psig, and preferably at a 
pressure from about 1200 psig to about 2000 psig. The hydrogen circulation 
rate is preferably from about 2000 standard cubic feet to about 20,000 
standard cubic feet per barrel of charge stock, although amounts of from 
about 1,000 standard cubic feet to as much as 30,000 standard cubic feet 
per barrel are operable. The liquid hourly space velocity of the petroleum 
hydrocarbon charge stock is preferably from about 0.2 to about 10 
depending on the particular charge employed and the reaction temperatures 
necessitated thereby. A suitable correlation between space velocity and 
reaction temperature can be readily determined by one skilled in the art 
in any particular instance. When utilizing a charge stock boiling in the 
range of from about 700.degree. to about 900.degree. F., a liquid hourly 
space velocity of from about 1 to about 3 is preferred. 
In accordance with another embodiment of the present invention, further 
details of the catalyst, its specific concentrations and methods of 
preparation are hereinafter discussed. As is customary in the art of 
catalysis, when referring to the catalytically active metal, or metals, it 
is intended to encompass the existence of such metal in the elemental 
state or in some form such as an oxide, sulfide, halide, etc. Regardless 
of the state in which the metallic component actually exists, the 
concentrations are computed as if they existed in the elemental state. 
The silica-alumina carrier material which comprises a portion of the 
catalyst of the present invention may be prepared in any convenient manner 
known in the prior art. However, according to a preferred method of the 
present invention, the silica-alumina carrier material is co-gelled. The 
co-gelled silica-alumina may be prepared and utilized as spheres, pills, 
pellets, extrudates, granules, etc. In a preferred method of manufacture, 
an aqueous water glass solution, diluted to a silica concentration of from 
about 5 to about 15 wt.%, is acidified with hydrochloric acid or other 
suitable mineral acid. The resulting sol is acid aged at a pH of from 
about 4 to about 4.8 to form a hydrogel, and the hydrogel is further aged 
at a pH of from about 6.5 to about 7.5. The silica hydrogel is then 
thoroughly admixed with an aqueous aluminum salt solution of sufficient 
concentration to provide a desirable alumina content in the silica-alumina 
product. The silica-alumina sol is then precipitated at a pH of about 8 by 
the addition of a basic precipitating agent, suitably aqueous ammonium 
hydroxide. The silica-alumina, which exists as a hydrogel slurried in a 
mother liquor, is recovered by filtration, water-washed and dried at a 
temperature of from about 200.degree. to about 500.degree. F. Drying is 
preferably by spray-drying techniques whereby the co-gelled silica-alumina 
is recovered as microspheres, admixed with a suitable binding agent such 
as graphite, polyvinyl alcohol, etc., and extruded or otherwise compressed 
into pills or pellets or any other uniform size and shape. 
The particularly preferred method for preparing the co-gelled 
silica-alumina support is by the well-known oil drop method which permits 
the utilization of the support in the form of macrospheres. For example, 
an alumina sol, utilized as an alumina source, is commingled with an 
acidified water glass solution as a silica source, and the mixture further 
commingled with a suitable gelling agent, for example urea, 
hexamethylenetetramine, or mixtures thereof. The mixture is discharged 
while still below gelation temperature, and by means of a nozzle or 
rotating disc, into a hot oil bath maintained at gelation temperature. The 
mixing is dispersed into the oil bath as droplets which form into 
spheroidal gel particles during passage therethrough. The aluminum sol is 
preferably prepared by a method wherein aluminum pellets are commingled 
with a quantity of treated or deionized water, and hydrochloric acid added 
thereto in a sufficient amount to digest a portion of the aluminum metal 
and form the desired sol. A suitable reaction rate is effected at about 
reflux temperature of the mixture. 
The spheroidal gel particles prepared by the oil drop method are aged, 
usually in the oil bath, for a period of at least 10-16 hours, and then in 
a suitable alkaline or basic medium for at least 3 to about 10 hours, and 
finally water washed. Proper gelation of the mixture in the oil bath, as 
well as subsequent aging of the gel spheres, is not readily accomplished 
below about 120.degree. F., and at about 210.degree. F., the rapid 
evolution of the gases tend to rupture and otherwise weaken the spheres. 
By maintaining sufficient superatmospheric pressure during the forming and 
aging steps in order to maintain water in the liquid phase, a higher 
temperature can be employed, frequently with improved results. If the gel 
particles are aged at superatmospheric pressure, no alkaline aging step is 
required. 
The spheres are water-washed, preferably with water containing a small 
amount of ammonium hydroxide and/or ammonium nitrate. After washing, the 
spheres are dried, at a temperature from 200.degree. to about 600.degree. 
F. for a period of from about 6 to about 24 hours or more, and then 
calcined at a temperature from about 800.degree. to about 1400.degree. F. 
for a period from about 2 to about 12 hours or more. A preferred 
silica-alumina carrier material contains from about 20 weight percent to 
about 80 weight percent silica. 
In accordance with the present invention, the nickel component and the 
vanadium component are composited with the co-gelled silica-alumina 
carrier material as described hereinafter. The nickel component may be 
incorporated either before, after or simultaneously with the incorporation 
of the vanadium component. The nickel component may be composited with the 
co-gelled silica-alumina carrier material by any suitable solution 
impregnation technique. In the event that the nickel component is to be 
composited before the vanadium component, the carrier material containing 
nickel is dried and calcined before the incorporation of the vanadium 
component. Thus, for example, the carrier material may be soaked, dipped, 
suspended, or otherwise immersed in an aqueous impregnating solution 
containing a soluble nickel salt to effect the incorporation of the nickel 
component. One suitable method comprises immersing the carrier material in 
the nickel impregnating solution and evaporating the same to dryness in a 
rotary steam dryer The concentration of the impregnating solution is such 
as to ensure a final catalyst composite comprising from about 0.1 to about 
10 percent by weight nickel. A suitable nickel salt for impregnating the 
catalyst of the present invention is nickel nitrate. After the nickel 
component has been incorporated with the silica-alumina carrier material, 
the nickel containing carrier material is usually dried at a temperature 
from about 200.degree. F. to about 500.degree. F. for a period of time 
from about 1 to about 10 hours. The dried carrier material is then 
calcined in an oxidizing atmosphere at a temperature from about 
700.degree. to about 1300.degree. F. or more. The oxidizing atmosphere is 
suitably air, although other gases comprising molecular oxygen may be 
employed. Other convenient and suitable impregnation techniques may also 
be employed for the incorporation of the nickel component. 
Regardless of the incorporation techniques utilized, the order in which 
each nickel component or vanadium component is composited with the 
silica-alumina carrier material is not critical to the present invention. 
The silica-alumina carrier material is preferably dried and calcined after 
each metal component has been added to the carrier material. In the event 
that the vanadium component is to be composited before the nickel 
component, the carrier material containing vanadium is dried and calcined 
before the incorporation of the nickel component. In the event of 
co-impregnation of nickel and vanadium from an alcoholic solution thereof, 
a single calcination is sufficient. 
In accordance with the present invention, the vanadium component is 
composited with the silica-alumina carrier material by impregnating the 
carrier material with an alcoholic solution of a vanadium compound. 
Generally the compounds of vanadium are insoluble in water, thereby 
precluding the use of aqueous solutions of vanadium for catalyst 
preparation. The preferred solution is a methanol solution of vanadium 
chloride. Another preferred solution is a methanol solution of vanadium 
oxychloride. Since the solubility of vanadium chloride even in methanol is 
low, the incorporation may be more easily accomplished by the use of a 
technique which is similar to that used in the Sohxlet extractor method. 
In the event that the vanadium component is to be composited before the 
nickel component, the carrier material containing vanadium is preferably 
dried and calcined before contact is made with a nickel component. A 
preferred concentration of the vanadium component in the finished 
composite is from about 0.1 to about 10 weight percent based on elemental 
metal. 
After the silica-alumina carrier material has been incorporated with either 
one or both of the appropriate metals, the catalyst composite is usually 
dried at a temperature from about 200.degree. to about 500.degree. F. for 
a period of time from about 1 to about 10 hours prior to calcination. In 
accordance with the present invention, calcination is effected in an 
oxidizing atmosphere at a temperature from about 700.degree. to about 
1300.degree. F. or more. The oxidizing atmosphere is suitably air, 
although other gases comprising molecular oxygen may be employed. 
Without wishing to be bound by a theory, it is believed that the 
impregnation of the silica-alumina carrier material with a nickel compound 
and an alcoholic solution of a vanadium compound permits, in marked 
contradistinction with the hereinabove discussed inadvertently formulated 
nickel, vanadium and silica-alumina catalyst, a homogeneous deposition of 
the metal components throughout the catalyst particle while at the same 
time promoting a favorable interaction of the metal moieties with each 
other and with the silica-alumina carrier material and all of which is 
believed to contribute to the superior performance of the finished 
catalyst composite. 
Following the high temperature oxidation procedure, the catalyst is usually 
reduced for a period of from about 0.5 to about 10 hours at a temperature 
in the range of from about 700.degree. to about 1000.degree. F. in the 
presence of hydrogen. The catalyst as used in accordance with the present 
invention may be used in a sulfided form. Thus, after reduction the 
catalyst may be subjected to sulfidation by passing hydrogen sulfide, or 
other suitable sulfur-containing compounds, in contact therewith, 
preferably at an elevated temperature of from about 500.degree. to about 
1100.degree. F. The reduced catalyst is preferably sulfided by contacting 
the catalyst with a stream of hydrogen containing from about 1 to about 20 
percent or more by volume of hydrogen sulfide at elevated temperatures 
from about 500.degree. to about 1100.degree. F. When the petroleum 
hydrocarbon to be hydroconverted contains sulfur compounds, by design or 
otherwise, sulfidation may be suitably effected in situ in the initial 
stages of the hydroconversion process. 
The catalyst composite, prepared in accordance with the method of this 
invention may be employed in any type of a convenient reaction zone. 
However, in accordance with a preferred embodiment of the present 
invention, the catalyst is employed in a reaction zone as a fixed bed. The 
hydrocarbon charge stock after being combined with hydrogen in an amount 
of from about 2,000 to about 20,000 standard cubic feet per barrel, and 
preferably at least about 5,000 standard cubic feet per barrel, is 
introduced into the reaction zone. The charge stock may be in a liquid, 
vapor, or liquid-vapor phase mixture, depending upon the temperature, 
pressure, proportion of hydrogen and the boiling range of the charge stock 
being processed. As hereinabove described, the liquid hourly space 
velocity through the reaction zone will be in excess of about 0.1 and 
generally in the range of from about 0.5 to about 10. The source of 
hydrogen being admixed with a hydrocarbon charge stock may comprise a 
hydrogen-rich gas stream which is withdrawn from a high pressure, 
low-temperature separation zone and recycled to supply at least a portion 
of such hydrogen. Excess hydrogen resulting from the various 
dehydrogenation reactions effected in a catalytic reforming unit may also 
be employed in admixture with the hydrocarbon charge. In accordance with 
the present invention, an external source of hydrogen is required for the 
hydrocracking process. The reaction zone as hereinabove described will 
operate under an imposed pressure within the range of from about 500 to 
about 3,000 lbs. per square inch gauge (psig). The catalyst bed inlet 
temperature is maintained within the range of from about 350.degree. F. to 
about 800.degree. F. Since the hydroconversion reactions are exothermic, 
the outlet temperature or the temperature at the bottom of the catalyst 
bed will be significantly higher than that at the inlet thereto. The 
degree of exothermicity exhibited by the temperature rise across the 
catalyst bed is at least partially dependent upon the character of the 
charge stock passing therethrough, the rate at which the normally liquid 
hydrocarbon charge contacts the catalyst bed, the intended degree of 
conversion to lower-boiling hydrocarbon products, etc. In any event, the 
catalyst bed inlet temperature will be such that the exothermicity of the 
reactions taking place does not cause the temperature at the outlet of the 
bed to exceed about 900.degree. F., and preferably, 850.degree. F. The 
hydroconversion operation may also be effected as a moving-bed type, or 
suspensoid type of operation in which the catalyst, hydrocarbon and 
hydrogen are admixed and passed as a slurry through the reaction zone. 
Although the method of preparing the catalyst, and careful selection of 
operating condition within the ranges hereinbefore set forth, extend the 
effective life of the catalyst composite, regeneration thereof may 
eventually become desirable due to the natural deterioration of the 
catalytically active metallic components. The catalytic composite is 
readily regenerated by treating the same in an oxidizing atmosphere, at a 
temperature of from about 750.degree. F. to about 850.degree. F., and 
burning coke and other heavy hydrocarbonaceous material therefrom. The 
catalyst composite may then be subjected to the reducing action in 
hydrogen, in situ, at a temperature within the range of from about 
1000.degree. to about 1200.degree. F. If desirable, the catalyst may then 
be sulfided in the same manner as fresh catalyst as hereinbefore described 
.

The following examples are given to further illustrate the catalyst and 
hydrocarbon conversion process of the present invention. It is understood 
that these examples are to be illustrative rather than restrictive. 
Specific catalyst compositions, catalyst preparation techniques, 
processing techniques, processing conditions and other details are 
presented for description but it is not intended that the invention be 
limited to the specifics, nor is it intended that a given catalyst or 
process be limited to the particulars mentioned. 
EXAMPLE I 
This example describes the preparation and testing of a 
silica-alumina-nickel catalyst which comprises 0.6 weight percent nickel. 
The silica-alumina material was a co-gelled support material and was 
prepared by the hereinabove described oil-drop method. The ratio of silica 
and alumina sources was selected to yield a 50/50 mixture of silica and 
alumina. The finished silica-alumina support material was in the form of 
1/16 inch spheres and had an apparent bulk density of about 0.6. A portion 
of the hereinabove described silica-alumina carrier material was 
impregnated with an aqueous solution of nickel nitrate. The impregnated 
spheres were dried and then oxidized in air (calcined) at a temperature of 
1100.degree. F. The concentration of nickel nitrate solution was selected 
to yield a finished catalyst which contained 0.6 weight percent nickel. 
This batch of finished catalyst will hereinafter be referred to as 
Catalyst 1. Catalyst 1 was then used in the hydrocracking of a vacuum gas 
oil whose properties are summarized in Table I. 
TABLE I 
______________________________________ 
Properties of Vacuum Gas Oil 
API.degree. Gravity at 60.degree. F. 
21.6 
Specific Gravity at 60.degree. F. 
0.9242 
Distillation, .degree.F. 
IBP 441 
10 619 
30 705 
50 758 
70 805 
90 886 
E.P. 959 
Total Sulfur, wt. % 3.01 
Total Nitrogen, wt. % 
0.12 
Aromatics, Vol. % 56.4 
Paraffins and Naphthenes, vol. % 
43.6 
Pour Point, .degree.F. 
65 
______________________________________ 
The hereinabove described vacuum gas oil was processed in a small-scale 
pilot plant over a fixed bed of Catalyst 1 with a reactor pressure of 2000 
psig, a liquid hourly space velocity of 1.0, a hydrogen circulation rate 
of 12,000 SCFB and a reactor temperature of 760.degree. F. These test 
conditions define a standard relative activity test procedure whereby a 
relative activity number is calculated. The relative activity number is a 
comparison of the activity of an experimental catalyst with the activity 
of a standard commercial hydrocracking catalyst which activity is 
arbitrarily assigned a value of 100. In this case, the standard commercial 
hydrocracking catalyst was a silica-alumina based catalyst comprising 
nickel and tungsten and which catalyst as mentioned before was assigned to 
relative activity of 100. According to the standard test procedure, the 
Catalyst 1 demonstrated a relative activity of 24. The results of this 
example are summarized in Table II. From these results, Catalyst 1 is a 
poor candidate or prototype for a commercial hydrocracking catalyst. 
EXAMPLE II 
This example describes the preparation and testing of a 
silica-alumina-vanadium catalyst which comprises 2 weight percent 
vanadium. The silica-alumina material was a co-gelled support material and 
was prepared by the hereinabove described oil-drop method. The ratio of 
silica and alumina sources was selected to yield a 50/50 mixture of silica 
and alumina. The finished silica-alumina support material was in the form 
of 1/16 inch spheres and had an apparent bulk density of about 0.6. A 
portion of the hereinabove described silica-alumina carrier material was 
impregnated with a methanol solution of vanadium chloride (VCl.sub.3) 
using a Sohxlet extractor. After the vanadium component was incorporated, 
the methanol was removed in a rotary evaporator. The impregnated spheres 
were then oxidized in air (calcined) at a temperature of 1100.degree. F. 
The finished catalyst contained 2 weight percent vanadium. This batch of 
finished catalyst will hereinafter be referred to as Catalyst 2. Catalyst 
2 was then used in the hydrocracking of a vacuum gas oil having the 
properties as described in Table I. The hereinabove described vacuum gas 
oil was processed in the same pilot plant which was used in Example I over 
a fixed bed of Catalyst 2 utilizing the operating conditions of the 
standard relative activity test procedure as described in Example I. When 
Catalyst 2 was compared with the standard commercial hydrocracking 
catalyst selected and used in Example I, Catalyst 2 demonstrated a 
relative activity of 28. The results of this example are summarized in 
Table II. From these results, Catalyst 2 is also a poor candidate for a 
commercial hydrocracking catalyst. 
EXAMPLE III 
This example describes the preparation and testing of a 
silica-alumina-nickel-vanadium catalyst which comprised 2 weight percent 
vanadium and 0.6 weight percent nickel. This catalyst is a preferred 
embodiment of the present invention and was prepared and utilized in 
accordance with other preferred embodiments of the present invention. The 
silica-alumina material was a co-gelled support material and was prepared 
by the hereinabove described oil-drop method. The ratio of silica and 
alumina sources was selected to yield a 50/50 mixture of silica and 
alumina. The finished silica-alumina support material was in the form of 
1/16 inch spheres and had an apparent bulk density of about 0.6. A portion 
of the hereinabove described silica-alumina carrier material was 
impregnated with an aqueous solution of nickel nitrate. The impregnated 
spheres were dried and then oxidized in air (calcined) at a temperature of 
1100.degree. F. The resulting oxidized spheres were impregnated with a 
methanol solution of vanadium chloride (VCl.sub.3) using a Sohxlet 
extractor. After the vanadium component was incorporated, the methanol was 
removed in a rotary evaporator. The impregnated spheres were then oxidized 
at a temperature of 1100.degree. F. The finished catalyst contained 0.6 
weight percent nickel and 2 weight percent vanadium. This batch of 
finished catalyst will hereinafter be referred to as Catalyst 3. Catalyst 
3 was then used in the hydrocracking of a vacuum gas oil having the 
properties as described in Table I. The hereinabove described vacuum gas 
oil was processed in the same pilot plant which was used in the previous 
examples over a fixed bed of Catalyst 3 while utilizing the operating 
conditions of the standard relative activity test procedure as described 
in Example I. When Catalyst 3 was compared with the standard commercial 
hydrocracking catalyst selected and used in both earlier examples, 
Catalyst 3 demonstrated a relative activity of 62. The results of this 
example are summarized in Table II. From these results, it is readily 
apparent that a hydrocracking catalyst comprising silica and alumina and 
containing both a nickel component and a vanadium component exhibits 
unexpectedly good hydrocarbon conversion characteristics. 
Although the catalyst of the present invention which comprises nickel and 
vanadium on a silica-alumina carrier material demonstrated a relative 
activity of 62 and the commercial hydrocracking catalyst which was 
selected for comparison purposes had an assigned relative activity of 100, 
the utility of the catalyst of the present invention is not vitiated by 
such a comparison showing. For instance, in cases where a very high 
activity catalyst is not warranted, the catalyst of the present invention 
provides an attractive alternative catalyst. Also, in the event that 
tungsten becomes scarce or unavailable, or that the price of tungsten 
compared to that of vanadium dictates a substitute metal in a 
tungsten-containing catalyst, the catalyst of the present invention 
provides an attractive, or perhaps necessary, alternative. 
EXAMPLE IV 
This example describes the preparation and testing of a 
silica-alumina-nickel-vanadium catalyst which comprised 2 weight percent 
vanadium and 0.6 weight percent nickel. This catalyst is also a preferred 
embodiment of the present invention and was prepared and utilized in 
accordance with other preferred embodiments of the present invention. The 
silica-alumina material was a co-gelled support material and was prepared 
by the hereinabove described oil-drop method. The ratio of silica and 
alumina sources was selected to yield a 50/50 mixture of silica and 
alumina. The finished silica-alumina support material was in the form of 
1/16 inch spheres and had an apparent bulk density of about 0.6. A portion 
of the hereinabove described silica-alumina carrier material was 
impregnated with a methanol solution containing methanol, nickel chloride 
and vanadium oxychloride. After the vanadium and nickel components were 
incorporated, the methanol was removed in a rotary evaporator. The 
impregnated spheres were dried and then oxidized in air (calcined) at a 
temperature of 1100.degree. F. The finished catalyst contained 0.6 weight 
percent nickel and 2 weight percent vanadium. This batch of finished 
catalyst will hereinafter be referred to as Catalyst 4. Catalyst 4 was 
then used in the hydrocracking of a vacuum gas oil having the properties 
as described in Table I. The hereinabove described vacuum gas oil was 
processed in the same pilot plant which was used in the previous examples 
over a fixed bed of Catalyst 4 while utilizing the operating conditions of 
the standard relative activity test procedure as described in Example I. 
When Catalyst 4 was compared with the standard commercial hydrocracking 
catalyst selected and used in the earlier examples, Catalyst 4 
demonstrated a relative activity of 59. The results of this example are 
summarized in Table II. From these results, it is apparent that 
co-impregnation of the nickel component and the vanadium component with an 
alcoholic solution also provides a catalyst which exhibits unexpectedly 
good hydrocarbon conversion characteristics. 
TABLE II 
______________________________________ 
SUMMARY OF CATALYST TESTS 
Relative 
Catalyst 
Catalyst Composition Activity 
______________________________________ 
1 50/50 Silica-Alumina with 0.6% Nickel 
24 
2 50/50 Silica-Alumina with 2% Vanadium 
28 
3 50/50 Silica-Alumina with 0.6% Nickel 
62 
and 2% Vanadium 
(Sequential Impregnation) 
4 50/50 Silica-Alumina with 0.6% Nickel 
59 
and 2% Vanadium 
(Co-impregnation) 
______________________________________ 
The foregoing description and examples clearly illustrate the improvements 
encompassed by the present invention and the benefits to be afforded 
therefrom.