Note: Descriptions are shown in the official language in which they were submitted.
F-1584-L
SIMULTANEOUS CATALYTIC HYDROCRACKING AND
This invention relates to a pxocess ~or catalytically
hydrocracking and hydrodewaxing hydrocarbon charge stocks to produce
low pour point distillates and heavy fuel oils of reduced viscoslty.
Catalytic dewaxing of hydrocarbon oils to reduce the
temperature at which separation of waxy hydrocarbons occurs is a
known process. A process of that nature is described in The Oil and
Gas Journal dated January 6, 1~75, at pages 69-73~ Plso, U.S.
Patent 3,668,113 and U.S. Patent 3,8~4,938 describe dewaxing
followed by hydrofinishing.
Reissue Patent No. 28,398 describes a process for catalytic
dewaxing with a catalyst comprising a zeolite of the ZSM-5 type. A
hydrogenation~dehydrogenation component may be present.
A process for hydrodewaxing a gas oiI with a ZSM-5 type
catalyst is described in U.S. Patent 3,956,102.
A mordenite catalyst containing a Group VI or a Group VIII
metal is used to dewax a low V.I. distillate from a waxy crude, as
described in U.S. Patent 4,110,056.
U.S. Patent 3,7559138 describes a process for mild solvent
dewaxing to remove high quality wax from a lube stock, which is then
catalytically dewaxed to specificatio~ pour pointO
U.S. Patent 3,923,641 describes a process for hydrocracking
napthas using zeolite beta as a catalyst.
Hydrocracking is a well known process and various zeolite
catalysts have been employed in hydrocracking processes but although
they may be effective in providing distillate yields having one or
more properties consistent with the intended use of the distillate,
these catalysts have, in general, suffered the disadvantage of not
1584 L ~ ~ ~ t
~2~
providing product yields having good low temperature fluidity
characteristics, especially reduced pour point and viscosity. The
catalysts used for hydrocracking comprise an acid component and a
hydrogenation component. The hydrogerlation component may be a nobLe
s metal such as platinum or palladium or a non-noble metal such as
nickel, molybdenum or tungsten or a combination of these metals.
The acidic cracking component may be an amorphous material such as
an acidic clay or amorphous silica-alumina or, alternatively7 a
zeolite. Large pore zeolites such as zeolites X and Y have been
conventionally used for this purpose because the principal
components of the feedstocks (gas oils, coker bottoms, reduced
crudesj recycle oils, FCC bottoms) are higher molecular weight
hydrocarbons which will not enter the internal pore structure of the
smaller pore zeolites and therefore will not undergo conversion.
So, i~ waxy feedstocks such as~Pmal Gas nil are hydrocracked with a
large pore catalyst such as zeolite Y in combination with a
hydrogenation component, the viscosity of the oil is reduced by
cracking most of the 3~3C~ material into matPrial that boils at
343C to 165C. The remainder of the 343~C~ material that is not
converted contains the majority of the paraffinic components in the
feedstock because the aromatics are converted preferentially to the
paraffins. The unconverted 3~3C+ material therefore retains a high
pour point so that the final product will also have a relatively
high pour point of about lO~C. Thus, although the viscosity is
reduced, the pour point is still unacceptable. Even if the
conditions are adjusted to give complete or nearly complete
conversion, the higher molecular weight hydrocarbons~ which are
present in the feedstock, principally polycyclic aromatics, will be
subjected to cracking so as to lead to further reductions in the
viscosity of the product. The cracking products, however, will
include a substantial proportion oF straight chain components
(n-paraffins) which, if they are of sufficiently high molecular
F-1584-L ~ 3
weight themselves, as they often are, will constitute a waxy
component in the product. The final product may therefore be
proportionately more waxy than the feedstock and, consequently, may
have a pour point which is equally unsatisfactory or even more so.
A further disadvantage of operating under high conversion conditions
is that the consumption of hydrogen is increased. Attempts to
reduce the molecular weight o~ these straight chain paraffinic
products will only serve to produce very light fractions for
example7 propane, so decreasing the desired liquid yield.
In the dewaxing process, on the other hand, a small pore
zeolite or a shape selective zeolite such as ZSM-5 is used as the
acidic component of the catalyst and the normal and slightly
branched chain parafFins which are present in the feedstock will be
able to enter the internal pore structure of the zeolite so that
they will undergo conversion. The major proportion -- typically
about 70 percent of the feedstock - boiling above 343C will remain
unconverted because th0 bulky aromatic components, especially the
polycyclic arnmatics, are unable to enter the zeolite. The
paraffinic waxy components will therefore be removed so as to lower
the pour point of the product but the other components will remain
so that the final product will have an unacceptably high viscosity
even though the pour point may be satisfactory.
It has now been found that heavy hydrocarbon oils may be
simultaneously hydrocracked and hydrodPwaxed to produce a liquid
product of satisfactory pour point and viscosity. This desirable
result is obtained by the use o~ a catalyst which contains zeolite
beta as an acidic component to induce the cracking reactions~ The
catalyst preferably includes a hydrogenation component to induce
hydrogenation reactions. The hydrogenation component may be a noble
metal or a non-noble metal and is suitably of a conventional type,
for example nic~el, tungsten, cobalt, molybdenum or combinations of
these metals.
F 15~4~ r~t
--4~
In accordance with the inventlon, there is provided a
process for cracking and dewaxing a heavy hydrocarbon oil which
comprises contacting the oil with a catalyst comprising zeolite beta.
In the process o~ the invention, the hydrocarbon ~eedstock
is heated with the catalyst under conversion conditions which are
appropriate for hydrocracking. During the conversion, the aromatics
and naphthenes which are present in the ~eedstock undergo
hydrocracking reactions such as dealkylation, ring opening and
crac~ing, ~ollowed by hydrogenation. The long chain para~ins which
are present in the ~eedstock, together with the para~ins produced
by ~he hydrocxacking o~ the aromatics are~ in additionl converted
into products which are less waxy than the straight chain
n-para~fins, thereby ef~ecting a simultaneous dewaxing. The use of
zeolite beta is believed to be unique in this respect, produciny not
only a reduction in the viscosity o~ the product by hydrocracking
but also a simultaneous reduction in pour point by catalytic
hydrodewaxing.
The process enables heavy ~eedstocks such as gas oils
boiling above 343C to be converted to distillate range products
boiling below 343C but in contrast to prior processes using large
- pore catalysts such as zeolite Y, the consumption o~ hydrogen will
be reduced even though the product will con~orm to the desired
specifications for pour point and viscosity~ In contrast to
dewaxing processes using shape selective catalysts such as zeolite
ZSM-5, the bulk conversion including cracking o~ aromatic components
takes place, ensuring asceptably low viscosity in the distillate
range product. Thus, the present process is capable o~ ef~ecting a
bulk conversion together with a simultaneous dewaxing~ Moreover~
this is achieved with a reduced hydrogen consumption as compared to
the other types o~ process. It is also possible to operate at
partial conversion~ thus e~fecting economies in hydrogen consumption
while still meeting pour point and viscosity requirements. The
F-15B4-L
-5-
process also achieves enhanced selectivity for the production of
distillate range materials; the yield of gas and products boiling
below the distillate range is reduced.
As mentioned above, the process combines elements of
hydrocracking and dewaxing. The catalyst used in the process has an
acidic component and a hydrogenation component which may be
conventional in type. The acidic component comprises zeolite beta,
which is described in U.S. Patents 3~3039069 and Re 28,~41 and
reference is made to those patents for details of this zeolite and
its preparation.
Zeolite beta is a crystalline aluminosilicate zeolite
having a pore size greater than 5 Angstroms. The compositîon of the
zeolite as described in U.SO Patents 3,3û3aO69 and Re 28,~417 in its
as synthesized form may be expressed as follows:
[XNa(l.O~ X~TEA~Al02.YSiO20WH20
where X is less than 1, preferably less than 0.7; TEA represents the
tetraethylammonium ion; Y is greater than 5 but less than 100 and W
is up to about 60 (it has been found that the degree of hydration
may be hiyher than or.iginally determined, where W was defined as
being up to 4), depending on the degree of hydration and the metal
cation present~ The TEA component is calculated by differences from
the analyzed value of sodium and the theoretical
cation-to-structural aluminum ratio of unity.
In the fully base-exchanged form, beta has the composition:
~ (L~D.l-x)H].Alo2.ysio2.wH2o
where X, Y and W have the values listed above and n is the valence
o~ the metal M.
F-1584~L
In the partly base-exchanged form which is obtained ~rom
the initial sodium form of the zeolite by ion exchange without
calcining, zeolite beta has the for~ula:
~ M(~D.l-X)TEA]A102.YSiO2.WH20
When it is used in th catalysts, the zeolite is at least
partly in the hydrogen form in order to provide the desired acidic
functionality for the cracking reactions which are to take place.
It is normally pre~erred to use the zeolite in a form which has
sufficient acidic ~unctionality to give it an alpha value of 1 or
more. The alpha value, a measure o~ zeolite acidic functionality7
is described, together with details of its measurement in U.S.
Patent 4,016,218 and in J. Catalysis, Vol. VI, pages 278-287 (1966)
and reference is made to those publications for such details. The
acidic ~unctionality may be controlled by base exchange of the
zeolite, especially with alkali metal cations such as sodium, by
steaming or by control of the silica:alumina ratio of the zeolite.
When synthesized in the alkali metal form, zeolite beta may
be converted to the hydrogen form by formation of the intermediate
am~onium form as a result o~ ammonium ion exchange and calcination
of the ammunium form to yield the hydrogen ~oEm. In addition to tha
hydrogen ~orm, other forms o~ the zeolite wherein the original
alkali metal has been reduced to less than about 1.5 percent by
weight may be used. Thus, the original alkali metal of the zeolite
may be replaced by ion exchange with other suitable metal cations
including, by way of example, nickel, copper, zinc, palladium,
calcium and rare earth metals.
Zeolite betaS in addition to possessing a composition as
defined above, may also be characterized by its X-ray diffraction
data which are set out in U.S. Patents 3,308,069 and Re. 28,341.
The significant d values (Angstroms, xadiation: K alpha doublet o~
copper, Geiger counter spectrometer) are as shown in Table 1 below:
F-1584-L
-7-
TABLE 1
d Values of Reflections in Zeolite ~eta
11.40 -~ 0.2
7.~ 0.2
6~70 ~ 0.2
4.25 + 0.1
3.97 ~ û.l
3.00 ~ 0.1
2.20 ~ 0.1
The preferred forms of 7eolite beta for use in the process are the
high silica forms, having a silica:alumina ratio o~ at least ~0:1.
It has been found, in fact, that zeolite beta may be prepared with
silica:alumina ratios above the 100:1 maximum specified in U.S.
Patents 3,~08,069 and Re. ~8~341 and these forms of the zeolite
provide the best performance in the process. Ratios of at least
50:1 and preferably at least 100:1 or even higher, ~or example e.g.
250:1, 500:1 may be used.
The silica:alumina ratios referred to herein are the
structural or framework ratiosl that is, the ratio of the SiO4 to
the A104 tetrahedra which together constitute the structure of
which the zeolite is composed. It should be understood that this
ratio may vary from the silica:alumina ratio determined by various
physical and chemical methods. For example; a gross chemical
analysis may include aluminum which is present in the form of
cations associated with the acidic sites on the zeolite, thereby
giving a low silicaoalumina ratio. Similarly, if the ratio is
determined by the thermogravimetric analysis (TGA) of ammonia
desorption, a low ammonia titration may be obtained i~ cationic
aluminum prevents exchange of the ammonium ions onto the acidic
sites. These disparities are particularly troublesome when certain
treatments such as the dealuminization method described below, which
F-158~-L
result in the presence of ioni.c aluminum free of the zeolite
structure, are employedO Due care should therefore be taken to
ensure that the framework silica:alumina ratio is correctly
determined.
The silica:alumina ratio of the zeolite may be determined
by the nature of the starting materials used in its preparation and
their quantities relative one to another. Some variation in the
ratio may therefore be obtained by changing the relative
concentration of the silica precursor relative to the alumina
precursor but definite limits in the maximum obtainable
silica:alumina ratio of the zeolite may be observed. For zeolite
beta this limit is usually about 100:1 (although higher ratios may
be obtained) and for ratios above this value, other methods are
usually necessary for preparing the desired high silica zeolite.
One such method comprises dealumination by extraction with acid and
that method comprises contacting the zeolite with an acid,
preferably a mineral acid such as hydrochloric acid. The
dealuminization proceeds readily at ambient and mildly elevated
temperatures and occurs with minimal losses in crystallinity, to
form high silica forms of zeolite beta with silica:alumina ratios of
at least 100.1, with ratios of 200:1 or even higher being readily
attainable.
The zeolite is conveniently used in the hydrogen form for
the dealuminization process although other cationic forms may also
be employed, for example, the sodium form. If these other forms are
used, sufficient acid should be employed to allow for the
replacement by protons of the original cations in the zeolite. The
amount of zeolite in the zeoloite/acid mixture should generally be
from 5 to 60 percent by weight.
The acid may be a mineral acid, i.e.~ an inorganic acid or
an organic acid. Typical inorganic acids which can be employed
include mineral acids such as hydrochloric, sulfuric, nitric and
F~1584-L
_g .
phosphoric acids, peroxydisulfonic acid, dikhionic acid, sul~amic
acid, peroxymonosulfuric acid, amidodisulfonic acid, nitrosulfon~c
acid, chlorosulfuric acid, pyrosulfuric acid, and nitrous acid.
Representative organic acids which may be used include formic acid,
trichloroacetic acid, and trifluoroacetic acid.
The concentration of added acid should be such as not to
lower the pH of the reaction mixture to an undesirably low level
which could affect the crystallinity of the zeolite undergoing
treatment. The acidity which the zeolite can tolerate will depend,
at least in part, upon the silica/alumina ratio of the starting
material. ~enerally, it has been found that zeolite beta can
withstand concentrated acid without undue loss in crystallinity but
as a general guide, the acid will be from 0~1 N to 4.0 N, usually 1
to 2 N. These values hold good regardless of the silica alumina
ratio o~ the zeolite beta starting material. Stronger acids tend to
effect a relatiYely greater degree of aluminum removal than weaker
acids.
The dealuminization reaction proceeds readily at ambient
temperatures but mildly elevated temperatures may be employed e.g.
up to 100C. The duration of the extraction will affect the
siIioa:alumina ratio of the product since extraction~ being
di~fusion controlled, is time dependent. However, because the
zeolite becomes progressively more resistant ~o loss of
crystallinity as the silica:alumina ratio incr~ases i.e. it becomes
more stable as the aluminum is removedg higher temperatures and more
concentrated acids may be used towards the end of the treatment than
at the beginning without the attendant risk o~ losing crystallinity.
After the extraction treatment, the product is water-washed
free of impurities, preferably with distilled water, until the
effluent wash water has a pH within the approximate range o~ 5 to 8.
F 1584-L
-10--
The crystalline dealuminized products obtained by the
method of this invention have substantially the same
crystallographic structure as that of the starting aluminosilicate
zeolite but with increased silica:alumina ratios. The ~ormula o~
the dealuminized zeolite beta will therefore be
[~ (L~D.l-X)H]Al02-ysio2-wH2o
where X is less than 1, preferably less than 0.75, Y is at least
100, preferably at least 150 and W is up to 60. M is a metal,
preferably a transition metal or a metal o~ Groups IA, 2A or 3A, or
a mixture of metals. The silica:alumina ratio, Y, will generally be
in the range of 100:1 to 500:1, more usually 150:1 to 300:1, for
example 200:1 or morea The X-ray dif~raction patte m o~ the
dealuminized zeolite will be substantially the same as that of the
original zeolite, as set out in Table 1 above.
If desired, the zeolite may be steamed prior to acid
extraction so as to increase the silica:alumina xatio and render the
zeolite more stable to the acid. The steaming may also serve to
increase the ease with which the acid is removed and to promote the
retention of crystallinity during the extraction procedure.
The zeolite beta is preferably used in combination with a
hydrogenating component which is usually derived ~rom a metal of
Groups VA, VIA or VI~IA of the Feriodic Table. Pre~erred non-noble
metals are such as tungsten, vanadium, molybdenum, nickel, cobalt,
chromium, and manganese, and the preferrred noble metals are
platinum, palladium9 iridium and rhodium. Oombinations of non-noble
metals such as cobalt~olybdenum9 cobalt nickel, nickel-tungsten or
cobalt-nickel-tungsten are exceptionally useful with many feedstocks
and, in a preferred combination, the hydrogenation component
comprises from 0.7 to about 7 wt.% nickel and 2.1 to about 21 wt.%
tungsten, expressed as metal. The hydrogenatîon component can be
exchanged onto the zeolite, impregnated into it or physically
F-15~4~L
admixed with it. If the metal is to be impregnated into or
exchanged onto the zeolite, it may be done, for example, by treating
the zeolite with a platinum metal-containing ion. Suitable platinum
compounds include chloroplatinic acid, platinous chloride and
various compounds containing the platinum ammine complex.
The catalyst may be treated by conventional pre-sulfiding
treatments, ~or example by heating in the presence of hydrogen
sul~ide, to convert oxide forms of the metals such as CoO or NiO to
their corresponding sulfides.
The metal compounds may be either compounds in which the
metal is present in the cation of the compound and compounds in
which it is present in the anion of the compound~ Both types o~
compounds can be used. Platinum compounds in which the metal is in
the form o~ a cation or cationic complex, for example,
Pt(NH3)4C12, are particularly useful, as are anionic complexes
such as the vanadate and metatungstate ions. Cationic forms o~
other metals are also very useful since they may be exchanged onto
the zeolite or impregnated into it~
Prior to use the zeolite should be dehydrated at least
partially. This can be done by heating to a temperature in the
range of 200C to 600C in air or an inert atmosphere such as
nitrogen ~or 1 to 48 hours. Dehydration can also be performed at
lower temperatures merely by using a vacuum, but a longer time is
required to obtain a suf~icient amount of dehydration.
It may be desirable to incorporate the catalyst in another
material resistant to the temperature and other conditions employed
in the process. Such matrix materials include synthetic and
naturally occurring substances such as inorganic materials, for
example clay, silica and metal oxides. The latter may be either
naturally occurring or in the form of gelatinous precipitates or
gels including mixtures of silica and metal oxides. Naturally
occurring clays can be composited with the zeolite including those
F~1584-L v~.3~ 3
12-
of the montmorillonike and kaolin ~amilies. The clays can be used
in the raw state as originally mined or initially subjected to
calcination, acid treatment or chemical modificatiun.
The zeolite may be composited with a porous matrix
material, such as alumina, silica-alumina, silica-magnesia,
silica-zirconia, silica-thoria, silica~berylia, silica-titania, as
well as terniary compositions, such as silica-alumina-thoria,
silica-alumina-zirconia, magnesia and silica-magnesia~zirconia. The
matrix may be in the form of a cogel. The relative proportions of
zeolite component and inorganic oxide gel matrix on an anhydrous
basis may vary widely with the zeolite content ranging from 10 to
99, more usually ~5 to 80, percent by weight o~ the dry composite.
The matrix itself may possess catalytic properties, generally of an
acidic nature.
The feedstock ~or the process of the invention comprises a
heavy hydrocarbon oil such as a gas oil, coker tower bottoms
fraction, reduced crude, vacuum tower bottoms; deasphalted vacuum
resids, FCC tower bottoms, or cycle oils. Oils derived ~rom coal,
shale, or tar sands may also be treated in this way. Oils of this
kind generally boil above 343C although the process is also use~ul
with oils which nave initial boiling points as low as 260~C. These
heavy oils comprise high molecular weight long chain paraffins and
high molecular weight aromatics with à large proportion of fused
ring aromatics. During the processingt the fused ring aromatics and
naphthenes are cracked by the acidic catalyst and the paraf~inic
cracking products, together with para~finic components of the
initial feedstock undergo conversinn to iso-paraffins with some
cracking to lower molecular weight materials. Hydrogenation of
unsaturated side chains on the monocyclic cracking residues of the
original polycyclics is catalyzed by the hydrogenation component to
form substituted monocyclic aromatics which are highly desirable end
products. The heavy hydrocarbon oil feedstock will normally contain
F 1584-L
-13-
a substantial amount boiling above 230C and will normally have an
initial boiling point of` about 290C3 more usually about 340C~
Typical boiling ran9es will be about 340 to 565C or about 340C to
510C but oils with a narrower boiling range may, of course, be
processed, For example, those with a boiling range of about 340 to
455C. Heavy gas oils are often of this kind as are cycle oils and
other non-residual materials. It is possible to co-process
materials boiling below 260C but the degree of conversion will be
lower for such components. Feedstocks containing lighter ends of
this kind will normally have an initial boiling point above 150C.
The process is of particular utility with highly paraffinic
feeds because, with feeds of this kind9 the greatest improvement in
pour point may be obtained. However, most feeds will contain a
certain content of polycyclic aromatics.
The process is carried out under conditions similar to
those used for conventional hydrocracking although the use of the
highly siliceous zeolite catalyst permits the total pressure
requirements to be reduced. Process temperatures of 230C to 500C
may conveniently be used although temperatures above 4250 will
20 normally not be employed as the thermodynamics of the hydrocracking
reactions become unfavorable at temperatures above this point.
Generally, temperatures of 300C to 4~5C will be employed. Total
pressure is usually in the range of 500 to 20,000 kPa and the higher
pressures within this range over 7000 kPa will normally be
25 preferred. The process is operated in the presence of hydrogen and
hydrogen partial pressures will normally be from 600 to 6000 kPa.
The ratio of hydrogen to the hydrocarbon feedstock (hydrogen
circulation rate) will normally be from 10 to 3500 n.l~l 1. The
space velocity of the feedstock will normally be from 0.1 to 20
30 LHSV, preferably 0.1 to 10 LHSV. At low conversions, the
n paraffins in the feedstock will be converted in preference to the
iso-paraffins but at higher conversions under more severe conditions
F-1584-L
the iso-paraffins will also be converted. The product is low in
fractions boiling below 150C and in most cases the product will
have a boiling range of 150 to 340C.
The conversion may be carried out by contacting the
feedstock with a fixed stationary bed of catalyst, a fixed fluidized
bed or with a transport ~ed. ~ simple configuration is a
trickle-bed operation in which the feed is allowed to trickle
through a stationary fixed bed. With such a configuration, it is
desirable to initiate the reaction with fresh catalyst at a moderate
temperature which is of course raised as the catalyst ages, in order
to maintain catalytic activity. The cata~yst may be regenerated by
contact at elevated temperature with hydroyen gas, for example, or
by burning in air or other oxygen-containing gas.
A preliminary hydrotreating step to remove nitrogen and
sulfur and to saturate aromatics to naphthenes without substantial
boiling range conversion will usually improve catalyst performance
and permit lower temperatures, higher space velocities, lower
pressures or combinations of these conditions to be employed.
The process of the invention is illustrated by the
following Examples. All parts and proportions in these Examples are
by weight unless stated to the contrary.
EXAMPLE 1
This Example illustrates the preparation of a catalyst.
A mixture of zeolite beta (SiO2/A1203=30) having a
crystallite size of less than 0.05 microns and an equal amount gamma
alumina on an anhydrous basis was extruded to form 1.5 mm. pellets.
The pellets were calcined at 540C in nitrogen, magnesium exchanged,
and then calcined in air.
One hundred grams of the air-calcined extrudate was
impregnated with 13.4 grams of ammonium metatungstate (72.3%W~ in 60
ml of water, followed by drying at 115C and calcination in air at 540c.
The extrudate was then impregnated with 15.1 grams of nickel nitrate
~--1S~4~
~5-
hexahydrate in 60 ml of waterl and the wet pellets dried and
calcined at 540C.
The final catalyst had a nickel content o~ about 4 weight
percent as NiO and a calculated tungsten content of about 10.0
weight percent as W03. The sodium content was less than 0.5
weight percent as sodium oxide.
~e~
This example describes the preparation of high silica
zeolite beta.
A sample of zeolite beta in its as-synthesiæed form and
having a silica:alumina ratio o~ 30:1 was calcined in flowing
nitrogen at 500C for 4 hours7 ~ollowed by air at the same
temperature for 5 hours. The calcined zeolite was then refluxed
with 2N hydrochloric acid at 95C for one hour to produce a
dealuminized, hiqh silica form of zeolite beta having a
silica:alumina ratio of 280:1, an alpha value of 20 and a
crystallinity of 80 percent relative to the original9 assumed to be
100 percent crystalline.
The zeolite was exchanged to the ammonium form with 1 N
ammonium chloride solution at 90C reflux for an hour followed by
the exchange with 1 N magnesium chloride solution at 90C reflux for
an hour. Platinum was introduced into the zeolite by ion-exchange
of the tetrammine complex at room temperature. The metal exchanged
zeolite was thoroughly washed and oven dried by air calcinatinn at
350C for 2 hours. The ~inished catalyst contained 0.6 percent
platinum and was pelletted, crushed and sized to 0.35 to 0.5 mm.
EXAMPLES 3 5
The catalyst of Example 1 was evaluated for the catalytic
conversion of an Arab Light gas oil (HVGO) having a boiling range of
354 to 580C. For comparison, a magnesium exchanged zeolite Y
(SiO2/~1203=5) catalyst was also composed by extrusion with an
equal amount of gamma alumina and impregnation to contain 4 weight
percent nickel and 10 weight percent tungsten.
F-1584-L
-16~
The feedstock composition, conditions used and product
analysis are given in rable ~ below.
TABLE 2
~c~9~
~ e~ Feed 3 4
Catalyst - Mg Beta MgY
Conditions:
423 414
Pressure, kPa ~ 7000 7000
LHSV, hr~l _ 0.54 0.71
H2, n.l.l.-l - 1674 1318
H2 Consumption, n.l.l-l 125 193
343~C + Conversion, wt. % - 62.2 56.6
Dry Gas ~ C4 3.5 4.1
C5 ~ 165C Naptha, wt. % - 16.6 24.7
165C - ~3C Distillate, wt. ~ - 40.6 26.3
343C + w~. ~ 10~ 37.8 44.0
343C ~ Pour Point, C 40 -1 35
343nc + 95% TBP7 C 552 468 528
343C+ Properties:
GraYity, API 22.0
Hydrogen, Wt.~ 12.Q7 12.7 13.7
Sulfur 2.45 Ø04 0.03
Nitrogen 60Q 80 18
Pour Point C 40 -1 35
Paxaf~ins, vol.~ 24.0 31 40
I Naphthenes, vol. % 25.3 28 35
Aromatics, vol.~ 50.7 41 25
As shown above in Table 2, at a relatively high conversion
of approximately 60 percent, the beta catalyst significantly lowered
the pour point of the 343C+ product whereas the products obtained
with zeolite Y catalysts remalned waxy. Additionally3 the beta
catalyst converted considerably more of the high boiling components
in the charge which resulted in a 343C+ product endpoint about 55C
F-15~4-L ll~ C~
~17-
lower than obtained with the catalyst of Example 4. The hydrogen
consumption was also notably lower whether on an a~solute basis or
relative to conversion.
For comparison with Example 3, a similar Arab Light HV~0
having a boiling range of 370 to 550~C was hydrocracked over a rare
earth exchanged ultrastable zeolite Y (SiO2:A120~ = 75). The
zeolite was prepared by steam calcination and acid dealuminization
of zeolite Y to a framework SiO2.A1203 ratio of 75.1, followed
by rare earth exchange, extrusion with an equal amount of gamma
alumina and impregnation to contain 2 weight percent nickel and 7
weight percent tungsten.
The feedstock composition, conditions used and product
analysis are given in Table 3 below.
F-1584-L
TA9LE 3
~e~
Feed 5
Conditions:
_ ~16
Pressure, kPa - 7000
LHSV, hr~l - 0.67
H2, n.l.l.-l 1338
H~ Consumptionl n.l.l~l 143
3~3C ~ Conversion, wt. % - 60.4
~e~
Dry Gas ~ C4 - 3.6
C5 - 165C Naptha, wt. % - 14.2
165C - 343C Distillate, wt. % - ~1.4
343C ~ wt. % 100 3~.6
343C + Pour Point, C 43 32
343C + 95~ TBP7 ~C 540 504
343qC~ Properti s:
Gravity, ~API 21.7 --
Hydrogen, Wt.% 12.17 13.26
Sul~ur 2.41 0.01
Nitrogen 550 ; 33
Pour Point C 43 32
Yields:
Paraf~îns, vol.~ 19 41
Naphthenes, vol. % 27 26
Aromaticsg vol.% 54 33
