Note: Descriptions are shown in the official language in which they were submitted.
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T 9005
HYDROCARBON CONVERSION CATALYSTS
The present invention relates to compositions of matter
suitable as catalyst base. in hydroprocessing. The present lnvention
also relates to catalyst compositions which can suitably be used in
hydrocarbon conversion processes, in particular hydrocracking
5 processes, and hydrocarbon conversion processes wherein use is made
of such catalyst compositions.
Of the many hydroconversion processes known in the art,
hydrocracking is becoming increasingly important since it offers
product flexibility together with product quality. As it is also
10 possible to subjact rather heavy feedstocks to hydrocracking it
will be clear that much attention has been devoted to the
development of hydrocracking catalysts.
Whereas in the past catalytic hydrocracking was aimed
primarily at the production of lower boiling points products such
15 as gasoline, nowadays hydrocracking is often aimed at meeting the
increasing demand for high quality middle distillate products.
Therefore, the object in nowadays hydrocracking is to provide
a hydrocracking catalyst having a high selectivity towards middle
distillates and in addition a high activity and stability.
To this end modern hydrocracking catalysts are generally based
on zeolitic materials which may have been adapted by techniques
like a~Monium-ion exchange and various forms of calcination in
order to improve the performance of the hydrocracking catalysts
based on such zeolitic materials.
One of the zeolites which is considered to be a good starting
material for the manufacture of hydrocracking catalysts is the
well-known synthetic zeolite Y as described in US-A-3,130,007. a
number of modifications has been reported for this material which
include, inter alia, ultrastable Y (US-A-3,536,605) and
30 ultrahydrophobic Y (GB-A-2,014,970). In general, it can be said
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that the modifications cause a reduction in the unit cell size
depending on the treatment carried out.
In EP-B-247679 compositions of matter have been described
which can very attractively be used as components for hydrocracking
catalysts
Surprisingly, it has now been found that even more attractive
results can be obtained in terms of gas make and middle distillate
yield when use is made of a composition comprising a binder and a
modified Y zeolite having a specific infrared feature.
Accordingly, the present invention relates to a composition of
matter suitable as catalyst base in hydroprocessing comprising a
crystalline aluminosilicate and a binder wherein the crystalline
aluminosilicate comprises a modified Y zeolite having a unit cell
size below 24.37 A, a water adsorption capacity (at 25 C and a
p/pO value of 0.2) of at least 8% by weight of modified Y zeolite,
a pore volume of at least 0.25 ml/g wherein between 10% and 60~ of
the total pore volume is made up of pores having a diameter of at
least 8 nm, which modified Y zeolite has an absorbance ratio of at
most 0.040, expressed as the absorbance in the infra-red frequency
region of 3670 + 10 cm divided by the absorbance in the infra-red
frequency region of 3630 ~ 10 cm 1
Preferably, the absorbance ratio is at most 0.03, more
preferably at most 0.02.
The infrared bands have been determined by means of in-situ
cell measurements of dry samples at elevated temperature (450C).
Preferably, the modified Y zeolite has a unit cell size
ranging from 24.27 to 24.35 A, more preferably from 24.29 to
24.33 A.
Preferably, between 10~ and 40~ of the total pore volume of
the modified Y zeolite is made up of pores having a diamster of at
least 8 nm.
Suitably, the modified Y zeolite has a water adsorption
capacity of 8-12~ by weight of modified zeolite.
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The pore diameter distribution and the water adsorption
capacity can suitably be determined by the methods as described in
EP-B-247679, which is herein incorporated by reference.
Preferably, the modified Y zeo:Lite has a SiO2/A1203 molar
ratio of from 4 to 25, more preferably of from 8 to 15.
The compositions of matter according to the present invention
suitably comprise 5-90% by weight of modified Y zeolite and 10-95%
by weight of binder. In a particular embodiment the compositions of
matter comprise rather high amounts of modified Y zeolite: 50-85%
by weight of modified Y zeolite and 15-50% by weight of binder
being preferred.
Suitably, the compositions of matter according to the present
invention comprise in addition an amorphous cracking component.
Suitably, such a composition of matter comprises 50-90% by weight
of modified Y zeolite and amorphous cracking component and 10-50
by weight of binder, preferably 60-85~ by weight of modified Y
zeolite and amorphous cracking component and 15-40~ by weight of
binder. Suitably, the amount of modified Y zeolite ranges between 5
and 95%, preferably between 10 and 75%, of the combined amo~mt of
modified Y zeolite and amorphous cracking component. Suitably,
silica-based amorphous cracking components can be used. Preference
is given to silica-alumina as amorphous cracking component. In
another embodiment use can be made of a dispersion of
silica-alumina in an alumina matrix as amorphous cracking
component. When use is made of such an amorphous cracking component
the composition of matter according to the present invention
suitably comprises less than 25% by weight of the modified Y
zeolite, more than 25~ by weight of binder and in addition at least
30% by weight of the dispersion of silica-alumina in an alumina
matrix.
Suitably, the composition of matter comprises at least 30% by
weight of binder.
Preference is given to compositions of matter comprising less
than 15% by weight of the modified ~ zeolite.
Preferably, the composition of matter has a binder/modified Y
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zeolite weight ratio in the range of 2-40.
Suitably, the composition of matter comprises 40-70~ by weight
of the dispersion.
Suitably, the alumina matrix comprises a transitional alumina
matrix, preferably a gamma-alumina matrix.
The binder(s) present in the compositions of matter according
to the present invention suitably comprise an inorganic oxide or a
mixture of inorganic oxides. Both amorphous and crystalline binders
can be applied. Examples of suitable binders comprise alumina,
0 magnesia, titania and clays. If desired, small amounts of other
inorganic oxides such as zirconia, titania, magnesia and silica may
be present. Alumina is a preferred binder. Suitably, the modified Y
zeolite has a degree of crystallinity which is at least retained at
increasing SiO2/Al203 molar ratios (relative to a certain standard,
e.g. Na-Y). Generally, the crystallinity will slightly improve when
comparing modified Y zeolites with increasing SiO2/Al203 molar
ratios.
The present invention further relates to a catalyst
composition comprising in addition to the composition of matter as
defined hereinbefore at least one hydrogenation component of a
Group VI metal and/or at least one hydrogenation component of a
Group VIII metal. Suitably, the catalyst composition according to
the present invention comprises one or more components of nickel
and/or cobalt and one or more components of molybdenum and/or
tungstsn or one or more components of platinum and/or palladium.
The amount(s) of hydrogenation component(s) in the catalyst
composition suitably ranges between Q.05 and 10% by weight of
Group VIII metal component(s) and between 2 and 40~ by weight of
Group VI metal component(s), calculated as metal(s) per 100 parts
by weight of total catalyst. The hydrogenation components in the
catalyst composition may be in the oxidic and/or sulphidic form, in
particular in the sulphidic form. If a combination of at least a
Group VI and a Group VIII metal component is present as (mixed)
oxides, it will normally be subjected to a sulphiding treatment
prior to proper use in hydrocracking.
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The compositions of matter in accordance with the present
invention are particularly useful in certain hydroconversion
processes, in particular hydrocracking processes.
The present invention, therefore, also relates to a process
for converting hydrocarbon oils into products of lower average
molecular weight and lower average boiling point comprising
contacting a hydrocarbon oil at elevated temperature and pressure
in the presence of hydrogen with a catalyst composition as
described hereinbefore.
Suitable process conditions for the hydroconversion process
comprise temperatures between 250 and 500 C, partial hydrogen
pressures of up to 300 bar and space velocities between 0.1 and
10 kg feed per litre catalyst per hour (kg/l/hr). Gas/feed ratios
between 100 and 5000 Nl/kg can suitably be applied. Preferably, the
hydroconversion process is carried out at a temperature between 300
and 450 C, a partial hydrogen pressure between 25 and 200 bar and
a space velocity between 0.2 and 5 kg feed per litre catalyst per
hour. Preferably, gas/feed ratios are applied between 250 and
2000 Nl/kg.
Feedstocks which can suitably be subjected to a
hydroconversion process using a catalyst according to the present
invention comprise gas oils, deasphalted oils, coker gas oils and
other thermally cracked gas oils and syncrudes, optionally
originating from tar sands, shale oils, residue upgrading processes
or biomass. Combinations of various feedstocks can be applied.
It may be desirable to subject part or all of the feedstock to
one or more (hydro)treatment steps prior to its use in the
hydroconversion process. It is often convenient to sub~ect the
feedstock to a (partial) hydrotreatment. The catalyst to be applied
in such a hydrotreatment is suitably an amorphous hydrocracking
catalyst which contains at least one metal of Group VI and/or at
least one metal of Group VIII on an amorphous carrier. In an
attractive embodiment of such a hydrotreatment use is made of two
reaction zones arranged in series whereby the complete effluent
from the first reaction zone can be passed to the second reaction
21~259
zone. The first reaction zone comprises a first amorphous
hydrocracking catalyst as described hereinbefore and the second
reaction zone comprises a second, zeolitic hydrocracking catalyst
which contains at least one metal of Group VI and/or at least one
metal of Group VIII. Preferablyl the zeolitic catalyst comprises a
catalyst composition in accordance with the invention. In this way
a very attractive hydrotreatment of a feedstock is established.
Therefore, the present invention also relates to a process for the
hydrotreatment of a hydrocarbonaceous feedstock comprising
contacting said feedstock in the presence of hydrogen with a first
amorphous hydrocracking catalyst which contains at least one metal
of Group VI and/or at least one metal of Group VIII on an amorphous
carrier in a first reaction zone passing at least part of the
effluent fro~ the first reaction zone, preferably the complete
effluent, to a second reaction zone and contacting in the second
reaction zone said effluent from the first reaction zone in the
presence of hydrogen at elevated temperature and pressure with a
second, zeolitic catalyst which comprises any composition of matter
in accordance with the present invention as defined hereinabove and
at least one hydrogenation component of a Group VI metal and/or at
least one hydrogenation component of a Group VIII metal.
It is evident that the first reaction zone may comprise one or
more beds of the alumina-containing catalyst and also the second
reaction zone may contain one or more beds of the zeolitic
catalyst. It is also evident that the first and second reactor zone
or zones may be located in one or more reactors. Preferably, the
reaction zones are arranged in a stacked-bed configuration. The
hydrotreatment and the process according to the present invention
can also suitably be carried out in reactors in series or in a
stacked-bed configuration.
The reactor effluent so obtained can suitably be subjected to
a further hydrocracking process, preferably to a process in
accordance with the present i~vention.
The present invention will now be illustrated by means of the
3S following Example.
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Example
a) Preparation of a catalyst according to the present invention
77.7 g of a modified Y zeolite (ex-PQZ) having a unit cell
size of 2.431 nm, a SiO2/A1203 molar ratio of 9.8, a water
adsorption capacity (at 25 C and a p/pO value of 0.2) of 11.2% by
weight, a nitrogen pore volume of 0.42 ml/g wherein 30% of the
total pore volume is made up of pores having a diameter of at least
8 nm, a loss of ignition of 11% by weight and a 3670 cm 1/3630 cm 1
infrared absorbance ratio of less than 0.01 was mixed with 24 g of
hydrated aluminium oxide (ex-Criterion). Subsequently, 36.12 g of a
NiW solution (ex-Starck: 6% by weight Ni, 23~ by weight ~), 3.41 g
of a nickel nitrate solution (14% by weight Ni) and 43.02 g of
water were added to the powdery mixture. After mulling the mixture
obtained it was extruded in a small Bonnot extruder provided with a
die plate producing 1.5 mm extrudates. The extrudates obtained were
dried for 2 hours at 120 C and finally calcined for 2 hours at 500
C. The extrudates obtained had a mercury pore volume of 0.61 ml/g.
They contained 2.6% by weight of nickel and 8.2% by weight of
tungsten. The ready catalyst contained 80% by weight of modified Y
zeolite and 20% by weight of binder (based on total amount of
zeolite and binder on a dry basis).
b) Hydrocracking experiment.
The catalyst obtained was subjected to a hydrocracking
performance test invol.ving a hydrotreated heavy vacuum gas oil
having the following properties:
C (%wt) : 86.2
H (%wt) : 13.8
d (70/4) : 0.826
viscosity (100 C) : 4.87 cS (ASTM-D-445)
viscosity (60 C) : 12.43 cS (ASTM-D-445)
RCT (%wt) : 0.05 (ASTM-D-542)
I.B.P. (C) : 205 C
10/20 : 332/370
30/40 : 392/410
50/60 : 428/44~
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70/80 : 467/492
: 525
F.B.P. : 598
The catalyst was firstly subjected to a presulphiding
treatment by slowly heating in a 10 ~v H2S/~I2-atmosphere to a
temperature of 370 C. The catalyst was tested in a 1:1 dilution
with 0.2 mm SiC particles under the following operating conditions:
WHSV of 1.1 kg/l/h, H2S partial pressure of 1.4 bar, total pressure
of 130 bar and a gas/feed ratio of 1,000 Nl/kg. The experiment was
carried out in once-through operation.
When operating the hydrocracking in a kerosene mode of operation,
the catalyst performance is expressed at 70% by weight conversion
of 300 C boiling point material in the feed after allowing the
catalyst to stabilize.
The following results were obtained with the catalyst:
Temperature required (70% conv. of 300 C ): 328 C
Distribution of 300 C product (in % by weight):
Cl -C4 : 6
C5 - 130 C : 43
130 C - 300 C : 51
The chemical hydrogen consumption amounted to 1.2% by weight.
Comparative Exam~le
A modified Y zeolite known from EP-B-247679 and having a unit cell
size of 24.33 A, a SiO2/A1203 molar ratio of 9.85, a water
adsorption capacity (at 25 C and a p/pO value of 0.2) of 11.3% by
weight, a nitrogen pore volume of 0.40 ml/g wherein 18% of the
total pore volume is made up of pores having a diameter of at least
8 nm, a loss of ignition of 14.1% by weight and a 3670 cm /3630
cm 1 infrared absorbance ratio of 0.043 was treated with hydrated
aluminium oxide (ex-Criterion) and a solution of nickel nitrate and
am~onium metatungstate so as to obtain a catalyst containing 2.6%
by weight of nlckel and 8.2% by weight of tungsten. The ready
catalyst contained 77.5~ by weight of modified ~ zeolite and 22.5%
by weight of binder (based on total amount oi zeolite and binder on
a dry basis).
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The comparative catalyst was subjected to a presulphiding
treatment as described in the Example and subjected to the same
feed. ~hen operating the hydrocracking in a kerosene mode (i.e.
expressing catalyst performance at 70% by weight conversion of
300 C boiling point material in the feed) after allowing the
catalyst to stabilize, the following results were obtained:
Temperature required (70~ conv. of 300 C ): 318 C
Distribution of 300 C product (in ~ by weîght):
Cl - C4 7
C5 - 130 C : 46
130 C - 300 C : 47
The chemical hydrogen consumption amounted to 1.2% by weight.
It will be clear from the above that the catalyst in
accordance with the present invention is more attractive in terms
of gas make and middle distillate yield than the catalyst known
from EP-B-247679.
