U.S. patent application number 11/628691 was filed with the patent office on 2008-02-21 for process to make a base oil.
Invention is credited to Gerard Benard, Gilbert Robert Bernard Germaine.
Application Number | 20080045614 11/628691 |
Document ID | / |
Family ID | 34931155 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080045614 |
Kind Code |
A1 |
Benard; Gerard ; et
al. |
February 21, 2008 |
Process to Make a Base Oil
Abstract
Process to prepare a base oil having a kinematic viscosity at
100.degree. C. of greater than 6 cSt from a Fischer-Tropsch derived
wax having a T10wt % recovery boiling point of above 500.degree. C.
by performing the following steps, (a) contacting a feed comprising
the Fischer-Tropsch wax and between 5 and 40 wt % of a hydrocarbon
diluent having a T90wt % recovery point of below 400.degree. C.
with a hydro-isomerisation catalyst under hydro-isomerisation, and
(b) dewaxing the isomerised product of step (a) and isolating the
base oil from the dewaxed oil obtained in step (b).
Inventors: |
Benard; Gerard; (Petit
Couronne, FR) ; Germaine; Gilbert Robert Bernard;
(Petit Couronne, FR) |
Correspondence
Address: |
SHELL OIL COMPANY
P O BOX 2463
HOUSTON
TX
772522463
US
|
Family ID: |
34931155 |
Appl. No.: |
11/628691 |
Filed: |
June 7, 2005 |
PCT Filed: |
June 7, 2005 |
PCT NO: |
PCT/EP05/52620 |
371 Date: |
December 6, 2006 |
Current U.S.
Class: |
518/724 |
Current CPC
Class: |
C10G 2400/10 20130101;
C10N 2020/02 20130101; C10M 2205/173 20130101; C10M 171/02
20130101; C10M 109/02 20130101; C10N 2030/02 20130101; C10N 2030/74
20200501 |
Class at
Publication: |
518/724 |
International
Class: |
C10G 65/04 20060101
C10G065/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 8, 2004 |
EP |
04291433.3 |
Claims
1. A process to prepare a base oil having a kinematic viscosity at
100.degree. C. of greater than 6 cSt from a Fischer-Tropsch derived
wax having a T10wt % recovery boiling point of above 500.degree. C.
comprising: (a1) performing a Fischer-Tropsch synthesis to prepare
a Fischer-Tropsch synthesis product; (a2) isolating, by means of
distillation, from said Fischer-Tropsch synthesis product a
Fischer-Tropsch wax, an intermediate wax product boiling for more
than 80 wt % between 300 and 500.degree. C., and a hydrocarbon
diluent having a T90 wt % recovery point of below 400.degree. C.;
and (a3) combining the Fischer-Tropsch wax and the diluent to form
a feed to step (a); (a) contacting the feed comprising the
Fischer-Tropsch wax and between 5 and 40 wt % of a hydrocarbon
diluent having a T90 wt % recovery point of below 400.degree. C.
with a hydro-isomerisation catalyst under hydro-isomerisation
conditions, (b) dewaxing isomerised product of step (a) and
isolating a base oil from the dewaxed oil.
2. The process according to claim 1, wherein the content of the
Fischer-Tropsch wax in the feed to step (a) is greater than 70 wt
%.
3. The process according to claim 1, wherein the diluent is
Fischer-Tropsch derived product.
4. The process according to claim 1, wherein the T10wt % recovery
point of the diluent is between 250 and 370.degree. C.
5. The process according to claim 1, wherein the isomerisation
catalyst used in step (b) comprises nickel, platinum or
palladium.
6. The process according to claim 5, wherein in step (a) a catalyst
is used comprising a silica-alumina carrier and in step (b) a
dewaxing catalyst is used comprising platinum or palladium and
ZSM-48 and wherein steps (a) and (b) are performed in series
flow.
7. The process according to claim 1, wherein the base oil obtained
by the process has a kinematic viscosity at 100.degree. C. of
greater than 8 cSt, a viscosity index of greater than 140 and a
Noack volatility of below 7 wt %.
8. The process according to claim 1, wherein the feed to step (a)
is prepared by performing a Fischer-Tropsch synthesis to prepare a
Fischer-Tropsch synthesis product, isolating, by means of
distillation, from said Fischer-Tropsch synthesis product a
Fischer-Tropsch wax, an intermediate wax product boiling for more
than 80 wt % between 300 and 500.degree. C. and a diluent,
combining the Fischer-Tropsch wax and the diluent to form a feed to
step (a) and keeping separate from the feed to step (a) the
intermediate wax product.
Description
FIELD OF THE INVENTION
[0001] The invention is related to a process to prepare a base oil
having a kinematic viscosity at 100.degree. C. of greater than 7
cSt from a Fischer-Tropsch derived wax by performing first a
hydro-isomerisation followed by a dewaxing step.
BACKGROUND ART
[0002] Such a process is described in EP-A-776959. This publication
discloses that a base oil having a kinematic viscosity at
100.degree. C. of about 5 cSt can be obtained by subjecting a
Fischer-Tropsch derived wax having a congealing point of about
70.degree. C. and a T10 wt % recovery point of about 430.degree. C.
to a hydro-isomerisation step followed by a solvent or catalytic
dewaxing step. The yield of base oil was reported to be about 40 wt
% when performing the process by means of solvent dewaxing.
[0003] A disadvantage of the process as disclosed in EP-A-776959 is
that when base oils having a higher viscosity are desired
significantly lower yields are found.
[0004] The object of the present invention is thus to improve the
yield of base oils having a kinematic viscosity of greater than 7,
especially greater than 8 cSt at 100.degree. C.
SUMMARY OF THE INVENTION
[0005] This object is achieved with the following process. Process
to prepare a base oil having a kinematic viscosity at 100.degree.
C. of greater than 6 cSt from a Fischer-Tropsch derived wax having
a T10wt % recovery boiling point of above 500.degree. C. by
performing the following steps, [0006] (a) contacting a feed
comprising the Fischer-Tropsch wax and between 5 and 40 wt % of a
hydrocarbon diluent having a T90 wt % recovery point of below
400.degree. C. with a hydro-isomerisation catalyst under
hydro-isomerisation conditions, [0007] (b) dewaxing the isomerised
product of step (a) and isolating the base oil from the dewaxed
oil. Applicants found that not only the yield to the high viscosity
base oil can be improved also the viscosity of the end base oil is
higher when processing a feed also containing a diluent.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The Fischer-Tropsch wax used as the feed for the present
process, is obtained via the well-known Fischer-Tropsch hydrocarbon
synthesis process. In general, such Fischer-Tropsch hydrocarbon
synthesis involves the preparation of hydrocarbons from a mixture
of carbon monoxide and hydrogen at elevated temperature and
pressure in the presence of a suitable catalyst. The
Fischer-Tropsch catalyst normally is selective for preparing
paraffinic molecules, mostly straight-chain paraffins, and the
product from a Fischer-Tropsch synthesis reaction therefore usually
is a mixture of a large variety of paraffinic molecules. Those
hydrocarbons that are gaseous or liquid at room temperature are
recovered separately, for instance as fuel gas (C.sub.5--), solvent
feedstocks and detergent feedstocks (up to C.sub.17). The more
heavy paraffins (C.sub.18+) are recovered as one or more wax
fractions, commonly referred to as Fischer-Tropsch wax(es) or
synthetic wax(es). For the purpose of the present invention only
those Fischer-Tropsch waxes are useful as the feed, which meet the
aforementioned requirements with respect to its T10wt % recovery
boiling point.
[0009] The Fischer-Tropsch wax may comprise iso-paraffins. The
presence of iso-paraffins will however be relatively low. A measure
of the amount of iso-paraffins is the oil content of the wax. The
wax content as used in the description is measured according to the
following procedure. 1 weight part of the to be measured oil
fraction is diluted with 4 parts of a (50/50 vol/vol) mixture of
methyl ethyl ketone and toluene, which is subsequently cooled to
-27.degree. C. in a refrigerator. The mixture is subsequently
filtered at -27.degree. C. The wax is removed from the filter and
weighed. If reference is made to oil content a wt % value is meant
which is 100% minus the wax content in wt %. The wax content is
preferably above 50 wt %, more preferably above 60 wt % and even
more preferably between 60 and 100 wt % as measured according to
the above method.
[0010] Within the limits defined hereinbefore, preferred
Fischer-Tropsch wax feeds are those having a congealing point in
the range of above 80.degree. C. and more preferably between 90 and
150.degree. C. Those Fischer-Tropsch waxes melting above 90.degree.
C. suitably have a kinematic viscosity at a temperature T, which is
10 to 20.degree. C. higher than their melting point, in the range
of from 8 to 15 mm.sup.2/s, preferably from 9 to 14 mm.sup.2/s.
[0011] The hydrocarbon diluent used in step (a) may in principle be
any hydrocarbon mixture having a T90 recovery point of below
400.degree. C. Preferably the diluent is a paraffin fraction as
obtained in the above referred to Fischer-Tropsch synthesis. More
preferably it is a fraction boiling for more than 80 wt % between
250 and 400.degree. C. The paraffin diluent may be a heavy
Fischer-Tropsch derived gas oil or a substantially waxy product
having a wax content of above 80 wt %, preferably above 90 wt %.
Mixtures of such products may also be used.
[0012] In a preferred embodiment the feed to step (a) is prepared
by performing a Fischer-Tropsch synthesis to prepare a
Fischer-Tropsch synthesis product. Isolating, by means of
distillation, from said Fischer-Tropsch synthesis product the
Fischer-Tropsch wax as defined above, an intermediate wax product
boiling for more than 80 wt % between 300 and 500.degree. C. and a
lower boiling fraction which is used as diluent as defined above.
The heavy wax fraction and diluent fraction are combined to form
the feed to step (a). The intermediate wax product is a paraffin
wax product having a congealing point of between 45 and 80 or even
as high as 90.degree. C. and more preferably between 50 and
85.degree. C. This wax product is preferably kept separate from the
feed to step (a) and is suitably marketed as paraffin wax. The
intermediate wax product may be further separated in two or more
fractions resulting in wax products having a narrow carbon
distribution. The Fischer-Tropsch wax may be subjected to a
hydrogenation step prior to the above separation. Hydrogenation, or
optionally a mild hydroisomerisation, may suitably be performed on
the intermediate wax product after it has been isolated to obtain a
marketable wax product. The non-hydrogenated blend can be used
directly in step (a).
[0013] The hydroconversion catalyst used in step (a) may in
principle be any catalyst known in the art to be suitable for
isomerising paraffinic molecules. In general, suitable
hydroconversion catalysts are those comprising a hydrogenation
component supported on a refractory oxide carrier, such as
amorphous silica-alumina, alumina, fluorided alumina, molecular
sieves (zeolites) or mixtures of two or more of these. Suitable
catalysts have been found to be those comprising a Group VIII
metal, especially nickel, platinum or palladium and a
silica-alumina carrier as will be described in more detail
below.
[0014] One type of preferred catalysts to be applied in the
hydroconversion step in accordance with the present invention are
hydroconversion catalysts comprising platinum and/or palladium as
the hydrogenation component. A very much preferred hydroconversion
catalyst comprises platinum and palladium supported on an amorphous
silica-alumina (ASA) carrier. The platinum and/or palladium is
suitably present in an amount of from 0.1 to 5.0% by weight, more
suitably from 0.2 to 2.0% by weight, calculated as element and
based on total weight of carrier. If both present, the weight ratio
of platinum to palladium (calculated as element) may vary within
wide limits, but suitably is in the range of from 0.05 to 10, more
suitably 0.1 to 5. Examples of suitable noble metal on ASA
catalysts are, for instance, disclosed in WO-A-94/10264 and
EP-A-0,582,347. Other suitable noble metal-based catalysts, such as
platinum on a fluorided alumina carrier, are disclosed in e.g. U.S.
Pat. No. 5,059,299 and WO-A-92/20759.
[0015] A second type of suitable hydroconversion catalysts are
those comprising at least one Group VIB metal, preferably tungsten
and/or molybdenum, and at least one non-noble Group VIII metal,
preferably nickel and/or cobalt, as the hydrogenation component.
Usually both metals are present as oxides, sulphides or a
combination thereof. The Group VIB metal is suitably present in an
amount of from 1 to 35% by weight, more suitably from 5 to 30% by
weight, calculated as element and based on total weight of
catalyst. The non-noble Group VIII metal is suitably present in an
amount of from 1 to 25% wt, preferably 2 to 15% wt, calculated as
element and based on total weight of carrier. A hydroconversion
catalyst of this type which has been found particularly suitable is
a catalyst comprising nickel and tungsten supported on fluorided
alumina.
[0016] A preferred catalyst which can be used in a non-sulphided
form comprises a non-noble Group VIII metal, e.g., iron, nickel, in
conjunction with a Group IB metal, e.g., copper, supported on an
acidic support. The catalyst has a surface area in the range of
200-500 m.sup.2/gm, preferably 0.35 to 0.80 ml/gm, as determined by
water adsorption, and a bulk density of about 0.5-1.0 g/ml. The
catalyst support is preferably an amorphous silica-alumina where
the alumina is present in amounts of less than about 30 wt %,
preferably 5-30 wt %, more preferably 10-20 wt %. Also, the support
may contain small amounts, e.g., 20-30 wt %, of a binder, e.g.,
alumina, silica, Group IVA metal oxides, and various types of
clays, magnesia, etc., preferably alumina.
[0017] The preparation of amorphous silica-alumina microspheres has
been described in Ryland, Lloyd B., Tamele, M. W., and Wilson, J.
N., Cracking Catalysts, Catalysis: volume VII, Ed. Paul H. Emmett,
Reinhold Publishing Corporation, New York, 1960, pp. 5-9.
[0018] The catalyst is prepared by co-impregnating the metals from
solutions onto the support, drying at 100-150.degree. C., and
calcining in air at 200-550.degree. C. The Group VIII metal is
present in amounts of about 15 wt % or less, preferably 1-12 wt %,
while the Group IB metal is usually present in lesser amounts,
e.g., 1:2 to about 1:20 ratio respecting the Group VIII metal.
[0019] A typical catalyst is shown below: TABLE-US-00001 Ni, wt %
2.5-3.5 Cu, wt % 0.25-0.35 Al.sub.2O.sub.3--SiO.sub.2 wt % 65-75
Al.sub.2O.sub.3 (binder) wt % 25-30 Surface Area 290-325 m.sup.2/gm
Pore Volume (Hg) 0.35-0.45 ml/gm Bulk Density 0.58-0.68 g/ml
[0020] Another class of suitable hydroconversion catalysts are
those based on zeolitic materials, suitably comprising at least one
Group VIII metal component, preferably Pt and/or Pd, as the
hydrogenation component. Suitable zeolitic materials, then, include
Zeolite beta, Zeolite Y, Ultra Stable Y, ZSM-5, ZSM-12, ZSM-22,
ZSM-23, ZSM-35, SSZ-32, ferrierite, zeolite beta, mordenite and
silica-aluminophosphates, such as SAPO-11 and SAPO-31 or said list
and ZSM-48. Examples of suitable hydroisomerisation catalysts are,
for instance, described in WO-A-92/01657.
[0021] The hydroconversion conditions applied in step (a) are those
known to be suitable in hydro-isomerisation operations. Suitable
conditions, then, involve operating temperatures in the range of
from 275 to 450.degree. C., preferably 300 to 425.degree. C., a
hydrogen partial pressure in the range of from 10 to 250 bar,
suitably 25 to 200 bar, a weight hourly space velocity (WHSV) in
the range of from 0.1 to 10 kg/l/h, preferably 0.2 to 5 kg/l/h, and
a gas rate in the range of from 100 to 5,000 Nl/kg, preferably 500
to 3,000 Nl/kg.
[0022] Suitably the conditions in step (a) are so chosen that the
wax conversion is preferably between 40 and 90 wt % and more
preferably between 60 and 90 wt %.
[0023] The effluent of step (a) may be directly used as feed to a
dewaxing step. Especially if catalytic dewaxing is applied in step
(b) it has been found advantageous to perform step (a) and (b) in a
series flow configuration, thus without any intermediate separation
of lower boiling compounds. Alternatively one may separate from the
effluent of step (a) a lighter fraction such to reduce the volume
of feed to step (a). The effective cutpoint of such a separation or
said otherwise of the heavy remaining fraction is suitably in the
range of from 400 to 550.degree. C. The effective cutpoint of the
heavy fraction is the temperature above which at least at least 85%
by weight and preferably at least 90% by weight, of the
hydrocarbons present in this heavy fraction has its boiling point.
This separation or fractionation can be achieved by techniques
known in the art, such as atmospheric and vacuum distillation or
vacuum flashing.
[0024] In step (b) the base oil precursor fraction obtained in step
(a) is subjected to a pour point reducing treatment. With a pour
point reducing treatment is understood every process wherein the
pour point of the base oil is reduced by more than 10.degree. C.,
preferably more than 20.degree. C., more preferably more than
25.degree. C.
[0025] The pour point reducing treatment can be performed by means
of a so-called solvent dewaxing process or by means of a catalytic
dewaxing process. Solvent dewaxing is well known to those skilled
in the art and involves admixture of one or more solvents and/or
wax precipitating agents with the base oil precursor fraction and
cooling the mixture to a temperature in the range of from
-10.degree. C. to -40.degree. C., preferably in the range of from
-20.degree. C. to -35.degree. C., to separate the wax from the oil.
The oil containing the wax is usually filtered through a filter
cloth which can be made of textile fibres, such as cotton; porous
metal cloth; or cloth made of synthetic materials. Examples of
solvents which may be employed in the solvent dewaxing process are
C.sub.3-C.sub.6 ketones (e.g. methyl ethyl ketone, methyl isobutyl
ketone and mixtures thereof), C.sub.6-C.sub.10 aromatic
hydrocarbons (e.g. toluene), mixtures of ketones and aromatics
(e.g. methyl ethyl ketone and toluene), autorefrigerative solvents
such as liquefied, normally gaseous C.sub.2-C.sub.4 hydrocarbons
such as propane, propylene, butane, butylene and mixtures thereof.
Dichloromethane and mixtures of methyl ethyl ketone and toluene or
methyl ethyl ketone and methyl isobutyl ketone are generally
preferred. Examples of these and other suitable solvent dewaxing
processes are described in Lubricant Base Oil and Wax Processing,
Avilino Sequeira, Jr, Marcel Dekker Inc., New York, 1994, Chapter
7.
[0026] The slack wax obtained in the solvent dewaxing treatment of
step (b) is suitably recycled, i.e. all or part of this slack wax
is routed back to the hydroconversion step (a), most conveniently
by blending it with the fresh Fisher-Tropsch wax feed, provided the
feed characterisation is still within the definition according to
the present invention. In this way the final yield of lubricating
base oil can be maximised.
[0027] Preferably step (b) is performed by means of a catalytic
dewaxing process. With such a process it has been found that base
oils having a pour point of even below -40.degree. C. can be
prepared when starting from a base oil precursor fraction as
obtained in step (a) of the present process.
[0028] The catalytic dewaxing process can be performed by any
process wherein in the presence of a catalyst and hydrogen the pour
point of the base oil precursor fraction is reduced as specified
above. Suitable dewaxing catalysts are heterogeneous catalysts
comprising a molecular sieve and optionally in combination with a
metal having a hydrogenation function, such as the Group VIII
metals. Molecular sieves, and more suitably intermediate pore size
zeolites, have shown a good catalytic ability to reduce the pour
point of the base oil precursor fraction under catalytic dewaxing
conditions. Preferably the intermediate pore size zeolites have a
pore diameter of between 0.35 and 0.8 nm. Suitable intermediate
pore size zeolites are mordenite, ZSM-5, ZSM-12, ZSM-22, ZSM-23,
SSZ-32, ZSM-35 and ZSM-48. Another preferred group of molecular
sieves are the silica-aluminaphosphate (SAPO) materials of which
SAPO-11 is most preferred as for example described in U.S. Pat. No.
4,859,311. ZSM-5 may optionally be used in its HZSM-5 form in the
absence of any Group VIII metal. The other molecular sieves are
preferably used in combination with an added Group VIII metal.
Suitable Group VIII metals are nickel, cobalt, platinum and
palladium. Examples of possible combinations are Pt/ZSM-35,
Ni/ZSM-5, Pt/ZSM-23, Pd/ZSM-23, Pt/ZSM-48 and Pt/SAPO-11. Further
details and examples of suitable molecular sieves and dewaxing
conditions are for example described in WO-A-9718278, U.S. Pat. No.
4,343,692, U.S. Pat. No. 5,053,373, U.S. Pat. No. 5,252,527 and
U.S. Pat. No. 4,574,043.
[0029] The dewaxing catalyst suitably also comprises a binder. The
binder can be a synthetic or naturally occurring (inorganic)
substance, for example clay, silica and/or metal oxides. Natural
occurring clays are for example of the montmorillonite and kaolin
families. The binder is preferably a porous binder material, for
example a refractory oxide of which examples are: alumina,
silica-alumina, silica-magnesia, silica-zirconia, silica-thoria,
silica-beryllia, silica-titania as well as ternary compositions for
example silica-alumina-thoria, silica-alumina-zirconia,
silica-alumina-magnesia and silica-magnesia-zirconia. More
preferably a low acidity refractory oxide binder material, which is
essentially free of alumina, is used. Examples of these binder
materials are silica, zirconia, titanium dioxide, germanium dioxide
and mixtures of two or more of these of which examples are listed
above. The most preferred binder is silica.
[0030] A preferred class of dewaxing catalysts comprise
intermediate zeolite crystallites as described above and a low
acidity refractory oxide binder material which is essentially free
of alumina as described above, wherein the surface of the
aluminosilicate zeolite crystallites has been modified by
subjecting the aluminosilicate zeolite crystallites to a surface
dealumination treatment. A preferred dealumination treatment is by
contacting an extrudate of the binder and the zeolite with an
aqueous solution of a fluorosilicate salt as described in for
example U.S. Pat. No. 5,157,191 or WO-A-0029511. Examples of
suitable dewaxing catalysts as described above are silica bound and
dealuminated Pt/ZSM-5, silica bound and dealuminated Pt/ZSM-23,
silica bound and dealuminated Pt/ZSM-12, silica bound and
dealuminated Pt/ZSM-22, as for example described in WO-A-0029511
and EP-B-832171.
[0031] Catalytic dewaxing conditions are known in the art and
typically involve operating temperatures in the range of from 200
to 500.degree. C., suitably from 250 to 400.degree. C., hydrogen
pressures in the range of from 10 to 200 bar, preferably from 40 to
70 bar, weight hourly space velocities (WHSV) in the range of from
0.1 to 10 kg of oil per litre of catalyst per hour (kg/l/hr),
suitably from 0.2 to 5 kg/l/hr, more suitably from 0.5 to 3 kg/l/hr
and hydrogen to oil ratios in the range of from 100 to 2,000 litres
of hydrogen per litre of oil. By varying the temperature between
275, suitably between 315 and 375.degree. C. at between 40-70 bars,
in the catalytic dewaxing step it is possible to prepare base oils
having different pour point specifications varying from suitably
-10 to -60.degree. C.
[0032] Optionally steps (a) and (b) may be performed in one step
using the same catalyst comprising a molecular sieve. Optionally
steps (a) and (b) can be performed using a molecular sieve
comprising catalyst in both steps wherein the pore opening of the
molecular sieve in step (a) is larger than the molecular sieve used
in step (b) suitably making use of the catalysts as exemplified at
steps (a) and (b) above.
[0033] The invention is now further illustrated by the following
examples without restricting the scope of the invention to these
specific embodiments.
[0034] In the experiments use was made of wax feedstocks A and D.
These wax feedstocks were prepared by hydrogenation of a
Fischer-Tropsch synthesis product followed by distillate separation
using wiped film evaporators. Products B and C are the intermediate
wax products as discussed also above. These wax products B and C
having a narrow carbon distribution may find application in for
example hot melt adhesives, printing inks, cable filling, match
sticks, corrugated board, fibre board and PVC lubricants. The
unique white colour of these waxes make them ideal for application
requiring colour additive, e.g. crayons, candles, graphic arts and
other decorative items. The opaque appearance produces true colour
brilliance with minimum colouring agents. TABLE-US-00002 TABLE 1
feedstock A B C D Kinematic 4.663 n.a. n.a. n.a. viscosity at
40.degree. C. (cSt) Kinematic n.a. 2.929 5.520 n.a. viscosity at
100.degree. C.(cSt) Kinematic n.a. n.a. n.a. 12.97 viscosity at
120.degree. C.(cSt) Congealing 30 50 70 100 point (.degree. C.)
Initial boiling 287 316 337 492 point (.degree. C.) T 10 wt % 305
362 432 530 recovery point (.degree. C.) T 50 wt % 337 405 483 591
recovery point (.degree. C.) T 90 wt % 362 437 529 655 recovery
point (.degree. C.) Final boiling 389 460 575 685 point n.a. = not
analysed
Comparative Experiment A
[0035] A Fischer-Tropsch wax feed B having the properties as listed
in Table I was contacted with a fluorided NiW/alumina catalyst
(5.0% wt Ni, 23.1% wt W, 4.6% wt F, all based on total weight of
carrier) at a temperature ranging from 370 to 400.degree. C., a
hydrogen partial pressure of 140 bar, a WHSV of 1 kg/l/h and a gas
rate of 1,500 Nl/kg. The effluent was fractionated and the
390.degree. C.+ fraction (obtained at a yield of 87.8% by weight
based on total effluent) was subsequently solvent dewaxed using
MEK/toluene at -20.degree. C. It was found that the final base oil
yield had a maximum at 388.degree. C. reactor temperature. In table
2 the results are presented.
Comparative Experiment B
[0036] Experiment A was repeated for feed C at various reactor
temperatures ranging from 383 to 399.degree. C. It was seen that
the final base oil yield had a maximum at 389.degree. C. reactor
temperature. In table 2 the results are presented.
Comparative Experiment C
[0037] Experiment A was repeated for feed D at a reactor
temperature of 409 and 420.degree. C. At 409 a maximum base oil
yield was observed. In table 2 the results are presented.
EXAMPLE 1
[0038] Experiment A was repeated except that the feed consisted of
20 wt % of feed A and 80 wt % of feed D. The reactor temperature
ranged from 403 to 420.degree. C. The results are presented in
Table 2. TABLE-US-00003 TABLE 2 Ex. A B C C 1 1 1 Feed Feed B Feed
C Feed D Feed D 20% 20% 20% Feed Feed Feed A/80% A/80% A/80% feed D
feed D feed D Reactor 388 389 409 420 395 405 420 temperature Base
oil 27.3 47.5 27.4 18.2 31.7 40.6 <3.7 yield (wt % on feed) Pour
point -18 -15 -18 -18 -21 -18 n.a. (.degree. C.) Kinematic 3.147
4.712 7.240 7.240 8.986 8.495 n.a. viscosity at 100.degree. C.
(cSt) Viscosity 145 148 148 148 154 157 n.a. Index Noack 23.1 9.0
7.2 7.2 4.4 5.9 n.a. volatility (wt %)
EXAMPLE 2
[0039] The Fischer-Tropsch feed as used in Example 1 was contacted
with a PtPd/ASA (0.3% wt Pt, 1% wt Pd, ASA: silica/alumina molar
ratio is 55/45) catalyst at a different temperatures, whilst the
other conditions were the same as applied in Example 1. The
effluent was fractionated and the 390.degree. C.+ fraction and the
residue was subsequently solvent dewaxed using MEK/toluene at
-20.degree. C.
[0040] The results are presented in FIG. 1. In this FIGURE also
some results of Examples according to Example 1 are presented for
comparison reasons. The oil obtained at the highest yield had a VI
of 150, a pour point of -24.degree. C., a kinematic viscosity at
100.degree. C. (Vk100) of 9.161 mm.sup.2/s and a Noack volatility
of 5.8% by weight.
EXAMPLE 3
[0041] As Example 2 but at a hydrogen partial pressure of 90 bar.
See FIG. 1 for results. The oil obtained at the highest yield had a
VI of 146, a pour point of -27.degree. C., a kinematic viscosity at
100.degree. C. (Vk100) of 8.13 mm.sup.2/s and a Noack volatility of
7.2% by weight.
EXAMPLE 4
[0042] As Example 2 but at a hydrogen partial pressure of 40 bar.
See FIG. 1 for results. The oil obtained at the highest yield had a
VI of 151, a pour point of -24.degree. C., a kinematic viscosity at
100.degree. C. (Vk100) of 8.317 mm.sup.2/s and a Noack volatility
of 6.7% by weight.
* * * * *