U.S. patent application number 14/355995 was filed with the patent office on 2014-12-04 for method for producing fuel oil.
The applicant listed for this patent is Kitakyushu foundation for the Advancement of Industry, Science and Technology. Invention is credited to Sachio Asoaka, Toshiyuki Kimura, Xiaohong Li.
Application Number | 20140357924 14/355995 |
Document ID | / |
Family ID | 48429585 |
Filed Date | 2014-12-04 |
United States Patent
Application |
20140357924 |
Kind Code |
A1 |
Asoaka; Sachio ; et
al. |
December 4, 2014 |
METHOD FOR PRODUCING FUEL OIL
Abstract
Provided is a method that is for producing fuel oil and that is
able to cheaply and highly efficiently produce a fuel oil--or
starting material thereof--having as the primary component
n-paraffin or isoparaffin from a starting material oil containing
triglyceride fatty acids, even while reducing hydrogen pressure.
The method for producing fuel oil has a step for producing fuel oil
having one or both of n-paraffin and isoparaffin as the primary
component by contacting hydrogen gas and a starting material oil
containing triglyceride fatty acids under the condition of a
hydrogen pressure of no greater than 2 MPa to a catalyst resulting
from supporting on a porous metal oxide support one or more metal
elements belonging to group nine or group ten of the periodic
table, and one or more group six element oxides belonging to group
six of the periodic table. The weight ratio of the group six
elements to the metal elements contained in the catalyst is no
greater than 1.0 in terms of the metal.
Inventors: |
Asoaka; Sachio; (Fukui,
JP) ; Li; Xiaohong; (Fukui, JP) ; Kimura;
Toshiyuki; (Fukui, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kitakyushu foundation for the Advancement of Industry, Science and
Technology |
Fukui |
|
JP |
|
|
Family ID: |
48429585 |
Appl. No.: |
14/355995 |
Filed: |
November 13, 2012 |
PCT Filed: |
November 13, 2012 |
PCT NO: |
PCT/JP2012/079412 |
371 Date: |
August 22, 2014 |
Current U.S.
Class: |
585/733 |
Current CPC
Class: |
C10G 2300/1011 20130101;
C10L 2200/0484 20130101; C10G 3/48 20130101; C10L 2230/22 20130101;
Y02P 30/20 20151101; C10G 3/44 20130101; C10G 3/46 20130101; C10G
3/50 20130101; C10L 1/02 20130101; C10L 1/04 20130101 |
Class at
Publication: |
585/733 |
International
Class: |
C10L 1/02 20060101
C10L001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 15, 2011 |
JP |
2011-249712 |
Claims
1. A method for producing fuel oil, comprising: a step for
producing a fuel oil composed mainly of one or both of n-paraffin
and isoparaffin by contacting: a base oil containing fatty acid
triglyceride, and hydrogen gas with a catalyst, obtained by
supporting one or a plurality of metal elements belonging to group
9 or group 10 of the periodic table and one or a plurality of group
VI element oxides belonging to group 6 of the periodic table on a
porous metal oxide support, under conditions of a hydrogen pressure
of 2 MPa or less; wherein, the weight ratio as metal of the group 6
element contained in the catalyst to the metal element does not
exceed 1.0.
2. The method for producing fuel oil according to claim 1, wherein
the hydrogen pressure is 1 MPa or less.
3. The method for producing fuel oil according to claim 1 or claim
2, wherein the metal element is nickel and/or cobalt, and the group
6 element is molybdenum and/or tungsten.
4. The method for producing fuel oil according to claim 3, wherein
the metal element is nickel and the group 6 element is
molybdenum.
5. The method for producing fuel oil according to any of claims 1
to 4, wherein the porous metal oxide support is .gamma.-alumina or
a modification product thereof.
6. The method for producing fuel oil according to any of claims 1
to 5, wherein the base oil, the hydrogen gas and the catalyst are
contacted under conditions of a liquid hourly space velocity of 0.5
hr.sup.-1 to 20 hr.sup.-1 and a reaction temperature of 250.degree.
C. to 400.degree. C.
7. The method for producing fuel oil according to any of claims 1
to 6, wherein the content of saturated fatty acid groups having 8
to 14 carbon atoms in the fatty acid group composition of fatty
acid triglyceride contained in the base oil is 40% by weight or
more.
8. The method for producing fuel oil according to claim 7, wherein
the content of lauric acid groups in the fatty acid group
composition of the fatty acid triglyceride is 40% by weight or
more.
9. The method for producing fuel oil according to any of claims 1
to 8, wherein the base oil is oil derived from a plant or
bacteria.
10. The method for producing fuel oil according to claim 9, wherein
the oil derived from a plant is a mixture of oils derived from two
or more types of plants.
11. The method for producing fuel oil according to claim 9 or claim
10, wherein the oil derived from a plant is coconut oil, palm
kernel oil or a mixture thereof.
12. The method for producing fuel oil according to claim 9 or 10,
wherein the oil derived from a plant is an oil derived from
algae.
13. The method for producing fuel oil according to any of claims 1
to 12, wherein a fuel oil composed mainly of the resulting base oil
satisfies the requirements for aviation fuel defined in ASTM D
7566.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing fuel
oil from fatty acid triglyceride, and more particularly, to a
method for producing fuel oil that is useful as an aviation
fuel.
BACKGROUND ART
[0002] Biomass fuels, which are non-exhaustible resources that do
not cause an increase in the concentration of carbon dioxide in the
atmosphere (i.e., are carbon neutral), are attracting attention as
fuel oil raw materials to take the place of conventional petroleum
from the viewpoints of growing social demand for reducing levels of
greenhouse gases, escalating crude oil prices and the need to
conserve petroleum resources.
[0003] Known examples of biofuels produced from biomass raw
materials include bioalcohol fuels obtained by direct fermentation
of sugars contained in sugar cane or corn or by fermentation of
sugars obtained by hydrolyzing cellulose contained in sustainable
wood, and biodiesel fuels (BDF) that use fatty acid methyl esters
obtained by transesterification of animal and vegetable oils as
fuel oil. Among these, bioalcohol fuels using sugar cane or corn as
raw materials are associated with problems such as having an effect
on the stable supply of foodstuffs, requiring considerable energy
for removal of water, and being difficult to apply to aviation
fuel. Bioalcohol fuels using cellulose as raw materials are
associated with problems such as high production costs and also
being difficult to apply to aviation fuel.
[0004] Since biodiesel fuel is used by adding to or mixing with
conventional petroleum-based fuels (see, for example, Patent
Document 1), in addition to still being inadequate as a completely
alternative technology to petroleum-based raw materials, it is also
associated with problems such as deterioration caused by oxygen and
freezing at low temperatures. In addition, since it is necessary to
process the glycerin produced as a by-product as well as clean the
oil formed, high production costs are currently a barrier to its
proliferation in the transport industry amidst increasingly intense
price competition.
[0005] Moreover, since biodiesel fuel also contains a large number
of carbon atoms in the fatty acid groups that compose the oil while
also consisting of linear molecules, it also has the shortcoming of
preventing the obtaining of a sufficiently high octane rating.
[0006] In consideration of the aforementioned problems,
biohydrocracking fuels (BHF) have been proposed that consist mainly
of hydrocarbon-based compounds and are obtained by a process
consisting of decomposing plant and vegetable oils in the presence
of hydrogen gas and catalyst using a vacuum-distilled gas oil
hydrocracking device and the like. During the cracking process,
reactions occur that include reduction of carboxyl groups,
shortening of hydrocarbon chains and isomerization of linear alkyl
groups to branched alkyl groups, thereby resulting in the obtaining
of a mixture composed of hydrocarbon compounds having a desired
number of carbon atoms and branching (see Patent Documents 2 to
7).
PRIOR ART DOCUMENTS
Patent Documents
[0007] Patent Document 1: Japanese Unexamined Patent Application
Publication (Translation of PCT Application) No. 2010-532419 [0008]
Patent Document 2: Japanese Unexamined Patent Publication No.
2009-40833 [0009] Patent Document 3: Japanese Unexamined Patent
Publication No. 2009-40855 [0010] Patent Document 4: Japanese
Unexamined Patent Publication No. 2009-40856 [0011] Patent Document
5: Japanese Unexamined Patent Application Publication (Translation
of PCT Application) No. 2011-515539 [0012] Patent Document 6:
Japanese Unexamined Patent Publication No. 2011-52074 [0013] Patent
Document 7: Japanese Unexamined Patent Publication No.
2011-52077
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0014] However, since the production of gas oil compositions
described in Patent Documents 2 to 4, 6 and 7 is carried out at a
high hydrogen pressure of 2 MPa to 13 MPa thereby requiring a
pressure vessel, these gas oil compositions have the problem of
excessively high production costs.
[0015] Production of transportation fuel described in Patent
Document 5 also requires a high hydrogen pressure of about 0.7 MPa
to about 14 MPa during hydrogenation treatment.
[0016] With the foregoing in view, an object of the present
invention is to provide a method for producing base oil enabling
the inexpensive and high-yield production of fuel oil, or raw
material thereof, composed mainly of n-paraffin or isoparaffin,
from base oil containing fatty acid triglyceride.
Means for Solving the Problems
[0017] The present invention solves the aforementioned problems by
providing a method for producing fuel oil according to any of [1]
to [13] below.
[0018] [1] A method for producing fuel oil, comprising: a step for
producing a fuel oil composed mainly of one or both of n-paraffin
and isoparaffin by contacting a base oil containing fatty acid
triglyceride and hydrogen gas with a catalyst, obtained by
supporting one or a plurality of metal elements belonging to group
9 or group 10 of the periodic table and one or a plurality of group
VI element oxides belonging to group 6 of the periodic table on a
porous metal oxide support, under conditions of a hydrogen pressure
of 2 MPa or less; wherein, the weight ratio as metal of the group 6
element contained in the catalyst to the metal element does not
exceed 1.0.
[0019] [2] The method for producing fuel oil described in [1]
above, wherein the hydrogen pressure is 1 MPa or less.
[0020] [3] The method for producing fuel oil described in [1] or
[2] above, wherein the metal element is nickel and/or cobalt.
[0021] [4] The method for producing fuel oil described in [3]
above, wherein the metal element is nickel and the group 6 element
is molybdenum.
[0022] [5] The method for producing fuel oil described in any of
[1] to [4], wherein the porous metal oxide support is
.gamma.-alumina or a modification product thereof.
[0023] [6] The method for producing fuel oil described in any of
[1] to [5] above, wherein the base oil, the hydrogen gas and the
catalyst are contacted under conditions of a liquid hourly space
velocity of 0.5 hr.sup.-1 to 20 hr.sup.-1 and a reaction
temperature of 250.degree. C. to 400.degree. C.
[0024] [7] The method for producing fuel oil described in any of
[1] to [6] above, wherein the content of saturated fatty acid
groups having 8 to 14 carbon atoms in the fatty acid group
composition of fatty acid triglyceride contained in the base oil is
40% by weight or more.
[0025] [8] The method for producing fuel oil described in [7]
above, wherein the content of lauric acid in the fatty acid group
composition of the fatty acid triglyceride is 40% by weight or
more.
[0026] [9] The method for producing fuel oil described in any of
[1] to [8] above, wherein the base oil is oil derived from a plant
or bacteria.
[0027] [10] The method for producing fuel oil described in [9]
above, wherein the oil derived from a plant is a mixture of oils
derived from two or more types of plants.
[0028] [11] The method for producing fuel oil described in [9] or
[10] above, wherein the oil derived from a plant is coconut oil,
palm kernel oil or a mixture thereof.
[0029] [12] The method for producing fuel oil described in [9] or
[10] above, wherein the oil derived from a plant is oil derived
from algae.
[0030] [13] The method for producing fuel oil described in any of
[1] to [12], wherein fuel oil composed mainly of the resulting base
oil satisfies the requirements for aviation fuel defined in ASTM D
7566.
Effects of the Invention
[0031] According to the present invention, a fuel oil composed
mainly of fuel oil raw materials in the form of one or both of
n-paraffin and isoparaffin can be produced inexpensively and at
high yield by hydrocracking fatty acid triglyceride contained in a
base oil at a low hydrogen pressure of 2 MPa or less and preferably
1 MPa or less. Consequently, high-quality fuel oil can be produced
at low cost from carbon-neutral raw materials such as vegetable
oil. Thus, a fuel oil can be provided as a useful alternative to
conventional fossil fuel-derived fuel oils, thereby making it also
possible to present effective solutions for depletion of fossil
fuels as well as environmental issues such as the reduction of
greenhouse gases as exemplified by carbon dioxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a graph indicating the relationship between
reaction time and conversion rate during hydrocracking of palm
oil.
[0033] FIG. 2 is a graph indicating the distribution of the carbon
number of hydrocarbons obtained by hydrocracking of palm oil.
BEST MODE FOR CARRYING OUT THE INVENTION
[0034] Next, an explanation is provided of specific embodiments for
embodying the present invention.
[0035] The catalyst used to carry out the method for producing fuel
oil of the present invention (to be simply referred to as the
"catalyst") is obtained by supporting one or a plurality of types
of metal elements belonging to group 9 or group 10 of the periodic
table and a one or a plurality of types of group 6 element oxides
belonging to group 6 of the periodic table on a porous metal oxide
support.
[0036] A support containing alumina or a compound oxide of silica
and the like mainly composed of alumina can be used for the porous
metal oxide support. Among these, alumina or modified alumina
mainly composed of alumina is preferable from the viewpoint of
increasing the specific surface area of the catalyst. Although
porous .gamma.-alumina (.gamma.-Al.sub.2O.sub.3) is particularly
preferable for the aforementioned alumina, .alpha.-alumina,
.beta.-alumina or amorphous alumina may also be used.
[0037] The alumina serving as the main component of the support may
be produced using any of a method consisting of heat-treating
aluminum hydroxide obtained by neutralizing an aluminum salt with
base, a method consisting of neutralizing or hydrocracking an
aluminum salt and aluminate, or a method consisting of hydrolyzing
an aluminum amalgam or aluminum alcoholate, and may also be
produced using a commercially available alumina intermediate or
boehmite powder and the like as a precursor in addition to the
methods described above.
[0038] In addition to alumina, the porous inorganic oxide support
may also contain silica (SiO.sub.2), silica-alumina
(SiO.sub.2/Al.sub.2O.sub.3), boria (B.sub.2O.sub.3), titania
(TiO.sub.2), magnesia (MgO), activated carbon, diphosphorus
pentoxide (P.sub.2O.sub.5) or a compound oxide thereof.
[0039] Moreover, the aforementioned porous inorganic oxide support
may also contain zeolite as silica-alumina
(SiO.sub.2/Al.sub.2O.sub.3). Zeolite is the generic term for
aluminosilicate having fine pores in the crystals thereof, and
specific examples thereof include natural zeolite compounds such as
amicite (monoclinic system), ammonioleucite, analcime, berbergate,
bikitaite, bauxite, chabazite, sodium chabazite, potassium
chabazite, oblique protyl chabazite, oblique protyl potassium
chabazite, oblique protyl sodium chabazite, oblique protyl calcium
chabazite, cowlesite, calcium dachiardite, sodium dachiardite,
edingtonite, epistilbite, erionite, sodium erionite, potassium
erionite, calcium erionite, ferrierite, magnesium ferrierite,
potassium ferrierite, sodium ferrierite, garronite, gismondite,
gmelinite, sodium gmelinite, calcium gmelinite, potassium
gmelinite, gobbinsite, gonnardite, harmotome, heulandite, calcium
heulandite, strontium-lithium heulandite, sodium heulandite,
potassium heulandite, laumontite, leucite, calcium levyne, sodium
levyne, mesolite, sodium zeolite, phillipsite, sodium phillipsite,
potassium phillipsite, calcium phillipsite, pollucite, scolecite,
stellerite, stilbite, calcium stilbite, sodium stilbite,
thomsonite, wairakite or yugawaralite, and synthetic zeolite
compounds such as type A zeolite, type Y zeolite, type X zeolite,
type beta zeolite or ZSM-5 zeolite.
[0040] In addition, in the case of using zeolite for the porous
metal oxide support, there are no particular limitations on the
structure thereof, and may be type Y zeolite, type X zeolite, type
beta zeolite or ZSM-5 zeolite and the like, or may be a mixture
containing two or more arbitrary types thereof.
[0041] "Group 9 or group 10 of the periodic table" respectively
refers to group 9 or group 10 of the long periodic table (IUPAC
periodic table), and specific examples of metal elements belonging
to these groups include cobalt (Co), nickel (Ni), rhodium (Rh),
palladium (Pd), iridium (Ir) and platinum (Pt). Among these metal
elements, cobalt and nickel are preferable in terms of catalytic
activity and price, and nickel is particularly preferable. The
catalyst contains one type of two or more arbitrary types of these
metals, and is supported on the surface of the porous metal oxide
support in the form of a metal.
[0042] "Group 6 of the periodic table" refers to group 6 of the
long periodic table (IUPAC periodic table), and specific examples
of elements belonging to this group (referred to as "group 6
elements" in the present invention) include chromium (Cr),
molybdenum (Mo) and tungsten (W). Among these, molybdenum and
tungsten are preferable, and molybdenum is particularly preferable.
The catalyst contains one type or two or more arbitrary types of
these metals, and is supported on the surface of the porous metal
oxide support in the form of an oxide.
[0043] Metal elements belonging to group 9 or group 10 of the
periodic table have catalytic activity in a hydrocracking reaction
of fatty acid triglyceride contained in the base oil, and oxides of
elements belonging to group 6 of the periodic table are thought to
impart basicity to the catalyst and contribute to improvement of
dispersibility of the aforementioned metals. The weight ratio as
metal of a group 6 element to a metal element belonging to group 9
or group 10 of the periodic table does not exceed 1.0. Namely, in
the case of defining the weight of a metal element belonging to
group 9 or group 10 of the periodic table as w.sub.1 and defining
the weight of a group 6 element as metal as w.sub.2, then
(w.sub.2/w.sub.1).ltoreq.1. If w.sub.2/w.sub.1 exceeds 1,
conversion efficiency and hydrocarbon yield of the base oil
decrease due to a decrease in hydrocracking activity. The
preferable range of w.sub.2/w.sub.1 is 0.05 to 1.0, more preferably
0.1 to 0.7, and even more preferably 0.15 to 0.5.
[0044] The catalyst is produced by carrying out hydrogen reduction
treatment after impregnating an aqueous solution containing a salt
of a group 6 element and an aqueous solution containing a salt of a
metal belonging to group 9 or group 10 of the periodic table into a
porous metal oxide support and firing. There are no particular
limitations on the salts used to produce the catalyst provided they
are soluble in water, and salts of inorganic acids such as
nitrates, halides, sulfates or phosphates, or salts of organic
acids such as carboxylates, can be used. Furthermore, a salt of a
polyacid or a salt of a heteropolyacid are used preferably for the
salt of the group 6 element since they can be acquired
comparatively inexpensively. Although a salt of a group 6 element
and a salt of a metal belonging to group 9 or group 10 of the
periodic table may be supported simultaneously by impregnating an
aqueous solution containing both followed by firing and carrying
out hydrogen reduction treatment, they may also be supported by
impregnating one followed by firing and hydrogen reduction and then
impregnating the other followed by firing and hydrogen reduction
treatment. Alternatively, hydrogen reduction treatment may be
carried out after having carried out impregnation and firing in
that order.
[0045] An arbitrary animal oil or vegetable oil containing fatty
acid triglyceride as the main component thereof can be used without
any particular limitations for the base oil used in the production
of fuel oil. Since the fatty acid group composition (carbon number
and degree of unsaturation) of fatty acid triglyceride contained in
the base oil has an effect on the carbon number and content of each
hydrocarbon compound that composes the resulting fuel oil, a
suitable base oil can be suitably selected and used corresponding
to the required performance, carbon number and so forth of the
desired base oil. Specific examples of oils and fats used as base
oil include vegetable oils such as corn oil, soybean oil, sesame
oil, rapeseed oil (canola oil), rice oil, rice bran oil, camellia
oil, safflower oil (safflower seed oil), palm kernel oil, coconut
oil, cottonseed oil, sunflower oil, perilla oil, olive oil, peanut
oil, almond oil, avocado oil, hazelnut oil, walnut oil, grape seed
oil, mustard oil, lettuce oil, cocoa butter, palm oil or oils
produced by algae such as marine algae or microalgae, animal oils
and fats such as fish oil, whale oil, shark oil, liver oil, lard
(pork tallow), beef drippings (beef tallow), chicken oil, rabbit
tallow, mutton tallow, horse fat, milk fat or butter, and fats and
oils produced by bacteria.
[0046] Many of the aforementioned animal and vegetable oils are
derived from food raw materials in the form of agricultural crops
and livestock, and there are some that present problems from the
viewpoint of ensuring a stable supply due to problems involving
competition over food resources and difficulty in large-scale
cultivation. Therefore, oils such as jatropha oil and other
non-edible oils can be used as base oils that do not compete with
food, and in particular, oil may be used that is derived from
microalgae, which have superior propagative power, demonstrate a
high production output of oil per unit volume, and can be easily
cultivated on a large scale. The use of base oil derived from
microalgae offers the advantages of being able to significantly
reduce base oil procurement costs and transport costs, while also
making it possible to hold down the price of fuel oil to a low
level.
[0047] Examples of microalgae able to be used as supply sources of
base oil include Botoryococcus braunii, Chlorella species and
Aurantiochytrium species. An example of a base oil derived from
microalgae composed mainly of fatty acid triglyceride suitable for
the production of aviation fuel having a carbon number of 8 to 14
and saturated fatty acid group content of 40% by weight or more in
the fatty acid group composition thereof is oil derived from
microalgae deposited under accession number FERM P-22090.
[0048] Among fuel oils, aviation fuel is required to consist mainly
of n-paraffin and isoparaffin having a carbon number of about 8 to
14 and demonstrate superior low-temperature properties (with
respect to cloud point, solidification temperature and the like).
Base oil for efficiently producing fuel oil able to satisfy these
requirements is preferably a base oil composed mainly of fatty acid
triglyceride in which the content of saturated fatty acid groups
having 8 to 14 carbon atoms in the fatty acid group composition of
fatty acid triglyceride contained in the base oil is 40% by weight
or more, and particularly preferably that in which the content of
lauric acid groups is 40% by weight or more. Specific examples of
the aforementioned animal and vegetable oils that are preferable as
raw materials of aviation fuel include coconut oil harvested from
coconut seeds, palm kernel oil harvested from African oil palm
trees, and oil harvested from algae, and particularly
microalgae.
[0049] In the case of a high free fatty acid content of the base
oil, although pretreatment for removing free fatty acids may be
carried out as necessary, since free fatty acids can also be
converted to hydrocarbons by hydrogenation although more severe
conditions are required than in the case of fatty acid
triglycerides, base oils containing free fatty acids may be used as
is.
[0050] Fuel oil can be efficiently obtained at a low hydrogen
pressure of 2 MPa or lower and preferably 1 MPa or lower, and at a
comparatively low reaction temperature of 250.degree. C. to
400.degree. C. by using the aforementioned catalyst and base oil in
combination. Since hydrogen pressure can be lowered, it is not
necessary to use a reaction vessel having high pressure resistance,
and since there is also relatively little susceptibility to the
effects of hydrogen embrittlement in reaction vessels made of
metal, there are fewer restrictions on production equipment and
fuel oil can be produced at low cost.
[0051] The liquid hourly space velocity (LHSV) during the reaction
is, for example 0.5 hr.sup.-1 to 20 hr.sup.-1, and the hydrogen/oil
ratio is, for example, 50 NL/L to 4000 NL/L. These values are
suitably adjusted corresponding to such factors as the composition
of the base oil and the required performance of the fuel oil (e.g.,
carbon number, low-temperature flow properties).
[0052] Fuel oil obtained in this manner has for a main component
thereof n-paraffin having a carbon number roughly equal to the
carbon number of the fatty acid groups contained in the base oil.
In cases in which it is necessary to improve the content of
isoparaffin, isomerization treatment may be carried out using any
known catalyst such as a platinum catalyst or solid acid catalyst.
Furthermore, in the case of using .gamma.-alumina and the like for
the porous metal oxide support, there are cases in which the
formation of isoparaffin is observed due to isomerization
proceeding simultaneously as a result of this acting as a solid
acid catalyst. In such cases, the amount of time required for the
isomerization step required for improving isoparaffin content can
be shortened, and depending on the case, the isomerization step can
be omitted. Consequently, fuel oil production costs can be reduced
particularly in cases in which it is necessary to improve
isoparaffin content.
[0053] Fuel oil can also be obtained by suitably adding additives
such as antioxidants or anti-freezing agents as necessary. In the
case of using palm oil or oil derived from microalgae as base oil
in particular, fuel oil is obtained that satisfies the requirements
for aviation fuel defined in ASTM D 7566.
[0054] The main regulations relating to aviation turbine fuel oil
containing synthetic hydrocarbons as defined in ASTM D 7566
(American Society for Testing and Materials) are as indicated
below. [0055] Hydrocarbon oils: 99.5% or more [0056]
Cycloparaffins: 15% or less [0057] Paraffin-based hydrocarbon oils:
70% to 85% [0058] Olefin-based hydrocarbons: 5% or less [0059]
Aromatic compounds: 0.5% or less [0060] Acidity: 0.10 mgKOH/g or
less [0061] Sulfur compounds: 3 ppm or less
EXAMPLES
[0062] The following provides an explanation of examples carried
out to confirm the action and effects of the present invention.
Example 1
Catalyst Preparation
[0063] <1> Preparation of .gamma.-Al.sub.2O.sub.3
[0064] 3900 cc of an aqueous aluminum nitrate solution having a
concentration of 2.67 mol/L and 3900 cc of an aqueous ammonia
solution having a concentration of 14% by weight were prepared.
Next, a pH swing procedure was repeated six times consisting of
placing 20 L of pure water in a 30 L porcelain enameled container
followed by heating to 70.degree. C. while stirring, continuing to
stir while injecting 650 cc of the aforementioned aqueous aluminum
nitrate solution and stirring for 5 minutes (pH value: 2.0), and
injecting 650 cc of the aforementioned aqueous ammonia solution and
stirring for 5 minutes (pH 7.4). A washing procedure, consisting of
recovering a cake by filtering the resulting aqueous aluminum
hydroxide slurry followed by re-dispersing the cake in 20 L of pure
water and filtering again, was repeated three times to obtain a
washed cake of the aluminum hydroxide. Next, after adjusting the
water content of the washed cake by drying, the cake was molded
into the shape of rods having a diameter of 1.6 mm with an
extrusion molding machine, and after drying under conditions of
120.degree. C. for 3 hours, the molded rods were crushed to a
length of about 1 cm followed by firing in a muffle furnace under
conditions of 500.degree. C. for 3 hours to obtain a
.gamma.-alumina support.
[0065] The specific surface area of the resulting .gamma.-alumina
support was 275 m.sup.2/g, the pore volume was 0.65 cc/g, the mean
pore diameter was 8.9 nm (89 .ANG.), and the ratio of pores having
a pore diameter within .+-.3 nm (30 .ANG.) of the mean pore
diameter to the total pore volume was 91%. The pore size
distribution of the .gamma.-alumina support obtained according to
this method was extremely small, and the support was able to be
confirmed to have a porous structure consisting of pores having a
uniform pore diameter.
[0066] <2> Preparation of Hydrocracking Catalyst (1)
[0067] After impregnating 100 g of the aforementioned porous
inorganic oxide support into 97 cc of an aqueous nickel nitrate
solution adjusted to a concentration of 0.5 mol/L using the
aforementioned porous inorganic oxide support and allowing to stand
undisturbed for 12 hours in a sealed container, moisture was
removed at normal temperature with an evaporator followed by firing
in air with an electric furnace under conditions of 200.degree. C.
for 3 hours to obtain various fired products in which nickel (Ni)
was supported on a porous inorganic oxide support. Next, each of
the resulting fired products was filled into a flow-type hydrogen
reduction device followed by carrying out hydrogen reduction in the
presence of a hydrogen flow under conditions of 370.degree. C. for
15 hours to obtain a hydrocracking catalyst (1).
[0068] <3> Preparation of Hydrocracking Catalyst (2)
[0069] After impregnating an aqueous solution, obtained by
dissolving 7.19 g of ammonium molybdate
[(NH.sub.4).sub.6Mo.sub.7O.sub.24.4H.sub.2O] in 65.92 cc of pure
water, into 100 g of the hydrocracking catalyst (1) obtained in the
manner described above and allowing to stand undisturbed for 12
hours in a sealed container, moisture was removed at normal
temperature with an evaporator followed by firing with an electric
furnace in air under conditions of 200.degree. C. for 3 hours,
filling the fired product into a flow-type hydrogen reduction
device, and carrying out hydrogen reduction in the presence of
flowing hydrogen under conditions of 370.degree. C. for 15 hours to
prepare a hydrocracking catalyst (2) in which molybdic acid
(MO.sub.3) was added at a ratio of 5% based on the aforementioned
hydrocracking catalyst.
[0070] The supported amount of nickel as nickel metal (Ni supported
amount) in the resulting hydrocracking, catalyst (2) was 22% by
weight, and the supported amount of molybdic acid (MoO.sub.3)
(MoO.sub.3 supported amount) was 5% by weight.
[0071] <4> Preparation of Hydrocracking Catalyst (3)
[0072] After impregnating an aqueous solution, obtained by
dissolving 4.72 g of ammonium tungstenate
[5(NH.sub.4).sub.2.12WO.sub.3.5H.sub.2O] in 65.92 cc of aqueous
aminoethanol solution, into 100 g of the hydrocracking catalyst (1)
obtained in the manner described above and allowing to stand
undisturbed for 12 hours in a sealed container, moisture was
removed at normal temperature with an evaporator followed by firing
with an electric furnace in air under conditions of 200.degree. C.
for 3 hours, filling the fired product into a flow-type hydrogen
reduction device, and carrying out hydrogen reduction in the
presence of flowing hydrogen under conditions of 370.degree. C. for
15 hours to prepare a hydrocracking catalyst (3) in which tungstic
acid (WO.sub.3) was added at a ratio of 5% based on the
hydrocracking catalyst (1). The supported amount of nickel as
nickel metal (Ni supported amount) in the resulting hydrocracking
catalyst (3) was 15% by weight, and the supported amount of
tungstic acid (WO.sub.3) (WO.sub.3 supported amount) was 5% by
weight.
Example 2
Production of Fuel Oil Using Coconut Oil as Base Oil
[0073] Hybrid coconut oil used as base oil contained constituent
fatty acid groups mainly consisting of 45% by weight to 52% by
weight of lauric acid (12:0), 15% by weight to 22% by weight of
myristic acid (14:0), 6% by weight to 10% by weight of caprylic
acid (8:0), 4% by weight to 12% by weight of capric acid (10:0), 1%
by weight to 5% by weight of stearic acid (18:0), 2% by weight to
10% by weight of oleic acid (18:1) and 1% by weight to 3% by weight
of linoleic acid (18:2). (Furthermore, numbers shown in parentheses
indicate the carbon number and number of double bonds. In addition,
percentages indicate percent by weight, and to apply similarly
hereinafter). Hydrocracking was carried out under the following
conditions using this hybrid coconut oil as base oil. [0074]
Reaction temperature: 350.degree. C. [0075] LHSV: 1.0 h [0076]
Reaction pressure: 0.8 MPa [0077] H.sub.2/fatty acid triglyceride
flow rate ratio: 1250 NL/L [0078] Amount of catalyst: 2.0 mL [0079]
Catalyst particle diameter: 355 .mu.m to 600 in
[0080] Furthermore, the catalyst used was the hydrocracking
catalyst (2) prepared in section <3> of the aforementioned
Example 1, and pretreatment in the form of hydrogen reduction
treatment was carried out for 7 hours at 370.degree. C. and
GHSV=5000 h.sup.-1. The relationship between reaction time and
conversion rate is shown in FIG. 1, while the distribution of the
carbon numbers of the resulting hydrocarbons is shown in FIG.
2.
[0081] As is shown in FIG. 1, the conversion rate in this reaction
demonstrated a value of nearly 100%, while as shown in FIG. 2, the
products consisted mainly of C.sub.11 hydrocarbons, and nearly all
of those C.sub.11 hydrocarbons consisted of normal paraffin. In
addition, although the results of calculating the yields of the
resulting liquid hydrocarbons, the yield of the aviation fuel
fraction indicating the ratio of aviation fuel fractions (C.sub.7
to C.sub.16) among liquid hydrocarbons, and the average carbon
number of the aviation fuel fractions are shown in the following
Table 1, both liquid hydrocarbon yield and aviation fuel fraction
yield were extremely high at 94.6% and 89.7%, respectively, thereby
confirming that results were able to be obtained that are
comparable to the case of using fatty acid triglyceride obtained
from microalgae-derived oil as base oil. In addition, cloud point,
acidity and sulfur compound content all satisfied the regulations
of ASTM D 7566.
TABLE-US-00001 TABLE 1 Conversion Rate, Paraffin Content, Olefin
Content, Liquid Hydrocarbon Yield, Aviation Fuel Fraction Yield and
Average Carbon Number Conversion rate (%) 100.0 Paraffin content
(wt %) 100.0 Olefin content (wt %) 0.0 Liquid hydrocarbon yield (%)
94.6 Aviation fuel fraction yield (%) 89.7 Aviation fuel fraction
average carbon number 10.3
Example 3
Production of Fuel Oil Using Microalgae Oil-Derived Fatty Acid
Triglyceride as Base Oil
[0082] Microalgae deposited under accession number FERM P-22090
were cultured, the fatty acid group composition of fatty acid
triglyceride sampled therefrom (as analyzed by GC/MS analysis of
fatty acid methyl esters formed by transesterification using
methanol) was as shown in the following Table 2, and the ratio of
lauric acid (C.sub.11H.sub.23COOH) in the fatty acid group
composition was determined to be 40% by weight or more.
TABLE-US-00002 TABLE 2 Fatty Acid Group Composition of Microalgae
Oil-Derived Fatty Acid Triglyceride Fatty acid groups in microalgae
oil-derived fatty acid triglyceride (wt %) Caprylic acid groups
(8:0) 4.6 Capric acid groups (10:0) 5.0 Lauric acid groups (12:0)
48.1 Myristic acid groups (14:0) 19.7 Palmitic acid groups (16:0)
10.3 Stearic acid groups (18:0) 4.1 Oleic acid groups (18:1) 8.1
Linoleic acid groups (18:2) 0.0 Linolenic acid groups (18:3)
0.0
[0083] Hydrocracking was carried out in the same manner as the
aforementioned Example 2 using microalgae oil-derived fatty acid
triglyceride as base oil. The conversion rate, paraffin and
isoparaffin contents, liquid hydrocarbon yield, aviation fuel
fraction yield and aviation fuel fraction average carbon number are
shown in Table 3. In addition, the results of measuring the carbon
number distribution in the fuel oil are shown in Table 4.
TABLE-US-00003 TABLE 3 Reaction Results Using Microalgae
Oil-Derived Fatty Acid Triglyceride as Base Oil Conversion rate (%)
100.0 Paraffin content (wt %) 100.0 Olefin content (wt %) 0.0
Liquid hydrocarbon yield (%) 94.8 Aviation fuel fraction yield (%)
91.0 Aviation fuel yield average carbon number 10.5
TABLE-US-00004 TABLE 4 Product Carbon Number Ratios Carbon number
Raw material (wt %) Product (wt %) C.sub.4 0 0 C.sub.5 0 0.6
C.sub.6 0 0.5 C.sub.7 0 3.5 C.sub.8 4.6 3.2 C.sub.9 0 4.1 C.sub.10
5.0 3.5 C.sub.11 0 32.3 C.sub.12 48.1 18.5 C.sub.12 0 9.9 C.sub.14
19.7 5.0 C.sub.15 0 6.5 C.sub.16 10.3 3.5 C.sub.17 0 9.0 C.sub.18
12.2 0
[0084] As shown in Table 3, in the case of using hydrocracking
catalyst (2), extremely high hydrocarbon yield and aviation fuel
fraction yield were able to be obtained. In addition, the liquid
hydrocarbon yield, aviation fuel fraction (C.sub.7 to C.sub.16)
yield among liquid hydrocarbons and the average carbon number were
calculated based on a value of 100% for the yield assuming
deoxygenation of all raw materials. As shown in Table 4, products
were distributed centering on C.sub.11, odd-numbered and
even-numbered hydrocarbons were formed, and the ratio of
odd-numbered hydrocarbons to even-numbered hydrocarbons was
confirmed to be roughly 2:1. Although nearly all of the products
consisted of normal paraffin, since normal paraffin is a liquid at
normal temperatures, there were not thought to be any problems with
respect to fluidity. In addition, precipitation of wax crystals was
not observed even when cooled to -40.degree. C. Values satisfying
the regulations of ASTM D 7566 were measured for acidity and sulfur
content.
[0085] Furthermore, although fatty acid triglyceride harvested by
culturing microalgae deposited under accession number FERM P-22090
were used as base oil in Example 3, a fatty acid triglyceride
mixture having a fatty acid group composition as shown in Table 2,
for example, may also be prepared and used as a base oil by
blending oils (fatty acid triglycerides) derived from two or more
known types of plants (which may be algae, including microalgae, or
bacteria) in an arbitrary ratio.
* * * * *