Technical Field
[0001] The present invention relates to C heavy oil compositions and methods for producing
the same, more specifically to a C heavy oil composition used as fuel for combustion
devices such as boilers, diesel devices and gas turbines and ships.
Background Art
[0002] C heavy oil has been widely used as fuels for external combustion devices such as
boilers, diesel engine devices of large ships and power generators, or gas turbine
devices.
[0003] C heavy oils having been used for various purposes, in particular for ships are often
loaded in other foreign countries and frequently make engine troubles caused by the
poor combustibility, which have been serious problems. Consequently, a C heavy oil
having excellent ignitability and combustibility and making no combustion trouble
has been increasingly demanded (see Non-Patent Literature 1).
[0004] In order to improve the combustibility of such a C heavy oil, Patent Literature 1
(Japanese Patent Application Laid-Open Publication No.
8-277396) discloses a method wherein heavy oil is formed into an oil-in-water type heavy oil
emulsion with water and a specific nonionic surface active agent and adjusted in emulsion
particle diameter and viscosity to specific ranges and combusted after pre-heating.
[0005] Alternatively, Patent Literature 2 (Japanese Patent Application Laid-Open Publication
No.
2003-96474) discloses a method for improving the combustibility of C heavy oil by inclusion
of 50 percent or more of a light cycle oil (LCO) and specifying the cetane index.
[0006] However, in recent years, fuel for ships has been significantly degraded in quality
as described above and thus has produced sludge and been degraded in ignitability
and combustibility. As the result, the large diesel engines on the ships frequently
have combustion troubles which cause high smoke emission, increased exhaust temperature,
contamination of the exhaust system and abnormal abrasion in cylinders or rings. The
above literatures do not represent any practical solution.
Citation List
Patent Literature
[0007]
Patent Literature 1: Japanese Patent Application Laid-Open Publication No. 8-277396
Patent Literature 2: Japanese Patent Application Laid-Open Publication 2003-96474
Non-Patent Literature
Summary of Invention
Technical Problem
[0009] The present invention has been accomplished in view of the above-described situations
and has an object to provide a C heavy oil composition which unlikely forms sludge,
is excellent in ignitability and combustibility and enables the stable operation of
combustion devices such as external combustion devices, diesel devices, gas turbine
device and the like.
Solution to Problem
[0010] As the result of extensive studies to achieve the above object, the present invention
has been accomplished on the basis of the finding that the above problems can be dissolved
using a specific base oil.
[0011] That is, the present invention is described as follows:
[1] a method for producing a C heavy oil composition with a bicyclic aromatic hydrocarbon
content of 10 percent by volume or more and 45 percent by volume or less, comprising
blending a cracked reformed base oil with a total aromatic content of 80 percent by
volume or more and a 15°C density of 0.90 to 1.20 g/cm3 in an amount of 1 percent by volume or more and 45 percent by volume or less on the
basis of the total mass of the composition;
[2] the method for producing a C heavy oil composition according to [1] above, wherein
the cracked reformed base oil has a 50°C kinematic viscosity of 0.3 to 10 mm2/s, a sulfur content of 8000 mass ppm or less, and a nitrogen content of 100 mass
ppm or less;
[3] the method for producing a C heavy oil composition according to [1] or [2] above,
wherein the cracked reformed base oil has a 10 vol.% distillation temperature (T10)
of 130 to 270°C, a 50 vol.% distillation temperature (T50) of 190 to 290°C, and a
90 vol.% distillation temperature (T90) of 230 to 390°C;
[4] the method for producing a C heavy oil composition according to any of [1] to
[3] above wherein the cracked reformed base oil is produced by bringing a feedstock
having a 10 vol.% distillation temperature of 140°C or higher and a 90 vol.% distillation
temperature of 380°C or lower into contact with a catalyst for a cracking and reforming
reaction containing a medium pore zeolite and/or a large pore zeolite to be cracked
and reformed through a cracking and reforming reaction at a reaction temperature of
400 to 650°C and a reaction pressure of 1.5 MPaG or lower for a contact time of 1
to 300 seconds; and
[5] a C heavy oil composition produced by the method for producing a C heavy oil composition
according to any of [1] to [4] above wherein it has a 15°C density of 0.85 to 1.05
g/cm3, a 50°C kinematic viscosity of 400 mm2/s or lower, a sulfur content of 3.5 percent by mass or less, a nitrogen content of
1 percent by mass or less and a flash point of 70°C or higher.
Advantageous Effect of Invention
[0012] The C heavy oil composition of the present invention unlikely forms sludge and is
excellent in ignitability and combustibility. Therefore, the C heavy oil composition
of the present invention is very useful as fuel for external combustion devices such
as boilers, diesel engine devices of large ships and power generators, and gas turbine
devices.
Description of Embodiments
[0013] Preferred embodiments of the present invention will be described in detail below.
[0014] The method for producing a C heavy oil composition of the present invention is characterized
by blending a cracked reformed base oil with a total aromatic content of 80 percent
by volume or more and a 15°C density of 0.90 to 1.20 g/cm
3, in an amount of 1 percent by volume or more and 45 percent by volume or less on
the basis of the total mass of the C heavy oil composition.
[0015] The lower limit amount of the cracked reformed base oil is necessarily 1 percent
by volume or more, preferably 5 percent by volume or more, more preferably 10 percent
by volume or more, more preferably 15 percent by volume or more on the basis of the
total mass of the C heavy oil composition. The upper limit amount of the cracked reformed
base oil is necessarily 45 percent by volume or less, preferably 40 percent by volume
or less, more preferably 35 percent by volume or less. A blend ratio of the cracked
reformed base oil of less than 1 percent by volume is not preferred because sludge
is likely to be formed due to the degraded compatibility. A blend ratio of more than
45 percent by volume is not preferred because the combustibility would be degraded.
[0016] The total aromatic content of the cracked reformed base oil to be blended in the
C heavy oil composition of the present invention is necessarily 80 percent by volume
or more, preferably 90 percent by volume or more with the objective of retaining the
compatibility as a cutter stock. The total aromatic content referred herein denotes
the content of the total aromatics measured in accordance with the Japan Petroleum
Institute standard JPI-5S-49-97 "Petroleum Products-Determination of Hydrocarbon Types-High
Performance Liquid Chromatography".
[0017] The 15°C density of the cracked reformed base oil to be blended in the C heavy oil
composition of the present invention is necessarily 0.90 g/cm
3 or higher and 1.20 g/cm
3 or lower. The 15°C density referred herein denotes the value obtained in accordance
with JIS K2249 "Crude petroleum and petroleum products-Determination of density and
petroleum measurement tables based on a reference temperature (15°C)".
[0018] No particular limitation is imposed on the properties of the cracked reformed base
oil to be blended in the C heavy oil composition of the present invention other than
the total aromatic content and 15°C density. However, the cracked reformed base oil
has preferably the following properties.
[0019] The 50°C kinematic viscosity of the cracked reformed base oil to be blended in the
C heavy oil composition of the present invention is 0.3 mm
2/s or higher and 10 mm
2/s or lower. The upper limit of the 50°C kinematic viscosity is more preferably 8
mm
2/s or lower, more preferably 6 mm
2/s or lower as a high-quality cutter stock for C heavy oil.
[0020] The content of sulfur (sulfur content) of the cracked reformed base oil to be blended
in the C heavy oil composition of the present invention is preferably 8000 mass ppm
or less and with the objective of reducing the amount of sulfur compounds in the combustion
exhaust gas, more preferably 5000 mass ppm or less, more preferably 4000 mass ppm
or less.
[0021] The content of nitrogen (nitrogen content) of the cracked reformed base oil to be
blended in the C heavy oil composition of the present invention is preferably 100
mass ppm or less and with the objective of reducing the amount of nitrogen compounds
in the combustion exhaust gas, 80 mass ppm or less, more preferably 70 mass ppm or
less.
[0022] The distillation characteristics of the cracked reformed base oil to be blended in
the C heavy oil composition of the present invention are an initial boiling point
(IBP) of preferably 105°C or higher and 250°C or lower, more preferably 120°C or higher
and 240°C or lower, a 10 vol.% distillation temperature (T10) of preferably 130°C
or higher and 270°C or lower, more preferably 150°C or higher and 250°C or lower,
a 50 vol.% distillation temperature (T50) of preferably 190°C or higher and 290°C
or lower, more preferably 210°C or higher and 270°C or lower, a 90 vol.% distillation
temperature (T90) of preferably 230°C or higher and 390°C or lower, more preferably
250°C or higher and 370°C or lower and an end point(EP) of preferably 300°C or higher
and 440°C or lower, more preferably 320°C or higher and 420°C or lower.
[0023] The 50°C kinematic viscosity referred herein denotes the value obtained in accordance
with JIS K2283 "Crude petroleum and petroleum products-Determination of kinematic
viscosity and calculation of viscosity index from kinematic viscosity". The sulfur
content referred herein denotes the sulfur content measured in accordance with "Radiation
Exciting Method" of "Crude Oil and Petroleum Products-Sulfur Content Test Method"
specified in JIS K2541-1992. The nitrogen content referred herein denotes the nitrogen
content measured in accordance with JIS K2609 "Crude petroleum and petroleum products-Determination
of nitrogen content". The distillation characteristics are measured in accordance
with JIS K2254 "Atmospheric Distillation Test Method" of "Petroleum Products-Distillation
Test Method".
[0024] The cracked reformed base oil used in the present invention is characterized in that
it is produced by bringing a feedstock having a 10 vol.% distillation temperature
of 140°C or higher and a 90 vol.% distillation temperature of 380°C or lower into
contact with a catalyst for a cracking and reforming reaction containing a medium
pore zeolite and/or a large pore zeolite to be cracked and reformed through a cracking
and reforming reaction at a reaction temperature of 400 to 650°C and a reaction pressure
of 1.5 MPaG or lower for a contact time of 1 to 300 seconds.
[0025] Specifically, the cracked reformed base oil used in the present invention is produced
by fractional distillation of the cracking and reforming reaction product produced
through the cracking and reforming reaction.
[0026] The cracking and reforming reaction is a reaction wherein a feedstock is brought
into contact with a catalyst for a cracking and reforming reaction to use saturated
hydrocarbons contained in the feedstock as a hydrogen source and subject the saturated
hydrocarbons to a hydrogen transfer reaction to partially hydrogenate the polycyclic
aromatic hydrocarbons so as to be ring-opened and converted to monocyclic aromatic
hydrocarbons or a reaction wherein saturated hydrocarbons contained in the feedstock
or produced through a cracking process is cyclized and dehydrated to monocyclic aromatic
hydrocarbons, and can produce a fuel base oil containing mainly aromatic hydrocarbons.
[0027] The feedstock for the cracking and reforming reaction is an oil preferably having
a 10 vol.% distillation temperature of 140°C or higher and a 90 vol.% distillation
temperature of 380°C or lower, more preferably a 10 vol.% distillation temperature
of 150°C or higher and a 90 vol.% distillation temperature of 360°C or lower.
[0028] The 10 vol.% distillation temperature and 90 vol.% distillation temperature referred
herein denote the values measured in accordance with JIS K2254 "Petroleum products-Determination
of distillation characteristics".
[0029] Examples of the feedstock having a 10 vol.% distillation temperature of 140°C or
higher and a 90 vol.% distillation temperature of 380°C or lower include light cycle
oils (LCO) produced in a fluid catalytic cracker, hydrorefined oils of LCO, liquefied
coal oils, hydrocracked oils from heavy oils, straight-run kerosene, straight-run
gas oil, coker kerosenes, coker gas oils, and hydrocracked oils from oil sands.
[0030] Examples of the reaction format employed when the feedstock is brought into contact
with a catalyst for the cracking and reforming reaction include fixed beds, moving
beds, and fluidized beds. Since in the present invention, a heavy fraction is used
as the feedstock, a fluidized bed is preferred as it can remove the coke portion deposited
on the catalyst in a continuous manner and enables the reaction to proceed in a stable
manner. Particularly preferred is a continuous regeneration type fluidized bed, in
which the catalyst is circulated between the reactor and a regenerator so that a reaction-regeneration
cycle can be continuously repeated. When the feedstock is brought into contact with
a catalyst for a cracking and reforming reaction, it is preferably in a gaseous state.
The feedstock may be diluted with gas if necessary.
[0031] The catalyst for the cracking and reforming reaction contains a crystalline aluminosilicate.
[0032] The crystalline aluminosilicate is preferably a medium pore zeolite and/or a large
pore zeolite as they can enhance the yield of monocyclic aromatic hydrocarbons.
[0033] Medium pore zeolites are those having a 10-membered ring basic structure and may
be any of those having AEL, EUO, FER, HEU, MEL, MFI, NES, TON, and WEI type crystal
structures. Among these zeolites, MFI-type zeolites are preferred as they can further
enhance the yield of monocyclic aromatic hydrocarbons.
[0034] Large pore zeolites are those having a 12-membered ring basic structure. Examples
of the macroporous zeolite include those having AFI, ATO, BEA, CON, FAU, GME, LTL,
MOR, MTW and OFF type crystal structures. Among these zeolites, preferred are those
having BEA, FAU and MOR type structures because they can be used for industrial purposes
and more preferred are those having a BEA type structure because they can increase
the yield of monocyclic aromatic hydrocarbons.
[0035] Other than the above medium pore and large pore zeolites, the crystalline aluminosilicate
may contain small pore zeolites having a 10-membered ring or smaller basic structure
and extra-large pore zeolites having a 14-membered ring or larger basic structure.
[0036] Examples of the small pore zeolites include those having ANA, CHA, ERI, GIS, KFI,
LTA, NAT, PAU and YUG type crystal structures.
[0037] Examples of the extra-large pore zeolites include those having CLO and VPI type crystal
structures.
[0038] In the case where the cracking and reforming reaction is carried out in a fixed bed,
the content of the crystalline aluminosilicate in the catalyst for the cracking and
reforming reaction is preferably from 60 to 100 percent by mass, more preferably from
70 to 100 percent by mass, particularly preferably from 90 to 100 percent by mass
on the basis of 100 percent by mass of the whole catalyst. If the crystalline aluminosilicate
content is 60 percent by mass or more, the yield of monocyclic aromatic hydrocarbons
can be sufficientlyincreased. In the case where the cracking and reforming reaction
is carried out in a fluidized bed, the content of the crystalline aluminosilicate
in the catalyst for cracking and reforming reaction is preferably from 20 to 60 percent
by mass, more preferably from 30 to 60 percent by mass, particularly preferably from
35 to 60 percent by mass on the basis of 100 percent by mass of the whole catalyst.
If the content of the crystalline aluminosilicate is 20 percent by mass or more, the
yield of monocyclic aromatic hydrocarbons can be sufficiently increased. If the content
of the crystalline aluminosilicate is more than 60 percent by mass, the content of
a binder that can be included in the catalyst decreases, and the resulting catalyst
would not be suitable for a fluidized bed.
[0039] The catalyst for the cracking and reforming reaction preferably contains phosphorus
and/or boron. The catalyst for the cracking and reforming reaction if containing phosphorus
and/or boron can prevent the yield of monocyclic aromatic hydrocarbons from decreasing
over time and also inhibit the formation of coke on the catalyst surface.
[0040] Examples of methods for incorporating phosphorus in the catalyst for the cracking
and reforming reaction include ion-exchange methods and impregnation methods. More
specific examples include methods wherein phosphorus is loaded on a crystalline aluminosilicate,
crystalline aluminogallosilicate or crystalline aluminozincosilicate, methods wherein
a phosphorus compound is included during synthesis of the zeolite so that a portion
of the internal framework of the crystalline aluminosilicate is substituted with phosphorus,
and methods wherein a crystallization promoter containing phosphorus is used during
synthesis of the zeolite. No particular limitation is imposed on the phosphate ion-containing
aqueous solution used in the above-mentioned methods. However, preferably used is
a solution prepared by dissolving phosphoric acid, diammonium hydrogen phosphate,
ammonium dihydrogen phosphate or another water-soluble phosphoric acid salt at an
arbitrary concentration in water.
[0041] Examples of methods for incorporating boron in the catalyst for the cracking and
reforming reaction include ion-exchange methods and impregnation methods. More specific
examples include methods wherein boron is loaded on a crystalline aluminosilicate,
crystalline aluminogallosilicate or crystalline aluminozincosilicate, methods wherein
a boron compound is included during synthesis of the zeolite so that a portion of
the internal framework of the crystalline aluminosilicate is substituted with boron,
and methods wherein a crystallization promoter containing boron is used during synthesis
of the zeolite.
[0042] The content of phosphorus and/or boron in the catalyst for the cracking and reforming
reaction is preferably from 0.1 to 10 percent by mass on the basis of the total mass
of the catalyst, wherein the lower limit is more preferably 0.5 percent by mass or
more and the upper limit is more preferably 9 percent by mass or less, particularly
preferably 8 percent by mass. A phosphorus content of 0.1 percent by mass or more
on the basis of the total mass of the catalyst can prevent the yield of monocyclic
aromatic hydrocarbons from decreasing over time, and a phosphorus content of 10 percent
by mass or less can increase the yield of monocyclic aromatic hydrocarbons.
[0043] If necessary, the catalyst for the cracking and reforming reaction may contain gallium
and/or zinc. Inclusion of gallium and/or zinc results in the increased production
rate of monocyclic aromatic hydrocarbons.
[0044] Examples of the form of gallium in the catalyst for the cracking and reforming reaction
include catalysts wherein gallium is incorporated within the lattice framework of
the crystalline aluminosilicate (crystalline aluminogallosilicate), catalysts wherein
gallium is supported on the crystalline aluminosilicate (gallium-supporting crystalline
aluminosilicate) and catalysts including gallium in the both forms.
[0045] Examples of the form of zinc in the catalyst for the cracking and reforming reaction
include catalysts wherein zinc is incorporated within the lattice framework of the
crystalline aluminosilicate (crystalline aluminogallosilicate), catalysts wherein
zinc is supported on the crystalline aluminosilicate (zinc-supporting crystalline
aluminosilicate) and catalysts including zinc in the both forms.
[0046] A crystalline aluminogallosilicate or a crystalline aluminozincosilicate has a structure
in which SiO
4, AlO
4 and GaO
4/ZnO
4 structures exist in the framework. A crystalline aluminogallosilicate or crystalline
aluminozincosilicate may be produced for example by gel-crystallization through hydrothermal
synthesis, or by insertion of gallium or zinc into the lattice framework of a crystalline
aluminosilicate. Alternatively, a crystalline aluminogallosilicate or crystalline
aluminozincosilicate may be produced by insertion of aluminum into the lattice framework
of a crystalline gallosilicate or crystalline zincosilicate.
[0047] A gallium-supporting crystalline aluminosilicate may be produced by loading gallium
on a crystalline aluminosilicate with a conventional method such as an ion-exchange
method or impregnation method. No particular limitation is imposed on the gallium
source used in these methods, and examples of the source include gallium salts, such
as gallium nitrate and gallium chloride, and gallium oxide.
[0048] A zinc-supporting crystalline aluminosilicate may be produced by loading zinc on
a crystalline aluminosilicate with a conventional method such as an ion-exchange method
or impregnation method. No particular limitation is imposed on the zinc source used
in these methods, and examples of the source include zinc salts such as zinc nitrate
and zinc chloride, and zinc oxide.
[0049] In the case where the catalyst for the cracking and reforming reaction contains gallium
and/or zinc, the content of gallium and/or zinc therein is preferably from 0.01 to
5.0 percent by mass, more preferably from 0.05 to 2.0 percent by mass on the basis
of 100 percent by mass of the total mass of the catalyst. Contents of gallium and
zinc of 0.01 percent by mass or more result in the increased production rate of monocyclic
aromatic hydrocarbons, and contents of 5.0 percent by mass or less can further increase
the yield of monocyclic aromatic hydrocarbons.
[0050] The catalyst for the cracking and reforming reaction is formed into powder, granules
or pellets depending on the reaction mode. For example, the catalyst is used in the
form of powder for a fluidized bed and in the form of granules or pellets for a fixed
bed. The average particle diameter of the catalyst used in a fluidized bed is preferably
from 30 to 180 µm, more preferably from 50 to 100 µm. The bulk density of the catalyst
used in a fluidized bed is preferably from 0.4 to 1.8 g/cc, more preferably 0.5 to
1.0 g/cc. The average particle diameter denotes the particle diameter at which the
particle diameter distribution obtained by classification with a sieve is 50 percent
by mass. The bulk density is the value measured in accordance with the method prescribed
in JIS R9301-2-3. In order to produce a granular or pellet catalyst, if necessary,
an inert oxide as a binder may be added to the catalyst, followed by molding with
any of various molding apparatuses.
[0051] In the case where the catalyst for the cracking and reforming reaction contains an
inorganic oxide as a binder, a phosphorus-containing binder may be used.
[0052] No particular limitation is imposed on the reaction temperature at which the feedstock
is brought into contact with and then reacted with the catalyst for the cracking and
reforming reaction. However, the reaction temperature is preferably from 400 to 650°C.
The lower limit reaction temperature needs to be 400°C or higher so as to allow the
easy reaction of the feedstock and is more preferably 450°C or higher. The upper limit
reaction temperature needs to be 650°C or lower so as to increase sufficiently the
yield of monocyclic aromatic hydrocarbons, more preferably 600°C or lower.
[0053] The reaction pressure at which the feedstock is brought into contact with and then
reacted with the catalyst for the cracking and reforming reaction is preferably 1.5
MPaG or lower, more preferably 1.0 MPaG or lower. The reaction pressure if 1.5 MPaG
or lower can restrain the generation of by-product light gas and lower the pressure
resistance in a reactor.
[0054] No particular limitation is imposed on the contact time of the feedstock and the
catalyst for the cracking and reforming reaction if the reaction proceeds as desired.
However, for example, the contact time is preferably from 1 to 300 seconds measured
when the gas passes across the catalyst for the cracking and reforming reaction. The
lower limit contact time is more preferably 5 seconds or longer, and the upper limit
contact time is more preferably 150 seconds or shorter. The contact time if 1 second
or longer ensures the reaction between the feedstock and the catalyst. The contact
time if 300 seconds or shorter can restrain deposition of carbon on the catalyst due
to coking and furthermore suppress the amount of light gas generated by coking.
[0055] The cracked and reformed reaction product generated through the above-described cracking
and reforming reaction is separated into fractions each having given properties thereby
producing the cracked reformed base oil used of the present invention.
[0056] In order to separate the cracked and reformed reaction product into given fractions,
a conventional distillation unit and gas-liquid separation unit may be used. One example
of the distillation unit is a device such as a stripper comprising a multi-stage distillation
unit so as to separate a plurality of fractions by distillation. One example of the
gas-liquid separation unit is a device containing a gas-liquid separation tank, an
inlet pipe for introducing the reaction product into the gas-liquid separation tank,
a gas component discharge pipe arranged in the upper section of the gas-liquid separation
bath and a liquid component discharge pipe arranged in the lower section of the gas-liquid
separation bath.
[0057] The cracked and reformed base oil used in the present invention is preferably a fraction
containing hydrocarbons of 9 or more carbon atoms.
[0058] No particular limitation is imposed on C heavy oil base oils other than the cracked
reformed base oil to be blended in the method for producing the C heavy oil composition
of the present invention. However, examples of such base oils include atmospheric
gas oils, atmospheric residue, residual desulfurized gas oils, vacuum gas oils, vacuum
residue, extract oils, light cycle oil and catalytically cracked residual oils. In
the present invention, the cracked reformed base oil may be used in combination with
one or more types of these C heavy oil base oils. The atmospheric gas oils and atmospheric
residue are gas oils and residual oils produced by distilling crude oil at atmospheric
pressure in an atmospheric distillation unit. The residual desulfurized gas oils are
gas oils produced when atmospheric residue or vacuum residue are desulfurized in a
direct residual oil desulfurization unit. The vacuum gas oils and vacuum residue are
gas oils and residual oils produced by distilling atmospheric residue under reduced
pressure in a vacuum distillation unit. The extract oils are aromatic components among
which are not suitable for lubricating oil, produced by extracting and separating
fractions from a vacuum distillation unit for lubricating oil feedstocks. The light
cycle oil and catalytically cracked residual oils are gas oils and residual oils produced
by cracking vacuum-distilled gas oils and vacuum-distilled residual oils in a fluid
catalytic cracker.
[0059] In the C heavy oil composition of the present invention, these C heavy oil base oils
are blended in an amount of 55 to 99 percent by volume, preferably 60 to 95 percent
by volume, more preferably 65 to 90 percent by volume, most preferably 65 to 85 percent
by volume on the basis of the total mass of the heavy oil composition.
[0060] The C heavy oil composition of the present invention is necessarily a C heavy oil
composition produced using the above-described cracked reformed base oil as an indispensable
component and meeting JIS Third-Class Heavy Oil Standard.
[0061] The method of the present invention produces a C heavy oil composition with a bicyclic
aromatic hydrocarbon content of 10 percent by volume or more and 45 percent by volume
or less. The lower limit bicyclic aromatic hydrocarbon content is preferably 10 percent
by volume or more with the objective of retaining the compatibility to restrain the
sludge formation. The upper limit is preferably 45 percent by volume or less with
the objective of retaining the combustibility.
[0062] The bicyclic aromatic hydrocarbon content used herein denotes the bicyclic aromatic
hydrocarbon content obtained by measuring the aromatic content separated by "a composition
analysis method of asphalt using column chromatography" defined by the Japan Petroleum
Institute standard JPI-5S-22-83 in accordance with "Petroleum Products-Determination
of Hydrocarbon Types-High Performance Liquid Chromatography" defined by the Japan
Petroleum Institute standard JPI-5S-49-97.
[0063] No particular limitation is imposed on the properties of the C heavy oil composition
of the present invention other than the bicyclic aromatic hydrocarbon content. Preferably,
the composition has the following properties.
[0064] The 15°C density (density at 15°C) of the C heavy oil composition of the present
invention is preferably 0.85 g/cm
3 or higher, more preferably 0.88 g/cm
3 or higher, most preferably 0.90 g/cm
3 or higher. The 15°C density is also preferably 1.05 g/cm
3 or lower, more preferably 1.00 g/cm
3 or lower, most preferably 0.99 g/cm
3 or lower. A 15°C density of lower than 0.85 g/cm
3 is not preferred because the heat value per volume would be small. A 15°C density
of higher than 1.05 g/cm
3 is not also preferred because the combustion failure would likely occur.
[0065] The 70°C density (density at 70°C) of the C heavy oil composition of the present
invention is preferably 0.80 g/cm
3 or higher, more preferably 0.83 g/cm
3 or higher. The 70°C density is also preferably 1.00 g/cm
3 or lower, more preferably 0.95 g/cm
3 or lower. A 70°C density of lower than 0.80 g/cm
3 is not preferred because the heat value per volume would be small. A 70°C density
of higher than 1.00 g/cm
3 is not also preferred because the combustion failure would likely occur.
[0066] The densities referred herein denotes the values obtained in accordance with the
JIS K2249 "Crude petroleum and petroleum products-Determination of density and petroleum
measurement tables based on a reference temperature (15°C)".
[0067] The 50°C kinematic viscosity of the C heavy oil composition of the present invention
is preferably 400 mm
2/s or lower, more preferably 350 mm
2/s or lower, most preferably 300 mm
2/s or lower. If the 50°C kinematic viscosity is higher than 400 mm
2/s, the combustion failure of the composition would likely occur.
[0068] The 100°C kinematic viscosity of the C heavy oil composition is preferably 50 mm
2/s or lower, more preferably 45 mm
2/s or lower. If the 100°C kinematic viscosity is higher than 50 mm
2/s, the combustion failure of the composition would likely occur.
[0069] The kinematic viscosities referred herein denotes the values obtained in accordance
with JIS K2283 "Crude petroleum and petroleum products-Determination of kinematic
viscosity and calculation of viscosity index from kinematic viscosity".
[0070] The sulfur content of the C heavy oil composition of the present invention is preferably
3.5 percent by mass or less, more preferably 3.0 percent by mass or less. If the sulfur
content is more than 3.5 percent by mass, the amount of sulfur oxides exhausted from
an engine possibly increases.
[0071] The sulfur content referred herein denotes the remaining carbon content measured
in accordance with JIS K2541 "Crude oil and petroleum products-Determination of sulfur
content".
[0072] The nitrogen content of the C heavy oil composition of the present invention is preferably
1.0 percent by mass or less, more preferably 0.5 percent by mass or less. If the nitrogen
content is more than 1.0 percent by mass, the amount of nitrogen oxides exhausted
from an engine possibly increases.
[0073] The nitrogen content referred herein denotes the remaining carbon content measured
in accordance with JIS K2609 "Crude petroleum and petroleum products-Determination
of nitrogen content".
[0074] The flash point of the C heavy oil composition of the present invention is preferably
70°C or higher, more preferably 72°C or higher from the viewpoint of safety in handling.
[0075] The flash point referred herein denotes the value measured in accordance with the
Pensky-Martens closed cup method of JIS K2265 "Crude oil and petroleum products-Determination
of flash point".
[0076] The CCAI of the C heavy oil composition of the present invention is preferably 900
or smaller, more preferably 870 or smaller. If the CCAI is greater than 900, the combustion
failure of the composition would likely occur.
[0077] The CCAI (Calculated Carbon Aromaticity Index: defined in accordance with the decision
of The International Council on Combustion Engines) used herein is an index focused
on the relation between an aromatic content and ignitability and calculated by the
following formula wherein the density and viscosity of heavy oil are conveniently
represented by aromaticity:
(D: 15°C density (kg/m
3), V: 50°C kinematic viscosity (mm
2/s))
[0078] The carbon residue content of the C heavy oil composition of the present invention
is preferably 15 percent by mass or less, more preferably 10 percent by mass or less.
If the carbon residue content is more than 15 percent by mass, the combustion failure
of the composition would likely occur.
[0079] The carbon residue content referred herein denotes the carbon residue content measured
in accordance with JIS K2270 "Crude petroleum and petroleum products-Determination
of carbon residue".
[0080] The ash content of the C heavy oil composition of the present invention is preferably
0.10 percent by mass or less, more preferably 0.05 percent by mass or less. If the
ash content is more than 0.10 percent by mass, the combustion failure of the composition
would likely occur.
[0081] The ash content referred herein denotes the value obtained in accordance with JIS
K2272 "Testing Methods for Ash and Sulfated Ash of Crude Oil and Petroleum Products".
[0082] The vanadium content of the C heavy oil composition of the present invention is preferably
100 mass ppm or less, more preferably 80 mass ppm or less. If the vanadium content
is more than 100 mass ppm, the combustion failure of the composition would likely
occur.
[0083] The vanadium content denotes the value obtained in accordance with JPI-5S-11 "Method
of Test for Vanadium in Fuel".
[0084] The water content of the C heavy oil composition of the present invention is preferably
0.5 percent by volume or less, more preferably 0.3 percent by volume or less. If the
water content is more than 0.5 percent by volume, the composition would precipitate
in the form of ice and likely cause metal corrosion or filter clogging.
[0085] The water content referred herein denotes the value measured in accordance with JIS
K2275 "Crude oil and petroleum products-Determination of water content".
[0086] The ignition delay of the C heavy oil composition of the present invention measured
with a fuel ignition analyzer is preferably 15 ms or shorter. The ignition delay measured
with a fuel ignition analyzer is preferably 15 ms or shorter, more preferably 13 ms
or shorter, more preferably 11 ms or shorter because a short time period from the
injection of fuel into a combustion chamber till the ignition of the fuel is beneficial
in order to operate diesel engine devices safely.
[0087] The combustion time of the C heavy oil composition of the present invention measured
with a fuel ignition analyzer is preferably 25 ms or shorter. The combustion time
measured with a fuel ignition analyzer is 25 ms or shorter preferably, more preferably
23 ms or shorter because a short flame in the combustion chamber is beneficial in
order to operate a diesel engine device safely.
[0088] The fuel ignition analyzer used in the present invention is "Fuel Ignition Analyzer:
FIA-100" manufactured by FUEL TECH Japan LTD in which about 0.1 ml of fuel heated
to 120°C is injected at an ignition pressure of 20 MPa into a constant-volume combustion
chamber filled with air with a volume of 1 L, a pressure of 4.5 MPa and a temperature
of 450°C thereby measuring the ignition delay and combustion time.
[0089] The ignition delay referred herein denotes the period of time that the pressure in
the combustion chamber increase from the initial pressure to 0.02 MPa.
[0090] The combustion period referred herein denotes the period of time obtained by deducting
the ignition delay time from the time till reaching the maximum pressure.
[0091] The temperature at which the mass of the C heavy oil composition of the present invention
decreases by 10 percent under a nitrogen atmosphere (100 ml/minute) measured with
a thermogravimetry-differential thermal analysis is preferably 400°C or lower, more
preferably 350°C or lower. If the temperature at which the mass decreases by 10 percent
under a nitrogen atmosphere with a thermogravimetry-differential thermal analysis
is higher than 400°C, the combustion failure of the composition would likely occur.
[0092] The thermogravimetry-differential thermal analysis referred herein is an analysis
method wherein a sample is heated under given temperature conditions to measure the
weight decrease associated with vaporization/thermal cracking and the change in calorific
value associated with vaporization/oxidation/thermal cracking at the same time. Specifically,
about 10 mg of a sample is weighed in a 5 mm inner diameter platinum pan and set on
Thermoflex TAS300 manufactured by Rigaku Corporation. The sample is then heated from
room temperature to 1000°C at a rate of 100°C/minute.
[0093] The temperature at which the mass of the C heavy oil composition of the present invention
decreases by 50 percent under a nitrogen atmosphere (100 ml/minute) measured with
a thermogravimetry-differential thermal analysis is preferably 600°C or lower, more
preferably 550°C or lower. If the temperature at which the mass decreases by 50 percent
under a nitrogen atmosphere with a thermogravimetry-differential thermal analysis
is higher than 600°C, the combustion failure of the composition would likely occur.
[0094] The temperature at which the mass of the C heavy oil composition of the present invention
decreases by 90 percent under a nitrogen atmosphere (100 ml/minute) measured with
a thermogravimetry-differential thermal analysis is preferably 800°C or lower, more
preferably 750°C or lower. If the temperature at which the mass decreases by 90 percent
under a nitrogen atmosphere with a thermogravimetry-differential thermal analysis
is higher than 800°C, the combustion failure of the composition would likely occur.
[0095] If necessary, the C heavy oil composition of the present invention may contain various
additive such as cold flow improvers, cetane number improvers, anti-oxidants, stabilizing
agents, dispersants, metal deactivators, microbial sterilizers, combustion improvers,
anti-static agents, identification agent, and coloring agents.
[0096] The above-mentioned additives may be those synthesized in accordance with ordinary
manners or commercially available additives. Some of the commercial available additives
are often in the form in which the active components contributing to the intended
effect are diluted with a suitable solvent. In the case of using commercially available
additives, the effective components of which are diluted, they are preferably added
such that properties of the C heavy oil composition satisfy the above-described requirements.
The amounts of additives are arbitrarily selected, but the total amount of the additives
is usually preferably 0.5 percent by mass or less, preferably 0.2 percent by mass
or less on the basis of the total mass of the C heavy oil composition.
Examples
[0097] The present invention will be described with reference to the following examples
but are not limited thereto.
[Examples and Comparative Examples]
[0098] Test fuels of Examples 1 to 4 were prepared using cracked reformed base oils set
forth in Table 1, a vacuum residue produced by distilling an atmospheric residue under
reduced pressure in a vacuum distillation unit and a straight-run gas oil produced
by distilling crude oil at atmospheric pressure in an atmospheric distillation unit.
For comparison, a sample containing no cracked reformed base oil and a commercially
available product were also prepared.
[0099] The cracked reformed base oils set forth in Table 1 were prepared in the following
manner.
(Method for producing cracked reformed base oils)
[0100] A light cycle oil LCO (a 10 vol.% distillation temperature of 215°C, a 90 vol.% distillation
temperature of 318°C, a 15°C density of 0.9258 g/cm
3, a saturate content of 23 percent by volume, an olefin content of 2 percent by volume
and a total aromatic content of 75 percent by volume) was brought into contact with
and reacted with a catalyst for a cracking and reforming reaction (MFI type zeolite
supporting 0.2 percent by mass of gallium and 0.7 percent by mass of phosphorus and
containing a binder) under conditions of a reaction temperature of 538°C, a reaction
pressure of 0.3 MPaG, an LCO and catalyst contact time of 60 seconds in a fluidized
bed reactor so as to carry out a cracking and reforming reaction. The cracked and
reformed reaction product was fractioned by distillation thereby producing cracked
and reformed base oils 1 to 3 set forth in Table 1.
[0101] Evaluation results of these samples are set forth in Table 2. The properties of the
C heavy oil compositions were measured in accordance with the above-described test
methods and measurement methods.
[0102] Measurement of dry sludge was carried out in accordance with ISO 10307-1.
[0103] It is found from Table 2 that the C heavy oil compositions of the present invention
are equal to or better than the commercially available product in ignitability and
combustibility and can restrain sludge formation.
[Table 1]
|
|
|
Cracked reformed base oil 1 |
Cracked reformed base oil 2 |
Cracked reformed base oil 3 |
Cracked reformed base oil properties |
Density (@15°C) |
(g/cm3) |
1.19 |
0.95 |
1.01 |
Kinematic viscosity (@50°C) |
(mm2/s) |
0.5 |
9.8 |
5.1 |
Sulfur content |
(mass ppm) |
3120 |
2050 |
2510 |
Nitrogen content |
(mass ppm) |
78 |
62 |
43 |
Distillation characteristics |
|
|
|
IBP |
(°C) |
233.5 |
158.0 |
185.0 |
T10 |
(°C) |
237.5 |
187.0 |
192.5 |
T50 |
(°C) |
252.0 |
238.0 |
237.0 |
T90 |
(°C) |
299.0 |
280.0 |
290.5 |
EP |
(°C) |
363.0 |
362.0 |
362.5 |
Total aromatic content |
(volume %) |
100 |
100 |
100 |
[Table 2]
|
|
Example 1 |
Example 2 |
Example 3 |
Example 4 |
Comparative Example 1 |
Comparative Example 2 |
Vacuum residue |
(volume %) |
87 |
60 |
70 |
78 |
73 |
Commercially available C heavy oil |
Cracked reformed base oil 1 |
(volume %) |
13 |
|
|
5 |
|
Cracked reformed base oil 2 |
(volume %) |
|
40 |
|
|
|
Cracked reformed base oil 3 |
(volume %) |
|
|
30 |
|
|
Straight-run gas oil |
(volume %) |
|
|
|
17 |
27 |
Density (@15°C) |
(g/m3) |
0.970 |
0.943 |
0.959 |
0.944 |
0.927 |
0.962 |
Kinematic viscosity (@50°C) |
(mm2/s) |
194 |
148 |
179 |
178 |
179 |
178 |
Carbon residue content |
(mass %) |
7.6 |
7.8 |
7.9 |
7.6 |
8.1 |
10.4 |
Ash content |
(mass %) |
0.002 |
0.003 |
0.004 |
0.002 |
0.004 |
0.021 |
Vanadium content |
(mass ppm) |
26 |
18 |
21 |
23 |
22 |
50 |
Sulfur content |
(mass %) |
2.70 |
2.71 |
2.88 |
2.62 |
2.98 |
2.34 |
Nitrogen content |
(mass %) |
0.22 |
0.15 |
0.18 |
0.20 |
0.18 |
0.18 |
Water content |
(volume %) |
0 |
0 |
0 |
0 |
0 |
0 |
Flush point |
(°C) |
111 |
105 |
108 |
102 |
95 |
110 |
Bicyclic aromatic content |
(volume %) |
14.9 |
42.9 |
32.7 |
10.9 |
8.4 |
9.8 |
CCAI |
|
839 |
814 |
829 |
814 |
797 |
832 |
Dry sludge |
(mg/100 mL) |
13 |
6 |
10 |
15 |
27 |
24 |
Fuel combustibility test |
|
|
|
|
|
|
|
Ignition delay |
(ms) |
9.4 |
10.2 |
9.9 |
9.1 |
8.2 |
10.1 |
Combustion time |
(ms) |
18.4 |
22.3 |
20.1 |
14.6 |
13.5 |
21.5 |
Thermogravimetry-differential thermal analysis |
|
|
|
|
|
|
|
Temperature at which the weight decreases by 10% |
(°C) |
306 |
285 |
298 |
311 |
289 |
315 |
Temperature at which the weight decreases by 50% |
(°C) |
512 |
490 |
501 |
509 |
499 |
523 |
Temperature at which the weight decreases by 90% |
(°C) |
702 |
662 |
673 |
683 |
679 |
693 |
Industrial Applicability
[0104] The C heavy oil composition of the present invention unlikely forms sludge and is
excellent in ignitability and combustibility. Therefore, the C heavy oil composition
of the present invention is very useful as fuel for external combustion devices such
as boilers, diesel engine devices of large ships and power generators, and gas turbine
devices.