U.S. patent application number 10/398508 was filed with the patent office on 2003-11-20 for dual purpose fuel for gasoline driven automobile and fuel cell system, and system for storage and/or supply thereof.
Invention is credited to Nagao, Masaki, Oyama, Koji, Sadakane, Osamu, Saitou, Kenichirou.
Application Number | 20030213728 10/398508 |
Document ID | / |
Family ID | 18790298 |
Filed Date | 2003-11-20 |
United States Patent
Application |
20030213728 |
Kind Code |
A1 |
Saitou, Kenichirou ; et
al. |
November 20, 2003 |
Dual purpose fuel for gasoline driven automobile and fuel cell
system, and system for storage and/or supply thereof
Abstract
The present invention provides a dual purpose fuel suitable for
an automotive spark ignition (SI) engine and a fuel cell system and
also provides a storage and/or supply system of said dual purpose
fuel. A dual purpose fuel for use in both an automotive spark
ignition (SI) engine and a fuel cell system wherein said fuel
comprises hydrocarbons of 50 ppm by mass or less of sulfur content;
30 vol. % or more of saturates; 50 vol. % or less of aromatics; and
35 vol. % or less of olefins; wherein the ratio of paraffin in said
saturates is 60 vol. % or more; the ratio of branched paraffin in
said paraffin is 70 vol. % or more; the density of said
hydrocarbons is 0.78 g/cm.sup.3 or less; the initial boiling point
in distillation is 24.degree. C. or higher and 80 .degree. C. or
lower, the 50 vol. % distillation temperature (T.sub.50) is
60.degree. C. or higher and 120.degree. C. or lower, the 90 vol. %
distillation temperature (T.sub.90) is 100.degree. C. or higher and
190.degree. C. or lower, the final boiling point in distillation is
130.degree. C. or higher and 230.degree. C. or lower; the Reid
vapor pressure of said hydrocarbons is 10 kPa or more and less than
100 kPa; and the research octane number of said hydrocarbons is
89.0 or more, and a storage and/or supply system of said dual
purpose fuel, wherein said dual purpose fuel is stored in a fuel
storage apparatus for an automotive spark ignition (SI) engine, and
fed, as demanded, to the automotive spark ignition (SI) engine or
to the fuel cell system from the fuel storage apparatus.
Inventors: |
Saitou, Kenichirou;
(Yokohama-shi, Kanagawa, JP) ; Nagao, Masaki;
(Yokohama-shi, Kanagawa, JP) ; Sadakane, Osamu;
(Yokohama-shi, Kanagawa, JP) ; Oyama, Koji;
(Yokohama-shi, Kanagawa, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
18790298 |
Appl. No.: |
10/398508 |
Filed: |
April 11, 2003 |
PCT Filed: |
October 11, 2001 |
PCT NO: |
PCT/JP01/08938 |
Current U.S.
Class: |
208/17 ;
208/18 |
Current CPC
Class: |
Y02E 60/50 20130101;
H01M 2250/20 20130101; Y02T 90/40 20130101; B60K 15/00 20130101;
H01M 8/04201 20130101; C10L 1/06 20130101 |
Class at
Publication: |
208/17 ;
208/18 |
International
Class: |
C10G 071/00; C10L
001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 11, 2000 |
JP |
2000-310315 |
Claims
1. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system wherein said fuel comprises
hydrocarbons of 50 ppm by mass or less of sulfur content; 30 vol. %
or more of saturates; 50 vol. % or less of aromatics; and 35 vol. %
or less of olefins; wherein the ratio of paraffin in said saturates
is 60 vol. % or more; the ratio of branched paraffin in said
paraffin is 70 vol. % or more; the density of said hydrocarbons is
0.78 g/cm.sup.3 or less; the initial boiling point in distillation
is 24.degree. C. or higher and 80.degree. C. or lower, the 50 vol.
% distillation temperature (T.sub.50) is 60.degree. C. or higher
and 120.degree. C. or lower, the 90 vol. % distillation temperature
(T.sub.90) is 100.degree. C. or higher and 190.degree. C. or lower,
the final boiling point in distillation is 130.degree. C. or higher
and 230.degree. C. or lower; the Reid vapor pressure of said
hydrocarbons is 10 kPa or more and less than 100 kPa; and the
research octane number of said hydrocarbons is 89.0 or more.
2. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system according to claim 1, wherein
said fuel exhibits total weighted demerits (TWD) of 40 or less
based on the driveability assessment method at the intermediate
temperature of CRC.
3. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system according to claim 1 or 2,
wherein said content of hydrocarbon compounds having four carbon
atoms is 15 vol. % or less, the content of hydrocarbon compounds
having five carbon atoms is 6 vol. % or more, the content of
hydrocarbon compounds having six carbon atoms is 5 vol. % or more,
a total content of hydrocarbon compounds having seven and eight
carbon atoms is 20 vol. % or more, and the content of hydrocarbon
compounds having ten or more carbon atoms is 20 vol. % or less.
4. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system according to any one of claims 1
to 3, wherein heat capacity of the fuel is 2.6 kJ/kg.degree. C. or
less at 15.degree. C. and 1 atm in liquid phase.
5. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system according to any one of claims 1
to 4, wherein heat of vaporization is 400 kJ/kg or less.
6. A dual purpose fuel for use in both an automotive spark ignition
(SI) engine and a fuel cell system according to any one of claims 1
to 5, wherein oxidation stability of the fuel is 240 minutes or
longer.
7. A storage and/or supply system of the dual purpose fuel, wherein
said dual purpose fuel according to any one of claims 1 to 6 is
stored in a fuel storage apparatus for an automotive spark ignition
(SI) engine, and fed, as demanded, to the automotive spark ignition
(SI) engine or to the fuel cell system from the fuel storage
apparatus.
8. A storage and/or supply system of the dual purpose fuel
according to claim 7, wherein said fuel storage apparatus is formed
of the existing storage apparatus for storing high-octane gasoline
or regular gasoline.
Description
TECHNICAL FIELD
[0001] The present invention relates to a dual purpose fuel for use
in both an automotive spark ignition (SI) engine and a fuel cell
system. The present invention also relates to a storage and/or
supply system of said dual purpose fuel.
BACKGROUND ART
[0002] Recently, with increasing awareness of the critical
situation of future global environments, it has been highly
expected to develop an energy supply system harmless to the global
environments. Especially urgently required are to reduce CO.sub.2
to prevent global warming and reduce harmful emissions such as THC
(unreacted hydrocarbons in an exhaust gas), NO.sub.x, PM
(particulate matter in an exhaust gas: soot, unburned high boiling
point and high molecular weight fuel and lubricating oil).
Practical examples of such a system are an automotive power system
to replace a conventional Otto/Diesel engine and a power generation
system to replace thermal power generation.
[0003] Hence, a fuel cell, which has high energy efficiency and
emits only H.sub.2O and CO.sub.2, has been regarded as a most
expectative system to respond to social requests. In order to
achieve such a system, it is necessary to develop not only the
hardware but also the optimum fuel.
[0004] Conventionally, as a fuel for a fuel cell system, hydrogen,
methanol, and hydrocarbons have been candidates.
[0005] As a fuel for a fuel cell system, hydrogen is advantageous
in a point that it does not require a reformer, however, because of
a gas phase at a normal temperature, it has difficulties in storage
and loading in a vehicle and special facilities are required for
its supply. Further, the risk of inflammation is high and
therefore, it has to be handled carefully.
[0006] Methanol is advantageous in a point that it is relatively
easy to reform, however power generation quantity per weight is low
and owing to its toxicity, handling has to be careful. Further, it
has a corrosive property, special facilities are required for its
storage and supply.
[0007] The hydrocarbon-based fuel is excellent in storability and
can easily be mounted on a vehicle, etc. In particular, since the
hydrocarbon-based fuel can be supplied by making use of the
existing service stations, the use of the hydrocarbon-based fuel is
deemed very advantageous in terms of infrastructure. However, since
the conventional gasoline includes sulfur content and additives,
and these sulfur content and additives are considered to give bad
influences on the catalyst to be used in the reforming reaction in
a fuel cell or on the electrodes of the fuel cell (in particular,
proton exchange membrane type fuel cell), it has been considered
impossible to use the conventional gasoline as a fuel for the fuel
cell.
[0008] Like this, a dual purpose fuel for use in both an automotive
spark ignition (SI) engine and a fuel cell system has not yet been
developed. In order to sufficiently utilize the performances for
use in an automotive spark ignition (SI) engine and a fuel cell
system, as a fuel for a fuel cell system, the following are
required: power generation quantity per weight is high; power
generation quantity per CO.sub.2 emission is high; a fuel
consumption is low in a fuel cell system as a whole; deterioration
of a fuel cell system comprising such as a reforming catalyst, a
water gas shift reaction catalyst, a carbon monoxide conversion
catalyst, fuel cell stacks and the like is scarce to keep the
initial performances for a long duration; a starting time for the
system is short; and storage stability and handling easiness are
excellent.
[0009] Incidentally, in a fuel cell system, it is required to keep
a fuel and a reforming catalyst at a proper temperature, the net
power generation quantity of the entire fuel cell system is
equivalent to the value calculated by subtracting the energy
necessary for keeping the temperature (the energy for keeping
balance endothermic and exothermic reaction following the
preheating energy) from the actual power generation quantity.
Consequently, if the temperature for the reforming is lower, the
energy for preheating is low and that is therefore advantageous and
further the system starting time is advantageously shortened. In
addition, it is also necessary that the energy for preheating per
fuel weight is low. If the preheating is insufficient, unreacted
hydrocarbon (THC) in an exhaust gas increases and it results in not
only decrease of the power generation quantity per weight but also
possibility of becoming causes of air pollution. To say conversely,
when some kind of fuels are reformed by the same reformer and the
same temperature, it is more advantageous that THC in an exhaust
gas is lower and the conversion efficiency to hydrogen is
higher.
[0010] In the meantime, in the existing service stations and oil
terminals, there are disposed a plurality of fuel storage tanks
which are respectively designed to be filled with a specific kind
of fuel product such as high-octane gasoline, regular gasoline, gas
oil, kerosene, etc. Therefore, if it is desired to additionally
deal with a hydrocarbon-based fuel to be used for the fuel cell, an
additional tank to be exclusively designed for storing this
hydrocarbon-based fuel is required to be installed in the service
stations or the oil terminals, thus necessitating the rearrangement
more or less in terms of infrastructure if the aforementioned
existing fuel products are also to be concurrently dealt with by
the same service stations or oil terminals.
[0011] The present invention, taking such situation into
consideration, aims to provide a dual purpose fuel for use in both
an automotive spark ignition (SI) engine and a fuel cell system
satisfying the above-described requirements in good balance. The
present invention also aims to provide a storage and/or supply
system of said dual purpose fuel.
DISCLOSURE OF THE INVENTION
[0012] Inventors of the present invention have extensively
investigated to solve the above-described problems and found that a
fuel comprising hydrocarbon compounds with specific compositions
and properties is suitable for a dual purpose fuel for an
automotive spark ignition (SI) engine and a fuel cell system.
[0013] That is, the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system according to the
present invention comprises:
[0014] (1) hydrocarbons comprising 50 ppm by mass or less of sulfur
content; 30 vol. % or more of saturates; 50 vol. % or less of
aromatics; and 35 vol. % or less of olefins; wherein the ratio of
paraffin in said saturates is 60 vol. % or more; the ratio of
branched paraffin in said paraffin is 70 vol. % or more; the
density of said hydrocarbons is 0.78 g/cm.sup.3 or less; the
initial boiling point in distillation is 24.degree. C. or higher
and 80.degree. C. or lower, the 50 vol. % distillation temperature
(T.sub.50) is 60.degree. C. or higher and 120.degree. C. or lower,
the 90 vol. % distillation temperature (T.sub.90) is 100.degree. C.
or higher and 190.degree. C. or lower, the final boiling point in
distillation is 130.degree. C. or higher and 230.degree. C. or
lower; the Reid vapor pressure of said hydrocarbons is 10 kPa or
more and less than 100 kPa; and the research octane number of said
hydrocarbons is 89.0 or more.
[0015] It is more preferable that the fuel comprising the
aforementioned specific composition and properties is formulated so
as to satisfy the following additional requirements:
[0016] (2) the fuel exhibits total weighted demerits (TWD) of 40 or
less based on the driveability assessment method at the
intermediate temperature of CRC;
[0017] (3) a content of hydrocarbon compounds having four carbon
atoms is 15 vol. % or less, a content of hydrocarbon compounds
having five carbon atoms is 5 vol. % or more, a content of
hydrocarbon compounds having six carbon atoms is 5 vol. % or more,
a total content of hydrocarbon compounds having seven and eight
carbon atoms is 20 vol. % or more, and a total content of
hydrocarbon compounds having ten or more carbon atoms is 20 vol. %
or less;
[0018] (4) heat capacity of the fuel is 2.6 kJ/kg.degree. C. or
less at 15.degree. C. and 1 atm in liquid phase;
[0019] (5) heat of vaporization is 400 kJ/kg or less;
[0020] (6) oxidation stability of the fuel is 240 minutes or
longer.
[0021] Further, the storage and/or supply system of said dual
purpose fuel for an automotive spark ignition (SI) engine and a
fuel cell system according to the present invention is featured in
that:
[0022] (7) the dual purpose fuel which is defined in any one of the
aforementioned items (1) to (6) is stored in a fuel storage
apparatus for an automotive spark ignition (SI) engine, and fed, as
demanded, to the automotive spark ignition (SI) engine or to the
fuel cell system from this fuel storage apparatus.
[0023] Further, the storage and/or supply system may be constructed
so as to satisfy the following additional requirements:
[0024] (8) the fuel storage apparatus for an automotive spark
ignition (SI) engine is formed of the existing storage apparatus
for storing high-octane gasoline or regular gasoline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 shows a flow chart of a steam reforming type fuel
cell system used for evaluation of a dual purpose fuel for an
automotive spark ignition (SI) engine and a fuel cell system of the
invention.
[0026] FIG. 2 is a flow chart of a partial oxidation type fuel cell
system used for evaluation of a dual purpose fuel for an automotive
spark ignition (SI) engine and a fuel cell system of the
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Hereinafter, the contents of the invention will be described
further in detail.
[0028] In the present invention, the hydrocarbon compounds with
specific compositions and properties are as follows.
[0029] The content of sulfur in a dual purpose fuel for an
automotive spark ignition (SI) engine and a fuel cell system of the
invention is, when used in a fuel for a fuel cell system, 50 ppm by
mass or less, more preferably 30 ppm by mass or less, more
preferably 10 ppm by mass or less, further more preferably 1 ppm by
mass or less, and most preferably 0.1 ppm by mass or less, because
deterioration of a fuel cell system comprising such as a reforming
catalyst, a water gas shift reaction catalyst, a carbon monoxide
removal catalyst, fuel cell stacks, and the like can be suppressed
to low and the initial performances can be maintained for a long
duration.
[0030] Here, sulfur means sulfur measured by JIS K 2541, "Crude Oil
and Petroleum Products-Determination of sulfur content", in case of
1 ppm by mass or more and means sulfur measured by ASTM D4045-96,
"Standard Test Method for Sulfur in Petroleum Products by
Hydrogenolysis and Rateometric Colorimetry" in the case of less
than 1 ppm by mass.
[0031] In the dual purpose fuel for an automotive spark ignition
(SI) engine and a fuel cell system of the invention, with respect
to the respective contents of saturates, aromatics and olefins, the
saturates (V (S)) is 30 vol. % or more, aromatics (V (Ar)) is 50
vol. % or less and olefins (V (O)) is 35 vol. % or less,
respectively. Hereinafter, these compounds will separately be
described.
[0032] In view of a high power generation quantity per weight, a
high power generation quantity per CO.sub.2 emission, a low fuel
consumption of a fuel cell system as a whole, small THC in an
exhaust gas, and a short starting time of the system, when used in
a fuel for a fuel cell system, and in view of preventing the coking
of gasoline inside the injector, minimizing the smoking of the
plugs, inhibiting the generation of ozone from the exhaust gas, and
preventing the generation of soot, when used in an automotive spark
ignition (SI) engine, V (S) is 30 vol. % or more, preferably 40
vol. % or more, more preferably 50 vol. % or more, further more
preferably 60 vol. % or more, much more preferably 70 vol. % or
more, much further more preferably 80 vol. % or more, still further
more preferably 90 vol. % or more, and most preferably 95 vol. % or
more.
[0033] In view of a high power generation quantity per weight, a
high power generation quantity per CO.sub.2 emission, a low fuel
consumption of a fuel cell system as a whole, small deterioration
of a reforming catalyst to maintain the initial performances for a
long duration, small THC in an exhaust gas, and a short starting
time of the system, when used in a fuel for a fuel cell system, and
in view of preventing the coking of gasoline inside the injector,
minimizing the smoking of the plugs, inhibiting the generation of
ozone from the exhaust gas, and preventing the generation of soot,
when used in an automotive spark ignition (SI) engine, V (Ar) is 50
vol. % or less, preferably 45 vol. % or less, more preferably 40
vol. % or less, further more preferably 35 vol. % or less, much
more preferably 30 vol. % or less, much further more preferably 20
vol. % or less, still further more preferably 10 vol. % or less,
and most preferably 5 vol. % or less.
[0034] In the dual purpose fuel for an automotive spark ignition
(SI) engine and a fuel cell system of the invention, it is most
preferable to satisfy the above-described preferable ranges of
sulfur and aromatics since deterioration of a reforming catalyst
can be suppressed to low and the initial performances can be
maintained for a long duration.
[0035] In view of a high power generation quantity per weight, a
high power generation quantity per CO.sub.2 emission, a low fuel
consumption of a fuel cell system as a whole, small deterioration
of a reforming catalyst to maintain the initial performances for a
long duration and a good storage stability, when used in a fuel for
a fuel cell system, and in view of preventing the coking of
gasoline inside the injector, minimizing the smoking of the plugs,
inhibiting the generation of ozone from the exhaust gas, minimizing
the benzene concentration in the exhaust gas, and preventing the
generation of soot, when used in an automotive spark ignition (SI)
engine, V (O) is 35 vol. % or less, preferably 25 vol. % or less,
more preferably 20 vol. % or less, further more preferably 15 vol.
% or less, and most preferably 10 vol. % or less.
[0036] The values of the above-described V (S), V (O), and V (Ar)
are all measured value according to the fluorescent indicator
adsorption method of JIS K 2536, "Liquid petroleum products-Testing
method of components".
[0037] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, in
view of a high power generation quantity per weight, a high power
generation quantity per CO.sub.2 emission and the like, the ratio
of paraffins in saturates of a fuel is 60 vol. % or more,
preferably 65 vol. % or more, more preferably 70 vol. % or more,
further more preferably 75 vol. % or more, much more preferably 80
vol. % or more, much further more preferably 85 vol. % or more,
particularly preferably 90 vol. % or more, and most preferably 95
vol. % or more.
[0038] Further, in view of a high power generation quantity per
weight, a high power generation quantity per CO.sub.2 emission, a
low fuel consumption of a fuel cell system as a whole, small THC in
an exhaust gas, and a short starting time of the system, when used
in a fuel for a fuel cell system, and in view of improving the
octane value, when used in an automotive spark ignition (SI)
engine, the ratio of branched paraffins in the above-described
paraffins is 70 vol. % or more, preferably 75 vol. % or more, and
most preferably 80 vol. % or more.
[0039] The above-described saturates and paraffins are values
quantitatively measured by the following gas chromatography. That
is, the values are measured in conditions: using capillary columns
of methyl silicon for columns; using helium or nitrogen as a
carrier gas; a hydrogen ionization detector (FID) as a detector;
the column length of 25 to 50 m; the carrier gas flow rate of 0.5
to 1.5 ml/min, the split ratio of (1:50) to (1:250); the injection
inlet temperature of 150 to 250.degree. C.; the initial column
temperature of -10 to 10.degree. C.; the final column temperature
of 150 to 250.degree. C., and the detector temperature of 150 to
250.degree. C.
[0040] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, in
view of a high power generation quantity per weight, a low fuel
consumption of a fuel cell system as a whole, small THC in an
exhaust gas, and a short starting time of the system, when used in
a fuel for a fuel cell system, the density of a fuel is 0.78
g/cm.sup.3 or less. Here, the density means the density measured
according to JIS K 2249, "Crude petroleum and petroleum
products--Determination of density and petroleum measurement tables
based on a reference temperature (15.degree. C.)".
[0041] The dual purpose fuel for an automotive spark ignition (SI)
engine and a fuel cell system of the invention has initial boiling
point (initial boiling point 0) in distillation of 24.degree. C. or
higher and 80.degree. C. or lower, preferably 24.degree. C. or
higher and 50.degree. C. or lower. The 50 vol. % distillation
temperature (T.sub.50) is 60.degree. C. or higher and 120.degree.
C. or lower, preferably 75.degree. C. or higher and 110.degree. C.
or lower, and more preferably 78.degree. C. or higher and
100.degree. C. or lower. The 90 vol. % distillation temperature
(T.sub.90) is 100.degree. C. or higher and 190.degree. C. or lower
and preferably 100.degree. C. or lower and 170.degree. C. or lower.
The final boiling point in distillation is 130.degree. C. or higher
and 230.degree. C. or lower and preferably 130.degree. C. or higher
and 220.degree. C. or lower.
[0042] If the initial boiling point (initial boiling point 0) in
distillation is low, when used in a fuel for a fuel cell system,
the fuel is highly inflammable and an evaporative gas (THC) is easy
to be generated and there is a problem to handle the fuel, and when
used in an automotive spark ignition (SI) engine, there is a
possibility to deteriorate driving performance at a high
temperature.
[0043] Similarly regarding to the 50 vol. % distillation
temperature (T.sub.50), if it is less than the above-described
restricted value, when used in a fuel for a fuel cell system, the
fuel is highly inflammable and an evaporative gas (THC) is easy to
be generated and there is a problem to handle the fuel, and when
used in an automotive spark ignition (SI) engine, there is a
possibility to cause troubles in driving performance.
[0044] On the other hand, the 90 vol. % distillation temperature
(T.sub.90) and the final boiling point in distillation are
determined, when used in a fuel for a fuel cell system, in view of
a high power generation quantity per weight, a high power
generation quantity per CO.sub.2 emission, a low fuel consumption
of a fuel cell system as a whole, a low THC in an exhaust gas,
short starting time of a system, and the like. When used in an
automotive spark ignition (SI) engine, if the 90 vol. %
distillation temperature (T.sub.90) and the final boiling point in
distillation are high, there are possibilities to deteriorate
driving performance and to increase the exhaust gases. Further, the
90 vol. % distillation temperature (T.sub.90) and the final boiling
point in distillation are also determined in view of diluting
engine oils by gasoline and inhibiting generation of sludge.
[0045] Incidentally, the above-described initial boiling point
(initial boiling point 0) in distillation, the 50 vol. %
distillation temperature (T.sub.50), the 90 vol. % distillation
temperature (T.sub.90), and the final boiling point in distillation
are distillation properties measured by JIS K 2254, "Petroleum
products--Determination of distillation characteristics".
[0046] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, when
used in a fuel for a fuel cell system, in view of a high power
generation quantity per weight, a low fuel consumption of a fuel
cell system as a whole, and the like, and when used in an
automotive spark ignition (SI) engine, although the vapor pressure
is not particularly restricted, in view of preventing the coking of
gasoline inside the injector, minimizing the amounts of evaporating
gas (evapo-emission), and being convenient to handle in the
flashing point and the like, the Reid vapor pressure (RVP) of a
fuel is 10 kPa or more and less than 100 kPa, preferably 20 kPa or
more and less than 90 kPa, more preferably 50 kPa or more and less
than 75 kPa.
[0047] Here, the Reid vapor pressure (RVP) means the vapor pressure
(Reid vapor pressure (RVP)) measured by JIS K 2258, "Testing Method
for Vapor Pressure of Crude Oil and Products (Reid Method)".
[0048] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, the
research octane number (RON, the octane number by research method)
is 89.0 or more in view of enhancing anti-knocking property, when
used in an automotive spark ignition (SI) engine. Here, the octane
number by research method (RON) means the research method octane
number measured by JIS K 2280, "Petroleum
products-Fuels-Determination of octane number, cetane number and
calculation of cetane number index".
[0049] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, with
respect to the assessment as a fuel for an automotive spark
ignition (SI) engine, the total weighted demerits (TWD) based on
the assessment method for driveability at the intermediate
temperature (25.degree. C.) of CRC should preferably be 40 or less,
more preferably 30 or less.
[0050] By the way, the assessment method for driveability of CRC
used herein is a method wherein an automobile is driven in
accordance with the driving pattern based on the CRC method
described in "CRC Report No. 483", and the driveability of the fuel
is assessed. The total weighted demerits (TWD) are determined in
such a manner that, based on a demerit score to be given to any one
of the phenomena described in the demerit items shown in Table 1 by
referring to the malfunction severity ratings described in Table 2
and also based on a factor prescribed for each of the demerit items
which are described in Table 3, a value of "the demerit
score".times."the factor" is calculated. This calculation is
performed on all of the items stipulated therein, and all of the
results are finally summarized, thus evaluating the driveability of
the fuel. The higher the TWD is, the larger the problems to be
encountered as the fuel is actually used as gasoline.
1TABLE 1 [Demerit items and the definition terms] Demerit items
Definition of terms Start Time Start-up the engine using
manufacturers recommended throttle position, timed in seconds from
initial starter engagement to engine firing. Idle Roughness Any
evaluation of a degree of vehicle smoothness while the engine is
idling. Stall Any occasion during a test that the engine stops with
the ignition on. Stumble A short, sharp reduction in acceleration
rate experienced under acceleration Surge A continued or transient
condition of fluctuations in power, experienced as changes in
acceleration rate which are short or long, cyclic or random, and
occurring at any speed and/or load. Hesitation A temporary lack of
initial response to changes of throttle position to increase
acceleration rate. Backfire An explosion in the induction or
exhaust system.
[0051]
2TABLE 2 [Demerit Score] Malfunction Severity Ratings Score Trace:
A level of malfunction severity that is 1 only discernible to a
test driver. Moderate: A level of malfunction severity judged 2 by
a rater to be probably noticeable to the average driver. Heavy: A
level of malfunction severity that is 4 pronounced and judged to be
obvious to any driver.
[0052]
3TABLE 3 [Factor when any defectiveness is found in assessed
demerit items] Demerit items Factor Start time and idle roughness 1
Surge 4 Stumble, hesitation and backfire 6 Stall (during idling) 8
Stall (during driving) 32
[0053] Further, the amounts of hydrocarbon compounds having carbon
numbers of 4, 5 and 6 used in the invention are not particularly
restricted, however, the following compounds are preferable.
[0054] The content of hydrocarbon compounds having a carbon number
of 4 (V (C.sub.4)) shows the content of hydrocarbon compounds
having 4 carbon atoms on the basis of the whole fuel and is
required to be 15 vol. % or less in view of the evaporative gas
(evapo-emission) can be suppressed to low and the handling property
is good in respect of inflammability or the like and preferably 10
vol. % or less.
[0055] The content of hydrocarbon compounds having a carbon number
of 5 (V (C.sub.5)) shows the content of hydrocarbon compounds
having 5 carbon atoms on the basis of the whole fuel and is
required to be 5 vol. % or more in view of a high power generation
quantity per weight, a high power generation quantity per CO.sub.2
emission, and a low fuel consumption of a fuel cell system as a
whole and preferably 10 vol. % or more, more preferably 15 vol. %
or more, further more preferably 20 vol. % or more.
[0056] The content of hydrocarbon compounds having a carbon number
of 6 (V (C.sub.6)) shows the content of hydrocarbon compounds
having 6 carbon atoms on the basis of the whole fuel and is
required to be 5 vol. % or more in view of a high power generation
quantity per weight, a high power generation quantity per CO.sub.2
emission, and a low fuel consumption of a fuel cell system as a
whole and preferably 10 vol. % or more, more preferably 15 vol. %
or more, further more preferably 20 vol. % or more.
[0057] The content of hydrocarbon compounds having carbon numbers
of 7 and 8 (V (C.sub.7+C.sub.8)) in total shows the content of
hydrocarbon compounds having 7 carbon atoms and 8 carbon atoms in
total on the basis of the whole fuel and is required to be 20 vol.
% or more in view of a high power generation quantity per weight, a
high power generation quantity per CO.sub.2 emission, and a low
fuel consumption of a fuel cell system as a whole and preferably 25
vol. % or more, more preferably 35 vol. % or more, and further more
preferably 40 vol. % or more.
[0058] Further, in the invention, the content of hydrocarbons
having carbon numbers of 10 or more is not particularly restricted,
however, in view of a high power generation quantity per CO.sub.2
emission, a low fuel consumption of a fuel cell system as a whole,
and small deterioration of a reforming catalyst to maintain initial
performances for a long duration, the total content of hydrocarbon
compounds having carbon numbers of 10 or more (V (C.sub.10+)) on
the basis of the whole fuel is preferably 20 vol. % or less, more
preferably 15 vol. % or less, further more preferably 10 vol. % or
less.
[0059] Incidentally, the above-described V (C.sub.4), V (C.sub.5),
V (C.sub.6), V (C.sub.7+C.sub.8), and V (C.sub.10+) are values
quantitatively measured by the following gas chromatography. That
is, these values are measured in conditions: using capillary
columns of methyl silicon for columns; using helium or nitrogen as
a carrier gas; using a hydrogen ionization detector (FID) as a
detector; the column length of 25 to 50 m; the carrier gas flow
rate of 0.5 to 1.5 ml/min, the split ratio of (1:50) to (1:250);
the injection inlet temperature of 150 to 250.degree. C.; the
initial column temperature of -10 to 10.degree. C.; the final
column temperature of 150 to 250.degree. C., and the detector
temperature of 150 to 250.degree. C.
[0060] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, the
heat capacity of a fuel is not particularly restricted, however,
the heat capacity is preferably 2.6 kJ/kg.multidot..degree. C. or
less at 15.degree. C. and 1 atm in liquid phase in view of a low
fuel consumption of a fuel cell system as a whole.
[0061] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, the
heat of vaporization of a fuel is not particularly restricted, the
heat of vaporization is preferably 400 kJ/kg or less because of a
low fuel consumption of a fuel cell system as a whole.
[0062] Those heat capacity and heat of vaporization can be
calculated from the contents of respective components
quantitatively measured by the above-described gas chromatography
and the numeric values per unit weight of the respective components
disclosed in "Technical Data Book--Petroleum Refining", Vol. 1,
Chap. 1, General Data, Table 1C1.
[0063] Further, in the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention, the
oxidation stability of a fuel is not particularly restricted,
however, it is preferably 240 minutes or longer in view of storage
stability. Here, the oxidation stability is the oxidation stability
measured according to JIS K 2287, "Testing Method for Oxidation
Stability of Gasoline (Induction Period Method)".
[0064] A production method of the dual purpose fuel for an
automotive spark ignition (SI) engine and a fuel cell system of the
invention is not particularly restricted. As a practical method,
for example, the fuel can be prepared by blending one or more
following hydrocarbon base materials; desulfurized whole-range
naphtha obtained by desulfurization of naphtha fraction obtained by
the atmospheric distillation of crude oil, desulfurized light
naphtha, which is light fractions, obtained by further distillation
of the desulfurized whole-range naphtha, desulfurized heavy
naphtha, which is heavy fractions, obtained by further distillation
of the desulfurized whole-range naphtha, light distillate of
reformate, which is light fractions, obtained by further
distillation of reformate obtained by reforming the desulfurized
heavy naphtha, middle to heavy distillate of reformate, which is
middle to heavy distillate fractions, obtained by further
distillation of reformate obtained by reforming the desulfurized
heavy naphtha, heavy distillate of reformate, which is heavy
distillate fractions, obtained by further distillation of reformate
obtained by reforming the desulfurized heavy naphtha,
sulfolane-raffinate which is residue after extraction of aromatics
by subjecting middle to heavy distillate of reformate to the
sulfolane process, catalytic cracked gasoline obtained by
subjecting heavy oil to the fluid catalytic cracking process, light
catalytic cracked gasoline, which is light fractions, obtained by
distillation of the catalytic cracked gasoline, alkylate, which is
gasoline fractions, obtained by subjecting butane-butene fractions
to the alkylation process, desulfurized alkylate obtained by
desulfurization of alkylate, low-sulfur alkylate based on
desulfurized butane-butene, isomerate, which is gasoline fractions,
obtained by subjecting the desulfurized heavy naphtha to the
isomerization process, "GTL (Gas to Liquids)" naphtha, which is
naphtha fractions of synthesis fuel, obtained by synthesis,
cracking, isomerization or the like after cracking natural gas,
coal or the like to carbon monoxide and hydrogen, LPG, desulfurized
LPG obtained by desulfurizing LPG, MTBE, and the like. The fuel can
also be produced by desulfurizing by hydrotreating or adsorption
after mixing one or more types of the above base materials.
[0065] If sulfur content is desired to be further reduced in the
aforementioned fuel, for example, if the sulfur content in the fuel
is desired to be reduced to 50 ppm by mass or less, especially when
the sulfur content of the fuel to be obtained by the aforementioned
method is required to be further reduced and especially when the
fuel is a catalytic cracked gasoline, the sulfur content should be
removed from the catalytic cracked gasoline by making use of a
hydrodesulfurization process and the like. Alternatively, the
sulfur content in crude oil of a fluid catalytic cracking process
(FCC) for manufacturing the catalytic cracked gasoline should be
reduced to a suitable degree as required. When the
hydrodesulfurization process is to be used for the desulfurization,
the ordinary hydrodesulfurization method used now in an oil
refinery will lead to a decrease of octane value due to the
concurrent generation of a hydrogenation reaction of olefin
components. Therefore, it is more preferably to use a method which
is capable of suppressing the lowering of the octane number as
described for example in Japanese Patent Application Laid-Open
Gazette (Unexamined Publication) No. H7-157774, U.S. Pat. No.
5,352,354 or U.S. Pat. No. 6,013,598.
[0066] Among them, preferable materials as the base materials for
the production of the dual purpose fuel for an automotive spark
ignition (SI) engine and a fuel cell system of the invention are
desulfurized light naphtha, desulfurized whole-range naphtha,
isomerate, alkylates, desulfurized alkylates obtained by
desulfurizing alkylates, low sulfur alkylates based on desulfurized
butane-butene fractions, sulfolane-raffinate, light catalytic
cracked gasoline, light distillate of reformate, middle to heavy
distillate of reformate, desulfurized light distillate of catalytic
cracked gasoline obtained by desulfurizing a light distillate of
catalytic cracked gasoline, GTL naphtha, LPG, desulfurized LPG
obtained by desulfurizing LPG, MTBE and the like.
[0067] The dual purpose fuel of the invention may comprise
additives such as dyes for identification, oxidation inhibitors for
improvement of oxidation stability, metal deactivators, corrosion
inhibitors for corrosion prevention, detergents for keeping
cleanness of a fuel system, lubricity improvers for improvement of
lubricating property and the like.
[0068] However, since a reforming catalyst is to be scarcely
deteriorated and the initial performances are to be maintained for
a long duration, the amount of dyes is preferably 10 ppm or less
and more preferably 5 ppm or less. For the same reasons, the amount
of oxidation inhibitors is preferably 300 ppm or less, more
preferably 200 ppm or less, further more preferably 100 ppm or
less, and most preferably 10 ppm or less. For the same reasons, the
amount of metal deactivators is preferably 50 ppm or less, more
preferably 30 ppm or less, further more preferably 10 ppm or less,
and most preferably 5 ppm or less. Further, similarly since a
reforming catalyst is to be scarcely deteriorated and the initial
performances are to be maintained for a long duration, the amount
of corrosion inhibitors is preferably 50 ppm or less, more
preferably 30 ppm or less, further more preferably 10 ppm or less,
and most preferably 5 ppm or less. For the same reasons, the amount
of detergents is preferably 300 ppm or less, more preferably 200
ppm or less, and most preferably 100 ppm or less. For the same
reasons, the amount of lubricity improvers is preferably 300 ppm or
less, more preferably 200 ppm or less, and most preferably 100 ppm
or less.
[0069] A fuel of the invention is to be used as a dual purpose fuel
for an automotive spark ignition (SI) engine and a fuel cell
system. As for the automotive spark ignition (SI) engine defined in
the invention, a kind of automobile is not particularly restricted.
Further, a fuel cell system mentioned herein comprises a reformer
for a fuel, a carbon monoxide conversion apparatus, fuel cells and
the like, however, a fuel of the invention may be suitable for any
fuel cell system.
[0070] The reformer is an apparatus for obtaining hydrogen, by
reforming a fuel. Practical examples of the reformer are:
[0071] (1) a steam reforming type reformer for obtaining products
of mainly hydrogen by treating a heated and vaporized fuel and
steam with a catalyst such as copper, nickel, platinum, ruthenium
and the like;
[0072] (2) a partial oxidation type reformer for obtaining products
of mainly hydrogen by treating a heated and vaporized fuel and air
with or without a catalyst such as copper, nickel, platinum,
ruthenium and the like; and
[0073] (3) an auto thermal reforming type reformer for obtaining
products of mainly hydrogen by treating a heated and vaporized
fuel, steam and air, which carries out the partial oxidation of (2)
in the prior stage and carries out the steam reforming of (1) in
the posterior stage while using the generated heat of the partial
oxidation reaction with a catalyst such as copper, nickel,
platinum, ruthenium and the like.
[0074] The carbon monoxide conversion apparatus is an apparatus for
removing carbon monoxide which is contained in a gas produced by
the above-described reformer and becomes a catalyst poison in a
fuel cell and practical examples thereof are:
[0075] (1) a water gas shift reactor for obtaining carbon dioxide
and hydrogen as products from carbon monoxide and steam by reacting
a reformed gas and steam in the presence of a catalyst of such as
copper, nickel, platinum, ruthenium and the like; and
[0076] (2) a preferential oxidation reactor for converting carbon
monoxide into carbon dioxide by reacting a reformed gas and
compressed air in the presence of a catalyst of such as platinum,
ruthenium and the like, and these are used singly or jointly.
[0077] As a fuel cell, practical examples are a proton exchange
membrane type fuel cell (PEFC), a phosphoric acid type fuel cell
(PAFC), a molten carbonate type fuel cell (MCFC), a solid oxide
type fell cell (SOFC) and the like.
[0078] As for the examples of the fuel cell system to which the
present invention can be applied, they include a stationary fuel
cell system which is mainly designed to be used for the generation
of electrical energy, a movable fuel cell system which is mainly
designed to be used as a power source for a vehicle (so-called fuel
cell powered vehicle), etc.
[0079] In the case of the stationary fuel cell system, it is
possible to use a cogeneration system for effectively utilizing the
heat generated in the fuel cell system. Therefore, this stationary
fuel cell system is now widely studied to make it into a big size
so as to enable it to be utilized in a factory, or into a small
size so as to enable it to be utilized at home.
[0080] With respect to the kind of the fuel cell system to which
this dual purpose fuel can be fed, there is not any particular
limitation, i.e. they may be either a fuel cell powered vehicle or
a stationary fuel cell system. As for the stationary fuel cell
system, it is particularly useful if the stationary fuel cell
system is installed at a service station.
[0081] Further, it is not necessary to provide a service station
with a fuel tank which is exclusively designed for use in a
stationary fuel cell system. Namely, this dual purpose fuel can be
introduced into the conventional gasoline tank, thereby enabling
the fuel to be supplied not only for an automotive spark ignition
(SI) engine but also for a fuel cell system.
EXAMPLES
[0082] The properties of base materials used for the respective
fuels for examples and comparative examples are shown in Table
4.
4TABLE 4 middle to desulfurized light heavy whole- desulfurized
desulfurized distillate distillate distillate range light heavy of
of of naphtha naphtha naphtha reformate reformate reformate *1 *2
*3 *4 *5 *6 sulfur mass % 0.3 0.1 0.2 0.5 0.2 0.4 hydrocarbon ratio
carbon number: C.sub.4 vol. % 1.6 5.4 0.0 1.3 18.0 0.0 carbon
number: C.sub.5 vol. % 12.5 42.2 0.3 9.1 49.9 0.0 carbon number:
C.sub.6 vol. % 19.7 49.2 7.2 18.9 31.9 0.6 carbon number: C.sub.7
vol. % 20.9 3.1 28.1 28.3 0.2 36.2 carbon number: C.sub.8 vol. %
24.3 0.1 33.1 32.2 0.0 47.9 carbon number: C.sub.9 vol. % 18.5 0.0
26.4 8.9 0.0 13.3 carbon number: C.sub.10+ vol. % 2.5 0.0 4.9 1.3
0.0 2.0 composition saturates vol. % 92.8 98.9 91.7 21.9 97.2 4.5
olefins vol. % 0.0 0.0 0.0 1.7 1.8 0.1 aromatics vol. % 6.6 1.1 8.3
76.4 1.1 95.4 paraffins in saturates vol. % 85.5 92.6 79.0 98.1
99.0 98.4 branched paraffins in vol. % 44.4 37.2 48.6 63.7 62.9
48.4 paraffins oxygen mass % 0.0 0.0 0.0 0.0 0.0 0.0 distillation
initial boiling point .degree. C. 35.0 28.0 71.5 30.5 22.0 102.5
10% point .degree. C. 55.0 40.5 92.5 59.0 26.0 117.5 30% point
.degree. C. 73.5 47.5 100.5 91.5 32.5 123.0 50% point .degree. C.
91.5 51.5 111.5 110.5 40.5 129.5 70% point .degree. C. 112.5 57.5
127.0 126.5 47.5 137.5 90% point .degree. C. 134.5 68.5 135.5 145.5
54.0 151.0 final boiling point .degree. C. 155.5 78.5 157.5 175.5
66.0 191.5 heat capacity (liquid) kJ/kg .multidot. .degree. C.
2.105 2.197 2.038 1.812 2.230 1.715 heat capacity (gas) kJ/kg
.multidot. .degree. C. 1.523 1.569 1.506 1.218 1.586 1.172 heat of
vaporization kJ/kg 317.2 344.4 304.2 349.8 348.1 344.4 RVP kPa 66.9
95.6 19.5 62.5 127.5 7.0 research octane number 63.4 71.8 53.2
101.5 78.2 111.5 oxidation stability min. >1440 >1440
>1440 >1440 >1440 >1440 density g/cm.sup.3 0.7085
0.6564 0.7331 0.8055 0.6487 0.8621 net heat of combustion kJ/kg
44225 44819 43940 41509 44974 41024 heavy light heavy distillate
catalytic catalytic catalytic low of sulfolane cracked cracked
cracked sulfur reformate raffinate gasoline gasoline gasoline
alkylate *7 *8 *9 *10 *11 *12 sulfur mass % 0.3 0.4 80 7 110 5
hydrocarbon ratio carbon number: C.sub.4 vol. % 0.0 0.7 7.3 13.4
0.0 8.6 carbon number: C.sub.5 vol. % 0.0 4.4 25.1 47.1 0.2 3.2
carbon number: C.sub.6 vol. % 0.0 46.2 20.1 29.2 7.2 2.8 carbon
number: C.sub.7 vol. % 0.0 47.6 18.1 8.8 23.5 2.5 carbon number:
C.sub.8 vol. % 0.0 1.1 13.7 1.4 22.7 79.8 carbon number: C.sub.9
vol. % 68.3 0.0 11.4 0.0 21.3 1.1 carbon number: C.sub.10+ vol. %
31.7 0.0 4.3 0.0 25.1 2.0 composition saturates vol. % 0.4 95.5
47.2 45.0 33.0 99.8 olefins vol. % 0.0 4.4 39.4 53.7 39.2 0.1
aromatics vol. % 99.6 0.1 13.4 1.3 27.8 0.1 paraffins in saturates
vol. % 97.4 98.2 85.6 93.5 76.4 100.0 branched paraffins in vol. %
86.8 72.5 88.6 86.1 88.5 91.3 paraffins oxygen mass % 0.0 0.0 0.0
0.0 0.0 0.0 distillation initial boiling point .degree. C. 162.5
66.0 31.5 24.5 108.0 31.0 10% point .degree. C. 164.0 72.5 51.5
32.5 119.0 71.5 30% point .degree. C. 165.5 75.5 77.0 38.5 126.5
98.5 50% point .degree. C. 167.5 79.5 111.5 45.0 135.0 105.5 70%
point .degree. C. 171.0 86.0 150.5 53.5 148.0 110.0 90% point
.degree. C. 190.5 98.5 189.0 69.5 167.0 122.5 final boiling point
.degree. C. 270.0 126.0 216.5 93.5 183.5 181.5 heat capacity
(liquid) kJ/kg .multidot. .degree. C. 1.699 2.155 2.063 2.159 1.946
2.071 heat capacity (gas) kJ/kg .multidot. .degree. C. 1.238 1.573
1.464 1.519 1.389 1.590 heat of vaporization kJ/kg 309.6 318.8
333.2 353.2 311.2 289.8 RVP kPa 0.1 29.9 62.5 115.3 12.0 58.5
research octane number 118.0 56.9 92.3 95.5 88.3 95.6 oxidation
stability min. >1440 >1440 210 150 200 >1440 density
g/cm.sup.3 0.8883 0.6821 0.7388 0.6601 0.7798 0.6955 net heat of
combustion kJ/kg 41250 44585 43903 44589 42949 44888 low sulfur
desulfurized GTL desulfurized alkylate alkylate isomerate naphtha
LPG *13 *14 *15 *16 LPG *17 sulfur mass % 0.1 0.1 0.3 0.1 2 0.1
hydrocarbon ratio carbon number: C.sub.4 vol. % 8.4 8.5 2.4 2.1
97.9 98.0 carbon number: C.sub.5 vol. % 3.3 3.3 43.6 12.4 0.2 0.1
carbon number: C.sub.6 vol. % 2.9 2.9 53.6 19.7 0.0 0.0 carbon
number: C.sub.7 vol. % 2.4 2.5 0.3 21.0 0.0 0.0 carbon number:
C.sub.8 vol. % 80.2 79.9 0.1 23.6 0.0 0.0 carbon number: C.sub.9
vol. % 0.9 0.9 0.0 17.7 0.0 0.0 carbon number: C.sub.10+ vol. % 1.9
1.9 0.0 3.5 0.0 0.0 composition saturates vol. % 99.7 99.8 99.9
100.0 100.0 99.5 olefins vol. % 0.2 0.1 0.1 0.0 0.6 0.5 aromatics
vol. % 0.1 0.1 0.0 0.0 0.0 0.0 paraffins in saturates vol. % 100.0
100.0 98.4 100.0 100.0 100.0 branched paraffins in vol. % 91.4 91.4
83.5 53.5 34.6 34.6 paraffins oxygen mass % 0.0 0.0 0.0 0.0 0.0 0.0
distillation initial boiling point .degree. C. 30.5 30.0 32.0 31.5
-- -- 10% point .degree. C. 71.0 71.0 40.5 47.5 -- -- 30% point
.degree. C. 99.0 98.5 43.5 69.5 -- -- 50% point .degree. C. 105.0
106.0 46.5 92.5 -- -- 70% point .degree. C. 110.5 111.0 51.0 113.5
-- -- 90% point .degree. C. 121.5 122.0 58.5 129.5 -- -- final
boiling point .degree. C. 177.0 180.0 70.0 150.5 -- -- heat
capacity (liquid) kJ/kg .multidot. .degree. C. 2.071 2.075 2.197
2.167 2.368 2.369 heat capacity (gas) kJ/kg .multidot. .degree. C.
1.594 1.590 1.582 1.590 1.628 1.628 heat of vaporization kJ/kg
290.8 290.2 332.8 309.5 379.5 379.6 RVP kPa 59.5 59.0 91.0 72.3
338.0 339.0 research octane number 95.4 95.4 81.8 51.5 95.0 95.0
oxidation stability min. >1440 >1440 >1440 >1440 -- --
density g/cm.sup.3 0.6951 0.6954 0.6475 0.6825 0.5778 0.5776 net
heat of combustion kJ/kg 44501 44480 44798 44576 45681 45689 MTBE
ethanol methanol DME*18 sulfur mass % 0.1 0.1 0.1 0.1 hydrocarbon
ratio carbon number: C.sub.4 vol. % -- -- -- -- carbon number:
C.sub.5 vol. % -- -- -- -- carbon number: C.sub.6 vol. % -- -- --
-- carbon number: C.sub.7 vol. % -- -- -- -- carbon number: C.sub.8
vol. % -- -- -- -- carbon number: C.sub.9 vol. % -- -- -- -- carbon
number: C.sub.10+ vol. % -- -- -- -- composition saturates vol. %
-- -- -- -- olefins vol. % -- -- -- -- aromatics vol. % -- -- -- --
paraffins in saturates vol. % -- -- -- -- branched paraffins in
vol. % -- -- -- -- paraffins oxygen mass % 18.2 34.8 49.9 34.8
distillation initial boiling point .degree. C. 55.0 78.0 64.7 -25.0
10% point .degree. C. -- -- -- -- 30% point .degree. C. -- -- -- --
50% point .degree. C. -- -- -- -- 70% point .degree. C. -- -- -- --
90% point .degree. C. -- -- -- -- final boiling point .degree. C.
-- -- -- -- heat capacity (liquid) kJ/kg .multidot. .degree. C.
2.075 2.339 2.456 2.510 heat capacity (gas) kJ/kg .multidot.
.degree. C. 1.477 1.381 1.343 1.389 heat of vaporization kJ/kg
319.7 855.6 1096.8 467.8 RVP kPa 53.0 15.9 30.0 842.2 research
octane number 118.0 130.0 110.0 -- oxidation stability min. -- --
-- density g/cm.sup.3 0.7456 0.7963 0.7961 0.6709 net heat of
combustion kJ/kg 35171 26824 19916 28840 *1: those obtained by
desulfurization of naphtha fractions obtained by distillation of
crude oil *2: light fractions obtained by further distillation of
desulfurized whole-range naphtha *3: heavy fractions obtained by
further distillation of desulfurized whold-range naphtha *4:
fractions obtained by treating desulfurized heavy naphtha with a
reforming process *5: light components obtained by further
distilling reformate *6: middle to heavy components obtained by
further distilling reformate *7: heavy components obtained by
further distilling reformate *8: remaining fractions left after
extracting aromatiic from reformate with a sulfolane process *9:
gasoline fractions obtained by treating heavy, decreased pressure
light oils and the like with a catalytic cracking process *10:
light fractions obtained by distilling catalytic cracked gasoline
*11: heavy fractions obtained by distilling catalytic cracked
gasoline *12: gasoline fractions obtained by treating butane,
butene fractions with an alkylation process *13: gasoline fractions
obtained by treating desulfurized butane, butene fractions with an
alkylation process *14: substances obtained desulfurizing gasoline
fractions obtained by treating butane, butene fractions with an
alkylation process *15: gasoline fractions obtained by treating
desulfurized light naphtha with an isomerization process *16: "Gas
to Liquid" naphtha fractions which are obtained by cracking natural
gas or the like to CO and H.sub.2 and then subjecting to synthesis,
decomposition, and isomerization *17: desulfurized LPG fractions
*18: dimethylethel
[0083] Also, the properties of the respective fuels used for
examples and comparative examples are shown in Table 5.
5 TABLE 5 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Comp. Ex. 1 Comp. Ex. 2 Mixing
ratio LPG 1.5% 1.5% 2.5% -- -- -- desulfurized LPG -- -- -- 2.0% --
-- desulfurized light naphtha 2.0% 2.0% -- 13.0% 21.0% --
desulfurized heavy naphtha -- -- -- 7.0% -- -- desulfurized
whole-range naphtha 20.8% 17.0% -- -- -- 100.0% isomerate 12.9%
14.5% 2.5% -- 29.0% -- alkylate 49.8% 56.0% 57.5% -- 20.0% --
desulfurized alkylate -- -- -- 74.0% -- -- light catalytic cracked
gasoline -- -- 13.0% -- 19.0% -- middle to heavy
distillate-reformate 7.0% 9.0% 17.5% 4.0% -- -- MTBE 6.0% -- 7.0%
-- 11.0% -- Properties Sulfur ppm by mass 2.6 2.9 3.8 0.1 2.5 0.3
ratio by carbon number carbon number: C.sub.4 vol. % 6.5 7.0 9.2
9.0 6.1 1.6 carbon number: C.sub.5 vol. % 10.5 11.1 9.1 8.0 31.1
12.5 carbon number: C.sub.6 vol. % 13.3 13.7 6.9 9.1 32.0 19.7
carbon number: C.sub.7 vol. % 8.3 8.3 8.9 5.7 2.9 20.9 carbon
number: C.sub.8 vol. % 48.4 53.1 54.5 63.4 16.3 24.3 carbon number:
C.sub.7 + C.sub.8 vol. % 56.6 61.5 63.4 69.0 19.2 45.2 carbon
number: C.sub.9 vol. % 5.4 5.0 3.0 3.0 0.2 18.5 carbon number:
C.sub.10+ vol. % 1.7 1.7 1.5 1.8 0.4 2.5 Composition saturates vol.
% 85.7 90.0 69.0 95.3 78.3 92.8 olefins vol. % 0.1 0.1 7.1 0.1 10.3
0.0 aromatics vol. % 8.1 9.8 16.9 4.6 0.5 6.6 paraffins in
saturates vol. % 96.3 97.0 99.4 97.6 96.7 85.5 branched paraffins
in 78.3 80.5 88.0 80.8 74.1 44.4 paraffins Density g/cm.sup.3
0.7044 0.7032 0.7194 0.6973 0.6722 0.7085 Distillation initial
boiling point .degree. C. 30.0 29.5 30.0 28.5 25.5 35.0 50% point
.degree. C. 94.0 97.5 99.0 98.0 54.0 91.5 90% point .degree. C.
130.0 131.5 132.0 124.5 96.5 134.5 final boiling point .degree. C.
181.0 181.5 182.0 180.0 141.5 155.5 Reid vapor pressure kPa 67 67
67 68 87 67 Research octane number 89.2 89.1 100.0 89.7 89.0 63.4
Oxidation stability min. 1440 or 1440 or 1440 or 1440 or 1440 or
1440 or more more more more more more Heat capacity (liquid) kJ/kg
.multidot. .degree. C. 2.068 2.060 2.016 2.074 2.149 2.105 Heat
capacity (gas) kJ/kg .multidot. .degree. C. 1.532 1.531 1.486 1.561
1.556 1.523 Heat of vaporization kJ/kg 309.2 308.4 313.8 302.0
328.5 317.2
[0084] These respective fuels were subjected to a fuel cell system
evaluation test and an automotive spark ignition (SI) engine
evaluation test.
[0085] Fuel Cell System Evaluation Test
[0086] (1) Steam Reforming
[0087] A fuel and water were evaporated by electric heating and led
to a reformer filled with a noble metal type catalyst and kept at a
prescribed temperature by an electric heater to generate a reformed
gas enriched with hydrogen.
[0088] The temperature of the reformer was adjusted to be the
minimum temperature (the minimum temperature at which no THC was
contained in a reformed gas) at which reforming was completely
carried out in an initial stage of the test.
[0089] Together with steam, a reformed gas was led to a carbon
monoxide conversion apparatus (a water gas shift reaction) to
convert carbon monoxide in the reformed gas to carbon dioxide and
then the produced gas was led to a solid polymer type fuel cell to
carry out power generation.
[0090] A flow chart of a steam reforming type fuel cell system used
for the evaluation was illustrated in FIG. 1.
[0091] (2) Partial Oxidation
[0092] A fuel is evaporated by electric heating and together with
air, the evaporated fuel was led to a reformer filled with a noble
metal type catalyst and kept at a 1100.degree. C. by an electric
heater to generate a reformed gas enriched with hydrogen.
[0093] Together with steam, a reformed gas was led to a carbon
monoxide conversion apparatus (a water gas shift reaction) to
convert carbon monoxide in the reformed gas to carbon dioxide and
then the produced gas was led to a solid polymer type fuel cell to
carry out power generation.
[0094] A flow chart of a partial oxidation type fuel cell system
used for the evaluation was illustrated in FIG. 2.
[0095] (3) Evaluation Method
[0096] The amounts of H.sub.2, CO, CO.sub.2 and THC in the reformed
gas generated from a reformer were measured immediately after
starting of the evaluation test. Similarly, the amounts of H.sub.2,
CO, CO.sub.2 and THC in the reformed gas generated from a carbon
monoxide conversion apparatus were measured immediately after
starting of the evaluation test.
[0097] The power generation quantity, the fuel consumption, and the
CO.sub.2 amount emitted out of a fuel cell were measured
immediately after starting of the evaluation test and 100 hours
later from the starting.
[0098] The energy (preheating quantities) necessary to heat the
respective fuels to a prescribed reforming temperature were
calculated from the heat capacities and the heat of
vaporization.
[0099] Further, these measured values, calculated values and the
heating values of respective fuels were used for calculation of the
performance deterioration ratio of a reforming catalyst (the power
generation amount after 100 hours later from the starting divided
by the power generation amount immediately after the starting), the
thermal efficiency (the power generation amount immediately after
the starting divided by the net heat of combustion of a fuel), and
the preheating energy ratio (preheating energy divided by the power
generation amount).
[0100] Assessment tests as a fuel for an automotive spark ignition
(SI) engine:
[0101] The driveability of the fuel was evaluated wherein an
automobile is driven in accordance with the driving pattern based
on the CRC method stipulated in "CRC Report No. 483". The contents
of the assessment are determined in such a manner that, based on a
demerit assessment point to be given to any one of the phenomena
described in the assessment items shown in Table 1 by referring to
the degrees of phenomena described in Table 2 and also based on a
factor prescribed for each of the assessments which are described
in Table 3, a value of "the assessment point".times."the factor" is
calculated. This calculation is performed on all of the items
stipulated therein, and all of the results are finally summarized,
thus evaluating the driveability of the fuel.
[0102] Table 6 show each of the values measured, the values
calculated, and the assessment points.
6 TABLE 6 Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2
Evaluation results 1. As a fuel for a fuel cell Electric power
generation by steam reforming method (reforming temperature =
optimum reforming temperature *1) Optimum reforming .degree. C. 675
675 675 670 675 675 temperature Electric energy kJ/fuel kg initial
performance 29510 29790 29100 29960 29495 29850 100 hours later
29350 29620 28900 29860 29340 29730 performance 100 hours later
0.54% 0.57% 0.69% 0.33% 0.53% 0.40% deterioration ratio Thermal
efficiency initial performance 68% 68% 67% 68% 68% 67% 2) CO.sub.2
generation kg/fuel kg initial performance 3.062 3.103 3.086 3.089
3.005 3.098 Energy per CO.sub.2 KJ/CO.sub.2-kg initial performance
9639 9599 9431 9698 9817 9634 Preheating energy kJ/fuel kg 1338
1336 1317 1346 1362 3) Preheating energy 4.5% 4.5% 4.5% 4.5% 4.6%
4.5% ratio 4) Electric power generation by partial oxidation
reforming method (reforming temperature 1100.degree. C.) Electric
energy kJ/fuel kg initial performance 14230 14300 13700 14540 14500
14380 100 hours later 14100 14140 13520 14440 14370 14260
performance 100 hours later 0.91% 1.12% 1.31% 0.69% 0.90% 0.83%
deterioration ratio Thermal efficiency initial performance 33% 32%
32% 33% 33% 33% 2) CO.sub.2 generation kg/fuel kg initial
performance 3.062 3.103 3.086 3.089 3.005 3.098 Energy per CO.sub.2
KJ/CO.sub.2-kg initial performance 4648 4608 4440 4707 4826 4643
Preheating energy kJ/fuel kg 1991 1991 1948 2017 2022 1992 *3
Preheating energy 14.0% 13.9% 14.2% 13.9% 13.9% 13.8% ratio *4 2.
As a fuel for an automotive spark ignition (SI) engine 6 6 0 0 196
200 CRC assessment points Note *5 *1 the minimum temperature at
which no THC is contained in a reformed gas *2 electric energy/net
heat of combustion of fuel *3 energy necessary for heating a fuel
to a reforming temperature *4 preheating energy/electric energy
INDUSTRIAL APPLICABILITY
[0103] As described above, when the dual purpose fuel which is
formed of hydrocarbon compounds having a specific composition and
specific properties and is useful for both an automotive spark
ignition (SI) engine and fuel cell system is used as a fuel for a
fuel cell, it will be found possible to obtain a high output of
electric energy which is minimal in performance degradation, and to
concurrently satisfy all of the properties required for the fuel to
be used for the fuel cell. Moreover, since this dual purpose fuel
can be stored in an existing fuel storage apparatus constructed for
feeding fuel for an automotive spark ignition (SI) engine and this
dual purpose fuel is enabled to be fed not only for an automotive
spark ignition (SI) engine but also for a fuel cell system, as
demanded, from this single fuel storage apparatus, it is no longer
necessary to additionally provide a service station with a fuel
tank which is exclusively designed for use in a fuel cell system.
Namely, this dual purpose fuel can be stored in the conventional
gasoline tank, thereby enabling the fuel to be fed not only for an
automotive spark ignition (SI) engine but also for a fuel cell
system.
* * * * *