U.S. patent application number 12/226637 was filed with the patent office on 2010-02-18 for biofuel composition and method of producing a biofuel.
This patent application is currently assigned to New Generation Biofuels, Inc.. Invention is credited to Andrea Festuccia, Ferdinando Petrucci.
Application Number | 20100037513 12/226637 |
Document ID | / |
Family ID | 38656087 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100037513 |
Kind Code |
A1 |
Petrucci; Ferdinando ; et
al. |
February 18, 2010 |
Biofuel Composition and Method of Producing a Biofuel
Abstract
An emulsified biofuel composition comprising: (A) a continuous
phase comprising about 50-95 wt % of at least one liquid oil of
vegetable or animal origin or mixtures thereof; (B) a
water-containing dispersed phase comprising about 1-50 wt % water;
(C) about 1-25 wt % of hydroxyl-containing organic compound
selected from the group consisting of mono-, di-, tri- and
polyhydric alcohols, provided that when a monohydric alcohol is
used there is also present at least one of tert-butyl alcohol, at
least one C2-C4 alkylene glycol or a mixture of both; (D) about
0.05-10 wt % of at least one emulsifier; wherein the dispersed
water-containing droplets have an average particle size of less
than about 20 microns. The biofuel is prepared from these
components by mixing under high shear conditions, preferably with
ultrasonic energy. The emulsifier(s) preferably exhibit a
hydrophilic-lipophilic balance of about 8.5 to about 18 and the
biofuel includes a cetane enhancer and mixture of an alcohol and
mono- or poly-alkylene glycol.
Inventors: |
Petrucci; Ferdinando; (Arce
(fr), IT) ; Festuccia; Andrea; (Rome, IT) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,;KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
New Generation Biofuels,
Inc.
Lake Mary
FL
PTJ Bioenergy Holding Ltd.
Nicosia
|
Family ID: |
38656087 |
Appl. No.: |
12/226637 |
Filed: |
April 10, 2007 |
PCT Filed: |
April 10, 2007 |
PCT NO: |
PCT/US2007/008955 |
371 Date: |
September 18, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60795365 |
Apr 27, 2006 |
|
|
|
Current U.S.
Class: |
44/301 |
Current CPC
Class: |
C10L 1/1985 20130101;
Y02P 30/20 20151101; C10L 1/231 20130101; C10L 1/1811 20130101;
C10L 10/12 20130101; C10L 1/328 20130101; C10L 1/191 20130101; C10L
1/1802 20130101; C10L 10/02 20130101 |
Class at
Publication: |
44/301 |
International
Class: |
C10L 1/02 20060101
C10L001/02 |
Claims
1. A biofuel composition comprising an aqueous emulsion having: (A)
a continuous phase comprising about 50 wt % to about 95 wt % of at
least one liquid oil of vegetable or animal origin or mixtures
thereof; (B) a water-containing dispersed phase comprising about 1
wt % to about 50 wt % of water; (C) about 1 wt % to about 25 wt %
of a hydroxyl-containing organic compound selected from the group
consisting of monohydric, dihydric, trihydric and polyhydric
alcohols, provided that when a monohydric alcohol is present there
is also present at least one of tert-butyl alcohol, at least one
C2-C4 alkylene glycol or a mixture of both; (D) about 0.05 wt % to
about 10 wt % of at least one emulsifier; wherein the dispersed
phase comprises water-containing droplets having an average
particle size of less than about 20 microns and wherein all amounts
are expressed based on the total weight of the composition.
2. The biofuel of claim 1 wherein the at least one emulsifier
exhibits a hydrophilic-lipophilic balance, HLB, of about 8.5 to
about 18.
3. The biofuel of claim 2 wherein the at least one emulsifier is
selected from the group consisting of polyethylene
glycol-polypropylene glycol block copolymers, sorbitan monooleate,
sorbitan monostearate, sorbitan monopalmitate, sorbitan
monolaurate, polyoxyethylene (20) sorbitan trioleate, polyethylene
(20) sorbitan monooleate, polyethylene (20) sorbitan monolaurate,
and mixtures thereof.
4. The biofuel of claim 1 further comprising an effective amount of
an additive to increase the cetane number of the biofuel
composition.
5. The biofuel of claim 4 wherein the cetane additive is selected
from the group consisting of peroxides, nitrates, nitrites,
nitrocarbamates, and mixtures thereof.
6. The biofuel of claim 5 wherein the cetane additive is selected
from the group consisting of substituted or unsubstituted, linear,
branched or mixed linear or branched, alkyl or cycloalkyl nitrates
having up to about 10 carbon atoms, and mixtures thereof.
7. The biofuel of claim 5 wherein the cetane additive is selected
from the group consisting of dialkyl peroxides of the formula
R1OOR2 wherein R1 and R2 are the same or different alkyl groups
having 1 to about 10 carbon atoms, and mixtures thereof.
8. The biofuel of claim 5 wherein the cetane additive is selected
from the group consisting of 2-ethylhexyl nitrate,
di-tertiary-butyl peroxide and mixtures thereof.
9. The biofuel of claim 1 wherein the hydroxyl-containing organic
compound includes at least one member selected from the group
consisting of C1 to C4 straight and branched chain monoalcohols, C2
to C4 mono- and poly-alkylene glycols, derivatives of C2 to C4
mono- and poly-alkylene glycols provided that the molecular weights
of such polyalkylene glycols are suitable for use in the fuel
compositions, and mixtures thereof.
10. The biofuel of claim 9 wherein the alcohol is selected from the
group consisting of ethylene glycol, diethylene glycol, triethylene
glycol, propylene glycol, dipropylene glycol, tripropylene glycol,
and mixtures thereof.
11. The biofuel of claim 1 further comprising a supplementary low
viscosity, low density combustible liquid selected from the group
consisting of hydrocarbon solvents, paint thinner, turpentine,
mineral spirits and mixtures thereof.
12. A method of preparing an emulsified fuel composition
comprising: (A) providing the following components in the amounts
based on the total weight of the composition: (1) about 50 wt % to
about 95 wt % of at least one liquid oil of vegetable or animal
origin or mixtures thereof; (2) water in an amount sufficient to
produce a water-containing dispersed phase comprising about 1 wt %
to about 50 wt % of water; (3) about 1 wt % to about 25 wt % of a
hydroxyl-containing organic compound selected from the group
consisting of monohydric, dihydric, trihydric and polyhydric
alcohols, provided that when a monohydric alcohol is present there
is also present at least one of tert-butyl alcohol, at least one
C2-C4 alkylene glycol or a mixture of both; and (4) about 0.05 wt %
to about 10 wt % of at least one emulsifier; (B) mixing components
(A)(1)-(A)(4) with one another under conditions of high shear, thus
producing a dispersed phase comprising water-containing droplets
having an average particle size of less than about 20 microns.
13. The method of claim 12 wherein said dispersed phase comprises
water-containing droplets having an average particle size of about
0.1 to about 10 microns.
14. The method of claim 13 wherein the at least one emulsifier
exhibits a hydrophilic-lipophilic balance, HLB, of about 8.5 to
about 18.
15. The method of claim 14 wherein the at least one emulsifier is
selected from the group consisting of polyethylene
glycol-polypropylene glycol block copolymers, sorbitan monooleate,
sorbitan monostearate, sorbitan monopalmitate, sorbitan
monolaurate, polyoxyethylene (20) sorbitan trioleate, polyethylene
(20) sorbitan monooleate, polyethylene (20) sorbitan monolaurate,
and mixtures thereof.
16. The method of claim 13 including further providing an effective
amount of an additive to increase the cetane number of the biofuel
composition.
17. The method of claim 14 wherein the cetane additive is selected
from the group consisting of peroxides, nitrates, nitrites,
nitrocarbamates, and mixtures thereof.
18. The method of claim 12 wherein the hydroxyl-containing organic
compound includes at least one member selected from the group
consisting of C1 to C4 straight and branched chain monoalcohols, C2
to C4 mono- and poly-alkylene glycols, derivatives of C2 to C4
mono- and poly-alkylene glycols provided that the molecular weights
of such polyalkylene glycols are suitable for use in the fuel
compositions, and mixtures thereof.
19. The method of claim 12 wherein the components are provided and
mixed substantially simultaneously.
20. The method of claim 16 wherein the water is premixed with the
components other than the vegetable oil to produce an aqueous
mixture and the aqueous mixture is thereafter mixed with the
vegetable oil.
21. The method of claim 13 using high shear generating mixing
equipment.
22. The method of claim 21 wherein high shear is generated using
mixing equipment capable of generating and introducing ultrasonic
energy into the mixture.
23. The method of claim 22 wherein the amount of emulsifier is from
about 20% to about 90% of the amount emulsifier required to obtain
the dispersed particle size in the absence of the use of ultrasonic
energy.
24. Emulsified fuel according to claim 1 wherein the average
droplet particle size is selected from the group consisting of
about 0.01 to about 15 microns; 0.1 to about 10 microns; 0.5 to
about 5 microns, and mixtures thereof.
25. Emulsified fuel according to claim 24 further comprising an
effective amount of an additive to increase the cetane number of
the biofuel composition.
26. Emulsified fuel according to claim 25 wherein the cetane
additive is selected from the group consisting of peroxides,
nitrates, nitrites, nitrocarbamates, and mixtures thereof.
27. Emulsified fuel according to claim 1 further comprising at
least one member selected from the group consisting of thermal
stabilizers, aging stabilizers, antioxidants, coloring agents,
dyes, markers, odor modifying agents, rust inhibitors, inhibitors
of gum formation, metal deactivators, upper cylinder lubricants,
friction modifiers, detergents, bacteriostatic agents, fungicides,
microbiocides and mixtures thereof.
28. The emulsified fuel according to claim 25 wherein the
emulsifier is selected from the group consisting of polyethylene
glycol-polypropylene glycol block copolymers, sorbitan monooleate,
sorbitan monostearate, sorbitan monopalmitate, sorbitan
monolaurate, polyoxyethylene (20) sorbitan trioleate, polyethylene
(20) sorbitan monooleate, polyethylene (20) sorbitan monolaurate,
and mixtures thereof and wherein the alcohol is selected from the
group consisting of ethylene glycol, diethylene glycol, triethylene
glycol, propylene glycol, dipropylene glycol, tripropylene glycol,
and mixtures thereof.
29. The emulsified fuel according to claim 28, further comprising a
supplementary low viscosity, low density combustible liquid
selected from the group consisting of hydrocarbon solvents, paint
thinner, turpentine, mineral spirits and mixtures thereof.
30. The biofuel composition of claim 1 comprising oil obtained from
the seeds or fruits of plants or mixtures thereof.
31. The method of claim 12 comprising oil obtained from the seeds
or fruit of plants or mixtures thereof.
32. The biofuel of claim 2 wherein the at least one emulsifier
comprises a mixture of at least two emulsifiers wherein at least
one of the two emulsifiers exhibits a low HLB value of about 1 to
about 6 and at least one of the two emulsifiers exhibits a high HLB
value of about 6 to about 20, provided that the low HLB value and
the high HLB value are not both equal to 6.
33. The biofuel of claim 32 wherein: (I) the sum of (a) the weight
of water and (b) the weight of hydroxyl-containing organic
compound; divided by (II) the weight of vegetable and animal fat
and oil is lower than about 0.25.
34. The method of claim 14 wherein the at least one emulsifier
comprises a mixture of at least two emulsifiers wherein at least
one of the two emulsifiers exhibits a low HLB value of about 1 to
about 6 and at least one of the two emulsifiers exhibits a high HLB
value of about 6 to about 20, provided that the low HLB value and
the high HLB value are not both equal to 6.
35. The method of claim 34 wherein: (I) the sum of (a) the weight
of water and (b) the weight of hydroxyl-containing organic
compound; divided by (II) the weight of vegetable and animal fat
and oil is equal to or less than about 0.25.
36. An emulsified fuel mixture prepared from the following
components: (A) 1500 parts vegetable or animal oil or fat; and (B)
900 parts water; and (C) 400 parts denatured ethanol 90 wt % (180
proof); (D) 30 parts of at least one component selected from the
group consisting of (1) hydrogenated castor oil; (2) cetyl alcohol;
and (3) a mixture of (1) and (2); and optionally further comprising
500 parts of a supplementary combustible liquid.
37. A method for preparing an emulsified fuel mixture comprising:
(I) mixing (A) 400 parts denatured, water-containing ethanol 90 wt
% (180 proof); and, (B) 30 parts of at least one component selected
from the group consisting of (1) hydrogenated castor oil; (2) cetyl
alcohol; and (3) a mixture of (1) and (2) to form an additive; (II)
mixing the additive with component (B) 900 parts water, to form a
mixture (II); (III) adding mixture (II) with concurrent mixing to
(D) 1500 parts vegetable or animal oil or fat to produce a
substantially emulsified mixture.
Description
CROSS REFERENCE
[0001] The present application claims the benefit of Application
Ser. No. 60/795,365, filed Apr. 27, 2006, entitled Biofuel Additive
and Method of Producing a Biofuel, the disclosure of which is
hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to fuel additives, methods of
making such additives and fuel compositions employing such
additives, wherein the fuel is substantially based on vegetable or
animal sources.
[0003] Efforts to find alternative fuels to those derived from
petroleum, such as gasoline and diesel fuel, have led to the
development of biodiesel fuel. Traditional biodiesel is produced by
transesterification of vegetable oils or fats. In such a process, a
vegetable fat or oil reacts with an esterifying agent, typically an
alcohol, for example methanol or ethanol, with or without a
catalyst and with the input of additional energy usually at
atmospheric pressure. The time of the reaction can range from 0.5
to 8 hours depending on the temperature.
[0004] The terms "oils" and "fats" are often considered synonyms,
and for the purposes of the present application can be considered
chemically interchangeable, the distinction between such products
being that they are merely distinguished on the basis of their
physical state. For example, an "oil" is typically used to describe
products that are liquid at ambient or room temperature whereas the
term "fat" is used to describe products that are typically
substantially solid at room temperature. However, even such a
differentiation is somewhat artificial in that it is subject to the
definition of room temperature. For example, the same product may
be considered a "fat" in one latitude at a given time of the year
and be considered an "oil" at another latitude or at another time
of the year. To avoid confusion with other types of oils (such as
essential oils or oils derived from petroleum), these products will
be identified to the extent possible as "vegetable or animal oils"
or "vegetable or animal fats" but unless the context clearly
indicates otherwise, a reference to fats and oils should be
understood to refer to vegetable or animal oil components useful in
the present invention, as opposed to, e.g., petroleum oils. In
other words, if an oil obtained from petroleum, such as diesel oil,
gas oil and the like, is present in the compositions of the present
invention at all, it is present as an additive or minor component,
in other words, in an amount less than 50 wt %; for example, less
than about 40, 30, 20, 10, 5 or even 3 wt %; such as from greater
than about 0 wt % to less than about 5 wt %, or 10 wt %, or 15 wt %
or 20 wt %, or 25 wt %.
[0005] A common vegetable-oil-derived fuel, typically used as a
fuel for diesel engines is referred to as "biodiesel." Biodiesel is
made utilizing the chemical reaction known as transesterification.
The process forms two principal products, fatty acid methyl esters
(FAME, the chemical name for biodiesel) and glycerin. In this
reaction a vegetable oil or fat reacts with an esterifying agent,
usually an alcohol (e.g., methanol or ethanol), with or without a
catalyst and with the input of additional energy, normally at
atmospheric pressure. The reaction time can vary from about 0.5 to
about 8 hours depending on the temperature and whether or not a
catalyst is used. A biodiesel fuel generated in this way and used
in its pure form (in other words without being "diluted" with
another fuel, whether a petroleum based fuel or ethanol) at 100% is
referred to as "B 100". If it is diluted with another fuel, e.g.,
diesel fuel or gas oil, it is typically identified by the
percentage of biodiesel present, e.g., B5, B20, B30, etc. The
principal physical and chemical properties of traditional biodiesel
are as follows: methyl ester content >96.5%; Density at
15.degree. C. ranges from about 0.86 to about 0.90 g/cc; viscosity
at 40.degree. C. between about 3.5 and about 5.0 mm.sup.2/s;
flammability point >110.degree. C.; Cetane number >51; net
heating value equal to about 33175 kJ/L (compared to typical No. 2
diesel fuel, biodiesel has about 8.65% less heating value expressed
as BTU/gal.; i.e., 118,296 versus 129,500).
[0006] Furthermore, traditional biodiesel fuel exhibits a
distillation curve that is different from traditional gas oil. This
results in a flame profile that is longer and more compact because
of the greater viscosity and density of biodiesel compared to
petroleum-based diesel fuel. Such a flame can create operational
problems if the pressure of the volumetric fuel pump is not
increased slightly, e.g., about 1-1.5 atm. For the same reason,
modified fuel nozzles having a form more suited to the
characteristics of biodiesel need to be used; for example,
60.degree. nozzles open at the center perform best.
[0007] In addition, the use of biodiesel requires further
adjustments of the relationship of primary air to secondary air
(regulation of the combustion head). However, this introduces
further complications since increasing secondary air improves cold
performance of the engine, but slightly worsens equilibrium
combustion and vice versa. Another disadvantage of traditional
biodiesel arises from the high solvent power of methyl ester. This
can cause damage to incompatible plastics, generally present as
liners and seals, and may also create problems with deposits of gas
oil inadvertently left in the storage tanks. Therefore,
substitution for, or at least the periodic maintenance of the
polymeric components, is also required (including, for example, the
intake and return tubes, the compression seals of the pump, the
bending elements, and the liners and seals). Furthermore, the
cleaning of tanks and heaters in order to remove all residues of
fossil fuels is also strongly advised.
[0008] Traditional biodiesel mixed with lubricating oil may also
create a variety of problems because of the increase in the iodine
number of the mixture; iodine number being an indicator of organic
unsaturation. If the iodine number of the oil is greater than about
115, the mixture is susceptible to polymerization, and gummy
deposits can form in the lubrication lines, reducing the flow of
the lubricant. This can result in an undesirable need to replace
the motor's lubricant oil. In addition, because the composition of
biodiesel is very different from gas oil, its behavior in terms of
exhaust emissions sometimes markedly varies from that of gas oil,
particularly NOx emissions.
[0009] When traditional biodiesel is used in an engine with fuel
injectors, deposits tend to form in the injectors, at least two to
three times more so than when gas oil is used. Such deposits are
usually carbon deposits and tend to wear away with time,
particularly in "common rail" type motors. However, deposit
problems can be avoided with traditional biodiesel fuel if the
injection pressure is increased, e.g., to about 100 bar.
[0010] Methanol used in the transesterification process results in
a minimal addition of fossil-based CO.sub.2 in the balance of
traditional biodiesel. If the source of oil used to produce the
biodiesel is derived from renewable sources (typically referred to
as biomass), then all of the CO.sub.2 produced by the combustion of
the biodiesel is renewable. However, the problem of nitrogen
oxides, currently considered among the most undesirable by-products
of combustion, is the weak point of traditional biodiesel fuel. On
average NOx emissions increase 10-13% with respect to gas oil on
account of the high oxygen content of the biofuel. Even mixes
containing less than 100 biodiesel cause an increase in NOx
emissions. For example, for B20, the increase is around a 2-3% over
gas oil. On the other hand, CO emissions for B100 are on average
about 40% less than for gas oil whereas a B20 biodiesel mixture
emits around 15% less CO. Carbon monoxide in the motor area does
not generate significant problems and can be considered a lesser
pollutant. It is rather an indicator of poor combustion since it is
the result of a lack of oxygen.
[0011] Particulate emissions from the burning of biodiesel may be
related to the chemical composition of the source used to
synthesize the biodiesel and also may be indicative of
combustion-related problems. The danger associated with such
particulates varies with their chemical composition and to the
average dimension of the particles. Additionally, the particles can
also absorb and/or adsorb a certain amount of aromatic substances
that are considered more or less carcinogenic and/or mutagenic.
SO.sub.2 emission can be a problem if the biodiesel is not entirely
devoid of sulfur. Obviously the mixture of gas oil and biodiesel
leads to an increase in emissions of SO.sub.2 that is proportionate
to the content of fossil fuel. The use of traditional biofuel in
boilers has not yet been the subject of in-depth study. For
example, the measured quantity of particulate emissions, NOx,
SO.sub.2 and CO, from the stack of a 1750 kWatt boiler fed with
biodiesel compared with those emitted from one that burns gas oil
containing 0.25 wt % sulfur show that the pollutants emitted by
biodiesel are less than those of gas oil-with the exception of NOx,
which is higher.
[0012] Finally, on the basis of raw materials costs, biodiesel is
significantly more expensive, for example, as currently calculated
based on European costs, than regular diesel fuel. Final costs "at
the pump" can be equivalent since there currently are government
incentives to encourage the use of a non-petroleum-based fuel.
[0013] Thus, further improvements in the field of non-petroleum
based fuels, especially fuels based on renewable vegetable sources
would be highly desirable, particularly where such fuels exhibit
acceptable performance characteristics.
SUMMARY OF THE INVENTION
[0014] In one embodiment an emulsified biofuel composition suitable
for use in diesel engines comprises: (A) a continuous phase
comprising about 50-95 wt % of at least one liquid oil of vegetable
or animal origin or mixtures thereof; (B) a water-containing
dispersed phase comprising about 1-50 wt % water; (C) about 1-25 wt
% of hydroxyl-containing organic compound selected from the group
consisting of mono-, di-, tri- and polyhydric alcohols, provided
that when a monohydric alcohol is used there is also present at
least one of tert-butyl alcohol, at least one C2-C4 alkylene glycol
or a mixture of both; (D) about 0.05-10 wt % of at least one
emulsifier; wherein the dispersed water-containing droplets have an
average particle size of less than about 20 microns. The biofuel is
prepared from these components by mixing under high shear
conditions, preferably with ultrasonic energy. The at least one
emulsifier preferably exhibits a hydrophilic-lipophilic balance of
about 8.5 to about 18 and the biofuel includes a cetane enhancer
and mixture of an alcohol and mono- or poly-alkylene glycol.
[0015] In one embodiment the dispersed aqueous phase in an
emulsified fuel comprising a vegetable oil continuous phase
exhibits an average droplet particle size of about 0.01 to about 15
microns and the emulsifier(s) exhibit a hydrophilic-lipophilic
balance, HLB, of about 8.5 to about 18.
[0016] In another embodiment an emulsified fuel mixture is prepared
from the following components: (A) vegetable or animal oil or fat,
including mixtures thereof; and B) water; and (C) at least one
alcohol selected from the group consisting of C1 to C4 alcohols;
and, (D) at least one surfactant or emulsifier and optionally a
supplementary low viscosity, low density combustible liquid
selected from the group consisting of hydrocarbon solvents, paint
thinner, turpentine, mineral spirits and mixtures thereof. In one
embodiment, the latter emulsified fuel mixture can be prepared
according to the following method: (I) components (C) and (D) are
mixed with one another to produce an additive and the additive is
combined with water (B) to form mixture (II). Mixture (II) is added
with concurrent mixing, at a suitable rate to the vegetable oil,
component (A), in order to produce a substantially emulsified
mixture.
DETAILED DESCRIPTION
[0017] As used herein the following terms or phrases have the
indicated meanings.
[0018] The term "emulsion" refers to a mixture or dispersion of two
immiscible substances, liquids in the present invention, in which
one substance, the dispersed phase, is dispersed in the other
substance, the continuous phase. An emulsion is stabilized, in
other words the dispersed phase remains dispersed during the
relevant time period, such as during storage and/or immediately
prior to and during use, with the assistance of one or more
substances known as emulsifiers. An emulsion can be a water-in-oil
emulsion or an oil-in-water emulsion depending on such variables as
the amount of oil (as well as type of oil) and water present, the
conditions used to prepare the emulsion, the emulsifier type and
amount, the temperature and combinations of such variables. The
particle size or droplet size of the dispersed phase can vary over
a significant range and the emulsion can remain stable, but its
properties and suitability for a specific use may vary depending on
the particle size of the dispersed phase. Particle size is
typically expressed in terms of mean or average size since the
uniformity of the dispersed phase can also vary depending on the
variables noted above. Particle size does not require that the
particles are necessarily spheres and the size of the particles can
be based on a major or average dimension of each particle, although
in a system comprising a dispersed liquid phase in a continuous
liquid phase, fluid dynamics suggest that the dispersed particles
will tend to be substantially spherical.
[0019] The term "emulsifier" refers to a compound or mixture of
compounds that has the capacity to promote formation of an emulsion
and/or substantially stabilize an emulsion, at least for the
short-term, i.e., during the time of practical or commercial
interest. An emulsifier provides stability against significant or
substantial aggregation or coalescence of the dispersed phase of an
emulsion. An emulsifier is typically considered to be a surface
active substance in that it is capable of interacting with the
dispersed and continuous phases of an emulsion at the interface
between the two. For purposes herein a "surfactant" and an
"emulsifier" are considered equivalent or interchangeable terms.
Furthermore, within the generic term surfactant are included the
various types of surfactants such as nonionic, ionic or partially
ionic, anionic, amphoteric, cationic and zwitterionic
surfactants.
[0020] The term "cetane number" refers to a measure of diesel fuel
ignition characteristics which is analogous to octane number for
gasoline and, similarly, higher values indicate better performance.
A specific test has been developed and accepted by the fuel
industry and it is defined, for example, by various standards
setting organizations including ASTM D613, IP 41, and EN ISO 5165.
The test method determines the rating of diesel fuel oil in terms
of an arbitrary scale of cetane numbers using a standard single
cylinder, four-stroke cycle, variable compression ratio, indirect
injected diesel engine. The cetane number scale covers the range
from zero to 100 but typical test results for diesel fuel and fuels
intended for use in diesel applications are typically in the range
of 30 to 65 cetane number.
[0021] The term "flash point" generally refers to how easily a
substance or composition, typically a fluid, may ignite or burn.
The measurement of flash point is defined in test methods that are
maintained by standardization bodies such as the Energy Institute
in the UK, ASTM in the USA, CEN in Europe and ISO internationally.
For example, for diesel fuel the procedure is defined in ASTM D975.
The flash point of a fuel is essentially the lowest temperature at
which vapors from a test portion combine with air to give a
flammable mixture and "flash" when an ignition source is applied.
Materials with higher flash points are less likely to ignite than
those with lower flash points. For example, a flash point of
66.degree. C. to 93.degree. C. (150.degree. F. to 200.degree. F.)
is considered to present a moderately low ignition hazard and a
flash point of 38.degree. C. to 66.degree. C. (100.degree. F. to
150.degree. F.) is considered to present a moderate to high
ignition hazard. For reference purposes diesel fuel has a flash
point of about 38.degree. C. to 54.degree. C. (100.degree.
F.-130.degree. F.) and gasoline a flash point of about -40.degree.
C. to -46.degree. C. (-40.degree. F. to -50.degree. F.). The flash
point of a fuel is one property that needs to be considered in
determining the suitability of a fuel composition for practical
use.
[0022] The term "mixing" when used generically or without a
modifier includes each of the processes described herein for
dispersing one ingredient in another.
[0023] The term "hydrocarbyl substituent" or "hydrocarbyl group" is
used in its ordinary sense, which is well known to those skilled in
the art. Specifically, it refers to a group having a carbon atom
directly attached to the remainder of the molecule and having
predominantly hydrocarbon character. Examples of hydrocarbyl groups
include: (1) hydrocarbon substituents, that is, aliphatic (e.g.,
alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl)
substituents, and aromatic-, aliphatic-, and alicyclic-substituted
aromatic substituents, as well as cyclic substituents wherein the
ring is completed through another portion of the molecule (e.g.,
two substituents together form an alicyclic radical); (2)
substituted hydrocarbon substituents, that is, substituents
containing non-hydrocarbon groups which, in the context of this
invention, do not alter the predominantly hydrocarbon substituent
(e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,
mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); (3) hetero
substituents, that is, substituents which, while having a
predominantly hydrocarbon character, in the context of this
invention, contain other than carbon in a ring or chain otherwise
composed of carbon atoms. Heteroatoms include sulfur, oxygen,
nitrogen, and encompass substituents as pyridyl, furyl, thienyl and
imidazolyl. In general, no more than two, preferably no more than
one, non-hydrocarbon substituent will be present for every ten
carbon atoms in the hydrocarbyl group; typically, there will be no
non-hydrocarbon substituents in the hydrocarbyl group.
[0024] The term "lower" when used in conjunction with terms such as
alkyl, alkenyl, and alkoxy, is intended to describe such groups
that contain a total of up to 7 carbon atoms.
[0025] Reference in the disclosures that follow to "oil" in general
refers to vegetable oils, animal derived oils and mixtures of
vegetable and animal derived oils, including recycled versions
thereof. Unless the context of the description requires otherwise,
reference to "vegetable oil" should be understood to include a
reference to animal derived oils and mixtures of both vegetable and
animal derived oils.
[0026] The terms "stability" or "stable" when used in reference to
an emulsion refer to the dispersed or hydrophilic phase remaining
substantially dispersed in the lipophilic phase (vegetable and/or
animal oil and/or fat). In other words, substantially no phase
separation occurs as indicated by visual observation after a period
following preparation of the emulsion of at least about 24 hours;
preferably at least about 48 hours, more preferably at least about
72 hours; for example, substantially no phase separation is
observable after about 4 days or more, at ambient temperatures
suitable for use of the emulsified fuel composition in its directed
application, for example, use in burners, motor vehicles and the
like. Alternatively, stability can be characterized by measuring
sediment formation according to the test method ASTM D96.
[0027] Compositions of the present invention, characterized for
purposes of the present invention as fuel compositions, and
referred to as "biofuel," are suitable for use in internal
combustion engines, preferably diesel engines of various
configurations as well as in equipment that combusts fuels to
generate heat, such as furnaces, boilers, power generating
equipment and the like, including gas or combustion turbines.
Diesel engines that may be operated with compositions of the
present invention include all compression-ignition engines for both
mobile (including locomotive and marine) and stationary power
plants. These include diesel engines of the two-stroke-per-cycle
and four-stroke-per-cycle types. The diesel engines include but are
not limited to light and heavy duty diesel engines and on and
off-highway engines, including new engines as well as in-use
engines. The diesel engines include those used in automobiles,
trucks, buses including urban buses, locomotives, stationary
generators, and the like. For example, with regard to use in
burners, the compositions are useful in different types of oil
burners for domestic and other heating purposes including sleeve
burners, natural-draft pot burners, force-draft pot burners, rotary
wall flame burners, and air-atomizing and pressure-atomizing gun
burners; with the latter type of burner being the most commonly
used burner for home heating, particularly in the United States. In
particular, such compositions are useful fuels for diesel motors
(both new and old generation) and/or boilers and single- or
multi-step burners, also referred to in the art as staged
burners.
[0028] Various mixing devices well known in the art can be employed
to facilitate formation of an emulsified composition of the instant
embodiment as well as the present invention generally including,
for example, mixer-emulsifiers, which typically utilize a high
speed rotor operating in close proximity to a stator (such as a
type made by Charles Ross & Sons Co., NY), paddle mixers
utilizing paddles having various design configurations including,
for example, reverse pitch, anchor, leaf, gate, finger,
double-motion, helix, etc., including batch and in-line equipment,
and the like. Other methods of mixing useful in this embodiment as
well as generally in the present invention are further described
hereinbelow. The processes of various embodiments of the present
invention can be carried out at a convenient temperature,
including, for example, at ambient or room temperature, such as
about 20.degree. C. to about 22.degree. C. or even as high as
25.degree. C. The time and temperature of mixing can be varied
provided that the desired emulsified composition is achieved and,
based on subsequent observation and/or testing, it is suitably
stable until it is used, as well as during use. Under conditions
wherein sediment may form following mixing of the components of the
fuel composition, it can be desirable to wait for a period of time
in order to allow for sedimentation, if any, to occur, such
material to subsequently be removed or separated from the
emulsified fuel composition. Typically, such time period is at
least about 4 minutes; preferably about 5 minutes; more preferably
about 6 minutes or more. The preferred amount of time can readily
be determined with limited and simple experiments and such time can
be adjusted, based on, for example, the type, quality and
composition of the vegetable oil employed, as well as the other
components of the mixture, including emulsifier(s).
[0029] Mixing methods in additions to those described above are
suitable for use in the present invention and in some instances are
particularly preferred. Mixtures can be prepared with traditional
mixing or blending equipment such as vats or tank equipped with
motor driven stirrers having various configurations, e.g., paddle,
helix, etc. Mixing carried out in such equipment is time consuming,
often requiring greater than 10 minutes of mixing, for example,
about 10 to about 30 minutes, alternately about 15 to about 20
minutes in order to achieve a uniform and stable emulsion. However,
such emulsions contain dispersed particles having an average
particle size, e.g., diameter or average dimension on the order of
greater than about 20 microns; for example, about 20 to about 50
microns; alternatively about 20 to about 35 microns. Emulsions
having an average particle size of about 20 microns or greater are
referred to herein as "macroemulsions." A fuel composition having
macroemulsion characteristics will typically exhibit properties
that differ from the same fuel composition having an average
particle size that is significantly smaller, in other words, a
microemulsion or one in which the particle size is less than about
20 microns, such as 19 microns or less. For example, a given
composition in macroemulsion form may exhibit a higher viscosity,
lower flash point and poorer stability in a process requiring
extended recirculation of the fuel composition as well as requiring
a greater amount of emulsifier in order to produce a satisfactory
and stable emulsion compared to the same composition in
microemulsion form.
[0030] In a preferred method, fuel mixtures of the present
invention are prepared using ultrasonic mixing equipment, which
equipment is particularly advantageous for preparing stable
emulsions having a small particle size, for example less than about
10 microns, or about 0.01 to about 5 microns on average, in other
words embodiments of a microemulsion. Preferred equipment of this
type is available commercially as "Sonolator" ultrasonic
homogenizing system, Sonic Corp., Conn. Such microemulsions can be
prepared at ambient temperature, for example about 22.degree. C.,
and at pressures of about 500 psi to about 1500 psi, although
pressures as high as 5000 psi can also be used to produce stable
microemulsions. The Sonolator system is particularly useful in that
it can be operated in alternative, useful modes, including
semi-continuous, continuous, single-feed or multiple-feed. In
particular, such a system operated in multiple-feed mode can
utilize feed tanks containing, for example, vegetable oil, water,
emulsifier and other components, such as alcohol, cetane enhancer,
alkyl glycol or alkyl glycol derivative, etc. Such a system allows
feeding of one or more of the components simultaneously,
sequentially or intermittently in order to achieve a particularly
desirable result, including but not limited to a specific emulsion
particle size, particle size distribution, mixing time, etc. As
noted above, fuel compositions prepared using ultrasonic
emulsification can be accomplished using a lower concentration of
emulsifier for the same concentration of other components,
particularly the vegetable oil(s) and water. For example, where a
composition prepared without ultrasonic mixing requires about 1.0
wt % emulsifier to obtain a satisfactory emulsion, it may only
require less than about 0.5 wt % emulsifier with the same
composition in order to obtain a satisfactory emulsion, preferably
an enhanced emulsion in that the particle size is smaller,
resulting in a microemulsion. Typically the amount of emulsifier is
about 10% less than would be required in the absence of ultrasonic
emulsification; preferably about 20% less; more preferably about
30% less; still more preferably about 40% less; for example, about
50%, 60%, 70%, 60% or even 90% less than the amount of emulsifier
required for a satisfactory emulsion without the use of ultrasonic
energy input. For example, an emulsified fuel composition requiring
1 wt % emulsifier to obtain an average emulsion particle size of
about 20 microns can be replaced with 0.2 wt % of the same
emulsifier in the same composition to obtain an emulsion having a
particle size of about 5 microns. For purposes herein, the use of a
device that introduces ultrasonic energy for mixing and
emulsification is referred to as a "high shear" method, regardless
of the physical processes that may occur on a microscopic or
molecular scale.
[0031] Emulsification using high shear such as imparted by an
ultrasonic device results in an emulsion having a mean particle or
droplet size in the range of about 0.01 microns to less than about
20 microns; such as about 0.01 microns to about 15 microns; or
about 0.1 microns to about 10 microns; about 0.1 microns to about 8
microns; about 0.2 microns to about 6 microns; about 0.5 microns to
about 5 microns; about 0.5 microns to about 4 microns; about 0.5
microns to about 3 microns; about 0.5 microns to about 3 microns;
about 0.1 microns to about 2 microns; about 0.1 microns to about 1
micron; or about 0.1 microns to about 1 micron or less, for example
about 0.8 microns. According to a preferred embodiment of the
invention, the dispersed phase or the water-containing phase of the
fuel composition comprises droplets having a mean diameter, or
major dimension, of 5 microns or less. Thus emulsification is
conducted under conditions sufficient to provide such a mean
droplet particle size.
[0032] High-shear devices that may be used include but are not
limited to the Sonic Corporation Sonolator Homogenizing System, in
which pressure can be varied over a wide range, for example about
500 to about 5,000 psi; IKA Work Dispax, and shear mixers including
multistage, for example, three stage rotor/stator combinations. The
tip speed of the rotor/stator generators may be varied by a
variable frequency drive that controls the motor. Silverson mixer
two-stage mixer, which also incorporates a rotor/stator design and
the mixer employs high-volume pumping characteristics similar to a
centrifugal pump. Inline shear mixers employing a rotor-stator
emulsification approach (Silverson Corporation); Jet Mixers,
venturi-style/cavitation shear mixers; Microfluidizer shear mixers,
high-pressure homogenization shear mixers (Microfluidics Inc.); and
any other available high-shear generating mixer capable of
producing the desired microemulsion, including high shear mixers
selected from the group consisting of Aquashear mixers (Flow
Process Technologies Inc.), pipeline static mixers, hydraulic shear
devices, rotational shear mixers, ultrasonic mixing, and
combinations thereof.
[0033] Mixing of the components is preferably conducted at ambient,
or substantially ambient, temperature conditions. It has been
observed that in some instances mixing to obtain the emulsified
fuel composition is accompanied by a slight exothermic response.
Mixing can be satisfactorily conducted at temperatures in the range
of about 5.degree. C. to about 75.degree. C.; for example about
10.degree. C. to about 65.degree. C.; or about 15.degree. C. to
about 55.degree. C.; or about 20.degree. C. to about 45.degree. C.;
such as 22.degree. C. to about 35.degree. C.
[0034] The water used in the compositions of the present invention
can be from any source. The water employed in preparing the fuel
compositions of the present invention can be deionized, purified
for example using reverse osmosis or distillation, and/or
demineralized and have a low content of dissolved minerals, for
example, salts of calcium, sodium and magnesium, and will similarly
include little, if any, chlorine and/or fluorine as well as being
substantially free of undissolved particulate matter. Preferably
the water has been substantially demineralized by methods well
known to those skilled in the art of water treatment in order to
remove dissolved mineral salts and has also been treated to remove
other additives or chemicals, including chlorine and fluorine. The
substantial absence of such materials is expected to lead to
improvements in the condition of metal surfaces in engines and
burners, particularly the inner surfaces of cylinders and nozzles.
The water may be present in the water-vegetable oil fuel emulsions
at a concentration of about 1% to about 50% by weight;
alternatively about 2% to about 50% by weight; about 3% to about
40% by weight; about 4% to about 35% by weight; and about 5% to
about 30% water.
[0035] The fuels useful in the present invention are based on
animal derived oils and fats as well as on vegetable oils and fats,
including mixtures thereof. Vegetable oils and fats are substances
that are present, in variable percentages, in the seeds or in the
fruits of various plants. In addition to those that are typically
available in nature, the present invention can also utilize
vegetable oils and fats that are obtained from genetically
engineered plants, including algae, and including those that may be
developed to yield particularly high levels of oils and fats so
that they are particularly preferred sources of such materials for
use as fuels. Since the fats and oils are to be used in the
compositions of the present invention and burned as fuel, it is not
necessary that such fats and oils be edible. At the present time,
the most common, commercially available vegetable oils, such oils
being particularly useful herein, are obtained from the seeds of
peanuts, sunflowers, soy, sesame, colza (similar in its properties
to rapeseed oil, but obtained from the seeds of Brassica
campestris, var. oleifera), rape or canola, corn and cotton and
from the fruits of palm, olive, and coconut. The fatty substance
can be obtained from treatment of the entire fruit (for example,
olive oil), the pulp (palm oil), or just the kernel (palm seed
oil). All of these vegetable based or derived oils are examples of
oils suitable for use in the present invention. Other vegetable
oils that may be useful in the present invention include crambe
oil, jatropha oil, linseed oil, tung oil, as well as other
so-called minor oil crops as described in "Minor Oil Crops," FAO
Agricultural Services Bulletin No. 94, Food and Agricultural
Organization of the United Nations, Rome, 1992, incorporated herein
by reference, such oils generally including: among the minor edible
oil crops, argan; avocado; babassu palm; balanites; borneo tallow
nut; brazil nut; caryocar spp; cashew nut; chinese vegetable
tallow; cohune palm; the cucurbitaceae family including gourd,
buffalo gourd, fluted pumpkin, and marrow; smooth loofah;
grapeseed; illipe; kusum; macadamia nuts; mango seed; noog
abyssinia; nutmeg; perilla; pili nut; rice bran; sacha inche; seje;
shea nut; and teased. Among the minor non-edible oil crops are:
allanblackia; almond; chaulmoogra; cuphea spp.; jatropa curgas;
karanja seed; neem; papaya; tonka bean; tung; and ucuuba. Vegetable
oils are obtained from their vegetable plants, seeds, etc. by
methods well known in the art, including mechanical extraction or
pressing as well as chemical or solvent extraction, and are
typically filtered to remove extraneous matter in order to deliver
a substantially clean product. However, it is within the scope of
the present invention that used vegetable oil or fat from
commercial sources can also be used, including, for example, food
frying operations.
[0036] Furthermore, oils and fats useful in the present invention
can be obtained from animal derived sources. Such animal derived or
extracted oils include animal tissue extract, piscine oil,
cod-liver and shark-liver oil, fish oil in general, including oil
from a wide variety of oil bearing fish some of which may be farmed
for that purpose including fish oil currently being promoted by the
Alaskan fish industry, tallow and mixtures thereof. For purposes
herein, tallow refers to fat obtained from parts of the bodies of
cattle, sheep, oxen, horses, chickens and other birds raised for
food purposes, and the like as well as similar fats, such as those
obtained from plants and also referred to as tallow. Large
quantities of animal derived fats and oils can be obtained as
byproducts from meat rendering facilities. Mixtures of oils and
fats obtained from vegetable and animal sources are also useful in
the present invention.
[0037] In addition to or as part of the categories of vegetable and
animal derived oils and fats are those oils and fats obtained from
recycled oil and grease usually from restaurants and food
processing plants. Such fats and oils may originally be from
vegetable or animal sources. It is to be understood that oils and
fats from these sources can still be useful even though they may
require some pretreatment in order to remove food and other
particulate matter as well as to reduce acidity from free fatty
acids or sulfur-containing compounds that may be present, using
methods well known to those skilled in the art.
[0038] Surfactants are known to enhance the stability of an
emulsion. A surfactant may be employed in accordance with the
present invention to enhance the stability of fuel-water emulsion,
particularly over time. The following tabulation provides examples
of surfactants contemplated by the invention, although useful
surfactants are not limited to those in the table. For example,
also useful are surfactants disclosed in a comprehensive listing of
surfactants that can be found in the spectral database of Bio-Rad
Laboratories (www.informatics.bio-rad.com), including infrared
spectra and, in a number of cases, chemical composition and
chemical and physical properties and sources, incorporated herein
by reference. The compounds are generally characterized as
alcohols, nitrogen-containing compounds, esters of long chain
carboxylic acids, hydrocarbons, various esters and salts of long
chain carboxylic acids, sulfated and sulfonated compounds including
alkylaryl sulfonates isothionates, lignosulfonates, sulfated and
sulfonated alcohols, amines, amides, carboxylic acids, carboxylic
acid esters, sulfated and sulfonated polyalkoxylated materials such
as esters, ethers, nitrogen compounds, aminopolycarboxylic acids
such as ethylenediaminetetraacetic acid (EDTA),
diethylenetriaminepentaacetic acid (DTPA), and nitrilotriacetic
acid (NTA), in other words EDTA, DTPA, NTA acids and salts,
phosphates, silicates and silicones. To the extent that a
particular surfactant includes atoms, groups or compounds that may
unnecessarily contribute to pollution, e.g., sulfur, its use can be
limited to the amount necessary for producing and/or maintaining a
stable emulsion or fuel composition. Particularly preferred
surfactants include cetyl alcohol, hydrogenated castor oil and
mixtures of cetyl alcohol and hydrogenated castor oil. The
following materials, referred to as surfactants herein, can be
employed in accordance with the water-fuel composition of the
present invention.
[0039] Tabulation of Useful Surfactants
[0040] (A) Nonionic Surfactants:
[0041] Esters of polyhydric alcohols; alkoxylated amides; esters of
polyoxyalkylene, polyoxypropylene and of
polyoxyethylene-polyoxypropylene glycols; ethers of polyoxyalkylene
glycols; tertiary acetylenic glycols; and polyoxyethylated alkyl
phosphates.
[0042] (B) Anionic Surfactants:
[0043] Carboxylic acids and soaps; sulfated esters, amides,
alcohols, ethers and carboxylic acids (all salts); sulfonated
petroleum, aromatic hydrocarbons, aliphatic hydrocarbons, esters,
amides, amines, ethers, carboxylic acids, phenols and lignins (all
salts); acylated polypeptides (salts); and phosphates.
[0044] The following specific compounds are also included. In the
list that follows, the abbreviation "P.O.E." refers to
polyoxyethylene (polyethylene glycol) and the abbreviation "P.O.P."
refers to polyoxypropylene.
[0045] (C) Fatty Acids:
[0046] Caprylic acid, abietic acid, pelargonic acid, coconut oil
fatty acids, capric acid, corn oil fatty acids, lauric acid,
cottonseed oil fatty acids, myristic acid, soya oil fatty acids,
palmitic acid, tallow fatty acids, stearic acid, hydrogenated fish
oil fatty acids, behenic acid, tall oil fatty acids, undecylenic
acid, dimer acids, oleic acid, trimer acids, erucic acid, castor
oil, linoleic acid, hydrogenated castor oil, ricinoleic acid,
lanolin, naphthenic acid, and lanolin fatty acids.
[0047] (D) Fatty Acid Salts:
[0048] Lithium stearate, ammonium oleate, cadmium stearate, sodium
caprate, ammonium linoleate, calcium stearate, sodium laurate,
ammonium ricinoleate calcium oleate, sodium myristate, ammonium
naphthenates, calcium linoleate, sodium palpitate, ammonium
abietate, calcium ricinoleate, sodium stearate, morpholine laurate,
calcium naphthenates, sodium undecylenate, morpholine myristate,
cobalt stearate, sodium oleate, morpholine palmitate, cobalt
naphthenates, sodium linoleate, morpholine stearate, copper
stearate, sodium ricinoleate, morpholine undecylenate, copper
oleate, sodium naphthenates, morpholine oleate, copper
naphthenates, sodium abietate, morpholine linoleate, iron stearate,
sodium polymerized carboxylates, morpholine ricinoleate, iron
naphthenate, morpholine napthenate, lead stearate, sodium salt of
tall oil, morpholine abietate, lead oleate, potassium caprate,
triethanolamine caprate, lead naphthenate, potassium laurate,
triethanolamine laurate, magnesium stearate, potassium myristate,
triethanolamine myristate, magnesium oleate, potassium palmitate,
manganese stearate, potassium stearate, triethanolamine palmitate,
manganese naphthenate, potassium undecylenate, triethanolamine
stearate, nickel oleate, potassium oleate, strontium stearate,
potassium linoleate, triethanolamine undecylenate, tin oleate,
potassium ricinoleate, zinc laurate, potassium naphthenate,
triethanolamine oleate, zinc palmitate, potassium abietate,
triethanolamine linoleate, zinc stearate, ammonium caprate,
triethanolamine ricinoleate, zinc oleate, ammonium laurate, zinc
linoleate, ammonium myristate, triethanolamine naphthenates, zinc
naphthenate, ammonium palmitate, zinc resinate, ammonium stearate,
triethanolamine abietate, ammonium undecylenate, aluminum
palmitate, aluminum stearate, aluminum oleate, barium stearate, and
barium naphthenate.
[0049] (E) Olefins:
[0050] Linear C.sub.14 alpha-olefin, and linear C.sub.16
alpha-olefin.
[0051] (F) Phosphorous Compounds and Mercaptans:
[0052] POE octyl phosphate, sodium phosphated castor oil, ammonium
phosphated castor oil, 2-ethylhexyl polyphosphate sodium salt,
capryl polyphosphate sodium salt, sodium di(2-ethylhexyl)phosphate,
lecithin (soy phosphatides), and POE
tert-dodecylmercaptoethanol.
[0053] (G) Polyethylene and Propylene Glycol Esters:
[0054] Hydroxyethyl laurate, PEG monooleate, propylene glycol
monolaurate, hydroxyethoxyethyl laurate, PEG dioleate, ethylene
glycol monoricinoleate, propylene glycol monostearate, hydroxy
ethoxyethoxy ethyl laurate, diethylene glycol monoricinoleate,
propylene glycol dilaurate, PEG monolaurate, PEG monoricinoleate,
propylene glycol distearate, PEG dilaurate, diethylene glycol
coconate, ethylene glycol monostearate, dipropylene glycol
monostearate, POE coco fatty acids ester, diethylene glycol
monostearate, propylene glycol monooleate, POE castor oil,
triethylene glycol monostearate, ethylene glycol hydroxystearate,
propylene glycol monoricinoleate, PEG monostearate, PEG trihydroxy
stearate, propylene glycol monoisostearate, ethylene glycol
distearate, POE hydrogenated castor oil, propylene glycol
monohydroxystearate, PEG distearate, POE tall oil, PEG
monoisostearate, POE abietic acid, propylene glycol dipelargonate,
PEG diisostearate, POE lanolin, hydroxyethyl oleate, acetylated
lanolin, isopropylester of lanolin fatty acids, hydroxyethoxyethyl
oleate, POE lanolin acetylated, methoxy PEG monooleate, POE
propylene glycol monostearate, and hydroxy ethoxyethoxy ethyl
oleate.
[0055] (H) Alcohols, Phenols and Polyoxyethylene Derivates:
[0056] Stearyl alcohol, oleyl alcohol, octyl phenol, nonyl phenol,
tert-octylphenoxy ethanol, p-dodecyl phenol, dinonyl phenol,
tridecyl alcohol, tetradecyl alcohol, lanolin alcohols,
cholesterol, dimethyl hexynol, dimethyl octynediol, tetramethyl
decynediol, POE tridecyl phenyl ether, POE lanolin alcohol ether,
POE cholesterol, POE n-octylphenol, POE tert-octylphenol, POE
nonylphenol, POE dinonyl phenol, POE dodecyl phenol, POE lauryl
alcohol ether, POE cetyl alcohol ether, POE stearyl alcohol ether,
POE tetramethyldecynediol, POE oleyl alcohol ether, POP EtO, POE
isohexadecyl alcohol ether
2,6,8-trimethyl-4-nonyloxypolyethyleneoxyethanol,
polyoxypropylene-polyoxyethylene block copolymer, alkyl ether of
POE/POP, and POE tridecyl alcohol ether.
[0057] (J) Glycerol Esters:
[0058] Glycerol monocaprylate, glycerol monolaurate, glycerol
mono/dicocoate, glycerol dilaurate, glycerol monostearate, glycerol
monostearate distilled, glycerol distearate, glycerol monooleate,
glycerol dioleate, glycerol trioleate, glycerol monoisostearate,
glycerol monoricinoleate, glycerol monohydroxystearate, POE
glycerol monostearate, acetylated glycerol monostearate,
succinylated glycerol monostearate, diacetylated glycerol
monostearate tartrate, modified glycerol phthalate resin,
triglycerol monostearate, triglycerol monooleate, triglycerol
monoisostearate, decaglycerol tetraoleate, decaglycerol
decastearate, pentaerythritol monolaurate, pentaerythritol
monostearate, pentaerythritol distearate, pentaerythritol
tetrastearate, pentaerythritol monooleate, pentaerythritol
dioleate, pentaerythritol trioleate, pentaerythritol
tetraricinoleate, sorbitan monolaurate, POE sorbitan monolaurate,
sorbitan monopalmitate, POE sorbitan monopalmitate, sorbitan
monostearate, POE sorbitan monostearate, sorbitan tristearate, POE
sorbitan tristearate, sorbitan monooleate, POE sorbitan monooleate,
sorbitan sesquioleate, sorbitan trioleate, POE sorbitan trioleate,
POE sorbitol hexaoleate, POE sorbitol oleate laurate, POE sorbitol
polyoleate, POE sorbitol, beeswax-ester, sucrose monolaurate,
sucrose cocoate, sucrose monomyristate, sucrose monopalmitate,
sucrose dipalmitate, sucrose monostearate, sucrose distearate,
sucrose monooleate, sucrose dioleate, lauryl lactate, cetyl
lactate, sodium lauryl lactate, sodium stearoyl lactate, sodium
isostearoyl-2-lactylate, sodium stearoyl-2-lactylate, calcium
stearoyl-2-lactylate, sodium capryl lactate, lauryl alcohol, and
cetyl alcohol.
[0059] (K) Amides and Amide Derivatives:
[0060] Stearamide, oleamide, erucamide, behenamide, lauric acid
monoethanolamide, tallow monoethanolamide, POE lauric amide,
myristic acid diethanolamide, stearic acid diethanolamide, oleic
acid diethanolamide, POE oleic amide, coco acid diethanolamide, POE
coco amide, POE hydrogenated tallow amide, lauric acid
monoisopropanolamide, and oleic acid monoisopropanolamide.
[0061] (L) Sulfates:
[0062] Sodium n-octyl sulfate, sodium 2-ethylhexyl sulfate, sodium
decyl sulfate, sodium lauryl sulfate, sodium tridecyl sulfate,
sodium sec-tetradecyl sulfate, sodium cetyl sulfate, sodium
sec-heptadecyl sulfate, sodium oleyl sulfate, sodium oleyl stearate
sulfate, sodium tridecyl ether sulfate, potassium lauryl sulfate,
magnesium lauryl sulfate, triethanolamine lauryl sulfate, ammonium
lauryl sulfate, diethanolamine lauryl sulfate, triethanolammonium
lauryl sulfate, POE octylphenol sodium salt, alkylaryl polyether
sulfate sodium salt, sulfated POE nonylphenol sodium salt, sulfated
nonylphenyl ether of tetraethyleneglycol ammonium salt, sulfated
lauryl ether of tetraethyleneglycol sodium salt, POE sodium lauryl
monoether sulfate, POE sodium lauryl ether sulfate, POE ammonium
lauryl sulfate, sulfated oleic acid sodium salt, sulfated castor
oil-fatty acids sodium salt, sulfated propyloleate sodium salt,
sulfated isopropyloleate sodium salt, sulfated butyloleate sodium
salt, sulfated glycerol monolaurate sodium salt, sulfated glycerol
trioleate sodium salt, sulfated castor oil sodium salt, sulfonated
marine oil, sulfated neatsfoot oil sodium salt, sulfated rice bean
oil sodium salt, sulfated soya bean oil sodium salt, sulfated
synthetic sperm oil, and sulfated tallow sodium salt.
[0063] (M) Miscellaneous Surfactant Compounds:
[0064] Perfluoro surfactant-anionic, perfluoro surfactant-cationic,
ethylenediamine tetraacetic acid disodium salt,
ethylenediaminetetraacetic acid tetrasodium salt, sodium
dihydroxyethyl glycinate, trisodium nitrilotriacetate, sodium
citrate, silicone defoamer-oil, silicone defoamer-water
dispersible, sodium tetraborate, sodium carbonate, sodium
phosphate-tribasic, sodium silicate, and alkyl benzene sulfonic
acid-propylene tetramer.
[0065] (N) Sulfonates:
[0066] Sodium toluene sulfonate, sodium xylene sulfonate, sodium
cumene sulfonate, sodium dodecylbenzene sulfonate, sodium
tridecylbenzene sulfonate, sodium kerylbenzene sulfonate, calcium
dodecylbenzene sulfonate, ammonium xylene sulfonate,
triethanolammonium dodecylbenzene sulfonate, alkylammonium
dodecyl-benzene sulfonate, aliphatic hydrocarbons-sulfonic acid,
sodium petroleum sulfonate, calcium petroleum sulfonate, Bryton
barium sulfonate, magnesium petroleum sulfonate, ammonium petroleum
sulfonate, isopropylamine petroleum sulfonate, ethylenediamine
petroleum sulfonate, triethanolamine petroleum sulfonate,
sulfonated napthalene sodium diisopropyl naphthalene sulfonate,
sodium dibutyl naphthalene sulfonate, sodium benzyl naphthalene
sulfonate, sodium naphthalene formaldehyde-condensate sulfonate,
sodium polymerized alkylnaphthalene sulfonate, potassium
polymerized alkylnaphthalene sulfonate, ammonium dibutylnaphthalene
sulfonate, ethanolamine dibutylnaphthalene sulfonate, sodium
sulfooleate, sodium monobutylphenylphenol monosulfonate, disodium
dibutylphenylphenol disulfonate, potassium monoethylphenylphenol
monosulfonate, ammonium monoethylphenylphenol monosulfonate,
guanidinium monoethylphenylphenol monosulfonate, sodium
decyldiphenylether disulfonate, sodium dodecyldiphenylether
disulfonate, calcium polymerized alkyl-benzene sulfonate,
sulfonated polystyrene, sulfonated aliphatic polyester,
sodium-2-sulfoethyl oleate, sodium amyl sulfooleate, sodium lauryl
sulfoacetate, sodium diisobutyl sulfosuccinate, sodium diamyl
sulfosuccinate, sodium dihexyl sulfosuccinate, sodium dioctyl
sulfosuccinate, sodium ditridecyl sulfosuccinate, sodium
alkylarylpolyether sulfonate, and sodium lignosulfonate.
[0067] (O) Amines and Amine Derivatives:
[0068] tert-C.sub.11-C.sub.14 amine, n-dodecylamine,
n-tetradecylamine, n-hexadecylamine, n-octadecylamine,
C.sub.18-C.sub.24 amine, oleylamine, cocoamine, hydrogenated tallow
amine, tallow amine, POE tert-amine, POE stearyl amine, POE oleyl
amine, C.sub.12-C.sub.14 tert-alkylamines, ethoxylated POE
cocoamine, POE tallow amine, POE soya amine, POE octadecylamine,
N-b-hydroxyethyl stearyl imidazoline, POE (3) N-tallow trimethylene
diamine, N-b-hydroxyethyl cocoimidazoline, N-b-hydroxyethyl oleyl
imidazoline, n-dodecylamine acetate, hexadecylamine acetate,
octadecylamine acetate oleylamine acetate, cocoamine acetate,
hydrogenated tallow amine acetate, tallow amine acetate, soya amine
acetate, N-stearyl-N',N'-diethylethylene-diamine acetate,
N-oleylethylenediamine formate, cocoamidopropyl dimethyl amine
oxide, lauryl dimethylamine oxide, myristyl dimethylamine oxide,
soya amine, diococoamine, dihydrogenated tallow amine, dimethyl
hexadecylamine, dimethyl octadecylamine, dimethyl cocoamine,
dimethyl soyaamine, N-coco-1,3-diaminopropane,
N-soya-1,3-diaminopropane, N-tallow-1,3-diaminopropane,
N-coco-b-aminobutyric acid, stearamidoethyl diethylamine,
sodium-N-coco-b-amino propionate, N-tallow trimethylene diamine
diacetate, disodium-N-tallow-b-imino dipropionate,
disodium-N-lauryl-b-imino dipropionate, cetyl betaine, coco
betaine, myristamidopropyl betaine, oleyl betaine, coconut amido
betaine, oleyl amido betaine, coconut oil acid ester of sodium
isethionate, cocoamido alkyldimethylamine, behenic amido alkyl
dimethylamine, isostearic amido alkyl dimethylamine, oleic amido
alkyl dimethylamine, sodium-N-methyl-N-palmitoyl taurate,
sodium-N-methyl-N-oleyl taurate, sodium-N-coconut acid N-methyl
taurate, sodium-N-methyl-N-tall oil taurate, N-lauryl sarcosine,
cocoyl sarcosine, N-oleyl sarcosine, sodium-N-lauryl sarcosinate,
sodium carboxymethylnonylhydroxy-ethy imidazolinium hydroxide,
sodium carboxymethylundecylhydroxy-ethyl imidazolinium hydroxide,
sodium carboxymethylcocohydroxy-ethyl imidazolinium hydroxide,
sodium carboxyethyloleylhydroxy-ethyl imidazolinium hydroxide,
sodium carboxymethylstearylhydroxy-ethyl imidazolinium hydroxide,
and sodium carboxymethylsodiumcarboxy-ethyl cocoether
imidazolinium.
[0069] (P) Quaternary Amine Salts:
[0070] Dodecyltrimethyl ammonium chloride, hexadecyltrimethyl
ammonium chloride, octadecyltrimethyl ammonium chloride,
cetyltrimethyl ammonium bromide, cetyldimethylethyl ammonium
bromide, coco trimethyl ammonium chloride, tallow trimethyl
ammonium chloride, soya trimethyl ammonium chloride, dicoco
dimethyl ammonium chloride, dimethyl 80% behenyl benzyl ammonium
chloride, methyl bis(2-hydroxyethyl)coco ammonium chloride,
dihydrogenated tallow dimethyl ammonium chloride,
methyldodecylbenzyl trimethyl ammonium chloride, n-alkyl dimethyl
benzyl ammonium chloride, alkyldimethyl-3,4-dicholor-benzyl
ammoniumchloride, octylphenoxyethoxyethyl dimethyl-benzyl ammonium
chloride, octylcresoxyethoxyethyl dimethyl-benzyl ammonium
chloride, cocoamidopropyl PG-dimonium chloridephosphate,
2-hydroxyethylbenzyl stearyl imidazolinium chloride,
2-hydroxyethylbenzyl coco imidazolinium chloride, ethyl
bis(polethoxyethanol)alkyl ammonium chloride, diethyl heptadecyl
imidazolinium ethylsulfate, lauryldimethylbenzyl ammonium chloride,
stearyldimethylbenzyl ammonium chloride, laurylpyridinium chloride,
1-hexadecylpyridinium chloride, cetylpyridinium bromide, lauryl
isoquinolinium bromide, and substituted oxazoline.
[0071] In one embodiment the emulsifier or surfactant comprises at
least one sorbitan ester. The sorbitan esters include sorbitan
fatty acid esters wherein the fatty acid component of the ester
comprises a carboxylic acid of about 10 to about 100 carbon atoms,
and in one embodiment about 12 to about 24 carbon atoms. Sorbitan
is a mixture of anhydrosorbitols, principally 1,4-sorbitan and
isosorbide (Formulas I and II):
##STR00001##
Sorbitan, (also known as monoanhydrosorbitol, or sorbitol
anhydride) is a generic name for anhydrides derivable from sorbitol
by removal of one molecule of water. The sorbitan fatty acid esters
of this invention are a mixture of partial esters of sorbitol and
its anhydrides with fatty acids. These sorbitan esters can be
represented by the structure below which may be any one of a
monoester, diester, triester, tetraester, or mixtures thereof
(Formula III):
##STR00002##
In formula (III), each Z independently denotes a hydrogen atom or
C(O)R--, and each R mutually independently denotes a hydrocarbyl
group of about 9 to about 99 carbon atoms, more preferably about 11
to about 23 carbon atoms. Examples of sorbitan esters include
sorbitan stearates and sorbitan oleates, such as sorbitan stearate
(i.e., monostearate), sorbitan distearate, sorbitan tristearate,
sorbitan monooleate and sorbitan sesquioleate. Sorbitan esters are
available commercially under the trademarks "Span" and "Arlacel"
from ICI. The sorbitan esters also include polyoxyalkylene sorbitan
esters wherein the alkylene group has about 2 to about 30 carbon
atoms. These polyoxyalkylene sorbitan esters can be represented by
Formula IV:
##STR00003##
wherein in Formula IV, each R independently is an alkylene group of
about 2 to about 30 carbon atoms; R' is a hydrocarbyl group of
about 9 to about 99 carbon atoms, more preferably about 11 to about
23 carbon atoms; and w, x, y and z represent the number of repeat
oxyalkylene units. For example ethoxylation of sorbitan fatty acid
esters leads to a series of more hydrophilic: surfactants, which is
the result of hydroxy groups of sorbitan reacting with ethylene
oxide. One principal commercial class of these ethoxylated sorbitan
esters are those containing about 2 to about 80 ethylene oxide
units, and in one embodiment from about 2 to about 30 ethylene
oxide units, and in one embodiment about 4, in one embodiment about
5, and in one embodiment about 20 ethylene oxide units. They are
available from Calgene Chemical under the trademark "POLYSORBATE"
and from ICI under the trademark "TWEEN". Typical examples are
polyoxyethylene (hereinafter "POE") (20) sorbitan tristearate
(Polysorbate 65; Tween 65), POE (4) sorbitan monostearate
(Polysorbate 61; Tween 61), POE (20) sorbitan trioleate
(Polysorbate 85; Tween 85), POE (5) sorbitan monooleate
(Polysorbate 81; Tween 81), and POE (80) sorbitan monooleate
(Polysorbate 80; Tween 80). As used herein the number within the
parentheses refers to the number of ethylene oxide units present in
the composition.
[0072] The following is a list of emulsifiers that may be
particularly useful:
TABLE-US-00001 Product Name* Synonym HLB
2,4,7,9-Tetramethyl-5-decyne- 4.0 4,7-diol PEG-block-PPG-block-PEG,
Mn = 1100 4.0 PEG-block-PPG-block-PEG, Mn = 2000 4.0
PEG-block-PPG-block-PEG, Mn = 2800 4.0 PEG-block-PPG-block-PEG, Mn
= 4400 4.0 Ethylenediamine tetrakis(PO-b- 4.0 EO) tetrol, Mn = 3600
Ethylenediamine tetrakis(EO-b- 4.0 PO) tetrol, Mn = 7200
Ethylenediamine tetrakis(EO-b- 4.0 PO) tetrol, Mn = 8000 Igepal
CA-210 Polyoxyethylene(2) 4.3 isooctylphenyl ether Span 80 Sorbitan
monooleate 4.3 PPG-block-PEG-block-PPG, Mn = 3300 4.5 Igepal CO-210
Polyoxyethylene(2) nonylphenyl 4.6 ether Span 60 Sorbitan
monostearate 4.7 Brij 92 Polyoxyethylene(2) oleyl ether 4.9 Brij 72
Polyoxyethylene(2) stearyl ether 4.9 Brij 52 Polyoxyethylene(2)
cetyl ether 5.3 Span 40 Sorbitan monopalmitate 6.7 Merpol A
surfactant Nonionic, ethylene oxide 6.7 condensate
2,4,7,9-Tetramethyl-5-decyne- 8.0 4,7-diol ethoxylate Triton SP-135
8.0 Span 20 Sorbitan monolaurate 8.6 PEG-block-PPG-block-PEG, Mn =
5800 9.5 PPG-block-PEG-block-PPG, Mn = 2700 9.5 Brij 30
Polyoxyethylene(4) lauryl ether 9.7 Igepal CA-520
Polyoxyethylene(5) 10.0 isooctylphenyl ether Igepal CO-520
Polyoxyethylene(5) nonylphenyl 10.0 ether Polyoxyethylene sorbitol
10.2 hexaoleate Merpol SE surfactant 10.5 Tween 85
Polyoxyethylene(20) sorbitan 11.0 trioleate 8-Methyl-1-nonanol
propoxylate- 11.0 block-ethoxylate Polyoxyethylene sorbitan 11.4
tetraoleate Triton X-114 Polyoxyethylene(8) 12.4 isooctylphenyl
ether Brij 76 Polyoxyethylene(10) stearyl 12.4 ether Brij 97
Polyoxyethylene(10) oleyl ether 12.4 Merpol OJ surfactant 12.5 Brij
56 Polyoxyethylene(10) cetyl ether 12.9 Merpol SH surfactant 12.9
2,4,7,9-Tetramethyl-5-decyne- 13.0 4,7-diol ethoxylate (5 EO/OH)
Triton SP-190 13.0 Igepal CO-630 Polyoxyethylene(9) nonylphenyl
13.0 ether Triton N-101 Polyoxyethylene branched 13.4 nonylphenyl
ether Triton X-100 Polyoxyethylene(10) 13.5 isooctylphenyl ether
Igepal CO-720 Polyoxyethylene(12) nonylphenyl 14.2 ether
Polyoxyethylene(12) tridecyl 14.5 ether Polyoxyethylene(18)
tridecyl 14.5 ether Igepal CA-720 Polyoxyethylene(12) 14.6
isooctylphenyl ether Tween 80 Polyoxyethylene(20) sorbitan 14.9
monooleate Tween 60 Polyoxyethylene(20) sorbitan 15.0 monostearate
PEG-block-PPG-block-PEG, Mn = 2900 15.0 PPG-block-PEG-block-PPG, Mn
= 2000 15.0 Brij 78 Polyoxyethylene(20) stearyl 15.3 ether Brij 98
Polyoxyethylene(20) oleyl ether 15.3 Merpol HCS 15.5 surfactant
Tween 40 Polyoxyethylene(20) sorbitan 15.6 monopalmitate Brij 58
Polyoxyethylene(20) cetyl ether 15.7 Polyoxyethylene(20) hexadecyl
15.7 ether Polyethylene-block-poly(ethylene 16.0 glycol), Mn = 2250
Tween 20 Polyoxyethylene(20) sorbitan 16.7 monolaurate Brij 35
Polyoxyethylene(23) lauryl ether 16.9 2,4,7,9-Tetramethyl-5-decyne-
17.0 4,7-diol ethoxylate (15 EO/OH) Igepal CO-890
Polyoxyethylene(40) nonylphenyl 17.8 ether Triton X-405
Polyoxyethylene(40) 17.9 isooctylphenyl ether Brij 700
Polyoxyethylene(100) stearyl 18.8 ether Igepal CO-990
Polyoxyethylene(100) nonylphenyl 19.0 ether Igepal DM-970
Polyoxyethylene(150) 19.0 dinonylphenyl ether
PEG-block-PPG-block-PEG, Mn = 1900 20.5 PEG-block-PPG-block-PEG, Mn
= 8400 24.0 Ethylenediamine tetrakis(PO-b- 24.0 EO) tetrol, Mn =
15000 PEG-block-PPG-block-PEG, average 27.0 Mn = ca. 14,600
*Abbreviations: Mn = number average molecular weight; PEG =
polyethylene glycol; PPG = polypropylene glycol; EO = ethylene
oxide; PO = propylene oxide; HLB = hydrophilic-lipophilic
balance.
[0073] Useful emulsifiers of the types listed in the above table
can be generically represented by the following classes of chemical
compounds, members of which are commercially available and are
suitable provided that they are used in accordance with the
teachings herein such that stable emulsified compositions are
produced:
[0074] (a) sorbitol esters of the general formula
##STR00004##
in which: the radicals X are identical to or different from one
another and are each OH or R.sup.1COO.sup.-, where R.sup.1 is a
linear or branched, saturated or unsaturated, aliphatic hydrocarbon
radical optionally substituted by hydroxyls and having from 7 to 22
carbon atoms, provided that at least one of said radicals X is
R.sup.1COO.sup.-,
[0075] (b) fatty acid esters of the general formula
##STR00005##
in which: R.sup.2 is a linear or branched, saturated or
unsaturated, aliphatic hydrocarbon radical optionally substituted
by hydroxyl groups and having from 7 to 22 carbon atoms, [0076]
R.sup.3 is a linear or branched C.sub.1-C.sub.20 alkylene, [0077] n
is an integer greater than or equal to 6, and [0078] R.sup.4 is H,
linear or branched C.sub.1-C.sub.10 alkyl or
##STR00006##
[0078] where R.sup.5 is as defined above for R.sup.2; and
[0079] (c) polyalkoxylated alkylphenol of the general formula
##STR00007##
in which: R.sup.6 is a linear or branched C.sub.1-C.sub.20 alkyl,
[0080] m is an integer greater than or equal to 8, and [0081]
R.sup.7 and R.sup.8 are respectively as defined above for R.sup.3
and R.sup.4 of formula (II).
[0082] Particularly useful emulsifiers include compounds exhibiting
a hydrophilic-lipophilic balance (HLB, which refers to the size and
strength of the polar (hydrophilic) and non-polar (lipophilic)
groups that comprise the emulsifier or surfactant molecule)
typically in the range of about 1 to about 40; in another
embodiment about 5 to about 20. HLB is a well-known parameter
utilized by those skilled in the art for characterizing
emulsifiers. It is defined in detail, for example, in the
references "Emulsions: Theory and Practice, P. Becher, Reinhold
Publishing Corp., ACS Monograph, ed. 1965", in the chapter "The
chemistry of emulsifying agents" (pg. 232 et seq.); and also in
Handbook of Applied Surface and Colloid Chemistry, K. Holmberg
(Ed.), "Chapter 11, Surface Chemistry in the Petroleum Industry,"
J. R. Kanicky et al., 251-267, which also describes a method for
calculating HLB values based on chemical structure; these
references incorporated herein by reference to the extent
permitted. A well established empirical procedure for determining
HLB values for a given emulsifier may be determined experimentally
by the method of W. C. Griffin, J. Soc. Cosmetic Chem., 1, 311
(1949), incorporated herein by reference to the extent permitted.
Examples of suitable compounds are included in the above table and
are also disclosed in McCutcheon's Emulsifiers and Detergents,
1998, North American Edition (pages 1-235) & International
Edition (pages 1-199), incorporated herein by reference for their
disclosure of compounds having an HLB in the range of about 1 to
about 40; in one embodiment about 1 to about 30; in one embodiment
about 1 to 20; and in another embodiment about 4 to about 18;
alternatively, greater than about 8, for example about 8.5 or about
9 to about 18. Various useful compounds include those identified in
the above table, including for example, sorbitan monolaurate,
polyoxyethylene(20) sorbitan monooleate, and polyoxyethylene(20)
sorbitan monolaurate.
[0083] It is also possible to obtain stable emulsified fuel
compositions using a combination of emulsifiers. For purposes of
explanation and not limitation, for example instead of a single
emulsifier having an HLB value of about 12 an emulsified fuel
composition can be prepared using a mixture of emulsifiers, such as
a 50/50 mixture two emulsifiers, one having an HLB value of about
16 and the other an HLB value of about 8. Similarly combinations of
three or more emulsifiers can also be used, provided that the HLB
value of the mixture exhibits the desired overall value and the
effect of the mixture is to provide a stable emulsion. For purposes
of a mixed emulsifier composition, the HLB value of the emulsifier
mixture is calculated as a linear sum weighted average based on the
weight fraction that each of the emulsifiers represents compared to
the total amount of emulsifier present:
HLB.sub.m=.SIGMA.[(HLB.sub.n)(wt.sub.n/wt.sub.tot)]
where:
[0084] .SIGMA.=Sum of the values shown in brackets
[0085] HLB.sub.m=the HLB value of one or a mixture of
emulsifiers;
[0086] n=number of emulsifiers present in the mixture, wherein any
number of emulsifiers can be used; typically n=1 to about 5; more
typically 1 to about 4; or 1 to about 3; or 1 to about 2. For
example, it is suitable to use mixtures of 2, 3 or 4 emulsifiers to
obtain a stable emulsion;
[0087] HLB.sub.n=the HLB value of a single emulsifier if n=1 or the
HLB value of each emulsifier in a mixture of emulsifiers;
[0088] wt.sub.n=the weight, for example in grams, of each
emulsifier in a mixture of emulsifiers; and
[0089] wt.sub.tot=the total weight of all emulsifiers present in a
mixture of emulsifiers.
[0090] In a preferred embodiment a mixture of two emulsifiers is
used wherein one emulsifier has an HLB value of equal to or less
than about 6, for example about 1 to about 6.0, or about 2 to about
5.9, or about 3 to about 5.5, or about 4 to about 5.9, and the
like; and the second emulsifier has an HLB value of greater than
about 6, for example about 6 to about 20; or about 6.1 to about 18,
or about 6.5 to about 16, or about 7 to about 15, and the like;
provided that both emulsifiers do not have an HLB value of 6.
Alternatively, one emulsifier comprising a bimodal distribution of
chemical species exhibiting each of the HLB properties can be
used.
[0091] The use of multiple emulsifiers in the same emulsified fuel
composition can be advantageous in compositions in which the total
concentration of hydrophilic components is low. For example,
compositions in which the water concentration is less than about 5
wt %, such as about 1 wt % to about 5 wt %, or about 1 wt % to
about 4 wt %, or 1 wt % to about 3 wt %, or 1 wt % to about 2 wt %.
Alternatively, the concentrations of various hydrophilic or
substantially hydrophilic components can be added together for
consideration of the above recited concentrations, including water,
hydroxyl-containing component(s) such as one or more alcohols or
glycols and the like. In particular, if the ratio of the total
amount of such hydrophilic components to the total amount of
lipophilic components, the latter including but not limited to the
animal and vegetable fats and oils, is equal to or less than about
0.25, for example, about 0.05 to about 0.25 or any specific value
therebetween, including, for example, about 0.06, 0.08, 0.10, 0.12,
0.14, 0.16, 0.18, 0.20, 0.22 or 0.24, it is desirable to use a
mixture of emulsifiers as described above; in other words,
emulsifier mixtures wherein at least one emulsifier has an HLB
value of equal to or less than about 6 and at least one emulsifier
has an HLB value of greater than about 6 (subject to the provisos
expressed above). For example, a composition comprising, in wt %,
80 of vegetable oil, 4 of water and 14 of ethanol (e.g., 95 wt %
ethanol containing 5 wt % water and/or denaturants) results in a
calculated ratio of 18/80=0.225. To prepare a stable emulsion using
such components it is preferable to employ a mixture of
emulsifiers, for example, a 50/50 mixture of an emulsifier having
an HLB value of, for example, about 4 and one having an HLB value
of about 15. In contrast, a stable emulsified composition can be
prepared using a single emulsifier where the lipophilic and
hydrophilic components comprise 75 wt % vegetable oil, 1 wt %
water, and 23 wt % alcohol. Alternatively, a mixture of emulsifiers
can be used even where the calculated ratio is greater than 0.25,
particularly if the value is only slightly greater, for example
about 5% to about 10% greater. Optionally, a mixture of emulsifiers
can be used if desired; particularly if it is anticipated that the
user of such a fuel composition may subsequently introduce an
additive into the composition that might have the effect of
changing the calculated ratio.
[0092] Alcohols useful in the present invention include
hydroxyl-containing organic compounds selected from the group
consisting of (A) monohydric (one OH group) alcohols characterized
as (1) aliphatic, including straight and branched chain, and
sub-characterized within this group as paraffinic (for example,
ethanol) and olefinic (for example, allyl alcohol); (2) alicyclic
(for example, cyclohexanol); (3) aromatic (for example, phenol,
benzyl alcohol); (4) heterocyclic (for example, furfuryl alcohol);
and (5) polycyclic (for example, sterols); (B) dihydric (two OH
groups), including glycols and derivatives (for example, diols);
(C) trihydric (three OH groups), including glycerol and
derivatives; and (D) polyhydric (polyols), having three or four or
more OH groups). In particular, useful alcohols include alcohols
selected from the group consisting of C1 to C4 straight and
branched chain monoalcohols, C2 to C4 mono- and polyalkylene
glycols including ethylene glycol, diethylene glycol, triethylene
glycol, propylene glycol, dipropylene glycol, tripropylene glycol,
derivatives of C2 to C4 mono- and polyalkylene glycols provided
that the molecular weights of such polyalkylene glycols are
suitable for use in the fuel compositions of the present invention,
and mixtures thereof. Fuel compositions in which a monoalcohol is
included also preferably include at least one of tert-butyl
alcohol, at least one C2-C4 alkylene glycol or a mixture of both.
Ethyl alcohol or ethanol and propylene glycol are particularly
preferred in the compositions of the present invention. Ethanol is
available commercially in the anhydrous form (also referred to as
absolute alcohol or 100% ethanol) and as various proofs or
percentages of ethanol where the additional component in the
ethanol is water, the most common being 190 proof or 95 vol %. If
ethanol is used for purposes other than as a beverage, it is
denatured by addition of substances, such as methanol, 2-propanol,
ethyl acetate, methyl isobutyl ketone, heptane or kerosene, to make
the product undesirable for human consumption, but allows for its
use for industrial purposes, including as a component in fuel or as
a fuel. As noted, ethanol other than absolute ethanol is typically
identified by use of the term "proof," where the conversion between
proof and the concentration of ethyl alcohol is that 2 proof equals
1% by volume, typically measured at 20.degree. C., although
measurements at other temperatures are also accepted, including
e.g., 15.6.degree. C. while various denaturants are available that
can render ethanol (with or without the presence of moisture or
water) unsuitable for human consumption, certain of such
denaturants may not be suitable for use in connection with fuels
because of their adverse effects on fuel stability, vehicle engines
and fuel systems and emissions. A list of denaturants used in
connection with ethyl alcohol for various purposes can be found in
The Merck Index, Thirteenth Edition, 2001, entry 3796, page 670,
incorporated herein by reference. Physical properties of ethanol
can vary depending on whether ethanol is anhydrous, mixed with
water to various concentrations, and whether it is denatured and
the type of denaturant used. Denaturants that may be unsuitable for
use in connection with fuels are known to those skilled in the art
and are often specified by various governmental agencies. For
example, the Indian government prohibits the use of methanol,
pyrroles, turpentine, ketones and tars (high molecular weight
pyrolysis products of fossil or non-fossil vegetable matter). The
standards in ASTM D4806 and ASTM D5798, incorporated herein by
reference, describe the amount and types of denaturants typically
permitted for use in fuels and also identifies others that should
not be used in view of their potentially adverse effects, as noted
above. Furthermore, ASTM D5798 also describes the standards for
fuels for use in engines that are designed to utilize ethanol as a
substitute for petroleum, i.e., that include substantially high
percentages of ethanol. Absolute ethyl alcohol is ordinarily
understood to mean ethyl alcohol containing no more than 0.5 vol. %
water, although for purposes of the present invention, such a
moisture limitation has little significance. When used in the
vegetable oil emulsion fuel composition of the present invention,
alcohol or a mixture of the alcohols identified herein as useful,
are included at a concentration of about 1 wt % to about 25 wt %
based on the total weight of the fuel composition; or about 2 wt %
to about 22 wt %; or about 3 wt % to about 20 wt %; or about 4 wt %
to about 18 wt %; or about 5 wt % to about 20 wt %; or about 1 wt %
to about 15 wt %; or about 1 wt % to about 10 wt %; or about 1 wt %
to about 5 wt %; or about 2 wt % to about 6 wt %; alternatively,
about 3 wt % to about 8 wt %.
[0093] Alternatively, the C4 alcohol butyl alcohol is also useful
in the present invention. Where butyl alcohol is used it is
preferred to use tert-butyl alcohol because it is more readily
soluble in water. However, since n-butyl alcohol and sec-butyl
alcohol are not completely soluble in water, their use can require
a further adjustment in the type and amount of emulsifier in the
fuel composition in order to obtain a stable emulsion. Tert-butyl
alcohol can be used in place of or in combination with ethanol, for
example including mixtures in which the relative amount, by weight,
of ethanol to tert-butyl alcohol is about 95/5 to 5/95; including
useful amounts therebetween such as about 85/15, 80/20, 75/25,
70/30, 65/35, 60/40, 55/45, 50/50, 45/55, 40/60, 35/65, 30/70,
25/75, 20/80, 15/85, and about 10/90.
[0094] The water-vegetable oil fuel emulsions comprise: a
continuous vegetable oil fuel phase; a discontinuous water or
aqueous phase being comprised of aqueous droplets preferably having
a mean diameter of about 10 microns or less, for example, 5
microns; and an emulsifying amount of at least one emulsifier. The
emulsions may be prepared by various steps or sequences of addition
as described herein, including for example, (1) mixing the
vegetable oil, emulsifier and other desired additives using
standard mixing techniques to form a vegetable oil-emulsifier
mixture; and (2) mixing the vegetable oil-emulsifier mixture with
water (and optionally additional additives, including for example
ethanol, propylene glycol, cetane improver, or mixtures thereof)
under emulsifying mixing conditions to form the desired
water-vegetable oil fuel emulsion.
[0095] Optionally, additives may be added to the emulsifier, the
vegetable oil, the water or combinations thereof. The additives
include but are not limited to cetane improvers, organic solvents,
other fuels such as diesel fuel, glycols, surfactants or
emulsifiers, other additives known for their use in fuel and the
like. The additives are added to the emulsifier, vegetable oil or
the water prior to and in the alternative at the emulsification
device(s) depending upon the solubility or other fluid properties
of the additive. The additives are generally in the range of about
1% to about 40% by weight, in another embodiment about 5% to about
30% by weight, and in another embodiment about 7% to about 25% by
weight of the fuel mixture.
[0096] The vegetable oil fuel emulsifier mixtures contain about 50%
to about 95% by weight, in another embodiment about 55% to about
90% by weight; and in another embodiment about 60% to about 85% by
weight vegetable oil fuel, and it further contains about 0.05% to
about 10%, in another embodiment about 0.1% to about 10%, and in
another embodiment about 1% to about 5% by weight of at least one
emulsifier.
[0097] The water, which can optionally include but is not limited
to one or more alkylene glycol, alcohol, cetane improver or
mixtures thereof. In one embodiment the water, alcohol and/or
alkylene glycol and/or the cetane improver are mixed with one
another and fed continuously to the fuel additives stream. In
another embodiment the water, alcohol and/or alkylene glycol and/or
the cetane improver or mixtures thereof flow out of separate tanks
and/or combinations thereof into or mixed prior to the
emulsification device. In one embodiment the water, alcohol and/or
alkylene glycol and/or the cetane improver mixture meets. the
vegetable oil fuel additives mixture immediately prior to or in the
emulsification device.
[0098] Alternative methods are available for preparing one
embodiment the emulsified fuel of the present invention. For
example, vegetable oil or a vegetable oil mixture and a major
proportion, or all, of the desired amount of C1-C4 alcohol, such as
ethanol, are mixed with one another to form a two phase composition
with the alcohol as the upper phase. When the water and remaining
component(s), including emulsifier(s), are added with agitation, a
stable, emulsified composition is produced. Alternatively, the
C1-C4 alcohol, or a proportion thereof, including a major
proportion, e.g., greater than 50 wt %, can be mixed with the
components other than the water, to which the vegetable oil is
added, which results in a two phase mixture with the oil as the
upper phase. If a split addition of alcohol is used, any convenient
fraction can be used as a two-phase mixture results until the water
is added. Addition of water to this mixture with agitation produces
a stable, emulsified composition. If desired, either of the
described two phase mixtures can be produced and stored until such
time as it is desired to add the water component, with the
additional component(s) if required, to form the stable, emulsified
composition. Furthermore, the two-phase mixtures can be shipped to
a desired location before addition of the water in order to reduce
the burden of shipping water in the mixture.
[0099] An optional component of the fuel mixture referred to as
supplementary combustible liquid can be "paint thinner," turpentine
or mineral spirits. Materials of this type are generally described
in U.S. Pat. No. 5,609,678, incorporated herein by reference in its
entirety. Alternatively, the use of this component in the present
invention can be characterized as a low viscosity, low density
supplementary combustible liquid additive. Such an optional
component can be useful for the purpose of modifying one or more
properties of the fuel composition, including, for example, the
cetane number, density and viscosity. Consequently, the amount and
type of such component can be selected based on its combustion
properties as measured by the cetane number of the resulting fuel
composition, by the density of the resulting composition and by its
viscosity as well as its effect on the phase distribution of the
microemulsion in view of the amount and type of surfactant used. In
each instance the amount of the liquid added can be suitably
adjusted to produce a fuel composition having the overall balance
of properties suitable for the end use of the fuel product, for
example, as a fuel for a diesel engine, a furnace, etc., or for
adjusting the properties of the fuel composition for the ambient
temperature environment in which it is intended to be used, for
example, as an automotive diesel fuel for winter or summer use.
[0100] Useful supplementary combustible liquid additives of the
paint thinner type include products identified as hydrotreated,
light steam cracked naphtha residuum (petroleum), also referred to
as naphtha, petroleum, hydrotreated heavy, and identified as CAS
64742-48-9. This product has also been described as a complex
combination of hydrocarbons obtained by treating a petroleum
fraction with hydrogen in the presence of a catalyst. It typically
comprises hydrocarbons having carbon numbers predominantly in the
range of C6 through C13 and boiling in the range of approximately
65.degree. C. to 230.degree. C. (149.degree. F. to 446.degree. F.).
Several of its characteristic physical properties include the
following: boiling point, 155-217.degree. C.; melting point,
0.degree. C.; density, 0.76-0.79 g/cm.sup.3; vapor pressure,
0.1-0.3 kPa @ 20.degree. C.; flash point, 40-62.degree. C.;
auto-ignition temperature, 255-270.degree. C.; explosive limits,
0.7-6.0 vol % in air. A suitable material is available commercially
from Italchimica Lazio S.r.l. (Monterotondo Scalo, Italy). A
particularly useful product is one that is treated such that it is
further described as "odorless," as that term is understood in the
art. This product has a viscosity of 1.23 mm.sup.2/s (ASTM D445)
and a density of 0.772 kg/DM.sup.3 (ASTM D4052). It corresponds to
the product used in the examples hereinbelow.
[0101] For purposes of the present invention it is to be understood
that a supplementary combustible liquid component useful in the
present invention can be generally understood by those skilled in
the art to include a broad range of petroleum distillate materials
as well as supplementary combustible liquids from other sources,
for example, plant or vegetable sources. Useful products generally
boil in the range of about 145.degree. C. to about 200.degree. C.
Turpentine is a supplementary combustible fluid that could be used.
Specifications for "gum spirit of turpentine" (natural, organic or
vegetable-based turpentine) have been published by several national
bodies including the American Society for Testing and Materials
(ASTM D 13-92) and the Bureau of Indian Standards (IS 533:1973).
These standards were devised largely for the quality assessment of
turpentine intended for use as a solvent, i.e., in whole form
rather than as a chemical feedstock in which the composition is of
prime importance. They generally specify parameters such as
relative density or specific gravity, refractive index,
distillation and evaporation residues. The International
organization for Standardization (ISO), which is a world-wide
federation of national standard institutes, has issued a standard,
the main requirements of which are shown in the following Table. A
draft ISO standard for "oil of turpentine, Portugal type, Pinus
pinaster (1994)" includes physical data very similar to that in the
following Table, but with the addition of a range for optical
rotation (20.degree. C.) of -28.degree. to -35.degree..
Compositional ranges are also given for a number of constituents of
the turpentine including alpha-pinene (72-85%) and beta-pinene
(12-20%).
TABLE-US-00002 TABLE Physical Property Requirements for Gum Spirit
of Turpentine (ISO Specification 412-1976) Property Value Relative
density (20/20.degree. C.) 0.862-0.872 Refractive index (20.degree.
C., D line) 1.465-1.478 Distillation (% v/v) max 1 below
150.degree. C.; min 87 below 170.degree. C. Evaporation residue (%
m/m) max 2.5 Residue after polymerization (% v/v) max 12 Acid value
max 1 Flash point (.degree. C.) Min 32
[0102] "Turpentine substitute" is a "mineral oil" based replacement
for the vegetable-based organic solvent turpentine and it is
suitable for use herein. It is a hydrotreated light distillate of
petroleum, which forms a clear transparent liquid at ambient or
room temperature. It is a complex mixture of highly refined
hydrocarbon distillates mainly in the C9-C16 range. The liquid is
highly volatile and the vapours are flammable. It is a widely
available as a less costly substitute for turpentine. It is
commonly used as an organic solvent in painting and decorating, for
thinning oil based paint and cleaning brushes. Also known as turps
substitute, mineral turpentine, or simply turps, which can cause
confusion with vegetable-based turpentine.
[0103] White spirit, also known as Stoddard solvent is also
suitable for use herein. It is a paraffin-derived clear,
transparent liquid which is a common organic solvent used in
painting and decorating. It is a mixture of saturated aliphatic and
alicyclic C7 to C12 hydrocarbons with a maximum content of 25% of
C7 to C12 alkyl aromatic hydrocarbons. White spirit typically is
used as an extraction solvent, as a cleaning solvent, as a
degreasing solvent and as a solvent in aerosols, paints, wood
preservatives, lacquers, varnishes, and asphalt products. In
western Europe about 60% of the total white spirit consumption is
used in paints, lacquers and varnishes. White spirit is the most
widely used solvent in the paint industry.
[0104] Three different types and three different grades of white
spirit are available. The type refers to whether the solvent has
been subjected to hydrodesulfurization (removal of sulfur) alone
(Type 1), solvent extraction (Type 2) or hydrogenation (Type 3).
Each type comprises three different grades: low flash grade,
regular grade, and high flash grade. The grade is determined by the
crude oil used as the starting material and the conditions of
distillation. In addition there is Type 0, which is referred to as
distillation fraction with no further treatment, comprising
predominantly saturated C9 to C12 hydrocarbons with a boiling range
of 140-200.degree. C.
[0105] The physical properties of the three types of white spirit
are shown in the following table:
TABLE-US-00003 T1: Low T2: T3: High Property flash Regular flash
Initial boiling point (IBP) 130-144 145-174 175-200 (.degree. C.)
Final boiling point (.degree. C.) IBP + 21, max. 220 Average
relative molecular 140 150 160 mass Relative density (15.degree.
C.) 0.765 0.780 0.795 Flash point (.degree. C.) 21-30 31-54 >55
Vapor pressure (kPa, 20.degree. C.) 1.4 0.6 0.1 Volatility (n-butyl
0.47 0.15 0.04 acetate = 1) Autoignition temperature 240 240 230
(.degree. C.) Explosion limits (% by 0.6-6.5 0.6-6.5 0.6-8 volume
in air) Vapor density (air = 1) 4.5-5 4.5-5 4.5-5 Refractive index
(at 20.degree. C.) 1.41-1.44 1.41-1.44 1.41-1.44 Viscosity (cps,
25.degree. C.) 0.74-1.65 0.74-1.65 0.74-1.65 Solubility (% by
weight in <0.1 <0.1 <0.1 water) Kauri-butanol value 29-33
29-33 29-33 Aniline point (.degree. C.) 60-75 60-75 60-75
Reactivity reaction with strong oxidizing agents Odor threshold
(mg/m3) -- 0.5-5 4
[0106] The various fluids identified as "mineral spirits" are
suitable for use as a supplementary combustible fluid in the
present invention. Mineral spirits is commonly used as a paint
thinner and mild solvent and it is suitable for use herein. In
Europe, it is referred to as petroleum spirit They are especially
effective in removing oils, greases, carbon and other material from
metal. Mineral spirits is derived from the light distillate
fractions during crude oil refining and comprise C6 to C11
compounds, with the majority being C9 to C11. There are many
different substances generally referred to as mineral spirits and
each generally has a different CAS number. One common type is
mineral oil spirits identified as CAS 64475-85-0. Stoddard solvent,
referred to above is a particular type, subcategory or subset of
mineral spirits, identified as CAS 8052-41-3 and contains 30-62 wt
% alkanes, 27-40 wt % cycloalkanes, 0.3-20 wt % alkylbenzenes,
0.007-0.1 wt % other benzenes, 0.2 wt % naphthalenes and 0.3 wt %
acenaphthalenes. Commercial Stoddard Solvent products are available
under the tradenames Varsol 1 and Texsolve S. Similarly, benzine is
another, subset of mineral spirits comprising C5 to C9 hydrocarbons
and boiling at about 154.degree. C. to about 204.degree. C. Mineral
spirits on the other hand comprise 20-65 wt % alkanes, 15-40 wt %
cycloalkanes and 10-30 wt % aromatics; the specific amount of each
varying depending on the particular "mineral spirit" being
considered. General properties for mineral spirits include vapor
pressure of 2.53 mmHg; API gravity of about 48 to about 51; density
of about 0.793 at 15.degree. C. and about 0.779 at 20.degree. C.;
kinematic viscosity of 1.43 cSt (or mm2/sec) at 15.degree. C. and
1.78 cSt at 0.degree. C.
[0107] Another supplementary combustible liquid that can be used is
kerosene. Kerosene is typically defined as a refined petroleum
solvent (predominantly C.sub.9-C.sub.16 hydrocarbon, which is
typically a mixture of 25% normal paraffins, 11% branched
paraffins, 30% monocycloparraffins, 12% dicycloparaffins, 1%
tricycloparrafins, 16% mononuclear aromatics and 5% dinuclear
aromatics. (NIOSH Pocket Guide, www.cdc.gov) Alternatively, a
product known as hydrotreated kerosene (CAS No. 64742-47-8) can be
used. As its name suggests, it is derived from kerosene, or
straight run kerosene, by hydrogenation in order to saturate the
double bonds present in various molecules of kerosene. Its physical
properties are not unlike kerosene. Common physical properties and
other characteristics are shown in the following table.
[0108] Physical properties and descriptive information*
TABLE-US-00004 Property Value CAS number: 8008-20-6 molecular
weight: 170 (approximately, C.sub.9 to C.sub.16 hydrocarbons)
melting point: -51.degree. C. boiling point: 175-325.degree. C.
appearance: colorless to pale straw density: about 0.8 g/mL
specific gravity 0.95 (30.degree. C.) kinematic viscosity 2.7 cSt
(20.degree. C.) odor: Odorless flash point: 65-85.degree. C.
molecular formula: C.sub.9 to C.sub.16 hydrocarbons and others
synonyms: kerosine; coal oil; fuel oil no. 1; range oil solubility:
Insoluble in water, miscible in all petroleum solvents structural
composition varies greatly and composition: includes C.sub.9 to
C.sub.16 hydrocarbons (aliphatic and aromatic) with a boiling range
of about 175 to 325.degree. C.
Sources: Budavari, S. Ed, The Merck Index, 12th edition Merck &
Co. Inc., Rahway, N.J., 1997, p 903; MSDS: Brown oil,
www.brownoil.com/msdskerosene.htm;
www.engineeringtoolbox.com/kinematic-viscosity-d.sub.--397.html
[0109] In one embodiment an additive composition of the present
invention comprises at least one alcohol and at least one
surfactant or emulsifier and, optionally, a low viscosity, low
density supplementary combustible liquid, such as paint thinner as
well as other components described herein. The various embodiments
of the fuel compositions of the present invention are generally
prepared according to the methods described herein. In one
embodiment an additive composition, the components of which are
described herein, is added gradually to water, or vice versa, in
order to prepare a mixture, preferably with mixing during the
addition, although mixing can be carried out after the components
are added to one another. Alternatively, the individual components
of the additive mixture and the water can be combined in any
convenient order provided that a uniform mixture is obtained.
Mixing is continued until a satisfactory distribution, dispersion
or emulsion of components is achieved. Typically the additive
composition is used in an amount of about 20% by weight based on
the amount of the vegetable oil that will be present in the final
mixture. The amount of additive used can be suitably varied.
Typically, the additive is used at about 2 wt % to about 30 wt %
based on the weight of the oil present; preferably about 20 wt % to
about 28 wt %; more preferably about 10 wt % to about 30 wt % for
engines and about 10 wt % to about 20 wt % for burners and heaters.
Furthermore, higher amounts of the additive can be used, for
example, about 35 wt % or about 40 wt % or up to about 45 wt %,
keeping cost in mind so that a suitable amount is used to achieve
the desired effect and at a cost consistent with economic
requirements. Alternatively, useful amounts may include specific
concentrations of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 and 30
wt % or more, as well as ranges of values based on any two of the
individual values recited; for example, 2-30%, 5-25%, etc. In this
embodiment the additive is used in an amount sufficient to obtain a
substantially complete emulsion of water and oil present in the
composition. The mixture comprising water and additive is added to
an oil or a fat of vegetable origin, for example, colza or canola
oil. The weight ratio of water to oil typically can be varied over
a range and still be useful in the present invention, for example,
from about 4:1 to about 1:4; a preferred ratio of water to oil is
about 3:1 to about 1:3; more preferably about 2:1 to about 1:2;
still more preferably about 1:1. Mixing of the water-additive
combination with the vegetable oil is continued until a
substantially complete, or suitable, emulsion of the components is
obtained.
[0110] Cetane number or CN is to diesel fuel what octane rating is
to gasoline, it is generally recognized as a measure of the fuel's
combustion quality. Cetane is an alkane molecule, specifically
C.sub.16H.sub.34, that ignites very easily under compression, so it
is assigned a cetane number of 100. All other hydrocarbons in
diesel fuel, as well as other fuels intended for use in diesel
engines, including biodiesel and the biofuel compositions of the
present invention, are indexed to cetane as an indicator of how
well they ignite under compression. The cetane number therefore
measures how quickly the fuel starts to burn (auto-ignites) under a
standardized set of diesel engine conditions. Typical
hydrocarbon-based diesel fuel contains many hydrocarbon compounds
and there can be more than one compound susceptible to ignition in
other fuels, including the fuels of the present invention. Since
each component can exhibit a different cetane number or modify the
centane number of the fuel of which it is a component, the overall
cetane number of the fuel is an indicator of the average cetane
quality of all of the components present. A fuel with a high cetane
number starts to burn shortly after it is injected into the
cylinder; it has a short ignition delay period. Conversely, a fuel
with a low cetane number resists auto-ignition and has a longer
ignition delay period. A typical diesel engine has acceptable
performance with a fuel having a CN between about 45 to about 50.
Typically, there is no performance or emission advantage when the
CN is greater than about 50; after this point, the fuel's
performance reaches a plateau. Hydrocarbon diesel fuel sold
commercially is said to be available in two CN ranges: 40-46 for
regular diesel, and 45-50 for premium. In addition to a higher CN,
premium diesel includes additives to improve the effective CN and
lubricity of the fuel as well as detergents to clean the fuel
injectors and minimize carbon deposits, water dispersants (since
water in hydrocarbon diesel fuel is considered objectionable), and
other additives depending on geographical and seasonal needs.
Cetane number can be determined using standardized tests, including
ASTM D613 and EN ISO 5165. The cetane number rating in this test
compares the diesel fuel's performance in a standard engine with
that of a mixture of cetane and alpha-methyl-naphthalene. The
cetane number is the percentage by volume of cetane in the mixture
that has the same performance as the fuel being tested. Suitable
fuels typically will have CN values of at least about 35 to about
55; preferably about 40 to about 50; more preferably about 45 to
about 50; for example at least about 45, 46, 47, 48, 49, 50, 51,
52, 53, 54 or 55. Alternatively, cetane number can be estimated by
calculating the value according to the procedures specified in ASTM
D976, using the density of the fuel and its mid-distillation
temperature, or in ASTM D4737 using a four variable equation. When
an estimated cetane number is determined in this manner, it is
sometimes referred to as cetane index to distinguish it from the
value determined according to the engine test, as in ASTM 613. It
is understood by those skilled in the art that where a cetane index
is calculated, the value is dependent on the fuel properties and is
not affected by additives that may be included to improve cetane
number. Such additives will, of course, affect the cetane number
determined by use of an engine test since the overall fuel
composition affects the value measured in that test. Cetane index
values can also be useful for characterizing a fuel composition of
the present invention. When used, a cetane number improving
additive or mixture of additives can be present in an amount
effective to improve the CN of the fuel compositions of the present
invention to the extent desired; in other words, to a level
suitable for the particular application or use to which the
emulsified vegetable fuel will be put. In one embodiment, the
concentration of the cetane improver is at a level of up to about
10% by weight; in another embodiment about 0.05 to about 10% by
weight; in a further embodiment about 0.05 to about 5% by weight;
in a still further embodiment about 0.05 to about 1% by weight;
alternatively, about 0.1 to about 1% by weight.
[0111] Various chemical compounds have been identified that have
the ability to improve the cetane number of diesel fuel. Where
necessary or desired to meet specific performance requirements in
certain applications, one embodiment of the vegetable oil-based
water-fuel emulsion compositions of the present invention can
optionally include one or more compounds having the ability to
increase cetane number. Useful cetane improvers include but are not
limited to one or more of peroxides, nitrates, nitrites,
nitrocarbamates, mixtures thereof and the like. Useful cetane
improvers include but are not limited to nitropropane,
dinitropropane, tetranitromethane, 2-nitro-2-methyl-1-butanol,
2-methyl-2-nitro-1-propanol, and the like. Also included are
nitrate esters of substituted or unsubstituted aliphatic or
cycloaliphatic alcohols which may be monohydric or polyhydric.
These compounds include substituted and unsubstituted alkyl or
cycloalkyl nitrates having up to about 10 carbon atoms, and in one
embodiment about 2 to about 10 carbon atoms. The alkyl group may be
either linear or branched, or a mixture of linear or branched alkyl
groups. Examples of such compounds include methyl nitrate, ethyl
nitrate, n-propyl nitrate, isopropyl nitrate, allyl nitrate,
n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl
nitrate, n-amyl nitrate, isoamyl nitrate, 2-amyl nitrate, 3-amyl
nitrate, tert-amyl nitrate, n-hexyl nitrate, n-heptyl nitrate,
n-octyl nitrate, 2-ethylhexyl nitrate, sec-octyl nitrate, n-nonyl
nitrate, n-decyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate,
methylcyclohexyl nitrate, and isopropylcyclohexyl nitrate. Also
useful are the nitrate esters of alkoxy-substituted aliphatic
alcohols such as 2-ethoxyethyl nitrate, 2-(2-ethoxy-ethoxy) ethyl
nitrate, 1-methoxypropyl-2-nitrate, 4-ethoxybutyl nitrate, etc., as
well as diol nitrates such as 1,6-hexamethylene dinitrate. A useful
cetane improver is 2-ethylhexyl nitrate.
[0112] Organic peroxides can also be useful as cetane improvers in
the fuel compositions herein. Generally useful compounds are
dialkyl peroxides of the formula R1OOR2 wherein R1 and R2 are the
same or different alkyl groups having 1 to about 10 carbon atoms.
Suitable peroxide cetane improver compounds should be soluble in
the fuel composition and thermally stable at typical fuel
temperatures of operating engines. Peroxides wherein R1 and R2 are
tertiary alkyl groups having about 4 or about 5 carbon atoms are
especially useful. Examples of suitable peroxides include
di-tertiary butyl peroxide, di-tertiary amyl peroxide, diethyl
peroxide, di-n-propyl peroxide, di-n-butyl peroxide, methyl ethyl
peroxide, methyl-t-butyl peroxide, ethyl-t-butyl peroxide,
propyl-t-amyl peroxide, mixtures thereof and the like. Preferred
peroxides generally exhibit one or more and preferably most of the
following characteristics: good solubility in the fuel, suitable
water partition coefficient characteristics, good thermal stability
and handling characteristics, have no impact on fuel quality or
fuel system components, and have low toxicity. A useful peroxide is
di-tertiary butyl peroxide, also sometimes referred to as tertiary
butyl peroxide.
[0113] The biofuel of the present invention typically has a density
suitable for its use as a fuel in diesel engines and in other
applications where diesel fuel would otherwise be useful, including
in furnaces, gas or combustion turbines and other combustion
equipment. Density can be measured according to the standard test
method, EN ISO 3675, at 15.degree. C. and suitable fuels have a
density of about 850 kg/m.sup.3 to about 950 kg/m.sup.3; preferably
about 860 kg/m.sup.3 to about 910 kg/m.sup.3; for example about 870
kg/m.sup.3 to about 890 kg/m.sup.3. Alternatively, in the United
States, diesel fuel density is characterized by the standard
developed by the American Petroleum Institute, referred to as API
gravity. Typical API gravity values for fuels of the present
invention useful as fuels for diesel engines range from about 25
API to about 40 API, corresponding to specific gravity values of
about 0.904 to about 0.825 (at 60.degree. F. or 15.6.degree. C.);
preferably about 26 API gravity to about 38 API gravity; more
preferably about 27 API gravity to about 37 API gravity; for
example, about 35 API gravity, corresponding to a specific gravity
of about 0.850. The accepted formula relating API gravity to
specific gravity is: API=(141.5/Sp.Gr.)-131.5 (with the
abbreviation Sp.Gr. meaning specific gravity and wherein it is
determined at 60.degree. F. or 15.6.degree. C., as noted above.
[0114] Biofuel compositions of the present invention typically have
a viscosity so that they are suitable for use as a fuel in diesel
engines and in other applications where diesel fuel would otherwise
be useful, including furnaces and other combustion equipment.
Viscosity can be measured according to the standard test methods,
EN ISO 3104 or ASTM D445 (kinematic viscosity at 40.degree. C.),
wherein potentially useful values can be about 3 mm.sup.2/s to
about 60 mm.sup.2/s; alternatively about 3.5 mm.sup.2/s to about 50
mm.sup.2/s; or for example about 3.6 mm.sup.2/s to about 40
mm.sup.2/s; about 3 mm.sup.2/s to about 40 mm.sup.2/s; about 3
mm.sup.2/s to about 30 mm.sup.2/s; about 1 mm.sup.2/s to about 25
mm.sup.2/s; about 2 mm.sup.2/s to about 12 mm.sup.2/s; about 3
mm.sup.2/s to about 10 mm.sup.2/s; about 4 mm.sup.2/s to about 8
mm.sup.2/s; about 2 mm.sup.2/s to about 6 mm.sup.2/s; and including
viscosity values that, upon testing are suitable for use in the
application or environment of a suitable biofuel composition.
[0115] Other suitable optional ingredients can be included in the
compositions of the present invention provided that they do not
substantially adversely affect performance of the composition and
its intended use. Included in the category of such other optional
ingredients would be, for example, thermal and aging stabilizers;
coloring agents, dyes and markers, particularly those permitted in
the European Union as set forth in EN 14214:2003-5.1; agents to
modify the odor of the mixture in order to prevent inadvertent
ingestion, including, for example, alkyds; etc. Alternatively, and
if necessary, agents can be added in a suitable amount, typically
at a low concentration, that are capable of modifying or masking an
unpleasant odor or smell, if any, of the exhausted gas after
combustion. Other conventional additives and blending agents for
fuel compositions of the present invention may be present. For
example, the fuels of this invention may contain conventional
quantities of such conventional additives as rust inhibitors such
as alkylated succinic acids and anhydrides, inhibitors of gum
formation, metal deactivators, upper cylinder lubricants, friction
modifiers, detergents, antioxidants, heat stabilizers,
bacteriostatic agents, microbiocides, fungicides and the like. Such
conventional additives can be present in the fuel composition at
concentrations of up to about 1 wt % based on the total weight of
the water-vegetable oil fuel emulsion; for example about 0.01 wt %
to about 1 wt %.
[0116] The practice of the present invention, including in
particular the above described additive composition, results in the
preparation of a fuel composition based on animal or. vegetable
fats or oils and water in an emulsion that is stable for an
extended time and over a wide range of temperatures, for example
about -10.degree. C. to about +50.degree. C. Furthermore, in a test
conducted at -25.degree. C., a composition of the present
invention, for example compositions as shown in Examples 1 and 2,
including paint thinner and 30 grams of cetyl alcohol, did not
exhibit any evidence of freezing, cloudiness or phase separation.
The fuel produced according to the compositions and methods of the
present invention can be used without modification to the tanks
and/or piping systems of the motors and burners in common use. Thus
another advantage of the present invention is that it permits the
return at any moment to the use of traditional fuels without
modification of the systems in which the fuel is used.
[0117] Further advantages can be realized with certain preferred
methods and compositions of the present invention, including:
[0118] (a) Product and manufacturing costs are low and competitive
with other fuels, particularly due to the presence of water in the
composition;
[0119] (b) The present compositions do not exhibit the high solvent
power of methyl esters that are present in traditional biodiesel,
which can cause problems with polymeric materials present in the
storage systems, burners and engines, including linings, packing
rings and seals;
[0120] (c) The fuel of the present invention does not leave
deposits in the storage tanks and fuel lines, thus reducing the
need for frequent maintenance;
[0121] (d) The fuel of the invention is renewable since it is based
on vegetable and animal products that can be regularly replaced.
Furthermore, not only is the energy source renewable, but the
amount of carbon dioxide emitted during combustion corresponds very
closely to the amount of carbon dioxide used by the plants in
generating the vegetable matter which is the source of the oils or
fats. This, of course, cannot occur in the case of petroleum based
fuels;
[0122] (e) Emission of nitrogen oxides, particularly undesirable
pollutants, is reduced with respect to traditional biodiesel-based
fuels, especially in view of the water and additive mixture. In a
test using a diesel engine operating at 1500 rpm, traditional
biodiesel produced 196 mg/Nm.sup.3, whereas a composition of the
present invention under the same conditions resulted in 160
mg/Nm.sup.3, more than an 18% reduction (where Nm.sup.3 refers to
"normal" cubic meters, defined as volume at temperature
T=20.0.degree. C. (68.degree. F.), and pressure P=1.01 bar (14.72
psia);
[0123] (f) Incombustible hydrocarbons produced during the
combustion of a fuel composition of the present invention are less
than those produced by traditional biodiesel-based fuels and CO
emissions and are believed typically to be about 15%-20% less. In a
test of a fuel composition similar to that shown in Example 1
(including 30 grams of cetyl alcohol, but without paint solvent) in
a diesel engine operating at 1500 rpm, CO emissions were observed
to be reduced by 37 wt % (838 versus 1248 mg/Nm.sup.3;
[0124] (g) The chemical composition and average size of particulate
matter resulting from combustion of traditional biodiesel-based
fuels and the fuels of the present invention are subject to
variability. Limited testing for smoke has been conducted using the
Bacharach Scale (values 0 to 9, with 0 indicating the lowest level)
and employing the Zambelli Emicont 50 test instrument and a 3 meter
long exhaust pipe connected to a diesel engine (the Bacharach scale
may also be referred to in test method ASTM D 2156 which measures
smoke density in flue gasses from burning petroleum distillate
heating fuels). A comparative value of 6 was observed using a fuel
composition of the present invention as described in subparagraph
(f) above. While particulate matter generated during combustion of
traditional biodiesel based fuels is thought to serve a useful
function by absorbing some of the undesirable and polluting
aromatic compounds produced during combustion of that fuel, the
fuel of the present invention is believed to produce very little of
such aromatic compounds in the first place. Moreover, it has been
found that particulate matter produced during combustion of the
fuel of the present invention is up to about 70% less than that
produced by petroleum-based fuels and are, on average, larger than
those produced by such petroleum-based fuels. Additionally, it is
generally believed that larger particles are less dangerous since
they are less likely to be permanently retained in the lungs than
smaller particles. Particulates, measured according to UNICHIM 494
(Association for Unification in the Field of the Chemical Industry,
a standards setting organization in Italy) resulted in 0.16
mg/Nm.sup.3, well below the levels observed with gasoil (0.30
mg/Nm.sup.3) and biodiesel (0.24 mg/Nm.sup.3).
[0125] (h) Emission of SO.sub.2 does not constitute a problem for
the fuels of the present invention since there is no sulfur present
in the vegetable oil or fat and the amount and type of other
components present can be controlled in order to limit, reduce or
eliminate the presence of sulfur (as well as nitrogen).
[0126] (j) It has been observed that the biofuel compositions of
the present invention exhibit anti-microbial, anti-bacterial and
anti-mold characteristics, especially compositions comprising
hydrogenated castor oil and/or cetyl alcohol as well as ethanol.
Three different tests were performed, one each against bacteria,
spores and mould/fungi, to confirm this activity of the novel,
formulated biofuel of Example 1, containing 30 grams hydrogenated
castor oil and 500 grams paint solvent and Example 2, containing 25
grams cetyl alcohol. The biofuel compositions exhibited successful
results in the following tests:
[0127] Test for activity against spores: Successful disinfection
according to the British Standard (BS EN 1276) occurs when there is
a five log reduction in cell number within 5 minutes, meaning that
the reduction of spore number must be at least of 95% in an
assigned period of time. Based on this, the biofuel composition was
tested against germs (spores) of the following strains:
Mycobacterium smegmatis and Bacillus Stearothermophilus.
[0128] Test for activity against fungi: The tests against mold and
fungi followed the guidelines of the European standard 1275 that
requires a minimum of a four log reduction in cell number within
five minutes. The strain used was Candida albicans, strain ATCC
number 10231.
[0129] Biofuel compositions made according the methods and
components previously described include those useful, for example,
in multi-jet new generation diesel engines as well as traditional
diesel engines. Such compositions can comprise for example, about
25 to about 30 wt % water, about 40 to about 60 wt % vegetable oil
and about 15 to about 30 wt % additive.
[0130] The following aspects of the invention represent possible
alternative embodiments: [0131] 1. A fuel mixture prepared from the
following components: (A) 1500 parts vegetable oil or fat; and (B)
900 parts water; and (C) 400 parts denatured ethanol 90 wt % (180
proof); and, (D) 30 parts of at least one component selected from
the group consisting of (1) hydrogenated castor oil; (2) cetyl
alcohol; and (3) a mixture of (1) and (2). [0132] 2. The fuel
mixture of aspect 1 further comprising 500 parts of odorless paint
solvent. [0133] 3. A fuel mixture prepared from the following
components: (A) 1500 parts vegetable oil or fat; and (B) 900 parts
water; and (C) 400 parts denatured ethanol 90 wt % (180 proof);
and, (D) 30 parts of at least one component selected from the group
consisting of (1) hydrogenated castor oil; (2) cetyl alcohol; and
(3) a mixture of (1) and (2) according to the following method: (I)
components (C) and (D) are mixed with one another to form an
additive; (II) the additive is mixed with component (B) to form a
mixture (II); (III) mixture (II) is added with concurrent mixing,
at a suitable rate to (A) in order to produce a substantially
emulsified mixture. [0134] 4. A fuel additive comprising a mixture
of: (A) 400 parts denatured ethanol 90 wt % (180 proof); and, (B)
30 parts of at least one component selected from the group
consisting of (1) hydrogenated castor oil; (2) cetyl alcohol; and
(3) a mixture of (1) and (2).
[0135] The following examples are provided as specific
illustrations of embodiments of the claimed invention. It should be
understood, however, that the invention is not limited to the
specific details set forth in the examples. All parts and
percentages in the examples, as well as in the specification, are
by weight unless otherwise specified. Furthermore, any range of
numbers recited in the specification or claims, such as that
representing a particular set of properties, units of measure,
conditions, physical states or percentages, is intended to
literally incorporate expressly herein by reference or otherwise,
any number falling within such range, including any subset of
numbers within any range so recited. For example, whenever a
numerical range with a lower limit, R.sub.L, and an upper limit
R.sub.U, is disclosed, any number R falling within the range is
specifically disclosed. In particular, the following numbers R
within the range are specifically disclosed:
R=R.sub.L+k(R.sub.U-R.sub.L), where k is a variable ranging from 1%
to 100% with a 1% increment, e.g., k is 1%, 2%, 3%, 4%, 5%. . . .
50%, 51%, 52%. . . . 95%, 96%, 97%, 98%, 99%, or 100%. Moreover,
any numerical range represented by any two values of R, as
calculated above is also specifically disclosed.
[0136] For purposes of the present invention, unless otherwise
defined with respect to a specific property, characteristic or
variable, the term "substantially" as applied to any criteria, such
as a property, characteristic or variable, means to meet the stated
criteria in such measure such that one skilled in the art would
understand that the benefit to be achieved, or the condition or
property value desired is met.
[0137] Throughout the entire specification, including the claims,
the word "comprise" and variations of the word, such as
"comprising" and "comprises," as well as "have," "having,"
"includes," "include" and "including," and variations thereof,
means that the named steps, elements or materials to which it
refers are essential, but other steps, elements or materials may be
added and still form a construct within the scope of the claim or
disclosure. When recited in describing the invention and in a
claim, it means that the invention and what is claimed is
considered to be what follows and potentially more. These terms,
particularly when applied to claims, are inclusive or open-ended
and do not exclude additional, unrecited elements or methods
steps.
[0138] As used throughout the specification, including the
described embodiments, the singular forms "a," an," and "the"
include plural referents unless the context clearly dictates
otherwise. Thus, for example, reference to "a surfactant" includes
a single surfactant as well a two or more different surfactants in
combination, reference to "a vegetable oil or fat" includes
mixtures of two or more vegetable oils or fats as well as a single
vegetable oil or fat, and the like.
[0139] The term "about" encompasses greater and lesser values than
those specifically recited provided that the value of the relevant
property or condition facilitates reasonably meeting the
technologic objective(s) of the present invention as described in
detail in the specification and claims. More specifically, the term
"about" when used as a modifier for, or in conjunction with, a
variable, is intended to convey that the numbers and ranges
disclosed herein are flexible and that practice of the present
invention by those skilled in the art using, for example,
concentrations, amounts, contents, carbon numbers, temperatures,
properties such as density, purity, etc., that are outside of a
stated range or different from a single value, will achieve the
desired result, namely, a biofuel additive composition or a fuel
composition or mixture comprising such an additive.
Examples
Example 1
New Generation Hi-Pressure Injection Diesel
[0140] A fuel mixture is prepared from the following components:
[0141] 1500 grams vegetable oil or fat; and [0142] 900 grams water
(e.g., tap water); and [0143] 400 grams denatured ethanol
90.degree. (180 proof); and, [0144] (a) 30 grams hydrogenated oil
of ricin (castor oil); [0145] alternatively, a mixture using (b) 30
grams cetalol (cetyl alcohol) is prepared; and (c) a further
alternative mixture using (a)+(b) together (30 grams total) is also
prepared; and optionally, [0146] 500 grams odorless paint solvent
is also included in one or more of the above described
mixtures.
[0147] The mixture is suitable for use with a new generation high
pressure injection diesel engine. Based on current raw material
costs it is estimated that the above composition costs about 204
.epsilon./1000L (about $0.94/gal at current exchange rates). It is
expected that the cost for producing the composition on a
commercial scale will be lower. For comparison purposes, the raw
material cost of commercial biodiesel fuel is about 492
.epsilon./1000L (about $2.26/gal at current exchange rates).
Example 2
Traditional Tractor-Type Low-Pressure Injection Diesel
[0148] A fuel mixture is prepared from the following components:
[0149] 1100 grams vegetable oil; and [0150] 500 grams water; and
[0151] 250 grams ethyl alcohol (180 proof); and [0152] 25 grams
hydrogenated castor oil; or cetalol (cetyl alcohol); or mixture of
castor oil and cetalol; and [0153] 25 grams paint thinner.
[0154] The mixture is suitable for use with a traditional
tractor-type low-pressure injection diesel engine. Based on current
raw material costs it is estimated that the above composition costs
about 243 .epsilon./1000L (about $1.12/gal at current exchange
rates). It is expected that the cost for producing the composition
on a commercial scale will be lower.
Example 3
Modified Traditional Tractor-Type Low-Pressure Injection Diesel
[0155] A fuel mixture is prepared from the following components:
[0156] 1100 grams vegetable oil; [0157] 900 grams water; [0158] 250
grams ethyl alcohol (180 proof); [0159] 25 grams (a) hydrogenated
castor oil; or (b) cetalol or a mixture of (a) and (b); [0160] 300
grams odorless paint thinner.
[0161] The mixture is suitable for use with a modified traditional
tractor-type low pressure injection diesel engine.
Example 4
Fuel for Use in Oil Burners
[0162] A fuel mixture is prepared from the following components:
[0163] 900 grams oil; [0164] 500 grams water; [0165] 25 grams (a)
castor oil; or (b) cetalol; or (c) a mixture of (a) and (b); [0166]
250 grams ethyl alcohol.
[0167] The mixture is suitable for use in oil burners.
Example 5
Fuel for Use in Modified Oil Burners
[0168] A fuel mixture is prepared from the following components:
[0169] 1100 grams oil; [0170] 900 grams water; [0171] 375 grams
ethyl alcohol; [0172] 30 grams (a) hydrogenated castor oil; or (b)
cetalol.
[0173] The mixture is suitable for use in modified oil burners.
Example 6
[0174] Fuel mixtures of the present invention were prepared as
follows: the water and ethanol were first mixed with one another.
The vegetable oil was then added slowly to the alcohol-water
mixture with stirring and finally the emulsifier or surfactant was
added to the mixture containing the oil. For the composition in
which a cetane improver was used, that component was added to the
mixture at the end. The mixtures were all prepared at about ambient
or room temperature, 22.degree. C. Corresponding mixtures have been
prepared using ultrasonic mixing equipment, which equipment
particularly advantageous for preparing stable emulsions having a
small particle size, for example less than about 5 microns on
average ("Sonolator" ultrasonic homogenizing system, Sonic Corp.,
Conn.). The compositions described herein are amenable to preparing
such emulsions, also referred to herein as microemulsions. The
microemulsions could also be prepared at 22.degree. C. and at
pressures of about 500 psi to about 1500 psi, although pressures as
high as 5000 psi also produced stable microemulsions. The fuel
components and amounts are shown in the following table:
TABLE-US-00005 Cetane Fuel Mixture Vegetable oil** Water Ethanol
Emulsifier.dagger-dbl. additive* Biofuel 1 1200 g 335 g 105 g HCO:
5 g 72.95 wt % 20.36 wt % 6.38 wt % 0.31 wt % Biofuel 2 1200 g 225
g 53 g HCO: 5 g 7 g 80.53 wt % 15.11 wt % 3.56 wt % 0.33 wt % 0.47
wt % Biofuel 3 900 g 350 g 250 g Tween: 15 g 59.40 wt % 23.10 wt %
16.50 wt % 1.00 wt % **Refined soybean oil .dagger-dbl.HCO =
hydrogenated castor oil, 98% pure; Tween 80 *2-ethyl hexyl
nitrate
[0175] The above mixtures were tested for various properties and
performance characteristics under different test conditions and
using various standard fuels for comparison.
[0176] Specifically, Biofuel 3 was tested in a stationary burner
and its performance compared to gas oil, biodiesel and BTZ fuel oil
and water emulsion mixture. Descriptions and properties of the
reference fuels can be found in a published report titled,
"Sperimentazione Combustibili Analisi comparativa di combustibili
per uso civile" (Fuel Experimentation. Comparative analyses of
fuels for civic use) Dec. 5, 2005, by Stazione Sperimentale par i
Combustibili (SSC) and Consorzio Ingengneria per l'Ambiente e lo
Sviluppo Sosteniblile (IPASS); and reported at http://www.ssc.it/,
incorporated herein by reference. Biofuel 3 was tested using an
experimental thermal plant consisting of a reversed flame Ravasio
Model TRM 150 boiler with a nominal thermal capacity of 175 kW and
a Elco Klockner Model EK 3.50 S-Z burner for fuel oil. Heat
generated is discharged to a heat exchanger for measurement of
performance and exhaust gasses are also analyzed for emissions. The
following conditions were used: fuel tank temperature about
16.degree. C.; burner warm-up temperature about 60.degree. C.;
atomization pressure, 28 bar; fuel feed, 23 kg/h; thermal power,
160 kW; excess oxygen in exhaust, 6%. BTZ fuel oil was blended with
water at 13 wt % and it was blended with biodiesel (standard
mixture of fatty acid methyl esters) at 20 wt %. Test results are
reported in the following table.
[0177] Test Results
TABLE-US-00006 Fuel Tests* BTZ BTZ + Water BTZ + Biodiesel Biofuel
3 PM, mg/Nm3 21.1 10.0 11.1 13.4 PM10, mg/Nm3 20.9 10.0 11.1 10.8
NOx, mg/A/m3 560.4 469.3 543.7 122 CO, mg/Nm3 10.7 37.7 10.5 138
UHC, mg/Nm3 <0.4 0.9 <0.4 17.5 Organics 2 Formaldehyde, 20 10
30 6.44 .mu.g/Nm3 Acetaldehyde, 20 60 -- 1.93 pg/Nm3
Propionaldehyde, -- -- -- 0.41 pg/Nm3 Combustion 93.4 94.4 92.8 92
Yield, % *Abbreviations and tests: PM = total particulate matter,
UNI 13284-1; PM10 = fine particulates, <10 .mu.M, EPA 201A; NOx,
nitrogen oxides, UNI 10878; CO, carbon monoxide, UNI 9969; UHC =
unburned hydrocarbons, UNI EN 12619; Organics, SSC test method;
combustion yield or energy efficiency, UNI 10389.
In other laboratory tests Biofuel 3 exhibited an excellent flow
point of -42.degree. C. (measured according to ISO 3016-94) as well
as viscosity and lower heating capacity values (ASTM D 240-02)
typical of the class of fuel oils. As shown above, Biofuel 3 also
resulted in low NOx and other emissions. It was also observed that
Biofuel 3 exhibited a regular, stable, deep yellow flame at the
burner. An increase in density of the recirculated fuel was
observed, which response can probably be mitigated by further
improvements in emulsion particle size as well as adjustments to
the composition, according to the methods described above.
[0178] Heat capacity and low temperature characteristics of Biofuel
2 and Biofuel 3 were measured using standard thermogravimetric
analysis (TGA) and the new technique of modulated differential
scanning calorimetry (MTDSC). For TGA a heating rate of 10.degree.
C./min is used until 100.degree. C., after which the sample is
heated isothermally for one hour and then the same heating rate is
resumed until 1000.degree. C., after which the sample is thoroughly
degraded. MTDSC superimposes a sinusoidal heating wave
(.+-.0.5.degree. C., 60 sec. period) on the normally linear ramp
(5.degree. C./min.); temperature interval -20.degree. C. to
+250.degree. C. in an inert nitrogen atmosphere. The heating tests
reflected the stability of the emulsifier(s) since the solvents and
water are evaporated at 100.degree. C. The laboratory test showed
that Biofuel 1 was stable until 200.degree. C. whereas Biofuel 2
was stable until about 165.degree. C. Heat capacity (J/g*.degree.
C.) was about 1.6 for Biofuel 1 and about 1.8 for Biofuel 2,
similar to that of gas oil. Furthermore, both Biofuel 1 and Biofuel
2 did not exhibit thermal effects or freezing at -20.degree. C.
[0179] Further testing was conducted at the "Centro Universitario
di Ricerca per lo Sviluppo sostenibile" near Rome, Italy
(University Center for Research and Sustainable Development,
CIRPS). Biofuel 1 and Biofuel 2 were tested and compared to
traditional diesel fuel for power performance and emissions using
two different automobile engines, Fiat Multipla 1.9 jtd (common
rail engine) and Fiat Punto 1.7 td (aspirated engine, also called
Fiat Punto TD 70 ELX). Power tests were performed using a
dynamometer, Cartec LPS 2510, with the following results:
TABLE-US-00007 Torque Test Fuel Type Vehicle Power (kW) (Nm) 1
Diesel Multipla 84.3 215 2 Biofuel 1 '' 71.7 160 3 Biofuel 2 ''
81.5 209 4 Diesel Punto 47.7 123 5 Biofuel 1 '' 42.5 117 6 Biofuel
2 '' 45.8 127
Compared to traditional diesel, in the Fiat Multipla power
decreased about 3% with Biofuel 1 and about 15% with Biofuel 2. In
the Fiat Punto, the power decreased about 4% with Biofuel 2 and
about 11% with Biofuel 1 compared to traditional diesel. However,
it has also been reported that when traditional biodiesel is
compared to traditional diesel power decreases about 11%. (Energy
Information Administration,
www.eia.doe.gov/oiaf/analysispaper/biodiesel).
[0180] Emissions tests were conducted with Biofuel 2 using the same
vehicles according to the various standards and criteria of UNICHIM
422, 467 and 494 methods; UNI 10169 regulation; and DM 25/08/00 for
sulfur and nitrogen oxide measurements. The test results are
summarized in the following table:
TABLE-US-00008 Total Smoke Dispersed Index Temp. Carbon Bacharach
Auto/Fuel .degree. C. O2 % CO ppm SOx ppm NOx ppm Mg/Nm3 Scale*
Fiat Multipla Diesel 62 20.6 147 51.1 35 160.3 6 Biofuel 2 62.5
20.6 123 <1 1 105.7 4 Fiat Punto Diesel 57 18.4 330 57 36 157 6
Biofuel 2 54.3 18.4 313 <1 33 117 4 *Lower values indicate
better performance
The results of these tests indicate very good performance for
Biofuel 2 compared to traditional diesel fuel.
Example 7
[0181] A composition of the present invention, referred to as a
biofuel composition, having components that provided a composition
particularly useful in stationary burners or furnaces; for example,
burners used for generating heat and power. The components are
shown in the following table:
TABLE-US-00009 Biofuel 7A Amount, Amount, Useful Range, Component
grams weight % weight % Vegetable Oil 900 63.649 55-70 Water 300
21.216 15-30 Ethyl Alcohol, 95% 200 14.144 5-20 Emulsifier* 14
0.990 0.1-5 Total 1414 100.000 100.000 *Polyoxyethylene(20)
sorbitan monooleate (Tween 80)
[0182] The composition represented by Biofuel 7A was evaluated in
several standard fuel tests. The tests and results are summarized
in the following table:
TABLE-US-00010 Test Method Result API Gravity@60.degree. F. ASTM
D4052 21.04 Deg. API Sulfur ASTM D4294 0.0206 Wt % Flash Point ASTM
D93A 72.degree. F. Sediment & Water ASTM D1796 0.05 Vol %
Viscosity, Kin@100.degree. F. ASTM D445 22.93 cSt Caron Residue 10%
bottom ASTM D4530 <0.05 Wt % Sulfated Ash ASTM D874 <0.001 Wt
% Hydrogen ASTM D5291 12.27 Wt % Copper Corrosion ASTM D130 1a
Rating Total Acidity ASTM D664 0.040 mg KOH/g Stability (BS&W)
ASTM D96 <0.1% Specific Gravity@60.degree. F./60.degree. F. AOCS
Cc 10a-25 0.9341 Bomb Calorimetry ASTM D240 11,900 BTU/lb
Phosphorous ASTM D1091 3.4 ppm Sulfur ASTM D129 18 ppm Cloud point
(gel point) EN ISO 6245 -28.degree. F. Potassium EPA 258.1 <0.1
ppm Sodium EPA 273.1 <0.1 ppm Calcium EPA 215.1 3.6 ppm BTU/gal*
92,600 *Calculated from density and bomb calorimetry data
[0183] Another biofuel composition particularly useful in vehicles,
for example, cars, trucks, farm equipment, etc., preferably having
diesel engines or engines suitable for burning diesel fuels or
their equivalent, was also prepared according to the following
formula:
TABLE-US-00011 Biofuel 7B Amount, Amount, Useful Component grams
weight % Range Vegetable oil 1200 80.53 75-85% Water 225 15.11
5-20% Ethyl alcohol, 95% 53 3.56 1-5% Emulsifier* 5 0.33 0.1-5
Cetane Improver** 7 0.47 0.1-1% Total 1490 100.00 100.00 *mixture:
50 wt % Polyoxyethylene(20) sorbitan monooleate (Tween 80) + 50 wt
% Sorbitan monolaurate (Span 20) **2-ethyl hexyl nitrate
Example 8
[0184] A further Biofuel composition of the present invention was
prepared as follows: the water and propylene glycol were first
mixed with one another. Small amounts of the vegetable oil were
then added slowly to the alcohol-water mixture with stirring after
each addition and finally the emulsifier or surfactant was added to
the mixture containing the oil. The mixture was prepared at about
room temperature, 22.degree. C. Alternatively the mixture was
prepared using ultrasonic mixing equipment also as described above.
However, using such equipment it was possible to add all
ingredients simultaneously and still obtain a stable emulsion, a
microemulsion, having a small particle size, for example less than
about 5 microns on average. As above, the microemulsion could also
be prepared at 22.degree. C. and at pressures of about 500 psi to
about 1500 psi, as well as pressures as high as 5000 psi. The fuel
composition of this example utilized components resulting in a
composition particularly useful in applications requiring an
elevated flashpoint compared to the compositions identified above,
including but not limited to uses such as diesel engines for
vehicles and burners. The fuel components are shown in the
following table:
TABLE-US-00012 Biofuel 8 Amount, Useful Range, Component weight %
weight % Vegetable Oil 66 55-75 Water 23.5 15-30 Propylene glycol
9.5 5-20 Emulsifier* 1 0.1-5 Total 100.000 100.000
*Polyoxyethylene(20) sorbitan monooleate (Tween 80)
[0185] The composition represented by Biofuel 8 was evaluated in
several standard fuel tests. The tests and results are summarized
in the following table:
TABLE-US-00013 Test Method Result Units API Gravity @ 60.degree. F.
ASTM D4052 15.7 Deg. API Sulfur ASTM D4294 0.0202 Wt % Flash Point
ASTM D93 A 167-205 .degree. F. Sediment & Water ASTM D 1796 1-4
Vol % Viscosity, Kin @ 100.degree. F. ASTM D445 11-52.4 cSt Carbon
Residue 10% bottom ASTM D4530 <0.05 Wt % Sulfated Ash ASTM D 874
<0.001 Wt % Hydrogen ASTM D 5291 12.23 Wt % Copper Corrosion
ASTM D130 1a Rating Total Acidity ASTM D664 0.039 mg KOH/g
[0186] Clearly, the flash point of Biofuel 8 is significantly
higher than that of Biofuel 7A. Furthermore, mixtures of up to 25
wt % Biofuel 8 with traditional diesel fuel, biodiesel fuel and
ethanol can be prepared and the two fuel mixtures can be readily
dispersed in one another and are stable, in other words they do not
separate into different phases.
Example 9
[0187] In another experiment, adding 0.5 wt % of a cetane improver,
2-ethyl hexyl nitrate, to the composition of Biofuel 8 produced a
stable biofuel composition within the scope of the invention and
exhibiting an increased cetane number.
Example 10
[0188] Additional formulations were prepared and tested in order to
evaluate stability of vegetable oil based emulsion compositions.
The formulations are shown in the table below:
TABLE-US-00014 Example 10- Component, wt % 1 2 3 Vegetable Oil 75.9
80 80 Water 18.5 4 4 Ethyl alcohol (95%) 4.5 14 14 Emulsifier(s)*
0.6 1 0.5 + 0.5 Cetane Improver** 0.5 1 1 Total 100.0 100.0 100.0
Emulsion Stability <0.1 5 Nil Wt %, (ASTM D96) *10-1 and 10-2:
Polyoxyethylene(20) sorbitan monooleate (Tween 80); 10-3: mixture
of Tween 80 and sorbitan monooleate (Span 80) **2-ethyl hexyl
nitrate
Based on the amount of sediment that could be separated, Example
10-1 in the table above is characterized as a stable emulsion fuel
whereas Example 10-2 is considered unstable. However, by utilizing
a blend of emulsifiers with an effective HLB of 9.6
((0.5.times.14.9)+(0.5.times.4.3)) it was possible to modify the
properties of the composition sufficiently so that a stable
emulsified fuel could be obtained.
[0189] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
* * * * *
References