Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE: ETHO?CYLATED SURFACTANTS FOR WATER IN OIL
Ei~fIULSIOI~S
Related A~~lication
This is a continuation in part of USSN 13/319663 filed on 12/13/02
entitled "An Emulsified Water Blended Fuels Produced By Using A Low
Energy Process And Novel Surfactant."
Field of Invention
The invention relates to a novel additive package to produce a water
in oil emulsion, in particular water blended fuels with good emulsion
stability.
Background of the Invention
Internal combustion engines, especially diesel engines, using water
fuel blends results in the combustion chamber producing lower nitrogen
oxides (NOX), hydrocarbons and particulate matter emissions. NO,~
emissions have become an important environmental issue because it
contributes to smog and air pollution. Governmental regulations and
environmental concerns have driven the need to reduce NO,~ emissions from
engines. In particular, the U.S. Clean Air Act will require about 90% to 95%
reduction of the current level of internal combustion engines emissions by
the year 2007. Similar regulations are expected in Europe and other parts of
the industrialized world.
Diesel fueled engines produce NOX due to the relatively high flame
temperatures reached during combustion. The reduction of NOX production
conventionally includes the use of catalytic converters, using "clean" fuels,
recirculation of exhaust and engine timing changes. These methods are
typically expensive or complicated to be readily commercially available.
Water is inert toward combustion, but lowers the peak combustion
temperature resulting in reduced particulates and NO,~ formation. When
water is added to the fuel it forms an emulsion and these emulsions are
generally unstable. Stable water in fuel emulsions of a small particle size
are difficult to reach and maintain.
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An emulsion fuel has to meet the specifications of diesel fuel, as well
as additional specifications which relate to an emulsion fuel. For instance
the Italian National specification (~ecreto 20 matzo 2000, published on
3pd April 2000 in Gazzetta Ufficiale, n.78) imposes a stability test
criterion,
defined by a centrifuge test (AFN~I~ prNFIUI 07-101). In the Italian
specification a sample of emulsion (defined as containing 12-15°/~
water by
weight) is subjected to centrifugation (at a relative centrifugal force of
4200
for 5 minutes) and must show (i) no free water and, (ii) a sedimented layer of
compressed water emulsion not exceeding 9% by volume. The standard
also stipulates that no free water must be formed for a further period of
4 months. The French National specification defines similar criteria for
emulsion stability.
Another important aspect of emulsion technology is the energy
required in order to make the emulsions. Various technologies are available,
for instance static mixers, rotor-stator mills and ultrasonic devices.
Whichever technology is employed an important characteristic of a good
emulsion system (i.e. the two immiscible phases, the surfactants and carrier
fluids) is that it should emulsify quickly and, without undue high expenditure
of energy, form the desired emulsion giving a good particle size distribution.
The use of emulsified fuels have been disclosed in other patents and
patent applications of Applicant, such as USPN 6,280,485, 6,383,237,
6,368,367, 6,368,366 and 6,280,485 and USSN 09/761,482 all incorporated
herein by reference and assigned to the assignee of the present application.
It would be advantageous to develop a stable water in fuel emulsion.
Further, it would be advantageous to make more stable additive surfactant
package for the use in water in oil emulsions.
The present invention has discovered the use of surfactants to make
a water in oil emulsion/fuels. Further, the present invention has discovered
that a fatty amine ethoxylate and derivatives of a PiB succinate surfactant is
advantageous to produce a water-in oil emulsion because (1 ) emulsification
occurs readily (low residence time in the mixer); (2) more stable emulsions
are formed; (3) in addition to the excellent colloidal properties the
resultant
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emulsified fuels show a markedly improved performance in use with respects
to elastomer compatibility and corrosion; and (4) significant improvement in
the overall stability and ease of handling of the additive surfactant package.
The term "N~,~" is used herein to refer to any of the nitrogen oxides,
N~, N~~, N2~, or mixtures of two or more thereof. The terms "water-in-oil"
emulsion, "water emulsion", "emulsions", "water blended fuel", "emulsified
water fuel" and other variations are interchangeable.
Summary of the Invention
The invention relates to an emulsified water in oil composition comprising:
a. a fuel in the range of about 50% to about 99% by weight of the
composition;
b. a water in the range of about 1 % to about 50% by weight of the
composition;
c. a polyisobutenyl succinic anhydride ( PIBSA) derived emulsifier
wherein the molecular weight of the PIB chain is in the range of about 200 to
5000 and in the range of about 0.01 % to about 10%, or more preferred
0.02% to 5%, or more preferred 0.03% to 1.5%, by weight of the
composition;
d. an alkylamine ethoxylated surfactant in the range of about 0.01
to about 10%, or more preferred 0.02% to 5%, or more preferred 0.03% to
1.5%, by weight of the composition; and
e. optionally at least one of a functional amount of at least one
water-soluble, oil-soluble functional additive dissolved in the emulsified
aqueous phase such as ammonium nitrate.
In particular the surfactant comprises:
(a) at least one of an alkylamine ethoxylated surfactant that can be
a mono- or a di- amine of the general formulae:
R- N(EaH)-(CH2),~ N(E~H)(ECH) or R- N(EaH) (EbH)
wherein R equals straight or branched chained alkyl group, C3 to G30, or
more preferred G10 to C24., and saturated or unsaturated, containing either
0, or 1, or 2 or 3 double bonds;
N = nitrogen atom;
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E is an ethoxylate group, -CH2- CH2-0-
x is either 1, 2, or 3, and
a, b, c, is an integer from 0 to 20 such that: a+b+c = any vale between 1
and 20, more preferably between 1 and 14; and
(b) at least one PIBSA-derived material (with a PIB chain in the
molecular weight in the range of 200 to 5000) comprising:
(1 ) a PIBSA itself;
(2) a PIB succinic acid, wherein this material can be prepared
by reacting a PIBSA with water;
(3) a PIB succinic acid - amine salt wherein this material can
be prepared by reacting the PIB succinic acid as described in (2) with either
an alkyl amine (primary, secondary, or tertiary) or an ethanolamine and/or
ethoxylated amine (A) described above and wherein this salt can be a fully
neutralised or partially neutralised salt;
(4) a PIB succinic aminoalkylester or ester-acid or amine salt
thereof. This material can be prepared by reacting the PIBSA or P1B
succinic acid as described in (1 ) and (2) or ester thereof with a
hydroxylamine or an alkanol amine like ethanolamine and/or ethoxylated
amine (A) described above, wherein the salt can be a fully neutralised or
partially neutralised salt;
(5) a succinimide or succinamide or amide-acid salt thereof
derived by reacting PIBSA with an amine or poly amine;
(6) a succinic ester derived by reacting PIBSA with a polyol; or
(7) combinations thereof.
Further, the invention relates to a process for making a water in oil
emulsion comprising emulsifying a fuel, a water, a PIBSA-derived surfactant,
and an alkylamine ethoxylated surfactant. The invention further relates
to a process to produce an emulsified water in oil composition from a
concentrate comprising emulsifying a portion of a fuel, a portion to
substantially all of a water, substantially all of the PIBSA-derived
surfactant,
substantially all of the alkylamine ethoxylated surfactant to form a
concentrate emulsion; and then diluting the concentrated emulsion with the
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remaining portion of fuel at the time of use.
The water in oil emulsion provides good emulsion stability. The
additive package allows for the water in oil emulsion to be processed more
easily. Further the emulsion has increased storage stability. The water in oil
composition is useful as a fuel for stationary and/or combustion engines
and/or open flame burning apparatus.
Detailec! Descri~ti~n
The invention discloses an additive surfactant package of at least two
surfactants to produce a stable emulsified water in oil composition. The
emulsified water in oil composition employs a PIBSA derived surfactant and
an alkylamine ethoxylated surfactant which are identified by the term additive
surfactant package herein. The additive surfactant package has properties
to lower the interfacial tension at the water/oil interface during emulsion
formation.
The additive surfactant package is in the range of about 0.001 % to
about 15%, in another embodiment about 0.01 % to about 10%, in another
embodiment about 0.05% to about 5%, and in another embodiment about
0.1 % to about 3% by weight of the water in oil composition. The additive
surfactant package maybe used in combination with other surfactants which
may be either ionic or non-ionic surfactant.
The alkylamine ethoxylated surfactant may be derived from a
mono-or a di-amine and has the general formulae:
R- N(EaH)-(CH2) X N(EbH)(E~H) or R- N(EaH)(EbH)
wherein R =, straight or branched chained alkyl group, C8 to C30, preferably
between C10 and C24,more preferably C12 to C22 and most preferable C14
to C20 and saturated or unsaturated, contained either 0, or 1, or 2 or
3 double bonds;
N = nitrogen atom;
E is an ethoxylate group, -CH2- CH2-0-;
x = 1, 2, or 3; and
a, b, c, = any integer between 0 and 20 such that: a+b+c = any value
between 1 and 20, more preferably between 1 and 14.
s
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In another embodiment R is about C12 to about C22, and in another
embodiment about C10 to about C20.
The PIBSA-derived derived surfactant is selected from at least one of
or combinations of:
(1 ) a PIBSA itself.
(2) a PIB succinic acid. This material can be prepared by reacting
a PIBSA with water.
(3) A PIB succinic acid - amine salt. This material can be
prepared by reacting the PIB succinic acid as described in (2) with either an
alkyl amine (primary, secondary, or tertiary), or an ethanolamine and/or
ethoxylated amine (A) described above. This salt can be a fully neutralised
or partially neutralised salt.
(4) A PIB succinic aminoalkylester or ester-acid or amine salt
thereof. This material can be prepared by reacting the PIBSA or PIB
succinic acid as described in (1) and (2) or ester thereof with a
hydroxylamine or an alkanol amine like ethanolamine and/or ethoxylated
amine (A) described above, wherein the salt can be a fully neutralised or
partially neutralised salt.
(5) A succinimide or succinamide or amide-acid salt thereof
derived by reacting PIBSA with an amine or poly amine.
(6) A succinic ester derived by reacting PIBSA with a polyol.
The PIB based surfactant includes both non-ionic, ionic materials or
combinations thereof. The non-ionic materials include PIB succinic acid and
PIB succinamides The ionic materials include PIB succinic acid salts.
These are prepared by reaction of the succinic acid with
diethylethanolamine. Another embodiment of the ionic material is an amidic
acid salt.
The polyisobutylene chain of the PIBSA-derived surfactant has a
number average molecular weight of about 200 to about 5000, in one
embodiment about 1800 to about 2300, in one embodiment about 300 to
about 3000, in one embodiment about 700 to about 1300, in one
embodiment about 800 to about 1000, and in one embodiment from 300 to
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600. The PIBSA from which the PIBSA-derived surfactant is prepared is
characterized by about 1.3 to about 2.5, and in one embodiment about 1.7 to
about 2.1, succinic groups per equivalent weight of the polyisobutylene
substituent. In one embodiment, the hydrocarbyl-substituted carboxylic acid
acylating agent is a polyisobutene-substituted succinic anhydride, the
polyisobutene substituent having a number average molecular weight of
about 1,500 to about 3,000, and in one embodiment about 1,300 to about
2,300, said first polyisobutene-substituted succinic anhydride being
characterized by about 1.3 to about 2.5, and in one embodiment about 1.7 to
about 2.1, in one embodiment about 1.0 to about 1.3, and in one
embodiment about 1.0 to about 1.2 succinic groups per equivalent weight of
the polyisobutene substituent.
Examples of alkylamines disclosed in (2) above include but are not
limited to ethylamine, diethylamine, n-butylamine, di-n-butylamine,
allylamine, isobutylamine, cocoamine, stearylamine, laurylamine,
methyllaurylamine, oleylamine, N-methyloctylamine, dodecylamine, and
octadecylamine. Suitable examples of tertiary monoamines include but are
not limited to trimethylamine, triethylamine, tripropylamine, tributylamine,
monoethyldimethylamine, dimethylpropylamine, dimethyibutyl-amine,
dimethylpentylamine, dimethylhexylamine, dimethylheptylamine, and
dimethyloctylamine.
The amines include but are not limited to hydroxyamines, such as
mono-, di-, and triethanolamine, dimethylethanol amine, diethylethanol
amine, di-(3-hydroxy propyl) amine, N-(3-hydroxybutyl) amine, N-(4-hydroxy
butyl) amine, and N,N-di-(2-hydroxypropyl) amine; alkylene polyamines such
as methylene polyamines, ethylene polyamines, butylene polyamines,
propylene polyamines, pentylene polyamines, and the like. Specific
examples of such polyamines include but are not limited to ethylene diamine,
diethylene triamine, triethylene tetramine, propylene diamine, trimethylene
diamine, tripropylene tetramine, tetraethylene pentamine, hexaethylene
heptamine, pentaethylene hexamine, or a mixture of two or more thereof;
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ethylene polyamine bottoms or a heavy polyamine. In a prefierred
embodiment the alkanolamine is diethyl ethanolamine.
The PIES~4-deri~eed emulsifiier may be present in the water fiuel
emulsion at a concentration ofi 0.01 °/~ to about 10% by weight based
on the
overall weight ofi the emulsion, and in one embodiment about 0.02 to about
5% by weight, and an one embodiment about 0.03 to about 1.5°/~ by
weight.
Examples of suitable aikylamine ethoxylated surfactants include but
are not limited to tallow amirie penta ethoxylate, tallow amine tetra
ethoxylate, tallow amine hexa ethoxylate, tallow amine hepta ethoxylate,
oleyl amine deca ethoxylate, oleyl amine undeca ethoxylate, oleyl amine
nona ethoxylate, oleyl amine dodeca ethoxylate, tris(2-hydroxyethyl)-N-
tallowalkyl-1,3-diaminopropane, oleyl amine penta ethoxylate, oleyl amine
diethoxylate, stearyl alcohol penta ethoxylate and stearyl amine diethoxylate.
In one embodiment the alkylamine ethoxylated surfactant is tallow amine
penta ethoxylate. In one embodiment the alkylamine ethoxylated surfactant
is oleyl amine deca ethoxylate. In one embodiment the alkylamine
ethoxylated surfactant is tris(2-hydroxyethyl)-N-tallowalkyl-1, 3-
diaminopropane. The alkylamine ethoxylated surfactant can be used alone
or in combination.
The ethoxylated amine surfactant may be present in the water fuel
emulsion at a concentration of 0.01 % to about 10% by weight based on the
overall weight of the emulsion, and in one embodiment about 0.02 to about
5% by weight, and an one embodiment about 0.03 to about 1.5% by weight.
Further other surfactants may be used in combination with the
additive surfactant package but do not take the place of the additive
surfactant package and include but are not limited to a) natural fats; b)
Tonics
excluding the additive surfactant package c) co-surfactants; d) fatty acids
and their amine salts; e) ethoxylate alcohols and f) combinations thereof.
The other non ionic and ionic surfactants include but are not limited to
alkyl ethoxylates, ethoxylated alkylphenols, alkyl glucosides, ethoxylated
alcohols, ethoxylated amines, amides derived from fatty acids and/or
alcohols, ethers or fatty alcohols, esters of fatty acids and the like. In
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addition the non-ionic and ionic surfactants have a hydrophilic lipohilic
balance (HL~) in the range of about 2 to about 40, in one embodiment,
about 2 to about 10, in one embodiment about 10 to about 15 and in another
embodiment about 4 to about 8. Examples ofi these non-ionic and ionic
surfactants are disclosed in ~llcCutche~n's Er~~lsifiers arae9 De~erge~~s,
1993, North American ~ International Edition. Preferably the non ionic
surfactants are Neodol 25-3, C12 - C 14 alcohol with two ethoxylates and
Ethomeen C12. The non ionic and ionic surfactants may be used alone or in
combination.
The natural fat surfactants include but are not limited to triglycerides,
hydrolyzed triglycerides, oxidized products of triglycerides, vegetable oils,
refined vegetable oils, used vegetable oils and the like. The preferred
natural fat surfactant is a refined used vegetable oil. The natural fats can
be
used alone or in combination.
The co-surfactant has sufficient polar groups to render the co-
surfactant partially soluble in both phases. The co-surfactants include but
are not limited to alcohols, amines, amides, esters, ketones, ethers and
mixtures thereofi. The co-surfactant has at least 1 to about 24, in another
embodiment about 1 to about 10, in another embodiment about 1 to about 8
carbon atoms. The co-surfactants may be used alone or in combination.
The fatty acids and their amine salts include but are not limited to
N,N-diethyl ethanolamine salts of oleic acid, tall oil fatty acids, stearic
acid,
palmitic acid, lauric acid and the like. The preferable fatty acid and their
amine salt is oleic acid-diethyl ethanol amine salt. The fiatty acids and
their
amine salts can be used alone or in combination.
Fuel
The fiuel comprises hydrocarbonaceous petroleum distillate fuel, non-
hydrocarbonaceous materials that include but are not limited to water, oils,
liquid fuels derived from vegetable sources, liquid fuels derived from
minerals, liquid to gas, and mixtures thereof. Suitable fuels include, but are
not limited to, gasoline, diesel, kerosene, naphtha, aliphatics and paraffin.
The fuel comprises non-hydrocarbonaceous materials include but is not
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limited to alcohois such as methanol, ethanol and the like, ethers such as
diethyl ether, methyl ethyl ether and the like, organo-nitro compounds and
the like; fuels derived from vegetable or mineral sources such as corn,
alfalfa, shale, coal and the like. The fuel also includes but is not limited
to
gas to liquid fuels, Fischer-Tropsch fuels and the like. The fuel also
includes
but is not limited to mixtures of one or more hydrocarbonaceous fuels and
one or more non-hydrocarbonaceous materials. Examples of such mixtures
are combinations of gasoline and ethanol and of diesel fuel and ether and
the like.
In one embodiment, the fuel is any gasoline. Including, but not limited
to a chlorine-free gasoline or a low-chlorine gasoline, or a low sulfur
gasoline
or sulfur-free gasoline and the like.
In one embodiment, the fuel is any diesel fuel. The diesel fuels
include, but are not limited to, those that contain alcohois and esters, has a
sulfur content of up to about 0.05% by weight or sulfur-free, is a chlorine-
free
or low-chlorine diesel fuel and the like. In one embodiment the preferred fuel
is a diesel fuel.
The fuel is present in the emulsified fuel at a concentration of about
50% to about 95% by weight, and in one embodiment about 60% to about
95% by weight, and in one embodiment about 65% to about 85% by weight,
and in one embodiment about 80% to about 90% by weight of the emulsified
fuel.
Water
The water used in the emulsified fuel may be taken from any source.
The water includes but is not limited to tap, deionized, de-ionized to a
conductivity of <30 microsiemens/cm and up to 50% v/v, demineralized,
purified, for example, using reverse osmosis or distillation, and the like.
The
water includes water mixtures that further includes but are not limited to
antifreeze components such as alcohols and glycols, ammonium salts such
as ammonium nitrate, ammonium maleate, ammonium acetate and the like,
and combinations thereof; and other water soluble additives.
to
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The water is present in the emulsified fuel at a concentration of about
1 % to about 50% by weight, in one embodiment about 5°/~ to about
40°/~
being weight, in one embodiment about 5°/~ to about 25°/~ by
weighi, and in
one embodiment about 10°/~ to about 20% by weight of the emulsified
fuel.
In another embodiment the water is present in the emulsified fuel at a
concentration of less than 1 °/~ by weight, in another embodiment less
than
0.5°/~ by weight, in another embodiment less than 0.1 % by weight, and
in
another embodiment in the range of about 0.1 % to about 1 % by weight of
the emulsified fuel. An emulsified water in oil composition can be made with
water at these low levels with the fuel, the emulsifier, the surfactant and
optionally ammonium nitrate and in another embodiment without the
surfactant and with the fuel, the emulsifier and optionally the ammonium
nitrate.
Other Additives
In one embodiment, the emulsified fuel contains a cetane improver.
The cetane improvers that are useful include but are not limited to peroxides,
nitrates, nitrites, nitrocarbamates 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 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 include but are not
limited to methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate,
allyl
nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, isooctyl
nitrate, tert-
butyl nitrate, n-amyl nitrate, isoamyl nitrate, 2-amyl nitrate, 3-amyl
nitrate,
tart-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
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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-
hea~arr~ethylene dinitrate. ~ useful cetane improver is 2-ethylhexyl nitrate.
The concentration of the cetane improver in the emulsified fuel is at
any concentration sufficient to provide the emulsion with the desired cetane
number. In one embodiment, the concentration of the cetane improver is at
a level of up to about 10% by weight, and in one embodiment about 0.05%
to about 10% by weight, and in one embodiment about 0.05% to about 5%
by weight, and in one embodiment about 0.05% to about 1 % by weight of
the emulsified fuel.
In addition to the foregoing materials, other fuel additives that are
known to those skilled in the art may be used in the emulsified fuel. These
include but are not limited to dyes, rust inhibitors such as alkylated
succinic
acids and anhydrides, bacteriostatic agents, gum inhibitors, metal
deactivators, upper cylinder lubricants and the like.
The additives, including the foregoing emulsifiers, may be diluted with
a substantially inert, normally liquid organic solvent such as naphtha,
benzene, toluene, xylene or diesel fuel to form an additive concentrate which
is then mixed with the fuel and water to form the emulsified fuel.
The emulsified fuel may contain up to about 60% by weight organic
solvent, and in one embodiment about 0.01 % to about 50% by weight, and
in one embodiment about 0.01 % to about 20% by weight, and in one
embodiment about 0.1 % to about 5% by weight, and in one embodiment
about 0.1 % to about 3% by weight of the emulsified fuel.
The emulsified fuel may additionally contain an antifreeze agent. The
antifreeze agent is typically an alcohol. Examples include but are not limited
to ethylene glycol, propylene glycol, methanol, ethanol, glycerol and mixtures
of two or more thereof. The antifreeze agent is typically used at a
concentration sufficient to prevent freezing of the water used in the water
fuel emulsion. The concentration is therefore dependent upon the
temperature at which the fuel is stored or used. In one embodiment, the
concentration is at a level of up to about 20% by weight of the emulsified
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fuel, and in one embodiment about 0.1 % to about 20% by weight, and in one
embodiment about 1 % to about 10°/~ by weight of the emulsified fuel.
The total concentration of the additives, in the emulsified fuel is from
about 0.05% to about 80% by weight, and in one embodiment about 0.1 % to
about 20°/~ by weight, and in one embodiment about 0.1 % to about
15°/~ by
weight, and in one embodiment about 0.1 % to about 10% by weight, and in
one embodiment about 0.1 % to about 5°/~ by weight of the emulsified
fuel.
Process
The water in oil emulsion is comprised of a continuous fuel-phase, a
discontinuous water or aqueous phase, an emulsifying amount of an additive
surfactant package and optionally other a surfiactants and optionally a
functional additives such as ammonium nitrate.
In the practice of the present invention the water in oil emulsion is
made by a batch, semi-batch or a continuous process. A concentrate may
be made and used. The process is capable of monitoring and adjusting the
flow rates of the fuel, additive, surfactant, package, surfactants, other
additives andlor water to form a stable emulsion with the desired water
droplet size. The water phase of the emulsified fuel is comprised of droplets
having a mean diameter of about 1.0 microns or less, in another
embodiment about 0.8 microns or less, in another embodiment about 0.5
microns or less, in another embodiment about 0.15 microns or more, in
another embodiment about 1.0 micron to about 0.5 microns, and in another
embodiment about 1.0 micron to about 0.2 microns.
The emulsified fuel may be prepared by the sfieps of mixing the fuel,
the emulsifier, the additive surfactant package, and other oil soluble
additive
using shear techniques to form the fuel additive mixture. Then the fuel
additive mixture is mixed with water and optionally any desired water soluble
additives to form the desired emulsified water blended fuel.
In a batch process the water, the additive surfactant package, the fuel
and optional additives are added to a tank, in the desired amounts. The
mixture is emulsified using an emulsification device in the vessel, or
alternatively the mixture flows from the vessel via a circular line to the
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emulsification device which is external to the vessel, for about 1 to about 20
tank turnovers. The temperature in the range of about ambient temperature
to about 100°C (212°F), and in another embodiment in the range
of about
4°C (40°F) to about 65°C (150°F), and at a
pressure in the range of about
atmospheric pressure to about 10 atmospheres, in another embodiment
about atmospheric pressure to about 80 psi, in another embodiment in the
range of about 1 to about 2 atm (15 psi to about 30 psi).
The continuous process described herein depicts another
embodiment of the invention. The feeds of the fuel, additive surfactant
package, water and optional additives are introduced as discrete feeds or in
the alternative combinations of the discreet feeds. The processing streams
are introduced in or as close to the inlet of the emulsification device as
possible. It is preferable that the emulsifier is added to the fuel as a fuel
emulsifier stream prior to the discreet feeds combining together. The
continuous process generally occurs under ambient conditions. The
continuous process is generally done at atmospheric pressure to about 35
atm (500 psi), in another embodiment in the range of about atmospheric
pressure to about 8 to 9 atm ( about 120 psi), and in another embodiment in
the range of about atmospheric pressure to about 4 atm (about 50 psi). The
continuous process generally occurs at ambient temperature. In one
embodiment the temperature is in the range of about ambient temperature to
about 100 °C (212°F), and in another embodiment in the range of
about 4°C
(40°F) to about 65°C (150°F).
Alternatively, a concentrate is formed and all or substantially all the
water, and water soluble additive and a portion of the fuel and all or
substantially all the surfactant packages is emulsified under shear conditions
to form a concentrate fuel. The emulsified fuel, when used, is then blended
under normal mixing conditions with the remaining portion remaining portion
of the fuel.
The process may be in the form of a containerized equipment unit that
operates automatically. The process can be programmed and monitored
locally at the site of its installation, or it can be programmed and monitored
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from a location remote from the site of its installation. The fully formulated
water fuel blend is optionally dispensed t~ end users at the installation
sifie,
or in another embodiment end users can blend the concentrafied emulsion
with the final portion of fuel. This provides a way to make the water in fuel
emulsions available to end users in wide distribution networks.
The emulsification may occur at shear conditions are greater than
50,000 s'1. However, the c~mposition may be emulsifiied afi shear process
conditions and occurs at a shear rate in the range of less than or equal to
50,000 s 1, and in another embodiment less the about 20,000 s 1, and in
another embodiment less the about 1,000 s'~, and in another embodiment
less than 100 1 s'', and in another embodiment less than 1 s''. if more than
one emulsification step is used, the shear rates of the emulsification steps
can be the same, similar or different, depending on the emulsifier and low
molecular weight surfactant used. The emulsification provides for the
desired particle size and a uniform dispersion of water in the fuel.
The emulsification occurs by any shear method used in the industry
including but not limited to mixing, mechanical mixer agitation, static
mixers,
centrifugal pumps, positive displacement pumps, orifice plates, and the like.
Examples of the devices include but are not limited to an Aquashear,
pipeline static mixers, rotor/stator mixers and the like. The Aquashear is a
low-pressure hydraulic shear device. The Aquashear mixers are available
from Flow Process Technologies Inc.
Engines
The engines that may be operated in accordance with the invention
include all (internal combustion) engines including spark ignited (gasoline)
and compression ignited (diesel) for both mobile including locomotive,
marine, automotive, truck, heavy duty, aviation and the like, and stationary
power plants. The engines may be two-cycle or four-cycle. The engines
may employ conventional after treatment devices. Included are on- and off-
highway engines, including new engines as well as in-use engines.
An open-flame burning apparatus may be operated with the
emulsified water fuel blend of the invention. The open-flame burning
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apparatus may be any open-flame burning apparatus equipped to burn a
liquid fuel. These include domestic, commercial and industrial burners. The
industrial burners include those requirina~ preheating for proper handling and
atomization of the fuel. Also included are oil fired combustion units, oil
fired
power plants, fired lleaters and boilers, and boilers for use in ships
including
deep draft vessels. The fuel burning apparatus may be a boiler for
commercial applications included are boilers for power plants, utility plants,
and large stationary and marine engines. The open-flame fuel burning
apparatus may be an incinerator or a rotary kiln incinerator, liquid injection
kiln, fluidized bed kiln, cement kiln, and the like. Also included are steel
and
aluminium forging furnaces. The open-flame burning apparatus may be
equipped with a flue gas recirculation system.
Specific Embodiments
Example 1
A fuel emulsion is prepared by mixing about 13g of de-ionised water, about
84.5g of a commercially available diesel containing less than 50ppm of
sulphur, about 0.523g of 2300 MW polyisobutylene succinic acid, about
0.068 of diethyl ethanolamine, about 0.562g of tallow amine 7 mole
ethoxylate, about 0.305g of 2-ethylhexylnitrate and about 1 g of diluent oil.
The mixture is sheared by mixing in an Ultra Turrax T25S rotor-stator mixer
for about 3 minutes.
Example 2
The emulsion is the same as Example 1 except the emulsion additionally
contains about 0.12g of aqueous ammonium nitrate with about 54 % actives
in solution.
Example 3
The emulsion is fibs same as Example 1 except the amounts of the following
components in the emulsion are different, about 0.293g of 2300 MW
polyisobutylene succinic acid, about 0.0348 of diethyl ethanolamine and
about 0.9438 of tallow amine 7 mole ethoxylate and about 0.048 of
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ammonium nitrate is added and the emulsion is sheared for about 30
seconds.
Example 4
The emulsion is the same as Example 3 except the emulsion is sheared for
about 2 minutes.
Examtale 5
The emulsion is the same as Example 3 except the emulsion is sheared for
about 5 minutes.
Example 6
The emulsion is the same as Example 1 except the amounts of the following
components in the emulsion are different, about 0.3758 of 2300 MW
polyisobutylene succinic acid, about 0.0438 of diethyl ethanolamine and
about 0.8078 of tallow amine 5 mole ethoxylate and about 0.048 of
ammonium nitrate is added and the emulsion is sheared for about 30
seconds.
Example 7
The emulsion is the same as Example 6 except the emulsion is sheared for
about 5 minutes.
Examale 8
The emulsion is the same as Example 1 except the amounts of the following
components in the emulsion are different, about 0.4048 of 2300 MW
polyisobutylene succinimide derived by reacting PIBSA with a polyamine and
about 0.8078 of tallow amine 5 mole ethoxylate and about 0.048 of
ammonium nitrate is added and the emulsion is sheared for about 3 minutes.
Example 9
The emulsion is the same as Example 1 except the amounts of the following
components in the emulsion are different, about 0.7538 of ~ 000 MW
1~
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polyisobutylene succinimide derived by reacting PIBSA with a polyamine and
about 0.35g of fallow amine 5 mole ethoxylate.
Example 10
The emulsi~n is the same as Example 1 except the amounts ~f the following
components in the emulsion are different, about 0.258g of 1000 MW
polyisobutylene succinic acid, about 0.142g of 550 MW polyisobutylene
succinic acid, about 0.058g of diethyl ethanolamine, about 0.12g of
ammonium nitrate and about 0.561 g of tallow amine 7 mole ethoxylate.
Example 11
The emulsion is the same as Example 1 except the amounts of the following
components in the emulsion are different, about 0.798g of 2300 MW
polyisobutylene succinic acid, about 0.024g of diethyl ethanolamine, about
0.12g of ammonium nitrate, about 0.501 g of tallow amine 7 ethoxylate and
about 0.056g of oleyl amine 10 mole ethoxylate.
Test 1: Centrifuge Test
Approximately 40g of emulsion is placed in calibrated, graduated conical
centrifuge tube and placed in a swing-out rotor type centrifuge. The sample
is centrifuged with a relative centrifugal force of about 4200 for about 5
minutes (as stipulated by the test method, AFNOR prNFM 07-101). The
stability of the emulsion is determined by measuring how much, if any, free
water is produced and the amount of sediment formed. The minimum
requirements are no free water and less than 9 volume % of the emulsion is
sedimented out. The results obtained were Table I:
is
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Table i
Example Sediment Example Sediment
volume /~ volume /~
1 3.75 ~ 2.5
2 1.25 3 '7.5
3 3. 75 9 3. ~'S
4 2.5 10 2.5
2.5 11 2.5
6 6.25
Examples 1-11 produce no free water after 5 minutes. Overall
Examples 1-11 pass the centrifuge test because they produce no free water
5 and the amount of sediment formed is below 9 volume %. The test
demonstrated that stable emulsions are produced.
Test 2: Particle Size
The particle size of an emulsion approximately 24 hours old is determined by
placing about 600m1 of diesel and about 0.5m1 of emulsion in a
Coulter LS230. The sample is exposed to a red laser and the diffraction of
micelles and measured on a detector. The particle size distribution is then
calculated. The results obtained are shown in Table II.
A laser light scattering instrument is used to measure the size
distribution of water particles in PuriNOXT~". When light encounters a
particle, the particle scatters the light. The angular dependence of this
scattered light is dependent on the size of the particle (relative to the
wavelength of the incident light). By measuring the intensity of the scattered
light as a function of angle, and by applying the Mie and Frauhofer scattering
theory, the panicle size distribution can be determined. The Coulter LS230
uses an array of detectors to measure the intensity at 232 angles
simultaneously.
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Particle size of the emulsion was determined by laser light scattering
technique (Coulter LS230 instrument) between 0.04 and >50 micron metres.
Table II
Example /~ sub micronExample /~ sub micron
1 92.5 7 96.9
2 100 8 61.5
3 91.4 9 72.2
4 98 10 13.3
95.3 11 100
6 70.4
5 Generally these measurements illustrate that excellent, substantially
sub-micron emulsions are obtained in all case, with the exception of
example 10. These data, in combination with the centrifuge data, point to
formulations which are close to optimal and those (such as example 10)
which are capable of improvement by alteration of the surfactants (e.g. by
either changing the chemistry or changing the ratio of the surfactants).
Example 12 Formation of a novel ester/acid surfactants made by
reacting PIB succinic anhydride (PIBSA) with fatty amine ethoxylates.
1. Synthesis:
Composition A: a PIBSA, (2300 m.w. Glissopal succinic anhydride),
containing up to 30% solvent, was heated to about 80°C and held at this
temperature while an equimolar quantity of tallow amine 7 mole ethoxylate
was added over about 15 to about 30 minutes. The reaction was followed by
IR until the anhydride peaks disappeared and the ester and carboxylic acid
peaks appeared, indicating that a reaction was complete.
Composition B: A second preparation was carried out identical to
Example A above except that the PIBSA was a 350 m.w. PIBSA.
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Glissopal was obtained from BASF and 350 m.w. PIB was obtained
from TCP.
2. Evaluation
Example 12: A fuel emulsion is prepared by mixing about 13g of de-
ionised water, about 84.48g of a commercially available diesel containing
less than 50ppm of sulphur, about 1.426g of the acid/ester illustrated in
composition A above (i.e. made from 2300 MW polyisobutylene succinate
and tallow amine 7 mole EO), about 0.305g of 2-ethylhexylnitrate, about
0.128 of aqueous (54% concentrate) ammonium nitrate and about 0.67g of
diluent oil. The mixture is sheared by mixing in an Ultra Turrax T25B rotor-
stator mixer for about 3 minutes.
Example 13: The emulsion is the same as Example 12 except the
emulsion was made with 1.426g of the acid ester illustrated in Composition B
above (i.e. made from 350 MW polyisobutylene succinate and tallow amine 7
mole EO).
Test 1: Centrifuge Test
Approximately 40g of emulsion is placed in calibrated, graduated
conical centrifuge tube and placed in a swing-out rotor type centrifuge. The
sample is centrifuged with a relative centrifugal force of about 4200 for
about
5 minutes (as stipulated by the test method, AFNOR prNFM 07-101 ). The
stability of the emulsion is determined by measuring how much, if any, free
water is produced and the amount of sediment formed. The minimum
requirements are no free water and less than 9 volume % of the emulsion is
sedimented out. The results obtained are shown in Table III below.
Table III
Example Sediment volume Example Sediment volume
%
12 6.25 13 2.5
Examples 12 and 13 produce no free water after 5 minutes. Overall
Examples 12 and 13 pass the centrifuge test because they produce no free
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water and the amount of sediment formed is below 9 volume %. The test
demonstrated that stable emulsions are produced.
Test 2: Particle Size
The particle size of an emulsion approximately 24 hours old is
determined by placing about 600 ml of diesel and about 0.5m1 of emulsion in
a Coulter LS230. The sample is exposed to a red laser and the diffraction of
micelles and measured on a detector. The particle size distribution is then
calculated. The results obtained are shown in Table IV below.
A laser light scattering instrument is used to measure the size
distribution of water particles in PuriNOXT"". When light encounters a
particle, the particle scatters the light. The angular dependence of this
scattered light is dependent on the size of the particle (relative to the
wavelength of the incident light). By measuring the intensity of the scattered
light as a function of angle, and by applying the Mie and Frauhofer scattering
theory, the particle size distribution can be determined. The Coulter LS230
uses an array of detectors to measure the intensity at 232 angles
simultaneously.
Particle size of the emulsion was determined by laser light scattering
technique (Coulter LS230 instrument) between 0.04 and >50 micron metres.
Table IV
Example % sub micron Example % sub micron
12 81 13 100
Generally these measurements illustrate that excellent, substantially
sub-micron emulsions are obtained in both case. These data, in
combination with the centrifuge data, point to formulations which are close to
optimal.
From the above description and examples the invention those skilled
in the art may perceive improvements, changes and modifications in the
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invention. Such improvement changes and modifications are intended to be
covered by the appended claims.
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