Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
Method of Controlling By-Products or Pollutants from Fuel Combustion
FIELD OF INVENTION
The present invention relates to a method comprising supplying to the
fuel a dispersion, the dispersion comprises: (a) a mixture of at least two
metal
bases, wherein each metal of the metal bases has an average oxidation state of
(+2) or higher. The method is capable of controlling by-products or pollutants
from fuel combustion.
BACKGROUND OF THE INVENTION
[0001] In
recent years attempts have been made to reduce the amount of
pollutants/emissions released from combustion of fuels.
Examples of
pollutants include sulphur oxides (e.g. sulphur trioxide), nitrogen oxides,
carbon monoxide, carbon dioxide and particulate matter. These pollutants are
known to adversely affect levels of green-house gases or contribute to other
problems, such as, smog. In the case of particulate matter, studies have also
indicated adverse effects on human, animal and plant well being. Other by-
products of fuel combustion include vanadate deposits. Vanadate deposits are
believed to form corrosive low-melting slag that forms deposits. It would be
desirable to combust fuels whilst keeping pollutants to a minimum.
[0002]
International Publication WO 2005/097952 discloses providing a
fuel composition containing a metal base with a solids content of greater than
about 35 wt % of the dispersion. The composition disclosed employs one metal
base per dispersion.
[0003] International
Publication WO 04/026996 discloses a fuel additive
composition capable of reducing vanadate deposits. The composition contains
a metal inorganic oxygen containing compound, a liquid soluble in oil and a
dispersant including fatty acid or ester derivatives thereof.
[0004]
However, none of the dispersions provide an improved method of
reducing numerous pollutants emitted during fuel combustion. Therefore it
would be advantageous to provide a method of controlling pollutants from fuel
combustion. The present invention provides such a method, by providing a
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dispersion which synergistically reduces numerous pollutants emitted during
fuel combustion.
SUMMARY OF THE INVENTION
[0005] The present invention provides a method of controlling by-
products or
pollutants from fuel combustion, comprising combusting a fuel containing a
dispersion, the dispersion comprises: (a) a mixture of at least two metal
bases,
wherein each metal of the metal bases has an average oxidation state of about
(+2) or higher, (b) at least one surfactant; and (c) at least one organic
medium,
wherein the metal bases are uniformly dispersed in the organic medium.
[0006] In one embodiment the invention provides a method of controlling
by-products or pollutants from fuel combustion, comprising combusting a fuel
containing a dispersion, the dispersion comprises: (a) a mixture of at least
three
metal bases, wherein each metal of the metal bases has an average oxidation
state of about (+2) or higher, (b) at least one surfactant; and (c) at least
one
organic medium, wherein the metal bases are uniformly dispersed in the organic
medium.
[0007] In one embodiment the invention provides a dispersion
comprising:
(a) a mixture of at least three metal bases, wherein each metal of the metal
bases has an average oxidation state of about (+2) or higher, (b) at least one
surfactant; and (c) at least one organic medium, wherein the metal bases are
uniformly dispersed in the organic medium.
[0008] In one embodiment the invention provides a composition
comprising:
(i) a fuel; and (ii) a dispersion, wherein the dispersion comprises: (a) a
mixture
of at least two metal bases, wherein each metal of the metal bases has an
average oxidation state of about (+2) or higher, (b) at least one surfactant;
and
(c) at least one organic medium, wherein the metal bases are uniformly
dispersed
in the organic medium.
[0009] In one embodiment the invention provides a composition
comprising:
(i) a fuel; and (ii) a dispersion, the dispersion comprises: (a) a mixture of
at
least three metal bases, wherein each metal of the metal bases has an average
oxidation state of about (+2) or higher, (b) at least one surfactant; and (c)
at
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least one organic medium, wherein the metal bases are uniformly dispersed in
the
organic medium.
[0010] In one embodiment the invention provides for the use of a
dispersion,
(the dispersion comprises: (a) a mixture of at least three metal bases,
wherein
each metal of the metal bases has an average oxidation state of about (+2) or
higher, (b) at least one surfactant; and (c) at least one organic medium,
wherein
the metal bases are uniformly dispersed in the organic medium) in a fuel for
the
reduction of by-products or pollutants formed from fuel combustion.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention provides a method of controlling by-products
or pollutants from fuel combustion as disclosed above. The invention further
provides a composition as disclosed above.
[0012] In one embodiment the invention is other than a water-
containing
emulsion.
[0013] As used herein the term "free of' for all chemistry disclosed herein
except for the metal base, as used in the specification and claims, defines
the
absence of a material except for the amount which is present as impurities,
e.g.,
a trace amount or a non-effective amount. Typically in this embodiment, the
amount present will be less than about 0.05% or less than about 0.005 wt % by
weight of the dispersion.
[0014] As a person skilled in the art will appreciate, impurities in
the metal
base are typically about 1 wt % to about 3 wt % of the metal base. The reason
for the impurities being typically about 1 wt % to about 3 wt % of the metal
base is believed to be due to mining processes. Typically the major impurities
in the metal base include calcium carbonates, silica or silicates.
[0015] In different embodiments the dispersion may be opaque or semi-
translucent or translucent or transparent, or any gradation between such
descriptions.
Fuel
[0016] The fuel comprises a liquid fuel, biofuel, a solid fuel, or mixtures
thereof. In one embodiment the fuel is a solid fuel. In another embodiment the
fuel is a liquid fuel. Examples of a suitable solid fuel include coal.
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[0017] When the fuel comprises a liquid fuel, the liquid fuel may
also be
utilized as a suitable organic medium for preparing the dispersion. Therefore
to
avoid duplication of description a more detailed description of the liquid
fuel is
disclosed below in the organic medium section.
Metal Base
[0018] The dispersion of the metal base comprises di-, tri-, tetra-
valent
metal or a mixture thereof.
[0019] In embodiment the metal base may further comprise a monovalent
metal base. In one embodiment the metal base is derived from a monovalent
metal including lithium, potassium, sodium, copper, or mixtures thereof. In
one embodiment the metal oxidation state of the metal base is other than (+1).
[0020] In another embodiment the average oxidation state of the metal
base
ranges from about (+2) to about (+4), or from about (+2) to about (+3).
Typically the metal of the metal base is a divalent or trivalent metal. In one
embodiment the metal base is derived from a divalent metal including
magnesium, calcium, barium or mixtures thereof. The metal may also have
multiple valences, e.g., mono- or di- or tri- valent with cerium, copper or
iron as
examples. In one embodiment the metal base is derived from a tetravalent
metal including cerium.
[0021] In different embodiments the base of the metal base comprises
oxides, carbonates, bicarbonates, hydroxides, sulphonates, carboxylates (e.g.
C1_30 or C8_24 linear or branched alkyl carboxylates), nitrates, phosphates,
sulphates, sulphites, nitrites, phosphonates, or mixtures thereof.
[0022] In different embodiments the base of the metal base comprises
oxides, carbonates, bicarbonates, hydroxides, sulphonates, carboxylates, or
mixtures thereof. Optionally the metal base further comprises water of
crystallization or adsorped (or absorbed) water. In one embodiment the metal
base is crystalline.
[0023] In different embodiments a first metal base comprises iron
oxide
(Fe203, FeO or Fe304), iron carboxylates (e.g. an octadecanoic acid salt with
iron), magnesium hydroxide, calcium hydroxide, calcium carbonate,
magnesium carbonate, calcium oxide, magnesium oxide or mixtures thereof.
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[0024] In different embodiments a second metal base comprises cerium
oxide (Ce0 or Ce02), cerium sulphonate, iron oxide (Fe203, FeO or Fe304),
iron carboxylates (e.g. an octadecanoic acid salt with iron), copper oxide
(CuO)
or chromium oxides.
[0025] In one embodiment the metal base is substantially free of metal
bases
other than two or three bases selected from the group consisting of magnesium
hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate,
calcium oxide, magnesium oxide, cerium oxide (Ce0 or Ce02), iron oxide
(Fe203, FeO or Fe304), copper oxide (CuO) or chromium oxides, and mixtures
thereof.
[0026] In one embodiment a first metal base contains a metal selected
from
the group consisting of iron, magnesium, calcium and mixtures thereof; and a
second metal base contains a metal selected from the group consisting of
magnesium, calcium, cerium, iron, copper, chromium, and mixtures thereof, with
the proviso that the first metal base is different from the second metal base.
[0027] In one embodiment when there are at least two metal bases in
the
mixture, each metal of the metal bases has an oxidation state of about (+2) or
higher are employed, and the metals may be chosen from:
(i) a first metal base contains a metal selected from the group consisting
of iron, magnesium, calcium and mixtures thereof;
(ii) a second metal base contains a metal selected from the group
consisting of magnesium, calcium, cerium, iron, copper, chromium, and mixtures
thereof, with the proviso that the first metal base is different from the
second
metal base; and
(iii) optionally another metal base other than the metal base of (i) or (ii).
[0028] In one embodiment the first metal base is present in a weight
greater
than the second metal base. The weight of the first metal base present may be
greater than about 50 wt %, or greater than about 75 wt %, or greater than
about
95 wt % of the total amount of metal base present. The weight of the second
metal base present may be less than about 50 wt %, or less than about 25 wt %,
or less than about 5 wt % of the total amount of metal base present.
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[0029] In
one embodiment when there are at least three metal bases in the
mixture, each metal of the metal bases has an oxidation state of about (+2) or
higher are employed, and the metals may be chosen from:
(i) a first metal base contains a metal selected from the group
consisting of iron, magnesium, calcium and mixtures thereof;
(ii) a second metal base contains a metal selected from the group
consisting of magnesium, calcium, cerium, iron, copper,
chromium, and mixtures thereof, with the proviso that the first
metal base is different from the second metal base; and
(iii) at least one other
metal base, wherein the metal of the metal
base is selected from the group consisting of calcium,
magnesium, cerium, iron, copper, chromium, barium, platinum,
lead, manganese, strontium, and mixtures thereof; with the
proviso that the third metal base is a different from the metal
base already employed in (i) and (ii).
[0030] In
one embodiment the metal of the metal base of (iii) is selected from
the group consisting of calcium, magnesium, cerium, iron, copper, chromium,
and mixtures thereof; with the proviso that the third metal base is different
from
a metal base already employed in (i) and (ii).
[0031] When at
least three metal bases are employed in one embodiment two
of the metal bases are derived from a calcium and magnesium base. The third
(or
higher i.e. fourth or fifth) metal base may be derived from a metal selected
from
the group consisting of cerium, iron, copper, chromium, and mixtures thereof.
[0032]
The amount of metal base present in the dispersion, that is, the solids
content, is greater than about 15 wt % and may range from about 17 wt % to
about 90 wt %, or from about 25 wt % to about 80 wt %, or from about 35 wt %
to about 70 wt %, or from about 40 wt % to about 65 wt % of the dispersion.
This amount is determined on the basis of the original dispersion and does not
include any additional diluent into which the dispersion may be subsequently
admixed to form, for instance, a fully formulated lubricating composition, nor
does it include solids or non-volatile components from other sources.
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[0033]
The metal base is typically in the form of a solid and is not
appreciably soluble in the organic medium. In different embodiments the metal
base has a mean particle size in the dispersion ranging from about 20
nanometres to less than about 1 gm, or about 30 nanometres to about 0.7 gm, or
about 50 nanometres to about 0.4 gm, or about 80 nanometres to about 0.3 gm.
[0034]
The metal base generally comprises at least one of oxides,
hydroxides or carbonates.
Examples of a suitable metal base include
magnesium hydroxide, calcium hydroxide, calcium carbonate, magnesium
carbonate, calcium oxide, magnesium oxide, cerium oxide, iron oxide or
mixtures thereof. In one embodiment of the invention the metal base is present
in a mixture, for instance, dolmitic lime, which is commercially available.
[0035] If
the invention further comprises a metal base with an oxidation
state of (+1), examples of a suitable metal base include sodium carbonate,
sodium bicarbonate, potassium carbonate, potassium bicarbonate, potassium
hydroxide, sodium hydroxide, anhydrous lithium hydroxide, lithium hydroxide
monohydrate, lithium carbonate, lithium oxide or mixtures thereof.
[0036] In
one embodiment the dispersion further comprises a co-ordination
compound, such as, ferrocene (cyclopentadienyl based), carboxylates or
sulphonates.
Surfactant
[0037]
The surfactant includes an ionic (cationic or anionic) or non-ionic
compound. Generally, the surfactant stabilises the dispersion of the metal
base
in the organic medium.
[0038]
Suitable surfactant compounds include those with a hydrophilic
lipophilic balance (HLB) ranging from about 1 to about 40, or about 1 to about
20, or about 1 to about 18, or about 2 to about 16, or about 2.5 to about 15.
In
different embodiments the HLB may be about 11 to about 14, or less than about
about 10 such as about 1 to about 8, or about 2.5 to about 6. Combinations of
surfactants may be used with individual HLB values outside of these ranges,
provided that the composition of a final surfactant blend is within these
ranges.
When the surfactant has an available acidic group, the surfactant may become
the
metal salt of the acidic group and where the metal is derived from the metal
base.
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[0039]
Examples of surfactants suitable for the invention are disclosed in
McCutcheon's Emulsifiers and Detergents, 1993, North American &
International Edition.
Generic examples include alkanolamides,
alkylarylsulphonates, amine oxides, poly(oxyalkylene) compounds, including
block copolymers comprising alkylene oxide repeat units (e.g., PluronicTm),
carboxylated alcohol ethoxylates, ethoxylated alcohols, ethoxylated alkyl
phenols, ethoxylated amines and amides, ethoxylated fatty acids, ethoxylated
fatty esters and oils, fatty esters, glycerol esters, glycol esters,
imidazoline
derivatives, phenates, lecithin and derivatives, lignin and derivatives,
monoglycerides and derivatives, olefin sulphonates, phosphate esters and
derivatives, propoxylated and ethoxylated fatty acids or alcohols or alkyl
phenols, sorbitan derivatives, sucrose esters and derivatives, sulphates or
alcohols or ethoxylated alcohols or fatty esters, polyisobutylene
succinicimide
and derivatives.
[0040] In one
embodiment the surfactant comprises polyesters as defined in
column 2, line 44 to column 3, line 39 of US 3,778,287. Examples of suitable
polyester surfactants are prepared in US 3,778,287 as disclosed in Polyester
Examples A to F (including salts thereof).
[0041] In
one embodiment the surfactant is a hydrocarbyl substituted aryl
sulphonic acid (or sulphonate) of an alkali metal, alkaline earth metal or
mixtures
thereof The aryl group of the aryl sulphonic acid may be phenyl or naphthyl.
In
one embodiment the hydrocarbyl substituted aryl sulphonic acid comprises alkyl
substituted benzene sulphonic acid.
[0042]
The hydrocarbyl (especially an alkyl) group typically contains about 8
to about 30, or about 10 to about 26, or about 10 to about 15 carbon atoms. In
one embodiment the surfactant is a mixture of Cio to C15 alkylbenzene
sulphonic
acids. Examples of sulphonates include dodecyl and tridecyl benzene sulfonates
or condensed naphthalenes or petroleum sulfonates, as well as sulphosuccinates
and derivatives.
[0043] In one
embodiment the surfactant is in the form of a neutral or
overbased surfactant, typically salted with an alkali or alkaline earth metal.
The
alkali metal includes lithium, potassium or sodium; and the alkaline earth
metal
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includes calcium or magnesium. In one embodiment the alkali metal is sodium.
In one embodiment the alkaline earth metal is calcium.
[0044] In one embodiment the surfactant is a derivative of a
polyolefin.
Typical examples of a polyolefin include polyisobutene; polypropylene;
polyethylene; a copolymer derived from isobutene and butadiene; a copolymer
derived from isobutene and isoprene; or mixtures thereof
[0045] Typically the derivative of a polyolefin comprises a
polyolefin-
substituted acylating agent optionally further reacted to form an ester and/or
aminoester. The acylating agent may be prepared from carboxylic reactants
(which when reacted with a polyolefin give the desired acylating agent, i.e.
substrate
for the surfactant). The carboxylic reactants include functional groups, such
as a
carboxylic acid or anhydride thereof. Examples of carboxylic reactants include
an alpha, beta-unsaturated mono- or polycarboxylic acid, anhydride ester or
derivative thereof Examples of carboxylic reactants thus include (meth)
acrylic
acid, methyl (meth) acrylate, maleic acid or anhydride, fumaric acid, itaconic
acid or
anhydride, or mixtures thereof, each of which may typically be in the form of
the
saturated materials (e.g. succinic anhydride) after reaction with the
polyolefin.
[0046] In one embodiment the polyolefin is a derivative of
polyisobutene
with a number average molecular weight of at least 250, 300, 500, 600, 700, or
800, to 5000 or more, often up to 3000, 2500, 1600, 1300, or 1200. Typically,
less than about 5% by weight of the polyisobutylene used to make the
derivative
molecules have Mn less than about 250, more often the polyisobutylene used to
make the derivative has Mn of at least about 800. The polyisobutylene used to
make the derivative preferably contains at least about 30% terminal vinylidene
groups, more often at least about 60% or at least about 75% or about 85%
terminal vinylidene groups. The polyisobutylene used to make the derivative
may have a polydispersfty, Mw/Mn, greater than about 5, more often from
about 6 to about 20.
[0047] In various embodiments, the polyisobutene is substituted with
succinic
anhydride, the polyisobutene substituent having a number average molecular
weight ranging from about 1,500 to about 3,000, or about 1,800 to about 2,300,
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or about 700 to 1 about 700, or about 800 to about 1000. The ratio of succinic
groups per equivalent weight of the polyisobutene typically ranges from about
1.3 to about 2.5, or about 1.7 to about 2.1, or about 1.0 to about 1.3, or
about 1.0
to about 1.2.
[0048] In one embodiment the surfactant is polyisobutenyl-dihydro-2,5-
furandione ester with pentaerythritol or mixtures thereof In one embodiment
the
surfactant is a polyisobutylene succinic anhydride derivative such as a
polyisobutylene succinimide or derivatives thereof In one embodiment the
surfactant is substantially free to free of a basic nitrogen.
[0049] Other typical derivatives of polyisobutylene succinic anhydrides
include hydrolysed succinic anhydrides, esters or diacids. Polyisobutylene
succan derivatives are preferred to make the metal base dispersions. A large
group of polyisobutylene succinic anhydride derivatives are taught in US
4,708,753, and US 4,234,435.
[0050] In another embodiment the surfactant comprises a salixarene (or
salixarate if in the form of a metal salt). The salixarene is defined as an
organic
substrate of a salixarate. The salixarene may be represented by a
substantially
linear compound comprising at least one unit of the formulae (I) or (II):
(R2)j
(I)
L/
C00R3
Or
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(OH)f
(H)
(R4)g
each end of the compound having a terminal group of formulae (III) or (IV):
(OH)f
(R2)i
(R4)g
COOR3
(III) (IV)
such groups being linked by divalent bridging groups, which may be the same
or different for each linkage; wherein f is about 1, 2 or 3, in one embodiment
about 1 or 2; R2 is hydroxyl or a hydrocarbyl group and j is about 0, 1, or 2;
R3
is hydrogen or a hydrocarbyl group; R4 is a hydrocarbyl group or a substituted
hydrocarbyl group; g is about 1, 2 or 3, provided at least one R4 group
contains
8 or more carbon atoms; and wherein the compound on average contains at
least one of unit (I) or (III) and at least one of unit (II) or (IV) and the
ratio of
the total number of units (I) and (III) to the total number of units of (II)
and
(IV) in the composition is about 0.1:1 to about 2:1.
[0051] The U group in formulae (I) and (III) may be an ¨OH or an ¨NH2
or
-NHR1 or ¨N(R1)2 group located in one or more positions ortho, meta, or para
to the -COOR3 group. R1 is a hydrocarbyl group containing 1 to 5 carbon
atoms. When the U group comprises a ¨OH group, formulae (I) and (III) are
derived from 2-hydroxybenzoic acid (often called salicylic acid), 3-
hydroxybenzoic acid, 4-hydroxybenzoic acid or mixtures thereof. When U is a
¨NH2 group, formulae (I) and (III) are derived from 2-aminobenzoic acid (often
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called anthranilic acid), 3-aminobenzoic acid, 4-aminobenzoic acid or mixtures
thereof.
[0052] The divalent bridging group, which may be the same or
different in
each occurrence, includes an alkylene or methylene bridge such as -CH2- or ¨
CH(R)- and an ether bridge such as -CH2OCH2- or ¨CH(R)OCH(R)- where R is
an alkyl group having 1 to 5 carbon atoms and where the methylene and ether
bridges are derived from formaldehyde or an aldehyde having 2 to 6 carbon
atoms.
[0053] Often the terminal group of formulae (III) or (IV) further
contains 1
or 2 hydroxymethyl groups ortho to a hydroxy group. In one embodiment of
the invention hydroxymethyl groups are present. In one embodiment of the
invention hydroxymethyl groups are not present. A more detailed description
of salixarene and salixarate chemistry is disclosed in EP 1 419 226 B1,
including methods of preparation as defined in Examples 1 to 23 (page 11, line
42 to page 13, line 47).
[0054] In one embodiment the surfactant is substantially free of, to
free of, a
fatty acid or derivatives thereof, such as esters. In one embodiment the
surfactant is other than a fatty acid or derivatives thereof
[0055] In one embodiment the surfactant comprises at least of
hydrocarbyl
substituted aryl sulphonic acids, derivatives of polyolefins, polyesters or
salixarenes (or salixarates).
[0056] In different embodiments the surfactant is substantially free
of, to
free of, phospholipids, (such as lecithin) and/or amino acids (such as
sarcosines).
[0057] In one embodiment the surfactant has a molecular weight of less than
1000, in another embodiment less than about 950, for example, about 250, about
300, about 500, about 600, about 700, or about 800.
[0058] The amount of surfactant and metal base in the dispersion may
vary as
is shown in Table 1, the balance being the organic medium and optionally
water.
In one embodiment the amount of the organic medium present in the dispersion
varies from about 25 wt % to about 55 wt %.
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Table 1
Embodiments (wt % of dispersion)
Additive 1 2 3 4
Metal Base 17-90 25-80 35-70 40-
65
Surfactant 0.01-30 1-30 2-30 5-
25
Organic Medium
[0059]
The organic medium may comprise an oil of lubricating viscosity, a
liquid fuel, a hydrocarbon solvent or mixtures thereof. Typically the organic
solvent comprises an oil of lubricating viscosity or a liquid fuel.
[0060]
Optionally the organic medium contains water, typically up to about 1
wt %, or about 2 wt % or about 3 wt % of the dispersion. In different
embodiments the organic medium is substantially free of, to free of, water.
Oils of Lubricating Viscosity
[0061] In
one embodiment the organic medium comprises an oil of
lubricating viscosity. Such oils include natural and synthetic oils, oil
derived
from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined and
re-refined oils and mixtures thereof.
[0062] Unrefined
oils are those obtained directly from a natural or synthetic
source generally without (or with little) further purification treatment.
[0063]
Refined oils are similar to the unrefined oils except they have been
further treated in one or more purification steps to improve one or more
properties. Purification techniques are known in the art and include solvent
extraction, secondary distillation, acid or base extraction, filtration,
percolation
and the like.
[0064] Re-
refined oils are also known as reclaimed or reprocessed oils, and
are obtained by processes similar to those used to obtain refined oils and
often
are additionally processed by techniques directed to removal of spent
additives
and oil breakdown products.
[0065]
Natural oils useful in making the inventive lubricants include animal
oils, vegetable oils (e.g., castor oil, lard oil), mineral lubricating oils
such as
liquid petroleum oils and solvent-treated or acid-treated mineral lubricating
oils
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of the paraffinic, naphthenic or mixed paraffinic-naphthenic types and oils
derived from coal or shale or mixtures thereof.
[0066] Synthetic lubricating oils are useful and include hydrocarbon
oils,
such as, polymeric tetrahydrofurans, polymerised and interpolymerised olefins
(e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers);
poly(1-hexenes), poly(1-octenes), poly(1-decenes), and mixtures thereof; alkyl-
benzenes (e.g. dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-
ethylhexyl)-benzenes); polyphenyls (e.g., biphenyls, terphenyls, alkylated
polyphenyls); alkylated diphenyl ethers and alkylated diphenyl sulphides and
the derivatives, analogs and homologs thereof or mixtures thereof.
[0067] Other synthetic lubricating oils include. Synthetic oils may
be
produced by Fischer-Tropsch reactions and typically may be hydroisomerised
Fischer-Tropsch hydrocarbons or waxes.
[0068] Oils of lubricating viscosity may also be defined as specified
in the
American Petroleum Institute (API) Base Oil Interchangeability Guidelines.
The five base oil groups are as follows: Group I (sulphur content >0.03 wt %,
and/or <90 wt % saturates, viscosity index 80-120); Group II (sulphur content
<0.03 wt %, and >90 wt % saturates, viscosity index 80-120); Group III
(sulphur content <0.03 wt %, and >90 wt % saturates, viscosity index >120);
Group IV (all polyalphaolefins (PA0s)); and Group V (all others not included
in Groups I, II, III, or IV). The oil of lubricating viscosity comprises an
API
Group I, Group II, Group III, Group IV, Group V oil and mixtures thereof.
Often the oil of lubricating viscosity is an API Group I, Group II, Group III,
Group IV oil and mixtures thereof. Alternatively the oil of lubricating
viscosity
is often an API Group I, Group II, Group III oil or mixtures thereof
Liquid Fuel
[0069] The liquid fuel is normally a liquid at ambient conditions.
The liquid
fuel includes a hydrocarbon fuel, a biofuel (such as, bio-diesel), a
nonhydrocarbon fuel, or a mixture thereof. The hydrocarbon fuel may be a
petroleum distillate such as a gasoline as defined by ASTM (American Society
for Testing and Materials) specification D4814 or a diesel fuel as defined by
ASTM specification D975. In an embodiment the liquid fuel is a gasoline, and
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in another embodiment the liquid fuel is a leaded gasoline, or a nonleaded
gasoline. In another embodiment the liquid fuel is a diesel fuel. The
hydrocarbon fuel includes a hydrocarbon prepared by a gas to liquid process
for
example hydrocarbons prepared by a process such as the Fischer-Tropsch
process. The nonhydrocarbon fuel includes an oxygen containing composition
(often referred to as an oxygenate), an alcohol, an ether, a ketone, an ester
of a
carboxylic acid, a nitroalkane, or a mixture thereof The nonhydrocarbon fuel
includes methanol, ethanol, methyl t-butyl ether, methyl ethyl ketone,
transesterified oils and/or fats from plants and animals such as rapeseed
methyl
ester and soybean methyl ester, and nitromethane. Mixtures of hydrocarbon and
nonhydrocarbon fuels include gasoline and methanol and/or ethanol, diesel fuel
and ethanol, and diesel fuel and a transesterified plant oil such as rapeseed
methyl ester. In one embodiment the liquid fuel is a nonhydrocarbon fuel or a
mixture thereof.
[0070] The dispersion may be used as a sole additive for a fuel
composition.
In one embodiment the dispersion is used as one additive in combination with
other performance additives to provide a fuel composition. In one embodiment
the invention provides a fuel composition comprising (i) a dispersion
comprising: (a) a metal base; (b) a surfactant; and (c) an organic medium in
which the metal base is dispersed; (ii) an oil of lubricating viscosity; and
(iii)
other performance additives.
[0071] The fuel composition may thus comprise an oil of lubricating
viscosity as defined above, in addition to the amount which may be present as
the organic medium of the dispersion.
Other Performance Additives
[0072] The fuel composition optionally comprises other performance
additives. The other performance additives comprise at least one of metal
deactivators, detergents, dispersants, friction modifiers, corrosion
inhibitors,
antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal
swelling agents, biocides, anti-foulants, flow improvers (include
polymethacrylates, maleic anhydride-styrene interpolymers, polyalphaolefins,
and ethylene vinyl acetates), cold flow improvers, or mixtures thereof.
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Typically, fully-formulated fuel will contain one or more of these performance
additives.
[0073]
Performance additives such as antiwear agents are typically included
in a fuel in 2-stroke marine diesel cylinder lubricant.
Demulsifiers
[0074]
Demulsifiers are known. In one embodiment the dispersion further
comprises demulsifiers, or mixtures thereof. Examples of demulsifiers include
trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene
oxides and (ethylene oxide-propylene oxide) polymers, alkoxylated alkyl
phenol resins or mixtures thereof.
Dispersants
[0075]
Dispersants are often known as ashless-type dispersants because,
prior to mixing in a lubricating oil composition, they do not contain ash-
forming metals and they do not normally contribute any ash forming metals
when added to a lubricant. Dispersants also include polymeric dispersants.
Ashless type dispersants are characterised by a polar group attached to a
relatively high molecular weight hydrocarbon chain.
Typical ashless
dispersants include N-substituted long chain alkenyl succinimides. Examples
of N-substituted long chain alkenyl succinimides include polyisobutylene
succinimide with number average molecular weight of the polyisobutylene
substituent in the range 350 to 5000, or 500 to 3000. Succinimide dispersants
and their preparation are disclosed, for instance in US Patent 4,234,435.
Succinimide dispersants are typically the imide formed from a polyamine,
typically a poly(ethyleneamine).
[0076] In one
embodiment the invention further comprises at least one
dispersant derived from polyisobutylene succinimide with number average
molecular weight in the range 350 to 5000, or 500 to 3000. The polyisobutylene
succinimide may be used alone or in combination with other dispersants.
[0077] In
one embodiment the invention further comprises at least one
dispersant derived from polyisobutylene, an amine and zinc oxide to form a
polyisobutylene succinimide complex with zinc.
The polyisobutylene
succinimide complex with zinc may be used alone or in combination.
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[0078]
Another class of ashless dispersant is Mannich bases. Mannich
dispersants are the reaction products of alkyl phenols with aldehydes
(especially formaldehyde) and amines (especially polyalkylene polyamines).
The alkyl group typically contains at least 30 carbon atoms.
[0079] In one
embodiment the dispersant includes a polyisobutylene-amine
as described in U.S. Patents 5,567,845 and 5,496,383; and commercially
available
from BASF.
[0080]
The dispersants may also be post-treated by conventional methods by
a reaction with any of a variety of agents. Among these are boron sources such
as boric acid or borates, urea, thiourea, dimercaptothiadiazoles, carbon
disulphide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted
succinic anhydrides, maleic anhydride, nitriles, epoxides, and phosphorus
compounds.
Detergents
[0081] The fuel
composition optionally further comprises neutral or
overbased detergents.
Suitable detergent substrates include sulphonates,
salixarates, salicylates, carboxylates, phosphorus acid salts, mono- and/or di-
thiophosphoric acid salts, phenates including alkyl phenates and sulphur
coupled alkyl phenates, or saligenins.
[0082] In different
embodiments, the fuel composition further comprises at
least one of sulphonates and phenates. When present, the detergents are
typically overbased. The ratio of TBN delivered by the dispersion to that
delivered by the detergent may range from 1:99 to 99:1, or 15:85 to 85:15.
Antioxidant
[0083] Antioxidant
compounds are known and include an amine antioxidant
(such as an alkylated diphenylamine), a hindered phenol, a molybdenum
dithiocarbamate, and mixtures thereof. Antioxidant compounds may be used
alone or in combination.
[0084]
The hindered phenol antioxidant often contains a secondary butyl
and/or a tertiary butyl group as a sterically hindering group. The phenol
group
is often further substituted with a hydrocarbyl group and/or a bridging group
linking to a second aromatic group. Examples of suitable hindered phenol
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antioxidants include 2,6-di-tert-butylpheno1, 4-methyl-2,6-di-tert-
butylphenol,
4-ethyl-2,6-di-tert-butylphenol, 4-propy1-2,6-di-tert-butylphenol or 4-buty1-
2,6-
di-tert-butylphenol 2,6-di-tert-butylphenol. In one embodiment the hindered
phenol antioxidant is an ester and may include, e.g., IrganoxTM L-135 from
Ciba. A more detailed description of suitable ester-containing hindered phenol
antioxidant chemistry is found in US Patent 6,559,105.
[0085] Suitable examples of molybdenum dithiocarbamates which may be
used as an antioxidant include commercial materials sold under the trade names
such as Vanlube 822TM and MolyvanTM A from R. T. Vanderbilt Co., Ltd., and
Adeka Sakura-LubeTM S-100, S-165 and S-600 from Asahi Denka Kogyo K. K
and mixtures thereof.
Antiwear Agent
[0086] The fuel composition optionally further comprises at least one
antiwear agent. Examples of suitable antiwear agents include a sulphurised
olefin, sulphur-containing ashless anti-wear
additives, metal
dihydrocarbyldithiophosphates (such as zinc dialkyldithiophosphates),
thiocarbamate-containing compounds, such as thiocarbamate esters,
thiocarbamate amides, thiocarbamic ethers, alkylene-coupled thiocarbamates,
and bis(S-alkyldithiocarbamyl) disulphides.
[0087] The dithiocarbamate-containing compounds may be prepared by
reacting a dithiocarbamic acid or salt with an unsaturated compound. The
dithiocarbamate containing compounds may also be prepared by simultaneously
reacting an amine, carbon disulphide and an unsaturated compound. Generally,
the reaction occurs at a temperature from 25 C to125 C. US Patents 4,758,362
and 4,997,969 describe dithiocarbamate compounds and methods of making
them.
[0088] Examples of suitable olefins that may be sulphurised to form
an the
sulphurised olefin include propylene, butylene, isobutylene, pentene, hexane,
heptene, octane, nonene, decene, undecene, dodecene, undecyl, tridecene,
tetradecene, pentadecene, hexadecene, heptadecene, octadecene, octadecenene,
nonodecene, eicosene or mixtures thereof. In one embodiment, hexadecene,
heptadecene, octadecene, octadecenene, nonodecene, eicosene or mixtures
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thereof and their dimers, trimers and tetramers are especially useful olefins.
Alternatively, the olefin may be a Diels-Alder adduct of a diene such as
1,3-butadiene and an unsaturated ester such as butyl(meth)acrylate.
[0089]
Another class of sulphurised olefin includes fatty acids and their
esters. The fatty acids are often obtained from vegetable oil or animal oil
and
typically contain 4 to 22 carbon atoms. Examples of suitable fatty acids and
their esters include triglycerides, oleic acid, linoleic acid, palmitoleic
acid or
mixtures thereof. Often, the fatty acids are obtained from lard oil, tall oil,
peanut oil, soybean oil, cottonseed oil, sunflower seed oil or mixtures
thereof.
In one embodiment fatty acids and/or ester are mixed with olefins.
[0090] In
an alternative embodiment, the ashless antiwear agent may be a
monoester of a polyol and an aliphatic carboxylic acid, often an acid
containing
12 to 24 carbon atoms. Often the monoester of a polyol and an aliphatic
carboxylic acid is in the form of a mixture with a sunflower oil or the like,
which may be present in the friction modifier mixture from 5 to 95, in
different
embodiments from 10 to 90, or 20 to 85, or 20 to 80 weight percent of said
mixture. The aliphatic carboxylic acids (especially a monocarboxylic acid)
which form the esters are those acids typically containing 12 to 24 or 14 to
20
carbon atoms. Examples of carboxylic acids include dodecanoic acid, stearic
acid, lauric acid, behenic acid, and oleic acid.
[0091]
Polyols include diols, triols, and alcohols with higher numbers of
alcoholic OH groups. Polyhydric alcohols include ethylene glycols, including
di-, tri- and tetraethylene glycols; propylene glycols, including di-, tri-
and
tetrapropylene glycols; glycerol; butane diol; hexane diol; sorbitol;
arabitol;
mannitol; sucrose; fructose; glucose; cyclohexane diol; erythritol; and
pentaerythritols, including di- and tripentaerythritol. Often the polyol is
diethylene glycol, triethylene glycol, glycerol, sorbitol, pentaerythritol or
dip entaerythritol.
[0092]
The commercially available monoester known as "glycerol
monooleate" is believed to include 60 + 5 percent by weight of the chemical
species glycerol monooleate, along with 35 + 5 percent glycerol dioleate, and
less than 5 percent trioleate and oleic acid.
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[0093] Other performance additives such as corrosion inhibitors
including
octylamine octanoate, condensation products of dodecenyl succinic acid or
anhydride and a fatty acid such as oleic acid with a polyamine; metal
deactivators including derivatives of benzotriazoles, 1,2,4-triazoles,
benzimidazoles, 2-alkyldithiobenzimidazoles or 2-alkyldithiobenzothiazoles;
foam inhibitors including copolymers of ethyl acrylate and 2-
ethylhexylacrylate
and optionally vinyl acetate;; pour point depressants including esters of
maleic
anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides; and
friction modifiers including fatty acid derivatives such as amines, esters,
epoxides, fatty imidazolines, condensation products of carboxylic acids and
polyalkylene-polyamines and amine salts of alkylphosphoric acids may also be
used in the lubricant composition.
Process for Dispersion Preparation
[0094] The dispersion may be prepared by physical processes, that is,
by
any one or more of various physical processes, i.e., physical processing
steps.
Examples of physical process include agitating, milling, grinding, crushing or
mixtures thereof. Typically the process grinds the metal base to a mean
average
particle size of at least 10 nanometres to less than 1 gm. Milling processes
include using a rotor stator mixer, a vertical bead mill, a horizontal bead
mill,
basket milling, ball mill, pearl milling or mixtures thereof In one
embodiment,
the physical processes for preparing the dispersion comprise using a vertical
or
horizontal bead mill.
[0095] In one embodiment the invention further provides a process for
preparing a dispersion comprising the steps of:
(1) mixing (a) at least two metal bases, wherein each metal of the metal
bases has an average oxidation state of about (+2) or higher; (b) a surfactant
and
(c) a organic medium, to form a slurry;
(2) grinding the slurry of step (1) to form a dispersion.
[0096] In another embodiment the dispersion may be prepared by
forming a
single metal dispersion as taught in WO 2005/097952, with the additional step
of combining multiple single metal base dispersions (by mixing them together)
to form a dispersion comprising at least two metal bases, wherein each metal
of
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the metal bases has an average oxidation state of about (+2) or higher; (b) a
surfactant and (c) a organic medium. When a dispersion is prepared by
combining multiple single metal base dispersions, it is common for all single
metal base dispersions to comprise the same or compatible surfactant
compounds and organic media. If the surfactants and organic media are not
compatible, unstable dispersions may be formed.
[0097] In
different embodiments the milling process may be carried out in a
vertical or horizontal bead mill. Either bead mill processes cause the
reduction
of particle size of the metal base by high energy collisions of the metal base
with at least one bead; and/or other metal base agglomerates, aggregates,
solid
particles; or mixtures thereof. The beads typically have a mean particle size
and mass greater than the desired mean particle size of the metal base. In
some
instances the beads are a mixture of different mean particle size. The beads
used in the grinding may be of materials known to those skilled in the art,
such
as metal ceramic, glass, stone, or composite materials.
[0098]
The mill typically contains beads present at least about 40 vol %, or
at least about 60 vol % of the mill. A range include for example about 60 vol
% to about 95 vol %. A more detailed description of making the dispersion is
disclosed in US Patent Application Number US05/010631.
Industrial Application
[0099]
The method of controlling by-products or pollutants from fuel
combustion dispersion is useful for numerous open or closed flame combustion
systems.
Suitable combustion systems include power stations, internal
combustion engines, industrial and marine compression engines and turbines
(commonly combusting a distillate, residual or heavy fuel oils).
[00100] In different embodiments a suitable dispersion is added to the fuel in
ranges from about 1 ppm to about 10,000 ppm, or from about 20 ppm to about
7500 ppm, or from about 100 ppm to about 5000 ppm, or from about 200 ppm to
about 3000 ppm, or from about 500 ppm to about 2000 ppm.
[00101] In one embodiment, the invention provides a method of controlling
by-products or pollutants from fuel combustion, comprising supplying thereto a
fuel comprising the dispersion as described herein. The use of the dispersion
in
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a fuel may impart a means of controlling by-products or pollutants from fuel
combustion. Typically, the by-products or pollutants from fuel combustion
comprise two or more properties from modified sulphur oxide emissions,
modified nitrogen oxide emissions, modified particulate matter production,
modified vanadate production or mixtures thereof. In one embodiment the fuel
dispersion comprises a calcium base and the base is capable of modifying
sulphur oxide emissions, and particulate matter production. In one embodiment
the fuel dispersion comprises a magnesium base and the base is capable of
modifying vanadate production, sulphur oxide emissions, and particulate matter
production.
[00102] The following examples provide an illustration of the invention.
These examples are non exhaustive and are not intended to limit the scope of
the invention.
EXAMPLES
Preparative Examples of Dispersions
[00103] A series of dispersions (Preparative Examples 1 to 3) containing a
metal base, an organic medium and a surfactant were prepared from a slurry
weighing about 15 kg are prepared using a lab scale Dyno-Mill ECM Multi-Lab
horizontal bead mill commercially available from W.A.B. A.G., Basel, using
0.3mm 0 zirconia / yttria beads and a residence time of about 10 minutes at a
tip speed of about 8 ms-1. Where appropriate, the mean particle size of the
dispersion particles is determined after cooling by Coulter LS230 Particle
Size
Analyser. The dispersions prepared are pourable.
Preparative Example 1: Magnesium Oxide Dispersion
[00104] A dispersion is prepared by milling about 50 wt % Magnesium
oxide, Magchem 40 ex Martin Marietta, in the presence of about 40 wt % 100
N base oil and about 10 wt % of an alkyl benzene sulphonic acid surfactant.
Preparative Example 2: Iron Oxide Dispersion
[00105] A dispersion is prepared by milling about 70 wt % of iron oxide
(Fe203) commercially available from Bayer as Bayferrox0160, about 18 wt %
of 100 N base oil and about 12 wt % of an alkyl benzene sulphonic acid
surfactant.
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Preparative Example 3: Cerium Oxide Dispersion
[00106] A dispersion is prepared by milling about 50 wt % of cerium oxide
(Ce0), about 40 wt % of 100 N base oil and about 10 wt % of a surfactant
(polyolefin amino ester esterified with 2-(dimethylamino)ethanol).
Example 1: Three Metal Dispersion
[00107] A three metal dispersion is prepared by mixing the product of
Preparative Example 1 with a commercially available cerium sulphonate
powder and a octdecanoic acid salt of iron. The final product has a metal
weight ratio of magnesium:cerium:iron of about 150:10:5. The product forms a
stable dispersion that shows no significant stratification after 12 weeks.
Example 2: Three Metal Dispersion
[00108] A three metal dispersion is prepared by blending portions of the
products formed in Preparative Examples 1 to 3. The final product has a metal
weight ratio of magnesium:cerium:iron of about 150:10:5. The product forms a
stable dispersion that shows no significant stratification after 12 weeks The
dispersion has greater than about 85 % of dispersion particles have a particle
size of less than about 0.46 microns.
Example 3: Three Metal Dispersion
[00109] A three metal dispersion is prepared by blending in a powder form
magnesium oxide, calcium hydroxide and iron oxide (Fe203). The resultant
three metal powder is then added to about 10 wt % of a succinimide surfactant,
and about 39.6 wt % of SN 100 base oil and about 0.4 wt % of a demulsifier.
The final dispersion contains 37.5 wt % magnesium oxide, about 10.5 wt %
calcium hydroxide and about 2 wt % iron oxide. The resultant dispersion is
pourable and with a mean particle size of about 0.14 to about 0.2 microns.
Fuel Compositions 1-3
[00110] Examples 1 to 3 are treated into a liquid fuel at about 1000 ppm
respectively. The resultant fuel is combusted and the use of the dispersion
provides reduces by-products or pollutants from fuel combustion.
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Fuel Compositions 4-6
[00111] Examples 4 to 6 are treated into a liquid fuel at about 1300 ppm
respectively. The resultant fuel is combusted and the use of the dispersion
provides reduces by-products or pollutants from fuel combustion.
Fuel Compositions 7-9
[00112] Examples 7 to 9 are treated into a liquid fuel at about 1500 ppm
respectively. The resultant fuel is combusted and the use of the dispersion
provides reduces by-products or pollutants from fuel combustion.
Fuel Compositions 10-12
[00113] Examples 10 to 12 are treated into a liquid fuel at about 700 ppm
respectively. The resultant fuel is combusted and the use of the dispersion
provides reduces by-products or pollutants from fuel combustion.
Fuel Compositions 13-15
[00114] Examples 13 to 15 are treated into a liquid fuel at about 1750 ppm
respectively. The resultant fuel is combusted and the use of the dispersion
provides reduces by-products or pollutants from fuel combustion.
[00115] While the invention has been explained in relation to its preferred
embodiments, it is to be understood that various modifications thereof will
become apparent to those skilled in the art upon reading the specification.
Therefore, the scope of the appended claims should not be limited by the
specific embodiments set forth herein, but should be given the broadest
interpretation consistent with the description as a whole.
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