TECHNICAL FIELD
[0001] The present disclosure relates to the field of fuels and fuel compositions, specifically
liquid fuel compositions having environmentally-friendly characteristics.
BACKGROUND
[0002] As concern for the environment grows worldwide, the safety of the various chemical
substances used in fuel compositions and fuel additive concentrates is becoming more
of a concern for manufacturers and distributors. It is paramount for the industry
to examine the use of functional fuel additive components that are also compatible
with environmental regulations. In particular, substances that are persistent in the
environment, bioaccumulative, and toxic may be banned from use Hence, there exists
a need for fuel additive compositions and fuel formulations containing such additive
compositions that incorporate more environmentally acceptable materials.
SUMWARY
[0003] In an embodiment described herein, an environmentally compatible fuel additive composition
may comprise four or more functional components, wherein each component is selected
from the group consisting of a non-persistent material, a non-bioaccumulative material,
and a non-toxic material, and wherein the additive composition is devoid of components
that are persistent, bioaccumulative, and toxic.
[0004] In another embodiment, an environmentally compatible fuel composition, may comprise
a) a major amount of a fuel; and b) a minor amount of an additive composition, comprising
four or more functional components, wherein each component comprises at least one
of: an acceptable level of biodegradation as determined by a biodegradation test,
a bioconcentration factor below 2000, or is devoid of a toxic effect at an aqueous
concentration below 0.01 mg/L on a toxicity test.
[0005] In another embodiment, a method of making an environmentally compatible fuel composition,
comprising combining a major amount of a fuel and a minor amount of an additive composition,
comprising four or more functional components, wherein each component is selected
from: a material having an acceptable level of biodegradation, a material having a
bioconcentration factor below 2000, and a material that is devoid of a toxic effect
at an aqueous concentration below 0.01 mg/L on a toxicity test, wherein the fuel composition
complies with European Council Directive 67/548/EEC.
[0006] In another embodiment, an environmentally compatible fuel composition may comprise:
a) a major amount of a fuel; and b) a minor amount of an additive composition, comprising
four or more functional components, wherein each component is selected from the group
consisting of non-persistent materials, non-bioaccumulative materials and non-toxic
materials, and wherein the additive composition is devoid of components that are persistent,
bioaccumulative, and toxic.
[0007] An advantage of embodiments of the disclosure is that an impact on the environment
by the use of materials disclosed herein is perceived to be lessened. A further advantage
is that accidental or inadvertent spills of the compositions and fuels may not pose
long term threats to humans and wildlife. Still further advantages of the compositions
and methods described herein may be acceptable to national and state regulatory agencies.
[0008] As used herein, the terms "fuel oil composition," "fuel composition," "fully formulated
fuel composition," and "fuel" are considered synonymous, fully interchangeable terminology
referring to the finished fuel product comprising a major amount of a fuel or base
oil (carrier fluid) plus a minor amount of a fuel additive composition. "Fuel" herein
can in one embodiment be selected from the group consisting of one or more of gasoline,
diesel fuel, middle distillate fuel, biodiesel fuel, an alcohol, such as but not limited
to an ethanol, bioethanol, a biobutanol, an aviation fuel, jet fuel, marine fuel,
bunker fuel, burner fuel, home heating oil (for example, home heating oil no. 6),
a gas-to-liquid (GTL) base oil, a Group I base oil, a Group II base oil, a Group III
base oil, a Group IV base oil, an ester, a vegetable oil, and mixtures thereof.
[0009] As used herein, the terms "additive package," "additive concentrate," and "additive
composition" are considered synonymous, fully interchangeable terminology referring
to the portion of the fuel composition excluding the major amount of fuel or base
oil stock mixture (carrier fluid).
[0010] As used herein, a "functional" component means a component that is used in a fuel
formulation to provide a measurable change in a characteristic or property of a fuel
containing the component or in a property of the system delivering the fuel, or the
system combusting the fuel, or the system exhausting the products from the combustion
of the fuel.
[0011] As used herein, the terms "agent" and "additive" are considered synonymous, fully
interchangeable terminology referring to any single component of a fuel composition
excluding the major amount of fuel in the mixture.
[0012] Additional objects and advantages of the disclosure will be set forth in part in
the description which follows, and/or can be learned by practice of the disclosure.
The objects and advantages of the disclosure will be realized and attained by means
of the elements and combinations particularly pointed out in the appended claims.
[0013] It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory only and are not restrictive of
the disclosure, as claimed.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0014] Exemplary embodiments of the disclosure will now be provided to illustrate limited
aspects of the preferred embodiments thereof, including various examples and illustrations
of the formulation and use of the disclosed embodiments. It will be understood that
these embodiments are presented solely for the purpose of illustrating the embodiments
and shall not be considered as a limitation upon the scope thereof.
[0015] European Council Directive 76/548/EEC, incorporated herein by reference, provides
regulatory guidance for the registration and evaluation of chemical substances that
may be exposed to the environment during the normal course of use. Guidelines and
testing procedures are enumerated therein, so that the potential environmental impact
of any substance may be quantified.
[0016] A number of diagnostic tests have been developed to measure the effects of certain
chemical substances upon various aspects of the environment. In particular, three
main parameters are used to classify such substances: namely, persistence, bioaccumulation,
and toxicity.
PERSISTENCE
[0017] The persistence of a substance in the environment may be inversely related to the
biodegradability of the substance. Biodegradability is the ability of microbes occurring
in an environment to break down a substance into simpler substances. The persistence,
or biodegradability, criterion is defined in European Council Directive 76/548/EEC
Annex XIII section 1.1, which is herein incorporated by reference, as a substance
fulfilling one of the following criteria: having a half-life in marine water longer
than 60 days, having a half-life in fresh or estuarine water longer than 40 days,
having a half-life in marine sediment longer than 180 days, having a half-life in
fresh or estuarine water sediment longer than 120 days, or having a half-life in soil
longer than 120 days.
[0018] A material's persistence in the environment may be determined by a number of different
test procedures, including the following tests: a dissolved organic carbon (DOC) die-away
test, a modified OECD screening dissolved organic carbon die-away test, a carbon dioxide
evolution test, a manometric respirometry test, a closed bottle test, a MITI test,
a Zahn-Wellens test, an activated sludge simulation test, an activated sludge respiration
inhibition test, and a modified SCAS test. The above test procedures are set forth
in European Council Directive 76/548/EEC Annex V, sections C.4, C.9, C.10, C.11, and
C.12, which are incorporated in full herein by reference, and are summarized below.
[0019] Six test methods are described that permit the screening of chemicals for ready biodegradability
in an aerobic aqueous medium:
- (a) Dissolved Organic Carbon (DOC) Die-Away (Method C.4-A)
- (b) Modified OECD Screening- DOC Die-Away (Method C.4-B)
- (c) Carbon dioxide (CO2) Evolution (Method C.4-C)
- (d) Manometric Respirometry (Method C.4-D)
- (e) Closed Bottle (Method C.4-E)
- (f) MITI (Ministry of International Trade and Industry - Japan) (Method C.4-F)
[0020] For example, a solution, or suspension, of the test substance in a mineral medium
is introduced into an inoculum and incubated under aerobic conditions in the dark
or in diffuse light. The amount of dissolved organic carbon (DOC) in the test solution
due to microbial inoculum should be kept as low as possible compared to the amount
of DOC due to the test substance. Allowance is made for the endogenous activity of
the inoculum by running parallel blank tests with inoculum but without test substance,
although the endogenous activity of cells in the presence of the substance will not
exactly match that in the endogenous control. A reference substance is run in parallel
to check the operation of the procedures.
[0021] In general, degradation is followed by the determination of parameters, such as DOC,
CO
2 production, and oxygen uptake, and measurements are taken at sufficiently frequent
intervals to allow the identification of the beginning and end of biodegradation.
With automatic respirometers the measurement is continuous. DOC is sometimes measured
in addition to another parameter but this is usually done only at the beginning and
the end of the test. Specific chemical analysis may also be used to assess primary
degradation of the test substance, and to determine the concentration of any intermediate
substances formed (obligatory in the MITI test).
[0022] Normally, the tests last for 28 days. Tests however may be ended before 28 days,
i.e., as soon as the biodegradation curve has reached a plateau for at least 3 determinations.
Tests may also be prolonged beyond 28 days when the curve shows that biodegradation
has started but that the plateau has not been reached by day 28.
[0023] The inoculum may be derived from a variety of sources: activated sludge, unchlorinated
sewage effluents, surface waters and soils, or from a mixture of these.
Dissolved Organic Carbon Die-Away Test and Modified OECD Screening Dissolved Organic
Carbon Die-Away Test
[0024] In the dissolved organic carbon die-away test and the modified OECD screening dissolved
organic carbon die-away test, a measured volume of inoculated mineral medium containing
a known concentration of the test substance (10-40 mg DOC/l) as the nominal sole source
of organic carbon is aerated in the dark or diffused light at 22 ± 2 °C. Degradation
is followed by DOC analysis at frequent intervals over a 28-day period. The degree
of biodegradation is calculated by expressing the concentration of DOC removed (corrected
for that in the blank inoculum control) as a percentage of the concentration initially
present. The degree of primary biodegradation may also be calculated from supplemental
chemical analysis made at the beginning and end of incubation.
Carbon Dioxide Evolution Test
[0025] In the carbon dioxide evolution test a measured volume of inoculated mineral medium
containing a known concentration of the test chemical (10-20 mg DOC or total organic
carbon (TOC) per liter) as the nominal sole source of organic carbon is aerated by
the passage of carbon dioxide-free air at a controlled rate in the dark or in diffuse
light. Degradation is followed over 28 days by determining the carbon dioxide produced,
which is trapped in barium or sodium hydroxide and which is measured by titration
of the residual hydroxide or as inorganic carbon. The amount of carbon dioxide produced
from the test chemical (corrected for that derived from the blank inoculum) is expressed
as a percentage of theoretical maximum carbon dioxide produced (ThCO
2). The degree of biodegradation may also be calculated from supplemental DOC analysis
made at the beginning and end of incubation.
[0026] The percentage degradation may be calculated by:

Manometric Respirometry Test
[0027] In the manometric respirometry test a measured volume of inoculated mineral medium,
containing a known concentration of test chemical (100 mg/liter of the test substance,
to give at least 50-100 mg theoretical oxygen demand/titer) as the nominal sole source
of organic carbon, is stirred in a closed flask at a constant temperature (± 1° C
or closer) for up to 28 days. The consumption of oxygen may be determined either by
measuring the quantity of oxygen (produced electrolytically) required to maintain
constant gas volume in the respirometer flask, or from the change in volume or pressure
(or a combination of the two) in the apparatus. Evolved carbon dioxide is absorbed
in a solution of potassium hydroxide or another suitable absorbent. The amount of
oxygen taken up by the test chemical (corrected for uptake by a blank inoculum, run
in parallel) is expressed as a percentage of THOD (theoretical oxygen demand) or COD
(chemical oxygen demand). Optionally, primary biodegradation may also be calculated
from supplemental specific analysis made at the beginning and end of incubation, and
ultimate biodegradation by DOC analysis.
Closed Bottle Test
[0028] In the closed bottle test a solution of the test chemical in mineral medium, usually
at 2-5 mg/liter, is inoculated with a relatively small number of micro-organisms from
a mixed population and kept in completely full closed bottles in the dark at constant
temperature. Degradation is followed by analysis of dissolved oxygen over a 28-day
period. The amount of oxygen taken up by the test chemical, corrected for uptake by
a blank inoculum run in parallel as a control, is expressed as a percentage of THOD
or COD.
MITI Test
[0029] In the MITI test, the oxygen uptake by a stirred solution, or suspension, of the
test chemical in a mineral medium, inoculated with specially grown, unadapted micro-organisms,
is measured automatically over a period of 28 days in a darkened, enclosed respirometer
at 25 ± 1 °C. Evolved carbon dioxide is absorbed by soda lime. Biodegradability is
expressed as the percentage oxygen uptake (corrected for blank uptake) of the theoretical
oxygen uptake (ThOD). The percentage of primary biodegradability is also calculated
from supplemental specific chemical analysis made at the beginning and end of incubation
and, optionally, by DOC analysis.
Zahn-Wellens Test
[0030] The purpose of the Zahn-Wellens Test is the evaluation of the potential ultimate
biodegradability of water-soluble, non-volatile organic substances when exposed to
relatively high concentrations of micro-organisms in a static test. The substances
to be studied are used in concentrations corresponding to DOC-values in the range
of 50 to 400 mg/liter or COD-values in the range of 100 to 1000 mg/liter (DOC = dissolved
organic carbon; COD = chemical oxygen demand). These relatively high concentrations
have the advantage of analytical reliability. Compounds with toxic properties may
delay or inhibit the degradation process. In this method, the measure of the concentration
of dissolved organic carbon or the chemical oxygen demand is used to assess the ultimate
biodegradability of the test substance. A simultaneous use of a specific analytical
method may allow the assessment of the primary biodegradation of the substance (disappearance
of the parent chemical structure). The method is applicable only to those organic
test substances which, at the concentration used in the test are soluble in water
under the test conditions, have negligible vapor pressure under the test conditions,
are not inhibitory to bacteria, are adsorbed within the test system only to a limited
extent, and are not lost by foaming from the test solution.
[0031] Activated sludge, mineral nutrients and the test material as the sole carbon source
in an aqueous solution are placed together in a one to four liter glass vessel equipped
with an agitator and an aerator. The mixture is agitated and aerated at 20 to 25 °C
under diffuse illumination or in a dark room for up to 28 days. The degradation process
is monitored by determination of the DOC (or COD) values in the filtered solution
at daily or other appropriate regular time intervals. The ratio of eliminated DOC
(or COD) after each interval to the value three hours after the start is expressed
as percentage biodegradation and serves as the measure of the extent of degradation
at this time. The result is plotted versus time to give the biodegradation curve.
Activated Sludge Simulation Test
[0032] The activated sludge simulation test is used to determine the primary biodegradability
of a substance in an activated sludge plant model, at a concentration of about 20
mg/liter. This allows the assessment of the primary biodegradability of the substance
(disappearance of the parent chemical structure). Another purpose of the method is
the determination of ultimate biodegradability by the measurement of the removal of
the substance and any metabolites in an activated sludge plant model at a concentration
corresponding to > 12 mg DOC/liter (or approximately 40 mg COD/liter); wherein 20
mg DOC/liter seems to be optimal.
[0033] For the determination of ultimate biodegradability, two activated sludge pilot units
are run in parallel. The test substance is added to the influent (synthetic or domestic
sewage) of one of the units, while the other blank unit receives the sewage alone.
For the determination of primary biodegradation with specific analysis in the influent
and effluent, only one unit may be used.
[0034] The sludge growth/stabilization period is the period during which the concentration
of the activated sludge suspended solids and the performance of the units' progress
to a steady state under the operating conditions used.
[0035] The running-in period is the period which lasts from the time the test substance
is first added to the time when its removal reaches a plateau (relatively constant
value). This period must not exceed six weeks.
[0036] The evaluation period is a three week period, i.e., three weeks from the time that
the removal of the test substance reaches a relatively constant, and usually high,
value. For those substances which show little or no degradation in the first six weeks,
the evaluation period is taken as the following three weeks.
[0037] Influent without substance to be tested must pass through an aeration vessel either
at the rate of one liter per hour or a rate of one-half liter per hour thereby providing
a mean retention time of either three or six hours. The rate of aeration should be
regulated so that the content of the vessel is kept constantly in suspension while
the dissolved oxygen content is at least 2 mg/liter.
[0038] The sludge which has accumulated around the top of the aeration vessel must be returned
to the mixed liquor at least once each day by brushing or some other appropriate means.
[0039] The effluent is collected in a second vessel for 20 to 24 hours, and a sample is
taken after thorough mixing.
[0040] In order to monitor and control the efficiency of the process, the chemical oxygen
demand (COD) or the dissolved organic carbon (DOC) of the filtrate of the accumulated
effluent is measured at least twice weekly, as well as that of the filtered influent
(using a membrane of pore size 0.45 µm, wherein the first 20 ml (approximately) of
the filtrate are discarded). The reduction in COD or DOC should level off when a roughly
regular daily degradation is obtained.
[0041] The operating conditions of the running-in period are maintained and sufficient stock
solution (approximately 1%) of the test material is added to the influent of the test
unit so that the desired concentration of test material (approximately 10 to 20 mg
DOC/liter or 40 mg COD/liter) in the sewage is obtained. This may be done by mixing
the stock solution to the sewage daily or by means of a separate pumping system. This
concentration may be reached progressively. If there are no toxic effects of the test
substance on the activated sludge, higher concentrations may also be tested.
[0042] The blank unit is fed only with influent without added substances. Adequate volumes
of the effluents are taken for analysis and filtered through membrane filters (0.45
µm), the first 20 ml (approximately) of filtrate being discarded.
[0043] The filtered samples have to be analyzed on the same day, otherwise they must be
preserved by any suitable method, for example, by using 0.05 ml of a 1% mercuric chloride
(HgCl
2) solution for each 10 ml of filtrate or by storing them at 2 to 4 °C up to 24 hours,
or below -18 °C for longer periods.
[0044] The running-in time, with addition of test substance, should not exceed six weeks
and the evaluation period should not be shorter than three weeks, so that about 14
to 20 determinations are available for calculation of the final result.
Activated Sludge Respiration Inhibition Test
[0045] The activated sludge respiration inhibition test assesses the effect of a test substance
on micro-organisms by measuring the respiration rate under defined conditions in the
presence of different concentrations of the test substance. The purpose of this method
is to provide a rapid screening method whereby substances which may adversely affect
aerobic microbial treatment may be identified, and to indicate suitable non-inhibitory
concentrations of test substances to be used in biodegradability tests. Two controls
without the test substance are included in the test design, one at the start and the
other at the end of the test series. Each batch of activated sludge should also be
checked using a reference substance.
[0046] The activated sludge respiration inhibition method is most readily applied to substances
which, due to their water solubility and low volatility, are likely to remain in water.
For substances with limited solubility in the test media, it may not be possible to
determine the EC
50. Results based on oxygen uptake may lead to erroneous conclusions if the test substance
has the propensity to uncouple oxidative phosphorylation, It may be useful to have
the following information to perform the test: water solubility, vapor pressure, structural
formula, and the purity of the test substance.
[0047] It is recommended that 3,5-dichlorophenol, as a known inhibitor of respiration, be
used as a reference substance and tested for EC
50 on each batch of activated sludge as a means of checking that the sensitivity of
the sludge is not abnormal.
[0048] At least five concentrations, spaced by a constant factor preferably not exceeding
3.2, are used. At time '0', 16 ml of the synthetic sewage feed are made up to 300
ml with water. 200 ml of microbial inoculum are added and the total mixture (500 ml)
poured into a first vessel (first control Cl). The test vessels should be aerated
continuously so as to ensure that the dissolved O
2 does not fall below 2.5 mg/liter and that, immediately before the measurement of
the respiration rate, the O
2 concentration is about 6.5 mg/liter.
[0049] At time '15 minutes' (15 minutes is an arbitrary, but convenient, interval) the above
is repeated, except that 100 ml of the test substance stock solution are added to
the 16 ml of synthetic sewage before adding water to 300 ml and microbial inoculum
to make a volume of 500 ml. This mixture is then poured into a second vessel and aerated
as above. This process is repeated at 15-minute intervals with different volumes of
the test substance stock solution to give a series of vessels containing different
concentrations of the test substance.
[0050] Finally, a second control is prepared (C2). After three hours the pH is recorded,
and a well-mixed sample of the contents of the first vessel is poured into the measuring
apparatus and the respiration rate is measured over a period of up to 10 minutes.
This determination is repeated on the contents of each vessel at 15-minute intervals,
in such a way that the contact time in each vessel is three hours. The reference substance
may be tested on each batch of microbial inoculum in the same way.
Modified SCAS Test
[0051] The modified SCAS test is used to evaluate the potential ultimate biodegradability
of water-soluble, non-volatile organic substances when exposed to relatively high
concentrations of micro-organisms over a long time period. The viability of the microorganisms
is maintained over this period by daily addition of a settled sewage feed.
[0052] The conditions provided by the test are highly favorable to the selection and/or
adaptation of microorganisms capable of degrading the test compound, however the procedure
may also be used to produce acclimatized inocula for use in other tests.
[0053] According to the method, the measure of the concentration of dissolved organic carbon
is used to assess the ultimate biodegradability of the test substances. It is preferable
to determine DOC after acidification and purging rather than as the difference of
C
total - C
inorganic.
[0054] The method is applicable only to those organic test substances which, at the concentration
used in the test are soluble in water (at least 20 mg dissolved organic carbon/liter),
have negligible vapor pressure, are not inhibitory to bacteria, do not significantly
adsorb within the test system, and are not lost by foaming from the test solution.
The organic carbon content of the test substance must be established prior to running
the test.
[0055] Activated sludge from a sewage treatment plant is placed in a semi-continuous activated
sludge (SCAS) unit. The test compound and settled domestic sewage are added, and the
mixture is aerated for 23 hours. The aeration is then stopped, the sludge allowed
to settle, and the supernatant liquor is removed. The sludge remaining in the aeration
chamber is then mixed with a further aliquot of test compound and sewage and the cycle
is repeated.
[0056] Biodegradation is established by determining the dissolved organic carbon content
of the supernatant liquor. This value is compared with that found for the liquor obtained
from a control tube dosed with settled sewage only.
[0057] Ideally, the dissolved organic carbon in the supernatant liquors is determined daily,
although less frequent analyses may be used. Before analysis the liquors are filtered
through washed 0.45 µm membrane filters or centrifuged. Membrane filters are suitable
if it is assured that they neither release carbon nor absorb the substance in the
filtration step. The temperature of the sample must not exceed 40 °C while it is in
the centrifuge. The length of the test for compounds showing little or no biodegradation
is indeterminate, but experience suggests that this should be at least 12 weeks in
general, but not longer than 26 weeks.
BIOACCUMULATION
[0058] Bioaccumulation, or bioconcentration, is defined as the increase in concentration
of a test substance in or on an organism or specified tissues thereof relative to
the concentration of the test substance in the surrounding medium. As used herein,
the terms "bioaccumulation" and "bioconcentration" are used interchangeably to refer
to the same criteria. The bioconcentration factor ("BCF") is calculated as the concentration
of test substance in an organism (or specified tissues thereof) divided by the concentration
of the substance in the surrounding medium. Both the uptake and depuration of substances
by organisms, and the respective rates thereof, are considered in calculating bioaccumulation.
[0059] One predictive factor for bioaccumulation may be a substance's octanol-water partition
coefficient (P
OW). The Pow is a substance's solubility in n-octanol and water at equilibrium. The
logarithm of P
OW may be an indication of a substance's potential for bioaccumulation in aquatic organisms.
[0060] The criterion for acceptable bioaccumulation is defined in European Council Directive
76/548/EEC Annex XIII section 1.2, which is herein incorporated by reference, as a
substance having a bioconcentration factor less than 2000. The bioconcentration factor
of a material may be determined by test procedures set forth in European Council Directive
76/548/EEC Annex V, section C. 13 flow-through fish test, which is incorporated in
full herein by reference.
Flow-Through Fish Test
[0061] The flow-through fish test consists of two phases: the exposure (uptake) phase and
the post-exposure (depuration) phase. During the uptake phase, separate groups of
fish of one species are exposed to at least two concentrations of the test substance.
They are then transferred to a medium free of the test substance for the depuration
phase. A depuration phase is always necessary unless uptake of the substance during
the uptake phase has been insignificant (e.g., the BCF is less than 10). The concentration
of the test substance in/on the fish (or specified tissue thereof) is followed through
both phases of the test. In addition to the two test concentrations, a control group
of fish is held under identical conditions except for the absence of the test substance,
to relate possible adverse effects observed in the bioconcentration test to a matching
control group and to obtain background concentrations of test substance.
[0062] The uptake phase is run for 28 days unless it is demonstrated that equilibrium has
been reached earlier. The depuration period is then begun by transferring the fish
to the same medium but without the test substance in another clean vessel. Where possible
the bioconcentration factor is calculated preferably both as the ratio (BCF
SS) of concentration of the fish (C
f) and in the water (C
w) at apparent steady-state and as a kinetic bioconcentration factor, BCF
K as the ratio of the rate constants of uptake (k
1) and depuration (k
2) assuming first-order kinetics.
[0063] If a steady-state is not achieved within 28 days, the uptake phase should be extended
until steady-state is reached, or 60 days, whichever comes first; the depuration phase
is then begun.
[0064] The BCF is expressed as a function of the total wet weight of the fish. However,
for special purposes, specified tissues or organs (e.g. muscle, liver), may be used
if the fish are sufficiently large or the fish may be divided into edible (fillet)
and non-edible (viscera) fractions. Since, for many organic substances, there is a
clear relationship between the potential for bioconcentration and lipophilicity, there
is also a corresponding relationship between the lipid content of the test fish and
the observed bioconcentration of such substances. Thus, to reduce this source of variability
in test results for those substances with high lipophilicity (i.e. with log P
OW>3), bioconcentration should be expressed in relation to lipid content in addition
to whole body weight.
[0065] The lipid content is determined on the same biological material as is used to determine
the concentration of the test substance, when feasible.
TOXICITY
[0066] The toxicity criterion is defined in European Council Directive 76/548/EEC Annex
XIII section 1.3, which is herein incorporated by reference, as a substance having
a long-term no-observed effect concentration (NOEC) for marine or freshwater organisms
less than 0.01mg/L. Substances that are classified as carcinogenic, mutagenic, or
toxic for reproduction may also be considered as toxic.
[0067] The toxicity of a material may be determined by test procedures, such as the acute
toxicity for fish test, the acute toxicity for
Daphnia test, and the algal inhibition test, set forth in European Council Directive 76/548/EEC
Annex V, sections C.1, C.2, and C.3, which are incorporated in full herein by reference.
These acute tests may be used for first cut screening (if LC50<1ppm), however chronic
toxicity tests (usually in Daphnia but also other organisms) may be used for definitive
Toxicity.
Acute Toxicity For Fish Test
[0068] The purpose of the acute toxicity for fish test is to determine the acute lethal
toxicity of a substance to fish in fresh water. It is desirable to have, as far as
possible, information on the water solubility, vapor pressure, chemical stability,
dissociation constants, and biodegradability of the substance to help in the selection
of the most appropriate test method (static, semi-static, or flow-through) for ensuring
satisfactorily constant concentrations of the test substance over the period of the
test.
[0069] Additional information (for instance structural formula, degree of purity, nature
and percentage of significant impurities, presence and amounts of additives, and n-octanol/water
partition coefficient) should be taken into consideration in both the planning of
the test and interpretation of the results.
[0070] Acute toxicity is the discernible adverse effect induced in an organism within a
short time (days) of exposure to a substance. In the present test, acute toxicity
is expressed as the median lethal concentration (LC
50), the concentration in water which kills 50% of a test batch of fish within a continuous
period of exposure which must be stated.
[0071] Three types of procedure may be used. The static test is a toxicity test in which
no flow of test solution occurs. The solutions remain unchanged throughout the duration
of the test. The semi-static test is a test without flow of test solution, but with
regular batchwise renewal of test solutions after prolonged periods (e.g. 24 hours).
The flow-through test is a toxicity test in which the water is renewed constantly
in the test chambers, the chemical under test being transported with the water used
to renew the test medium.
[0072] At least 7 fish per concentration being tested are exposed to the substance for a
duration of 96 hours in tanks of suitable capacity. At least five concentrations differing
by a constant factor not exceeding 2.2, and as far as possible spanning the range
of 0 to 100 % mortality, should be tested for each substance. The fish may not be
fed during the test. The fish are inspected after the first 2 to 4 hours and afterward
at least at 24-hour intervals. Fish are considered dead if touching of the caudal
peduncle produces no reaction, and no breathing movements are visible. Dead fish are
removed when observed and mortalities are recorded. Records are kept of visible abnormalities
(e.g. loss of equilibrium, changes in swimming behavior, respiratory function, pigmentation,
etc.). Measurements of pH, dissolved oxygen and temperature must be carried out daily.
Acute Toxicity For Daphnia Test
[0073] The acute toxicity for
Daphnia test is similar to the acute toxicity for fish test, but the purpose is to determine
the median effective concentration for immobilization (EC
50) of a substance to
Daphnia in fresh water. As with the toxicity for fish test, it is desirable to have, as far
as possible, information on the water solubility, vapor pressure, chemical stability,
dissociation constants, and biodegradability of the test substance before starting
the test. Additional information (for instance structural formula, degree of purity,
nature and percentage of significant impurities, presence and amount of additives,
and n-octanol/water partition coefficient) should be taken into consideration in both
the planning of the test and interpretation of the results.
[0074] The
Daphnia are exposed to the test substance added to water at a range of concentrations for
48 hours. Under otherwise identical test conditions, and an adequate range of test
substance concentrations, different concentrations of a test substance exert different
average degrees of effect on the swimming ability of
Daphnia. Different concentrations result in different percentages of
Daphnia being no longer capable of swimming at the end of the test. The concentrations causing
zero or 100% immobilization are derived directly from the test observations whereas
the 48-hour EC
50 may be determined by calculation if possible. A static system is used for this method,
hence test solutions are not renewed during the exposure period.
[0075] Stock solutions of the required strength are prepared by dissolving the substance
in deionized water or water. The chosen test concentrations are prepared by dilution
of the stock solution. If high concentrations are tested, the substance may be dissolved
in the dilution water directly.
[0076] The substances are normally only tested up to the limit of solubility. For some substances
(e. g. substances having low solubility in water, or high P
OW, or those forming stable dispersion rather than true solution in water), it is acceptable
to run a test concentration above the solubility limit of the substance to ensure
that the maximum soluble/stable concentration has been obtained. It is important,
however, that this concentration will not otherwise disturb the test system (e. g.
film of the substance on the water surface preventing the oxygenation of the water,
etc.).
[0077] Daphnia magna is the preferred test species although
Daphnia pulex is also permitted. The test animals shall be less than 24 hours old at the beginning
of the test, laboratory bred, free from overt disease, and with a known history (e.g.
breeding, any pretreatments, etc.).
[0078] The
Daphnia are exposed to the substance for 48 hours. At least 20 animals at each test concentration,
preferably divided into four batches of five animals each or two batches of 10, are
required. At least 2 ml of test solutions should be provided for each animal. The
test solution should be prepared immediately before introduction of the
Daphnia, preferably without using any solvent other than water. The concentrations are made
up in a geometric series, at a concentration ratio not exceeding 2.2. Concentrations
sufficient to give 0 and 100% immobilization after 48 hours and a range of intermediate
degrees of immobilizations permitting calculation of the 48 hour EC50 should be tested
together with controls. The test temperature should be between 18 and 22 °C, but for
each single test it should be constant within ± 1 °C. The test solutions must not
be bubble-aerated, and the animals may not be fed during the test. The pH and the
oxygen concentration of the controls and of all the test concentrations should be
measured at the end of the test; the pH of the test solutions should not be modified.
Volatile compounds should be tested in completely filled closed containers, large
enough to prevent lack of oxygen. The
Daphnia are inspected at least after 24 hours exposure and again after 48 hours.
[0079] For each period where observations were recorded (24 and 48 h), the percentage mortality
is plotted against concentration on logarithmic-probability paper. In those cases
where the slope of the concentration/percentage response curve is too steep to permit
calculation of the EC
50, a graphical estimate of this value is sufficient. When two immediately consecutive
concentrations at a ratio of 2.2 give only 0 and 100% immobilization these two values
are sufficient to indicate the range within which the EC
50 falls.
Algal Inhibition Test
[0080] The algal inhibition test may be used to determine the effects of a substance on
the growth of a unicellular green algal species. Relatively brief (72 hours) tests
may assess effects over several generations. This method may be adapted for use with
several different unicellular algal species. The method is most easily applied to
water-soluble substances which, under the conditions of the test, are likely to remain
in the water.
[0081] Exponentially-growing cultures of selected green algae are exposed to various concentrations
of the test substance over several generations under defined conditions. The test
solutions are incubated for a period of 72 hours, during which the cell density in
each solution is measured at least every 24 hours. The inhibition of growth in relation
to a control culture is determined.
[0082] Test cultures containing the desired concentrations of test substance and the desired
quantity of algal inoculum are prepared by adding aliquots of stock solutions of the
test substance to suitable amounts of pre-prepared algal cultures.
[0083] The culture flasks are shaken and placed in the culturing apparatus. The algal cells
are kept in suspension by shaking, stirring, or bubbling with air, in order to improve
gas exchange and reduce pH variation in the test solutions. The cultures are maintained
at a temperature in the range of 21 to 25 °C, controlled at ± 2 °C.
[0084] The cell density in each flask is determined at least at 24, 48 and 72 hours after
the start of the test. Filtered algal medium containing the appropriate concentration
of the test chemical is used to determine the background when using cell density measurements
other than direct counting methods.
[0085] A suitable fuel or fuel additive composition, according to one embodiment of the
present disclosure, may use functional components that may not exhibit persistence,
bioaccumulation, or toxicity when tested according to the procedures set forth above.
Accordingly, a functional component that is found to be persistent, bioaccumulative,
and toxic may not be included in fuel formulations of the present disclosure.
[0086] Acceptable functional components may include one or more components functionally
described as: an antifoam agent, an anti-icing additive, an antiknock additive, an
antioxidant, an antistatic additive, an anti-valve-seat recession additive, an antiwear
agent, a biocide, a carrier fluid, a cetane improver, a combustion improver, a compatibilizer,
a conductivity improver, a corrosion inhibitor, a dehazer, a demulsifier, a detergent,
a dispersant, a drag reducing agent, a dye, an emulsifier, a foam inhibitor, a friction
modifier, a fuel stabilizer, an injector deposit control additive, a lubricity additive,
a marker or customer-specific "tag", a metal deactivator, an octane improver, a pour
point depressant, a reodorant, a seal swell additive, a surfactant, and a wax anti-settling
additive (a "WASA"). Such components may be deemed acceptable for use in compositions
of the present disclosure upon receiving a passing evaluation in testing for persistence,
bioaccumulation, and/or toxicity using the test methods and/or criteria described
above.
[0087] Suitable embodiments of the present disclosure may incorporate one or more of the
following substances: a succinimide, an alkenyl succinimide, a polyisobutylene, a
silicon antifoamant, a dibutyl hydrogen phosphite, base oils, an organic acid, an
organic solvent, a 2-ethylhexyl nitrate, a polymer having a molecular weight of about
1000 or more, a monoalkyl thiadiazole, a dialkyl thiadiazole, an organo molybdenum
compound, and the like.
[0088] Other suitable embodiments of the present disclosure may incorporate one or more
of the following substances: a zinc dialkyl dithiophosphate, a phenate, and a sulfonate.
[0089] Other embodiments may incorporate one or more of the following substances:
Amines, polyethylenepoly-
Amines, N-(C14-18 and C16-18-unsatd. alkyl)trimethylenedi-1-Propanamine, 3-(Isodecyloxy)-C13
H29NO
Amines, coco alkyl
Dibenz(a,h)anthracene
Isooctane
Amines, coco alkyldimethyl
Amines, tallow alkyl, ethoxylated
Amines, n-tallow alkyltrimethylenedi
Amines, C14-18 and C16-18-unsaturated alkyl
Triphenyl phosphite
Amines, dicoco alkylmethyl
Glycine n-methyl-n-(1-oxo-9-octadecenyl)
Alcohols, C12-14, ethoxylate
Amines, C 16-22-tert-alkyl
Polysulfides, di-tert-butyl-
Alcohols, C 12-16 ethoxylated
Alkylphenol polyoxyalkyl alkylamine (in FDE-1)
1-Hexadecanamine
N,N-dimethyl-1-octadecanamine
N alkyl (coco) diethanolamine
1,3-Propanediamine, n-9-Octadecenyl-, (z)-
Phenol, nonyl-
9-Octadece-1-amine, (Z)-
Phenyl-alpha-naphthalene
2,6-DTBP
S-Alkenyl-O,O-dialkyldithiophosphates
[0090] Suitable embodiments may comprise one or more of polyetheramine and/or at least one
agent selected from the group consisting of succinimide dispersants, succinamide dispersants,
amides, Mannich base dispersants, p-phenylenediamine, dicyclohexylamine, phenolics,
hindered phenolics, aryl amines, diphenyl amines, monocarboxylic acids, dicarboxylic
acids, polycarboxylic acids, methyl cyclopentadienyl manganese tricarbonyl, cyclopentadienyl
manganese tricarbonyl, azides, peroxides, alkyl nitrates, oxylated alkylphenolic resins,
formaldehyde polymer with 4-(1,1-dimethylethyl)phenol, methyloxirane and oxirane,
octane enhancer materials, monoesters, diesters, ethers, diethers, methyloxirane,
oxiranes, peroxides, alkyl nitrates, C1-C8 aliphatic hydrocarbons, ketones, butylene
oxides, propylene oxides, ethylene oxides, epoxides, butane, pentane, nitrous oxide,
nitromethane, xylene, diethyl ether, polyethers, glycols, phenates, salicylates, sulfonates,
nonylphenol ethoxylates, alkali detergents and alkaline earth metal-containing detergents,
tall oil fatty acids, dodecenyl succinic acid, and oleic acid plus N,N dimethylcyclohexylamine,
2,6-di t-butyl phenol, methylcyclopentadienyl manganese tricarbonyl, oleic acid plus
N,N dimethylcyclohexylamine, dodecenyl succinic acid, polyisobutylene amine dispersant,
1,2 propane diamine salicylaldehyde, cresol Mannich base dispersant, diethanol amide
of isostearic acid, and 2-ethyl hexyl nitrate.
[0091] An exemplary fuel composition containing functional components, wherein each component
is selected from non-persistent, non-bioaccumulative, and non-toxic materials is illustrated
in the following table.
Table 1-Conventional Fuel Additives
| Component |
Example 1 (mass % based on finished fuel) |
Example 2 (mass % based on finished fuel) |
| Dispersant |
0 - 60 |
10 - 55 |
| Demulsifier |
0 - 15 |
0.1 - 5 |
| Compatibilizer |
0 - 10.0 |
0.01 - 5.0 |
| |
0 - 5.0 |
0 - 2.0 |
| Combustion improver |
|
|
| Antifoaming agent |
0-5.0 |
0,001 - 0,15 |
| Pour point depressant |
0 - 5.0 |
0.01 - 1.5 |
| Friction modifier |
0 - 1.25 |
0.05 - 1.0 |
| Seal swell agent |
0 - 15 |
1.5 - 10 |
| Carrier Fluid/Solvent |
0 - 30.0 |
0.1 - 25.0 |
| Fuel |
Balance |
Balance |
[0092] The conventional additives indicated in Table I may be combined with one or more
fuels and/or one or more base oils. Suitable fuels may comprise any known hydrocarbon
fuel or mixtures thereof. Suitable fuels may include one or more of gasoline, diesel
fuel, middle distillate fuel, biodiesel fuel, an alcohol, such as but not limited
to an ethanol, bioethanol, a biobutanol, an aviation fuel, jet fuel, marine fuel,
bunker fuel, burner fuel, home heating oil (for example, home heating oil no. 6),
a gas-to-liquid (GTL) base oil, a Group I base oil, a Group II base oil, a Group III
base oil, a Group IV base oil, an ester, a vegetable oil, and mixtures thereof.
Gasolines
[0093] The fuel used in the fuel composition embodiments of the present disclosure may comprise
a petroleum hydrocarbon useful as a fuel, e.g., gasoline, for internal combustion
engines. Such fuels typically comprise mixtures of hydrocarbons of various types,
including straight and branched chain paraffins, olefins, aromatics, and naphthenic
hydrocarbons, and other liquid hydrocarbonaceous materials suitable for spark ignition
gasoline engines.
[0094] These compositions are provided in a number of grades, such as unleaded and leaded
gasoline, and are typically derived from petroleum crude oil by conventional refining
and blending processes such as straight run distillation, thermal cracking, hydrocracking,
catalytic cracking, and various reforming processes. Gasoline may be defined as a
mixture of liquid hydrocarbons or hydrocarbon-oxygenates having an initial boiling
point in the range of about 20 to 60 °C and a final boiling point in the range of
about 150 to 230 °C, as determined by the ASTM D86 distillation method. The gasoline
may contain other combustibles such as alcohol, for example methanol or ethanol.
[0095] The combustible fuels used in formulating the fuel compositions of the present disclosure
may include any combustible fuels suitable for use in the operation of direct injection
gasoline engines such as leaded or unleaded motor gasolines, and so-called reformulated
gasolines which typically contain both hydrocarbons of the gasoline boiling range
and fuel-soluble oxygenated blending agents ("oxygenates"), such as alcohols, ethers,
and other suitable oxygen-containing organic compounds. Preferably, the fuel is a
mixture of hydrocarbons boiling in the gasoline boiling range. This fuel may consist
of straight chain or branch chain paraffins, cycloparaffins, olefins, aromatic hydrocarbons,
or any mixture of these. The gasoline can be derived from straight run naptha, polymer
gasoline, natural gasoline, or from catalytically reformed stocks boiling in the range
from about 80 to about 450 °F. The octane level of the gasoline is not critical and
any conventional gasoline may be employed in the practice of this invention.
[0096] Oxygenates suitable for use in the present invention include methanol, ethanol, isopropanol,
t-butanol, mixed C
1 to C
5 alcohols, methyl tertiary butyl ether, tertiary amyl methyl ether, ethyl tertiary
butyl ether and mixed ethers. Oxygenates, when used, will normally be present in the
base fuel in an amount below about 30% by volume, and preferably in an amount that
provides an oxygen content in the overall fuel in the range of about 0.5 to about
5 percent by volume.
Diesel
[0097] Diesel fuel contains hydrocarbons having higher boiling points than those of gasoline.
Diesel fuel generally has a distillation range between 320 °F to 715 °F (about 160
°C. and 380 °C.). Gasoline generally distills below this temperature range, e.g.,
between about 100 °F to 400 °F (about 40 °C. and 205 °C). Diesel fuels generally contain
more sulfur and nitrogen than gasoline. Moreover, gasoline is designed to resist burning
when compressed in the absence of a spark. Such burning is undesired because it causes
knocking. Diesel fuel is the opposite. Diesel fuel must ignite spontaneously and quickly
(within 1 to 2 milliseconds) without a spark. The time lag between the initiation
of injection and the initiation of combustion is called ignition delay. In high-speed
diesel engines, a fuel with a long ignition delay tends to produce rough operation
and knocking. Two major factors affect ignition delay: a mechanical factor and a chemical
factor.
[0098] The mechanical factor is influenced by such things as compression ratio, motion of
the air charge during ignition, and ability of the fuel injector to atomize fuel.
The differences between diesel engines and gasoline engines are reflected by how their
mechanical factors are affected differently by changing the dimensions of their mechanical
parts. For example, the larger the cylinder diameter of a diesel engine, the simpler
the development of good combustion. In contrast, the smaller the cylinder of a gasoline
engine, the less the danger of premature detonation of fuel. High intake-air temperature
and density (provided by a supercharger) aid combustion in a diesel engine. In contrast,
high intake-air temperature and density (provided by a supercharger) increases the
tendency to knock, necessitating higher octane fuel, in a gasoline engine.
[0099] The chemical factor is influenced by such things as the fuel's auto ignition temperature,
specific heat, density, and other physical properties. The ability of a diesel fuel
to ignite quickly after injection into a cylinder is known as its cetane number. The
ability of a gasoline to resist burning prior to introduction of a spark is known
as its octane number. A higher cetane number is equivalent to a lower octane number.
Diesel fuels generally have a clear cetane number, i.e., a cetane number when devoid
of any cetane improver, in the range of 40 to 60.
Biodiesel
[0100] Biodiesel fuel may comprise alkyl esters made from the transesterification of vegetable
oils or animal fats. Biodiesel is biodegradable and non-toxic, and typically produces
less net carbon dioxide emissions than petroleum-based diesel. Biodiesel may be manufactured
from algae, vegetable oils, animal fats, or recycled restaurant greases. Examples
of biodiesel include rapeseed methyl ester, vegetable methyl ester, and fat methyl
ester (produced from vegetable and animal products), Suitable crops that may be processed
to yield biodiesel may include corn (maize), cashew nuts, oats, lupine, kenaf, calendula,
cotton, hemp, soybeans, coffee, linseed (flax), hazelnuts, euphorbia, pumpkin seeds,
coriander, mustard seeds, camelina, sesame, safflower, rice, tung tree oil, sunflowers,
cocoa (cacao), peanuts, opium poppy, rapeseed, olives, castor beans or seeds, pecan
nuts, jojoba, jatropha, macadamia nuts, Brazil nuts, avocado, coconuts, palm oil,
Chinese tallow, Algae, and the like. Other suitable biodiesel feedstocks may comprise
waste vegetable oil such as animal fats including tallow, lard, yellow grease, chicken
fat, and the by-products of the production of Omega-3 fatty acids from fish oil. Another
source is sewage.
[0101] Chemically, transesterified biodiesel comprises a mix of mono-alkyl esters of long
chain fatty acids. Typically, methanol is used to produce methyl esters, although
ethanol can be used to produce an ethyl ester biodiesel and higher alcohols such as
isopropanol and butanol. A lipid transesterification production process may be used
to convert the base oil to the desired esters. Any Free fatty acids (FFAs) in the
base oil may be either converted to soap and removed from the process, or they may
be esterified (yielding more biodiesel) using an acidic catalyst.
[0102] A diesel fuel may comprise petroleum diesel, biodiesel or biodiesel blended with
petroleum diesel in any ratio of from 99:1 to 1:99 v/v.
Biobutanol
[0103] Biobutanol may be produced from biomass as well as fossil fuels. Butanol may be produced
by fermentation of biomass. The feedstocks are similar to those for producing ethanol;
namely, energy crops such as sugar beets, sugar cane, corn grain, wheat and cassava
as well as agricultural byproducts such as straw and corn stalks.
Ethanol
[0104] Suitable fuels may comprise an ethanol. Ethanol comprises ethyl alcohol, having the
chemical compound C
2H
5OH. This can arise in or be provided in many qualities or grades, such as commercial
or fuel grade, as well as pure or reagent grade ethanol, and can be derived from any
source such as but not limited to petroleum refinery streams, distillation cuts, and
bio-derived (e.g. bioethanol from corn or other crops). In some embodiments, ethanol
may be present in an amount of from about 10 to about 100 wt% based on the total fuel
composition. In another embodiment, the ethanol may be present in an amount of from
about 15 to about 85 wt% based on the total fuel composition. In an even further embodiment,
the ethanol may be present in an amount of from about 74 to about 85 wt% based on
the total fuel composition. In another embodiment herein is provided a fuel composition
that can be, or can comprise, 1.0 to 100 volume percent of one or more alcohols, and
0 to 99% gasoline.
[0105] In some embodiments, the ethanol fuel may comprise an ethanol having about 0.9 PTB
or less of a corrosion inhibitor, such as Innospec DCI-11 corrosion inhibitor. In
some embodiments, the ethanol may comprise about 32 PTB of corrosion inhibitor, such
as Innospec DCI-11 corrosion inhibitor.
[0106] Ethanol may be produced from fossil fuel feedstocks or by fermentation of sugars
derived from grains or other biomass materials. Therefore, ethanol suitable for use
in accordance with the fuel compositions described herein may be fuel grade ethanol
derived from yeast or bacterial fermentation of starch-based sugars. Such starch-based
sugars may be extracted from corn, sugarcane, tapioca, sugar beet, and the like. Alternatively,
fuel grade ethanol may be produced via known dilute and/or concentrated acid and/or
enzymatic hydrolysis of a particular biomass material for example, from waste industrial
sources including, cellulosic portions of municipal solid waste, waste paper, paper
sludge, saw dust, and the like, Biomass may also be collected from agricultural residues
including, for example, rice husks and paper-mill sludge.
[0107] A suitable fuel grade ethanol may contain none or only contaminant levels of water.
Alternatively, a suitable fuel grade ethanol may contain higher amounts of water,
up to 5% w/w (hydrous ethanol).
Fuel Oil
[0108] Suitable fuel oils may comprise any of fuel oils in class numbers 1-6, including
those otherwise mentioned herein, and mixtures thereof. Fuel oils may comprise distillates,
residuals, or mixtures thereof. Fuel oil may comprise aviation fuel, jet fuel, marine
fuel, burner fuel, bunker fuel, home heating oil, diesel fuel, turbine engine fuel,
kerosene, range oil, and the like.
Base Oils
[0109] Suitable base oils may be selected from any of the base oils in Groups I-V as specified
in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines.
Such base oil groups are as follows:
Table 2 - Base Oil Groups
| Base Oil Group 1 |
Sulfur (wt.%) |
|
Saturates (wt.%) |
Viscosity Index |
| Group I |
> 0.03 |
and/or |
<90 |
80 to 120 |
| Group II |
< 0.03 |
and |
> 90 |
80 to 120 |
| Group III |
< 0.03 |
and |
> 90 |
> 120 |
| Group IV |
all polyalphaolefins (PAOs) |
|
|
|
| Group V |
all others not included in Groups I-IV |
|
|
|
| 1Groups I-III are mineral oil base stocks. |
[0110] In addition to the above conventional base oils, the base oils may also be selected
from gas-to-liquid (GTL) base oils. GTL base oils may be made by a process, such as
the process described in
U.S. Patent No. 6,497,812, the disclosure of which is incorporated herein by reference. The GTL process includes
two primary steps, (1) conversion of a material existing in the gaseous state into
a synthesis gas consisting primarily of carbon monoxide and hydrogen, and the conversion
of the synthesis gas into a synthetic crude in a reaction based on a Fischer-Tropsch
reaction. Direct conversion of gaseous hydrocarbon sources using various catalysts
and/or catalytic systems may also be used as the GTL process.
[0111] Base oils derived from a gaseous source, hereinafter referred to as "GTL base oils,"
typically have a viscosity index of greater than about 130, a sulfur content af less
than about 0.3 percent by weight, contain greater than about 90 percent by weight
saturated hydrocarbons (isoparaffins), typically from about 95 to about 100 wt.% branched
aliphatic hydrocarbons, have a pour point of below -15 to -20°C., and have a NOACK
volatility of less than about 15 weight percent, and in another embodiment a NOACK
volatility of less than about 10 weight percent. Other characteristics of the GTL
base oil may be within the range of conventional fuel base oils. The base oil component
of the fuel composition, as described herein, may include from about 5 to about 100
percent by weight of the GTL base oil with the balance of the base oil component being
a conventional base oil. Because of the characteristically high content of branched
alkanes in the GTL base oils, finished fuel formulations made with such GTL base oils
include a solubilizing agent that aids in solubilizing additives and degradation products
in the finished fuel formulation. The GTL base oils may be used alone or may be mixed
with any one or more of the other base oils listed in Table II above.
Carrier Fluids/Diluents
[0112] In some embodiments, the additives or additive package may be used with a liquid
carrier or induction aid. Suitable carrier fluids may include any base oil as defined
herein. Further suitable carrier fluids can be of various types, such as for example
liquid poly-alpha-olefin oligomers, mineral oils, liquid poly(oxyalkylene) compounds,
liquid alcohols or polyols, polyalkenes, liquid esters, and similar liquid carriers.
Mixtures of two or more such carriers can be employed.
[0113] Liquid carriers can include butane not limited to 1) a mineral oil or a blend of
mineral oils that have a viscosity index of less than about 120, 2) one or more poly-alpha-olefin
oligomers, 3) one or more poly(oxyalkylene) compounds having an average molecular
weight in the range of about 500 to about 3000, 4) polyalkenes, 5) polyalkyl-substituted
hydroxyaromatic compounds or 6) mixtures thereof. The mineral oil carriers that can
be used include paraffinic, naphthenic, and asphaltic oils, and can be derived from
various petroleum crude oils and processed in any suitable manner. For example, the
mineral oils may be solvent extracted or hydrotreated oils. Reclaimed mineral oils
can also be used. Hydrotreated oils may also be used. The mineral oil may have a viscosity
at 40 °C of less than about 1600 SUS, and as another example, between about 300 and
1500 SUS at 40 °C. Paraffinic mineral oils may have viscosities at 40 °C in the range
of about 475 SUS to about 700 SUS. The mineral oil may have a viscosity index of less
than about 100, such as less than about 70, and further such as in the range of from
about 30 to about 60.
[0114] Suitable poly-alpha-olefins (PAO) may comprise the hydrotreated and unhydrotreated
poly-alpha-olefin oligomers, i.e., hydrogenated or unhydrogenated products, primarily
trimers, tetramers, and pentamers of alpha-olefin monomers, which monomers contain
from 6 to 12, generally 8 to 12, and in some instances about 10 carbon atoms. Their
synthesis is outlined in
Hydrocarbon Processing, February 1982, page 75 et seq., and in
U.S. Pat. Nos. 3,763,244;
3,780,128;
4,172,855;
4,218,330; and
4,950,822. The usual process essentially comprises catalytic oligomerization of short chain
linear alpha olefins (suitably obtained by catalytic treatment of ethylene). The poly-alpha-olefins
used as carriers will usually have a viscosity (measured at 100 °C) in the range of
2 to 20 centistokes (cSt). As another example, the poly-alpha-olefin has a viscosity
of at least 8 cSt, and as an even further example, about 10 cSt at 100 °C.
[0115] The poly (oxyalkylene) compounds which are among the carrier fluids for use in this
invention are fuel-soluble compounds which can be represented by the following formula
a R
1-(R
2-O)
n--R
3 wherein R
1 is typically a hydrogen, alkoxy, cycloalkoxy, hydroxy, amino, hydrocarbyl (e.g.,
alkyl, cycloalkyl, aryl, alkylaryl, aralkyl, etc.), amino-substituted hydrocarbyl,
or hydroxy-substituted hydrocarbyl group, R
2 is an alkylene group having 2-10 carbon atoms (preferably 2-4 carbon atoms), R
3 is typically a hydrogen, alkoxy, cycloalkoxy, hydroxy, amino, hydrocarbyl (e.g.,
alkyl, cycloalkyl, aryl, alkylaryl, aralkyl, etc.), amino-substituted hydrocarbyl,
or hydroxy-substituted hydrocarbyl group, and n is an integer from 1 to 500 and such
as in the range of from 3 to 120 representing the number (usually an average number)
of repeating alkyleneoxy groups. In compounds having multiple --R
2--O-- groups, R
2 can be the same or different alkylene group and where different, can be arranged
randomly or in blocks. Suitable poly (oxyalkylene) compounds are monools comprised
of repeating units formed by reacting an alcohol with one or more alkylene oxides,
preferably one alkylene oxide.
[0116] The average molecular weight of the poly (oxyalkylene) compounds used as carrier
fluids may be in the range of from about 500 to about 3000, such as from about 750
to about 2500, and further such as from above about 1000 to about 2000.
[0117] A useful sub-group of poly (oxyalkylene) compounds is comprised of the hydrocarbyl-terminated
poly(oxyalkylene) monools such as are referred to in the passage at column 6, line
20 to column 7 line 14 of
U.S. Pat. No. 4,877,416 and references cited in that passage, said passage and said references being fully
incorporated herein by reference.
[0118] A suitable sub-group of poly (oxyalkylene) compounds is comprised of one or a mixture
of alkyl poly (oxyalkylene)monools which in its undiluted state is a gasoline-soluble
liquid having a viscosity of at least about 70 centistokes (cSt) at 40 °C and at least
about 13 cSt at 100°C. Of these compounds, monools formed by propoxylation of one
or a mixture of alkanols having at least about 8 carbon atoms, and as another example
in the range of about 10 to about 18 carbon atoms, are suitable.
[0119] The poly (oxyalkylene) carriers used in the practice of this invention may have viscosities
in their undiluted state of at least about 60 cSt at 40 °C (as another example at
least about 70 cSt at 40 °C) and at least about 11 cSt at 100 °C (as another example
at least about 13 cSt at 100 °C). In addition, the poly (oxyalkylene) compounds used
in the practice of this invention may have viscosities in their undiluted state of
no more than about 400 cSt at 40 °C and no more than about 50 cSt at 100 °C. As another
example, their viscosities will not exceed about 300 cSt at 40 °C and will not exceed
about 40 cSt at 100 °C.
[0120] Suitable poly (oxyalkylene) compounds also include poly (oxyalkylene) glycol compounds
and mono ether derivatives thereof that satisfy the above viscosity requirements and
that are comprised of repeating units formed by reacting an alcohol or polyalcohol
with an alkylene oxide, such as propylene oxide and/or butylene oxide with or without
use of ethylene oxide, and especially products in which at least 80 mole % of the
oxyalkylene groups in the molecule are derived from 1,2-propylene oxide. Details concerning
preparation of such poly(oxyalkylene) compounds are referred to, for example, in
Kirk-Othmer, Encyclopedia of Chemical Technology, Third Edition, Volume 18, pages
633-645 (Copyright 1982 by John Wiley & Sons), and in references cited therein, the foregoing excerpt of the Kirk-Othmer encyclopedia
and the references cited therein being incorporated herein in total by reference.
U.S. Pat. Nos. 2,425,755;
2,425,845;
2,448,664; and
2,457,139 also describe such procedures, and are fully incorporated herein by reference.
[0121] The poly (oxyalkylene) compounds, when used, may contain a sufficient number of branched
oxyalkylene units (e.g., methyldimethyleneoxy units and/or ethyldimethyleneoxy units)
to render the poly (oxyalkylene) compound gasoline soluble.
[0122] Suitable poly (oxyalkylene) compounds for use in the present invention include those
taught in
U.S. Pat. Nos. 5,514,190;
5,634,951;
5,697,988;
5,725,612;
5,814,111 and
5,873,917, the disclosures of which are incorporated herein by reference.
[0123] Suitable polyalkenes may also include polypropene and polybutene. The polyalkenes
may have a molecular weight distribution (Mw/Mn) of less than 4. In an embodiment,
the polyalkenes may have a MWD of 1.4 or below. Suitable polybutenes have a number
average molecular weight (Mn) of from about 500 to about 2000, such as 600 to about
1000, as determined by gel permeation chromatography (GPC). Suitable polyalkenes for
use in the present invention are taught in
U.S. Pat. No. 6,048,373, which descriptions are incorporated herein by reference.
[0124] The polyalkyl-substituted hydroxyaromatic compounds suitable for use in the present
invention include those compounds known in the art as taught in
U.S. Pat. Nos. 3,849,085;
4,231,759;
4,238,628;
5,300,701;
5,755,835 and
5,873,917, the disclosures of which are incorporated herein by reference.
Anti-Icing Agents
[0125] Various compounds known for anti-icing may be utilized in the present embodiments.
For example, suitable anti-icing agents may comprise ether polymers, glycols, and
alcohols.
Antioxidants
[0126] Various compounds known for use as oxidation inhibitors can be utilized in embodiments
disclosed herein. These include phenolic antioxidants, amine antioxidants, sulfurized
phenolic compounds, aromatic amine antioxidants, and organic phosphites, among others.
The antioxidant may be composed predominantly or entirely of either (1) a hindered
phenol antioxidant such as 2-tert-butylphenol, liquid mixtures of tertiary butylated
phenols, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol,
4-methyl-2,6-di-tert-butylphenol, 4,4'-methylenebis-(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol),
mixed methylene-bridged polyalkyl phenols, 4,4'-thiobis(2-methyl-6-tert-butyl phenol),
and mixed methylene bridged polyalkyl phenols, or (2) an aromatic amine antioxidant
such as the cycloalkyl-di-lower alkyl amines, and phenylenediamines, or a combination
of one or more such phenolic antioxidants with one or more such amine antioxidants,
or N,N'-di-sec-butyl-p-phenylenediamine, 4-isopropylaminodiphenyl amine, phenyl-naphthyl
amine, phenyl-naphthyl amine, and ring-alkylated diphenylamines. Suitable antioxidants
may comprise tertiary butyl phenols, such as 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol,
o-tertbutylphenol.
Cold Flow Improvers
[0127] Suitable cold flow improvers may comprise ethylene-unsaturated ester copolymers,
comb polymers, nitrogen-containing polar compounds, hydrocarbon polymers, linear compounds,
and mixtures of any of these. Cold flow improvers which may be used are known in the
art and are commercially available from a number of sources. As used herein the term
"cold flow improver" also includes pour point depressants, wax crystal modifiers,
and wax anti-settling additives of the types usually added to middle distillate fuels
to improve low temperature properties. Such materials are known in the art and are
commercially available.
[0128] Examples of cold flow improvers include copolymers of ethylene with ethylenically
unsaturated esters, or derivatives thereof. Thus, the copolymer may be of ethylene
with an ester of a saturated alcohol and an unsaturated carboxylic acid or, for example,
the ester of an unsaturated alcohol with a saturated carboxylic acid. The use of ethylene-vinyl
ester copolymers is suitable, as further examples, ethylene-vinyl acetate, ethylene-vinyl
propionate, ethylene-vinyl hexanoate, and ethylene-vinyl octanoate copolymers are
also suitable.
[0129] The copolymers usually contains from 1 to 40 wt %, as another example from 5 to 35
wt %, as an even further example from 10 to 35 wt % vinyl ester. Mixtures of two or
more copolymers may also be used (see
U. S. Pat. No. 3,961,916).
[0130] The number average molecular weight of the copolymer, as measured by vapor phase
osmometry, is typically 1,000 to 10,000 or as another example 1,000 to 5,000. If desired,
the copolymer may contain units derived from additional comonomers, e.g. a terpolymer,
tetrapolymer, or a higher polymer, for example where the additional comonomer is isobutylene
or diisobutylene.
[0131] The copolymers may be made by direct polymerization of comonomers, by transesterification,
or by hydrolysis and re-esterifcation, of an ethylene unsaturated ester copolymer
to give a different ethylene unsaturated ester copolymer.
[0133] The hydrocarbyl groups may have from 10 to 30 carbon atoms and are bonded directly
or indirectly to the polymer backbone. Examples of indirect bonding include bonding
via interposed atoms or groups. This can include covalent and/or electrovalent bonding
such as in a salt.
[0134] The comb polymer is typically a homopolymer or a copolymer having at least 20 and
as another example at least 40, and as an even further example at least 50, mole %
of units having side branches containing at least 6, and as another example at least
10, carbon atoms. It is possible for the comb polymer to contain units derived from
other monomers.
[0135] Examples of comb polymers which may be used include homopolymers of, for example
fumaric or itaconic acid, and copolymers of maleic anhydride, fumaric acid or itaconic
acid with another ethylenically unsaturated monomer, such as an alpha-olefin, for
example 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene or an
unsaturated ester, for example, vinyl acetate. The copolymer may be esterified by
reaction with an alcohol such as n-decan-1-ol, n-dodecan-1-ol, n-tetradecan-1-ol,
n-hexadecan-1-ol, n-octadecan-1-ol, 1-methylpentadecan-1-ol, or 2-methyltridecan-1-ol.
Mixtures of alcohols may be used although it is typical to use pure alcohols rather
than the commercially available alcohol mixtures.
[0137] Suitable fumarate comb polymers are copolymers of (C
12-20 alkyl) fumarates with vinyl acetate, especially those in which the alkyl groups have
14 carbon atoms or in which the alkyl groups are a mixture of C
14 /C
16 alkyl groups. These may be made by known techniques.
[0138] Other suitable comb polymers which may be used include the polymers and copolymers
of a-olefins and esterified copolymers of styrene and maleic anhydride and esterified
copolymers of styrene and fumaric acid.
[0139] Useful comb polymers may have a number average molecular weight, as measured by vapor
phase osmometry, of 1,000 to 100,000, or as another example 1,000 to 30,000.
[0140] Polar nitrogen compounds which may be used as cold flow improvers are known in the
art and usually contain one or more of the same or different nitrogen-bound hydrocarbyl
groups, possibly in the form of a a cation.
[0141] The hydrocarbyl groups generally contain up to 40 carbon atoms. Examples of hydrocarbyl
groups include aliphatic (e.g. alkyl or alkenyl), alicyclic (e.g. cycloalkyl or cycloalkenyl),
aromatic, and alicyclic-substituted aromatic, and aromatic-substituted aliphatic and
alicyclic group Aliphatic groups typically contain 12 to 24 carbon atoms and are advantageously
saturated.
[0142] The hydrocarbyl groups may contain non-hydrocarbon substituents provided their presence
does not alter the predominantly hydrocarbon character of the group, such as keto,
halo, hydroxy, nitro, cyano, alkoxy, and acyl groups. If the hydrocarbyl group is
substituted, a single (mono) substituent is preferred. Examples of substituted hydrocarbyl
groups include 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-ketopropyl, ethoxyethyl
and propoxypropyl.
[0143] The hydrocarbyl groups may also or alternatively contain atoms other than carbon
in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms include
nitrogen, sulphur, and oxygen. The hydrocarbyl group may be bound to one or more nitrogen
atoms via an intermediate linking group such as --CO--, --CO
2 (--), --SO
3 (--) or hydrocarbylene. When the polar nitrogen compound carries more than one nitrogen-bound
substituent, the linking groups for each substituent may be the same or different.
[0144] The polar nitrogen compounds may contain amino substituents such as long chain C
12 -C
40, alkyl primary, secondary, tertiary or quaternary amino substituents. The amino substituent
may be a dialkylamino substituent which may be in the form of an amine salt thereof
(tertiary and quaternary amines can form only amine salts). The alkyl groups may be
the same or different.
[0145] Examples of primary amino substituents include dodecylamino, tetradecylamino, cocoamino,
and hydrogenated tallow amino. Examples of secondary amino substituents include dioctadecylamino
and methylbehenylamino. Mixtures of amino substituents may be present such as those
derived from naturally occurring amines. A preferred amino substituent is the secondary
hydrogenated tallow amino substituent, the alkyl groups of which are derived from
hydrogenated tallow fat. These are typically composed of approximately 4% C
14, 31% C
16 and 59% C
18 n-alkyl groups by weight.
[0146] The polar nitrogen compounds may contain imino substituents such as long chain C
12 -C
40 alkyl substituents. The substituents may be monomeric (cyclic or non-cyclic) or polymeric.
When non-cyclic, the substituent may be obtained from a cyclic precursor such as an
anhydride. The cyclic precursor may include homocyclic, heterocyclic, or fused polycyclic
assemblies, or a system where two or more identical or different such cyclic assemblies
are joined to one another. Where there are two or more such cyclic assemblies, the
substituents may be on the same or different assemblies. Each cyclic assembly may
be aromatic or may comprise a benzene ring. The cyclic ring system may comprise a
single benzene ring having substituents in the ortho- or meta-positions. The benzene
ring may be optionally further substituted. The ring atoms in the cyclic assembly
or assemblies may for example include one or more N, S or O atom.
[0147] Examples of polycyclic assemblies include: (a) condensed benzene structures such
as naphthalene, anthracene, phenanthrene, and pyrene; (b) condensed ring structures
such as azulene, indene, hydroindene, fluorine, and diphenylene oxides; (c) joined
rings such as diphenyl; (d) heterocyclic compounds such as quinoline, indole, 2,3-dihydroindole,
benzofuran, coumarin, isocoumarin, benzothiophen, carbazole, and thiodiphenylamine;
(e) partially saturated or non-aromatic ring systems such as decalin (i.e. decahydronaphthalene),
alpha.-pinene, cardinene, and bomylene; and (f) three-dimensional structures such
as norbornene, bicycloheptane (i.e. norbomane), bicyclooctane, and bicyclooctene.
[0148] Further and specific examples of polar nitrogen compounds which may be used in the
present embodiments can be found in the art for example in
U.S. Pat. No. 4,211,534,
U.S. Pat. No. 4,147,520,
U.S. Pat. No. 4,631,071,
U.S. Pat. No. 4,639,256,
DE-A-3,916,366,
EP-A-413,279,
EP-A-0,261,957,
EP-A-272,889,
EP-A-31b,108,
GB-A-2,121,807,
FR-A-2,592,387,
DE-A-941,561,
EP-A-283,292 and
EP-A-353,981.
[0150] The hydrocarbon polymers may be made directly from monoethylenically unsaturated
monomers or indirectly by hydrogenating polymers from polyunsaturated monomers, e.g.
isoprene and butadiene.
[0151] Also suitable are ethylene a-olefin copolymers having a number average molecular
weight of at least 30,000 as measured by gel permeation chromatography (GPC) relative
to polystyrene standards. Viscosity mixing difficulties may arise when the molecular
weight is above about 150,000.
[0152] The alpha-olefin may have at most 30 carbon atoms. Examples of such include propylene,
1-butene, isobutene, n-octene-1, isooctene-1, n-decene-1, and n-dodecene-1. The copolymer
may also comprise small amounts, e.g. up to 10% by weight, of other copolymerisable
monomers, for example olefins other than alpha-olefins, and non-conjugated dienes.
The preferred copolymer is an ethylene-propylene copolymer.
[0153] Usually, the copolymer has a molar ethylene content of between 50 and 85%, preferably
60 to 75%, and most preferably 65 to 70%.
[0154] The ethylene a-olefin copolymers may be ethylene-propylene copolymers with a number
average molecular weight in the range 60,000 to 120,000, such as from 80,000 to 100,000.
[0155] The hydrocarbon polymers may be prepared by any of the methods known in the art,
for example, using a Ziegler type catalyst. The polymers may be substantially amorphous,
since highly crystalline polymers are relatively insoluble in fuel oil at low temperatures.
[0156] Other suitable hydrocarbon polymers include low molecular weight ethylene-a-olefin
copolymers, typically with a number average molecular weight (by GPC) of at most 7500,
for example from 1,000 to 6,000, such as from 2,000 to 5,000, as measured by vapor
phase osmometry. Appropriate alpha-olefins are as given above. Styrene may also be
used.
[0157] Linear cold flow improver compounds typically comprise a compound in which at least
one substantially linear alkyl group having 10 to 30 carbon atoms is linked via an
optional linking group to a non-polymeric residue, such as an inorganic residue, to
provide at least one linear chain of atoms that includes the carbon atoms of the alkyl
groups and one or more non-terminal oxygen, sulphur, and/or nitrogen atoms. The linking
group may be polymeric. Polyoxyalkylene compounds are frequently used.
[0158] By substantially linear" is meant that the alkyl group is straight chain although
alkyl groups having a small degree of branching such as in the form of a single methyl
group branch may be used.
[0159] The oxygen atom or atoms, if present, may be directly interposed between carbon atoms
in the chain and may be provided in the linking group, if present, in the form of
a mono-or poly-oxyalkylene group, the oxyalkylene group may have 2 to 4 carbon atoms.
Examples include oxyethylene and oxypropylene.
[0160] The linear compound may be an ester, the alkyl groups of which may be derived from
an acid and the remainder of the compound may be derived from a polyhydric alcohol
or vice-versa. Alternatively, the linear compound may be an ether or a mixed ester/ether,
It may contain different ester groups.
[0161] Examples of linear compounds which may be used include polyoxyalkylene esters, ethers,
ester/ethers, and mixtures thereof, particularly those containing at least one, and
in some cases at least two, C
10-30 linear alkyl groups and a polyoxyalkylene glycol group of number average molecular
weight (by GPC) up to 5,000, such as 200 to 5,000 (see
EP-A-61895 and in
U.S. Pat. No. 4,491,455).
[0162] Polyoxyalkylene diesters, diethers, ether/esters, and mixtures thereof are also suitable
as the cold flow improver. Suitable examples include the stearic or behenic diesters
of polyethylene glycol, polypropylene glycol, or polyethylene/polypropylene glycol
mixtures.
[0164] As noted above, mixtures of these cold flow improvers may be use, for example mixtures
of ethylene-unsaturated ester copolymers and comb polymers, for example a mixture
of an ethylene-vinyl acetate copolymer and a fumarate comb polymer.
Combustion Improvers
[0165] Suitable combustion improvers may comprise one or more of a manganese compound, ferrocene,
platinum, cerium, cerium oxide, and the like. For example, a non-limiting example
of a useful manganese compound is an alkylcycloalkyldienyl manganese tricarbonyl,
such as methylcyclopentadienyl manganese tricarbonyl. It generally is added in treat
rates of about 0.0156 to about 0.125 gram of manganese per gallon of fuel.
[0166] Cyclopentadienyl manganese tricarbonyl compounds such as methylcyclopentadienyl manganese
tricarbonyl are suitable combustion improvers because of their outstanding ability
to reduce tailpipe emissions such as NO
x and smog forming precursors and to significantly improve the octane quality of gasolines,
both of the conventional variety and of the "reformulated" types.
Corrosion Inhibitors
[0167] A variety of materials are available for use as corrosion inhibitors in the practice
of embodiments disclosed herein. Thus, use can be made of dimer and trimer acids,
such as are produced from tall oil fatty acids, oleic acid, linoleic acid, or the
like. Another useful type of corrosion inhibitor for use in the practice of this invention
are the alkenyl succinic acid and alkenyl succinic anhydride corrosion inhibitors
such as, for example, tetrapropenylsuccinic acid, tetrapropenylsuccinic anhydride,
tetradecenylsuccinic acid, tetradecenylsuccinic anhydride, hexadecenylsuccinic acid,
hexadecenylsuccinic anhydride, and the like. Also useful are the half esters of alkenyl
succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols such
as the polyglycols. Further suitable materials are the aminosuccinic acids or derivatives
thereof, such as a tetralkenyl succinic acid.
Demulsifiers
[0168] A wide variety of demulsifiers may be suitable for use with embodiments disclosed
herein, including, for example, polyoxyalkylene glycols, oxyalkylated phenolic resins,
and like materials.
Detergents
[0169] Metal-containing or ash-forming detergents function both as detergents to reduce
or remove deposits and as acid neutralizers or corrosion inhibitors, thereby reducing
wear, deposits and corrosion and extending engine life for engines combusting fuel
formulations. Detergents generally comprise a polar head with a long hydrophobic tail
where the polar head comprises a metal salt of an acidic organic compound. The salts
may contain a substantially stoichiometric amount of the metal, in which case they
are usually described as normal or neutral salts, and would typically have a total
base number or TBN (as measured by ASTM D2896) of from 0 to less than 150. Large amounts
of a metal base may be included by reacting an excess of a metal compound such as
an oxide or hydroxide with an acidic gas such as carbon dioxide. The resulting overbased
detergent comprise micelles of neutralized detergent surrounding a core of inorganic
metal base (e.g., hydrated carbonates). Such overbased detergents may have a TBN of
150 or greater, and typically ranging from 250 to 450 or more.
[0170] Suitable detergents for use in some embodiments may comprise one or more of Mannich
base detergents, polyetheramines, and combinations thereof.
[0171] Suitable Mannich base detergents may comprise the reaction products of an alkyl-substituted
hydroxy aromatic compound, aldehydes, and amines. The alkyl-substituted hydroxyaromatic
compound, aldehydes and amines used in making the Mannich reaction products of the
present invention may be any such compounds known and applied in the art, in accordance
with the foregoing limitations.
[0172] Representative alkyl-substituted hydroxyaromatic compounds that may be used in forming
the present Mannich base products are polypropylphenol (formed by alkylating phenol
with polypropylene), polybutylphenols (formed by alkylating phenol with polybutenes
and/or polyisobutylene), and polybutyl-co-polypropylphenols (formed by alkylating
phenol with a copolymer of butylene and/or butylene and propylene). Other similar
long-chain alkylphenols may also be used. Examples include phenols alkylated with
copolymers of butylene and/or isobutylene and/or propylene, and one or more mono-olefinic
comonomers copolymerizable therewith (e.g., ethylene, 1-pentene, 1-hexene, 1-octene,
1-decene, etc.) where the copolymer molecule contains at least 50% by weight, of butylene
and/or isobutylene and/or propylene units. The comonomers polymerized with propylene
or such butenes may be aliphatic and can also contain non-aliphatic groups, e.g.,
styrene, o-methylstyrene, p-methylstyrene, divinyl benzene and the like. Thus in any
case the resulting polymers and copolymers used in forming the alkyl-substituted hydroxyaromatic
compounds are substantially aliphatic hydrocarbon polymers.
[0173] In some embodiments, polybutylphenol (formed by alkylating phenol with polybutylene)
may be used in forming the Mannich base detergent. Unless otherwise specified herein,
the term "polybutylene" is used in a generic sense to include polymers made from "pure"
or "substantially pure" 1-butene or isobutene, and polymers made from mixtures of
two or all three of 1-butene, 2-butene, and isobutene. Commercial grades of such polymers
may also contain insignificant amounts of other olefins. So-called high reactivity
polybutylenes having relatively high proportions of polymer molecules having a terminal
vinylidene group, formed by methods such as described, for example, in
U.S. Pat. No. 4,152,499 and W. German Offenlegungsschrift
29 04 314, are also suitable for use in forming the long chain alkylated phenol reactant.
[0174] The alkylation of the hydroxyaromatic compound is typically performed in the presence
of an alkylating catalyst at a temperature in the range of about 50 to about 200 °C.
Acidic catalysts are generally used to promote Friedel-Crafts alkylation. Typical
catalysts used in commercial production include sulphuric acid, BF
3, aluminum phenoxide, methanesulphonic acid, cationic exchange resin, acidic clays,
and modified zeolites.
[0175] The long chain alkyl substituents on the benzene ring of the phenolic compound are
derived from polyolefin having a number average molecular weight (MW of from about
500 to about 3000 (preferably from about 500 to about 2100) as determined by gel permeation
chromatography (GPC). It is also preferred that the polyolefin used have a polydispersity
(weight average molecular weight/number average molecular weight) in the range of
about 1 to about 4 (preferably from about 1 to about 2) as determined by GPC.
[0176] The Mannich detergent may be made from a long chain alkylphenol. However, other phenolic
compounds may be used including high molecular weight alkyl-substituted derivatives
ofresorcinol, hydroquinone, catechol, hydroxydiphenyl, benzylphenol, phenethylphenol,
naphthol, tolylnaphthol, among others. Preferred for the preparation of the Mannich
condensation products are the polyalkylphenol and polyalkylcresol reactants, e.g.,
polypropylphenol, polybutylphenol, polypropyleresol, and polybutylcresol, wherein
the alkyl group has a number average molecular weight of about 500 to about 2100,
while the most preferred alkyl group is a polybutyl group derived from polybutylene
having a number average molecular weight in the range of about 800 to about 1300.
[0177] The preferred configuration of the alkyl-substituted hydroxyaromatic compound is
that of a para-substituted mono-alkylphenol or a para-substituted mono-alkyl ortho-cresol.
However, any alkylphenol readily reactive in the Mannich condensation reaction may
be employed. Thus, Mannich products made from alkylphenols having only one ring alkyl
substituent, or two or more ring alkyl substituents are suitable. The long chain alkyl
substituents may contain some residual unsaturation, but in general, are substantially
saturated alkyl groups.
[0178] Representative amine reactants include, but are not limited to, linear, branched,
or cyclic alkylene monoamines or polyamines having at least one suitably reactive
primary or secondary amino group in the molecule. Other substituents such as hydroxyl,
cyano, amido, etc., can be present in the amine. In some embodiments, the alkylene
polyamine is a polyethylene polyamine. Suitable alkylene polyamine reactants include
ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine,
pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, octaethylenenonamine,
nonaethylenedecamine, decaethyleneundecamine and mixtures of such amines having nitrogen
contents corresponding to alkylene polyamines of the formula H
2N-(A-NH--)
nH, where A is divalent ethylene or propylene and n is an integer of from 1 to 10.
The alkylene polyamines may be obtained by the reaction of ammonia and dihaloalkanes,
such as dichloro alkanes. Thus, the alkylene polyamines obtained from the reaction
of 2 to 11 moles of ammonia with 1 to 10 moles of dichloro alkanes having 2 to 6 carbon
atoms and the chlorines on different carbon atoms are suitable alkylene polyamine
reactants.
[0179] In another preferred embodiment of the present invention, the amine is an aliphatic
linear, branched, or cyclic diamine having one primary or secondary amino group and
one tertiary amino group in the molecule. Examples of suitable polyamines include
N,N,N",N"-tetraalkyl-dialkylenetriamines (two terminal tertiary amino groups and one
central secondary amino group), N,N,N',N"-tetraalkyltrialkylenetetramines (one terminal
tertiary amino group, two internal tertiary amino groups and one terminal primary
amino group), N,N,N',N",N"'-pentaalkyltrialkylene-tetramines (one terminal tertiary
amino group, two internal tertiary amino groups and one terminal secondary amino group),
N,N-dihydroxyalkyl-alpha, omega-alkylenediamines (one terminal tertiary amino group
and one terminal primary amino group), N,N,N'-trihydroxy-alkyl-alpha, omega-alkylenediamines
(one terminal tertiary amino group and one terminal secondary amino group), tris(dialkylaminoalkyl)aminoalkylmethanes
(three terminal tertiary amino groups and one terminal primary amino group), and like
compounds, wherein the alkyl groups are the same or different and typically contain
no more than about 12 carbon atoms each, and which preferably contain from 1 to 4
carbon atoms each. These alkyl groups are typically methyl and/or ethyl groups. Typical
polyamine reactants are N,N-dialkyl-alpha, omega-alkylenediamine, such as those having
from 3 to about 6 carbon atoms in the alkylene group and from 1 to about 12 carbon
atoms in each of the alkyl groups, which most preferably are the same but which can
be different. Also suitable is N,N-dimethyl-1,3-propanediamine and N-methyl piperazine.
[0180] Examples of polyamines having one reactive primary or secondary amino group that
can participate in the Mannich condensation reaction, and at least one sterically
hindered amino group that cannot participate directly in the Mannich condensation
reaction to any appreciable extent include N-(tert-butyl)-1,3-propanediamine, N-neopentyl-1,3-propanediamine,
N-(tert-butyl)-1-methyl-1,2-ethanediamine, N-(tert-butyl)-1-methyl-1,3-propanediamine,
and 3,5-di(tert-butyl)aminoethy-1-piperazine.
[0181] Representative aldehydes for use in the preparation of the Mannich base products
include the aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde,
butyraldehyde, valeraldehyde, caproaldehyde, heptaldehyde, and stearaldehyde. Aromatic
aldehydes which may be used include benzaldehyde and salicylaldehyde. Illustrative
heterocyclic aldehydes for use herein are furfural and thiophene aldehyde, etc. Also
useful are formaldehyde-producing reagents such as paraformaldehyde, or aqueous formaldehyde
solutions such as formalin.
[0182] The condensation reaction among the alkylphenol, the specified amine(s) and the aldehyde
may be conducted at a temperature in the range of about 40 to about 200°C. The reaction
can be conducted in bulk (no diluent or solvent) or in a solvent or diluent. Water
is evolved and can be removed by azeotropic distillation during the course of the
reaction. Typically, the Mannich reaction products are formed by reacting the alkyl-substituted
hydroxyaromatic compound, the amine and aldehyde in the molar ratio of 1.0:0.5-2.0:1.0-3.0,
respectively.
[0183] Suitable Mannich base detergents may also include those detergents taught in
U.S. Pat. Nos. 4,231,759;
5,514,190;
5,634,951;
5,697,988;
5,725,612; and
5,876,468, the disclosures of which are incorporated herein by reference.
[0184] Preparation of polyetheramine compounds useful as the detergent is described in the
literature, for example, U.S. Pat. No., the disclosure of which is incorporated herein
in its entirety.
[0185] Suitable polyetheramines may comprise "single molecule" additives, incorporating
both amine and polyether functionalities within the same molecule. The polyether backbone
can in one embodiment herein be based on propylene oxide, ethylene oxide, butylene
oxide, or mixtures of these. The polyetheramines can be monoamines, diamines, or triamines.
[0186] Detergents that may be used include oil-soluble neutral and overbased sulfonates,
phenates, sulfurized phenates, and salicylates of a metal, particularly the alkali
or alkaline earth metals, e.g., sodium, potassium, lithium, calcium, and magnesium.
The most commonly used metals are calcium and magnesium, which may both be present.
Mixtures of calcium and/or magnesium with sodium are also useful. Particularly convenient
metal detergents are neutral and overbased calcium or magnesium sulfonates having
a TBN of from 20 to 450 TBN, neutral and overbased calcium or magnesium phenates and
sulfurized phenates having a TBN of from 50 to 450, and neutral or overbased calcium
or magnesium salicylates having a TBN of from 130 to 350. Mixtures of such salts may
also be used. When used, the presence of at least one overbased detergent is desirable.
[0187] Sulfonates may be prepared from sulfonic acids which are typically obtained by the
sulfonation of alkyl substituted aromatic hydrocarbons such as those obtained from
the fractionation of petroleum or by the alkylation of aromatic hydrocarbons. Examples
include those obtained by alkylating benzene, toluene, xylene, naphthalene, diphenyl
or their halogen derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene.
The alkylation may be carried out in the presence of a catalyst with alkylating agents
having from 3 to more than 70 carbon atoms. The alkaryl sulfonates usually contain
from 9 to 80 or more carbon atoms, typically from 16 to 60 carbon atoms per alkyl
substituted aromatic moiety.
[0188] The oil-soluble sulfonates or alkaryl sulfonic acids may be neutralized with oxides,
hydroxides, alkoxides, carbonates, carboxylate, sulphides, hydrosulfides, nitrates,
borates and ethers of the alkali metal. The amount of metal compound is chosen having
regard to the desired TBN of the final product but typically ranges from 100 to 220
wt % (desirably at least 125 wt %) of that stoichiometrically required.
[0189] Metal salts of alkyl phenols and sulfurized alkyl phenols are prepared by reaction
with an appropriate metal compound such as an oxide, hydroxide or alkoxide, and overbased
products may be obtained by methods well known in the art. Sulfurized alkyl phenols
may be prepared by reacting an alkyl phenol with sulphur or a sulphur-containing compound
such as hydrogen sulphide, sulphur monohalide or sulphur dihalide, to form products
which are generally mixtures of compounds in which 2 or more phenols are bridged by
sulphur-containing bridges. The starting alkyl phenol may contain one or more alkyl
substituents. These may be branched or unbranched, and depending on the number of
substituents may have from 1 to 30 carbon atoms (provided the resulting alkyl phenol
is oil-soluble), with from 9 to 18 carbon atoms being particularly suitable. Mixtures
of alkyl phenols with different alkyl substituents may be used.
[0190] Metal salts of carboxylic acids (including salicylic acids) may be prepared in a
number of ways: for example, by adding a basic metal compound to a reaction mixture
comprising the carboxylic acid (which may be part of a mixture with another organic
acid such as a sulfonic acid) or its metal salt and promoter, and removing free water
from the reaction mixture to form an metal salt, then adding more basic metal compound
to the reaction mixture and removing free water from the reaction mixture. The carboxylate
is then overbased by introducing the acidic material such as carbon dioxide to the
reaction mixture while removing water. This can be repeated until a product of the
desired TBN is obtained.
[0191] The overbasing process is well known in the art and typically comprises reacting
acidic material with a reaction mixture comprising the organic acid or its metal salt,
a metal compound. That acidic material may be a gas such as carbon dioxide or sulphur
dioxide, or it may be boric acid. Processes for the preparation of overbased alkali
metal sulfonates and phenates are described in
U.S. Pat. No. 4,839,094. A process suitable for overbased sodium sulfonates is described in
EP-A-235929. A process for making overbased salicylates is described in
U.S. Pat. No. 5,451,331.
Deposit Inhibitor Compound/Dispersants
[0192] The dispersants useful in the fuel compositions described herein include at least
one oil-soluble ashless dispersant having a basic nitrogen and/or at least one hydroxyl
group in the molecule. Suitable dispersants include alkenyl succinimides, alkenyl
succinic acid esters, alkenyl succinic ester-amides, and Mannich bases.
[0193] Suitable succinimides, for example, include alkenyl succinimides comprising the reaction
products obtained by reacting an alkenyl succinic anhydride, acid, acid-ester or lower
alkyl ester with an amine containing at least one primary amine group. Representative
non-limiting examples are given in
U.S. Pat. Nos. 3,172,892;
3,202,678;
3,219,666;
3,272,746,
3,254,025,
3,216,936,
4,234,435; and
5,575,823. The alkenyl succinic anhydride may be prepared readily by heating a mixture of olefin
and maleic anhydride to about 180-220 °C.The olefin is, in an embodiment, a polymer
or copolymer of a lower monoolefin such as ethylene, propylene, isobutene and the
like. In another embodiment the source of alkenyl goup is from polyisobutene having
a molecular weight up to 10,000 or higher. In another embodiment the alkenyl is a
polyisobutene group having a molecular weight of about 200-5,000 or, in another example,
about 700-2,100.
[0194] Amines which may be employed include any that have at least one primary amine group
which can react to form an imide group. A few representative examples are: methylamine,
2-ethylhexylamine, n-dodecylamine, stearylamine, N,N-dimethyl-propanediamine, N-(3-aminopropyl)morpholine,
N-dodecyl propanediamine, N-aminopropyl piperazine ethanolamine, N-ethanol ethylene
diamine and the like. Other suitable amines include the alkylene polyamines such as
propylene diamine, dipropylene triamine, di-(1,2-butylene)-triamine, tetra-(1,2-propylene)pentaamine.
[0195] In one embodiment the amines are the ethylene polyamines that have the formula H
2N(CH
2CH
2NH)
nH wherein n is an integer from one to ten. These ethylene polyamines include ethylene
diamine, diethylene triamine, triethylene tetraamine, tetraethylene pentaamine, pentaethylene
hexaamine, and the like, including mixtures thereof in which case n is the average
value of the mixture. These ethylene polyamines have a primary amine group at each
end so can form mono-alkenylsuccinimides and bis-alkenylsuccinimides.
[0196] Thus ashless dispersants for use in the present invention also include the products
of reaction of a polyethylenepolyamine, e.g. triethylene tetramine or tetraethylene
pentamine, with a hydrocarbon substituted carboxylic acid or anhydride made by reaction
of a polyolefin, such as polyisobutene, having a molecular weight of 500 to 5,000,
especially 700 to 2000, with an unsaturated polycarboxylic acid or anhydride, e.g.
maleic anhydride.
[0197] Also suitable for use as the succinimides are succinimide-amides prepared by reacting
a succinimide-acid with a polyamine or partially alkoxylated polyamine, as taught
in
U.S. Pat. No. 6,548,458. The succinimide-acid compounds of the present invention are prepared by reacting
an alpha-omega amino acid with an alkenyl or alkyl-substituted succinic anhydride
in a suitable reaction media. Suitable reaction media include, but are not limited
to, an organic solvent, such as toluene, or process oil. Water is a by-product of
this reaction. The use of toluene allows for azeotropic removal of water.
[0198] The mole ratio of maleic anhydride to olefin can vary widely. It may vary, in one
example, from 5:1 to 1:5, and in another example the range is 3:1 to 1:3 and in yet
another embodiment the maleic anhydride is used in stoichiometric excess, e.g. 1.1
to 5 moles maleic anhydride per mole of olefin. The unreacted maleic anhydride can
be vaporized from the resultant reaction mixture.
[0199] The alkyl or alkenyl-substituted succinic anhydrides may be prepared by the reaction
of maleic anhydride with the desired polyolefin or chlorinated polyolefin, under reaction
conditions well known in the art. For example, such succinic anhydrides may be prepared
by the thermal reaction of a polyolefin and maleic anhydride, as described, for example
in
U.S. Pat. Nos. 3,361,673 and
3,676,089. Alternatively, the substituted succinic anhydrides can be prepared by the reaction
of chlorinated polyolefins with maleic anhydride, as described, for example, in
U.S. Pat. No. 3,172,892. A further discussion of hydrocarbyl-substituted succinic anhydrides can be found,
for example, in
U.S. Pat. Nos. 4,234,435;
5,620,486 and
5,393,309.
[0200] Polyalkenyl succinic anhydrides may be converted to polyalkyl succinic anhydrides
by using conventional reducing conditions such as catalytic hydrogenation. For catalytic
hydrogenation, a suitable catalyst is palladium on carbon. Likewise, polyalkenyl succinimides
may be converted to polyalkyl succinimides using similar reducing conditions.
[0201] The polyalkyl or polyalkenyl substituent on the succinic anhydrides employed in the
invention is generally derived from polyolefins which are polymers or copolymers of
mono-olefins, particularly 1-mono-olefins, such as ethylene, propylene, butylene,
and the like. The mono-olefin employed may have 2 to about 24 carbon atoms, or as
another example, about 3 to 12 carbon atoms. Also, the mono-olefins can include propylene,
butylene, particularly isobutylene, 1-octene, and 1-decene. Polyolefins prepared from
such mono-olefins include polypropylene, polybutene, polyisobutene, and the polyalphaolefins
produced from 1-octene and 1-decene.
[0202] In one embodiment the polyalkyl or polyalkenyl substituent is one derived from polyisobutene.
Suitable polyisobutenes for use in preparing the succinimide-acids of the present
invention include those polyisobutenes that comprise at least about 20% of the more
reactive methylvinylidene isomer, such as at least 50% and further such as at least
70%. Suitable polyisobutenes include those prepared using BF
3 catalysts. The preparation of such polyisobutenes in which the methylvinylidene isomer
comprises a high percentage of the total composition is described in
U.S. Pat. Nos. 4,152,499 and
4,605,808. Examples of suitable polyisobutenes having a high alkylvinylidene content include
a polyisobutene having a number average molecular weight of about 1300 and a methylvinylidene
content of about 74%, and a polyisobutene having a number average molecular weight
of about 950 and a methylvinylidene content of about 76%, and materials comprising
the beta isomer thereof.
[0203] Suitable alpha-omega amino acids are disclosed in
U.S. Pat. No. 6,548,458 which is incorporated herein by reference in its entirety. Suitable alpha-omega amino
acids include glycine, beta-alanine, gamma-amino butyric acid, 6-amino caproic acid,
11-amino undecanoic acid.
[0204] The molar ratio of anhydride to alpha-omega amino acid ranges from 1:10 to 1:1, and
as another example, the molar ratio of anhydride to alpha-omega amino acid is 1:1.
[0205] The succinimide-acid compounds are typically prepared by combining the substituted-succinic
anhydride and amino acid with a reaction media in a suitable reaction vessel. When
the reaction media used is process oil, the reaction mixture is heated to between
120 and 180 °C under nitrogen. The reaction generally requires 2 to 5 hours for complete
removal of water and formation of the succinimide product. When toluene (or other
organic solvent) is used as the reaction media, the reflux temperature of the water/toluene
(solvent) azeotrope determines the reaction temperature.
[0206] Reaction of the pendant carboxylic acid moiety of the succinimide-acid compound with
an amine results in the formation of an amide bond. The reaction is conducted at a
temperature and for a time sufficient to form the succinimide-amide reaction product.
Typically, the reaction is conducted in a suitable reaction media such as an organic
solvent, for example, toluene, or process oil. The reaction is typically conducted
at a temperature of from 110 to 180°C for 2 to 8 hours.
[0207] The ratio of succinimide-acid compound to polyamine ranges from n: 1 to 1:1 where
n is the number of reactive nitrogen atoms (i.e., unhindered primary and secondary
amines capable of reacting with the succinimide-acid) within the polyamine.
[0208] In one embodiment the amines are polyamines and partially alkoxylated polyamines.
Examples of polyamines that may be used include, but are not limited to, aminoguanidine
bicarbonate (AGBC), diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene
pentamine (TEPA), pentaethylene hexamine (PEHA), and heavy polyamines. A heavy polyamine
is a mixture of polyalkylenepolyamines comprising small amounts of lower polyamine
oligomers such as TEPA and PEHA but primarily oligomers with 7 or more nitrogens,
2 or more primary amines per molecule, and more extensive branching than conventional
polyamine mixtures. Examples of a partially alkoxylated polyamines include aminoethylethanolamine
(AEEA), aminopropyldiethanolamine (APDEA), diethanolamine (DEA), and partially propoxylated
hexamethylenediamine (for example HMDA-2PO or HMDA-3PO). When partially alkoxylated
polyamines are used, the reaction products of the succinimide-acid and the partially
alkoxylated polyamine may contain mixtures of succinimide-amides and succinimide-esters
as well as any unreacted components.
[0209] In one embodiment, the fuels will contain minor amounts of the triazine compounds
that control, eliminate, or reduce formation of engine deposits, especially injector
deposits and/or control soot formation. Generally speaking the fuels of the invention
will contain an amount of the triazine compound sufficient to provide from about 0.0078
to about 0.25 gram of manganese per gallon of fuel, and preferably from about 0.0156
to about 0.125 gram of manganese per gallon.
[0210] The Mannich base dispersants are usually a reaction product of an alkyl phenol, typically
having a long chain alkyl substituent on the ring, with one or more aliphatic aldehydes
containing from 1 to about 7 carbon atoms (especially formaldehyde and derivatives
thereof), and polyamines (especially polyalkylene polyamines). Examples of Mannich
condensation products, and methods for their production are described in
U.S. Pat. Nos. 2,459,112;
2,962,442;
2,984,550;
3,036,003;
3,166,516;
3,236,770;
3,368,972;
3,413,347;
3,442,808;
3,448,047;
3,454,497;
3,459,661;
3,493,520;
3,539,633;
3,559,743;
3,586,629;
3,591,598;
3,600,372;
3,634,515;
3,649,229;
3,697,574;
3,703,536;
3,704,308;
3,725,277;
3,725,480;
3,726,882;
3,736,357;
3,751,365;
3,756,953;
3,793,202;
3,798,165;
3,798,247;
3,803,039;
3,872,019;
3,904,595;
3,957,746;
3,980,569;
3,985,802;
4,006,089;
4,011,380;
4,025,451;
4,058,468;
4,083,699;
4,090,854;
4,354,950; and
4,485,023.
[0211] The various types of ashless dispersants described above can be phosphorylated by
procedures described in
U.S. Pat. Nos. 3,184,411;
3,342,735;
3,403,102;
3,502,607;
3,511,780;
3,513,093;
3,513,093;
4,615,826;
4,648,980;
4,857,214 and
5,198,133.
[0212] The dispersants of the present disclosure may be boronated. Methods for boronating
(borating) the various types of ashless dispersants described above are described
in
U.S. Pat. Nos. 3,087,936;
3,254,025;
3,281,428;
3,282,955;
2,284,409;
2,284,410;
3,338,832;
3,344,069;
3,533,945;
3,658,836;
3,703,536;
3,718,663;
4,455,243; and
4,652,387.
[0213] Suitable procedures for phosphorylating and/or boronating ashless dispersants such
as those referred to above are set forth in
U.S. Pat. Nos. 4,857,214 and
5,198,133.
Viscosity Modifiers
[0214] Viscosity modifiers for use in finished fuel compositions as described herein may
comprise an olefin (co)polymer(s). A suitable viscosity modifier may include a mixture
of olefin (co)polymers. A fully formulated fuel composition as described herein may
contain 0.1 to 40 wt. % olefin (co)polymer.
[0215] The olefin (co)polymer which may be used is a homopolymer, copolymer, or terpolymer
resulting from the polymerization of C
2-C
10 olefins having a number average molecular weight of from about 1,000 to about 10,000,
for example, about 1,000 to about 3,000, as determined by gel permeation chromatography
(GPC). The C
2-C
10 olefins include ethylene, propylene, 1-butene, isobutylene, 2-butene, isoprene, 1-octene,
and 1-decene. Exemplary (co)polymers include polypropylene, polyisobutylene, ethylene/propylene
copolymers, styrene/isoprene copolymers, and 1-butene/isobutylene copolymers, and
mixtures of the polymers thereof.
Friction Modifiers and Lubricity Additives
[0216] For certain applications it may be desirable to use one or more friction modifiers
also referred to as lubricity additives in preparing the finished fuel formulation.
Suitable lubricity additives include such compounds as aliphatic fatty acid amides,
aliphatic carboxylic acids, aliphatic carboxylic esters, aliphatic carboxylic ester-amides,
aliphatic amines, or mixtures thereof. The aliphatic group typically contains at least
about eight carbon atoms so as to render the compound suitably fuel soluble. Also
suitable are aliphatic substituted succinimides formed by reacting one or more aliphatic
succinic acids or anhydrides with ammonia.
[0217] The use of lubricity additives is optional and will depend of the inherent lubricity
of the fuel. However, in applications where friction modifiers are used, finished
fuel formulations may contain up to about 1.25 wt %, and usually from about 0.05 to
about 1 wt % of one or more friction modifiers.
Inhibitors
[0218] Finished fuel compositions as described herein typically will contain some inhibitors.
The inhibitor components serve different functions including corrosion inhibition
and foam inhibition. The inhibitors may be introduced in a pre-formed additive package
that may contain in addition one or more other components used in the finished fuel
compositions. Alternatively these inhibitor components may be introduced individually
or in various sub-combinations. While amounts of inhibitors used may be varied within
reasonable limits, the finished fuel compositions of this disclosure will typically
have a total inhibitor content in the range of about 0 to about 15 wt %, on an "active
ingredient basis," i.e., excluding the weight of inert materials such as solvents
or diluents normally associated therewith.
[0219] Foam inhibitors form one type of inhibitor suitable for use as an inhibitor component
in the finished fuel compositions. Useful foam inhibitors include silicones, surfactants,
and the like.
[0220] Corrosion inhibitors constitute another class of additives suitable for inclusion
in the finished fuel compositions. Such compounds include thiazoles, triazoles and
thiadiazoles. Examples of such compounds include benzotriazole, tolyltriazole, octyltriazole,
decyltriazole, dodecyltriazole, 2-mercapto benzothiazole, 2,5-dimercapto-1,3,4-thiadiazole,
2-mercapto-5-hydrocarbyhhio-1,3,4-thiadiazoles, 2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazoles,
2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles, and 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles.
In one embodiment the compounds are the 1,3,4-thiadiazoles, a number of which are
available as articles of commerce, and also combinations of triazoles such as tolyltriazole
with a 1,3,5-thiadiazole such as a 2,5-bis(alkyldithio)-1,3,4-thiadiazole. The 1,3,4-thiadiazoles
are generally synthesized from hydrazine and carbon disulfide by known procedures.
See, for example,
U.S. Pat. Nos. 2,765,289;
2,749,311;
2,760,933;
2,850,453;
2,910,439;
3,663,561;
3,862,798; and
3,840,549. Further suitable corrosion inhibitors may include monocarboxylic acids and polycarboxylic
acids. Examples of suitable monocarboxylic acids are octanoic acid, decanoic acid
and dodecanoic acid. Suitable polycarboxylic acids include dimer and trimer acids
such as are produced from such acids as tall oil fatly acids, oleic acid, linoleic
acid, or the like.
[0221] Another useful type of corrosion inhibitor for use in the disclosed fuel compositions
is comprised of the alkenyl succinic acid and alkenyl succinic anhydride corrosion
inhibitors such as, for example, tetrapropenylsuccinic acid, tetrapropenylsuccinic
anhydride, tetradecenylsuccinic acid, tetradecenylsuccinic anhydride, hexadecenylsuccinic
acid, hexadecenylsuccinic anhydride, and the like. Also useful are the half esters
of alkenyl succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols
such as the polyglycols. Other suitable corrosion inhibitors include acid phosphates;
ethoxylated phenols, and ethoxylated alcohols; imidazolines; aminosuccinic acids or
derivatives thereof, and the like. Materials of these types are available as articles
of commerce. Mixtures of such corrosion inhibitors can be used.
Antiwear Agents
[0222] Various types of sulfur-containing antiwear agents may be used in the finished fuel
formulations described herein. Examples include dihydrocarbyl polysulfides; sulfurized
olefins; sulfurized fatty acid esters of both natural and synthetic origins; trithiones;
sulfurized thienyl derivatives; sulfurized terpenes; sulfurized oligomers of C2-C8
monoolefins; and sulfurized Diels-Alder adducts such as those disclosed in
U.S. Pat. No. Re 27,331. Specific examples include sulfurized polyisobutene, sulfurized isobutylene, sulfurized
diisobutylene, sulfurized triisobutylene, dicyclohexyl polysulfide, diphenyl polysulfide,
dibenzyl polysulfide, dinonyl polysulfide, and mixtures of di-tert-butyl polysulfide
such as mixtures of di-tert-butyl trisulfide, di-tert-butyl tetrasulfide and di-tert-butyl
pentasulfide, among others. Combinations of such categories of sulfur-containing antiwear
agents may also be used, such as a combination of sulfurized isobutylene and di-tert-butyl
trisulfide, a combination of sulfurized isobutylene and dinonyl trisulfide, a combination
of sulfurized tall oil and dibenzyl polysulfide.
Pour point depressants
[0223] The fuel additive package or fuel composition may also contain one or more pour point
depressants. Pour point depressants may be used in compositions described herein to
improve low temperature properties of the compositions. Examples of useful pour point
depressants are polyaorylamides; condensation products of haloparaffin waxes and aromatic
compounds; vinyl carboxylate polymers; and terpolymers of dialkylfumarates, vinyl
esters of fatty acids and alkyl vinyl ethers. Pour point depressants useful for the
purposes of this disclosure and techniques for their preparation are described in
U.S. Pat. Nos. 2,387,501;
2,015,748;
2,655,479;
1,815,022;
2,191,498;
2,666,746;
2,721,877;
2,721,878; and
3,250,715 which are herein incorporated by reference for their relevant disclosures.
[0224] In one embodiment, the pour point depressant is represented by the general structural
formula: Ar(R)-(Ar
1(R
1))
n-Ar
2, wherein the Ar, Ar
1 and Ar
2 are aromatic groups of up to about 12 carbon atoms, (R) and (R
1) are independently an alkylene group containing 1 to 100 carbon atoms with the proviso
that at least one of (R) or (R
1) is CH
2, and n is 0 to about 1000 with the proviso that if n is 0, then (R) is CH
2 and at least one aromatic moiety has at least one substituent, the substituents being
selected from the group consisting of a substituent derived from an olefin containing
about 8 to about 30 carbon atoms, and a substituent derived from a chlorinated hydrocarbon
usually containing about 8 to about 50 carbon atoms and about 2.5 chlorine atoms for
each 24 carbon atoms.
Seal swell agents
[0225] Seal swell agents may be included in the finished fuel compositions of the disclosed
embodiments particularly when the fuel compositions are used as power transmission
fluids. Suitable seal swell agents may be selected from oil-soluble diesters, oil-soluble
sulfones, silicon containing organic compounds, and mixtures thereof. Generally speaking
the most suitable diesters include the adipates, azelates, and sebacates of C8-C13
alkanols (or mixtures thereof), and the phthalates of C4-C13 alkanols (or mixtures
thereof). Mixtures of two or more different types of diesters (e.g., dialkyl adipates
and dialkyl azelates, etc.) may also be used. Examples of such materials include the
n-octyl, 2-ethylhexyl, isodecyl, and tridecyl diesters of adipic acid, azelaic acid,
and sebacic acid, and the n-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl,
decyl, undecyl, dodecyl, and tridecyl diesters of phthalic acid. Other esters which
may give generally equivalent performance are polyol esters.
[0226] Suitable sulfone seal swell agents are described in
U.S. Pat. Nos. 3,974,081 and
4,029,587. Typically these products are employed at levels in the range of about 0.25 to about
1 wt % in the finished transmission fluid.
[0227] In one embodiment, the seal swell agents are the oil-soluble dialkyl esters of (i)
adipic acid, (ii) sebacic acid, or (iii) phthalic acid. The adipates and sebacates
should be used in amounts in the range of from about 4 to about 15 wt % in the finished
fuel. In the case of the phthalates, the levels in the fuel should fall in the range
of from about 1.5 to about 10 wt %. Generally speaking, the higher the molecular weight
of the adipate, sebacate or phthalate, the higher should be the treat rate within
the foregoing ranges.
Thickening agents
[0228] A wide variety of thickening agents may be used for providing fuels containing the
base oil component. Included among the thickening agents are alkali and alkaline earth
metal soaps of fatty acids and fatty materials having from about 12 to about 30 carbon
atoms per molecule. The metal cations of the metal soaps are typified by sodium, lithium,
calcium, magnesium, and barium. Fatty materials are illustrated by stearic acid, hydroxystearic
acid, stearin, cottonseed oil acids, oleic acid, palmitic acid, myristic acid and
hydrogenated fish oils.
[0229] Other thickening agents include salt and salt-soap complexes such as calcium stearate-acetate
(
U.S. Pat. No. 2,197,263), barium stearate acetate (
U.S. Pat. No. 2,564,561), calcium stearate-caprylate-acetate complexes (
U.S. Pat. No. 2,999,065), calcium-caprylate-acetate (
U.S. Pat. No. 2,999,066), and calcium salts and soaps of low-, intermediate-, and high-molecular weight acids
and of nut oil acids. Another group of thickening agents comprises substituted ureas,
phthalocyanines, indanthrene, pigments such as perylimides, pyromellitdiimides, ammeline,
and hydrophobic clays.
[0230] Some of the additive components described above may be supplied in the form of solutions
of active ingredient(s) in an inert diluent or solvent, such as a diluent oil. Unless
expressly stated to the contrary, the amounts and concentrations of each additive
component are expressed in terms of active additive, i.e., the amount of solvent or
diluent that may be associated with such component as received is excluded.
[0231] It will be appreciated that the individual components employed may be separately
blended into the fuel or carrier fluid or may be blended therein in various sub-combinations,
if desired. Ordinarily, the particular sequence of such blending steps is not crucial.
Moreover, such components may be blended in the form of separate solutions in a diluent.
It may be preferable, however, to blend the additive components used in the form of
a concentrate, as this simplifies the blending operations, reduces the likelihood
of blending errors, and takes advantage of the compatibility and solubility characteristics
afforded by the overall concentrate.
[0232] Additive concentrates may thus be formulated to contain all of the additive components
and if desired, some of the base fuel component, in amounts proportioned to yield
finished fuel blends consistent with the concentrations described above. In most cases,
the additive concentrate will contain one or more diluents such as light carrier oils,
to facilitate handling and blending of the concentrate. Thus concentrates containing
up to about 50 wt. % of one or more diluents or solvents may be used, provided the
solvents are not present in amounts that interfere with the low and high temperature
and flash point characteristics and the performance of the finished power transmission
fluid composition. In this regard, the additive components used pursuant to this disclosure
may be selected and proportioned such that an additive concentrate or package formulated
from such components will have a flash point of about 170°C or above, using the ASTM
D-92 test procedure.
[0233] Such additive concentrates are suitably devoid of materials or components that are
bioaccumulative, toxic, and persistent as indicated by the tests described above.
Examples of such materials, include but are not limited to, certain alkanes, alkoxy
alkylamines, alkyl methacrylates, alkyl phenols, alkylphenols, polyoxyalkyl alkylamines,
aryl amines, aryl phosphites, branched alkyl phenols, branched alkyl polysulfides,
branched long-chain alkyl amines, long-chain alkenyl alkyl amine, long-chain alkenyl
alkylene amines, long-chain alkenyl amines, long-chain alkoxylated amines, long-chain
alkyl alkoxylated alcohols, long-chain alkyl alkylene amines, long-chain alkyl amines,
long-chain alkyl methacrylates, long-chain alkyoxylated amines, long-chain hydroxyalkyl
amines, polyaryls, and polyolefin polyamines.
[0234] Fuels and fuel additives of the embodiments herein may be formulated to provide enhanced
fuel and engine performance properties and/or improved low temperature viscometric
properties for various applications. A fuel composition according to the present disclosure
may be used for combustion in gasoline or diesel engines as well as stationary burners,
power plants, and home heating operations.
[0235] Fuels of the present disclosure may be used in various engine applications, including
but not limited to, internal combustion engines, rotary engines, gas turbine engines,
four-stroke engines, and two-stroke engines.
[0236] In one embodiment, a composition of the present disclosure may be manufactured in
the United States of America or Canada.
[0237] In a further embodiment, a composition of the present disclosure may be transported
to Europe by ship, air, rail, or truck.
[0238] At numerous places throughout this specification, reference has been made to a number
of U.S. Patents. All such cited documents are expressly incorporated in full into
this disclosure as if fully set forth herein.
[0239] Other embodiments of the present disclosure will be apparent to those skilled in
the art from consideration of the specification and practice of the embodiments disclosed
herein. As used throughout the specification and claims, "a" and/or "an" may refer
to one or more than one. Unless otherwise indicated, all numbers expressing quantities
of ingredients, properties such as molecular weight, percent, ratio, reaction conditions,
and so forth used in the specification and claims are to be understood as being modified
in all instances by the term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the specification and claims are approximations
that may vary depending upon the desired properties sought to be obtained by the present
invention. At the very least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each numerical parameter should
at least be construed in light of the number of reported significant digits and by
applying ordinary rounding techniques. Notwithstanding that the numerical ranges and
parameters setting forth the broad scope of the invention are approximations, the
numerical values set forth in the specific examples are reported as precisely as possible.
Any numerical value, however, inherently contains certain errors necessarily resulting
from the standard deviation found in their respective testing measurements. It is
intended that the specification and examples be considered as exemplary only, with
a true scope and spirit of the invention being indicated by the following claims.
[0240] The foregoing embodiments are susceptible to considerable variation in practice.
Accordingly, the embodiments are not intended to be limited to the specific exemplifications
set forth hereinabove. Rather, the foregoing embodiments are within the spirit and
scope of the appended claims, including the equivalents thereof available as a matter
of law.
[0241] The patentees do not intend to dedicate any disclosed embodiments to the public,
and to the extent any disclosed modifications or alterations may not literally fall
within the scope of the claims, they are considered to be part hereof under the doctrine
of equivalents.
The invention also relates to the following numbered embodiments:
- 1. An environmentally compatible fuel additive composition comprising four or more
functional components, wherein each component is selected from the group consisting
of a non-persistent material, a non-bioaccumulative material, and a non-toxic material,
and the additive composition is devoid of components that are persistent, bioaccumulative,
and toxic.
- 2. The fuel additive composition of embodiment 1, wherein the functional components
comprise materials selected from the group consisting of: an antifoam agent, an anti-icing
additive, an antiknock additive, an antioxidant, an antistatic additive, an anti-valve-seat
recession additive, an antiwear agent, a biocide, a carrier fluid, a cetane improver,
a combustion improver, a compatibilizer, a conductivity improver, a corrosion inhibitor,
a dehazer, a demulsifier, a detergent, a dispersant, a drag reducing agent, a dye,
an emulsifier, a foam inhibitor, a friction modifier, a fuel stabilizer, an injector
deposit control additive, a lubricity additive, a marker or customer-specific "tag",
a metal deactivator, an octane improver, a pour point depressant, a reodorant, a seal
swell additive, a surfactant, and a wax anti-settling additive (a "WASA").
- 3. The fuel additive composition of embodiment 1, wherein the non-persistent material
is determined by a biodegradation test selected from the group consisting of a dissolved
organic carbon die-away test, a modified OECD screening dissolved organic carbon die-away
test, a carbon dioxide evolution test, a manometric respirometry test, a closed bottle
test, a MITI test, a Zahn-Wellens test, an activated sludge simulation test, an activated
sludge respiration inhibition test, and a modified SCAS test.
- 4. The fuel additive composition of embodiment 1, wherein the non-bioaccumulative
material is determined by a bioconcentration factor test comprising a flow-through
fish test.
- 5. The fuel additive composition of embodiment 1, wherein the non-bioaccumulative
material has bioconcentration factor test result below 2000.
- 6. The fuel additive composition of embodiment 1, wherein the non-toxic material is
determined by a toxicity test selected from the group consisting of an acute toxicity
for fish test, an acute toxicity for Daphnia test, and an algal inhibition test.
- 7. The fuel additive composition of embodiment 1, wherein the non-toxic material is
devoid of a toxic effect at an aqueous concentration below 0.01 mg/L on a toxicity
test.
- 8. The fuel additive composition of embodiment 1, wherein a non-persistent material
is a material having an acceptable score on a biodegradation test selected from at
least one of the following:
- a) a half-life in marine water is less than 60 days;
- b) a half-life in fresh or estuarine water is less than 40 days;
- c) a half-life in marine sediment is less than 180 days;
- d) a half-life in fresh or estuarine water sediment less than 120 days; or
- e) a half-life in soil less than 120 days.
- 9. The fuel additive composition of embodiment 1, wherein at least one of the components
is selected from the group consisting of: a sulfurized neopentyl glycol phosphate,
a substituted succinimide, a reaction product of a C16 alkyl dicarboxylic acid and ammonia, a fatty amine ethoxylate, an oleamide, and a
dodecyl succinic acid.
- 10. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a pour point depressant.
- 11. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a combustion improver.
- 12. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a foam inhibitor.
- 13. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a cetane number improver.
- 14. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises an adipate.
- 15. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a sulfurized isobutylene.
- 16. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises an alkylthiadiazole.
- 17. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises an alkylpolymethacrylate comprising less than 0.3% weight of unreacted monomer.
- 18. The fuel additive composition of embodiment 1, wherein at least one of the components,
comprises an olefin copolymer or a multifunctional olefin copolymer viscosity index
improver comprising less than 0.3% weight of unreacted monomer.
- 19. The fuel additive composition of embodiment 1, wherein at least one of the components
comprises a polyalphaolefin.
- 20. The fuel additive composition of embodiment 1, wherein the additive is useful
in gasoline compositions.
- 21. The fuel additive composition of embodiment 1, wherein the additive is useful
in diesel fuel compositions.
- 22. The fuel additive composition of embodiment 1, wherein said composition is transported
to any site within Europe by a method selected from ship, air, rail, and truck.
- 23. The fuel additive composition of embodiment 1, wherein said composition is manufactured
in the USA or Canada.
- 24. An environmentally compatible fuel composition, comprising:
- a) a major amount of a fuel; and
- b) a minor amount of an additive composition, comprising four or more functional components,
wherein each component comprises at least one of: an acceptable level of biodegradation
as determined by a biodegradation test, a bioconcentration factor below 2000, or is
devoid of a toxic effect at an aqueous concentration below 0.01 mg/L an a toxicity
test.
- 25. The fuel composition of embodiment 24, wherein the functional components comprise
materials selected from the group consisting of: an antifoam agent, an anti-icing
additive, an antiknock additive, an antioxidant, an antistatic additive, an anti-valve-seat
recession additive, an antiwear agent, a biocide, a carrier fluid, a cetane improver,
a combustion improver, a compatibilizer, a conductivity improver, a corrosion inhibitor,
a dehazer, a demulsifier, a detergent, a dispersant, a drag reducing agent, a dye,
an emulsifier, a foam inhibitor, a friction modifier, a fuel stabilizer, an injector
deposit control additive, a lubricity additive, a marker or customer-specific "tag",
a metal deactivator, an octane improver, a pour point depressant, a reodorant, a seal
swell additive, a surfactant, and a wax anti-settling additive (a "WASA").
- 26. The fuel composition of embodiment 24, wherein the biodegradation test is selected
from the group consisting of a dissolved organic carbon die-away test, a modified
OECD screening dissolved organic carbon die-away test, a carbon dioxide evolution
test, a manometric respirometry test, a closed bottle test, a MITI test, a Zahn-Wellens
test, an activated sludge simulation test, an activated sludge respiration inhibition
test, and a modified SCAS test.
- 27. The fuel composition of embodiment 24, wherein the bioconcentration factor test
comprises a flow through fish test.
- 28. The fuel composition of embodiment 24, wherein the toxicity test is selected from
the group consisting of an acute toxicity for fish test, an acute toxicity for Daphnia test, and an algal inhibition test.
- 29. The fuel composition of embodiment 24, wherein the acceptable score on a biodegradation
test comprises at least one of the following:
- a) a half-life in marine water is less than 60 days;
- b) a half-life in fresh or estuarine water is less than 40 days;
- c) a half-life in marine sediment is less than 180 days;
- d) a half-life in fresh or estuarine water sediment less than 120 days; or
- e) a half-life in soil less than 120 days.
- 30. The fuel composition of embodiment 24, wherein the fuel is selected from the group
consisting of one or more of gasoline, diesel fuel, middle distillate fuel, biodiesel
fuel, an alcohol, such as but not limited to an ethanol, bioethanol, a biobutanol,
an aviation fuel, jet fuel, marine fuel, bunker fuel, burner fuel, home heating oil,
a gas-to-liquid (GTL) base oil, a Group I base oil, a Group II base oil, a Group III
base oil, a Group IV base oil, an ester, a vegetable oil, and mixtures thereof.
- 31. A method of making an environmentally compatible fuel composition, comprising
combining a major amount of a fuel and a minor amount of an additive composition,
comprising four or more functional components, wherein each component is selected
from: a material having an acceptable level of biodegradation, a material having a
bioconcentration factor below 2000, and a material that is devoid of a toxic effect
at an aqueous concentration below 0.01 mg/L on a toxicity test, wherein the fuel composition
complies with European Council Directive 67/548/EEC.
- 32. The method of embodiment 31, wherein the functional component further comprises
a material selected from the group consisting of: an antifoam agent, an anti-icing
additive, an antiknock additive, an antioxidant, an antistatic additive, an anti-valve-seat
recession additive, an antiwear agent, a biocide, a carrier fluid, a cetane improver,
a combustion improver, a compatibilizer, a conductivity improver, a corrosion inhibitor,
a dehazer, a demulsifier, a detergent, a dispersant, a drag reducing agent, a dye,
an emulsifier, a foam inhibitor, a friction modifier, a fuel stabilizer, an injector
deposit control additive, a lubricity additive, a marker or customer-specific "tag",
a metal deactivator, an octane improver, a pour point depressant, a reodorant, a seal
swell additive, a surfactant, and a wax anti-settling additive (a "WASA").
- 33. The method of embodiment 31, wherein the biodegradation test is selected from
the group consisting of a dissolved organic carbon die-away test, a modified OECD
screening dissolved organic carbon die-away test, a carbon dioxide evolution test,
a manometric respirometry test, a closed bottle test, a MITI test, a Zahn-Wellens
test, an activated sludge simulation test, an activated sludge, respiration inhibition
test, and a modified SCAS test.
- 34. The method of embodiment 31, wherein the bioconcentration factor test comprises
a flow-through fish test.
- 35. The method of embodiment 31, wherein the toxicity test is selected from the group
consisting of an acute toxicity for fish test, an acute toxicity for Daphnia test, and an algal inhibition test.
- 36. The method of embodiment 31, wherein the acceptable score an a biodegradation
test comprises at least one of the following:
- a) a half-life in marine water is less than 60 days;
- b) a half-life in fresh or estuarine water is less than 40 days;
- c) a half-life in marine sediment is less than 180 days;
- d) a half-life in fresh or estuarine water sediment less than 120 days; or
- e) a half-life in soil less than 120 days.
- 37. An environmentally compatible fuel composition comprising:
- a) a major amount of a fuel; and
- b) a minor amount of an additive composition, comprising four or more functional components,
wherein each component is selected from the group consisting of non-persistent materials,
non-bioaccumulative materials and non-toxic materials, and the additive composition
is devoid of components that are persistent, bioaccumulative, and toxic.
- 38. The fuel composition of embodiment 37, wherein the functional components comprise
materials selected from the group consisting of: an antifoam agent, an anti-icing
additive, an antiknock additive, an antioxidant, an antistatic additive, an anti-valve-seat
recession additive, an antiwear agent, a biocide, a carrier fluid, a cetane improver,
a combustion improver, a compatibilizer, a conductivity improver, a corrosion inhibitor,
a dehazer, a demulsifier, a detergent, a dispersant, a drag reducing agent, a dye,
an emulsifier, a foam inhibitor, a friction modifier, a fuel stabilizer, an injector
deposit control additive, a lubricity additive, a marker or customer-specific "tag",
a metal deactivator, an octane improver, a pour point depressant, a reodorant, a seal
swell additive, a surfactant, and a wax anti-settling additive (a "WASA").
- 39. A method of fueling an engine comprising supplying to an engine a fuel composition
of embodiment 37.
- 40. The method of embodiment 39, wherein said engine is a spark-ignition engine.
- 41. The method of embodiment 39, wherein said engine is a compression ignition engine.
- 42. The method of embodiment 39, wherein said engine is selected from the group consisting
of an internal combustion engine, a rotary engine, a gas turbine engine, a four-stroke
engine, a two-stroke engine, and an outboard motor engine.