Note: Descriptions are shown in the official language in which they were submitted.
PCT/El'91 /00988
WO 91/18961
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This invention relates to the use of reodorants in liquid
petroleum fuels, for example middle distillate fuels such as
heating oils.
Middle distillates are fuels obtained in the refining of
crude oil as the fraction between the lighter kerosene and
jet fuels fraction and the heavy fuel oil fraction. They are
typically used as diesel fuel and heating oil. A problem
with a middle distillate fuel is its odour which, depending
on the source of the oil, may range from acceptable to
totally unacceptable to those in the vicinity of th~a oil such
as the user. There is therefore a need to provide 'ways of
reducing or neutralising the odour of such oils.
It is known to incorporate esters into fuel oils. For
example, US-A-4 353 710 describes adding ester fuel extenders
to hydrocarbon fuels heavier than gasoline. Also,
GH-A-2 115 004 describes an additive composition for
hydrocarbon fuels comprising a mixture that includes an
aliphatic C1_6 ester, the additive being for improving fuel
efficiency and providing cleaner burning.
The invention is concerned with use of reodorant additives
for oils such as the abave, the additives being or including
esters and being, if desired, used with synergistic effect in
combination with perf~e oils and without disadvantageous
effect in combination with components commonly used as
additives to heating oils such as combustion improvers and
metal deactivators.
The invention provides, in a first aspect, the use in a
liquid petroleum fuel of an additive comprising a
first-mentioned ester that is soluble in the fuel, ~:he ester
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having up to 25 carbon atoms and being of a carboxylic acid
and an alcohol, wherein the additive masks or reduces the
odour of the fuel oil.
The finding that the afore-mentioned ester is capable of
masking or reducing the odour of the fuel oil is surprising
because the odour of the latter is generated by the effect of
many components. Thus, one would not expect to be able to
mask or reduce a fuel oil odour using an ester according to
this invention.
If desired, the ester may be used in admixture with a pearfume
oil, comprising one or more aldehydes, ketones, alcohols and
esters, and possibly terpenes wherein any ester in the
perfume oil is different from the first-mentioned ester. The
concentration of ester and perfume oil together in the fuel
required to produce a particular reodorant effect may be much
less than the concentration of either ester or perfume oil
alone in the fuel required to produce a similar reodorant
effect, i.e. the ester and perfume oil may act
synergistically.
The findings of this invention can be economically
significant when the perfume oil is much more expensive than
the ester. Thus, the cost of materials to produce a given
reodorant effect would, using this invention, then be lower
than when a perfume oil were used as sole reodorant.
In a second aspect, this invention provides a fuel comprising
in admixture a major proportion of a liquid petroleum fuel
and a minor proportion of a readorant additive comprising a
first-mentioned ester that is soluble in the fuel and having
up to 25 carbon atoms and being of a carboxylic acid and an
alcohol, in admixture with a perfume oil comprising one or
more aldehydes, ketones, alcohols and esters wherein any
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ester in the perfume oil is different from the
first-mentioned ester.
The first-mentioned ester in this invention has, as stated
above, up to 25 carbon atoms. Preferably it has up to 20
carbon atoms such as 4 to 14, in particular, 6 to 12 carbon
atoms. The carboxylic acid, which preferably has from 1 to 4
carbon atoms, may for example be a saturated aliphatic
monocarboxylic acid. The alcohol, which preferably has from
3 or 4 to ZO carbon atoms, may for example be a saturated
aliphatic monohydric alcohol. Preferred esters are C4_ZO
alkyl esters of acetic acid. Single esters or mixtures
thereof may be used such as n-heptyl acetate or an
equimolecular mixture of n-hexyl acetate and n-octylacetate.
The esters, which may be known in the art, may for example be
made by reacting a carboxylic acid with the appropriate
alcohol.
By "perfume oil" in this specification is any substance,
other than the first-mentioned ester, having an odour that is
capable, when used alone, of masking an odour of a liquid
petroleum fuel to be treated. The perfume oil does not
necessarily impart a sweet or pleasant odour to the fuel. As
stated above, such an oil may comprise one or more of
aldehydes, ketones, esters and alcohols. It may, for example
be a blend including all of the above and may contain other
constituents such as organo-nitrogen compounds, lactones,
ethers (including acetals and ketals), hydrocarbon, and
other organic materials. Perfume ails may for example be
proprietary blends. Examples of perfume oils are proprietary
blends produced by Bush, Boake and Allen and other
praprietary fumes.
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In the practice of the invention, the fuel may be any liquid
petroleum product between LPG and heavy fuel oil, for example
boiling in the range of 100'C to 500'C (e.g. 150'C to
400'C). It is preferably a diesel oil or~ a heating oil, a
diesel oil being a middle distillate fuel such as according
to an ASTM Specification and a heating oil being a middle
distillate fuel far use in space heating, for example
according to ASTM Specification D-396-80. It may, if
desired, include other components such as a combustion
improver or a metal deactivator or both, examples of which
are known in the art. Further, a flow improver such as known
in the art may also be included.
A combustion improver is a compound such as an arganometallic
compound which, in use of a heating oil, supports combustion
of a heating oil droplet by releasing chemically active metal
at the flame temperature. In this way, a catalytic surface
is provided to still unburnt hydrocarbons resulting in higher
conversion of generated soot. An example of such combustion
improvers are organometallic sandwich compounds such as
dicyclopentadienyliron, commonly known as ferrocene, wherein
each of the cyclopentadiene rings may be unsubstituted or may
be independently substituted with one or more alkyl,
cycloalkyl, aryl or heterocyclic groups.
A metal deactivator is a component for deactivating metals
which would otherwise cause the oil to deteriorate over a
period of storage. Such deterioration, which is of unstable
materials such as unsaturated hydrocarbons in the oil, may
result in sediments and gums being formed which, in use of
the oil in a heating installation, affect overall performance
by blocking fuel falters and, when deposited in the burner
nozzle, by disturbing the fuel spray pattern. A cause of
such deterioration is the presence of copper arising from its
use as a construction material in heating installations; such
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copper catalyses the deterioration processes. An example of
a metal deactivator is a compound containing secondary amine
functionality, allowing circulation of metal ions, and
sufficiently large hydrophobic side chains) to provide
solubility in the fuel. A specific example is ~iannich
condensation product in the form of an alkylated phenol
having a secondary amine side chain.
Examples of flow improvers known in the art are
ethylene/vinyl ester copolymers, fumarate/vinyl ester
copolymers, phthalic acid derivatives, ethylene propionates
and terpolymers including ethylene and vinyl esters.
If desired, the fuel may include further components. Some
examples are dispersants and detergents such as a
polyisobutylene succinic anhydride polyamine blend known in
the art, and macrocyclic compounds such as described in
US-A-4,637,886 and US-A-4,880,923.
The ester, or ester and perfume oil, may be provided in the
fuel by addition thereto of a concentrate including the
ester, or ester and perfume oil. In a third aspect, the
invention provides a reodorant concentrate for addition to a
liquid petroleum fuel comprising, in admixture in solution in
a solvent therefor, a first-mentioned ester that is soluble
in the fuel and having up to 25 carbon atoms and being of a
carboxylic acid and an alcohol, in admixture with a perfume
oil comprising one or more aldehydes, ketones, alcohols and
esters Wherein any ester in the perfume oil is different from
the first-mentioned ester. The solvent must be compatible
with the fuel; examples are aromatic solvents such as those
with an average C number of 9.
WO 91!I8961 PCTlEP91/00988
The concentrate may include other components, for example a
combustion improver, a metal deactivator, a flow improver, or
a dispersant/detergent such as described above. As an
exemplary generalisation, the composition of the concentrate
may fall within the following ranges where the percentages
are weight/weight:ester (1-25%), perfume ail (0.5-25%),
combustion improver (1-50%), metal deactivator (2-25%), and
solvent (25-80%).
In all aspects of the invention where the perfume oil is
present, the relative proportions of ester and perfume oil
may be significant. Thus, the ratio of ester and oil (weight
of ester: weight of oil) may be in the range of 1:20 to 20:1,
e.g. 5:1 to 20:1. In the first and second aspects where the
perfume oil is present the total proportion of ester and
perfume oil together may, for example, be up to 500 ppm
(weight:weight), such as 5 ppm to 200 ppm, for example 25 ppm
to 200 ppm:
The following are examples of the invention.
preparation of Concentrate
The following components were mixed together in the
proportions indicated where all percentages are
weight: weight. Proprietary names and/or sources may be given
in parentheses.
Ester . n-heptyl acetate; V.P. 0.5 kPa at 38'C
(9.6%).
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WO 91118961 PCTlEP91/00988
Perfume Oil . a proprietazy perfume oil comprising a
mixture including one or more aldehydes,
alcohols and esters (1.2~%)
(ex Eush Baake~ and ,Allen; Reference 11598).
Combustion . ferrocene (3.66%)
Improver (ex Pluto)
Metal . alkylated phenol with secondary amine side
Deactivator chain (10%).
Solvent . aromatic liquid of average C number 9
(75.54%).
U,se of Concentrate
The above-prepared concentrate (11) was added to a heating
oil (2000 1) having an unpleasant odour and thoroughly
admixed therewith by shaking to give 500 ppm of the
concentrate in the oil, i.e. 48 ppm of ester and 6 ppm of
perfume oil.
Samples of the above-treated heating oil were placed in
containers and rated for odour by six people independently on
each of five successive days at the same time each day, the
containers being kept closed between ratings. Each of the
people rated the odour on a scale of 1 to 6 on each of the
dayss 3 represents a neutral odours greater than 3 represents
an unpleasant odour where a higher number represents a more
unpleasant odour: and less than 3 represents a pleasant odour
where a lower number represents a more pleasant odour. The
average rating was between 2 and 3, showing that the
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concentrate had completely masked the original unpleasant
odour of the heating oil.
The procedure of Example I was repeated with the exception
that the perfume oil was a proprietary oil designated as
BBA 11597 (ex Bush Boake and Allen) and the heating oil
contained, after treatment, 30 ppm of the ester and 6 ppm of
the perfume oil.
The average rankings for odour were:
DAY: 1 2 3 4 5
RANK: 2~ 2~ 2~ 2~ 2~
amg,a~e 3
The procedure of Example 2 was repeated with the exception
that the perfume oil was a proprietary oil designated as
BBA 11622 (ex Bush Boake and Allen).
The average rankings for odour were:
DAY: 1 2 3 4 5
RANK: 2 2 2s 2 2
~xaalple 4
The procedure of Example 2 was repeated with the exception '
that the perfume oil was a proprietary oil designated as
BBA 11621 (ex Bush Boake and Allen).
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The average rankings for odour were:
DAY: 1 2 3 ~ 5
RANK: 3~ 2~ 3 2 2
The above results illustrate the effectiveness of the
present invention in masking or rendering pleasant the
original unpleasant odour of the heating oil. In each
example the perfume oil and ester were each independentl~r
unable to mask the original unpleasant smell of the heating
oil at the stated concentrations.
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