MIXTURE OF SYMMETRICAL AND ASYMMETRICAL
POLYOXYMETHYLENE DIALKYLETHERS AND THEIR USE IN
HYDROCARBON DISTILLATES.
The invention relates to the use of organic compounds of the
polyoxymethylene dialkylethers type as a component in hydrocarbon distillates in
particular gas oils.
The invention also relates to compositions comprising mixtures of organic
compounds of the symmetrical polyoxymethylene dialkylethers type and their
combination with asymmetrical polyoxymethylene dialkylethers, as well as
hydrocarbon distillates containing these compositions.
The oil industry has for a long time been endeavouring to develop new motor
fuels that encourage the reduction of pollutant emissions from engines.
Moreover, environmental pressures are driving this reduction of pollutant
emissions in particular those from automobile engines as well as the switch from
fossil energy to energy from renewable sources. Industrial companies are thus
increasingly using ethanol originating from wheat, sugar-beet or sugar cane products
as a component of or even a substitute for motor fuels of fossil origin.
Recent developments in this field have delivered oxygenated compounds
originating from systems that upgrade alcohols such as methanol or ethanol and/or
formol. These systems deliver, through oligomerization of the alcohols with formol,
derivatives of the polyoxyalkylene type with a terminal alkoxy group which present
useful characteristics, in particular a high cetane number, the absence of sulphur,
aromatics and a C-C bond, which overall furthers a non-pollutant combustion
avoiding in particular the emission of particles.
These derivatives of the polyoxyalkylene type with a terminal alkoxy group
can be used either as a component in hydrocarbon distillates from the refining of
hydrocarbon sources of fossil origin or as a substitute for these.
Thus, patent EP 1070755 describes a liquid mixture comprising a diesel fuel
and 1 to 20% by volume of one or more oxygenated compounds of formula R-(O-
CH2)m-O-R where R is an alkyl chain CnH2+1, m is an integer from 2 to 6 and n an
integer from 1 to 10. The described process necessarily leads to mixtures of
symmetrical compounds, the nature of the 2 alkyl chains R being identical, but only
the number of oxymethylene units of which varies. It is noted that the cetane number
and the % of oxygen of this motor fuel composition are increased in a surprising
way. EP 1422285 discloses that these same compounds are used as a motor fuel
substitute for diesel engines in order to encourage the reduction of the emission of
pollutant particles.

US 6350919 also describes a preparation process leading principally to
symmetrical compounds of the polyoxymethylene diethylether type or to
symmetrical compounds of the polyoxymethylene dimethyl ether type.
There is therefore a need to provide novel motor fuel compositions which
encourage the reduction of pollutant emissions from engines and which also
encourage the switch from fossil energy to energy from renewable sources.
One of the routes chosen by the Applicant is that of the incorporation of
mixtures of different symmetrical polyoxymethylene dialkylethers, or their
combination with asymmetrical polyoxymethylene dialkylethers, as a component in
gas oils for diesel engines.
To this end, the present invention proposes a composition comprising:
a) a mixture of at least one compound An of formula X-(O-CH2)n-O-X in
which n represents an integer from 1 to 5 where X is represented by the formula
CzH2z+1 in which z is an integer from 1 to 10, with at least one compound A'n' of
formula X'-(O-CH2)n'-O-X' in which n' represents an integer from 1 to 5, where X'
is represented by the formula CzH2z+1 in which z is an integer from 1 to 10, a mixture
in which An and AV are different from each other, X and X' are different from each
other;
or
b) a mixture comprising the compounds An and AV described above
with at least one compound Bm of formula X-(O-CH2)m-O-X' in which m represents
an integer from 1 to 5, X and X' are different from each other and X and X' are
represented by the formula CzH2z+1 in which z is an integer from 1 to 10.
In these definitions, it is understood that for each type of compound An, AV or
Bm the values of z, n, n', m vary independently from each other. Preferably, z is an
integer ranging from 1 to 4, or also from 1 to 2.
Moreover, compounds are preferred where, when z = 1 or 2 in the formula of
the group X or X' then n, n' or m range from 2 to 4, or the compounds where, when z
= 3 then n, n' or m range from 1 to 3.
According to a particular embodiment, the invention relates to compounds
where n, n' and m represent independently an integer from 2 to 5, preferably 2 to 4,
or also to compounds in which X represents the CH3 group and X' represents the
C2H5 group.
According to the results of work carried out by the Applicant, when
polyoxymethylene compounds of formula A or A' with a terminal methoxy group
(called POM/MM in which to X is CH3) or with a terminal ethoxy group (called
POM/EE in which X' is C2H5), crude or non-distilled with n or n' being an integer
from 3 to 8, are incorporated in gas oils at levels greater than or equal to 3.5%, these

do not allow these compositions to retain acceptable properties conforming to the
specifications for use, in particular the properties of limpidity of the distillate,
resistance to low temperatures and the blocking tendency of the distillate. These
compounds cause the deterioration of the cold filter plugging point (CFPP) of the
compositions of final distillates by more than 5°C, a change in their appearance in
particular the formation of a haze, and an increase in their blocking tendency in a
proportion of more of 20%.
Surprisingly, the compositions according to the invention allow final
compositions of distillates to be obtained, of which the appearance, the CFPP and the
rate of blocking are kept at values that conform to the specifications of use for
commercial fuels and motor fuels. In particular when the compositions according to
the invention are used at levels below 20%, preferably below 10%, or also at levels
of 1 to 7% in the distillate as diesel fuels, it is seen that the variation of the CFPP is,
in absolute values, less than 5°C i.e. the increase in the CFPP is at most 5°C.
Moreover, it is also seen that the variation in the blocking tendency is less than
20%. These results are wholly unexpected bearing in mind the results obtained with
the polyoxymethylene compounds of the prior art.
The invention relates more specifically to compositions comprising a mixture
of the compounds An and A'n- in which An is present in proportions by mass ranging
from 1 to 99% or from 10% to 90% and AY is present in proportions by mass from
99% to 1% or from 90% to 10% in the total composition, An is preferably present at
from 25% to 75% and AY is present at from 75% to 25%, more preferably An is
present at from 45 to 55% and A'n- is present at from 55 to 45%.
Preferably these compositions comprise 50% to 75% of compounds AY where
X' represents the C2H 5 group and 25% to 50% of An or X represents the CH3 group.
The invention also relates to compositions comprising a mixture of compounds
of formula An, A'n- and Bm in which X represents the CH3 group, X' represents the
C2H5 a group and n, n' and m represent independently an integer from 1 to 5, a
mixture in which An, A'n' and Bm are independently present in ranges by weight from
1 to 40 % by mass for An, from 20 to 50% by mass for Bm and from 10 to 90 % by
mass for AY, the total of the % making 100%.
More particularly the compositions according to the invention comprise more
than 60% by mass of compounds where n, n' or m range independently from 2 to 5.
Finally, the compositions according to the invention are preferred in which n,
n' and m represent independently an integer from 2 to 4 when z is less than or equal
to 2 in the formula of the group X or X' and which comprise 60 to 95% by mass of
compounds where n, n' or m range from 3 to 4. Moreover, the compositions are also

preferred in which n, n' or m range from 1 to 3, when z = 3 and which comprise
more than 50 % by mass of compounds, where n, n' or m range from 1 to 3 .
According to another object, the invention relates to a hydrocarbon distillate
comprising a composition of a mixture of polyoxymethylene dialkylethers as
described above in a proportion by mass that does not worsen the CFPP measured
according to the standard NF EN116 by more of 5°C and produces a deterioration of
the blocking tendency as measured according to the standard IP 387 of less than
20%.
This hydrocarbon distillate advantageously comprises a proportion by volume
less than or equal to 20%, preferably less than or equal to 10%, preferably from 1 to
10% of a composition of a mixture of polyoxymethylene dialkylethers as described
above.
The distillates comprise at least one hydrocarbon cut originating from the
group constituted by distillates with a boiling point comprised between 150 and
450°C comprising the direct distillation distillates, vacuum distillates, hydrotreated
distillates, distillates originating from catalytic cracking and/or hydrocracking of
distillates under vacuum, diesel fuels, distillates resulting from conversion processes
of the ARDS (atmospheric residue desulphurization) type and/or viscoreduction,
distillates originating from the upgrading of Fischer Tropsch cuts, distillates resulting
from the conversion of plant and/or animal biomass, taken alone or in combination,
and plant and animal oils, their hybrids, genetically modified species and the esters
of these oils, hydrogenated or not, taken alone or in combination.
Moreover, additives chosen from detergents, dispersants, de-emulsifiers, anti-
foaming agents, biocides, reodorants, cetane improvers, anti-corrosion agents,
antioxidants, friction modifiers, lubricity, combustion, cloud point, flow point, anti-
sedimentation and conductivity modifiers can be added to hydrocarbon distillates .
According to a preferred embodiment, the invention relates to a diesel fuel
comprising from 1 to 20% by volume of a composition of a mixture of
polyoxymethylene dialkylethers as described above and a lubricity agent.
According to another object, the invention relates to the use of a composition
of a mixture of polyoxymethylene dialkylethers as described above in a hydrocarbon
distillate, preferably a diesel fuel.
According to an embodiment, the % of the composition of the mixture of
polyoxymethylene dialkylethers in the diesel fuel is less than or equal to 20%,
preferably from 1 to 10%.
According to another object, the invention relates to the use of a composition
of a mixture of polyoxymethylene dialkylethers as described above alone, as a
substitute for a hydrocarbon distillate or as an motor fuel.

According to another object, the invention relates to the use of a composition
of a mixture of polyoxymethylene dialkylethers as described above in a mixture with
the distillates resulting from the conversion of plant or animal biomass as a fuel or
motor fuel.
The symmetrical polyoxymethylenes of formula An or AVwhere An is defined
by the formula X-(O-CH2)n-O-X and A'n' is defined by the formula X'-(O-CH2)n-O-
X' in which X and X' represent the formula CZH2Z +1 in which z is an integer from 1
to 10, n and n' represent independently an integer from 1 to 5, are prepared by acid
catalysis, preferably in the presence of an acid resin, from trioxane and an acetal of
formula XO-CH2-OX or X'0-CH2-OX'.
The process is generally carried out without solvent at a temperature comprised
for example between 20 and 80°C, preferably 40-50°C.
The trioxane (considered in formaldehyde equivalent)/acetal molar ratio is in
general from 0.5 to 1, preferably 0.75. The acid resin used is typically Amberlyst
A15, at a level comprised between 0.5 and 10% by weight relative to the reaction
mixture, preferably of the order of 5%.
The reaction leads to a mixture of compounds An of formula X-(OCH2)n-OX or
of compounds AV of formula X'-(O-CH2)n-O-X' where n and n' range
independently from 1 to 8. The distribution by mass of the different fractions is
determined by gas chromatography (GC).
The different compounds can then be isolated separately or in a mixture in the
form of distillation cuts obtained by distillation or evaporation under reduced
pressure.
Thus, in order to obtain the compositions of symmetrical polyoxymethylenes
according to the invention, the fractions of compounds where n, n' range
independently from 1 to 5 and preferably where n, n' range independently from 3 to
5 or also from 3 to 4 are isolated.
According to a particular version, when methylal is used as acetal, compounds
of POM/MM type are obtained where X is the methyl group CH3. When ethylal is
used as acetal, compounds of POM/EE type are obtained where X' is the ethyl group
C2H5.
Thus, the fractions of POM/EE or POM/MM compounds where n and n' range
independently from 2 to 5 or also from 3 to 4 are preferably isolated.
The mixtures containing the combinations of symmetrical and asymmetrical
POMs are prepared according to the same process from a mixture of different acetals
and trioxane.
Typically the reaction of 2 different acetals XO-CH2-OX and X'0-CH2-OX'
(in molar ratios that can vary between 1/99 and 99/1, preferably ranging from 75/25

to 25/75 or also in a molar ratio of 50/50) with the trioxane leads to a mixture of
symmetrical POMs An and AY of formula X-(OCH2)n-OX and X'-(OCH2)n-OX'
and of asymmetrical POMs Bm of formula X-(OCH2)m-OX' in which n, n' and m
range independently from 2 to 8.
In the same way, the different compounds of the mixture can be isolated
separately or in the form of cuts by distillation under reduced pressure. Thus in order
to obtain the compositions comprising the compounds A„, AY and Bm according to
the invention, the fractions of compounds where n, n' and m range independently
from 2 to 5 and preferably where n, n' and m range independently from 2 to 4 are
isolated.
According to a particular version, when a mixture of acetals such as methylal
and ethylal is preferably used, a mixture of POM/MM, POM/EE and POM/ME is
obtained and these different compounds can be isolated separately or in the form of
cuts by distillation under reduced pressure.
According to a preferred embodiment, the ternary mixture POM/MM,
POM/EE and POM/ME is prepared according to the process described above using
an ethylal/ methylal molar ratio ranging from 75/25 to 25/75 through the ratio 50/50.
Then, in order to obtain the compositions according to the invention, the fractions of
the mixture in which n, n' and m range independently from 2 to 5 or range from 2 to
4 are isolated.
Thus, in these different preparation processes and in order to obtain the
compositions according to the invention, the compounds or the mixtures of
compounds in which n, n' or m range independently from 1 to 5 are isolated. This
separation is carried out generally by distillation under temperature and pressure
conditions within the scope of a person skilled in the art and which allow the
elimination of the heavy fractions where n, n' or m is plainly greater than 5. The
distribution by mass of the different fractions, as determined by GC, shows that the
% of these heavy fractions is less than or equal to 10%.
Then, to prepare the compositions according to the invention intended to be
incorporated in gas oils, in particular the mixtures of symmetrical compounds An and
AY of the invention, a composition An is mixed at a temperature of about 25°C with
a composition AY in a proportion by mass in the total composition ranging from 1 to
99% or 10% to 90% for An and 99% to 1% or 90% to 10% for AY, or ranging from
25% to 75% for A and from 75% to 25% for A' or also with 45% to 55% or 50% of
An and 55% to 45% or 50% of AY.
According to a preferred embodiment, a proportion of symmetrical POMs
POM/EE [of formula X'-(OCH2)n-OX' where X' is Et] greater than that of
symmetrical POMs POM/MM [of formula X-(OCH2)n-OX where X is Me] is used,

and for example a composition is used with a proportion ranging from 50% to 75%
of POM/EE and a proportion ranging from 25% to 50% of POM/MM.
This embodiment presents the advantage of using the ethanol directly as a
source of energy originating from biomass and proposing it in a modified form that is
easily accessible (in the form of POM). More over, this form is more easily handled
at an industrial level and proves to be more compatible with motor fuels than ethanol
in itself. In fact, in particular as regards the boiling points, those of the POMs are
higher than that of ethanol and, as regards solubility in hydrocarbons, the POMs are
more soluble than ethanol itself.
According to another embodiment, the invention relates to the compositions
comprising a ternary mixture, i.e. a mixture of the compounds of formula An and A'n-
and Bm, An, A'n- and Bm being as defined above and in which n, n' and m range
independently from 1 to 5, preferably where n, n' and m range independently from 2
to 5 or also from 2 to 4.
According to a preferred embodiment, the composition is a ternary mixture
POM/MM, POM/EE and POM/ME of compounds in which n, n', m range
independently from 2 to 5, the mixture being prepared according to the process
described above using an ethylal/ methylal molar ratio ranging from 75/25 to 25/75.
According to another embodiment, the different compositions according to the
invention do not contain compounds where n, n', m is less than 2. In fact the
elimination of the volatile fractions of the components of the invention the boiling
point of which is below the initial boiling point of the distillate in which they are
incorporated allows the flash point of the final distillate to be kept within ranges that
conform to the specifications of use of motor fuels.
According to a preferred embodiment, this ternary mixture comprises, by mass,
1% to 40% of compound A„, 20% to 50% of compound Bm and 10% to 90% of
compound A'n-, in which n, n', m range independently from 2 to 4. This mixture is
prepared according to the process described above using an ethylal/methylal molar
ratio of 75/25 and eliminating the fractions where n, n', m are less than 2 and more
than 5. Furthermore and in order to maintain or improve the properties of the final
compositions of distillates compared with the values of the specifications of use for
commercial motor and other fuels, compositions according to the invention are
preferred where n, n', m is an integer which ranges from 2 to 5 or more preferably
which ranges from 3 to 4.
Generally, the compositions according to the invention comprise more than
60% by mass of compounds where n, n' or m range independently from 2 to 5 and
more particularly when, in the compositions, n, n' or m is an integer ranging from 2

to 4, these comprise, by mass, a majority of the compounds where n, n' or m range
independently from 3 to 4.
For example, compositions according to the invention in which n, n' and m
represent independently an integer from 2 to 4 and comprise from 60 to 95% by mass
of compounds where n, n' and m range from 3 to 4 are preferred.
The invention also relates to a motor or other fuel and/or fuel oil containing
from 1% to 100% of a composition according to the invention.
The invention also relates particularly to a fuel, for example a motor fuel
and/or a fuel oil containing a major part corresponding to more than 80% of a
hydrocarbon distillate and a minor part corresponding to less than 20%, preferably
less than 10%, from 1% to 7% of a composition according to the invention.
Hydrocarbon distillates are distillates from direct or vacuum distillation, hydrotreated
distillates, distillates from catalytic cracking and/or hydrocracking of distillates under
vacuum, distillates resulting from conversion processes of the ARDS type and/or
viscoreduction, distillates from the upgrading of Fischer Tropsch cuts, and distillates
resulting from the conversion of plant and/or animal biomass, and plant and animal
oils, their hybrids, genetically modified species, hydrogenated or not, and the esters
of these oils, taken alone or in combination such as palm, rapeseed, sunflower, soya
and tallow oils, and their methyl and ethyl esters, taken alone or in a mixture.
The invention also relates to the composition of the invention as a substitute for
a hydrocarbon distillate as a fuel for diesel engines. In this case the composition is
used alone or in a mixture with distillates from the upgrading of Fischer Tropsch
cuts, and distillates resulting from the conversion of plant and/or animal biomass,
and plant and animal oils, their hybrids, genetically modified species, hydrogenated
or not, and the esters of these oils, taken alone or in combination such as palm,
rapeseed, sunflower, soya and tallow oils, and their methyl and ethyl esters, taken
alone or in a mixture.
The motor fuels or fuels according to the invention can also include any types
of additives such as detergents, dispersants, de-emulsifi'ers, biocides, anti-foaming
agents, reodorants, cetane improvers, anti-corrosion agents, friction, lubricity,
combustion, cloud point, flow point, anti-sedimentation and conductivity modifiers.
Preferably, the fuels for diesel engines will comprise from 1 to 2000 ppm,
preferably 1 to 1000 ppm and more preferably from 20 to 500 ppm of a lubricity
additive of the group constituted by at least one fatty acid with 5 to 24 carbon atoms
of plant or animal origin, optionally in a mixture with less than 10 % by weight of
resin acids of plant or animal origin and their esters obtained by reaction with mono-
and polyalcohols comprising from 1 to 5 OH. Preferred acids are fatty acids
containing from 8 to 24 carbon atoms.

Natural resin acids of plant origin are obtained from the distillation residues of
natural oils extracted from resinous trees, especially resinous conifers in particular
the pine.
Of the resin acids, abietic acid, dihydroabietic acid, tetrahydroabietic acid,
dehydroabietic acid, neoabietic acid, pimaric acid, levopimaric acid and parastrinic
and their derivatives are preferred.
Preferred esters are the esters obtained in the usual way from these fatty acids
or these resin acids as described above, with monoalcohols with 1 to 4 carbons or
polyols having 1 to 3 OH in particular glycol and glycerol.
The combustible fuel oils according to the invention can include all or some of
the above additives above as well as antioxidant additives.
Non-limitative examples are given in order to illustrate the advantages of the
present invention.
Example I: preparation of the POM compounds.
Sample 1: Preparation of the compound A3 % where n = 3 to 8 and X is the
methyl group: POM/MM 3 to 8.
100 g of methylal (1.32 mol) and 30 g of trioxane (1 mol) are loaded into a
double-jacketed 500 ml Schott reaction vessel fitted with a mechanical stirrer, a
coolant and a temperature probe. 5 g of Amberlyst A15 resin, washed beforehand
with methanol and dried under vacuum, is added. The mixture is heated to 50°C and
left to react for 1 hour. The reaction mixture is filtered, then washed with 10 g of a
15% aqueous soda solution. The methylal is eliminated by evaporation under
reduced pressure (90°C, 200 mbar) in the rotary evaporator, then the POM/MM is
eliminated by vacuum distillation (Oldershaw type column with 10 trays). 32 g of a
POM/MM-3.8 (CH3-(CH20)„-OCH3 cut where n is 3 to 8) or A3.8 is obtained.
The statistical distribution of the masses of the product obtained, determined by
GC analysis, is described in Table I.
Sample 2: Preparation of the POM/MM n = 3 to 4. or A3.4
The distillation cut between 60°C under 15 mbars and 86°C under 1 mbar is
recovered from sample 1 corresponding to the POM/MM where n is 3-4, or A3-4.
Sample 3: preparation of the compound A'3.8 where n' = 3-8 and X' is the
ethyl group: POM/EE 3 to 8.
The procedure is identical to Example 1 using 137 g of ethylal (1.32 mol), 30 g
of trioxane (1 mol) and 7 g of Amberlyst A15 resin. A mixture C2H 5-(CH20)n'-C2H 5
is obtained. The statistical distribution of the masses of the product obtained,
determined by GC analysis, is described in Table I.

Sample 4: Preparation of POM/EE n'= 3 to 4 or A'3-4.
The distillation cut between 79°C under 1 mbar and 58°C under 10"4 mbar is
recovered from Sample 3 corresponding to the POM/EE where n is 3-4.
Sample 5: preparation of the mixture of compounds An, AV and Bm where n,
n' and m = 2 to 8 and X is the methyl group and X' the ethyl group, starting from
75% methylal and 25% ethylal in moles: POM mixture A/B/A' 75/25 2 to 8 or
A/B/A'2.875M/25E.
271 g of methylal (3.57 mol), 122 g of ethylal (1.17 mol) and 107 g of trioxane
(3.57 mol) are loaded into a double-jacketed 1L Schott reaction vessel fitted with a
mechanical stirrer, a condenser and a temperature probe. 2 5 g of Amberlyst A15
resin, washed beforehand with methanol and dried under vacuum, is added. The
mixture is heated to 50°C and left to react for 1 hour. The reaction mixture is filtered,
then washed with 100 g of a 15% aqueous soda solution. The product is rectified by
evaporation under reduced pressure in the rotary evaporator (95°C, 100 mbar).
150 g of a mixture of compound A2-8 of formula CH3-(CH20)n-OCH3
(POM/MM), of compound A'2-8 of formula C2H5-(CH20)n-C 2H5 (POM/EE) and of
compound B2-g of formula CH3-(CH20)m-OC2H5 (POM/ME) where n, n' and m are
comprised between 2 and 8 is obtained. The statistical distribution of the masses of
the mixture obtained, determined by GC analysis, is described in Table I.
Sample 6: Preparation of the ternary mixture of POM An/Bm/A'n' (75/25)
where n, n', m = 2 to 4 or A/B/A'2.4 75M/25E.
The distillation cut between 60°C under 15 mbars and 58°C under 10"4 mbar is
recovered from Sample 5 corresponding to the ternary mixture of POM An/Bm/AV
75/25 where n, n', m range from 2 to 4 or A/B/A'2.4 75M/25E.
Sample 7: Preparation of the mixture of compounds A„, AV and Bm where n,
n' and m = 2 to 8 and X is the methyl group and X' the ethyl group, starting from
50% methylal and 50% ethylal in moles: POM mixture called A/B/A' 2-g 50M/50E.
The procedure is identical to that of Sample 3 using 180 g of methylal (2.37
mol), 246 g of ethylal (2.37 mol), 107 g of trioxane (3.57 mol) and 25 g of Amberlyst
A15 resin. A mixture is obtained, the statistical distribution of the masses of which,
determined by GC analysis, is described in Table I.
Sample 8: Preparation of the ternary mixture of POM An/Bm/A'n- (50/50)
where n, n', m = 2 to 4 or A/B/A'24 50M/50E.
The distillation cut between 60°C under 15 mbars and 58°C under 10"4 mbar is
recovered from Sample 4 corresponding to the ternary mixture of POM A/B/A 50/50
where n, n', m range from 2 to 4.
Sample 9: Preparation of the mixture of compounds An, AV and Bm where n,
n' and m = 2 to 8 and X is the methyl group and X' the ethyl group, starting from

25% methylal and 75% ethylal in moles: POM mixture An/Bm/An-' (25/75) n, n' and
m varying from 2 to 8 or A/B/A2.8 25M/75E.
The procedure is identical to that of Sample 3 using 90 g of methylal (1.18
mol), 370 g of ethylal (3.56 mol), 107 g of trioxane (3.57 mol) and 25 g of Amberlyst
A15 resin. A mixture is obtained, the statistical distribution of the masses of which,
determined by GC analysis, is described in Table I.
Sample 10: Preparation of the ternary mixture of POM An/Bm/AV (25/75)
where n, n', m = 2 to 4 or A/B/A'2-4 25M/75E.
The distillation cut between 60°C under 15 mbars and 58°C under 10"4 mbar is
recovered from Sample 5 corresponding to the ternary POM mixture An/Bm/AV
(25/75) where n, n', m range from 2 to 4.
Sample 11: Preparation of the binary mixture AaVAV^ with 25% POM/MM
and 75% POM/EE or 25A3V75A'3-4
This preparation is carried out by simple mixing at ambient temperature of
approximately 25°C of 25% by mass of Sample 2 and 75% of Sample 4.


Example II: Preparation of different compositions of diesel fuel according to the
invention.
This mixing is carried out under stirring at the ambient temperature of 25°C
between a diesel fuel constituted by a gas oil of EN 590 type containing less than 500
ppm of sulphur, here less than 50 ppm of sulphur with different % by volume of the
different compositions of POM obtained in Example I.
In Table II the results show
-by way of comparison, columns CI, C2, C3, the effect on the properties of the
gas oils of the addition of 3.5% or 7% by volume of the compounds of the prior art of
formula A 3-8 POM/MM (Sam 1) or of formula A'3-8 POM/EE (Sam 2) in which n=3-
8andX=MeandX'=Et;

- column Yl, the effect on the properties of the gas oils of the addition of 3.5%
by volume of Sample 6 constituted by a binary mixture A/A' comprising 25%
POM/MM and 75% POM/EE.
- column Y2, the effect on the properties of the gas oils of the addition of 3.5%)
by volume of Samples 6, 8, 10; these mixtures correspond to distillation cuts where
n, n' and m range independently from 2 to 4 and are obtained with different % in
moles of ethylal and methylal according to the process described above:
Y2a corresponds to a methylal/ethylal or M/E ratio of 75/25;
Y2b corresponds to a methylal/ethylal or M/E ratio of 50/50;
Y2c corresponds to a methylal/ethylal or M/E ratio of 25/75.
The results of Table II show that the incorporation of the POM compositions
according to the invention delivers the best results in terms of improvement of the
visual aspect of the distillate composition, preservation of the CFPP and the blocking
tendency.
The CFPP is measured according to the standard NF EN116 and the blocking
tendency is measured according to the standard IP 387.

Example III: Synergistic effect on the lubricity of the motor fuel of the combination
of the compositions according to the invention and a lubricity additive
A standard EN590 desulphurized gas oil containing 8 ppm of sulphur is used
for this example. Several samples were prepared by mixing this gas oil with two
types of compounds according to the invention referred to above and into which were
introduced three types of compounds giving the desulphurized gas oils additional
lubricity properties. The first compound called Li is a lubricity additive of fatty acid
type in a mixture with resin acids. It is more specifically constituted by a mixture of a
combination of fatty acids comprising, by weight, 50 to 55% oleic acid, 30 to 40%
linoleic acid, 3 to 5% palmitic acid with approximately 2% resin acid derived from
pine oil (tall oil). This type of additive is already described in the examples of the
Application EP 1340801 as producing synergistic effects in the compositions of
motor fuel for diesel engines. The second, called L2, is also a lubricity additive of
ester type. It is more specifically constituted by a glycerol ester, principally an ester
based on glycerol oleate and/or linoleate. The third is a plant oil ester, rapeseed
methyl ester called RME.
A first table lists the lubricity performance values of each of these compounds
taken alone or in a mixture with at least one of the compounds of the invention, the
lubricity performance values being measured using the HFRR test according to the
standard ENISO 12156.

The compounds according to the invention display a virtually non-existent, if
anything even negative, lubricity, the results in the HFRR tests showing higher wear
figures. When they are used in combination with a lubricity additive (Li or L2) an
improvement is noted. On the other hand, the rapeseed methyl ester (RME) has only
a small effect on the lubricity of the compounds according to the invention. Tests
were carried out on gas oils to verify whether this beneficial effect of the
combination of lubricity additives with these products was also visible: this is the
subject of Table IV below.


It is established that the beneficial effects of the lubricity additives on the
mixtures of gas oil/compounds according to the invention are even more pronounced:
they are actually close to simple mixtures of gas oils and lubricity additives.
In conclusion, the addition of a lubricity additive (in acid form or in ester form)
to the gas oil containing 3.5% of POMM allows the lubricity of the mixture to be
greatly improved.
"None of the biological materials used in the instant invention has been obtained from India."

WE CLAIMS
1. Composition comprising
a) a mixture of at least one compound An of formula X-(O-CH2)n-O-X in
which n represents an integer from 1 to 5 where X is represented by the formula
CzH2z+1 in which z is an integer from 1 to 10, with at least one compound A'o of
formula X'-(O-CH2)n-O-X' in which n' represents an integer from 1 to 5, where X'
is represented by the formula CzH2z+1 in which z is an integer from 1 to 10, a mixture
in which An and A'n' are different from each other and X and X' are different from
each other, said mixture comprising from 25 to 75% by mass of A„ and from 75 to
25% by mass of A'n', relative to the total composition;
or
b) a mixture comprising the compounds An and A9n described above
with at least one compound Bm of formula X-(O-CH2)m-O-X' in which m represents
an integer from 1 to 5, X and X' are different from each other and X and X' are
represented by the formula CzH2z+1 in which z is an integer from 1 to 4, a mixture in
which An, A'n- and Bm are independently present in ranges by weight ranging from
1% to 90% for each of them, the total of the % of each compound making 100 %..
2. Composition as claimed in claim 1 in which z is 1 or 2.
3. Composition as claimed in one of claims 1 to 2, comprising a mixture
of the compounds An and A'n-, a mixture in which, relative to the total composition,
An is present at from 45% to 55% by mass and AV is present at from 55% to 45% by
mass.
4. Composition as claimed in one of claims 1 to 3 comprising a mixture
of the compounds A„ and A'n-, a mixture comprising, relative to the total
composition, 50 % to 75 % by mass of compounds An-' where X' represents the C2H5
group and 25 % to 50 % by mass of compounds An or X represents the CH3 group.
5. Composition as claimed in claim 4 comprising a mixture of
compounds of formula An, A'n- and Bm with 1% to 40% by mass for An, 20% to 50%
by mass for Bra and 10% to 90% by mass for AV the total of the % of each
compound making 100% and in which X represents the CH3 group and X' represents
the C2H 5 group.

6. Composition as claimed in one of claims 1 to 5 in which n, n' and m
represent independently an integer from 2 to 5 and comprising more than 60% by
mass of compounds where n, n' and m range from 3 to 4.
7. Composition as claimed in one of claims 1 to 6 in which n, n' and m
represent independently an integer from 2 to 4 and comprising 60% to 95 % by mass
of compounds where n, n' and m range from 3 to 4.
8. Hydrocarbon distillate comprising a composition as claimed in one of
claims 1 to 7 in a proportion by mass that does not worsen the CFPP (measured
according to the standard NF EST 116) by more than 5°C and producing a
deterioration of the blocking tendency (measured according to the standard IP 387)
of from 0 to less than 20%.
9. Hydrocarbon distillate as claimed in claim 8 comprising a proportion
from 1% to less than or equal to 20% by volume, preferably from 1% to less than or
equal to 10%, preferably from 1% to 10% by volume of a composition as claimed in
one of claims 1 to 7.
10. Distillate as claimed in one of the claims 8 or 9 comprising at least
one hydrocarbon cut originating from the group constituted by distillates with a
boiling point comprised between 150°C and 450°C comprising the direct distillation
distillates, vacuum distillates, hydrotreated distillates, distillates originating from the
catalytic cracking and/or hydrocracking of distillates under vacuum, distillates
resulting from conversion processes of the Atmospheric Residue Desulphurization
type and/or viscoreduction, distillates originating from the upgrading of Fischer
Tropsch cuts, distillates resulting from the conversion of plant and/or animal
biomass, taken alone or in combination, and plant and animal oils, their hybrids,
hydrogenated or not, and the esters of these oils, taken alone or in combination.
11. Hydrocarbon distillate as claimed in one of claims 8 to 10, comprising
as additives: detergents, dispersants, de-emulsifiers, anti-foaming agents, biocides,
reodorants, cetane improvers, anti-corrosion agents, antioxidants, friction modifiers,
lubricity, combustion, cloud point, flow point, anti-sedimentation and conductivity
improvers.
12. Fuel comprising 1 to 100% of the composition as claimed in one of
the claims 1 to 7 and 1 to 2000 ppm, preferably 1 to 1000 ppm and more preferably
20 to 500ppm of a lubricity additive of the group constituted by at least one fatty acid

with 5 to 24 carbon atoms of plant or animal origin, and their esters obtained by
reaction with mono- and polyalcohols comprising 1 to 5 OH.
13. Fuel as claimed in claim 12 for which the lubricity additive is chosen
from fatty acids containing from 8 to 24 carbon atoms, and the esters of these fatty
acids with monoalcohols having 1 to 4 carbon atoms or polyols with 1 to 3 OH
preferably polyols such as glycol and glycerol.
14. Fuel as claimed in one of claims 12 or 13 comprising the said
composition alone or in a mixture with distillates originating from the upgrading of
Fischer Tropsch cuts, and/or distillates resulting from the conversion of plant or
animal biomass, and/or plant and/or animal oils, their hybrids, genetically modified
species, hydrogenated or not, and the esters of these oils, taken alone or in
combination.
15. Fuel as claimed in one of claims 12 to 14 comprising from 1% to less
than 20% preferably from 1% to less than 10% or 1% to 7% of a composition as
claimed in one of claims 1 to 10 and more than 80% of a hydrocarbon distillate
chosen from distillates originating from direct or vacuum distillation, hydrotreated
distillates, distillates originating from the catalytic cracking and/or hydrocracking of
vacuum distillates, distillates resulting from conversion processes of Atmospheric
Residue Desulphurization type and/or viscoreduction, distillates originating from the
upgrading of Fischer Tropsch cuts, distillates resulting from the conversion of plant
or animal biomass, and plant and/or animal oils, their hybrids, hydrogenated or not,
and the esters of these oils, taken alone or in combination.
16. Diesel fuel comprising 1 to 100% of the composition as claimed in
one of claims 1 to 7 and 1 to 2000 ppm, preferably 1 to 1000 ppm and more
preferably 20 to 500 ppm of a lubricity additive.
17. Diesel fuel as claimed in claim 16 comprising in a mixture the
composition with distillates originating from the upgrading of Fischer Tropsch cuts,
and/or distillates resulting from the conversion of the plant or animal biomass, and/or
plant and/or animal oils, their hybrids, genetically modified species, hydrogenated or
not, and the esters of these oils, taken alone or in combination.
18. Diesel fuel as claimed in one of the previous claims 16 or 17
comprising more than 80% of a hydrocarbon distillate and from 1% to less than 20%,
preferably from 1% to less than 10%, in particular 1% to 7% of the composition

according to one of claims 1 to 10, and at least one additive, preferably a lubricity
additive.
19. Diesel fuel as claimed in one of claims 16 to 18 comprising from 0 to
less than 1000 ppm of sulphur, preferably from 0 to less than 500 ppm, from 0 to less
than 50 ppm, and preferably from 0 to 20 ppm of sulphur.

ABSTRACT

MIXTURE OF SYMMETRICAL AND ASYMMETRICAL POLYOXYMETHYLENE
DIALKYLETHERS AND THEIR USE IN HYDROCARBON DISTILLATES
The invention relates to the use of organic compounds of the
polyoxymethylene dialkylethers type as a component in hydrocarbon distillates in
particular gas oils of compositions comprising
a) a mixture of at least one compound An of formula X-(O-CH2)n-O-X in
which n represents an integer from 1 to 5 where X is represented by the formula
CZH2Z +1 in which z is an integer from 1 to 10, with at least one compound A'n' of
formula X'-(O-CH2)n'-O-X' in which n' represents an integer from 1 to 5, where X'
is represented by the formula CzH2Z+1 in which z is an integer from 1 to 10, a mixture
in which An and A'n' are different from each other and X and X' are different from
each other;
or
b) a mixture comprising the compounds An and A'n- described above
with at least one compound Bm of formula X-(O-CH2)m-O-X' in which m represents
an integer from 1 to 5, X and X' are different from each other and X and X' are
represented by the formula CzH2Z+1 in which z is an integer from 1 to 10.