[0001] The present invention relates to improvements in fuels derived wholly or in part
from animal or vegetable oil sources. Such fuels are called herein Bx fuels. Bx fuels
may be derived entirely from animal or vegetable oil sources (B100 fuels) or they
may comprise a proportion of fuels derived from animal or vegetable oil sources, admixed
with fuels from other sources (for example mineral sources, or synthetic sources,
e.g. Fischer-Tropsch sources). For example B20 herein is a fuel in which 20 wt% of
the fuel is from animal or vegetable oil sources and 80 wt% of the fuel is from other
sources. The proportion may be lower still, as in the case of, for example, a B5 fuel.
[0002] A problem has become apparent in Bx fuels,: blocking of filters in distribution systems
and vehicles by precipitates in such fuels, typically at temperatures above the cloud
point (CP) of the fuels, The problems have been seen in a wide range of Bx fuels,
from B100 down to B5.
[0003] WO 2007/076163 describes such problems, and suggests that the problem of filter blocking arises
as a result of the precipitation of crystals of steryl glycosides in fuels derived
from biological sources. Steryl glycosides are found in plants and it is suggested
that they are carried over into Bx fuels.
[0004] WO 2007/076163 proposed a solution to the filter blocking problem; namely the removal of the steryl
glycosides, for example using an adsorbent as an additive in conjunction with a process
of filtration or centrifugation, or both. In one example soy biodiesel was filtered
through a bed of diatomaceous earth.
[0005] The proposals of
WO 2007/076163 have the disadvantage that a separation step is needed, in addition to the treatment
of the Bx fuel with the additive.
[0006] We are not bound by the explanation for the problem given in
WO 2007/076163. We believe it might be more complex, for example also relating to the total glycerides
content, including monoglycerides, diglycerides and triglycerides, saturated or unsaturated.
We are certainly of the view that such problems now seen in Bx fuels are connected
with the Bx fuel component which is derived from vegetable or animal sources, and
are quite different from precipitation problems which have arisen in the past predominantly
in mineral fuels. The present invention seeks to solve this new problem notwithstanding
that an agreed scientific explanation of its nature or cause may follow.
[0007] By mineral fuels herein we mean fuels derived wholly from mineral (i.e. petroleum)
sources. By mineral fuel component herein we mean the mineral-derived component in
a Bx fuel.
[0008] Filter blocking problems can occur at temperatures below the cloud point in mineral
and other fuels. Such problems have been closely analysed over many years. Additives
have been developed that allow fuels to be used at lower temperatures than would otherwise
be possible.
[0009] The source of the problem of precipitation below the cloud point is the presence
of components such as so-called "waxes" (for example n-alkanes and methyl n-alkanoates
that crystallise at low temperatures). This may cause the fuels to block filters and
to become non-pourable.
[0010] Standardised tests have been devised to measure the temperature at which the fuel
hazes (the cloud point - CP), the lowest temperature at which a fuel can flow (the
pour point - PP) and the cold filter plugging point - CFPP); and the changes thereto
caused by additives (ΔCP, ΔPP, ΔCFPP). The standardised tests for measuring PP and,
especially, CP and CFPP are among the common working tools for persons skilled in
the art. CP and CFPP may be further described as follows:
Cloud Point (CP)
[0011] The cloud point of a fuel is the temperature at which a cloud of wax crystals first
appears in a liquid when it is cooled under conditions prescribed in the test method
as defined in ASTM D 2500.
[0012] Until recently, it was considered that problems arising from the formation of precipitates
would not occur at temperatures above the cloud point.
Cold Filter Plugging Point (CFPP)
[0013] At temperatures below the cloud point but above the pour point, the wax crystals
can reach a size and shape capable of plugging fuel lines, screens, and filters even
though the fuel will physically flow. These problems are well recognized in the art
and have a number of recognised test methods such as the CFPP value (cold filter plugging
point, determined in accordance with DIN EN 116).
[0014] Tests such as these were introduced to give an indication of low temperature operability
as the cloud point test was considered to be too pessimistic.
[0015] US 5743923 describes the improvement of the low temperature properties of a blend of biofuel
and petroleum based fuel oil by addition of an ethylene-unsaturated ester copolymer,
a comb polymer, a polar N compound or a a compound having at least one linear alkyl
group connected to a non-polymeric organic residue.
[0016] WO2007/147753 describes a paraffin dispersant for fuels, especially having a biodiesel content
comprising polar oil-soluble nitrogen compounds and acid amides.
[0017] WO96/22344 describes chemical markers as additives in fuel oil compositions to improve filterability
at temperatures above its cloud point.
[0018] US2008/0016754 describes additive mixtures as cold flow additives for middle distillate fuels comprising
a terpolymer of ethylene, propene and at least one ethylenically unsaturated ester
and a further additive selected from copolymers of ethylene and ethylenically unsaturated
compounds, comb polymers and mixtures thereof.
[0019] The cold flow improvers (CFIs) and wax anti-settling additives (WASAs) which have
been devised considerably ameliorate the problems of precipitation below the cloud
point in fuels, and their effect can studied by the test methods described above,
comparing the results between unadditised fuels and additised fuels.
[0020] Some such additives may assist in keeping the so-called "waxes" in solution in the
mineral fuel; others may alter their crystal morphology or size, so that filterability
and pourability are maintained in spite of precipitation.
[0021] The additives devised to deal with the problems arising from precipitation below
the cloud point have been very successful, to the extent that such fuels, suitably
additised with, for example, CFIs (with or without WASAs), can be used even in severe
low temperature conditions. In many fuels the CFPP value may be lowered by 10-20°C,
compared with corresponding fuels without additives.
[0022] Additives are also known which improve the CFPP of Bx grades, including B100 grade,
and thus it would be expected that fuels treated in this way should have no operating
problems even at temperatures significantly below the CP of the fuels.
[0023] However, as noted above, the problems which have emerged in Bx fuels are very different
from those which can arise in mineral fuels. In particular the precipitates cause
filter blocking with Bx fuels at temperatures above the cloud point, whereas precipitation
problems in mineral fuels occur below the cloud point, and generally at much lower
temperatures; and the chemical nature of the precipitates is believed to be entirely
different. As noted above the origin of the precipitation, though not fully understood,
is believed to be entirely different - specific compounds found in animal or vegetable
sources, and not found in mineral sources. The testing regimes described above are
inappropriate for testing these precipitation issues in Bx fuels because they fail
to predict adequately the temperature at which filters are likely to block in real
life situations such as in storage, distribution and use in vehicles and heating systems.
[0024] One of the reasons for this failure is believed to be that the precipitation occurs
during a period of "cold soaking" over several hours or longer and therefore is not
detected by tests such as Cloud Point or CFPP.
[0025] Critically, the precipitate does not redissolve when the temperature is raised again.
This is very different to conventional wax precipitation where at temperatures above
the cloud point, wax can readily redissolve, particularly if kept dispersed in the
fuel through use of WASAs.
[0026] Without Wishing to be bound by theory, we believe that the precipitates causing the
problem of filter blocking at temperatures above the cloud point are present 5 as
minor constituents within the B100 and are more soluble in the B100 than in mineral
fuels and hence in Bx blends. Furthermore, it is thought that as the polarity of the
mineral fuel is decreased for example removal of sulphur, the solubility of these
constituents will be even less and the problem will be exacerbated.
[0027] In the light of differences, in the nature of these precipitation phenomena below
and above the cloud point, additives developed to solve a problem arising from precipitation
below the cloud point, predominantly in mineral fuels, are not promising starting
points to solve a problem arising from precipitation in a Bx fuel, arising from the
fuel component derived from an animal or vegetable oil. Indeed, it must be borne in
mind that Bx fuels have already contained additives of the type used to improve flow
properties below the cloud point; and yet the new problems of higher temperature filter
blocking have still arisen.
[0028] However, we have now found that, unexpectedly, there is one class of additive which
is particularly effective at improving the flow properties, and hence the filterability,
of Bx fuels above the cloud point. This class was already known to improve the flow
properties of fuels below the cloud point. The finding of one class of additive which:
- (a) improves the flow properties of fuels having an animal or vegetable origin above
the cloud point, and
- (b) improves the flow properties of fuels, including mineral fuels, below the cloud
point;
notwithstanding the different nature of the fuels and, in particular, the different
nature of the respective problems and precipitates, is serendipitous.
[0029] In accordance with a first aspect of the present invention there is provided the
use of a reaction product of (i) a compound containing the segment -NR
1R
2 where R
1 represents a group containing from 4 to 44 carbon atoms and R
2 represents a hydrogen atom or a group R
1, and (ii) carboxylic acid having from 1 to 4 carboxylic acid groups or an acid anhydride
or acid halide thereof, in order to improve the filterability of a Bx fuel above the
cloud point of the Bx fuel;
wherein the Bx fuel comprises fuel derived from animal or vegetable oil sources admixed
with fuel derived from mineral or synthetic sources;
wherein the Bx fuel has a sulphur content less than 200ppm;
wherein the Bx fuel contains at least 4 wt% of fuel derived from animal or vegetable
sources;
and wherein the additive is present in the Bx fuel in an amount (as active material)
of from 10 mg/kg up to 200 mg/kg.
[0030] Preferably R
1 is a hydrocarbyl group or a polyethoxylate or polypropoxylate group.
[0031] Preferably the group R
1 is a hydrocarbyl group. Preferably the group R
1 is predominantly a straight chain group.
[0032] The term "hydrocarbyl" as used herein denotes a group having a carbon atom directly
attached to the remainder of the molecule and having a predominantly aliphatic hydrocarbon
character. Suitable hydrocarbyl based groups may contain non-hydrocarbon moieties.
For example they may contain up to one non-hydrocarbyl group for every ten carbon
atoms provided this non-hydrocarbyl group does not significantly alter the predominantly
hydrocarbon character of the group. Those skilled in the art will be aware of such
groups, which include for example hydroxyl, halo (especially chloro and fluoro), alkoxyl,
alkyl mercapto, alkyl sulfoxy, etc. Preferably the group R
1 is an-organic group entirely predominantly containing carbon and hydrogen atoms.
[0033] A hydrocarbyl group R
1 is preferably predominantly saturated, that is, it contain no more than one carbon-to-carbon
unsaturated bond for every few (for example six to ten) carbon-to-carbon single bonds
present. In the case of a hydrocarbyl group R
1 having from 4 to 10 carbon atom it may contain one unsaturated bond. In the case
of a hydrocarbyl group R
1 having from 11 up to 20 carbon atom it may contain up to two unsaturated bonds. In
the case of a hydrocarbyl group R
1 having from 21 up to 30 carbon atom it may contain up to three unsaturated bonds.
In the case of a hydrocarbyl group R
1 having from 31 up to 40 carbon atom it may contain up to four unsaturated bonds.
In the case of a hydrocarbyl group R
1 having from 41 up to 44 carbon atom it may contain up to five unsaturated bonds.
Preferably, however, a hydrocarbyl group R
1 is preferably a fully saturated alkyl group, preferably a fully saturated n-alkyl
group.
[0034] Preferably a group R
1 comprises from 6 to 36 carbon atoms, prelerably 8 to 32, preferably 10 to 24, preferably
12 to 22, most preferably 14 to 20.
[0035] It will be appreciated that the group R
1 will typically include moieties with a range of carbon atoms. The definitions C
4-44..... C
14-22 are not intended to denote that all R
1 groups must fall within the stated range.
[0036] The group R
2, when present, preferably conforms to the same definitions as are given for R
1. R
1 and R
2 need not be the same. Preferably, however, R
1 and R
2 are the same.
[0037] Preferably the species (ii) is a carboxylic acid or an acid anhydride thereof.
[0038] However if an acid halide is used it is preferably an acid chloride.
[0039] Suitable compounds (i) include primary, secondary, tertiary and quaternary amines.
Tertiary and quaternary amines only form amine salts.
[0040] Secondary amines, of formula HNR
1R
2, are an especially preferred class of compounds (i). Examples of especially preferred
secondary amines include di-octadecylamine, di-cocoamine, di-hydrogenated tallow amine
and methylbehenyl amine. Amine mixtures are also suitable such as those derived from
natural materials. A preferred amine is a secondary hydrogenated tallow amine, the
alkyl groups of which are derived from hydrogenated tallow fat composed of approximately
3-5%wt C
14, 30-32%wt C
16, and 58-60%wt C
18.
[0041] Quaternary amines, of formula [+NR
1-R
2R
3R
4 -An], are an especially preferred class of compounds (i). R
1 and R
2 are as defined above (but R
2 is not hydrogen). R
3 and R
4 independently represent a C(1-4) alkyl group, preferably propyl, ethyl or, most preferably,
methyl. +NR
1R
2(CH
3)
2 represents a preferred cation. -An represents the anion. The anion may be any suitable
species but is preferably a halide, especially a chloride. Where (i) comprises a quaternary
amine, the reaction conditions maybe adjusted to assist the reaction between (i) and
(ii). Preferably the reaction conditions are adjusted by the introduction of an auxiliary
base. The auxiliary base is preferably an inorganic base, such as sodium methoxide,
sodium ethoxide, or sodium hydroxide. Preferably the inorganic base is a metal alkoxide
or metal hydroxide. Alternatively, the quaternary amine salt may be preformed as the
corresponding basic salt, for example, a quaternary ammonium hydroxide or alkoxide.
[0042] Also preferred are mixtures of primary and secondary amines, as species (i).
[0043] Also preferred are mixtures of secondary and quaternary amines, as species (ii).
[0044] Preferred carboxylic acids include carboxylic acids containing two, three or four
carboxylic acid groups, and acid anhydrides and acid halides thereof.
[0045] Examples of suitable carboxylic acids and their anhydrides induce aminoalkylenepolycarboxylic
acids, for example nitrilotriacetic acid, propylene diamine tetraacetic acid, ethylenediamine
tetraacetic acid, and carboxylic acids based on cyclic skeletons, e.g., pyromellitic
acid, cyclohexahe-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic
acid and naphthalene dicarboxylic acid, 1,4-dicarboxylic acids, and dialkyl spirobislactones.
Generally, these acids have about 5 to 13 carbon atoms in the cyclic moiety. Preferred
acids useful in the present invention are optionally substituted benzene dicarboxylic
acids, e.g. phthalic acid, isophthalic acid, and terephthalic acid, and their acid
anhydrides or acid chlorides. Optional substituents include 1-5 substituents, preferably
1-3 substituents, independently selected from C(1-4)alkyl, C(1-4)alkoxy, halogen,
C(1-4)haloalkyl, C(1-4)haloalkoxy, nitrile, -COOH, -CO-OC(1-4)alkyl, and-CONR
3R
4 where R
3 and R
4 are independently selected from hydrogen and C(1-4)alkyl. Preferred halogen atoms
are fluorine, chlorine and bromine However unsubstituted benzene carboxylic acids
are preferred. Phthalic acid and its acid anhydride are particularly preferred.
[0046] Preferably the molar ratio of compound (i) to acid, acid anhydride or acid halide
(ii) is such that at least 50% of the acid groups (preferably at least 75%, preferably
at least 90%, and most preferably 100%) are reacted in the reaction between the compounds
(i) and (ii), for example to form the amide and/or the amine salt.
[0047] Where compound (ii) comprises one or more free carboxylic acid groups, reaction conditions
may be adjusted to allow reaction between compounds (i) and (ii), for example to form
the respective amide or amine salt. The reaction conditions may be adjusted by raising
reaction temperatures. The reaction conditions may be adjusted by including a dehydrating
agent within the reaction mixture. The one or more carboxylic acid groups may be activated
in
situ ready for coupling (i) and (ii), for example, by the use of such as carbodiimides
(eg. EDCl). However, where activated forms of (ii) are employed, the activated forms
of (ii) are preferably preformed, for example, as acid halides or acid anhydrides.
Acid anhydrides are most preferred.
[0048] In the case of a preferred reaction, between a compound (i) and a dicarboxylic acid,
or acid anhydride or acid halide thereof, preferably the molar ratio of compound (i)
(or mixtures of compounds (i), in that situation) to acid, acid anhydride or acid
halide (ii) (or mixed compounds (ii), in that situation) is at least 0.7:1, preferably
1:1, preferably at least 1.5:1. Preferably it is up to 3:1, preferably up to 2.5:1.
Most preferably it is in the range 1.8:1 to 2.2:1. A molar ratio of 2:1, (i) to (ii)
is especially preferred. Also preferred is a molar ratio of 1:1.
[0049] It will be understood by those skilled in the art that compound (ii) is defined as
the original starting material. However, preferred products may be obtained by step-wise
reactions involving reacting compound (i) with an adduct of compound (ii), particularly
where (ii) has already reacted in with a compound (i) to form an intermediate. Such
an intermediate may be fully isolated or partially isolated so as to allow step-wise
reactions. Such an intermediate may comprise a mono-amide/mono-carboxylic acid adduct,
for instance, where in a first step a first equivalent of (i) is reacted with a dicarboxylic
acid, acid anhydride, or acid halide. Partial isolation may therefore be mere isolation
of the reaction mixture resulting from the first step of a reaction to form the mono-amide/mono-carboxylic
acid. In such circumstances, a subsequent reaction of compound (i) (optionally a different
compound (i) than that used in the first step) with the mono-amide/mono-carboxylic
acid adduct may yield further derivatives, for instance, a diamide or a mono-amide/ammonium
carboxylate salt. Such a step-wise process provides for greater selectivity of either
or both of an amide group and/or an ammonium salt, especially where the amines of
said amide group and said ammonium group are different, such as when (i) essentially
comprises more than one amine.
[0050] In the case of a preferred reaction, between a secondary amine as the only compound
(i) and a dicarboxylic acid, or acid anhydride or acid halide thereof, preferably
the molar ratio of-amine (i) to acid, acid anhydride or acid halide (ii) is at least
1:1, preferably at least 1.5:1. Most preferably it is in the range 1.8:1, to 2.2:1.
A molar ratio of 2:1, (i) to (ii) is especially preferred.
[0051] In the case of another preferred reaction, between a quaternary ammonium salt as
the only compound (i) and a dicarboxylic acid, or acid anhydride or acid halide thereof,
preferably the molar ratio of quaternary ammonium salt (i) to acid, acid anhydride
or acid halide (ii) is at least 1:1, preferably at least 1.5:1. Most preferably it
is in the range 1.8:1 to 2.2:1. A molar ratio of 2:1, (i) to (ii) is especially preferred.
[0052] Preferred reaction products for use in this invention contain at least the mono-amide
adduct and quaternary ammonium salt and this may be achieved by using a mixture of
compounds as compound (i), preferably both a secondary amine and a quaternary ammonium-compound.
[0053] Another preferred reaction employs both a secondary amine and a quaternary ammonium
salt as compounds (i). Preferably the ratio of the secondary amine to the quaternary
ammonium salt in the reaction mixture is 30-70% to 70-30% molar/molar, preferably
40-60% to 60-40%, and most preferably they are present in equimolar amounts. Consistent
with what is stated above, 11 therefore, this reaction employs in its most preferred
embodiment equimolar amounts of the secondary amine, the quaternary ammonium salt
and the acid, acid anhydride or acid halide (ii).
[0054] Preferably the reaction between the compound (i) and the carboxylic acid, acid anhydride
or acid halide forms one or more amide, imide or ammonium salts, combinations of these
within the same compound, and mixtures of these compounds.
[0055] Thus, in one preferred embodiment a dicarboxylic acid, acid anhydride or acid halide
is reacted with a secondary amine in a mole ratio of 1:2 such that one mole of the
amines form an amide and one mole forms an ammonium salt.
[0056] An especially preferred additive is a N,N-dialkylammonium salt of 2-N',N'-dialkylamide
benzoic acid, which suitably is the reaction product of di(hydrogenated) tallow amine
(i) and phthalic acid or its acid anhydride (ii); preferably at a molar ratio of 2:1.
[0057] An especially preferred additive is the reaction product of di(hydrogenated) tallow
amine (i) and phthalic acid or its acid anhydride (ii); preferably at a molar ratio
of 1:1.
[0058] Other preferred additives are the reaction products (hydrogenated) tallow amine with
EDTA reaction in a molar ratio of 4:1 with removal of four moles of water or two moles
of water to form respectively the tetraamide derivative or the diamide diammonium
salt derivative.
[0059] Another preferred additive is the reaction product of one mole of alkylspirobislactone,
for example dodecenyl-spirobislactone with one mole of mono-tallow amine and one mole
of di-tallow amine.
[0060] The fuel composition of the present invention contains at least 4 wt% of fuel derived
from animal or vegetable sources, 12
preferably at least 5 wt%, at least 6 wt%, at least 8 wt%, or at least 10 wt%, of
fuel derived from animal or vegetable sources. Some embodiments may contain at least
15 wt%, or at least 20 wt%, of fuel derived from animal or vegetable sources. The
fuel composition may contain up to 99 wt% of fuel derived from animal or vegetable
sources, for example up to 95 wt%, up to 90 wt%, up to 85 wt%, up to 80 wt%, up to
75 wt%, up to 70 wt%, up to 60 wt%, up to 50 wt%, up to 40 wt%, up to 30 wt%, up to
25 wt%, up to 20 wt%, up to 15 wt%, or up to 12 wt%, of fuel derived from animal or
vegetable sources.
[0061] A fuel which comprises 100% fuel produced from an animal or vegetable source is denoted
as B100, a fuel which comprises 90% mineral diesel and 10% biodiesel is known as B10;
fuel comprising 50% mineral diesel and 50% biodiesel is known as B50; and so on.
[0062] Fuel of animal or vegetable origin may include ethyl or methyl esters of fatty acids
of biological origin. Starting materials for the production of such fuel include,
but are not limited to, materials containing fatty acids. These materials include,
without limitation, triacylglycerols, diacylglycerols, monoacylglycerols, phospholipids,
esters, free fatty acids, or any combinations thereof. The diesel is produced by incubating
the material including the fatty acids with a short chain alcohol in the presence
of heat, pressure, a catalyst, or combinations of any thereof to produce fatty acid
esters of the short chain alcohols.
[0063] The fatty acids used to produce the fuel may originate from a wide variety of natural
sources including, but not limited to, vegetable oil, canola oil, safflower oil, sunflower
oil, nasturtium seed oil, mustard seed oil, olive oil, sesame oil, soybean oil, com
oil, peanut oil, cottonseed oil, rice bran oil, babassu nut oil, castor oil, palm
oil, palm oil, rapeseed oil, low erucic acid rapeseed oil, palm kernel oil, lupin
oil, jatropha oil, coconut oil, flaxseed oil, evening primrose oil, jojoba oil, camelina
oil, tallow, beef tallow, butter, chicken fat, lard, dairy butterfat, shea butter,
used frying oil, oil miscella, used cooking oil, yellow trap grease, hydrogenated
oils, derivatives of the oils, fractions of the oils, conjugated derivatives of the
oils, and mixtures of any thereof. grease, hydrogenated oils, derivatives of the oils,
fractions of the oils, conjugated derivatives of the oils, and mixtures of any thereof.
[0064] Preferably the precipitates which form above the cloud point and which the present
invention seeks to combat are not revealed by cloud point test ASTM D 2500.
[0065] Preferably the precipitates which form above the cloud point and which the present
invention seeks to combat are not revealed immediately merely by cooling the fuel
to a given temperature. Preferably they form following an incubation period, by holding
the fuel at a temperature above the cloud point for a incubation period. Preferably
the incubation period is at least 4 hours, preferably at least 12 hours, preferably
at least 16 hours, preferably at least 48 hours, preferably at least 96 hours.
[0066] Preferably the precipitates which form above the cloud point and which the present
invention seeks to combat are not removed merely by raising the temperature of the
fuel above the temperature at which they formed.
[0067] Preferably the Bx fuel is a middle distillate fuel, generally boiling within the
range of from 110 to 500, e.g. 150 to 400° C. Preferably it is a Bx fuel for use in
diesel engines or heating fuel oil.
[0068] In one embodiment the fuel is B100. Preferably however the fuel is a blend of fuel
derived from animal or vegetable sources and fuel derived from mineral sources and/or
synthetic sources j(e.g. FT fuels, derived from the Fischer-Tropsch process).
[0069] Preferably the fuel is a blend of a fuel derived from vegetable sources and a fuel
derived from non-vegetable sources; preferably from mineral sources.
[0071] The Bx fuel may contain other flow-improving additives to provide the usual benefits,
in reducing the CP and CFPP. Such compounds may include CFIs and WASAs.
[0073] US 3048479 describes ethylene-vinyl ester pour depressants for middle distillates.
GB 1263152 describes distillate petroleum oil compositions containing ethylene ester copolymers.
The preferred copolymers are of ethylene and vinyl acetate.
US 3961916 describes middle distillate compositions with improved filterability containing mixtures
of two different EVA copolymers.
US 4211534 describes combinations of ethylene polymer, polymer having alkyl side chains, and
nitrogen containing compound to improve cold flow properties of distillate fuel oils.
EP 153176A and
EP 153177A describe polymers or copolymers containing an n-alkyl ester of a mono-ethylenically
unsaturated C4 to C8 mono- or dicarboxylic acid.
[0074] Use of an ethylene vinyl acetate copolymer as a CFI in conjunction with an adduct
of compounds (i) and (ii) as defined herein, is especially preferred.
[0075] The Bx fuel is a low sulphur content fuel, having a sulphur content less than 200
ppm, preferably less than 100 ppm, preferably less than 50 ppm, preferably less than
20 ppm, preferably less than 15 ppm, preferably less than 10 ppm.
[0076] The additive is present in the fuel in an amount (as active material) from 10 mg/kg
fuel, preferably from 20 mg/kg fuel, preferably from 30 mg/kg fuel.
[0077] The additive is present in the fuel in an amount (as active material) up to 200 mg/kg
fuel, preferably up to 100 mg/kg
fuel, preferably up to 80 mg/kg fuel, preferably up to 60 mg/kg fuel, preferably up
to 45 mg/kg fuel.
[0078] The additive may be added to Bx fuel which is known to exhibit a filtration problem
above the cloud point, to reduce the problem or, preferably, to obviate the problem
by preventing precipitation above the cloud point.
[0079] Reducing or solving the problem may be achieved by reducing the size or quantity
of the precipitates which may appear in the Bx fuel above the cloud point, or by controlling
the morphology of the precipitates in the Bx fuel above the cloud point.
[0080] Preferably, however, the additive is added to Bx fuel in order to prevent the emergence
of precipitates above the cloud point. By preventing the emergence of precipitates
above the cloud point we mean that detectable precipitates do not appear in the Bx
fuel under normal storage or use conditions.
[0081] In accordance with some embodiments of the present invention there is provided the
use of an additive which is the reaction product of (i) a compound containing the
segment -NR
1R
2 where R
1 represents a group containing from 4 to 44 carbon atoms and R
2 represents a hydrogen atom or a group R
1, and (ii) a carboxylic acid having from 1 to 4 carboxylic acid groups or an acid
anhydride or acid halide thereof in order to prevent the emergence of precipitates
in the Bx fuel above the cloud point of the Bx fuel.
[0082] The invention will now be further described, by way of example, with reference to
the following test descriptions.
[0083] The invention will now be further described, by way of example, with reference to
the following test descriptions.
Example Set A
[0084] The tests involved using a modified version of the IP387 (Determination of filter
blocking tendency of gas oils and distillate diesel fuels) method.
[0085] In the IP 387 method, a sample of the fuel to be tested is passed at a constant rate
of flow through a glass fibre filter medium. The pressure drop across the filter is
monitored, and the volume of fuel passing the filter medium within a prescribed pressure
drop is measured.
[0086] The filter blocking tendency (FBT) can be described in one of the following ways:
- The pressure drop (P) across a GF/A (glass fibre) filter medium for 300 ml of fuel
to pass at a rate of 20 ml/min is recorded.
- The volume of fuel (v) passed when a pressure of 105kPa is reached. This method of
report is used when less than 300 ml passes at that pressure drop.
[0087] The FBT may be expressed on a single scale by combining these using the following
formulae
[0088] Thus when exactly 300ml passes through the filter at a pressure of 105 kPa, the FBT
is 1.41. Values of FBT >1.41 indicate that less than 300 ml pass through the filter
before a pressure of 105 kPa is reached. Values Of FBT <1.41 indicate that 300ml pass
through the filter at a pressure of less than 105kPa
[0089] An FBT <1.4 is considered to be a good result.
[0090] The modification to the IP 387 method relates to thermal conditioning and cold soak
of a sample being tested.
- 1. the sample is heated to a temperature of 60°C for 3 hours, and then allowed to
cool to 20°C.
- 2. The sample is then cooled to 5°C for 16 hours and then allowed to warm to room
temperature.
Following this conditioning, the Filter Blocking Tendency is determined using IP 387.
[0091] The base fuel used in these tests was a B5 fuel which met the requirements of DIN
EN 590 and contained a commercially available cold flow additive believed to comprise
EVA copolymers in an amount effective to achieve a CFPP of < -15°C. The fuel-had the
following properties:
Method |
Method Number |
Result |
|
|
|
Density at 15°C |
IP 365 |
0.8417g/ml |
CFPP |
IP 309 |
-17°C |
Cloud Point |
ASTM D5772 |
-5.8°C |
|
|
|
Distillation |
JP 123 |
|
IBP |
|
175.5°C |
5% |
|
195.9°C |
10% |
|
206.4°C |
20% |
|
226.0°C |
30% |
|
244.0°C |
40% |
|
260.5°C |
50% |
|
275.0°C |
60% |
|
288.7°C |
70% |
|
302.3°C |
80% |
|
317.2°C |
90% |
|
335.3°C 348,6% |
95% |
|
348.6°C |
FBP |
|
359.5°C |
[0092] Testing was carried out using
- a) this base fuel,
- b) this base fuel additised with 37.5 mg/kg of Compound A, and
- c) this base fuel additised with a commercial WASA (believed to be a nitrogen-containing
polymeric WASA) long used with success to improve the flow properties of mineral diesel
fuels below the cloud point.
[0093] To prepare Compound A phthalic anhydride (7.4g) was mixed with di (hydrogenated tallow)
amine (Commercially available as Armeen 2HT) (50.02g) at a molar ration of 1:2 in
Shellsol AB solvent (57.5g). The reaction mixture was heated at 65°C for approximately
6hours.
The results are as follows:
Sample |
(a) base fuel |
(b) base fuel + 37.5 mg/kg Compound A |
(c) base fuel + 150 mg/kg WASA |
Filter Blocking Tendency |
1.8 |
1.23 |
1.87 |
Initial pressure (kPa) |
10 |
10 |
10 |
Final pressure (kPa) |
105 |
75 |
105 |
Volume filtered (ml) |
200 |
300 |
190 |
Test temperature (°C) |
23 |
23 |
23 |
[0094] Using Compound A allowed tall 300 ml of the fuel to pass through the filter without
the pressure reaching 105 kPa. The improvement over the performance of the base fuel
is very marked. In contrast it is observed that the commercial WASA, at a higher treat
rate, causes no discernable improvement in the flow properties of the base fuel.
Example Set B
[0095] In Example Set B the testing was the same as in Example Set-A but the base fuel ("Basefuel
2") also met the requirements of DIN EN90 and was a B10 fuel prepared from a standard
diesel meeting the specifications of CEC Fuel Specification RF-06-03, blended with
rapeseed methyl ester (RME) and a commercially available cold flow additive believed
to comprise EVA copolymers in an amount effective to achieve a CFPP of < -15ºC.
[0096] The FBT of Basefuel 2 was 2.52.
[0097] The FBT of Basefuel 2 additised with 37.5 mg/kg of Compound A was 1.03.
[0098] The FBT of Basefuel 2 additised with 150 mg/kg of WASA (believed to be a nitrogen-containing
polymeric WASA) was 2.03.
1. Use of
a reaction product of (i) a compound containing the segment -NH1R2 where R1 represents a group containing from 4 to 44 carbon atoms and R2 represents a hydrogen atom or a group R1, and (ii) carboxylic acid having from 1 to 4 carboxylic acid groups or an acid anhydride
or acid halide thereof,
in order to improve the filterability of a Bx fuel above the cloud point of the Bx
fuel;
wherein the Bx fuel comprises fuel derived from animal or vegetable oil sources admixed
with fuel derived from mineral or synthetic sources; wherein the Bx fuel has a sulphur
content less than 200ppm;
wherein the Bx fuel contains at least 4 wt% of fuel derived from animal or vegetable
sources;
and wherein the additive is present in the Bx fuel in an amount (as active material)
of from 10 mg/kg up to 200 mg/kg.
2. Use as claimed in claim 1, wherein the group R1 is a predominantly straight chain, substantially saturated group comprising from
10 to 24 carbon atoms.
3. Use as claimed in claim 1 or 2, in which the group R2 is a group which conforms to the same definitions as are given in any preceding claim
for R1.
4. Use as claimed in claim 3, in which the compound (i) is a secondary amine of formula
HNR1R2 where R1 and R2 are as defined in claim 3; or is an ammonium salt having the cation +NR1H2R3R4 where R1 and R2 are as defined in claim 3 and R3 and R4 independently represent a C(1-4) alkyl group.
5. Use as claimed in any preceding claim, in which the carboxylic acid is selected from
aminoalkylenepolycarboxylic acids, for example nitrilotriacetic acid, propylene diamine
tetraacetic acid, ethylenediamine tetraacetic acid, dialkyl spirobislactones, and
carboxylic acids based on cyclic skeletons, having 5 to 13 carbon atoms in the cyclic
moiety (and their acid anhydrides and acid halides), in which the carboxylic acids
based on cyclic skeletons are preferably selected from pyromellitic acid, cyclohexane-1,2-dicarboxylic
acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalene
dicarboxylic acid, 1,4-dicarboxylic acids and benzene dicarboxylic acids.
6. Use as claimed in claim 5, in which the benzene dicarboxylic acids are selected from
isophthalic acid, terephthalic acid and, especially, phthalic acid (and their acid
anhydrides or acid halides).
7. Use as claimed in any preceding claim, in which the molar ratio of compound (i) to
acid anhydride or acid halide (ii) is such that at least 50% of the acid groups (preferably
at least 75%, preferably at least 90%, and most preferably 100%) are reacted in the
reaction between the compounds (i) and (ii).
8. Use as claimed in any preceding claim, in which compound (i) is a secondary amine
and/or quaternary ammonium salt and compound (ii) is a dicarboxylic acid, or an acid
anhydride or acid halide thereof, wherein the molar ratio of compound(s) (i) to acid,
acid anhydride or acid halide (ii) is at least 1:1, preferably at least 1.5:1, preferably
2:1.
9. Use as claimed in any preceding claim, wherein the said additive is present in the
Bx fuel in an amount of from 5 mg/kg fuel to 500 mg/kg fuel, preferably from 10 mg/kg
fuel to 80 mg/kg fuel, preferably from 20 mg/kg fuel to 60 mg/kg fuel, preferably
from 30 mg/kg fuel to 45 mg/kg fuel.
10. Use as claimed in any preceding claim, in which the Bx fuel is a blended fuel comprising
a fuel component derived from an animal or, preferably, a vegetable oil source and
a fuel component derived from a mineral source.
11. Use as claimed in claim 10, wherein the Bx fuel comprises one or more compounds which
improve the flow properties of the fuel derived from the mineral source at a temperature
below the cloud point of the Bx fuel.
1. Verwendung
eines Reaktionsprodukts von (i) einer Verbindung, die das Segment -NR1R2 enthält, wobei R1 eine Gruppe darstellt, die von 4 bis 44 Kohlenstoffatome enthält, und R2 ein Wasserstoffatom oder eine Gruppe R1 darstellt, und (ii) Carbonsäure mit 1 bis 4 Carbonsäuregruppen oder einem Säureanhydrid
oder Säurehalogenid davon zum Verbessern der Filtrierbarkeit eines Bx-Brennstoffs
über dem Trübungspunkt des Bx-Brennstoffs;
wobei der Bx-Brennstoff Brennstoff abgeleitet aus Tier- oder Pflanzenölquellen gemischt
mit Brennstoff abgeleitet aus mineralischen oder synthetischen Quellen umfasst;
wobei der Bx-Brennstoff einen Schwefelgehalt von weniger als 200 ppm aufweist;
wobei der Bx-Brennstoff wenigstens 4 Gew.-% an Brennstoff abgeleitet aus Tier- oder
Pflanzenquellen enthält;
und wobei der Zusatzstoff in dem Bx-Brennstoff in einer Menge (als aktives Material)
von 10 mg/kg bis 200 mg/kg vorhanden ist.
2. Verwendung gemäß Anspruch 1, wobei die Gruppe R1 eine vorwiegend geradkettige, im Wesentlichen gesättigte Gruppe ist, die 10 bis 24
Kohlenstoffatome umfasst.
3. Verwendung gemäß Anspruch 1 oder 2, wobei die Gruppe R2 eine Gruppe ist, die den gleichen Definitionen, die in einem der vorstehenden Ansprüche
für R1 gegeben werden, entspricht.
4. Verwendung gemäß Anspruch 3, wobei die Verbindung (i) ein sekundäres Amin der Formel
HNR1R2 ist, wobei R1 und R2 wie in Anspruch 3 definiert sind; oder ein Ammoniumsalz mit dem Kation +NR1R2R3R4 ist, wobei R1 und R2 wie in Anspruch 3 definiert sind und R3 und R4 unabhängig eine C(1-4)Alkylgruppe darstellen.
5. Verwendung gemäß einem der vorstehenden Ansprüche, wobei die Carbonsäure ausgewählt
ist aus Aminoalkylenpolycarbonsäuren, beispielsweise Nitrilotriessigsäure, Propylendiamintetraessigsäure,
Ethylendiamintetraessigsäure, Dialkylspirobislactonen und Carbonsäuren auf der Grundlage
von cyclischen Skeletten mit 5 bis 13 Kohlenstoffatomen in der cyclischen Einheit
(und ihren Säureanhydriden und Säurehalogeniden), wobei die Carbonsäuren auf der Grundlage
von cyclischen Skeletten vorzugsweise ausgewählt sind aus Pyromellitsäure, Cyclohexan-1,2-dicarbonsäure,
Cyclohexen-1,2-dicarbonsäure, Cyclopentan-1,2-dicarbonsäure, Naphthalindicarbonsäure,
1,4-Dicarbonsäuren und Benzoldicarbonsäuren.
6. Verwendung gemäß Anspruch 5, wobei die Benzoldicarbonsäuren ausgewählt sind aus Isophthalsäure,
Terephthalsäure und insbesondere Phthalsäure (und ihren Säureanhydriden und Säurehalogeniden).
7. Verwendung gemäß einem der vorstehenden Ansprüche, wobei das Molverhältnis von Verbindung
(i) zu Säureanhydrid oder Säurehalogenid (ii) so ist, dass wenigstens 50 % der Säuregruppen
(vorzugsweise wenigstens 75 %, vorzugsweise wenigstens 90 % und höchst bevorzugt 100
%) bei der Reaktion zwischen den Verbindungen (i) und (ii) umgesetzt werden.
8. Verwendung gemäß einem der vorstehenden Ansprüche, wobei Verbindung (i) ein sekundäres
Amin und/oder quaternäres Ammoniumsalz ist und Verbindung (ii) eine Dicarbonsäure
oder ein Säureanhydrid oder Säurehalogenid davon ist, wobei das Molverhältnis von
Verbindung(en) (i) zu Säure, Säureanhydrid oder Säurehalogenid (ii) wenigstens 1:1
beträgt, vorzugsweise wenigstens 1,5:1, vorzugsweise 2:1.
9. Verwendung gemäß einem der vorstehenden Ansprüche, wobei der Zusatzstoff in dem Bx-Brennstoff
in einer Menge von 5 mg/kg Brennstoff bis 500 mg/kg Brennstoff vorhanden ist, vorzugsweise
von 10 mg/kg Brennstoff bis 80 mg/kg Brennstoff, vorzugsweise von 20 mg/kg Brennstoff
bis 60 mg/kg Brennstoff, vorzugsweise von 30 mg/kg Brennstoff bis 45 mg/kg Brennstoff.
10. Verwendung gemäß einem der vorstehenden Ansprüche, wobei der Bx-Brennstoff ein gemischter
Brennstoff ist, der eine Brennstoffkomponente umfasst, die aus einer Tier- oder vorzugsweise
einer Pflanzenölquelle abgeleitet ist, und eine Brennstoffkomponente, die aus einer
Mineralquelle abgeleitet ist.
11. Verwendung gemäß Anspruch 10, wobei der Bx-Brennstoff eine oder mehrere Verbindungen
umfasst, die die Fließeigenschaften des Brennstoffs abgeleitet aus der Mineralquelle
bei einer Temperatur unter dem Trübungspunkt des Bx-Brennstoffs verbessern.
1. Utilisation d'un produit de la réaction de (i) un composé contenant le segment -NR1R2 où R1 représente un groupe contenant de 4 à 44 atomes de carbone et R2 représente un atome d'hydrogène ou un groupe R1, et (ii) un acide carboxylique ayant de 1 à 4 groupes acide carboxylique ou un anhydride
d'acide ou un halogénure d'acide de celui-ci,
afin d'améliorer la filtrabilité d'un carburant Bx au-delà du point de trouble du
carburant Bx ;
dans laquelle le carburant Bx comprend du carburant dérivé de sources huileuses animales
ou végétales mélangées avec du carburant dérivé de sources minérales ou synthétiques
;
dans laquelle le carburant Bx a une teneur en soufre inférieure à 200 ppm ;
dans laquelle le carburant Bx contient au moins 4 % en poids de carburant dérivé de
sources animales ou végétales ;
et dans laquelle l'additif est présent dans le carburant Bx en une quantité (sous
forme de matériau actif) de 10 mg/kg jusqu'à 200 mg/kg.
2. Utilisation selon la revendication 1, dans laquelle le groupe R1 est un groupe pratiquement saturé principalement à chaîne droite comprenant de 10
à 24 atomes de carbone.
3. Utilisation selon la revendication 1 ou 2, dans laquelle le groupe R2 est un groupe qui se conforme aux mêmes définitions que celles indiquées à propos
de R1 dans l'une quelconque des revendications précédentes.
4. Utilisation selon la revendication 3, dans laquelle le composé (i) est une amine secondaire
de formule HNR1R2 où R1 et R2 sont tels que définis dans la revendication 3 ; ou est un sel d'ammonium ayant le
cation +NR1R2R3R4 où R1 et R2 sont tels que définis dans la revendication 3 et R3 et R4 représentent indépendamment un groupe alkyle en C1 à C4.
5. Utilisation selon l'une quelconque des revendications précédentes, dans laquelle l'acide
carboxylique est choisi parmi les acides aminoalkylènepolycarboxyliques, par exemple
l'acide nitrilotriacétique, l'acide propylènediamine-tétraacétique, l'acide éthylènediaminetétraacétique,
les dialkylspirobislactones, et les acides carboxyliques basés sur des charpentes
cycliques, ayant 5 à 13 atomes de carbone dans le fragment cyclique (et leurs anhydrides
d'acide et halogénures d'acide), et dans laquelle les acides carboxyliques basés sur
des charpentes cycliques sont de préférence choisis parmi l'acide pyromellitique,
l'acide cyclohexane-1,2-dicarboxylique, l'acide cyclohexène-1,2-dicarboxylique, l'acide
cyclopentane-1,2-dicarboxylique, l'acide naphtalènedicarboxylique, les acides 1,4-dicarboxyliques
et les acides benzènedicarboxyliques.
6. Utilisation selon la revendication 5, dans laquelle les acides benzènedicarboxyliques
sont choisis parmi l'acide isophtalique, l'acide téréphtalique, et en particulier
l'acide phtalique (et leurs anhydrides d'acide ou halogénures d'acide).
7. Utilisation selon l'une quelconque des revendications précédentes, dans laquelle le
rapport molaire du composé (i) à l'anhydride d'acide ou à l'halogénure d'acide (ii)
est tel qu'au moins 50 % des groupes acides (de préférence au moins 75 %, de préférence
au moins 90 %, et tout spécialement 100 %) réagissent dans la réaction entre les composés
(i) et (ii).
8. Utilisation selon l'une quelconque des revendications précédentes, dans laquelle le
composé (i) est un sel d'amine secondaire et/ou d'ammonium quaternaire et le composé
(ii) est un acide dicarboxylique, ou un anhydride d'acide ou halogénure d'acide de
celui-ci, et dans laquelle le rapport molaire du ou des composés (i) à l'acide, l'anhydride
d'acide ou l'halogénure d'acide (ii) est d'au moins 1/1, de préférence d'au moins
1,5/1, de préférence de 2/1.
9. Utilisation selon l'une quelconque des revendications précédentes, dans laquelle ledit
additif est présent dans le carburant Bx en une quantité de 5 mg par kg de carburant
à 500 mg par kg de carburant, de préférence de 10 mg par kg de carburant à 80 mg par
kg de carburant, de préférence de 20 mg par kg de carburant à 60 mg par kg de carburant,
de préférence de 30 mg par kg de carburant à 45 mg par kg de carburant.
10. Utilisation selon l'une quelconque des revendications précédentes, dans laquelle le
carburant Bx est un carburant mixte comprenant un composant carburant dérivé d'une
source huileuse animale ou de préférence végétale et un composant carburant dérivé
d'une source minérale.
11. Utilisation selon la revendication 10, dans laquelle le carburant Bx comprend un ou
plusieurs composés qui améliorent les propriétés d'écoulement du carburant dérivé
de la source minérale à une température inférieure au point de trouble du carburant
Bx.