U.S. patent application number 15/980151 was filed with the patent office on 2018-09-13 for fuels derived from animal or vegetable oil sources.
This patent application is currently assigned to Innospec Limited. The applicant listed for this patent is Innospec Limited. Invention is credited to Andrea Sneddon.
Application Number | 20180258358 15/980151 |
Document ID | / |
Family ID | 40469724 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180258358 |
Kind Code |
A1 |
Sneddon; Andrea |
September 13, 2018 |
FUELS DERIVED FROM ANIMAL OR VEGETABLE OIL SOURCES
Abstract
There is provided a method of providing an improved biofuel, by
the presence of an additive which is the reaction product of (i) a
compound containing the segment --NR.sup.1R.sup.2 where R.sup.1
represents a group containing from 4 to 44 carbon atoms and R.sup.2
represents a hydrogen atom or a group R.sup.1 (for example
di-hydrogenated tallow amine) and (ii) a carboxylic acid having
from 1 to 4 carboxylic acid groups or an acid anhydride or acid
chloride thereof (for example phthalic acid or phthalic anhydride).
The additives described combat problems arising from precipitation
at temperatures above the cloud point.
Inventors: |
Sneddon; Andrea; (Heswall,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Innospec Limited |
Ellesmere Port |
|
GB |
|
|
Assignee: |
Innospec Limited
Ellesmere Port
GB
|
Family ID: |
40469724 |
Appl. No.: |
15/980151 |
Filed: |
May 15, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13148607 |
Sep 16, 2011 |
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PCT/GB2010/050169 |
Feb 4, 2010 |
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15980151 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10L 1/221 20130101;
C10L 1/143 20130101; C10L 1/1616 20130101; C10L 1/224 20130101;
C10L 10/14 20130101; C10L 1/19 20130101; C10L 1/1973 20130101 |
International
Class: |
C10L 1/22 20060101
C10L001/22; C10L 10/14 20060101 C10L010/14; C10L 1/224 20060101
C10L001/224; C10L 1/14 20060101 C10L001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2009 |
GB |
0902009.0 |
Claims
1-16. (canceled)
17. A method of improving the filterability of a Bx fuel above the
cloud point of the Bx fuel the method comprising adding to the fuel
an additive which is the reaction product of (i) a compound
containing the segment --NR.sup.1R.sup.2 where R.sup.1 represents a
group containing from 4 to 44 carbon atoms and R.sup.2 represents a
hydrogen atom or a group R.sup.1, and (ii) a carboxylic acid having
from 1 to 4 carboxylic acid groups or an acid anhydride or acid
halide thereof; wherein the group R.sup.1 is a predominantly
straight chain, substantially saturated hydrocarbyl group
comprising from 10 to 24 carbon atoms; and the carboxylic acid is
an optionally substituted benzene dicarboxylic acid.
18. A method as claimed in claim 1, in which the group R.sup.2 is a
group which conforms to the same definitions as are given for
R.sup.1.
19. A method as claimed in claim 2, in which the compound (i) is a
secondary amine of formula HNR.sup.1R.sup.2 where R.sup.1 and
R.sup.2 are as defined in claim 2; or is an ammonium salt having
the cation +NR.sup.1R.sup.2R.sup.3R.sup.4 where R.sup.1 and R.sup.2
are as defined in claim 2 and R.sup.3 and R.sup.4 independently
represent a C(1-4) alkyl group.
20. A method as claimed in claim 1, in which the benzene
dicarboxylic acids are selected from isophthalic acid, terephthalic
acid and, especially, phthalic acid (and their acid anhydrides or
acid halides).
21. A method as claimed in claim 1, 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).
22. A method as claimed in claim 1, 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.
23. A method as claimed in claim 1, 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.
24. A method as claimed in claim 1, 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.
25. A method as claimed in claim 8, 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.
Description
[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 85 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 (.DELTA.CP, .DELTA.PP, .DELTA.CFPP). 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] 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.
[0016] 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.
[0017] 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.degree. C., compared with corresponding fuels without
additives.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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 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.
[0023] 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.
[0024] 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.
[0025] In accordance with a first aspect of the present invention
there is provided a method of providing an improved Bx fuel, by the
presence of an additive which is the reaction product of (i) a
compound containing the segment --NR.sup.1R.sup.2 where R.sup.1
represents a group containing from 4 to 44 carbon atoms and R.sup.2
represents a hydrogen atom or a group R.sup.1, and (ii) a
carboxylic acid having from 1 to 4 carboxylic acid groups or an
acid anhydride or acid halide thereof. Preferably R.sup.1 is a
hydrocarbyl group or a polyethoxylate or polypropoxylate group.
[0026] Preferably the group R.sup.1 is a hydrocarbyl group.
Preferably the group R.sup.1 is predominantly a straight chain
group.
[0027] 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.sup.1 is an organic group entirely
predominantly containing carbon and hydrogen atoms.
[0028] A hydrocarbyl group R.sup.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.sup.1 having from 4 to 10 carbon atom it may contain one
unsaturated bond. In the case of a hydrocarbyl group R.sup.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.sup.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.sup.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.sup.1 having from 41 up to 44 carbon
atom it may contain up to five unsaturated bonds. Preferably,
however, a hydrocarbyl group R.sup.1 is preferably a fully
saturated alkyl group, preferably a fully saturated n-alkyl
group.
[0029] Preferably a group R.sup.1 comprises from 6 to 36 carbon
atoms, preferably 8 to 32, preferably 10 to 24, preferably 12 to
22, most preferably 14 to 20.
[0030] It will be appreciated that the group R.sup.1 will typically
include moieties with a range of carbon atoms. The definitions
C.sub.4-44 . . . C.sub.14-22 are not intended to denote that all
R.sup.1 groups must fall within the stated range.
[0031] The group R.sup.2, when present, preferably conforms to the
same definitions as are given for R.sup.1. R.sup.1 and R.sup.2 need
not be the same. Preferably, however, R.sup.1 and R.sup.2 are the
same.
[0032] Preferably the species (ii) is a carboxylic acid or an acid
anhydride thereof.
[0033] However if an acid halide is used it is preferably an acid
chloride.
[0034] Suitable compounds (i) include primary, secondary, tertiary
and quaternary amines. Tertiary and quaternary amines only form
amine salts.
[0035] Secondary amines, of formula HNR.sup.1R.sup.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.sub.14, 30-32% wt
C.sub.16, and 58-60% wt C.sub.18.
[0036] Quaternary amines, of formula
[+NR.sup.1R.sup.2R.sup.3R.sup.4--An], are an especially preferred
class of compounds (i). R.sup.1 and R.sup.2 are as defined above
(but R.sup.2 is not hydrogen). R.sup.3 and R.sup.4 independently
represent a C(1-4) alkyl group, preferably propyl, ethyl or, most
preferably, methyl. +NR.sup.1R.sup.2(CH.sub.3).sub.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 may
be 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.
[0037] Also preferred are mixtures of primary and secondary amines,
as species (i).
[0038] Also preferred are mixtures of secondary and quaternary
amines, as species (ii).
[0039] Preferred carboxylic acids include carboxylic acids
containing two, three or four carboxylic acid groups, and acid
anhydrides and acid halides thereof.
[0040] Examples of suitable carboxylic acids and their anhydrides
include aminoalkylenepolycarboxylic acids, for example
nitrilotriacetic acid, propylene diamine tetraacetic acid,
ethylenediamine tetraacetic acid, and carboxylic acids based on
cyclic skeletons, e.g., pyromellitic acid,
cyclohexane-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.sup.3R.sup.4 where R.sup.3 and
R.sup.1 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.
[0041] 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.
[0042] 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. EDCI). 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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, 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).
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] Another preferred additive is the reaction product of one
mole of alkyispirobislactone, for example dodecenyl-spirobislactone
with one mole of mono-tallow amine and one mole of di-tallow
amine.
[0055] The fuel composition of the present invention may contain at
least 1 wt % of fuel derived from animal or vegetable sources, for
example at least 2 wt %, at least 3 wt %, at least 4 wt %, 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.
[0056] 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.
[0057] 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, diacyiglycerols,
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.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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.
[0062] Preferably the Bx fuel is a middle distillate fuel,
generally boiling within the range of from 110 to 500, e.g. 150 to
400.degree. C. Preferably it is a Bx fuel for use in diesel engines
or heating fuel oil.
[0063] 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
(e.g. FT fuels, derived from the Fischer-Tropsch process).
[0064] 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. 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.
[0065] Examples of such additives and their use in petroleum-based
oils are described in U.S. Pat. No. 3,048,479; GB 1263152; U.S.
Pat. No. 3,961,916; U.S. Pat. No. 4,211,534; EP 153176A; and EP
153177A.
[0066] U.S. Pat. No. 3,048,479 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. U.S.
Pat. No. 3,961,916 describes middle distillate compositions with
improved filterability containing mixtures of two different EVA
copolymers. U.S. Pat. No. 4,211,534 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.
[0067] 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.
[0068] Preferably the Bx fuel is a low sulphur content fuel,
preferably 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.
[0069] Preferably the additive is present in the fuel in an amount
(as active material) of from 5 mg/kg fuel, preferably from 10 mg/kg
fuel, preferably from 20 mg/kg fuel, preferably from 30 mg/kg
fuel.
[0070] Preferably the additive is present in the fuel in an amount
(as active material) up to 500 mg/kg, preferably 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.
[0071] 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.
[0072] 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.
[0073] 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.
[0074] In accordance with a second aspect 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.sup.1R.sup.2
where R.sup.1 represents a group containing from 4 to 44 carbon
atoms and R.sup.2 represents a hydrogen atom or a group R.sup.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
maintain the filterability of the Bx fuel above the cloud point of
the Bx fuel.
[0075] In accordance with a third aspect 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.sup.1R.sup.2
where R.sup.1 represents a group containing from 4 to 44 carbon
atoms and R.sup.2 represents a hydrogen atom or a group R.sup.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.
[0076] Aspects and preferred features described above following
presentation of the first aspect apply also to the second aspect
and third aspect, including: ways in which filterability may be
maintained; ways in which precipitation may be controlled,
inhibited or prevented; preferred compounds (i) and (ii); preferred
ratios of (I) to (II); preferred Bx fuels; and preferred
concentrations of the additive in the Bx fuel.
[0077] In accordance with a fourth aspect of the present invention
there is provided a Bx fuel having improved flow properties above
the cloud point of the Bx fuel, the fuel comprising an additive
which is the reaction product of (i) a compound containing the
segment --NR.sup.1R.sup.2 where R.sup.1 represents a group
containing from 4 to 44 carbon atoms and R.sup.2 represents a
hydrogen atom or a group R.sup.1, and (ii) carboxylic acid having
from 1 to 4 carboxylic acid groups or an acid anhydride or acid
halide thereof.
[0078] In accordance with a fifth aspect of the present invention
there is provided an additive composition comprising an additive
which is the reaction product of (i) a compound containing the
segment --NR.sup.1R.sup.2 where R.sup.1 represents a group
containing from 4 to 44 carbon atoms and R.sup.2 represents a
hydrogen atom or a group R.sup.1, and (ii) a carboxylic acid having
from 1 to 4 carboxylic acid groups or an acid anhydride thereof in
a solvent.
[0079] In accordance with a sixth aspect of the present invention
there is provided a method of improving the filter blocking
tendency of a Bx fuel by addition of an additive as defined in any
preceding claim.
[0080] The invention will now be further described, by way of
example, with reference to the following test descriptions.
EXAMPLE SET A
[0081] The tests involved using a modified version of the IP387
(Determination of filter blocking tendency of gas oils and
distillate diesel fuels) method.
[0082] 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.
[0083] The filter blocking tendency (FBT) can be described in one
of the following ways: [0084] 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. [0085] The volume of fuel (v) passed when a
pressure of 105 kPa is reached. This method of report is used when
less than 300 ml passes at that pressure drop.
[0086] The FBT may be expressed on a single scale by combining
these using the following formulae
F B T = 1 + ( P 105 ) 2 and F B T = 1 + ( 300 V ) 2
##EQU00001##
[0087] Thus when exactly 300 ml 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
300 ml pass through the filter at a pressure of less than 105
kPa
[0088] An FBT<1.4 is considered to be a good result.
[0089] The modification to the IP 387 method relates to thermal
conditioning and cold soak of a sample being tested. [0090] 1. the
sample is heated to a temperature of 60.degree. C. for 3 hours and
then allowed to cool to 20.degree. C. [0091] 2. The sample is then
cooled to 5.degree. C. for 16 hours and then allowed to warm to
room temperature.
[0092] Following this conditioning, the Filter Blocking Tendency is
determined using IP 387.
[0093] The base fuel used in these tests was a 85 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.degree. C. The
fuel had the following properties:
TABLE-US-00001 Method Method Number Result Density at IP 365 0.8417
g/ml 15.degree. C. CFPP IP 309 -17.degree. C. Cloud Point ASTM
D5772 -5.8.degree. C. Distillation IP 123 IBP 175.5.degree. C. 5%
195.9.degree. C. 10% 206.4.degree. C. 20% 226.0.degree. C. 30%
244.0.degree. C. 40% 260.5.degree. C. 50% 275.0.degree. C. 60%
288.7.degree. C. 70% 302.3.degree. C. 80% 317.2.degree. C. 90%
335.3.degree. C. 95% 348.6.degree. C. FBP 359.5.degree. C.
[0094] 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.
[0095] To prepare Compound A phthalic anhydride (7.4 g) was mixed
with di (hydrogenated tallow) amine (Commercially available as
Armeen 2HT) (50.02 g) at a molar ration of 1:2 in Shellsol AB
solvent (57.5 g). The reaction mixture was heated at 65.degree. C.
for approximately 6 hours.
[0096] The results are as follows:
TABLE-US-00002 (b) base fuel + (c) base fuel + 37.5 mg/kg 150 mg/kg
Sample (a) base fuel Compound A 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 (.degree.
C.) 23 23 23
[0097] Using Compound A allowed all 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
[0098] 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 <-15.degree. C.
[0099] The FBT of Basefuel 2 was 2.52.
[0100] The FBT of Basefuel 2 additised with 37.5 mg/kg of Compound
A was 1.03.
[0101] The FBT of Basefuel 2 additised with 150 mg/kg of WASA
(believed to be a nitrogen-containing polymeric WASA) was 2.03.
* * * * *