U.S. patent application number 13/315468 was filed with the patent office on 2012-06-14 for use of mixtures of monocarboxylic acids and polycyclic hydrocarbon compounds for increasing the cetane number of fuel oils.
This patent application is currently assigned to BASF SE. Invention is credited to Harald Bohnke.
Application Number | 20120144731 13/315468 |
Document ID | / |
Family ID | 46197925 |
Filed Date | 2012-06-14 |
United States Patent
Application |
20120144731 |
Kind Code |
A1 |
Bohnke; Harald |
June 14, 2012 |
USE OF MIXTURES OF MONOCARBOXYLIC ACIDS AND POLYCYCLIC HYDROCARBON
COMPOUNDS FOR INCREASING THE CETANE NUMBER OF FUEL OILS
Abstract
The use of mixtures of (A) aliphatic saturated or unsaturated
monocarboxylic acids having 12 to 24 carbon atoms or the
dimerization or trimerization products thereof, which may be
present in the form of free carboxylic acids and/or in the form of
ammonium salts, amides, esters and/or nitriles, and (B) polycyclic
hydrocarbon compounds which are obtainable from distillation
residues of natural oils, which have been extracted from tree
resins, for increasing the cetane number of fuel oils which
comprise at least one additive with detergent action and at least
one cetane number improver, the mixtures of components (A) and (B)
being used in a concentration of 10 to 500 ppm by weight, based on
the total amount of the fuel oil.
Inventors: |
Bohnke; Harald; (Mannheim,
DE) |
Assignee: |
BASF SE
Ludwigshafen
DE
|
Family ID: |
46197925 |
Appl. No.: |
13/315468 |
Filed: |
December 9, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61422668 |
Dec 14, 2010 |
|
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Current U.S.
Class: |
44/307 ; 44/326;
44/334; 44/347; 44/351; 44/385; 44/386; 44/388 |
Current CPC
Class: |
C10L 1/1881 20130101;
C10L 1/2383 20130101; C10L 10/12 20130101; C10L 1/143 20130101;
C10L 1/231 20130101; C10L 1/1883 20130101; C10L 1/19 20130101; C10L
1/224 20130101; C10L 1/1888 20130101; C10L 1/1905 20130101; C10L
1/1885 20130101; C10L 1/2286 20130101 |
Class at
Publication: |
44/307 ; 44/385;
44/351; 44/334; 44/386; 44/326; 44/347; 44/388 |
International
Class: |
C10L 1/188 20060101
C10L001/188; C10L 1/19 20060101 C10L001/19; C10L 1/23 20060101
C10L001/23; C10L 1/232 20060101 C10L001/232; C10L 1/233 20060101
C10L001/233; C10L 1/224 20060101 C10L001/224 |
Claims
1. The use of mixtures of A) aliphatic saturated or unsaturated
monocarboxylic acids having 12 to 24 carbon atoms or the
dimerization or trimerization products thereof, which may be
present in the form of free carboxylic acids and/or in the form of
ammonium salts, amides, esters and/or nitriles, and B) polycyclic
hydrocarbon compounds which are obtainable from distillation
residues of natural oils, which have been extracted from tree
resins, for increasing the cetane number of fuel oils which
comprise at least one additive with detergent action and at least
one cetane number improver, the mixtures of components (A) and (B)
being used in a concentration of 10 to 500 ppm by weight, based on
the total amount of the fuel oil.
2. The use according to claim 1, in which the fuel oils comprise at
least one additive with detergent action which is selected from (i)
compounds with moieties derived from succinic anhydride and having
hydroxyl and/or amino and/or amido and/or imido groups; (ii)
nitrogen compounds quaternized in an acid-free manner, obtainable
by addition of a compound comprising at least one oxygen- or
nitrogen-containing group reactive with an anhydride and
additionally at least one quaternizable amino group onto a
polycarboxylic anhydride compound and subsequent quaternization;
(iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines.
3. The use according to claim 2, in which the fuel oils comprise at
least one polyisobutenyl-substituted succinimide as an additive
with detergent action.
4. The use according to claims 1 to 3, in which the fuel oils
comprise 2-ethylhexyl nitrate as a cetane number improver.
5. The use according to claims 1 to 4, in which the carboxylic
acids (A) and the polycyclic hydrocarbon compounds (B) are present
in the mixtures in a weight ratio relative to one another of 65 to
99.9:0.1 to 35, especially of 90 to 99.9:0.1 to 10.
6. The use according to claims 1 to 5, in which the mixtures of
carboxylic acids (A) and polycyclic hydrocarbon compounds (B) used
are tall oil fatty acid or dimerized tall oil fatty acid.
7. The use according to claims 1 to 6 for use in fuel oils, which
consist (a) to an extent of 0.1 to 100% by weight of at least one
biofuel oil based on fatty acid esters, and (b) to an extent of 0
to 99.9% by weight of middle distillates of fossil origin and/or of
vegetable and/or animal origin, which are essentially hydrocarbon
mixtures and are free of fatty acid esters.
8. The use according to claims 1 to 6 for use in fuel oils which
have at least one of the following properties: (.alpha.) a sulfur
content of less than 50 mg/kg; (.beta.) a maximum content of 8% by
weight of polycyclic aromatic hydrocarbons; (.gamma.) a 95%
distillation point (vol/vol) at not more than 360.degree. C.
Description
[0001] The present invention relates to the use of mixtures of
aliphatic saturated or unsaturated, relatively long-chain
monocarboxylic acids or derivatives thereof and polycyclic
hydrocarbon compounds for increasing the cetane number of fuel oils
which comprise at least one additive with detergent action and at
least one cetane number improver.
[0002] Fuel oils generally comprise cetane number improvers, which
are also referred to as ignition accelerators or combustion
improvers. For this purpose, typically organic nitrates are used,
which have been known for some time as cetane number improvers in
fuel oils or middle distillates such as diesel fuels, and have also
been used therein.
[0003] Higher cetane numbers lead to more rapid engine starts,
especially in cold weather, to lower engine noise, to more complete
combustion, to less evolution of smoke and, under some
circumstances, to lower injector carbonization.
[0004] Typical organic nitrates which are suitable as cetane number
improvers in fuel oils, especially in diesel fuels, are nitrates of
short- and medium-chain, linear and branched alkanols and nitrates
of cycloalkanols, such as n-hexyl nitrate, 2-ethyl-hexyl nitrate,
n-heptyl nitrate, n-octyl nitrate, isooctyl nitrate, sec-octyl
nitrate, n-nonyl nitrate, n-decyl nitrate, n-dodecyl nitrate,
cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate
and isopropylcyclohexyl nitrate. Specific branched decyl nitrates
of the formula R.sup.1R.sup.2CH--CH.sub.2--O--NO.sub.2 in which
R.sup.1 denotes an n-propyl or isopropyl radical and R.sup.2 a
linear or branched alkyl radical having 5 carbon atoms are also
recommended in WO 2008/092809 as combustion improvers or cetane
number improvers. However, the most commercially important cetane
number improver is 2-ethylhexyl nitrate.
[0005] However, the prior art cetane number improvers mentioned are
still in need of improvement in terms of action. It was thus an
object of the present invention to increase the cetane number of
fuel oils, especially of diesel fuels and of mixtures of biofuel
oils and middle distillates of fossil, vegetable or animal origin,
by a suitable measure.
[0006] Accordingly the use has been found of mixtures of [0007] (A)
aliphatic saturated or unsaturated monocarboxylic acids having 12
to 24 carbon atoms or the dimerization or trimerization products
thereof, which may be present in the form of free carboxylic acids
and/or in the form of ammonium salts, amides, esters and/or
nitriles, and [0008] (B) polycyclic hydrocarbon compounds which are
obtainable from distillation residues of natural oils, which have
been extracted from tree resins, for increasing the cetane number
of fuel oils which comprise at least one additive with detergent
action and at least one cetane number improver, the mixtures of
components (A) and (B) being used in a concentration of 10 to 500
ppm by weight, based on the total amount of the fuel oil.
[0009] This mixture of components (A) and (B) in fuel oils in the
presence of customary amounts of cetane number improvers and
additives with detergent action increases the cetane number
(determined to the standard EN ISO 5165) generally by at least 1.0
unit, usually even by at least 1.5 units, compared to the fuel oil
without cetane number improver and without additives with detergent
action. The corresponding increase in the cetane number (determined
to the standard EN ISO 5165) is generally at least 0.5 unit
compared to the fuel oil containing the same amount of cetane
number improver and the same amount of additives with detergent
action. The mixture of components (A) and (B), together with the
cetane number improver, brings about a synergistic increase in the
cetane number.
[0010] Mixtures of said saturated or unsaturated monocarboxylic
acids having 12 to 24 carbon atoms or the dimerization or
trimerization products thereof (A) and said polycyclic carbon
compounds (B), which are obtainable from distillation residues of
natural oils which have been extracted from tree resins, are
described in WO 2007/082825 for improvement of the storage
stability of fuel additive concentrates which comprise at least one
detergent and at least one cetane number improver.
[0011] Component (A) in the mixtures mentioned comprises preferably
aliphatic saturated or unsaturated monocarboxylic acids having 14
to 20 carbon atoms, especially 16 to 18 carbon atoms. These
monocarboxylic acids are generally linear. Useful for component (A)
are especially naturally occurring fatty acids, in particular those
having 14 to 20 carbon atoms, especially 16 to 18 carbon atoms.
Typical representatives of such monocarboxylic acids or fatty acids
are lauric acid, myristic acid, palmitic acid, stearic acid, oleic
acid, linoleic acid, linolenic acid and elaidic acid. Component (A)
may consist only of one such monocarboxylic acid or fatty acid or
preferably of a mixture of two or more such monocarboxylic acids or
fatty acids. In the case of naturally occurring fatty acids, as
obtained, for example, from rapeseed oil, soybean oil or tall oil,
these are generally mixtures of several such monocarboxylic
acids.
[0012] Component (B), which naturally originates from tree resins,
especially conifer resins from pines or spruces, is formed from one
or preferably more than one so-called resin acid. Resin acids are
carboxyl-containing polycyclic hydrocarbon compounds. They include,
as the most important representatives, abietic acid, dehydroabietic
acid, dihydroabietic acid, tetrahydroabietic acid, neoabietic acid,
palustric acid, pimaric acid, isopimaric acid and levopimaric acid.
These resin acids may partly also be present in oxidized form as
so-called oxy acids.
[0013] In a preferred embodiment, components (A) and (B) are used
in the mixtures to be used in accordance with the invention in a
weight ratio of 65 to 99.9:0.1 to 35, especially of 90 to 99.9:0.1
to 10, in particular of 97 to 99.9:0.1 to 3.
[0014] Particularly suitable mixtures of components (A) and (B) are
those of tall oil fatty acid and dimerized tall oil fatty acid.
Tall oil fatty acid is produced from tall oil, which is obtained by
digestion of resin-rich wood types, especially of spruce or pine
wood. Tall oil fatty acid is a mixture of fatty acids in which the
C.sub.18-unsaturated monocarboxylic acids, in particular oleic
acid, linoleic acid and conjugated C.sub.18 fatty acids, and also
5,9,12-octadecatrienoic acid, predominate, resin acids and
optionally oxyacids (i.e. oxidized fatty acids and resin acids).
Resin acids are so-called tall resin, in which abietic acid,
dehydroabietic acid and palustric acid predominate, and smaller
proportions of dihydroabietic acid, neoabietic acid, pimaric acid
and isopimaric acid can be found as well as further resin acids. In
the best tall oil fatty acid quality, the fatty acid content is at
least 97% by weight and the tall resin content is up to 3% by
weight.
[0015] The recovery of tall oil fatty acid and resin acids from
resin trees by digestion, extraction and distillation processes is
known to those skilled it the art and therefore need not be
explained any further here.
[0016] In dimerized tall oil fatty acid, the fatty acid component
(A) is present in dimerized form. Dimerizations and trimerizations
of monocarboxylic acids or fatty acids can be performed by
processes customary for this purpose and are known in principle to
those skilled in the art.
[0017] The monocarboxylic acids or fatty acids and their
dimerization or trimerization products of component (A) may be
present as free carboxylic acids and/or as ammonium salts, for
example as NH.sub.4 salts or substituted ammonium salts such as
mono-, di-, tri- or tetramethylammonium salts, and/or in the form
of amides, esters or nitriles. Amide structures typical thereof
have the --CO--NH.sub.2, --CO--NH-alkyl or --CO--N(alkyl).sub.2
moieties, where "alkyl" here represents especially C.sub.1- to
C.sub.4-alkyl radicals such as methyl or ethyl. Ester structures
typically include C.sub.1- to C.sub.4-alkanol ester radicals such
as methyl or ethyl ester radicals.
[0018] Additives with detergent action refer, in the context of the
present invention to those compounds whose effect in an internal
combustion engine, especially a diesel engine, consists
predominantly or at least essentially of eliminating and/or
preventing deposits. The detergents are preferably amphiphilic
substances which have at least one hydrophobic hydrocarbyl radical
having a number-average molecular weight (M.sub.n) of 85 to 20 000,
especially of 300 to 5000, and in particular of 500 to 2500, and at
least one polar moiety.
[0019] In a preferred embodiment, the fuel oils comprise at least
one additive with detergent action which is selected from [0020]
(i) compounds with moieties derived from succinic anhydride and
having hydroxyl and/or amino and/or amido and/or imido groups;
[0021] (ii) nitrogen compounds quaternized in an acid-free manner,
obtainable by addition of a compound comprising at least one
oxygen- or nitrogen-containing group reactive with an anhydride and
additionally at least one quaternizable amino group onto a
polycarboxylic anhydride compound and subsequent quaternization;
[0022] (iii) polytetrahydrobenzoxazines and
bistetrahydrobenzoxazines.
[0023] Additives comprising moieties deriving from succinic
anhydride and having hydroxyl and/or amino and/or amido and/or
imido groups are preferably corresponding derivatives of
polyisobutenylsuccinic anhydride, which are obtainable by reaction
of conventional or high-reactivity polyisobutene with M.sub.n=300
to 5000, in particular with M.sub.n=500 to 2500, with maleic
anhydride by a thermal route or via the chlorinated polyisobutene.
Of particular interest in this context are derivatives with
aliphatic polyamines such as ethylenediamine, diethylenetriamine,
triethylenetetramine or tetraethylenepentamine. The moieties with
hydroxyl and/or amino and/or amido and/or imido groups are for
example carboxylic acid groups, acid amides, acid amides of di- or
polyamines, which, as well as the amide function, also have free
amine groups, succinic acid derivatives with an acid and an amide
function, carboxymides with monoamines, carboxymides with di- or
polyamines, which, as well as the imide function, also have free
amine groups, and diimides, which are formed by the reaction of di-
or polyamines with two succinic acid derivatives. Such fuel
additives are described especially in U.S. Pat. No. 4,849,572.
[0024] Nitrogen compounds quaternized in an acid-free manner
according to the above group (ii), which are obtainable by addition
of a compound which comprises at least one oxygen- or
nitrogen-containing group reactive with an anhydride and
additionally at least one quaternizable amino group onto a
polycarboxylic anhydride compound and subsequent quaternization,
especially with an epoxide in the absence of free acid, are
described in EP patent application 10 168 622.8. Suitable compounds
having at least one oxygen- or nitrogen-containing group reactive
with anhydride and additionally at least one quaternizable amino
group are especially polyamines having at least one primary or
secondary amino group and at least one tertiary amino group. Useful
polycarboxylic anhydrides are especially dicarboxylic acids such as
succinic acid, having a relatively long-chain hydrocarbyl
substituent, preferably having a number-average molecular weight
M.sub.n for the hydrocarbyl substituent of 200 to 10 000, in
particular of 350 to 5000. Such a quaternized nitrogen compound is,
for example, the reaction product, obtained at 40.degree. C., of
polyisobutenylsuccinic anhydride, in which the polyisobutenyl
radical typically has an M.sub.n of 1000, with
3-(dimethylamino)propylamine, which constitutes a
polyisobutenylsuccinic monoamide and which is subsequently
quaternized with styrene oxide in the absence of free acid at
70.degree. C.
[0025] Polytetrahydrobenzoxazines and bistetrahydrobenzoxazines
according to the above group (iii) are described in EP patent
application 10 194 307.4. Such polytetrahydrobenzoxazines and
bistetrahydrobenzoxazines are obtainable by successively reacting,
in a first reaction step, a C.sub.1- to C.sub.20-alkylenediamine
having two primary amino functions, e.g. 1,2-ethylenediamine, with
a C.sub.1- to C.sub.12-aldehyde, e.g. formaldehyde, and a C.sub.1-
to C.sub.8-alkanol at a temperature of 20 to 80.degree. C. with
elimination and removal of water, where both the aldehyde and the
alcohol can each be used in more than twice the molar amount,
especially in each case in 4 times the molar amount, relative to
the diamine, in a second reaction step reacting the condensation
product thus obtained with a phenol which bears at least one
long-chain substituent having 6 to 3000 carbon atoms, e.g. a
tert-octyl, n-nonyl, n-dodecyl or polyisobutyl radical having an
M.sub.n of 1000, in a stoichiometric ratio relative to the
originally used alkylenediamine of 1.2:1 to 3:1 at a temperature of
30 to 120.degree. C. and optionally in a third reaction step
heating the bistetrahydrobenzoxazine thus obtained to a temperature
of 125 to 280.degree. C. for at least 10 minutes.
[0026] The at least one additive with detergent action used for the
present invention is more preferably a compound from group (i),
which is a polyisobutenyl-substituted succinimide.
[0027] Cetane number improvers used are typically organic nitrates.
Such organic nitrates are especially nitrate esters of
unsubstituted or substituted aliphatic or cycloaliphatic alcohols,
usually having up to about 10, in particular having 2 to 10 carbon
atoms. The alkyl group in these nitrate esters may be linear or
branched, and saturated or unsaturated. Typical examples of such
nitrate esters are methyl nitrate, ethyl nitrate, n-propyl nitrate,
isopropyl nitrate, allyl nitrate, n-butyl nitrate, isobutyl
nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate,
isoamyl nitrate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate,
n-hexyl nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl
nitrate, 2-ethylhexyl nitrate, sec-octyl nitrate, n-nonyl nitrate,
n-decyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate,
methylcyclohexyl nitrate and isopropylcyclohexyl nitrate and also
branched decyl nitrates of the formula
R.sup.1R.sup.2CH--CH.sub.2--O--NO.sub.2 in which R.sup.1 is an
n-propyl or isopropyl radical and R.sup.2 is a linear or branched
alkyl radical having 5 carbon atoms, as described in WO
2008/092809. Additionally suitable are, for example, nitrate esters
of alkoxy-substituted aliphatic alcohols such as 2-ethoxyethyl
nitrate, 2-(2-ethoxyethoxy)ethyl nitrate, 1-methoxypropyl nitrate
or 4-ethoxybutyl nitrate. Additionally suitable are also diol
nitrates such as 1,6-hexamethylene dinitrate. Among the cetane
number improver classes mentioned, preference is given to primary
amyl nitrates, primary hexyl nitrates, octyl nitrates and mixtures
thereof.
[0028] In one preferred embodiment, 2-ethylhexyl nitrate is present
in the fuel oils as the sole cetane number improver or in a mixture
with other cetane number improvers.
[0029] Said mixtures of the monocarboxylic acids or the
dimerization or trimerization products thereof (A) and the
polycyclic hydrocarbon compounds (B) can in principle be used to
increase the cetane numbers in any fuel oils which comprise cetane
number improvers and additives with detergent action. However, they
are especially suitable for use in middle distillate fuels,
especially in diesel fuels. However, use in heating oil or kerosene
is also possible. Diesel fuels or middle distillate fuels are
typically mineral oil raffinates which generally have a boiling
range from 100 to 400.degree. C. These are usually distillates
having a 95% point up to 360.degree. C. or even higher. However,
these may also be what is called "ultra low sulfur diesel" or "city
diesel", characterized by a 95% point of, for example, not more
than 345.degree. C. and a sulfur content of not more than 0.005% by
weight, or by a 95% point of, for example, 285.degree. C. and a
sulfur content of not more than 0.001% by weight. In addition to
the diesel fuels obtainable by refining, the main constituents of
which are relatively long-chain paraffins, those obtainable by coal
gasification or gas liquefaction ["gas to liquid" (GTL) fuels] are
suitable. Also suitable are mixtures of the aforementioned diesel
fuels with renewable fuels (biofuel oils) such as biodiesel or
bioethanol. Of particular interest at present are diesel fuels with
low sulfur content, i.e. with a sulfur content of less than 0.05%
by weight, preferably of less than 0.02% by weight, particularly of
less than 0.005% by weight and especially of less than 0.001% by
weight of sulfur. Diesel fuels may also comprise water, for example
in an amount of up to 20% by weight, for example in the form of
diesel-water microemulsions or in the form of what is called "white
diesel".
[0030] In a preferred embodiment, said mixtures of the
monocarboxylic acids or the dimerization or trimerization products
thereof (A) and the polycyclic hydrocarbon compounds (B) are used
together with cetane number improvers and additives with detergent
action in fuel oils which consist [0031] (a) to an extent of 0.1 to
100% by weight, preferably to an extent of 0.1 to less than 100% by
weight, especially to an extent of 10 to 95% by weight and in
particular to an extent of 30 to 90% by weight, of at least one
biofuel oil based on fatty acid esters, and [0032] (b) to an extent
of 0 to 99.9% by weight, preferably to an extent of more than 0 to
99.9% by weight, especially to an extent of 5 to 90% by weight, and
in particular to an extent of 10 to 70% by weight, of middle
distillates of fossil origin and/or of vegetable and/or animal
origin, which are essentially hydrocarbon mixtures and are free of
fatty acid esters.
[0033] Said mixtures of components (A) and (B) can of course also
be used together with cetane number improvers and additives with
detergent action in fuel oils which consist to an extent of 100% by
weight of at least one biofuel oil (a), based on fatty acid
esters.
[0034] The fuel oil component (a) is usually also referred to as
"biodiesel". This preferably comprises essentially alkyl esters of
fatty acids which derive from vegetable and/or animal oils and/or
fats. Alkyl esters typically refer to lower alkyl esters,
especially C.sub.1- to C.sub.4-alkyl esters, which are obtainable
by transesterifying the glycerides which occur in vegetable and/or
animal oils and/or fats, especially triglycerides, by means of
lower alcohols, for example, ethanol, n-propanol, isopropanol,
n-butanol, isobutanol, sec-butanol, tert-butanol or especially
methanol ("FAME").
[0035] Examples of vegetable oils which can be converted to
corresponding alkyl esters and can thus serve as the basis of
biodiesel are castor oil, olive oil, peanut oil, palm kernel oil,
coconut oil, mustard oil, cottonseed oil, and especially sunflower
oil, palm oil, soybean oil and rapeseed oil. Further examples
include oils which can be obtained from wheat, jute, sesame and
shea tree nut; it is additionally also possible to use arachis oil,
jatropha oil and linseed oil. The extraction of these oils and the
conversion thereof to the alkyl esters are known from the prior art
or can be inferred therefrom.
[0036] It is also possible to convert already used vegetable oils,
for example used deep fat fryer oil, optionally after appropriate
cleaning, to alkyl esters, and thus for them to serve as the basis
of biodiesel.
[0037] Vegetable fats can in principle likewise be used as a source
for biodiesel, but play a minor role.
[0038] Examples of animal oils and fats which can be converted to
corresponding alkyl esters and can thus serve as the basis of
biodiesel are fish oil, bovine tallow, porcine tallow and similar
fats and oils obtained as wastes in the slaughter or utilization of
farm animals or wild animals.
[0039] The parent saturated or unsaturated fatty acids of said
vegetable and/or animal oils and/or fats, which usually have 12 to
22 carbon atoms and may bear an additional functional group such as
hydroxyl groups, and which occur in the alkyl esters, are
especially lauric acid, myristic acid, palmitic acid, stearic acid,
oleic acid, linoleic acid, linolenic acid, elaidic acid, erucic
acid and/or ricinoleic acid.
[0040] Typical lower alkyl esters based on vegetable and/or animal
oils and/or fats, which find use as biodiesel or biodiesel
components, are, for example, sunflower methyl ester, palm oil
methyl ester ("PME"), soybean oil methyl ester ("SME") and
especially rapeseed oil methyl ester ("RME").
[0041] However, it is also possible to use the monoglycerides,
diglycerides and especially triglycerides themselves, for example
castor oil, or mixtures of such glycerides, as biodiesel or
components for biodiesel.
[0042] In the context of the present invention, the fuel oil
component (b) shall be understood to mean the abovementioned middle
distillate fuels, especially diesel fuels, especially those which
boil in the range from 120 to 450.degree. C.
[0043] In a further preferred embodiment, said mixtures of the
monocarboxylic acids or the dimerization or trimerization products
thereof (A) and the polycyclic hydrocarbon compounds (B) are used
together with cetane number improvers and additives with detergent
action in fuel oils which have at least one of the following
properties: [0044] (.alpha.) a sulfur content of less than 50 mg/kg
(corresponding to 0.005% by weight), especially less than 10 mg/kg
(corresponding to 0.001% by weight); [0045] (.beta.) a maximum
content of 8% by weight of polycyclic aromatic hydrocarbons; [0046]
(.gamma.) a 95% distillation point (vol/vol) at not more than
360.degree. C.
[0047] Polycyclic aromatic hydrocarbons in (13) shall be understood
to mean polyaromatic hydrocarbons according to standard EN 12916.
They are determined according to this standard.
[0048] The fuel oils comprise said mixtures of the monocarboxylic
acids or the dimerization or trimerization products thereof (A) and
the polycyclic hydrocarbon compounds (B) in the context of the
present invention generally in an amount of 1 to 1000 ppm by
weight, preferably of 5 to 500 ppm by weight, especially of 10 to
300 ppm by weight, in particular of 25 to 150 ppm by weight, for
example of 40 to 100 ppm by weight.
[0049] The cetane number improver or a mixture of a plurality of
cetane number improvers is present in the fuel oils normally in an
amount of 10 to 10 000 ppm by weight, especially 20 to 5000 ppm by
weight, even more preferably of 50 to 2500 ppm by weight and
especially of 100 to 1000 ppm by weight, for example of 150 to 500
ppm by weight.
[0050] The additive with detergent action or a mixture of a
plurality of such additives with detergent action is present in the
fuel oils, typically in an amount of 10 to 2000 ppm by weight,
especially 20 to 1000 ppm by weight, even more preferably of 50 to
500 ppm by weight and especially of 30 to 250 ppm by weight, for
example of 50 to 150 ppm by weight.
[0051] Said fuel oils such as diesel fuels or middle distillate
fuels, or such as said mixtures of biofuel oils and middle
distillates of fossil, vegetable or animal origin, may comprise, in
addition to the mixtures of the monocarboxylic acids or the
dimerization or trimerization products thereof (A) and the
polycyclic hydrocarbon compounds (B), the additives with detergent
action and the cetane number improvers, as coadditives, further
customary additive components, especially cold flow improvers,
corrosion inhibitors, demulsifiers, dehazers, antifoams,
antioxidants and stabilizers, metal deactivators, antistats,
lubricity improvers, dyes (markers) and/or diluents and
solvents.
[0052] Cold flow improvers suitable as further coadditives are, for
example, copolymers of ethylene with at least one further
unsaturated monomer, in particular ethylene-vinyl acetate
copolymers.
[0053] Corrosion inhibitors suitable as further coadditives are,
for example, succinic esters, in particular with polyols, fatty
acid derivatives, for example oleic esters, oligomerized fatty
acids and substituted ethanolamines.
[0054] Demulsifiers suitable as further coadditives are, for
example, the alkali metal and alkaline earth metal salts of
alkyl-substituted phenol- and naphthalenesulfonates and the alkali
metal and alkaline earth metal salts of fatty acid, and also
alcohol alkoxylates, e.g. alcohol ethoxylates, phenol alkoxylates,
e.g. tert-butylphenol ethoxylates or tert-pentylphenol ethoxylates,
fatty acid, alkylphenols, condensation products of ethylene oxide
and propylene oxide, e.g. ethylene oxide-propylene oxide block
copolymers, polyethyleneimines and polysiloxanes.
[0055] Dehazers suitable as further coadditives are, for example,
alkoxylated phenol-formaldehyde condensates.
[0056] Antifoams suitable as further coadditives are, for example,
polyether-modified polysiloxanes.
[0057] Antioxidants suitable as further coadditives are, for
example, substituted phenols, e.g. 2,6-di-tert-butylphenol and
2,6-di-tert-butyl-3-methylphenol, and also phenylenediamines, e.g.
N,N'-di-sec-butyl-p-phenylenediamine.
[0058] Metal deactivators suitable as further coadditives are, for
example, salicylic acid derivatives, e.g.
N,N'-disalicylidene-1,2-propanediamine.
[0059] A lubricity improver suitable as a further coadditive is,
for example, glyceryl monooleate.
[0060] Suitable solvents, especially for diesel performance
packages, are, for example, nonpolar organic solvents, especially
aromatic and aliphatic hydrocarbons, for example toluene, xylenes,
"white spirit" and the technical solvent mixtures of the
designations Shellsol.RTM. (manufacturer: Royal Dutch/Shell Group),
Exxol.RTM. (manufacturer: ExxonMobil) and Solvent Naphtha. Also
useful here, especially in a blend with the nonpolar organic
solvents mentioned, are polar organic solvents, in particular
alcohols such as 2-ethylhexanol, decanol and isotridecanol.
[0061] When the coadditives and/or solvents mentioned are used
additionally, they are used in the amounts customary therefor.
[0062] The examples which follow are intended to illustrate the
present invention without restricting it.
EXAMPLES
[0063] In a diesel fuel which is typical for the European market,
conforms to standard EN 590 and comprised a proportion of 7% by
weight of biodiesel (FAME), the cetane numbers were determined to
EN ISO 5165 with the following additions:
TABLE-US-00001 Sample Cetane number to No. Dosage [ppm by weight]
EN ISO 5165 1 none (base fuel) 51.9 2 65 PIBSI * 52.1 0
2-ethylhexyl nitrate 60 tall oil fatty acid 110 Solvent Naphtha
heavy Tot. 5 customary antifoam + customary dehazer 3 65 PIBSI *
52.9 360 2-ethylhexyl nitrate 0 tall oil fatty acid 110 Solvent
Naphtha heavy Tot. 5 customary antifoam + customary dehazer 4 65
PIBSI * 53.6 360 2-ethylhexyl nitrate 60 tall oil fatty acid 110
Solvent Naphtha heavy Tot. 5 customary antifoam + customary dehazer
* commercial polyisobutenyl-substituted succinimide (Kerocom .RTM.
PIBSI from BASF SE)
[0064] As evident from the above results, the addition of tall oil
fatty acid to a fuel which comprises an additive with detergent
action but no cetane number improver does not lead to any
significant change in the cetane number (sample No. 2). The
addition of cetane number improver to a fuel which comprises an
additive with detergent action but no tall oil fatty acid leads to
an increase in the cetane number of 1.0 compared to the unadditized
base fuel (sample No. 3). When, in contrast, both tall oil fatty
acid and cetane number improver are added to the fuel which
comprises an additive with detergent action, there is a
surprisingly large increase in the cetane number by 1.7 units
compared to the unadditized base fuel to 53.6 (sample No. 4).
[0065] This demonstrates the synergistic action of the mixture of
components (A) and (B), represented by tall oil fatty acid, and
cetane number improvers from the increase in the cetane number.
* * * * *