COMBUSTIBLE

FUEL

Abrégé français

La présente invention concerne un combustible comportant un additif pour augmenter le pouvoir calorifique, l'additif durcissant et ainsi, la manipulation du combustible étant améliorée.

Abrégé anglais

The invention relates to a fuel with an additive for increasing the net calorific value, wherein the additive hardens and the handling of the fuel is improved thereby.

Revendications

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Claims
1. A fuel comprising a starting material with a first additive,
characterised in that the additive comprises 50 to 60% palmitic acid, 40
to 50% stearic acid, maximum 1% lauric acid, maximum 3% myristic
acid and traces of oleic acid.
2. The fuel according to claim 1, characterised in that the fuel
comprises paraffin as a second additive.
3. The fuel according to claim 2, characterised in that the
maximum fraction of the second additive is as large as the fraction of
the first additive.
4. The fuel according to any one of the preceding claims, char-
acterised in that the starting material is pressed into shaped pieces.
5. The fuel according to any one of the preceding claims, char-
acterised in that the starting material is coal, biomass or a mixture
thereof.
6. A method for producing a fuel comprising the following
steps:
a) producing a starting material,
b) adding an additive according to claim 1 and/or an additive
according to claim 2, wherein
the fuel is pressed into a particular shape before or after adding
the additive.

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7. The method according to claim 6, wherein the additive is
heated to at least its specific melting point.

Description

CA 02674821 2009-07-08
PCT/EP2008/050407
(W02008/087144)
FUEL
The invention relates to a fuel and a method for producing this
fuel.
Fossil fuels in solid form and fuels from biomass have been known
for a long time. These fuels are needed in many branches of industry for
various applications but are mainly used for generating electrical energy
or heat in power plants or for heating purpose in private areas.
Due to the increasing shortage and the rising costs for fuels, at-
tempts are being made to increase the calorific value of the fuels by
means of additives.
It is known from US 4443227 to treat charcoal with a fatty-acid-
based additive and WO 96/14372 discloses a fuel made of organic ma-
terials which also has a fatty-acid-based additive.
A disadvantage of the additives used is that they do not harden
and the fuel is always greasy after addition of the additive and loses the
additive again. As a result, this can have the consequence during long
storage that the fuel completely loses the additive and all the advan-
tages of the additive are lost.
In addition, the fuel must be transported and stored in special
packagings since conventional packagings soften and tear due to the
additive or absorb the additive, which would result in an undesirable re-
duction of the additive in the fuel and in an increased fire risk.
With regard to the undesirable absorption of water, the fatty-acid-
based additive in the prior art behaves in a hydrophobic manner and
consequently minimises the incorporation of water, but cannot com-
pletely prevent this as a result of its continuously diminishing content in
the fuel.
A further disadvantage of the fuel in the prior art is that the addi-
tive cannot prevent abrasion during transport and storage since the ad-

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ditive does not harden and does not impart any additional stability to
the fuel.
When handling this fuel, the user must always wear gloves and
take other protective measures to avoid contamination of hands and
clothing by the greasy additive.
These disadvantages are unsatisfactory both for the manufacturer
and for the purchaser and in addition increase the costs of this fuel.
It is therefore an object of the invention to provide a fuel having
an additive which increases the calorific value of the fuel, which com-
pletely prevents incorporation of water, which exhibits no abrasion and
which can easily be handled.
This object is achieved with a fuel having the features of claim 1
and a method for producing such a fuel according to claim 6.
The basic idea of the invention is to treat a fuel with an additive
which enhances the calorific value and hardens.
The fuel according to the invention and a preferred composition of
the additive are described hereinafter. Coal can be selected as a fossil
starting material for the fuel, wherein all types of coal, e.g. black coal,
brown coal or charcoal are available for this purpose.
Any type of biomass is also suitable as starting material as an al-
ternative to a fossil starting material. Non-conclusive examples for this
are wood, wood chippings, grain such as wheat, rice, maize, rye, barley,
oats or millet, starch, for example, from beans, peas or potatoes, straw,
all types of seeds such as olive seeds, palm oil seeds, sunflower seeds,
pumpkin seeds and all cellulose-containing substances.
The fuel is preferably pressed into shaped pieces, wherein these
shaped pieces can have any possible shape. So-called briquettes or pel-
lets have proved to be particularly suitable shapes.
Before the pressing process, the starting material can be present
in any form, i.e. in powder form, as chips etc.

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It is understood that mixtures of black coal, brown coal, charcoal
and the biomasses are also suitable.
In the process, the starting material or the mixture thereof is
pressed into the desired shape at high pressure.
The additive according to the invention which is added to the
starting material comprises palmitic acid, stearic acid, lauric acid, myris-
tic acid and oleic acid and comprises the following fractions:
50 to 60% palmitic acid
40 to 50% stearic acid
maximum 3% myristic acid
maximum 1% lauric acid
and traces of oleic acid.
The percentages can comprise both weight percentages and vol-
ume percentages.
In this composition, the additive is present in a solid non-greasy
form whilst it has the same calorific-value-enhancing property as in the
prior art. For this reason, the incorporation of water can no longer form
in the fuel treated with this additive and the surface of the fuel is pro-
tected against abrasion or crack formation which reduces the breaking
of the fuel during transport. Consequently, there are no losses of start-
ing material or additive.
It is furthermore advantageous that the fuel need not be stored
and transported in any particular packaging since the fuel does not lose
the additive by greasing and does not release any type of dust and the
user of the fuel need not take any protective measures against con-
tamination of clothing and hands.
If, for example, barbeque charcoal is treated with the additive ac-
cording to the invention, this improves the lighting behaviour and also

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the handling of the barbeque charcoal since there is no risk of contami-
nation to the hands.
In addition, this encapsulation by the additive prevents any for-
mation of fine dust with the result that handling of the fuel is possible
without endangering the health of the user. If an increase in the calorific
value should only be of interest, the above composition of the additive
can be variably adjusted.
A method for producing this particular fuel is explained hereinaf-
ter.
During the production of the fuel, the additive can be processed
both in the solid and in liquid form. In solid form, the additive is
blended in flake form or powder form with the starting material which
can be present in any form. After producing a uniform mixture, this is
pressed into a specified shape at high pressure. During this pressing the
additive is distributed homogeneously inside the shaped pieces and
forms a protective layer on the surfaces thereof.
Alternatively, prior to application, the additive can be heated
above its specific melting point and used in liquid form. The specific
melting point of the afore-mentioned composition is around 62 degrees
Celsius.
In this case, the pressing process of the starting material can be
carried out both before and after treatment with the additive. The
treatment of the starting material can be carried out by passing through
or dipping into a bath containing the liquid additive or by spraying it on.
It should be mentioned that the treatment of the starting material with
liquid additive has the advantage that the incorporated water is expelled
due to the hot additive, with the result that the combustibility is further
improved. The preferred temperature of the additive when carrying out
the treatment is between 70 and 900 but can be higher or lower.

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An alternative to the aforesaid additive is paraffin. Paraffin is a
wax-like, combustible, odourless, non-toxic and hydrophobic substance
which, under certain conditions explained hereinafter has the relevant
properties for the invention.
Paraffin designates a mixture of alkanes, i.e. saturated hydrocar-
bons, wherein paraffin generally has the chemical molecular formula
CõHZn+Z where n can be between 18 and 50. Depending on the chain
length, the melting point varies between 30 and 80 C and the hardness
of the paraffin varies, with the advantageous possibility of selecting a
desired melting point and degree of hardness depending on the applica-
tion. Consequently, the method described above can be carried out un-
changed with paraffin.
Paraffin can be used alone or in combination with the additive ex-
plained above, it having been found that a mixture with the afore-
mentioned additive has very good properties with a maximum fraction
of 50% paraffin.
Furthermore, in cases in which merely an increase in the calorific
values is desired, vegetable and animal fats can be used alone or in any
mixing ratio. Non-conclusive examples for this are rapeseed oil, rape-
seed methyl ester, sunflower oil, linseed oil, olive oil, coconut oil or co-
conut fat, palm oil seeds, soya oil and all compositions of palmitic acid,
stearic acid, oleic acid, myristic acid and linoleic acid.