AU2015205854B2 - Diesel fuel composition, comprising components based on biological raw material, obtained by hydrogenating and decomposition fatty acids - Google Patents

Abstract

Abstract Biodiesel fuel composition for diesel engines wherein the fuel composition consists of: a) 0.1-99 % by volume of a hydrocarbon component free of aromatics or a mixture of hydrocarbon components free of aromatics, produced from biological raw material by hydrogenating fatty acids and/or fatty acid esters to give a hydrocarbon, which is isomerized; b) 0-20 % by volume of components containing oxygen, selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water, and mixtures containing the same; both components a) and b) being mixed as an emulsion or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process wherein the remainder of the fuel composition by volume comprises said diesel components based on crude oil and/or fractions from Fischer-Tropsch process, wherein said biodiesel fuel composition has a density less than rapeseed oil methyl ester based fuel, and leaves no impurity residues. 21/07/15,22453abstract.doex,2

Description

-1 - 2015205854 21 Jul2015

DIESEL FUEL COMPOSITION, COMPRISING COMPONENTS BASED ON BIOLOGICAL RAW MATERIAL, OBTAINED BY HYDROGENATING AND DECOMPOSING FATTY ACIDS

TECHNICAL FIELD

[0001] This application is a divisional of Australian Application No. 2010200726 and Australian Patent No. 2003258753, the disclosures of which are deemed to be incorporated herein.

[0002] The present invention relates to a fuel composition for diesel engines, comprising components based on animal fat, diesel components based on crude oil and/or fractions from Fischer-Tropsch process, and optionally components containing oxygen.

PRIOR ART

[0003] Currently used fuels for diesel engines mainly contain components from crude oil. The aim of the climate agreement of Kyoto is to eliminate detrimental influences due to human activities on the atmosphere, and thus on the climate. The EU has agreed on reducing emissions of carbon dioxide, methane and other greenhouse gases by eight per cent until 2010, starting from the levels of 1990. One of the objects of the EU agricultural policy is to find uses for agricultural overproduction, and to increase the self-sufficiency for fuels. Accordingly, an EU directive is being prepared, demanding that at least two per cent of the petrol and diesel fuel consumed in 2005 should be of biological origin. It is anticipated that one of the requirements of this directive is to increase the proportion of biocomponents to about six per cent until 2010. The directive will be validated in all EU countries in the near future.

[0004] At the moment, the most common component of biological origin in fuels is rapeseed oil methyl ester, referred to as RME. RME is either used as such or as a mixture with fuels. Drawbacks of RME are its poor miscibility with diesel fuels, and, 21/07/15,ck22453speciclaims.docx, 1 -2- 2015205854 21 Μ 2015 in comparison to a conventional diesel fuel (EN 590), particularly under low temperature conditions, its poor storage stability and poor performance at low temperatures. Moreover, it causes engine fouling and increases emissions of nitrogen oxides (NOx). A by-product of the production process of RME is glycerol, which may become a problem when high amounts of the product are produced. Esters of other vegetable oils may be produced in similar manner, and methyl esters of fatty acids are generally known as FAMEs (fatty acid methyl ester). These FAMEs may be used in similar applications as the rapeseed oil methyl ester, but they also have a negative effect on the quality of the diesel fuel, particularly with respect to the performance thereof at low temperatures, and in addition, the use thereof in fuels increases the emissions of nitrogen oxides. In some cases FAME and RME cause higher particle emissions and smoke development of the cold driven engine.

[0005] Vegetable oils and animal fats may be processed to decompose the ester and/or fatty acid structure and to saturate the double bonds of the hydrocarbon chains, thus obtaining about 80 to 85 % of n-paraffin product relative to the mass of the starting material. This product may be directly mixed with a diesel fuel, but a problem with the fuel so produced is its poor performance at low temperatures. In addition, n-paraffms having a carbon number of fatty acids are waxy with a high solidification point, typically above +10 °C, thus limiting the use of these compounds in diesel fuels at least at low temperatures.

[0006] WO 2001049812 discloses a method for producing a diesel fuel with a molar ratio of iso-paraffins to η-paraffms of at least 21:1. In the method, a feedstock containing at least 50 % of Cio-paraffins is contacted with a catalyst in the isomerisation reaction zone.

[0007] WO 2001012581 discloses a method for producing methyl esters useful as biological diesel fuel, wherein mixtures of fatty acids and triglycerides are esterified in one phase. In this method, a solution is formed from fatty acids, triglycerides, alcohol, acid catalyst and co-solvents at a temperature below the boiling point of the solution. A co-solvent is used in amounts to provide a single phase then the solution 21/07/15,ck22453speciclaims.docx,2 -3 - 2015205854 21 Jul 2015 is maintained for a period of time sufficient for the acid catalyzed esterification of the fatty acids to take place. Thereafter, the acid catalyst is neutralised, a base catalyst is added to transesterify the triglycerides, and finally, the esters are separated from the solution. Thus a biofuel containing esters is obtained, having a glycerol content of less than 0.4 % by weight.

[0008] US 6,174,501 presents a method for producing oxidized diesel fuel of biological origin. This oxidized biological diesel fuel comprises a mixture of transesterified triglycerides.

[0009] FI 100248 describes a two-step process for producing middle distillate from vegetable oil by hydrogenating fatty acids of the vegetable oil, or triglycerides, to give n-paraffins, and then by isomerising the n-paraffins to give branched-chain paraffins. A published foreign counterpart of this patent is patent application SE 9700149, which has matured into patent SE 520633.

[0010] Any gases, liquid droplets and solid particles present in the atmosphere in amounts being hazardous to human health and/or having a detrimental effect on animals, plants and different materials, are considered as air pollutants. Air pollution mainly originates from three main emission sources, i.e. the industry, energy production, and traffic.

[0011] The harmfulness of particle emissions is caused by the substances and compounds they carry, such as heavy metals and other carcinogenic and mutagenic compounds. Particles present in exhaust gases are small and thus hazardous to health.

[0012] Greenhouse gases allow for the penetration of the radiation from the sun to reach the earth, preventing, however, the thermal radiation from escaping from the earth back to space. They thus contribute to the warming of the earth. One of the most significant greenhouse gases is carbon dioxide released, for instance, during the combustion of fossil fuels. 21/07/15,ck22453speciclaims.docx,3 -4- 2015205854 21 Μ 2015 [0013] Nitrogen oxides are acidifying compounds. This acidification may, for instance, lead to plant damages and species changes in surface waters. Nitrogen oxides may also react with oxygen to give ozone. This phenomenon contributes particularly to air quality in cities.

[0014] As the above teachings indicate, there is a need for a high quality fuel composition for diesel engines containing components of biological origin and also meeting the quality requirements for diesel fuels under low temperature operation conditions. Moreover, the fuel should be more environmentally friendly than prior art solutions.

[0015] It would be advantageous to a more environmentally friendly fuel composition for diesel engines containing components of biological origin, and also meeting the quality requirements for diesel fuels under low temperature conditions.

GENERAL DESCRIPTION OF THE INVENTION

[0016] The fuel composition for diesel engines of the invention, containing components of biological origin, comprises at least one component produced from a biological starting material obtained from animals, diesel components based on crude oil and/or fractions from Fischer-Tropsch process, and optionally components containing oxygen.

[0017] The characteristic features of the fuel composition for diesel engines containing components of biological origin are presented in the appended claims.

[0018] In an embodiment of the invention there is provided a fuel composition for diesel engines, wherein the fuel composition comprises: a) 0.1-99% by volume of a component or a mixture of components produced from biological raw material originating from animals by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons and isomerising the hydrocarbons to give isoparaffins; b) 0-20% by volume of components containing oxygen selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water and mixtures 21/07/15,ck22453speciclaims.docx,4 -5 - 2015205854 21 Μ 2015 containing the same; both components a) and b) being mixed as an emulsion with or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process.

DETAILED DESCRIPTION OF THE INVENTION

[0019] It was surprisingly found that the diesel fuel composition of the invention, containing components of biological origin, also meets the quality requirements for diesel fuels under low temperature conditions. The composition of the diesel fuel of the invention comprises: a) 0.1-99% by volume of a component or a mixture of components produced from biological raw material originating from animals, or both animals and plants, or originating from animals, plants and/or fish, by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons and isomerising the hydrocarbons to give iso-paraffins; b) 0-20% by volume of components containing oxygen selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water and mixtures containing the same; both components a) and b) being mixed as an emulsion with or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process. Said components a) and b) are mixed in diesel components based on crude oil and/or in fractions from Fischer-Tropsch process by forming an emulsion with or by dissolving said components in diesel components based on crude oil and/or fractions from Fischer-Tropsch process.

[0020] Preferably the composition of the invention comprises: a) 5-80% by volume of a component or a mixture of components produced from biological raw material originating from animals, or both animals and plants, by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons and isomerising the hydrocarbons to give iso-paraffins; b) 0-20% by volume of components containing oxygen selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water and mixtures containing the same; both components a) and b) being mixed as an emulsion with or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process. 21/07/15,ck22453speciclaims.docx,5 -6- 2015205854 21 Μ 2015 [0021] More preferably the composition of the invention comprises: a) 10-80% by volume of a component or a mixture of components produced from biological raw material originating from animals, or both animals and plants, by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons and isomerising the hydrocarbons to give iso-paraffins; b) 0-20% by volume of components containing oxygen selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water and mixtures containing the same; both components a) and b) being mixed as an emulsion with or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process.

[0022] Most preferably the composition of the invention comprises: a) 10-80% by volume of a component or a mixture of components produced from biological raw material originating from animals, or both animals and plants, by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons and isomerising the hydrocarbons to give iso-paraffins; b) 1-20% by volume of components containing oxygen selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water and mixtures containing the same; both components a) and b) being mixed as an emulsion with or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process.

[0023] It was generally thought that products based on animal origin, as well as products based on recycled fats, could not be used in diesel fuels. These products were expected to contain high amounts of sulphur-, nitrogen- and metal-containing impurities, which would weaken the quality of the composition and make their processing very difficult. This, however, turns out not to be true.

[0024] The biological based fuel compositions of the current invention have remarkably lower “green house emissions” than the corresponding crude oil based products. The animal- and fish-based fuel compositions of the current invention also have significantly improved performance ability under cold conditions. These compositions may have a turbidity point of lower than 0°C, preferably lower than -10°C and more preferably lower than -20°C. These compositions may have a 21/07/15,ck22453speciclaims.docx,6 -7- 2015205854 21 Jul2015 turbidity point of even -30°C or lower while simultaneously having a cetane number of 60 or higher. This differs markedly from the turbidity points presented in SE 9700149, which are considerably higher.

[0025] The biological raw material originating from animals, containing fatty acids and/or fatty acid esters, is processed to yield the biological component of the present application. Said biological component is obtained by hydrogenating and decomposing fatty acids and/or fatty acid esters to give hydrocarbons having carbon number of 6-24, typically n-paraffins as the product having a carbon number of 12-24, and isomerising the hydrocarbons, typically n-paraffins thus obtained to give isoparaffins. Typically, after the isomerisation, the iso-paraffin content is more than 20 wt-%, preferably more than 30 wt-% and more preferably more than 50 wt-%. In one embodiment of the invention the iso-paraffin content may be more than 60 wt-% or even more than 70 wt-% in said biological component.

[0026] Examples of suitable biological raw materials are animal-based fats such as lard, tallow, train oil, and fats contained in milk, as well as recycled animal fats of the food industry and mixtures of the above.

[0027] The fuel composition can optionally further comprise a component or mixture of components produced from biological raw material originating from plants. The biological raw material originating from plants can be selected from various vegetable oils, and mixtures thereof containing fatty acids and/or fatty acid esters. Examples of suitable materials are wood-based and other plant-based fats and oils such as rapeseed oil, colza oil, canola oil, tall oil, sunflower oil, soybean oil, hempseed oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, as well as fats contained in plants bred by means of gene manipulation, and recycled plant sourced fats of the food industry.

[0028] The basic component of a typical vegetable or animal fat is triglyceride i.e. a triester of glycerol and three fatty acid molecules having the structure presented in the following formula I: 21/07/15,ck22453speciclaims.docx,7 -8- 2015205854 21 Μ 2015 Ο Ο •0 'σ 1-α.ν >r‘ (I) where Ri, R2, and R3 are hydrocarbon chains, and Ri, R2, and R3 may be saturated or unsaturated Ce - C24 alkyl groups. The fatty acid composition may vary considerably in biological raw materials of different origin.

[0029] n-paraffins, iso-paraffins or mixtures thereof produced from the biological raw material may be used as a diesel fuel component in accordance with the properties desired for the diesel fuel. Fractions from Fischer-Tropsch-process typically contain high levels of n-paraffins and, optionally, they may be isomerised either simultaneously during the processing of the component of biological origin or separately therefrom, or they may be used as such.

[0030] The biological component may be produced, for instance, with a process comprising at least two steps and optionally utilizing the counter-current operation principle. Before the first step the feedstock may optionally be prehydrogenated to saturate double bonds of the hydrocarbon chain, at a temperature of 100-400°C, preferably at 150-250°C. In the first hydrodeoxygenation step of the process, carried out at a temperature of 200-400°C, preferably at 250-350°C, optionally running counter-current, the structure of the biological raw material is broken, compounds containing oxygen, nitrogen, phosphor and sulphur as well as light hydrocarbons as gas are removed, and thereafter, olefinic bonds are hydrogenated. In the second, isomerisation step of the process, optionally running counter-current, isomerisation is carried out to give branched hydrocarbon chains, thus improving the low temperature properties of the paraffins. 21/07/15,ck22453speciclaims.docx,8 -9- 2015205854 21 Jul2015 [0031] Biological raw material selected from plant oils and fats, animal fats, and mixtures thereof, containing fatty acids and/or fatty acid esters, is used as the feedstock.

[0032] High quality hydrocarbon component of biological origin, particularly useful as a component of a diesel fuel, as an iso-paraffinic solvent and as a lamp oil, is obtained as the product having a high cetane number that may even be higher than 70. A component with a turbidity point lower than -30 °C and a cetane number higher than 60 can also be achieved. Further, said hydrocarbon component of biological origin is free of aromatics. The content of naphthenes in said hydrocarbon component may be less than 30 wt-%, preferably less than 10 wt-%, more preferably less than 5 wt-% or even less than 1 wt-%. Both aromatics and naphthenes present in the hydrocarbon product decrease the cetane number and increase cold smoke during start up of the engine. The process can be adjusted according to the desired cetane number and turbidity point.

[0033] Advantages of the diesel fuel composition of the present invention include superior performance at low temperatures and an excellent cetane number compared to solutions of prior art using FAME-based components like RME. Problems associated with the performance at low temperatures may be avoided by isomerising waxy n-paraffms having a carbon number comparable with that of fatty acids to give iso-paraffins. The properties of the products thus obtained are excellent, especially with respect to diesel applications, the n-paraffins typically have cetane numbers higher than 70, and iso-paraffins higher than 60, and thus they have an improving effect on the cetane number of the diesel pool, which clearly makes them more valuable as diesel components. Moreover, the turbidity point of the isomerised product may be adjusted to the desired level, for example below -30 °C, whereas the corresponding value is about 0 °C for RME and more than +15 °C for n-paraffins. Table 1 below compares the properties of an isomerised biological component, RME, and a commercial diesel fuel. 21/07/15,ck22453speciclaims.docx,9 2015205854 09 Aug 2017 - 10-

Table 1

Product Density (kg/m3) Cetane number Turbidity point (°C) Isomerized biological component obtained from tallow <800 >_60 <-30 RME -880 ~ 50 ~0 Diesel fuel EN 590 820-845 >51 0 to -15

Tallow is a generic term used for fats obtained from cow, sheep (mutton or lamb) or reindeer. The tallow used in this table was obtained from Atria Finland Ltd, a Finnish meat producing company.

[0034] Fouling of engines is considerably diminished and the noise level is clearly lower when using isomerised biological component fuel composition in comparison with similar prior art fuels of biological origin containing FAME components, and further, the density of the composition is lower. The composition does not require any modifications of the automobile technology or logistics. Higher energy content per unit volume may be mentioned as a further advantage compared to RME.

[0035] The properties of the diesel fuel composition of biological origin according to the invention correspond to those of a high quality diesel fuel based on crude oil. A composition free of aromatics can be obtained and, in contrast to FAME, it leaves no impurity residues.

[0036] Nitrogen oxide emissions due to the fuel composition of the invention are lower that those from a similar FAME-based product, and further, the particle emissions are clearly lower, and the carbon portion of the particles is smaller. These significant improvements in the emissions of the fuel composition of biological origin are environmentally very important.

[0037] Table 2 below, compares the cold properties of the animal fat based product of the current invention with those exemplified by the product disclosed in Example 4 from SE 9700149. 2015205854 21 Μ 2015 - 11 -

Table 2 Feed Vegetable fat Animal fat Property Method Unit Example 4 from SE9700149 Hydrotreated and Isomerised Density 15°C ENISO 12185 kg/nri 770 776 Turbidity Point ASTM D5771 °C -12 -35 CFPP EN 116 Ann °c -11 -34 Sulphur content ASTM D5453 mg/kg 0 <1 Cetane Number IQT NM 353 >74 78 [0038] This Table presents the surprisingly improved results obtained for the instant invention under cold conditions. That is, the animal fat-based fuel composition of the instant invention has excellent cold properties when compared with those compositions presented in SE 9700149. Specifically, the lower turbidity point of the animal fat-based fuel composition of the instant invention affords less fuel filter plugging during cold weather operations.

[0039] Also, the cold filter plugging point (CFPP) indicates that the animal fat-based fuel composition of the instant invention provides trouble-free flow in fuel systems at ambient temperatures about 20°C lower as compared to the cited prior art. Most surprisingly these improved performance qualities are obtained without a decrease in the fuel ignition delay characteristics as evidenced by the instant invention’s high cetane number, which is comparable to that of the prior art. It was generally thought that one cannot improve cold flow properties to these low levels without decreasing the fuel ignition delay.

[0040] The invention will now be illustrated by means of the following examples without intending to limit the scope thereof. 21/07/15,ck22453speciclaims.docx,l 1 2015205854 09 Aug 2017 - 12-

EXAMPLES

Example 1

Manufacture of animal fat based component [0041] The hydrogenation of animal fat was carried out in a fixed bed tube reactor. The animal fat was Atria tallow as used earlier in table 1. The hydrogenation reaction was carried out in the presence of NiMo catalyst under a pressure of 50 bars, with WHSV of 1 - 2 1/h and at a reaction temperature from 250 to 300°C. Hydrogen to oil ratio was 500 - 1500 normal liters H2 per liter oil fed. Hie hydrogenated product oil contained no oxygen compounds.

[0042] Isomerisation of the above-obtained hydrogenated animal fat was carried out in a fixed bed tube reactor in the presence of Pt-SAPO-catalyst under a pressure of 40 bars, with WHSV of 1.5 1/h and at a reaction temperature of 328°C. Hydrogen to oil ratio was 300 normal liters PL per liter oil fed.

[0043] Low temperature properties of the obtained animal fat based component are presented in the Table 3 below.

Table 3

Feed Animal fat Property Method Hydrogenated and Isomerised Density / 15°C/ kg/nf* ENISO 12185 776 Turbidity point /°C ASTMD5771 -35 CFPP /°C EN 116 Ann -34 Sulphur / mg/kg ASTM D5453 <1 Cetane Number / IQT NM 353 78 21O7/l5,ck22453spcciclaims.docx,12 - 13 - 2015205854 21 Jul2015

Example 2 [0044] Composition containing 20 wt-% of animal fat based component and 80 wt-% crude oil based diesel component [0045] The hydrogenated and isomerised animal fat component (biocomponent) produced in example 1 was blended to crude oil based diesel component (European diesel fuel EN590) in amounts of biocomponent 20 wt-% and EN590 80 wt-%. Table 4 below shows the characteristics of the obtained product and the components.

Table 4

Component/Product Animal fat Crude oil Blend Property Method Hydrogenated and isomerised Diesel fuel component 20 wt-% diesel from animal fat and 80 wt-% crude oil diesel Density / 15°C / kg/m3 ENISO 12185 776 829 818 Turbidity point / °C ASTM D5771 -35 -29 -31 CFPP / °C EN 116 Ann -34 -43 -44 Sulphur / mg/kg ASTM D5453 < 1 <5 <5 Cetane Number / IQT NM 353 78 51 (engine) 58 21/07/15,ck22453speciclaims.docx,13 - 14- 2015205854 21 Μ 2015

Example 3 [0046] Composition containing 20 wt-% of animal fat based component and 80 wt-% crude oil based diesel component blended with 5 wt-% of oxygen containing component [0047] The hydrogenated and isomerised animal fat component (biocomponent) produced in example 1 was blended to crude oil based diesel component (European diesel fuel EN590) in amounts of biocomponent 20 wt-% and EN590 80 wt-%. To this blend 5 wt % of oxygen containing component (RME= rapeseed oil fatty acid ester) was blended. The characteristics of the blend and of the obtained product are provided in the Table 5 below:

Table 5

Component/Product Property Method Blend Blend + RME 20 wt-% diesel from animal fat and 80 wt-% crude oil diesel Blend + 5 wt % RME Density / 15°C / kg/mJ ENISO 12185 818 821 Turbidity point / °C ASTM D5771 -31 -30 CFPP/°C EN 116 Ann -44 -43 Sulphur / mg/kg ASTM D5453 <5 5 Cetane Number / IQT NM 353 58 58 21/07/15, ck22453speciclaims.docx, 14 - 15 - 2015205854 21 Jul2015

Comparative Example 4 [0048] The following Table 6 compares the emission characteristics of a conventional diesel fuel used in Europe in summer, EN 590 (DI), to those of a composition containing 60 % by volume of hydrogenated and isomerised tall oil (TOFA), and 40 % by volume of the European summer diesel fuel EN 590.

Table 6

Characteristic Unit 60 % b.v. TOFA + 40 % b.v. DI DI Turbidity point °C -15 -8 Cetane number - 61.2 55.9 Aromatics % b.w. 8.7 19.2 Total aromatics (IP391) % b.v. 9.1 20.0 Polyaromatics (IP391) % b.v. 0.8 1.6 n-paraffins % b.w. 14.7 24.5 i-paraffins % b.w. 34.2 26.1 Naphtenes % b.w. 42.4 30.2 b.w. = by weight b.v. = by volume

Comparative Example 5 [0049] Table 7 below compares the emission characteristics of a high quality reformed crude oil based diesel fuel available on the Finnish market (DITC, produced by Fortum Oyj), to those of compositions containing 30 % by volume of hydrogenated and isomerised tall oil (TOFA), and 70 % by volume of DITC, or containing 30 % by volume of tall oil methyl ester (MME), and 70 % by volume of DITC. 21/07/15,ck22453speciclaims.docx,15 - 16-

Table 7

Characteristic Unit DITC 30 % b.v. TOFA + 70 % b.v. DITC 30 % b.v. MME + 70 % b.v. DITC Cetane number - 51 57 48 NOx emissions (compared to DITC) % -1 to -4 +3 Particles % -3 +22 - carbon % -10 to -30 0 to -10 -PAH % ±0 ±0 Combustion noise - decreases ±0 b.v. = by volume 2015205854 21 Μ 2015 [0050] Although the fuel composition of Examples 4 and 5 do not directly demonstrate the present invention as the compositions do not contain isomerised animal based biological material, the compositions can be blended with the biocomponent of Example 1 to provide a useful fuel composition.

[0051] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0052] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of the common general knowledge. 21/07/15, ck22453speciclaims.docx, 16 2015205854 09 Aug 2017 - 17-

The Atria (allow used in the examples and listed in Tables 1 and 3 was obtained from Atria Finland Ltd. The tallow was solid at room temperature and was purified before hydrogenation and isomerisation. It was purified by washing with an alkali solution and by diatomaceous earth filtration. The Atria tallow was analysed and has the following characteristics:-

Table 8: Atria Tallow : Fatty acid distribution

Chain length: double bonds % C14:0 2.32 C14:l 0.36 05:0 0.17 06:0 25.47 06:1 2.29 06:2 0.10 06:3 1.68 07:0 0.48 07:1 0 08:0 23.55 08:1 34.88 08:2 4.68 08:3 0.59 09:0 0.28 09:1 0.14 C20:0 0.27 C20:l 0.57 C20:2 0.17 C20:3 0 C22:0 0.04 unknown 1.90 TOTAL 100.0 2015205854 09 Aug 2017 - 18-

Table 9: Atria Tallow : Carbon number distribution Chain Length % C14 2.68 C15 0.17 C16 27.86 C17 2.16 C18 63.69 C19 0.43 C20 1.01 C22 0.08 C23 0.01 C24 0 C25 0 C26 0 unknown 1.90 TOTAL 100.00

Table 10: Atria Tallow : Properties ProperLv Atria Tallow Density 15 °C 911.9 kg/nr* Density 50 °C 888.9 kg/nr Sulphur 5.4 ppm Nitrogen 3 ppm Br-number 24 g/lOOg Iodine number 47 Free fatty acids (TAN) 1.00 mg KOH/g sapo.numbcr Water 0.05% 2015205854 09 Aug 2017 - 19-

Table 11: Atria Tallow : GPC Analysis GPC Analysis Atria Tallow Oligomers 0 Triglycerides 99.4% Diglycerides 0 Monoglycerides 0 Carboxylic acids 0.6%

Table 12: Atria Tallow : Elemental Analysis Metals (ICP) Atria Tallow Aluminium <2 Barium <1 Calcium <1 Chromium <1 Copper <1 Iron <1 Magnesium <1 Manganese <1 Sodium <2 Nickel <1 Phosphorous <1 Lead <1 Silicon <1 Vanadium <1 Zinc <1

Claims (5)

1. The claims defining the invention are as follows:

   1. A biodiesel fuel composition for diesel engines wherein the fuel composition comprises: a) 0.1-99 % by volume of a hydrocarbon component free of aromatics or a mixture of hydrocarbon components free of aromatics, produced from biological raw material, wherein the biological raw material originates from animal fats and/or fish, by hydrogenating fatty acids and/or fatty acid esters to give a hydrocarbon, which is isomerized; b) 0-20 % by volume of components containing oxygen, selected from the group consisting of aliphatic alcohols, ethers, fatty acid esters, water, and mixtures containing the same; both components a) and b) being mixed as an emulsion or dissolved in diesel components based on crude oil and/or fractions from Fischer-Tropsch process wherein the remainder of the fuel composition by volume comprises said diesel components based on cmde oil and/or fractions from Fischer-Tropsch process, wherein said biodiesel fuel composition has a density less than rapeseed oil methyl ester based fuel.
2. 2. The biodiesel fuel composition according to claim 1, wherein said biological raw material originates from animal fats.
3. 3. The biodiesel fuel composition according to claim 1 or 2, wherein said isomerized hydrocarbon has a turbidity point lower than -30°C and a cetane number higher than 60.
4. 4. The biodiesel fuel composition according to any one of the preceding claims wherein the density of the biodiesel fuel composition is less than the density of crude oil based conventional diesel fuel.
5. 5. The biodiesel fuel composition according to any one of the preceding claims wherein the biological raw material is a mixture originating from animal fats and/or fish and vegetable oil.