DESCRIPTION

Technical field

The invention regards an additive for fuels, a method for the production thereof and fuels that comprise such additive for fuels. The additive for fuels has application in the reduction of particulate emission and of fuel consumption in internal combustion engines.

State of the art

Particulate matter, suspended particulate, atmospheric particulate, fine particles, total suspended particulate are terms which commonly identify the set of substances suspended in the air. Particulate matter is the pollutant substance considered today to have the greatest impact in urban areas; it is composed by all those solid and liquid particles dispersed in the atmosphere with a diameter that ranges from a few nanometers up to 500 micrometers and beyond. Numerous elements contribute to forming these air-suspended aggregates, and comprise both natural and human factors, such as the emissions of combustion of the internal combustion engines. A formal identification of the size is used, Particulate Matter, abbreviated PM, followed by the maximum aerodynamic diameter of the particles. For example, one speaks of PM ₀ for all the particles, with diameter less than 10 μιη; PM ₀ is an inhalable dust, i.e. capable of penetrating into the upper respiratory section. Various studies have ascertained that PM ₀ has a negative effect on health and that, in cities, road transportation - especially in the case of old vehicles - is the main cause of high PM ₀ values.

In order to reduce the particulate matter values, it has been sought to improve combustion in order to lower the emission of particulate and to reduce fuel consumption.

There have been various attempts to obtain this improvement. One has been described by Teruo Higa in the European patent application EP 0 631 998 A1 in which it is proposed to place the fuel in contact with ceramics provided with mixtures of microorganisms. The effectiveness of this system is however quite controversial.

The document JP 2000/186287 A describes an additive for fuels which comprises microorganisms and nutrients therefor. Christine C. Gaylarde et al. ("Microbial Contamination of Stored Hydrocarbon Fuels and its Control" in: Rev. Microbiol, vol. 30, no. 1 , Sao Paolo 1999, pp. 1 -10) instead speaks of undesired contamination of fuels with microorganisms.

Another avenue is that of adding water to the diesel oil. The diesel oil/water emulsions are fuels constituted by diesel, water and a chemical additive which has the function of stabilizing the emulsion. The use of stabilized emulsions in diesel engines allows obtaining substantial reductions of the emissions of black fumes, particulate (PM ₀ ) and nitrogen oxides (NO _x ). One problem of the diesel oil/water emulsions is the unsatisfactory stability of the same. In addition, they often lead to problems of corrosion, and there are difficulties in transferring the water/fuel principle onto gasoline.

Presentation of the invention

Object of the present invention is to propose an additive for fuels, both diesel and gasoline, which overcomes the aforesaid drawbacks, which is simple and inexpensive to produce.

Another object of the present invention is to propose an additive for fuels that reduces harmful emissions, in particular the particulate matter, of the internal combustion engines and which contributes to lowering fuel consumption.

Further object of the invention is to propose an additive for fuels that assists in keeping the engine and relative filters clean.

Further object of the invention is to supply a relative method for producing one such additive and a relative fuel.

Another object of the invention is to supply an additive for fuels which, in addition to being adapted to reduce harmful emissions, is also biodegradable and non-toxic.

The abovementioned objects and others that will be better illustrated hereinbelow are attained by an additive for fuels as defined in the first claim. Surprisingly and contrary to the experiences with the system proposed by Teruo Higa in the document EP 0 631 998 A1 , the additive according to the invention has numerous advantages: there is a substantial reduction of the PM-io particulate emissions, which can reach 90% with respect to the use of the fuel without additive; a 5% to 15% increase of the coverable distance that can be obtained with a liter of fuel as a function of the type and age of the car; an increase of the drive torque with a consequent reduction of engine maintenance. With the addition of the additive according to the invention into engines equipped with anti-particulate filters, the engine regeneration frequency is reduced or the regeneration interval is even eliminated.

The use of the additive according to the invention prevents the formation of residues in the combustion chamber and algae and/or mucilage in the tank. The additive is hence also an optimal engine detergent.

A further advantage of the additive according to the invention is its 100% biodegradability and its non-toxicity. This is a natural, non-toxic, non-irritating composition, which is burned without leaving damaging residues.

The aforesaid advantages ensure that with the use of the additive in the fuels, a significant energy savings is obtained along with a reduction of the environmental impact; this is true for the single consumer and in general with regard to overall public and private.

The action of the additive as detergent for fuels according to the invention keeps the mechanical parts of the engine cleaned and hence simplifies the maintenance of the engine itself.

The sugars present in the additive constitute the necessary nutriment for the microorganisms for their activation and growth. The microorganisms used are common microorganisms, known to those skilled in the art. Microorganisms purchasable at Leibniz-lnstitut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH can for example be used. Particular types of strains are not necessary; for example, the strains described in the patent application EP 0 631 998 A1 are also suitable.

Suitable combinations of microorganisms are also found in the abovementioned European document.

Advantageously, the liquid base of the additive that also serves as solvent for the sugars and other ingredients is only constituted by water.

The water used is preferably a mineral water, i.e. a water containing mineral salts. A mineral water is adapted to form a suitable environment for the microorganisms and their activation.

Preferably, said water is mineral water and preferably comprises from 20% to 40%, more preferably 30% by volume of water from natural sources of the Dolomites, with a composition as indicated in the experimental part of this description, or water that replicates the mineral composition of this water from the Dolomites.

The mixture of Bacillus subtilis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus bulgahcus, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus plantarum, Lactococcus diacetylactis (also known as Enterococcus diacetylactis), Lactococcus lactis, Rhodopseudomonas palustris, Saccharomyces cerevisiae, Streptococcus thermophilus, i.e. the specific combination of the effective microorganisms, assists in maintaining them for a longer time, since they live in symbiosis with each other.

In a particularly preferred variant, the additive for fuels also comprises Lactobacillus rhamnosus.

Advantageously, the additive for fuels according to the invention also comprises an essential oil, preferably selected from among sage essential oil, pinus sylvestris essential oil and mint essential oil or mixtures thereof, preferably in quantities that correspond to 0.026 - 0.120 ml for every liter of additive, and/or a dye, preferably blueberry juice, in particular 0.08 - 0.19 ml of blueberry juice in a liter of additive.

Surprisingly, these essential oils and dyes do not alter the aforesaid advantages of the additive but confer a pleasant bouquet to them as well as a distinctive color. These are biodegradable, not toxic ingredients. All types of sage, mint or pinus sylvestris are suitable for extracting the relative essential oils.

Another aspect of the invention regards a fuel that comprises (a) microorganisms selected from among lactic bacteria, yeasts, actinomycetes, photosynthetic bacteria, fermenting fungi and preferably mixtures thereof; and (b) sugars selected from among sucrose of sugar beet, i.e. common white sugar, sucrose of sugarcane, i.e. common cane sugar, sugar beet molasses, sugarcane molasses, and mixtures thereof, wherein said fuel does not comprise any solid carrier and wherein the fuel comprises the microorganisms as defined in the first claim.

The fuel thus comprises the additive according to the invention, and the aforesaid advantages are attainable with its use in internal combustion engines.

Preferably, the fuel according to the invention comprises mixtures of microorganisms as defined above. Advantageously, the fuel also comprises an essential oil, preferably selected from among sage essential oil, pinus sylvestris essential oil and essential mint oil or mixtures thereof, and/or a dye, preferably blueberry juice. A further aspect of the invention regards a method for producing an additive for fuels comprising the following steps:

(a) preparation of water;

(b) addition of sugars and microorganisms as defined in any one of the claims from 1 to 2;

(c) activation of the mixture obtained in step b) with heating, preferably at 20-40°C, preferably at 27°C, for 10-25 days, preferably for 15 days;

(d) optionally, addition of an essential oil, preferably selected from among sage essential oil, pinus sylvestris oil and mint oil or mixtures thereof, and/or of a dye, preferably blueberry juice.

In a preferred variant of the method according to the invention, in step (b) the quantities of the microorganisms and the sugars are selected in a manner such that

(i) the concentration of said sugars corresponds to 2.5 - 1 1 kg of said sugars, preferably 2 - 5 kg of sugar of sugar beet and 2 - 6 kg of sugar molasses of sugarcane, more preferably 3 kg of sugar of sugar beet and 5 kg of sugar molasses of sugarcane for 1000 liters of said water; and that

(ii) every 1000 liters of said water comprises from 15 to 30 liters, preferably 20 liters, of a first concentrate of said microorganisms as defined in claim

1 , wherein the concentration of the lactobacilli is > 3 x 10 ⁶ UFC/ml and wherein the concentration of the yeasts is < 1 x 10 ⁶ UFC/ml, wherein optionally 15% - 25%, preferably 20%, by volume of said first concentrate is substituted by a second concentrate comprising Lactobacillus casei, Lactobacillus plantarum and Lactobacillus rhamnosus with a concentration of the lactobacilli which lies in the interval that varies from 2 - 5 x 10 ⁸ UFC/ml; and that

(iii) in the case of step (d), the concentration of said essential oils corresponds to 50 - 150 ml of said essential oils and to 150 - 250 ml of a blueberry juice for every 1000 liters of said water; and

(iv) the mixture obtained after the step (c) or (d) is diluted with water in a manner such that the quantity of added water corresponds to 30% - 90%, preferably about 50%, of the volume of the additive subjected to dilution.

The water used for the dilution is advantageously water, as defined above. The addition of the essential oils can also occur after the dilution, by always maintaining the quantity of 50 - 1 50 ml of essential oil in 1 300 - 1 900 liters of finished additive.

Another aspect of the invention refers to a method for preparing a fuel comprising the following step: addition of 7 - 20 ml, preferably 1 0 - 1 5 ml, of an additive obtained according to the method defined in claim 7 to 1 00 liters of fuel.

Unexpectedly, these small concentrations of microorganisms and sugars are, in addition to preventing obstructions of parts of the engine (e.g. of the injectors), also adapted to obtain the aforesaid advantages; for example, considerably reductions of emissions are obtained, in particular of particulate matter, along with a substantial reduction of the fuel consumption values. Also the detergent effect is already observed at these concentrations. In order to obtain comparable effects with water/diesel/emulsifying systems known at the state of the art, great quantities of emulsifying agents are necessary which are often damaging for the environment.

The last aspect of the invention regards the use of the fuel according to the invention and of the fuel obtained according to the method for producing fuel according to the invention in order to drive an internal combustion engine.

The characteristics of the water, of the sugars, of the microorganisms and of the other ingredients defined for the additive and the fuel according to the invention are - mutatis mutandis - also applicable to the methods and to the use according to the invention.

The particular combination of the components of the additive for fuels according to the invention ensures a uniform distribution of the microorganisms within the liquid without the risk of blocking the injectors of the engines. Even if the preferred doses of microorganisms (and sugars) respectively within the additive or the fuel having the additive are very low, they already have considerable effect.

The additive according to the invention also increases the cetane number within the diesel oil with such additive. The cetane number is an indicator of the behavior of the fuel during ignition. Its value is calculated by detecting the delay between the injection and the ignition, assigning a value equal to 1 00 to the cetane (Ci ₆ H ₃₄ ), and a value equal to 0 to the methylnaphthene. The index therefore expresses the "readiness" of the fuel to be ignited, where the greater the cetane number, the greater such readiness. Sometimes, together with this value, also the so-called cetane index is reported which is calculated by accounting for the density and volatility of the fuel, which in first approximation approaches the cetane number. The diesel oil normally has values of the cetane number around 50-52: an increase of the cetane number allows lowering the particulate matter and emissions of carbon monoxide (CO) and hydrocarbons (HC). With the additive and the fuel according to the invention, values of the cetane of 57 were attained - and this without the addition of considerable quantities of water (known method for increasing the cetane number) which always involves corrosion problems.

The additive according to the invention can be used in any type of automotive fuel, e.g. diesel oil, gasoline or gas, and hence it is not limited to diesel oil like the diesel oil/water emulsions described in the state of the art.

It is advisable to use the additive with every car fill-up, even if satisfactory effects, in particular detergent effects, are already obtained with a less frequent use, for example with every third car fill-up.

Variants of the invention are the subject of the dependent claims.

The description of preferred embodiments of the additive for fuels, of the relative fuel, of the methods for the production thereof and of the use thereof according to the invention is given as an exemplifying and non-limiting example.

Description of the embodiments

Hereinbelow, the production is described of 1500 liters of additive for fuels in the preferred embodiment.

Approximately 972 liters of water from the source are prepared (or a mixture of 972 liters of water which contain 30% by volume of water from natural sources of the Italian Dolomites, as defined below, and the rest of the water from any one natural source).

The preferred water from natural sources of the Dolomites has the following composition:

Ca 430 mg/l (± 43); Mg 69.5 mg/l (± 7.0); SiO ₂ 7.2 mg/l (± 0.5), Na 5865 μ$/\ (± 586), K 1242 μ9/Ι (± 124), Ag 4.5 μ9/Ι (± 4), Al < 20 μς/Ι, Sb < 0.5 μς/Ι, As < 0.5 μ9/Ι, Ba 12 μς/Ι (± 1 ), B < 10 μς/Ι, Be < 10 μς/Ι, Cd < 0.5 μς/Ι, Co < 3 μς/Ι, total Cr < 3 μς/Ι, Fe 129 μς/Ι (± 13), Li 1 1 μς/Ι (± 3), Mn 8.0 μς/Ι (± 0.8), Hg < 3 μQ/\, Mo < 1 μς/Ι, Ni < 0.5 μς/Ι, Pb 9.2 μQ/\ (± 3.0), Cu < 3.0 μς/Ι, Rb 67 μQ/\ (± 7), Se < 3 μQ/\, Sn < 0.5 μQ/\ Sr 6726 μQ/\ (± 670), Tl < 3 μQ/\, Ti < 3 μς/Ι, V < 5 μς/Ι, Zn 10 μς/Ι (± 1 ).

The values are determined with the method EPA 6010 C 2000; only for silica was the method IRSA 100/41 10:1994 applied.

The measurement uncertainty associated with the results has a coverage factor k=2, to which a probability corresponds equal to 95% that the actual result falls within such uncertainty range.

20 liters of a concentrate of microorganisms are added. For example, a concentrate is used with a mixture of actual microorganisms (according to the theory of Teruo Higa) that comprises per milliliter > 3 x 10 ⁶ UFC lactobacilli and < 1 x 10 ⁶ UFC yeast. Alternatively, 20% by volume of the aforesaid concentrate is substituted with a concentrate of lactobacilli which comprises at least 2 - 5 x 10 ⁸ UFC/ml of lactic bacteria.

As concentrate of lactobacilli, auxiliary means are for example suitable for the ensilage of fodder, such as the KomBioflor-s ^® product. This contains the following lactobacilli: Lactobacillus casei, Lactobacillus plantarum and Lactobacillus rhamnosus in a 3% sugarcane molasses, and comprises acids with natural fermentation. The dry residue is indicated with 22 g/kg, the unrefined fats with 0.1 g/kg, the unrefined protein with 1 .5 g/kg, the unrefined ashes with 4.5 g/kg, the unrefined fibers with 0.15 g/kg, extraction substances lacking nitrogen with 15 g/kg, and the sugars with 6 g/kg; the sum of the fermentation acids corresponds to 5 g/kg, the pH is 3.5-3.7.

Concentrates containing actual suitable microorganisms are for example EMbio PLUS or EMbio Original, used in organic agriculture, which comprise a mixture of the following microorganisms: Bacillus subtilis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus plantarum, Lactococcus diacetylactis (also known as Enterococcus diacetylactis), Lactococcus lactis, Rhodopseudomonas palustris, Saccharomyces cerevisiae, Streptococcus thermophilus.

The producer of EMbio PLUS indicates the following parameters for the product thereof: pH 3.60 ± 0.20; sugar content (measurement with the refraction index ) 4.5 ± 2.0°Bx, the redox potential = 180mV ± 30; the moisture (AOAC method) 94% ± 4.0; lactic bacteria (FDA BAM method) > 3.0 x 10 ⁶ UFC/ml; yeasts < 1 .0 x 10 ⁶ UFC/ml, presence of PSNB (purple non-sulfur bacteria) determined with phase contrast; total coliforms (method FDA BAM) < 10 UFC/ml; molds (method FDA BAM) < 10 UFC/ml; total heavy metals (As, Cd, Fe, Pb, Hg, Ni) (determined with ICP) < 10 ppm (Fe < 25 ppm, As < 1 ppm).

The Bacillus subtilis can be of the natto variant. R. sphoeroides and Enterococcus thermophilus can also be contained in the product.

Subsequently, 3 kg of common white sugar and 5 kg of common molasses are added.

The mixture thus obtained is activated by means of constant heating at about 27°C for 10 days.

In order to confer a pleasant bouquet to the additive, 50 to 150 ml of different types of essential oils can be added, such as mint essential oil, pinus sylvestris essential oil or sage essential oil (50 - 150 ml). A color can be given to the additive by adding 150 to 250 ml of a blueberry extract (giant blueberry juice, pasteurized, without addition of water or sugars). The addition of other plant extracts does not alter the result in the fuel. The mixture is diluted in order to obtain 1500 liters of liquid, and the dilution can occur with normal mineral water or with mineral water containing water from natural sources of the Dolomites. With the additive thus obtained (without the addition of essential oils or blueberry juice), tests were conducted on various engines.

Various measurements were carried out of the opacity of the fumes, as is normally done in competent garages. The opacimeter is an instrument for measuring the opacity of the fumes, generally used in the automotive field for determining the level of pollution of the engine. The opacity is conventionally measured as a percentage of the light attenuation, but such value is a function of the optical path of the light beam. In order to be unconstrained by the optical path, the measurement unit k is used.

in which L _a = actual length of the optical path, τ = transmittance, N = opacity percentage. The measurement unit is in m ^"1 if L _a is expressed in meters. For every specific diesel engine, there is a specific k value.

The following tables 1 to 8 summarize the results of the measurement of the value k conducted in order to analyze the fumes produced by different engines, using diesel oil added with an additive according to the invention. In every test, 10 ml of additive was added to every 50 liters of fuel.

All the tested engines first traveled at least 1000 km with fuel having the additive.

The reaction time (the time which is given to the additive for entering into a full operating cycle) was always 15-20 minutes.

The first car tested was a FORD TRANSIT TOURNEO, TURBO DIESEL of 2005 with a turbo-compressor diesel engine of ABFA type. The environmental measurement conditions were the following: temperature 26°C, atmospheric pressure 97.2 kPa and relative humidity 47%; while the parameters of the engine were the following: temperature of the engine oil 86°C, rev/min min. 798 and max. 4070. The measurements were conducted with a TECNOMOTOR model G381 opacimeter and with a revolution counter TECNOMOTOR model PF M941 .

Table 1

The second car tested was a FORD TRANSIT CONNECT, TURBO DIESEL of 2004 (European pollutant emissions standard Euro 4, 5). The environmental measurement conditions were the following: temperature 28°C, atmospheric pressure 100.6 kPa and relative humidity 29%; while the parameters of the engine were the following: slow measurement (low revolutions): oil temperature of the engine 81 °C, rev/min min. 852 and max. 4134, fast measurement (high revolutions): T(oil) = 82°C, rev/min 799 and 4037. The measurements were conducted with an opacimeter Motorscan S.p.A. model Multex 7000 and with a revolution counter BRAIN BEE model MGT-300. Table 2

The measurement was repeated with diesel oil without additive. The conditions were the following: slow measurement (low revolutions): temperature 31 °C, pressure 100.8 kPa, relative humidity 47%; oil temperature of the engine = 81 °C, rev/min min. 799 and max. 3998; fast measurement (high revolutions): temperature 31 °C, pressure 100.8 kPa, relative humidity 48%, oil temperature of the engine 91 °C, rev/min min. 81 1 and max. 4060. Table 3

The third car tested was a VOLKSWAGEN TIGUAN, TURBO DIESEL of 2013. The engine was a turbo compressor with a maximum revolutions limit in operating conditions of 4500. The environmental measurement conditions were the following: temperature 26°C, atmospheric pressure 91 .1 kPa and relative humidity 48%; while the parameters of the engine were the following: oil temperature of the engine 89.0°C, rev/min min. 670 and max. 2630. The value k was measured with an opacimeter TECNOMOTOR model 840 and with a revolution counter TECNOMOTOR model PF M941 . Table 4

The fourth car tested was a LAND ROVER DISCOVERY with aspirated engine 15 P (engine displacement: 2495 cm ³ ) with diesel turbo compressed diesel supply, tare 2255 kg of 2002 (directive 72/306/CE). The environmental measurement conditions were the following: temperature 12°C, atmospheric pressure 100.4 kPa and relative humidity 13%; while the parameters of the engine were the following: oil temperature of the engine 83.0°C, rev/min min. 900 and max. 4000. The value k was measured with an opacimeter Motorscan S.p.A. model Multex 7000 and with a revolution counter Motorscan S.p.A. model SMOKE RPM 9000.

Table 5

The same car was tested two years later. The environmental measurement conditions were the following: temperature 22°C, atmospheric pressure 100.0 kPa and relative humidity 43%; while the parameters of the engine were the following: oil temperature of the engine 82.0°C, rev/min min. 856 and max. 4157. The value k was measured with an opacimeter Motorscan S.p.A. model Multex 7000 and with a revolution counter BRAIN BEE model GPRPM-300. Table 6

A further measurement conducted a year later resulted in an average value of k of 0.4.

A further test was conducted with a FORD TRANSIT TOURNEO, TURBO DIESEL of 2005 with an ABFA engine, engine displacement 1998 cm ³ with turbo compressed diesel supply, tare 1783 kg.

The environmental measurement conditions were the following: temperature 23°C, atmospheric pressure 100.0 kPa and relative humidity 67%; while the parameters of the engine were the following: oil temperature of the engine 84.4°C, rev/min min. 780 and max. 3720. The opacimeter used was a TECNOTEST model 495/01 and a revolution counter TECNOTEST model CGOP. Table 7

The last car tested was a CITROEN BERLINGO with turbo-compressor diesel engine type 9HX (engine displacement: 2495 cm ³ ) with diesel oil, tare 1330 kg of 2005 with km 152745. The environmental measurement conditions were the following: temperature 5°C, atmospheric pressure 97.1 kPa and relative humidity 77%; while the parameters of the engine were the following: oil temperature of the engine 80.0°C, rev/min min. 750 and max. 4030 for the measurement after the catalytic muffler; oil temperature of the engine 92.0°C, rev/min min. 740 and max. 41 10 for the measurement before the catalytic muffler. The value k was measured with an opacimeter TECNOMOTOR model G381 and with a revolution counter TECNOMOTOR model PF M941 .

Table 8

With the additive and the fuel according to the invention, it is possible to obtain values of k that are clearly below the limit values indicated by the producers of the respective engines.

Table 9 reports the results of an analysis of exhaust gases of a gasoline engine, with the use of the additive according to the invention. 10 ml of additive were used every 50 liters of fuel with a reaction time of 15/20 minutes. The environmental conditions were the following: temperature 29°C, pressure 97.0 kPa, relative humidity 41 %. The measurement was executed with a Corghi model G430-C gas analyzer and with a revolution counter TECNOMOTOR model PF M941 . Table 9

At 870 rev/min, the measured value for CO2 was 16.2 vol%, at 2510 rev/min the measured value of CO2 was 16.10 vol%; the hydrocarbons HC corresponded to 14 ppm vol, and O2 to 0.06 vol%.

Table 10 summarizes the respective reference values for gasoline engines EURO 1 , 2, 3 and 4:

Table 10

Also in the case of use of the additive according to the invention in gasoline, considerable lowering of the CO emissions was obtained.

As is clear from the abovementioned results, the k values and the CO (carbon monoxide) level obtainable with fuel having additive are clearly below the threshold provided by law.

The active anti-particulate filter (in French "filtre a particules", FAP) is a device employed by the PSA Peugeot Citroen group for lowering the polluting emissions from fine dust of diesel engines. The agglomerates captured by the filter obviously tend to obstruct it. Periodically, the filter is thus "cleaned" by burning the captured agglomerates. The automatic system of FAP decides the opportune moment for the regeneration of the filter, mainly during extra-urban travel every 300-400 kilometers, by evaluating the pressure drop that the engine must overcome astride the filter - which tends to increase with the obstruction of the device itself. Long-duration tests of the fuel having the additive according to the invention, in development mules with diesel engines, have instead indicated that even with about 3000 km traveled no blowing of the FAP filter is necessary; without the use of the additive, it would be necessary to clean this filter practically every day.

Tests conducted with a FORD 2000 with a load up to 13 quintals (on average 4 quintals), and up to 9 people on board at an average speed of 90 km/h on mountain roads, demonstrated a fuel consumption savings that varies at least from 5% to 15%. Even lower consumptions were observed: with 1 liter, in some cases, it was possible to travel 10-14 km, while without the additive 5 to 7 km could be traveled.

Reported hereinbelow is the analysis of an automotive diesel oil which contains the additive according to the invention:

Test Method Measurement Measured Maximum unit value limit volume mass at 15°C UNI EN ISO kg/m ³ 832,950 820,845

12185:1999

flash point UNI EN ISO °C 70 > 55

2719:2005

water content UNI EN ISO mg/kg 170 < 200

12937:2001

total contamination UNI EN mg/kg 5.2 < 24

12662: 2008

cetane index UNI EN ISO 57 > 46

4264:2007

distillation:

% (w/w) recovered at UNI EN ISO % w/w 41 < 65 250°C 3405:201 1

% (w/w) recovered at UNI EN ISO % w/w 92 > 85 350°C 3405:201 1

95% (w/w) UNI EN ISO °C 357.3 < 360 recovered 3405:201 1 content of fatty acid UNI EN % w/w 5.7 < 7 methyl esters (FAME) 14078:2010

content of sulfur UNI EN ISO mg/kg 5.5 < 10

20846:2012

The reported values for the diesel oil added with the additive according to the invention all lie within the values prescribed by law.

Another analysis of the exhaust gases was conducted with a TECNOMOTOR model GA570 gas analyzer, a TECNOMOTOR model RPM-GAS revolution counter, a CORGHI model MS1200S speed meter on a Volkswagen TIGUAN, which confirm the low carbon monoxide emission levels obtainable with the additive according to the invention: CO - 0.0 %vol; CO ₂ = 4.3 %vol; HC 16 ppm vol; O ₂ 15.07 %vol.

The invention has attained the object of proposing an additive for fuels and a relative fuel which overcome the abovementioned drawbacks, which are simple and inexpensive to produce.

The present invention proposes an additive for fuels that reduces harmful emissions, in particular the particulate matter, of the internal combustion engines, which contributes to the lowering of the fuel consumption and which also helps to keep the engine and the relative filters clean. In addition, the invention provides an additive for fuels that is biodegradable and non-toxic and simultaneously ensures low values of k and high cetane values in diesel engines, and low emissions of CO in gasoline engines.

Furthermore, the invention provides relative methods for producing one such additive and one such fuel, and a use of the fuel.

During execution, further non-described modifications or variants can be made to the additive according to the invention, to the fuel, to the methods for the production thereof and to the use of the fuel, subject of the invention.

If such modifications or such variants should fall within the scope of the following claims, they must all be deemed protected by the present patent.