EP3830226A1

EP3830226A1 - Use of specific volatile fatty esters in petrol engines in order to reduce emissions

Info

Publication number: EP3830226A1
Application number: EP19755288.8A
Authority: EP
Inventors: Jean-Yves DUPRE; Jean-Louis REVEL
Original assignee: Biothink
Current assignee: Biothink
Priority date: 2018-07-27
Filing date: 2019-07-26
Publication date: 2021-06-09
Also published as: FR3084373B1; US20210163838A1; WO2020021070A1; BR112021001413A2; CN112639059A; CA3107558A1; FR3084373A1

Abstract

The invention relates to the use of esters of volatile fatty acids, such esters having a number of carbon atoms between 4 and 8, in a fuel for a petrol engine in order to reduce the emissions of nitrogen oxides, unburned hydrocarbons and particles of petrol engines.

Description

Use of special volatile fatty esters in petrol engines to reduce emissions

The present invention relates to improving the quality of gasoline in particular to reducing emissions of nitrogen oxides, unburned hydrocarbons and particles from gasoline engines.

Gasoline engines are now preferred over Diesel engines because they emit less harmful substances. They are intended to be used by a very large majority. However, they still emit nitrogen oxides, unburned hydrocarbons and particles which are dangerous for the environment and for human and animal health.

Currently, no satisfactory solution is proposed which makes it possible to reduce all of these emissions by petrol engines.

The objective of the invention is to find a product which can be used on an industrial scale, capable of reducing both the emissions of nitrogen oxides, unburned hydrocarbons and particles from petrol engines.

To respond to this the present invention proposes to use specific esters.

Esters have already been used in fossil fuels. In particular, the esters of vegetable oils or animal fats have been mixed with diesel. These esters are so-called “long” esters (16 to 20 carbon atoms per molecule) or “medium” esters (8 to 16 carbon atoms per molecule).

However, these esters do not meet the objective of the invention because they can not be used in admixture with petrol due to insufficient volatility. In addition, no ester has been used so far in admixture with gasoline to significantly reduce emissions.

However, according to the invention, surprisingly, the use of one or more volatile fatty acid esters "short" comprising per molecule a number of carbon atoms between 4 and 8, in l gasoline reduces emissions of nitrogen oxides, unburnt hydrocarbons and particulate matter from gasoline engines. In addition, advantageously, the use according to the invention simultaneously makes it possible to increase the octane number of the gasoline. Other characteristics and advantages will emerge from the description of the invention in details which follows.

Definitions

By "volatile fatty acid" within the meaning of the invention means a mono-carboxylic fatty acid with an aliphatic chain of one to six carbon atoms (formic, acetic, propionic, butyric, valeric and caproic acids), or l 'one of its isomers.

By "fuel" or "fuel for gasoline engine" within the meaning of the invention means a fuel capable of operating a gasoline engine, with or without particular adjustment of the engine, preferably an engine comprising at least gasoline and possibly other constituents.

By “short volatile fatty acid ester” or “short ester” or “short volatile fatty acid ester” within the meaning of the invention is meant an ester formed by the reaction of a volatile fatty acid on a alcohol so that the ester has a number of carbon atoms between 4 and 8.

By "unburned hydrocarbons" within the meaning of the invention means components comprising exclusively carbon and hydrogen atoms emitted by an engine. The unburnt hydrocarbons include methane CH ₄ and the other unburned hydrocarbons also called “non-methane hydrocarbons”.

By “gasoline octane number” within the meaning of the invention is generally meant either the Ron octane number or the Mon octane number.

By "research octane number" of gasoline or "Ron number" within the meaning of the invention means an index measured according to the method NF EN ISO 5164: 2005.

By "engine octane number" of gasoline or "Mon number" within the meaning of the invention means an index measured according to the method NF EN ISO 5163: 2005.

By “incorporation of a compound at the rate of x% by volume in the fuel” (in particular by “incorporation of esters at the rate of x% by volume in the fuel”) within the meaning of the invention is meant the constitution by any appropriate means of a mixture by adding a volume of x% of the compound (for example of esters) and a volume of lx% of gasoline and any other additives present in the fuel. The fuel is thus made up of x% of the compound on the one hand and lx% of gasoline and any other additives on the other. By "nitrogen oxides" within the meaning of the invention means compounds comprising only oxygen and nitrogen atoms, the most common in engine emissions being nitrogen monoxide NO and dioxide nitrogen N0 ₂ .

By "number of carbons" of an ester or an alkane is meant the number of carbon atoms of an ester or alkane molecule.

By “use of a compound at the rate of x% by volume of fuel” (in particular by “use of esters at the rate of x% by volume of fuel”) within the meaning of the invention means the use in a gasoline engine of a fuel consisting of the compound (for example one or more esters), petrol and any other additives, obtained by incorporating the compound at the rate of x% by volume in the fuel. Thus the fuel is made up of x% of the compound on the one hand and by l-x% of gasoline and any other additives on the other hand.

Detailed description of the invention

The invention therefore relates to the use of at least one volatile fatty acid ester, said ester comprising a number of carbons between 4 and 8, in a fuel for a gasoline engine to reduce both emissions of nitrogen oxide and unburnt hydrocarbons and preferably also to reduce particles from petrol engines.

Preferably the volatile fatty acid ester (s) comprising a number of carbons between 4 and 8 are used at the rate of at least 15% by volume of the fuel constituted by the ester (s), petrol and any other constituents, even more preferably at the rate of at least 20%, preferably at the rate of at least 30%, and according to an embodiment particularly suitable for the rate of at least 50%. These ratios allow particularly effective results to be obtained in terms of reducing emissions of nitrogen oxides, unburned hydrocarbons and particles from petrol engines.

The ester (s) of short volatile fatty acids which are useful according to the invention can be chosen from the following esters: ethyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, ethyl hexanoate, propyl acetate, propyl propionate, propyl butyrate, propyl valerate, butyl acetate, butyl propionate, butyl butyrate, and mixtures thereof.

The useful ester (s) according to the invention are preferably obtained in whole or in part from biomass (volatile fatty acids of biomass origin and / or alcohols of biomass origin) according to any suitable process. They can in particular be obtained in whole or in part and preferably entirely, by fermentation of biomass (anaerobic fermentation for volatile fatty acids and alcoholic or aceto-butanolic fermentation for alcohols) that is to say by esterification of volatile fatty acids of biomass origin with alcohols of biomass origin. Volatile fatty acids can also be obtained from dioxide or carbon monoxide in a microbial fuel cell. Thus, the volatile fatty acid esters comprising a number of carbons between 4 and 8 can be obtained in whole or in part by esterification of volatile fatty acids of biomass origin with alcohols of biomass origin or by esterification of acids volatile fats produced from dioxide or carbon monoxide in a microbial fuel cell by alcohols (alcohols can be of biomass origin or not).

Esters of volatile fatty acids comprising a number of carbon atoms between 4 and 8, in a fuel for a gasoline engine allow in particular and can be used so as to:

- reduce the emission of nitrogen oxides by petrol engines by at least 20% of the rate of incorporation of the ester in the fuel, for example a reduction of at least 10% for 50% of esters incorporated into the fuel (the emission of nitrogen oxides can in particular be measured according to a method that meets the requirements of the European Euro 6 regulation, ie regulation 459/2012 of May 29, 2012); and or

- reduce the emission of unburned hydrocarbons by petrol engines by at least 20% of the rate of incorporation of the ester in the fuel, for example a reduction of at least 10% for 50% of esters incorporated in fuel (the emission of unburned hydrocarbons may in particular be measured according to a method that meets the requirements of the European Euro 6 regulation, ie regulation 459/2012 of May 29, 2012);

- and possibly to reduce the emission of particles in mass and in number per kilometer traveled by petrol engines by at least 25% of the rate of incorporation of the ester in the fuel, for example a reduction of at least 12.5% for 50% of esters incorporated into the fuel (the emission of particles in mass and number per kilometer traveled by petrol engines can in particular be measured according to a method meeting the requirements of the European regulation Euro 6 i.e. regulation 459/2012 of May 29, 2012). Advantageously, the use according to the invention can also allow, in addition to the uses mentioned above:

- - to increase the “research” octane number of petrol by at least 2 points, preferably by at least 3 points; and or

- - to increase the “engine” octane number of the petrol by at least 2 points, preferably by at least 3 points.

These uses are very advantageous and allow to obtain a fuel which has a negative impact on the environment greatly reduced compared to the species currently used.

In combination with short esters, it is possible to use other gasoline additives, so as to increase the effects of volatile fatty acid esters and to act in synergy. It is in particular possible to add to gasoline, in addition to the short esters of volatile fatty acids, one or more alkanes whose number of carbon atoms in the molecule is between 4 and 10, to optimize combustion. These alkanes can be of petroleum origin or from biomass. Preferably, the alkanes used according to the invention come from a biomass. These alkanes, in combination with the short esters, make it possible to further reduce the emissions of nitrogen oxide and of unburned hydrocarbons. These alkanes are preferably chosen from octane, iso-octane, decane and their mixtures Indeed, these alkanes tend to improve the combustion of the mixture.

Preferably, these alkanes are used at an incorporation rate of between 0 and 50% by volume of fuel. Preferably, they are produced from volatile fatty acids resulting from an anaerobic fermentation of biomass by a so-called "Kolbe" electrolysis.

In addition to short esters, gasoline and possible alkanes, it is possible to add in combination one or more other product (s) in the fuel, said products being chosen from:

additives improving the octane number, such as for example organometallic compounds such as MMT and Ferrocene, or ethers such as ETBE or TAME or aromatic hydrocarbons such as toluene,

additives improving lubrication, such as for example medium esters such as hexyl valerate, hexyl caproate or longer esters, - products reducing combustion temperatures, such as, for example, nitrogen compounds such as amines, urea or ammonia, optionally mixed with water,

- alcohols such as isopropanol, butanol, hexanol or octanol,

- and their mixtures.

These additives make it possible in particular and in combination with the short volatile fatty acid esters to further reduce the emissions of nitrogen oxides and unburned hydrocarbons or else to improve other operating parameters of the engines with petrol.

The invention is now illustrated by examples and test results.

Examples

Example 1:

Use of 15% ethyl butyrate in Ron 95 petrol (85% petrol - 15% ethyl butyrate)

Example 2:

Use of 30% ethyl butyrate in Ron 95 petrol (70% petrol - 30% ethyl butyrate)

Example 3

Use of 30% ethyl butyrate and 10% iso-octane in Ron 95 petrol (60% petrol - 30% ethyl butyrate - 10% iso-octane)

Example 4:

Use of 50% ethyl butyrate and 20% iso-octane in Ron 95 petrol (30% petrol - 50% ethyl butyrate - 20% iso-octane)

Test results

The objective of the tests carried out is to evaluate the effect of the use of volatile fatty acid esters having a carbon number between 4 and 8, in a fuel comprising gasoline, on the emissions of nitrogen oxide, unburnt hydrocarbons and particles from petrol engines, and also on the octane number of petrol.

Emissions tests were carried out on a single-cylinder EP6 spark-ignition engine with the compositions of Examples 1 to 4 in comparison with Ron 95 gasoline alone.

The octane Ron measurements were carried out in the laboratory according to the regulatory standards of the French fuel specifications. The operating protocol for the tests is described below:

8 engine points per fuel mixture made to cover a representative use of a driving cycle:

- 1500 rpm, 4, 8, 12 bar and max of PMI

- 2000 rpm, 4, 8, 12 bar and max of PMI

For each engine point, the ignition advance is optimized to obtain that the PM I (average pressure indicated) is maximum. The richness of the mixture is regulated at 1. A wait of a few minutes is imposed in order to stabilize the engine thermal and the exhaust emissions. The analysis of the particles is carried out on a PBS PEGASOR probe.

The results relating to nitrogen oxide emissions are presented in Table 1.

[Table]

The results relating to the emissions of unburnt hydrocarbons are presented in Table 2.

[Table 2]

The results relating to particle emissions are presented in Table 3. [Table 3]

The results relating to the octane number are presented in Table 4.

[Table 4]

These results clearly show that the use of short esters of volatile fatty acids allows both:

- reduce nitrogen oxide emissions

- reduce emissions of unburned hydrocarbons

- reduce particle emissions.

It also significantly increases the octane number of gasoline.

Claims

claims

[Claim 1] Use in a gasoline engine fuel to reduce both nitrogen oxide and unburned hydrocarbon emissions from gasoline engines of at least one volatile fatty acid ester, a fatty acid volatile being a mono fatty acid with an aliphatic chain of one to six carbon atoms or one of its isomers, said ester comprising a number of carbons between 4 and 8.

[Claim 2] Use according to claim 1, also for reducing particulate emissions from gasoline engines.

[Claim 3] Use according to claim 1 or 2, characterized in that the ester or esters of volatile fatty acids comprising a number of carbons between 4 and 8, are used at a rate of at least 15% by volume of the fuel, the fuel being constituted by petrol, by the volatile fatty acid ester or esters containing a number of carbons between 4 and 8 and by any other constituents.

[Claim 4] Use according to the preceding claim, characterized in that the ester or esters of volatile fatty acids comprising a number of carbons between 4 and 8 are used at a rate of at least 30% by volume of the fuel.

[Claim 5] Use according to one of claims 3 or 4, characterized in that the ester or esters of volatile fatty acids comprising a number of carbons between 4 and 8 are used at a rate of at least 50% by fuel volume.

[Claim 6] Use according to one of the preceding claims, characterized in that the ester or esters of volatile fatty acids comprising a number of carbons between 4 and 8 are chosen from the following esters: ethyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, ethyl hexanoate, propyl acetate, propyl propionate, propyl butyrate, propyl valerate, butyl acetate, butyl propionate, butyl butyrate, and mixtures thereof.

[Claim 7] Use according to one of the preceding claims, characterized in that the ester or esters of volatile fatty acids comprising a number of carbons between 4 and 8 are obtained in whole or in part by esterification of volatile fatty acids d biomass origin by alcohols of biomass origin or by esterification of volatile fatty acids produced from dioxide or carbon monoxide in a microbial fuel cell by alcohols of biomass origin or not.

[Claim 8] Use according to one of the preceding claims, for reducing the emission of nitrogen oxides by petrol engines, by at least 20% of the rate incorporation of esters in the fuel consisting of petrol, the volatile fatty acid ester or esters comprising a number of carbons between 4 and 8 and any other constituents.

[Claim 9] Use according to one of the preceding claims, for reducing the emission of hydrocarbons imbulated by petrol engines by at least 20% of the rate of incorporation of esters in the fuel constituted by petrol, or the volatile fatty acid esters containing a number of carbons between 4 and 8 and any other constituents.

[Claim 10] .Use according to one of the preceding claims, for reducing the emission of particles by gasoline engines by at least 25% of the rate of incorporation of esters in the fuel constituted by gasoline, or esters of volatile fatty acids with a number of carbons between 4 and 8 and any other constituents.

[Claim 11] Use according to one of the preceding claims, characterized in that it is combined, to optimize combustion, with the use in fuel of at least one alkane with a chain length of between 4 and 10 atoms of carbon.

[Claim 12] Use according to the preceding claim, characterized in that the alkane (s) is (are) chosen from octane, iso-octane, decane and their mixtures.

[Claim 13] Use according to one of claims 11 or 12, characterized in that the alkane or alkanes are of petroleum origin or obtained from a biomass.

[Claim 14] Use according to one of claims 11 to 13, characterized in that the alkane (s) are used at a rate of between 0 and 50% by volume of fuel consisting of petrol, the ester (s) of volatile fatty acids comprising a number of carbons between 4 and 8, the alkane (s) with chain length between 4 and 10 carbon atoms, and any other constituents.

[Claim 15] Use according to one of the preceding claims, characterized in that one or more other products are added to the fuel, said products being chosen from:

- additives improving the octane number,

- lubrication improving additives,

- products reducing combustion temperatures,

- alcohols

- esters with a number of carbons greater than 8, - ethers,

- and their mixtures.