阅读说明：本技术 特定挥发性脂肪酸酯在汽油发动机中减少排放的用途 (Use of specific volatile fatty acid esters for reducing emissions in gasoline engines ) 是由 让·伊夫·杜普雷 让·路易斯·雷韦尔 于 2019-07-26 设计创作，主要内容包括：本发明涉及挥发性脂肪酸的酯在用于汽油发动机的燃料中以减少汽油发动机的氮氧化物、未燃烧的烃以及颗粒的排放的用途,这样的酯具有在4与8之间的碳原子数。(The invention relates to the use of esters of volatile fatty acids in fuels for gasoline engines to reduce the emission of nitrogen oxides, unburned hydrocarbons and particulates from gasoline engines, such esters having a number of carbon atoms between 4 and 8.)

1. Use of at least one ester of a volatile fatty acid in a fuel for a gasoline engine, the at least one ester of a volatile fatty acid being a mono-fatty acid having an aliphatic chain of one to six carbon atoms or one of its isomers, said ester comprising a carbon number between 4 and 8, for reducing the emissions of nitrogen oxides and unburned hydrocarbons of said gasoline engine.

2. Use according to claim 1, also for reducing the emission of particles of gasoline engines.

3. Use according to claim 1 or claim 2, characterized in that the ester of volatile fatty acid(s) comprising a carbon number between 4 and 8 is used at a rate of at least 15% by volume of the fuel formed by the gasoline, the ester of volatile fatty acid(s) comprising a carbon number between 4 and 8 and possible other ingredients.

4. Use according to the preceding claim, characterized in that the ester of volatile fatty acid(s) comprising a carbon number between 4 and 8 is used at a rate of at least 30% by volume of fuel.

5. Use according to claim 3 or claim 4, characterized in that the ester of one or more volatile fatty acids comprising a carbon number between 4 and 8 is used at a rate of at least 50% by volume of fuel.

6. Use according to any one of the preceding claims, characterized in that the ester of one or more volatile fatty acids comprising a carbon number between 4 and 8 is 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.

7. Use according to any one of the preceding claims, characterized in that the ester of one or more volatile fatty acids comprising a carbon number between 4 and 8 is obtained wholly or partly by: biomass-derived volatile fatty acids are esterified by biomass-derived alcohols, or volatile fatty acids produced from carbon dioxide or carbon monoxide in a microbial fuel cell are esterified by biomass-derived or otherwise alcohols.

8. Use according to any one of the preceding claims, to reduce the emission of nitrogen oxides by the gasoline engine by incorporating in the fuel, formed from the gasoline, esters of the volatile fatty acid or acids comprising a carbon number between 4 and 8 and possibly other constituents, at a ratio of at least 20% of the esters.

9. Use according to any one of the preceding claims, to reduce the emission of unburned hydrocarbons by the gasoline engine by incorporating in the fuel, formed from the gasoline, esters of the volatile fatty acid or acids comprising a carbon number between 4 and 8 and possibly other constituents, at a ratio of at least 20% of the esters.

10. Use according to any one of the preceding claims, to reduce the emissions of particles passing through the gasoline engine by incorporating in the fuel, formed from the gasoline, esters of the volatile fatty acid or acids comprising a carbon number between 4 and 8 and possibly other ingredients, at a ratio of at least 25% of the esters.

11. Use according to any one of the preceding claims, characterized in that, in order to optimize combustion, it is used in combination with at least one alkane having a chain length between 4 and 10 carbon atoms in the fuel.

12. Use according to the preceding claim, characterized in that the alkane or alkanes are chosen from octane, isooctane, decane and mixtures thereof.

13. Use according to claim 11 or claim 12, wherein the one or more alkanes are of petroleum origin or obtained from biomass.

14. Use according to any one of claims 11 to 13, characterized in that said one or more alkanes are used in a ratio of between 0 and 50% by volume of the fuel formed by said gasoline, esters of said one or more volatile fatty acids comprising a carbon number between 4 and 8, said one or more alkanes having a chain length between 4 and 10 carbon atoms and possibly other constituents.

15. Use according to any one of the preceding claims, characterized in that one or more other products are added to the fuel, said products being selected from:

-an additive for improving the octane number,

-an additive for improving the lubrication,

-a product of lowering the combustion temperature,

-an alcohol, the alcohol being selected from the group consisting of,

-an ester comprising a carbon number greater than 8,

-an ester of (A) and (B),

-and mixtures thereof.

Detailed Description

The present invention therefore relates to the use of at least one volatile fatty acid ester comprising a carbon number between 4 and 8 in a fuel for gasoline engines to reduce the emission of nitrogen oxides and unburned hydrocarbons, and preferably also to reduce particulates from gasoline engines.

Preferably, the volatile fatty acid ester or esters comprising a carbon number between 4 and 8 are used in a proportion of at least 15% by volume, and even more preferably in a proportion of at least 20%, preferably in a proportion of at least 30%, and according to a particularly suitable embodiment in a proportion of at least 50% of the fuel formed by the ester or esters, gasoline and possibly other ingredients. These ratios make it possible to achieve particularly effective results in terms of reducing the emissions of nitrogen oxides, unburnt hydrocarbons and particulates of gasoline engines.

The short esters of one or more volatile fatty acids used according to the invention may 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 ester(s) used according to the invention are preferably obtained from biomass (biomass-derived volatile fatty acids and/or biomass-derived alcohols) in whole or in part according to any suitable method. They can be obtained in particular wholly or partly and preferably wholly by: fermentation of biomass (anaerobic fermentation of volatile fatty acids, and alcohol or acetone-butanol (aceto-butanol) fermentation of alcohols), i.e., biomass-derived volatile fatty acids are esterified by the biomass-derived alcohols. Volatile fatty acids can also be obtained from carbon dioxide or carbon monoxide in a microbial fuel cell. Thus, esters of volatile fatty acids comprising a carbon number between 4 and 8 may be obtained wholly or partly by: biomass-derived volatile fatty acids are esterified by biomass-derived alcohols, or volatile fatty acids produced from carbon dioxide or carbon monoxide in a microbial fuel cell are esterified by alcohols (which may be biomass-derived or otherwise).

Among the fuels of gasoline engines, esters of volatile fatty acids comprising a number of carbon atoms between 4 and 8 make it possible and possible in particular to:

-reducing the emission of nitrogen oxides by gasoline engines by incorporating into the fuel a ratio of at least 20% of esters, or for example, reducing by at least 10% the incorporation of 50% of esters into the fuel (the emission of nitrogen oxides can be measured in particular according to a method that meets the requirements of european regulation Euro 6, namely regulation 459/2012 of day 5, month 29, 2012); and/or

-reduction of the emission of unburned hydrocarbons by gasoline engines by incorporation of at least 20% of the ratio of esters into the fuel, or for example, reduction of at least 10% of the 50% of esters into the fuel (the emission of unburned hydrocarbons can be measured in particular according to a method that meets the requirements of european regulation Euro 6, namely regulation 459/2012 on 5/29/2012);

-and optionally, reducing the mass and number of particles emitted per kilometre traveled by the gasoline engine by incorporating into the fuel a ratio of at least 25% of ester, or, for example, reducing by at least 12.5% of 50% of ester (the mass and number of particles emitted per kilometre traveled by the gasoline engine can be measured in particular according to a method that meets the requirements of european regulation Euro 6, namely regulation 459/2012 on 5/29/2012).

Advantageously, the use according to the invention makes it possible, in addition to the uses set out above, to:

-increasing the "research" octane number of the gasoline by at least 2 points, preferably at least 3 points; and/or

-increasing the "motor" octane number of the gasoline by at least 2 points, preferably at least 3 points.

These uses are very advantageous and make it possible to obtain fuels having a significantly reduced negative impact on the environment compared to the gasoline currently used.

Other gasoline additives may be used in combination with the short esters to increase the effect and synergy of the esters of volatile fatty acids. In order to optimize the combustion, in addition to the short esters of volatile fatty acids, it is possible in particular to add to the gasoline one or more alkanes whose molecules have a number of carbon atoms between 4 and 10. The alkane may be of petroleum origin or derived from biomass. Preferably, the alkanes used according to the invention are derived from biomass. The alkane in combination with the short ester makes it possible to reduce the emissions of nitrogen oxides and unburned hydrocarbons even further. The alkane is preferably selected from octane, isooctane, decane and mixtures thereof. In fact, said alkanes tend to improve the combustion of the mixture.

The alkane is preferably used in a doping ratio of between 0 and 50% by volume of the fuel. They are preferably produced from volatile fatty acids derived from anaerobic fermentation of biomass by "Kolbe" electrolysis.

In addition to short esters, gasoline and possibly alkanes, one or more other product combinations may be added to the fuel, said products being selected from:

additives to improve the octane number, such as organometallic compounds such as MMT and ferrocene, or ethers such as ETBE or TAME, or aromatic hydrocarbons such as toluene,

lubricity improving additives such as average esters, such as hexyl valerate, hexyl hexanoate or longer esters,

products for lowering the combustion temperature, such as nitrogen compounds such as amines, urea or ammonia, possibly mixed with water,

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

- -and mixtures thereof.

The additive makes it possible to combine, in particular and with esters of volatile fatty acids, to further reduce the emissions of nitrogen oxides and unburned hydrocarbons, or indeed to improve other operating parameters of the gasoline engine.

The invention will now be illustrated by examples and test results.

Examples

Example 1:

use of 15% ethyl butyrate in RON 95 gasoline (85% gasoline-15% ethyl butyrate)

Example 2:

use of 30% ethyl butyrate in RON 95 gasoline (70% gasoline-30% ethyl butyrate)

Example 3:

use of 30% ethyl butyrate and 10% isooctane in RON 95 gasoline (60% gasoline-30% ethyl butyrate-10% isooctane)

Example 4:

use of 50% ethyl butyrate and 20% isooctane in RON 95 gasoline (30% gasoline-50% ethyl butyrate-20% isooctane)

Test results

The tests were carried out in order to evaluate the effect of using esters of volatile fatty acids comprising a number of carbon atoms comprised between 4 and 8 in fuels comprising gasoline on the emissions of nitrogen oxides, unburnt hydrocarbons and particulates of gasoline engines and also on the octane number of gasoline.

Emission tests were carried out on EP6 single cylinder spark ignition engines using the compositions of examples 1 to 4 compared to RON 95 gasoline alone.

RON octane number measurements were made in the laboratory according to the regulatory standards of french fuel specifications.

The operating protocol of the test is described below:

8 engine points were implemented for each fuel mixture to cover the use of the following driving cycles:

- -1500rpm, 4, 8, 12bar and maximum AIP

- -2000rpm, 4, 8, 12bar and maximum AIP

For each engine point, the spark advance is optimized to obtain the maximum AIP (average indicated pressure). The abundance of the mixture was adjusted to 1. It is necessary to wait several minutes to stabilize the engine's hot and exhaust emissions. Particles were analyzed on a PBS PEGASOR probe.

Table 1 lists the results associated with nox emissions.

[ Table 1]

Table 2 lists the results associated with unburned hydrocarbon emissions.

[ Table 2]

Table 3 lists the results associated with particulate emissions.

[ Table 3]

Table 4 lists the results related to octane number.

[ Table 4]

	RON octane number
		RON 95	95.1
Example 1	98.1

These results show in fact that the use of short esters of volatile fatty acids simultaneously makes it possible to:

reduction of nitrogen oxide emissions

Reduction of unburned hydrocarbon emissions

-reduction of particulate emissions.

It also makes it possible to increase the octane number of the gasoline very significantly.