EP1321503A1 - Diesel fuel compositions containing glycerol acetal carbonates - Google Patents

Abstract

Diesel fuel composition containing carbonate(s) of glycerol acetal(s). <??>Diesel fuel composition contains: <??>(A) a major proportion of conventional diesel fuel(s); and <??>(B) carbonate(s) of glycerol acetal(s) of formula (1) and/or (2). <??>R1, R2 = H, 1-20C aliphatic, cycloaliphatic or aromatic hydrocarbyl, or an alkyl-ether chain, or R1 plus R2 may form an oxygen-containing heterocycle; <??>R3 = same as R1/R2 (except H), or a group of formula (3) and/or (4).

Description

The present invention relates to diesel fuel compositions containing oxygenates consisting of carbonates of glycerol acetals.

Improving air quality is now a top priority for all major industrialized countries. Among the emitters of referenced pollutants, transport occupies a place that demands that important steps be taken to reduce the contribution. As a result, regulatory packages have come into existence for several years, with new constraints starting in 2000, particularly specifications on fuel quality. Indeed, besides the characteristics classically specified, new regulations on the chemical composition of fuels have emerged, with the aim of limiting the precursors of certain pollutants, such as particles, tropospheric ozone reactive compounds or toxic compounds. In this context, it is obvious that all the steps aimed at improve the quality of products to offer significantly reducing blends pollutant releases are promising.

It is one of the objects of the invention to propose the use of acetal carbonates of glycerol as additives or as bases for the formulation of gas oils, leading to significant reductions in particulate emissions.

dans lesquelles :

• R1 et R2 représentent chacun un atome d'hydrogène, un radical hydrocarboné de 1 à 20 atomes de carbone, aliphatique, linéaire ou ramifié, saturé ou non, cycloaliphatique ou aromatique, ou une chaíne alkyl-éther, R1 et R2 pouvant former ensemble un radical hétérocyclique oxygéné (par exemple furanique ou tétrahydrofuranique) ;
• R3 est un radical défini comme R1 ou R2, sauf l'atome d'hydrogène, ou un radical de formule générale :
  
     où R1 et R2 sont définis comme ci-dessus.

The invention therefore provides diesel fuel compositions comprising a major proportion of at least one diesel fuel and a minor proportion of at least one glycerol acetal carbonate corresponding to one of the general formulas:

in which :

• R1 and R2 each represent a hydrogen atom, a hydrocarbon radical of 1 to 20 carbon atoms, aliphatic, linear or branched, saturated or unsaturated, cycloaliphatic or aromatic, or an alkyl-ether chain, R1 and R2 may together form a oxygenated heterocyclic radical (for example furanic or tetrahydrofuranic);
• R3 is a radical defined as R1 or R2, except the hydrogen atom, or a radical of general formula:
  
  where R1 and R2 are defined as above.

Most often, R1 and R2 are each a hydrogen atom, a methyl radical, ethyl or propyl and R3 is a methyl or ethyl radical. Preferably, the sum of number of carbon atoms of R1, R2 and R3 is at least 2.

The products considered in the invention are generally obtained from glycerol acetals of general structure:

où R1, R2 et R3 sont définis comme précédemment, R3 étant le plus souvent un radical méthyle ou éthyle.From these products, the introduction of a carbonate function is carried out for example by trans-carbonation reaction according to the scheme:

where R1, R2 and R3 are defined as above, R3 being most often a methyl or ethyl radical.

This reaction is generally carried out in a basic medium with a chosen catalyst for example, among the hydroxides, carbonates, alkoxides and hydrides of alkali or alkaline earth metals or other metals.

This reaction can also be carried out by condensation of a urethane of general formula R3-CO-NH2 on the free hydroxyl function of glycerol acetals with release of ammonia, the urethane R3-CO-NH2 which can itself be obtained easily by condensation of R3-OH alcohol with urea.

Other reactions may be envisaged to introduce a carbonate function. They are listed in an article that reviews it by taking the carbonate of dimethyl as an example: "Rewiew of Dimethyl Carbonate Manufacture and its Characteristics as a Fuel Additive "published in Energy & Fuels, vol. 11, pp. 2-29 (1997).

The glycerol acetals are themselves prepared most often by reaction, usually in an acid medium of an aldehyde or a ketone on glycerol or by transacetalization reaction. These reactions, applied to an R-OH alcohol, are represented by the diagrams below: 2 R-OH + R'CHO → (RO) 2CH-R '+ H2O 2 R-OH + (R "O) 2CH-R '→ (RO) 2CH-R' + 2 R" OH

When applied to glycerol, acetalization or transacetalization reactions are numerous. Some can be written according to the following diagrams:

• Piantadosi et coll,   J. of Am. Chem. Soc, (1958), 6613
• Gelas et coll,   Bull Soc Chim Fr, (1969), n°4, 1300
              ibid., (1970), n°6, 2341
              ibid., (1970), n°6, 2349
• Gelas et coll,   CR. Ac. Sc. Paris (1970), 218.

These reactions applied to glycerol are described for example in the following publications:

• Piantadosi et al., J. of Am. Chem. Soc., (1958), 6613
• Gelas et al., Bull Soc Chim Fr, (1969), No. 4, 1300
  ibid., (1970), No. 6, 2341
  ibid., (1970), No. 6, 2349
• Gelas et al, CR. Ac. Sc. Paris (1970), 218.

The products used in the invention may consist of one or more compounds of general formulas (1) and (2).

The introduction of these products into engine fuel compositions Diesel leads to fuels for diesel engine allowing a reduction of pollutant emissions, including particulate emissions relative to fuel not containing the products in question.

In the diesel fuel compositions according to the invention, the diesel fuel considered may be of petroleum origin or a mixture of alkyl esters derived from oils plant.

According to the invention, the diesel fuel compositions of the invention can contain glycerol acetals in various proportions. Glycerol acetal carbonate or each of the carbonates of glycerol acetals will be introduced into the diesel fuel at a concentration such that it is soluble in said diesel fuel. We use according to case proportions from 1 to 40% by volume, usually 1 to 20% by volume.

Finally, the diesel fuel compositions of the invention are generally free from Group II A metal compounds of the Periodic Table of elements.

The following examples illustrate the invention without limiting it.

EXAMPLES

In Examples 1 and 2, the synthesis of acetal carbonates is described. glycerol. Example 3 describes performance evaluation tests of compositions of gas oil closing the carbonates of glycerol acetals prepared in Examples 1 and 2.

Example 1

920 g (10 moles) of glycerol are introduced into a reactor, 790.3 g (10.96 moles) n-butyraldehyde and 24 g of an acidic resin Amberlyst 15®. The medium is brought to 54 ° C. with stirring for 7 hours, during which 120 g of n-butyraldehyde are introduced.

C = 56,7 % en masse

H = 10,1 % en masse

O = 33,2 % en masse

et qui correspond majoritairement à la formule suivante :

After returning to ambient temperature, the catalyst is removed by filtration, and the excess n-butyraldehyde and the reaction water are removed by evaporation under reduced pressure. 1165 g of a clear liquid soluble in diesel fuel are collected and the elementary analysis of which is as follows:

C = 56.7% by weight

H = 10.1% by weight

O = 33.2% by weight

and which corresponds mainly to the following formula:

C = 55,35 % en masse

H = 8,25 % en masse

O = 36,4 % en masse

et qui correspond majoritairement à la formule suivante :

In a reactor equipped with a Dean & Stark separator, 400 g of this product, 970 g (8.2 mol) of diethyl carbonate and 4 g of sodium hydride are introduced. The medium is brought to 80 ° C., then progressively to 140 ° C. while eliminating the reaction ethanol formed using the Dean & Stark separator. After 5 hours of reaction, and returning to the medium at room temperature, the catalyst is neutralized with, for example, a sufficient amount of hydrochloric acid diluted in alcohol, and after filtration, the solvents and the reagents are evaporated. excess under reduced pressure. 532 g of a clear liquid which is soluble in diesel fuel and whose elemental analysis is as follows:

C = 55.35% by weight

H = 8.25% by weight

O = 36.4% by weight

and which corresponds mainly to the following formula:

The complete operation illustrated by this example is repeated so as to have 1 liter of product.

Example 2

Example 1 is repeated replacing n-butyraldehyde with an equimolar amount of acetone. The product of the reaction corresponds mainly to the following formula:

C = 52.4 % en masse

H = 7.8 % en masse

O = 39.8 % en masse

et qui correspond majoritairement à la formule suivante :

In a reactor equipped with a Dean & Stark separator, 132 g of this product are charged with 590 g (5 moles) of diethyl carbonate and then with 1 g of sodium hydride. The medium is brought to 80 ° C., then progressively to 140 ° C. while eliminating the reaction ethanol formed using the Dean & Stark separator. After 5 hours of reaction and return of the medium to room temperature, the catalyst is neutralized with, for example, a sufficient amount of hydrochloric acid diluted in alcohol, then after filtration, the solvents and the excess reagents are evaporated off. under reduced pressure. We obtain 190 g of a clear liquid soluble in diesel fuel and whose elemental analysis is as follows:

C = 52.4% by weight

H = 7.8% by weight

O = 39.8% by weight

and which corresponds mainly to the following formula:

The complete operation illustrated by this example is repeated so as to have 1 liter of product.

Example 3

Trials were conducted to evaluate the performance of diesel compositions closing the glycerol acetals prepared in the examples precedents.

The particulate emissions measured with these fuels will be compared to those obtained with diesel alone.

• densité de l'ordre de 0,832 à 15 °C ;
• teneur en soufre de l'ordre de 300 ppm ;
• indice de cétane de l'ordre de 53 ;
• intervalle de distillation 170/366 °C.

The tests were carried out using a diesel fuel representative of Euro 2000 formulations:

• density in the range of 0.832 to 15 ° C;
• sulfur content of the order of 300 ppm;
• cetane number of the order of 53;
• distillation range 170/366 ° C.

The tests were conducted on a diesel vehicle equipped with an injection engine direct.

These tests were carried out on the cycle imposed by the European directive 70/220 / EC, as amended by Directive 98/69 / EC (called MVEG-11s Euro 2000 cycle). This cycle is composed of an urban phase (ECE cycle with a length of 4,052 km) and a extra-urban phase (EUDC cycle with a length of 6.955 km). The test results, expressed in gram of particles per kilometer, are presented on each phase of the cycle and on the complete cycle.

The results obtained are collated in the following Table 1. They are expressed in gram of particles emitted per kilometer (g / km). Evaluated fuel Particle emission (g / km) ECE Cycle EUDC cycle MVEG cycle Diesel alone 0.0635 0.0517 .0560 Diesel: 95% volume +
Product of Example 1: 5% volume 0.0449 0.0374 0.0420 Diesel: 95% volume +
Product of Example 2: 5% volume 0.0556 0.0455 0.0492

Reductions of particulate emissions with fuels according to the invention range from 12% to 29% over all conditions tested in this example.

Claims (7)

Diesel fuel composition characterized in that it comprises a major proportion of at least one diesel fuel and at least one glycerol acetal carbonate corresponding to one of the general formulas:

in which : R1 and R2 each represent a hydrogen atom, a hydrocarbon radical of 1 to 20 carbon atoms, aliphatic, cycloaliphatic or aromatic, or an alkyl-ether chain, R1 and R2 may together form an oxygenated heterocyclic radical; R3 is a radical defined as R1 or R2, except the hydrogen atom, or a radical of general formula:

where R1 and R2 are defined as above. Diesel fuel composition according to Claim 1, characterized in that , in the formula of glycerol acetal carbonate, R1 and R2 are each a hydrogen atom, a methyl, ethyl or propyl radical and R3 is a methyl or ethyl radical. . Diesel fuel composition according to claim 1 or 2, characterized in that the sum of the number of carbon atoms of R1, R2 and R3 is at least 2. Diesel fuel composition according to one of Claims 1 to 3, characterized in that it comprises a diesel fuel and a proportion of 1 to 40% by volume of at least one glycerol acetal carbonate. Diesel fuel composition according to Claim 4, characterized in that the proportion of glycerol acetal carbonate is 1 to 20% by volume. Diesel fuel composition according to one of Claims 1 to 5, characterized in that the said diesel fuel comprises a diesel fuel of petroleum origin. Diesel fuel composition according to one of claims 1 to 5 characterized in that said diesel fuel comprises a mixture of alkyl esters derived from vegetable oils.