EP1615985B1 - Fuel composition - Google Patents

Description

The present invention relates to a fuel composition containing, in a larger amount, a specific low alkanol-containing gasoline fuel and a smaller amount of selected gasoline additives.

Carburetors and intake systems of gasoline engines, but also injection systems for fuel metering, are increasingly burdened by impurities caused by dust particles from the air, unburned hydrocarbon residues from the combustion chamber and the crankcase vent gases conducted into the gasifier.

These residues shift the air-fuel ratio at idle and in the lower part-load range, making the mixture leaner, incomplete combustion and, in turn, increasing the proportion of unburned or partially combusted hydrocarbons in the exhaust gas and increasing gasoline consumption.

It is known that to avoid these disadvantages, fuel additives are used for keeping valves and carburetors or injection systems of gasoline engines clean (cf., for example: M.Rossenbeck in catalysts, surfactants, mineral oil additives, ed. J. Falbe, U. Hasserodt, p. 223, G. Thieme Verlag, Stuttgart 1978 ).

Furthermore emerges in gasoline engines of older design, the problem of valve seat wear when operating with unleaded gasoline. Against this, valve seat wear-inhibiting additives based on alkali metal or alkaline earth metal compounds have been developed.

Modern gasoline engines require for a trouble-free use fuels with a complex property profile, which can be guaranteed only in combination with appropriate gasoline additives. Such gasoline fuels usually consist of a complex mixture of chemical compounds and are characterized by physical quantities. However, the interaction between gasoline fuels and corresponding additives is still in need of improvement in the case of the known fuel compositions with regard to the cleansing or keeping clean and the valve seat wear-inhibiting effect.

The WO 01/85874 discloses a fuel composition containing a gasoline having a sulfur content of max. 150 ppm, an olefin content of max. 21 vol .-%, a benzene content of max. 1.0 vol .-%, an aromatic content of max. 42% by volume, a carrier oil mixture and a detergent additive. The fuel composition may include alcohols such as methanol (maximum 3% by volume), ethanol (maximum 5% by volume), isopropanol (maximum 10% by volume), t-butanol (maximum 7% by volume) or isobutanol (maximum 10% by volume).

Comparable maximum alcohol contents are in the older one WO 03/074637 for gasoline compositions which are additized with specific mixtures of detergent additive and carrier oil.

The DD 140 359 describes low-lead fuels, containing 5-30 vol .-% of an additive of a mixture of methanol methyl tert-butyl ether and a boiled between 373 and 473 Kelvin alcohol fraction.

The older one WO 03/076554 describes the use of specific hydrocarbyl amines to reduce injector deposits in gasoline engines, wherein the unleaded gasoline fuels used may contain 0.1-15% by volume of additives such as methanol, ethanol and MTBE.

The object of the present invention was therefore to find a more effective gasoline-petrol fuel additive composition. In particular, more effective additive formulations should be found.

• (a) Mono- oder Polyaminogruppen mit bis zu 6 Stickstoffatomen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
• (f) Polyoxy-C2- bis C4-alkylengruppierungen, die durch Hydroxylgruppen, Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat, oder durch Carbamatgruppen terminiert sind;
• (h) aus Bernsteinsäureanhydrid abgeleitete Gruppierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen; und
• (i) durch Mannich-Umsetzung von substituierten Phenolen mit Aldehyden und Mono- oder Polyaminen erzeugte Gruppierungen.

Accordingly, there has been found a gasoline composition according to claim 1 which contains at least one detergent gasoline additive, said gasoline additive having at least one hydrophobic hydrocarbon radical having a number average molecular weight (MN) of 85 to 20,000 and at least one polar moiety, and wherein said fuel composition also has a content of methanol, ethanol and mixtures thereof of from 10 to 75% by volume, the polar grouping being selected from:

• (a) mono- or polyamino groups having up to 6 nitrogen atoms, at least one nitrogen atom having basic properties;
• (f) polyoxy-C 2 to C 4 alkylene moieties terminated by hydroxyl groups, mono- or polyamino groups, wherein at least one nitrogen atom has basic properties, or terminated by carbamate groups;
• (h) succinic anhydride-derived moieties having hydroxy and / or amino and / or amido and / or imido groups; and
• (i) moieties generated by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines.

The alkanol content is, based on the total volume of the fuel composition 10 to 75 vol .-%, preferably 10 to 65 vol .-%, in particular 20 to 55 vol .-%, such. B. 30 - 40 vol .-% or 40 - 50 vol .-%.

The content of other alcohols and ethers in gasoline is usually relatively low. Typical maximum contents are 7% by volume for tert-butanol, 10% by volume for isobutanol and 15% by volume for ethers having 5 or more C atoms in the molecule.

The aromatic content of the gasoline is preferably not more than 40% by volume, in particular not more than 38% by volume. Preferred ranges for the aromatic content are from 20 to 42% by volume, in particular from 25 to 40% by volume.

The sulfur content of the gasoline is preferably not more than 100 ppm by weight, in particular not more than 50 ppm by weight. Preferred ranges for the sulfur content are from 0.5 to 150 ppm by weight, in particular from 1 to 100 ppm by weight.

In a preferred embodiment, the gasoline has an olefin content of not more than 21% by volume, preferably not more than 18% by volume, in particular not more than 10% by volume. Preferred ranges for the olefin content are from 6 to 21% by volume, in particular from 7 to 18% by volume.

In a further preferred embodiment, the gasoline has a benzene content of not more than 1.0% by volume, in particular not more than 0.9% by volume. Preferred ranges for the benzene content are from 0.5 to 1.0% by volume, in particular from 0.6 to 0.9% by volume.

In a further preferred embodiment, the gasoline has an oxygen content of at most 2.7 wt .-%, preferably from 0.1 to 2.7 wt .-%, especially from 1.0 to 2.7 wt .-%, in particular from 1.2 to 2.0 wt .-%, on.

Particular preference is given to a gasoline fuel which simultaneously has an aromatics content of not more than 38% by volume, an olefin content of not more than 21% by volume, a sulfur content of not more than 50 ppm by weight, a benzene content of not more than 1.0% by volume and a Having oxygen content of 1.0 to 2.7 wt .-%.

Vol.% Above - for olefin, benzene, aromatics and oxygen content are in each case based on the volume of the mineral gasoline component, d. H. without additives and without alkanol.

The summer vapor pressure of the gasoline is usually not more than 70 kPa, in particular 60 kPa (each at 370C).

The research octane number ("RON") of the gasoline is typically 90 to 100. A common range for the corresponding engine octane number ("MOZ") is 80 to 90.

The specified specifications are determined by conventional methods (DIN EN 228).

The hydrophobic hydrocarbon radical in the gasoline fuel additives, which provides sufficient solubility in the fuel, has a number average molecular weight (Mn) of 85 to 20,000, especially from 113 to 10,000, especially from 300 to 5000. As a typical hydrophobic hydrocarbon radical, in particular Compound with the polar groups (a), (c), (h) and (i), come the polypropenyl, polybutenyl and polyisobutenyl each having Mn = 300 to 5000, in particular 500 to 2500, especially 750 to 2250, in consideration.

As individual gasoline-based gasoline additives, the following are mentioned.

Mono- or polyamino (a) -containing additives are preferably polyalkene mono- or Polyalkenpolyamine based on polypropene or highly reactive (ie with predominantly terminal double bonds - usually in the alpha and beta position) or conventional (ie with predominantly central double bonds) polybutene or Polyisobutene having Mn = 300 to 5000. Such additives based on highly reactive polyisobutene, which from the polyisobutene, which may contain up to 20 wt .-% of n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines such as dimethylaminopropylamine , Ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine can be prepared, in particular from EP-A 244 616 known. If one starts with the preparation of the additives of polybutene or polyisobutene with predominantly central double bonds (usually in the beta and gamma position), the preparation route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions at. For amination, the same amines as described above can be used for the reductive amination of the hydroformylated highly reactive polyisobutene. Corresponding additives based on polypropene are especially in the WO-A 94/24231 described.

Further preferred monoamino groups (a) containing additives are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular WO-A 97/03946 are described.

Further preferred monoamino groups (a) -containing additives are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as are described in particular in US Pat DE-A 196 20 262 are described.

Polyoxy-C ₂ - to C ₄ -alkylene additives (f) are preferably polyethers or polyetheramines which are obtainable by reaction of C ₂ - to C ₆₀ alkanols, C ₆ - to C ₃₀ alkanediols, mono- or di-C ₂ C ₃₀ -alkylamines, C ₁ -C ₃₀ -alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. Such products are used in particular EP-A 310 875 . EP-A 356 725 . EP-A 700 985 and US Pat. No. 4,877,416 described. In the case of polyethers, such products also meet carrier oil properties. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

Succinic anhydride-derived groupings containing hydroxyl and / or amino and / or amido and / or imido groups (h) are preferably corresponding derivatives of polyisobutenyl succinic anhydride obtained by reacting conventional or highly reactive polyisobutene having Mn = 300 to 5000 with maleic anhydride thermal ways or via the chlorinated polyisobutene are available. Of particular interest here are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine. Such gasoline additives are particularly useful in US Pat. No. 4,849,572 described.

By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated groupings (i) containing additives are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols may be derived from conventional or highly reactive polyisobutene having Mn = 300 to 5,000. Such "polyisobutene-Mannich bases" are particularly in the EP-A 831 141 described.

For a more detailed definition of the individual listed petrol additives, reference is made here expressly to the disclosures of the abovementioned prior art documents.

The fuel composition of the invention may further contain other conventional components and additives. Carrier oils without pronounced detergent action should be mentioned here in the first place, for example mineral carrier oils (base oils), in particular those of the viscosity class "Solvent Neutral (SN) 500 to 2000", and synthetic carrier oils based on olefin polymers with Mn = 400 to 1800, above all based on polybutene or polyisobutene (hydrogenated or unhydrogenated), polyalphaolefins or polyinteralalefins.

Suitable solvents or diluents (when providing additive packages) are aliphatic and aromatic hydrocarbons, e.g. Solvent naphtha, into consideration.

Further customary additives are corrosion inhibitors, for example based on film-forming ammonium salts of organic carboxylic acids or of heterocyclic aromatics in non-ferrous metal corrosion protection, antioxidants or stabilizers, for example based on amines such as p-phenylenediamine, dicyclohexylamine or derivatives thereof or on phenols such as 2,4-di tert-butylphenol or 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid, demulsifiers, antistatic agents, metallocenes such as ferrocene or methylcyclopentadienyl manganese tricarbonyl, lubricity additives such as certain fatty acids, alkenyl succinic esters, bis (hydroxyalkyl) fatty amines, hydroxyacetamides or castor oil and dyes (markers). Sometimes amines are also added to lower the pH of the fuel.

For the fuel composition according to the invention, in particular, combinations of the described gasoline with a mixture of gasoline fuel additives with the polar grouping (f) and corrosion inhibitors and / or lubricity improvers based on carboxylic acids or fatty acids, which as monomeric and / or dimeric species may be considered. Typical mixtures of this type include polyisobutene amines in combination with alkanol-initiated polyethers such as tridecanol or isotridecanol butoxylates or propoxylates, polyisobutene amines in combination with alkanol-initiated polyetheramines such as tridecanol or isotridecanol butoxylate ammonia reaction products and alkanol-initiated polyether amines such as tridecanol or isotridecaol butoxylate ammonia reaction products in combination with alkanol-started polyethers such as tridecanol or isotridecanol butoxylates or propoxylates, each together with the said corrosion inhibitors or lubricity improvers.

The aforementioned gasoline additives with the polar groups (a), (f), (h) and (i) and the other components mentioned are added to the gasoline and unfold their effect there. The components or additives can be added to the gasoline fuel individually or as a previously prepared concentrate ("additive package").

The above gasoline additives with the polar groups (a), (f), (h) and (i) are the gasoline usually in an amount of 5 to 5000 ppm by weight, especially 5 to 3000 ppm by weight, especially 10 to 1000 ppm by weight, added. The other components and additives mentioned are added, if desired, in customary amounts.

Surprisingly, with the fuel composition of the present invention, with significantly less detergent or valve seat wear-inhibiting agent, the same cleaning or valve seat wear-inhibiting effect can be achieved as in comparable fuel compositions without low alkanol addition. Furthermore, when using the same amounts of detergent or valve seat wear-inhibiting agent in the inventive fuel composition compared to conventional fuel compositions surprisingly results in a significantly better cleansing or purifying or valve seat wear-inhibiting effect.

Furthermore, the fuel composition according to the invention additionally has the advantage that fewer deposits are formed in the combustion chamber of the gasoline engine and that less additive is introduced into the engine oil via the fuel dilution.

Further objects of the invention relate

1. i) the use of a lower alkanol in low-sulfur gasoline fuels to improve the effect of a detergent-effect additive as defined in the claims and
2. ii) the use of a combination of lower alcohol and at least one detergent additive to reduce combustion chamber deposits and / or to reduce deposits in the intake system of a gasoline engine; as defined in the claims.

The following examples are intended to illustrate the invention without, however, limiting it.

Examples:

The gasoline additive used was a commercial additive package comprising 60% by weight of detergent additive polyisobuteneamine (Mn = 1000 g / mol) and 32% by weight of carrier oil (tridecanol etherified with 22 units of butylene oxide).

As gasoline fuels, those listed below were used with the specified specification, with OK 1 (parameters see Table 1) representing a typical commercial fuel. Table 1 specification OK 1 Aromatic content [% by volume] 39.8 Paraffin content [Vol .-%] 47.7 Olefin content [Vol .-%] 12.5 Sulfur content [ppm by weight] 35 Density [15 ° C] [kg / m ³ ] 743.6 Initial boiling point 34.5 ° C 10% volume 50 ° C 50% volume 85 ° C 90% volume 150.5 ° C Final boiling point 189.0 ° C OK 2 = OK 1 + 10 vol.% EtOH
OK 3 = OK 1 + 50 vol.% EtOH

Preparation of fuel compositions Example 1 (comparative experiment)

150 or 200 mg of additive package were dissolved in 1 kg of OK 1 according to Table 1.

Example 2 (according to the invention)

Example 1 was repeated, but using OK 2 instead of OK 1.

Example 3 (according to the invention)

Example 1 was repeated but using OK 3 instead of OK 1.

Application engineering investigations Example 4

Gasoline fuels according to Examples 1 to 3 were examined for their influence on the intake system cleanliness (IVD) and on the combustion chamber deposits (TCD). This was done with the help of engine tests in bench tests with a Mercedes-Benz engine M102 E according to CEC F-05-A-93. The IVD values for additized and non-additized fuels are summarized in Table 2 below.

Furthermore, in the same series of experiments, the amount of combustion chamber deposits (TCD) was determined for each of the 4 cylinders of the engine. The respective average value is also given in Table 2. To determine the TCD value, the procedure was analogous to the procedure CEC F-20-A-98. Table 2 fuel OK 1 OK 2 OK 3 Additive amount [mg / kg] 0 150 200 0 150 200 0 150 200 IVD ¹⁾ [mg / valve] 269 85 23 293 98 15 239 31 3 TCD ²⁾ [mg / cylinder] 1778 1864 1807 1677 1668 1713 1056 1248 764 ¹⁾ Intake Valve Deposits
²⁾ Total Combustion Deposits

As can be seen from Table 2, when larger quantities of ethanol (ie> 10%) are added to the gasoline, a surprisingly small formation of valve or combustion chamber (cylinder) deposits is observed.

Claims (11)

1. A gasoline fuel composition having a maximum sulfur content of 150 ppm by weight, comprising 5 to 5000 ppm by weight of at least one gasoline fuel additive having detergent action, wherein this gasoline fuel additive has at least one hydrophobic hydrocarbon radical having a number-average molecular weight (Mn) of from 85 to 20 000 and at least one polar moiety, wherein the fuel composition also has a content of methanol, ethanol or mixtures thereof of from 10 to 75% by volume, and wherein the polar moiety is selected from:

   (a) mono- or polyamino groups having up to 6 nitrogen atoms, of which at least one nitrogen atom has basic properties,

   (f) polyoxy-C₂-C₄-alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, in which at least one nitrogen atom has basic properties, or by carbamate groups,

   (h) moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups and

   (i) moieties obtained by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines.
2. A gasoline fuel composition according to claim 1, comprising, as a gasoline fuel additive having polar moieties (a), polyalkenemono- or polyalkenepolyamines based on polypropene, polybutene or polyisobutene having Mn = from 300 to 5000.
3. A gasoline fuel composition according to claim 1, comprising, as a gasoline fuel additive having polar moieties (f), polyethers or polyetheramines obtainable by reacting C₂-C₃₀-alkanols, C₆-C₆₀-alkanediols, mono- or di- C₂-C₃₀-alkylamines, C₁-C₃₀-alkylcyclohexanols or C₁-C₃₀-alkylphenols with from 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines.
4. A gasoline fuel composition according to claim 1, comprising, as a gasoline fuel additive having polar moieties (h), derivatives of polyisobutenylsuccinic anhydride obtainable by reacting conventional or highly reactive polyisobutene having Mn = from 300 to 5000 with maleic anhydride by a thermal route or via the chlorinated polyisobutene.
5. A gasoline fuel composition according to claim 1, comprising, as a gasoline fuel additive having polar moieties (i), reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines.
6. A gasoline fuel composition according to any of claims 1 to 5, comprising a gasoline fuel having a maximum olefin content of 21% by volume based on the volume of a nonadditized alcohol-free gasoline fuel.
7. A gasoline fuel composition according to any of claims 1 to 6, comprising a gasoline fuel having a maximum benzene content of 1.0% by volume based on the volume of a nonadditized alcohol-free gasoline fuel.
8. A gasoline fuel composition according to any of claims 1 to 7, comprising a gasoline fuel having a maximum oxygen content of 2.7% by volume based on the volume of a nonadditized alcohol-free gasoline fuel.
9. A gasoline fuel composition according to any of claims 1 to 8, comprising a gasoline fuel having a maximum aromatics content of 42% by volume based on the volume of a nonadditized alcohol-free gasoline fuel.
10. The use of at least one C₁-C₆-monoalkanol, or mixtures thereof, in a proportion of from 10 to 75% by volume in low-sulfur gasoline fuels having a maximum sulfur content of 150 ppm by weight to improve the action of an additive having detergent action, wherein the additive has at least one hydrophobic hydrocarbon radical having a number-average molecular weight (Mn) of 85 to 20 000 and at least one polar moiety selected from

    (a) mono- or polyamino groups having up to 6 nitrogen atoms, of which at least one nitrogen atom has basic properties,

    (f) polyoxy-C₂-C₄-alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, in which at least one nitrogen atom has basic properties, or by carbamate groups,

    (h) moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups and

    (i) moieties obtained by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines;

    wherein the additive action can be determined to CEC F-05-A-93 or CEC F-20-A-98 and wherein the additive is present in an amount of 5 to 5000 ppm by weight.
11. The use of a combination of at least C₁-C₆-monoalkanol or mixtures thereof, and at least one additive having detergent action as defined in claim 1 to reduce combustion chamber deposits, determinable to CEC F-20-A-98, and/or to reduce deposits in the intake system of a gasoline engine, determinable to CEC F-05-A-93, wherein the additive having detergent action is metered into a gasoline fuel in an amount of 5 to 5000 ppm by weight and the alkanol in a content of 10 to 75% by volume.