EP0012345A1 - Fuel oils and their application - Google Patents

Abstract

A fuel especially a fuel for an automobile, internal combustion engine or a diesel engine comprising a hydrocarbon water and emulsifier wherein the emulsifier is a non-ionic emulsifier and comprises the addition product of ethylene oxide or propylene oxide and a carboxylic acid amide with 9 to 21 carbon atoms.

Description

The invention relates to fuels for Vorhrcnnungskraftmaschinen such as gasoline and diesel engines as well as rotary piston machines and turbines, which contain emulsifiers or emulsifier mixtures and water and optionally alcohols in the fuels customary for the respective units.

The use of water and emulsifiers in fuels to promote combustion has already become known (DOS 1 545 509 and DOS 2 633 452). For example, the knocking behavior of gasoline in higher compression engines is influenced more positively by water than by the frequently read-out methanol additive (Motorzeitschrift, Jahrg. 37, Kr.5, S 187 (1976); SAE publication 750 123). In the case of the emulsifiers used to date, however, a number of disadvantages, some of which were considerable, had to be accepted, in particular the poor stability to cold.

Fuels for internal combustion engines have now been found which contain a nonionic emulsifier, water and optionally an alcohol, which are characterized in that they contain, as emulsifier, an adduct of ethylene oxide or propylene oxide with a carboxamide having 8-22 carbon atoms.

in der

• R für einen gegebenenfalls substituierten, geradkettigen oder verzweigten oder cyclischen, gesättigten oder ungesättigten Kohlenwasserstoffrest steht,
• Y die Gruppierung
  
  bedeutet, wobei
• R₂ Wasserstoff oder Methyl bedeutet, und in der
• n für eine ganze Zahl von 1 bis 50 steht, und
• R₁ Wasserstoff darstellt oder die Bedeutung der Gruppierung (̵Y)̵_nH hat,
• 0 - 20 Gew.-% eines 1 - 8 Kohlenstoffatome enthaltenden Alkohols, der geradkettig oder verzweigt, gesättigt oder ungesättigt sein kann, und
• 0,5 - 35 Gew.=% Wasser.

The fuels according to the invention preferably contain 40-95% by weight of hydrocarbons, 0.5-6% by weight of a nonionic emulsifier of the formula

in the

• R represents an optionally substituted, straight-chain or branched or cyclic, saturated or unsaturated hydrocarbon radical,
• Y the grouping
  
  means where
• R _{2 is} hydrogen or methyl, and in the
• n stands for an integer from 1 to 50, and
• R _{1 represents} hydrogen or has the meaning of the grouping (̵Y) ̵ _n H,
• 0-20% by weight of an alcohol containing 1-8 carbon atoms, which may be straight-chain or branched, saturated or unsaturated, and
• 0.5 - 35% by weight =% water.

A fuel composition with 60-95% by weight of a hydrocarbon or hydrocarbon mixture, 1.0-3.5% by weight of one or more emulsifiers of the formula (I), optionally 0.5-10% by weight of one, is particularly preferred C ₁ -C ₈ alcohol and water as the rest.

The hydrocarbons contained in the fuels according to the invention are generally the mixtures customary for this purpose, such as those with their physical data in DIN regulation 51 600 or in the United States Federal Specification VV-M-561 a-2, October 30, 1954 , Marked are. They are aliphatic hydrocarbons from gaseous, dissolved butane to C ₂₀ hydrocarbons (as a residual fraction of diesel oil), e.g. cycloaliphatic, olefinic and / or aromatic hydrocarbons, natural naphthenic or refined technical hydrocarbons. The compositions according to the invention preferably contain no lead alkyls and similarly toxic additives.

in welcher R, R₂ und n die oben angegebene Bedeutung haben.The nonionic emulsifier is preferably a fatty acid amide, which is to be thought of by adding 1 to 50 mol of ethylene oxide or propylene oxide to a fatty acid amide, with the formula

in which R, R ₂ and n have the meaning given above.

The radical R generally means the radical of a saturated or unsaturated carboxylic acid, which can be varied within the broadest limits with regard to its molecular structure. Examples include fatty acids, such as Octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, arachidic acid or oleic acid, erucic acid, ricinoleic acid or mixtures thereof, as described e.g. in coconut oil, palm oil, sunflower oil, safflower oil, soybean oil, castor oil, whale oil, fish oil, tallow fat, pork fat.

The proposed emulsifiers of the formula (I) are already known (cf. M.J. Schick, Nonionic Surfactans, Volume 1, pages 209-211; M.Dekker, New York 1976); they are physiologically very compatible (use in hand washing detergents) and biodegradable. The raw materials from the fat side are available in large quantities and can also be multiplied for a long time, since they are independent of fossil deposits. Of course, synthetic acids can also be used, such as those formed in the paraffin oxidation or in the oxidation of α-olefins or tri- and tetrapropylene. If the amides are produced from the natural triglycerides, the monoglycerides of these fats can still be present if only two of the fatty acid residues of the triglyceride are used for the amide formation.

The degree of oxyethylation, i.e. The type and number of groupings Y of the formula (I) can be varied within wide limits. Advantageously, the emulsifiers used are compounds of the formula (I) which are adducts of 1-3 moles of ethylene oxide with 1 mole of carboxylic acid amide and / or of 5-25 moles of ethylene oxide and / or propylene oxide with 1 mole of carboxylic acid amide. For example, the 1-3: 1 adduct content can be 15-70% by weight and the 5-25: 1 adduct content can be 30-85% by weight of the fuel according to the invention. The emulsifier is particularly preferably the adduct of 1-2 moles of ethylene oxide with 1 mole of fatty acid amide (optionally mixed with production-related proportions of a fatty acid monoglyceride) and / or the adduct of 5-10 moles of ethylene oxide and / or propylene oxide with 1 mole of fatty acid amide and optionally the adduct of 20 - 30 moles of ethylene oxide with 1 mole of fatty acid amide.

The emulsifiers are most advantageously produced via the fatty acids and ethanolamine (cf. M. Schick, Nonionic Surfactants, loc. Cit., Pp. 213-214). These components can be used to produce a fatty acid amide according to the invention containing 1 mole of ethylene oxide and having a very high degree of purity by elimination of water at 160-180 ° C. in about 60-90 minutes. If one starts from the fatty acid amide (see M.Schick, Nonionic Surfactants, loc. Cit., P.213), 1 mol of ethylene oxide is added, advantageously at elevated temperature, for example at 100 - 140 ^o C, possibly with weakly acidic or weakly basic catalysis. To achieve greater uniformity of the products, it may be advisable to work with the customary oxyalkylation catalysts, such as sodium hydroxide, sodium methylate, potassium hydroxide, from 1: 1 adduct and add the desired amount of ethylene oxide under pressure. If natural fat is assumed, this is reacted with 2 moles of ethanolamine. After about 2 - 5 hours and about 140 - 180 ° C reaction temperature generally no ethanolamine and no triglyceride can be detected. This 1: 2 molar mixture of fatty acid mono- ^g lycerid.und fatty acid amide 1: 1 ethylene oxide adduct can be advantageously used in an amount of 15-70 wt .-% of the nonionic emulsifier can be used.

The non-ionic emulsifiers can contain impurities from the industrial production, which result from impurities in the preliminary product, e.g. come from the ethylene oxide, are caused by moisture or come from the oxyethylation catalyst. These are preferably polyethylene glycols, which can be responsible for the deterioration in the emulsion quality and for the formation of an aqueous sediment. If they are present in the emulsifiers in amounts of more than 1%, it is advisable to remove them by one of the known cleaning operations for nonionic emulsifiers, e.g. according to DE-PS 828 839. For this purpose, a new cleaning method, as proposed in patent application P 28 54 541.7, is preferably suitable on an industrial scale.

The lower alcohols are used in the fuels according to the invention in order to control the spontaneity of the emulsion, the low-temperature stability and the temperature dependence in the emulsification of the water. The spontaneity can generally be brought about with the aid of mixed emulsifiers of different ionogenicity. Since only nonionic and residue-free combustible emulsifiers can be used in motor fuel for corrosion reasons without difficulty, it must be used as are said to be extremely surprising that spontaneous water-in-oil emulsions are obtained with the emulsifiers according to the invention. As a result, the fuels according to the invention have a considerably improved stability to cold, which consists not only in preventing the formation of ice crystals, but also in the failure to form gel structures which can cause an uncontrolled increase in viscosity.

Straight-chain or branched aliphatic alcohols and cycloaliphatic alcohols may be mentioned as alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, amyl alcohol, iso-amyl alcohol, hexyl alcohol, 1,3-dimethyl-butanol, cyclohexanol, methylcyclohexanol, Octanol, 2-ethylhexanol. Mixtures of these alcohols can also be used well. Alcohols which are readily available industrially are preferably used, e.g. Methanol, ethanol, isopropanol, isobutanol, 2-ethylhexanol.

The fuel emulsion according to the invention is produced by stirring the water into the solution of the emulsifier in the hydrocarbon which may contain alcohol, preferably no further machines providing distribution energy being used. As a modification of this, the emulsifier, optionally also the alcohol, can be distributed over petrol and / or water.

After formation of the emulsion, it is expedient not to allow the viscosity of the emulsion to rise to much higher values than 1 ₀ mPa s (vgl.DIN regulation 9040), as a viscosity of about 100 PA s can already lead to the normal Filters, pumps and nozzles of motor vehicles can no longer be passed without problems. It is therefore advisable to maintain a viscosity of 5 m PA s for the fuels according to the invention, for example for gasoline emulsions below 2 m _PA s. The viscosity should not increase significantly even when it cools down to approx. -15 ° C, and the emulsion should remain stable.

The monoamides to be used as emulsifiers for the fuels according to the invention, in particular those of the formula (II), have a pronounced rust protection effect. In contrast, methylpolyether amides previously used, for example, are largely ineffective. The other emulsifiers described so far for use in fuels show a rather increased rust formation in the presence of water - probably due to their degreasing effect.

Furthermore, the type of emulsifier according to the invention does not lead to increased swelling or detachment, neither in the plastic parts coming into contact with the fuel system nor in the paint surfaces, as can be observed with the esters of the polyethers.

Another advantage of the fuels according to the invention is that the use of lead tetraalkylene with the required extremely low value for the maximum workplace concentration (MAK value) of 0.01 ppm can be avoided. Furthermore, the "fluids" (or so-called scavenger, cf. Chemiker-Zeitung 97 (1973) No. 9, p. 463) necessary for removing the lead oxide in the engine can be omitted, which are classified in Class III B in the last accident prevention regulations (accident prevention regulations of the professional association of the chemical industry, appendix 4, list of MAK values from 01.10.1978).

Furthermore, the lowering of the temperature of the combustion process reduces the amount of pollutants in the exhaust gas (e.g. the NO content) and because of this "built-in cooling", the "lean" mixture can be used economically. It is no longer necessary to lower the combustion chamber temperature by means of a "rich" mixture, which corresponds to an unnecessarily increased fuel consumption. Since the additives are emulsifiers, aggregate contamination due to their detergent effect is also avoided.

The ratio of fuel that is used and that is only required from a technical point of view is, of course, particularly unfavorable in the case of high-speed drive units, such as, for example, in the case of the Wankel engine and turbines, which develop their driving force only at high speeds. In addition, the necessary heat of combustion quickly leads to heat accumulation problems and thus to unfavorable exhaust gas values. Here is the use of it Fuel-water emulsion according to the invention is particularly suitable for achieving a more favorable specific consumption and for solving the heat and exhaust gas problems.

Another advantage of the fuels according to the invention which contain emulsifiers and water and, if appropriate, alcohols is that their electrostatic charge is greatly reduced, so that a substantial danger when handling fuels is reduced (cf. Haase, static electricity as a danger, Verlag Chemie, Weinheim / Bergstrasse 1968, especially pages 69, 96 - 99, 114 and 115). The electrostatic charge of the fuels according to the invention is so low that dangerous discharges can no longer occur. The normal gasoline used shows values around 1.10 ¹² Ω.am for the specific volume resistance at 20 ° C, whereas the fuel according to the invention generally has a volume resistance of less than 1.10 ¹⁰ Ω.cm, for example ₁ . ₁₀ ⁷ to 1.10 ¹⁰ Ωcm, on. The specific volume resistance of the fuels according to the invention is 1.10 to 9.10 ⁹ Ω · cm. At values below 10 ¹⁰ Ω · cm there is no longer any danger from electrostatic charging when filling, decanting and draining.

Surprisingly, despite the sometimes considerable water content, the combustibility of the fuel - even with a reduction in soot development - is maintained. For diesel fuels composed according to the invention, the tolerance limit in the fuel-air ratio is shifted far upwards to the very annoying, sooty smoke of the diesel vehicles.

The ignition of the fuel emulsions of the invention is in no way impaired, so that vehicles even after he vielwöchi ^g, jump when starting outdoor verbrachter break without delay. This operational safety is also achieved by the excellent storage stability of the emulsions to be used according to the invention, which do not settle water in the carburetor, in the gasoline pump or in the tank - not even in small quantities. As a result, the known difficulties when starting and the misfires when driving are eliminated. Previously known emulsifier systems tend - particularly because of the by-products they contain - to form these so-called water sumps.

Finally, an improvement in the octane number is also achieved by using the fuels according to the invention.

Unless stated otherwise, the percentages contained in the following examples are percentages by weight.

example 1

In a normal commercially available fuel quality (s ^p _e-D zifischer urchgangswiderstand 1.1012S2. Cm) to 2.4% of a nonionic, purified by polyethylene glycol oleic acid amide with 7 moles of ethylene oxide (adduct of 7 moles of ethylene oxide and 1 mole of oleic acid amide), 0.6% a coconut fatty acid amide dissolved with 1 mol of ethylene oxide (free of ester components) and 1.5% isobutanol.

While stirring with a stirrer (approx. 200-300 rpm), 25% water is run into the gasoline emulsifier solution (70.5% normal gasoline). When the emulsion has been thoroughly circulated, an opal milky fuel is ready for use. At 900x magnification only microscopic, fine droplets are visible under the microscope, and no islands of water that are pushed wide by the slide. The fuel produced in this way has a volume resistance of 3.10 ⁹ Ω · cm.

The viscosity at 20 ° C was 0.96 m PA s and the throughput times through a Bosch gasoline filter did not differ from that of an equal amount of gasoline. An Opel Kadett with an output of 45 hp and a displacement of 1.1 liters was tested on an HPA tester (roller test bench) for 15 minutes at 100 km / h speed and with a resistance of 20 kg on the rollers.

The fuel was fed to the carburetor separately from a measuring vessel. In accordance with the higher surface viscosity and higher density, the idle and full load nozzles have been slightly enlarged. The outside temperature temperature was 14 ° C. The following consumption was determined from the measured fuel quantity and the number of kilometers traveled at approx. 100 km / h:

The car could be driven with one tank of the fuel emulsion and restarted immediately after being left standing. The CO exhaust gas values were 2.5 vol%.

Example 2

3% of the emulsifier oleic acid amide used in Example 1 with 7 mol of ÄO (= ethylene oxide) is dissolved in 72% normal gasoline and processed into an emulsion of the same quality as in Example 1 by slowly stirring in 25% water. This emulsion can be used for carburetor engines at temperatures above 15 ° C.

Example 3

If 0.3% of the 1: 1 adduct of castor oleic acid amide and ethylene oxide (ÄO) is added to the fuel emulsion from Example 2, the serviceability remains at 0 ° C.

Example 4

To produce a fuel, a mixture of 70% unleaded normal gasoline, 2.4% oleic acid amide with 7 moles of ethylene oxide, 0.6% technical coconut fatty acid amide with 1 mole of AO (prepared by heating 1 mole of coconut oil with 2 moles of ethanolamine to 160 ⁰ C until no free amine could be titrated) and 5% of a mixture of methanol and isobutanol (4: 1) emulsified with good stirring at outside temperatures of approx. 15 ° C 22% water.

This gave a stable, milky opal-emulsion of less than 1 m PA's had and also at -10 ⁰ C yet formed a viscosity no gel-like streaks.

This fuel was used to fuel a Fiat 128 motor vehicle with 55 hp and a displacement of 1180 cc that had previously been run on super fuel. With a slight increase in the suction pressure in the carburetor by partially activating the choke, the vehicle could be used for lively city traffic without any noticeable loss of driving characteristics. An accelerating knock (ringing), as is found in gasoline of insufficient quality, was not observed when the engine was cold or warm. The low contamination of the candles after the short-distance traffic was striking.

Example 5

• Eine Mischung aus 67 % eines bleifreien Normalkraftstoffes, 2,25 % ölsäureamid mit 7 Mol Äthylenoxid (gereinigt), 0,75 % eines technischen Kokosfettsäureamids mit 1 Mol Äthylenoxid (hergestellt durch Amidierung von 1 Mol Kokosfett mit 2 Mol Äthanolamin bei 160 - 170°C) und 5 % eines Alkoholgemisches aus Methanol, Isobutanol, 2-Äthylhexanol (17:2:1) wurde bei 11 - 14°C (Erdtanktemperatur) mit 25 % Wasser unter Rühren emulgiert.

A 1.7 liter Opel record was set with the fuel produced as follows:

• A mixture of 67% of a lead-free normal fuel, 2.25% oleic acid amide with 7 moles of ethylene oxide (purified), 0.75% of a technical coconut fatty acid amide with 1 mole of ethylene oxide (produced by amidating 1 mole of coconut fat with 2 moles of ethanolamine at 160 - 170 ° C) and 5% of an alcohol mixture of methanol, isobutanol, 2-ethylhexanol (17: 2: 1) was emulsified at 11-14 ° C. (tank temperature) with 25% water with stirring.

The fuel opal formed a milky water-in-oil emulsion, and had a viscosity of 1.1 mPa s, which showed no gel-like Schlieren also at -15 ⁰ C.

In the vehicle's carburetor, the idle and main nozzles were replaced by nozzles with an enlarged diameter of approximately 10% and 15%. In normal mixed operation of city traffic and motorway, a consumption of 10.7 - 11.7 1 was determined. This consumption was previously measured with petrol. The driving behavior and the maximum speed corresponded to those previously measured with leaded petrol. The observation of the condition of the candles indicated a clean, residue-free combustion in this mixed traffic. Exhaust gas measurements showed a CO value of 0.5 - 1.0%, while the same vehicle with premium petrol had CO values of 3.5 - 4.5%. During continuous operation, the engine heated up less than measured when driving with prescribed petrol.

example

For better handling of the highly viscous emulsifier mixture from Example 5, the 3% emulsifier with 3% gasoline and 3% water are formed into a clear, low-viscosity solution. This can then be easily dissolved in 64% petrol, possibly using mechanical dosing devices, and immediately emulsified with 22% water. The fuel of Example 5 is obtained in the same composition and quality.

Example 7

• 70,5 % handelsübliches Dieselöl, 2,3 % Stearinsäureamid und 5 Mol Äthylenoxid (gereinigte Ware), 0,7 % Kokosfettsäureamid und 1 Mol Äthylenoxid und 1,5 % Isobutanol werden miteinander gelöst, und sodann werden 25 % Wasser einemulgiert. Es genügt die Anwendung eines einfachen Rührwerkes.

The following fuel was produced for the operation of a diesel engine:

• 70.5% of commercially available diesel oil, 2.3% of stearic acid amide and 5 moles of ethylene oxide (cleaned product), 0.7% of coconut fatty acid amide and 1 mole of ethylene oxide and 1.5% of isobutanol are dissolved together, and then 25% of water are emulsified. The use of a simple agitator is sufficient.

This emulsion can be used directly or can be mixed with 5% methanol if low outside temperatures are expected. A car with a 2-liter diesel engine could be operated without impairment.

The fuel could be obtained in the same quality with the castor fatty acid amide with 1 mol of ethylene oxide, which can be produced in technical quality from 1 mol of castor oil and 2 mol of ethanolamine at 160 - 180 ° C in about 5 hours, if this instead of the coconut fatty acid amide with 1 Mol ÄO was used.

Example 8

The procedure is as in Example 7, but using a diesel oil of the following composition:

This fuel can be used in a diesel powered vehicle without the difficulties of an unstable and stratified fuel.

Example 9

67% regular gasoline was mixed with 1.8% coconut fatty acid amide + 2 moles of AO (made from coconut fatty acids and diethanolamine in a ratio of 1: 1), 1.2% oleic acid amide and 7 moles of AO (purified) and 5% alcohol mixture (84% methanol, 10% Isobutanol, 6% 2-ethylhexanol) mixed and then mixed with 25% water, which was stirred in. With this low-viscosity and stable fuel, the vehicles described in Examples 4, 5 and 6 can be operated in the same way as described there.

The same good results are achieved if 1.5% isopropanol is used instead of the alcohol mixture (increasing the gasoline content to 70.5%).

Example 10 -

A regular gasoline, which is free from lead alkylene and its "fluids", is used with a share of 79%; 1.2% addition product of 1 mol oleic acid amide and 7 mol ethylene oxide (containing less than 0.8% PEG (polyethylene glycol) and less than 0.07% salts by purification) and 1.8% coconut fatty acid diethanolamide are dissolved therein. An opal emulsion is prepared by stirring in a mixture of 15% water and 4% methanol. The density is 0.778. This fuel was run in a 1.7 1 Opel record; the services corresponded to those prescribed for this vehicle. The consumption is the same as for the usual (water and emulsifier free) fuels. After a night out, at which the morning temperature was -19 ° C, the engine could be started easily after a few seconds. A comparative measurement of the exhaust gas value was 1.5% CO for water-free and emulsifier-free gasoline and 0.1% CO for the fuel according to the invention (measured when the engine was warm when the engine was idling). No increase in the N0 ₂ value was measured.

Example 11

The fuel of Example 10 according to the invention was measured in a 3-year-old vehicle for the CO content in the exhaust gas with the engine at operating temperature while idling. The value was 0.3% CO. Regular gasoline gave 3.0% CO. Mixtures of this gasoline with 15% methanol or 15% ethanol led to CO values that deviate less than 0.3% from the value of normal gasoline (details in DE-OS 2 806 673, Figure 2, confirm our measurements for ethanol) .

Example 12

Lead-free regular gasoline was processed into a fuel according to the invention as follows: 80% normal gasoline, 1.2% adduct from 1 mol oleic acid amide + 7 mol AIO, 1.8% coconut fatty acid diethanolamide (made from coconut oil and diethanolamine) were mixed; then 15% water, 2% methanol and 1% ethanol were emulsified in with stirring. This opal fuel brings the top speed in a Mercedes 250 with 95 kW (130 HP) engine power. The main nozzle was adapted to the slightly changed behavior of the fuel by expanding from 97.5 to 105. The consumption was worth, on a reel stand under high load (180 kp), to be equated with premium gasoline. No engine knock was observed despite the normal use of petrol.

The same results were achieved when an oxyalkylated oleic acid amide (prepared from oleic acid, aminopropanolamine by elimination of water and subsequent oxyethylation with 6.5 mol of ethylene oxide) was used instead of the 1.2% of the oleic acid amide with 7 ethylene oxide units.

Example 13

The following diesel fuel was formulated for the operation of a small truck: in 82.5% diesel oil with 0.9% addition product from 1 mol oleic acid amide + 7 mol ÄO, 2.1% coconut fatty acid diethanolamide (made from coconut fat and diethanolamine) and 0.5% 2- Ethylhexanol was emulsified with 14% water. With this fuel, satisfactory driving and consumption values could be achieved in short-haul traffic. Compared to conventional diesel fuel, however, only a barely noticeable contamination was observed within 3 minutes when a partial flow was removed from the exhaust gases over a white filter paper, while the diesel fuel without emulsifiers and water caused the filter to become very black.

Example 14

An aromatic and additive-free gasoline was mixed with 20% toluene. In 85% of this mixture, 1.8% coconut fatty acid diethanolamide and 1.2% oleic acid amide were dissolved with 7 ÅO; 10% water and 2% ethanol were emulsified therein.

This opal fuel emulsion was used in a VW vehicle (̵1.6 liter engine, 62 kw (85 PS)) under DIN consumption conditions 8.4 liters / 100 km. In short-haul traffic, this value was 9.1 1/100 km. The same consumption values were measured with normal gasoline under the same conditions.

If the fuel described in this example was diluted with the mentioned gasoline mixture in a ratio of 1: 1 immediately after production, the same values could be achieved with a trouble-free driving behavior.

Example 15

In 75% of the gasoline mixture of Example 14, 2% of a coconut fatty acid ethanol amide which had been reacted with one mole of ethylene oxide under the usual oxyethylation conditions and 1% oleic acid amide with 7 ÅO were dissolved. A mixture of 10% water and 2% ethanol was emulsified therein. The same values as in Example 14 were achieved with the fuel.

Claims (7)

1. Fuels for internal combustion engines which contain a nonionic emulsifier, water and optionally an alcohol, characterized in that they contain as an emulsifier an adduct of ethylene oxide or propylene oxide with a carboxamide having 9-21 carbon atoms. 2. Fuels according to claim 1, containing 40-95% by weight of hydrocarbons, 0.5-6% by weight of a nonionic emulsifier of the formula

in the R represents an optionally substituted, straight-chain or branched or cyclic, saturated or unsaturated hydrocarbon radical, Y means the grouping, where

R _{2 is} hydrogen or methyl, and in the n stands for an integer from 1 to 50, and R _{1 represents} hydrogen or has the meaning of the grouping (̵Y) ̵ _n H, 0-20% by weight of an alcohol containing 1-8 carbon atoms, which may be straight-chain or branched, saturated or unsaturated, and 0.5-35% by weight water. 3. Fuels according to claim 1 and 2, characterized in that they contain the adduct of 1-3 moles of ethylene oxide with 1 mole of carboxylic acid amide and / or the adduct of 5-25 moles of ethylene oxide and / or propylene oxide with 1 mole of carboxylic acid amide as the nonionic emulsifier. 4. Fuels according to claims 1-3, characterized in that they are the non-ionic emulsifier, the adduct of 1-2 moles of ethylene oxide with 1 mole of fatty acid amide and / or the adduct of 5-10 moles of ethylene oxide and / or propylene oxide with 1 mole of fatty acid amide and optionally contain the adduct of 20 - 30 moles of ethylene oxide with 1 mole of fatty acid amide. 5. Fuels according to claims 1-4, containing as a hydrocarbon component saturated or unsaturated, linear or branched aliphatic hydrocarbons, naphthenic hydrocarbons or aromatic hydrocarbons, which are preferably free of lead tetraalkylene and its solubilizers. 6. Fuels according to claims 1-5, characterized by a volume resistance of <1.10 ¹⁰ Ω. cm. 7. Use of fuels according to claim 1 for gasoline engines, diesel engines, rotary piston machines or turbines.