FUEL COMPOUND FOR INTERNAL COMBUSTION ENGINES

Abstract

 The invention concerns a fuel compound for use in hydrocarbon-fuel based internal combustion engines with spark ignition. The compound contains an anti-knock additive in the form of industrial ferrocene, specifically 0.001-0.2 wt.% α-hydroxyisopropyl/ferrocene.

Description

[0001] The present invention relates to lead compound free high-octane fuel compositions for internal combustion engines with spark ignition, prepared by using hydrocarbon fuels and anti-knock additive.

[0002] There are known fuel compositions (1) based on hydrocarbon fuels containing ferrocene derivatives as anti-knock additive such as m-nitrocinnamoyl ferrocene


   and o-chlorocinnamoyl ferrocene


   A considerable obstacle for using ferrocene and its derivatives as an anti-knock additive to the engine fuels is that in the combustion chamber, more specifically on sparking plugs some deposits of iron oxides are formed, causing some failures in the operation of an engine (2).

[0003] In addition said m-nitrocinnamoylferrocene and o-chlorocinnamoylferocene are produced from ferrocene in a number of stages with a low yield and all characterized with a low solubility rate in the fuel composition.

[0004] It is an object of the present invention to create a high octane fuel composition for internal combustion engines eliminating said drawbacks.

[0005] This object is attained by using as anti-knock additive /a-hydroxyisopropyl/ferrocene

[0006] As hydrocarbon fuel is used a basic hydrocarbon composition based on a stable catalysate, the ingredients of which are as follows:

aromatic hydrocarbons	54 to 56 percent
normal alkanes	12 to 13 percent
isoalkanes	29 to 31 percent
naphthenes	1 to 2 percent

having fractions as follows:

initial boiling point	60 grad.C
distillation fraction of 10 percent	83 grad.C
distillation fraction of 50 percent	114 grad.C
distillation fraction of 90 percent	156 grad.C
distillation fraction of 96 percent	190 grad.C

density p20/4 being 0.7687 g/cm3 and motor octane number being 80.

[0007] The present invention is explained with examples recited in the table as follows.

[0008] The fuel composition octane number was determined on the plant UIT-85 by a motor method according to CMEA Standard 2243-80. The plug operation-to-failure time was determined on the singie cylinder compartment of the engine ZIL-130 at alternative modes covering a wide spectrum of changed parameters such as temperature of cooling liquid, load, ingredients of mixture and lead angle of ignition. The test was carried out by some five-hour cycles.

[0009] Iron oxide on the sparking plug A11 with an initial gap being 0.64 mm was appreciated by parameters as follows: change of sparking gap, change of the sparking plug weight, iron oxide deposit surface nature on the sparking plud electrodes. The sparking gap was measured by using the projector type SVET with magnification X100 and iron oxide deposit surface nature was estimated by means of optical microscope type MIN-8 with magnification X50.

[0010] The fuel composition was tested by using as anti knock additive a ferrocene derivative corresponding to prior art and a ferrocene derivative in different amounts according to the present invention (Examples 7 to 10).

[0011] The analysis of data recited in the Table above allows to see that the iron oxide deposits formed at the combustion of the fuel composition according to the invention and prior art fuel compositions have different nature and their accumulation on the sparking plug proceeds at different rates. Thus, the known prior art fuel used to produce some dense solid varnished iron oxide deposits. However at the combustion of the fuel composition according to the present invention some crumbly microporous deposits.

[0012] Thus, Examples 7 to 10 (fuel composition according to the invention) allow to see that the accumulation of iron oxide deposit up to the equal weight state (50 to 55 mg) proceeds for 25 hours and remains at this level for a long period of the tests. At the same time the known prior art fuel composition containing an equivalent amount of iron (458 x 10⁻⁵ percent) in the fuel mixture when the similar amount of iron oxide deposit (50 to 55 mg) for a more extended period of time (35 to 40 hours) leads to a stoppage of the engine (see Examples 1,4).

[0013] However a step of decreasing the content of anti-knock ferrocene additives by iron to 229 x 10⁻⁵ percent as for the fuel composition according to the invention allows to increase the time to achieve the equal weight state of iron oxide deposit up to a level of 40 hours and to diminish the deposit value in the equal weight state down to 30 to 34 mg (see Example 9).

[0014] At the same time in a case of the known prior art fuel composition a similar amount of iron oxide deposit (30 to 34 mg) is accumulated for 50 to 55 hours and for the next 5 to 10 hours the further increase of the iron oxide deposit occurs up to 36 to 38 mg. This feature shows that in the operation of the engine the iron oxide deposits will be accumulated permanently.

[0015] Thus, the use of α-hydroxyisopropyl ferrocene as anti-knock additive allows to increase the life of the sparking plugs without worsening the performances of the engine.

[0016] In addition, the use of α-hydroxyisopropyl ferrocene in the fuel composition allows by 15 to 20 percent to increase the growth of octane number as compared to m-nitrocinnamoylferrocene and o-chlorocinnamoyl ferrocene at the equivalent content of iron (see Examples 7 to 10 and 1 to 9).

[0017] The use of α-hydroxyisopropyl ferrocene allows to increase by two times the content of iron as compared to the prior art fuel compositions containing m-nitrocinnamoylferrocene without inflicting any damage to the operation of sparking plug of the engine, increasing the octane number by 1.1 to 1.2 units (see Example 8).

[0018] In addition the use of α-hydroxyisopropyl ferrocene allows to reduce the toxicity rate of combustion products.

[0019] The lower limit of the use of α-hydroxyisopropyl ferrocene is 0.001 percent (see Example 10),the upper limit is 0.02 percent (see Example 8) and corresponds to the maximum possible content at which a faultless operation of the engine is provided.

[0020] The industrial applicability of the fuel composition according to the invention is ensured by using a simple technological implementation for the production thereof.

Claims

1. A fuel composition for spark ignition internal combustion engines, prepared by using hydrocarbon fuel, comprising an anti-knock additive in the form of ferrocene derivatives, characterized in that said composition as additive contains /a-hydroxy isopropyl/ferrocene in an amount of 0.001 to 0.02 wt.percent.
(56)

1.

. Toma, P.Ele

ko, V.Vesely, M.Sali

ova Derivaty ferocenu ako prisady do benzinov. Acta facultatis rerum naturalium universitatis comenianae-formatio et protectio naturae 1981 No. 7, 187-192 (Ref Journal CHEMISTRY, 12, II 224 (1982)

2. E.G.Perevalova, M.D.Reshetova, K.I.Granberg, "Methods of Elementorganic Chemistry", Moscow, Publishing House NAUKA, 1983, p. 439 (Russian edition).