NO141519B - PETROL-BASED FUEL AND ADDITIVES FOR USE THEREOF - Google Patents

Description

The present invention relates to an improved gasoline-based fuel for internal combustion engines as well as a two-component additive combination for use in this fuel. In particular, the invention relates to the discovery that the addition of an additive combination or mixture to petrol results in less coating formation in the upper part of the petrol/air intake, including the area around the carburettor mixture cylinder, than is found in petrol mixtures containing a single additive from the above combination.

Modern internal combustion engines undergo significant changes in order to meet certain requirements regarding exhaust emissions. A main change in the engine construction which is currently being widely used is to direct blow-through gases that have entered the crankcase out of the engine by redirection to the air intake in front of the carburettor instead of releasing the blow-through gases to the atmosphere as before. These pass-through gases contain significant amounts of coating-depositing substances and it has been found that some of these substances form coatings in and around the damper area in the carburettor. The deposits prevent air flow through the carburettor and the idle nozzle at low speed so that you get an over-rich mixture. The condition- gives rise to uneven idling, engine stalling and emission of unburnt hydrocarbons in the exhaust gases.

In addition to remedying the above problem, the addition of the present additives will provide a corrosion inhibition and anti-icing effect.

The use of amine derivatives such as amides, imides, amines, imidazolines, triazines, pyrimidines, polyamides, low molecular weight polymers, organophosphates and amine phosphates and common ammonium salts of such compounds are well-known fuel additives that partially increase the carburettor system's effect. Examples of U.S. patents describing the use of alkyl substituted diaminoamide derivatives are U.S. Patent Nos. 2,805,135, 2,922,707, 2,996,365, 3,251,853, 3,313,607, 3-589,877, 3,653,853, 3,704,109, 3,707,361 and 3,813,228.

The deposits that are deposited in the carburettor system can partly be due to the own components of the petrol used, but it is assumed that the deposits are to a greater extent due to foreign substances that enter the carburettor through the air intake since the air filters are never completely effective. The main causes of air pollution are vapors and gases from the crankcase, exhaust gases, stbv, rbyk and the like. The problem with respect to carburettor deposits from air pollution becomes even greater with the crankcase ventilation system back to the carburettor, as mentioned above, in many of the newer engine types. In engines equipped with positive crankcase ventilation (recirculation of blow-by gases from the crankcase back to the carburettor), dust and gases from the crankcase are fed through a metering valve into the engine's air intake system. Although this system helps to reduce soot emissions into the atmosphere, it will, on the other hand, increase the problem of deposits in the carburettor. Such coatings are not only found in the carburettor, but also in the parts in the metering valve which are used in connection with the aforementioned postive crankcase ventilation.

Another source of deposits in the carburettor is the fuel's own composition and history. Trace impurities in the fuel resulting from the manufacturing processes, storage and geographical origin are believed to be responsible for the lacquer and rubber coatings of high molecular composition that are deposited after long-term use.

Many marketed gasolines and fuels contain additives that are used to either keep the intake system free of further deposits ("self-cleaning") and/or to remove already deposited deposits ("cleaning"), and then keep the system clean. The latter cleaning effect requires much higher dosages of additives than for a self-cleaning effect.

The present invention provides a gasoline-based fuel containing a minor amount of additive combination which acts as a cleaning agent by keeping the intake system in an internal combustion engine free of further deposits or cleans up already deposited deposits and then keeps the system relatively clean.

According to the present invention, a petrol-based fuel is provided and this fuel is characterized by the fact that it contains 0.003 - 0.15% by weight of a two-component additive combination consisting of at least one compound of general formula A:

and at least one compound of general formula B: where R denotes an aliphatic hydrocarbon residue with 10-20 C atoms, R' denotes an aliphatic hydrocarbon residue with 9-19 C atoms, and R" denotes an aliphatic hydrocarbon residue with 10-15 C- atoms, the weight ratio between component A and component B being in the range 1:9 to 9:1. It is preferred that component A is N-"tallow"-propylenediaminomonooleate and that component B is N-(3-tridecyloxypropyl)propylenediaminomonooleate .

Furthermore, according to the invention, a two-component additive combination is provided for use in the above-mentioned fuel, and this additive combination is characterized by the fact that it consists of a reaction product from the reaction of a monocarboxylic acid with 10 - 20 C atoms with a mixture of an N-alkyl-substituted propylenediamine derivative where the alkyl substituent is an aliphatic group with 10 - 20 C atoms and an N-(3-tridecyloxypropyl)propylenediamine, so that the molar ratio between the monocarboxylic acid in the reaction mixture and each of the propylene-diamine derivatives is 2:1.

The first above-mentioned component with a purifying effect is thus produced by reacting a monoalkyl-N-substituted propylenediamine derivative with monocarboxylic acids to produce the N,N'-amide derivative. Particular examples of such N-aliphatic-substituted propylenediamines are N-nonyl-propylenediamine, N-tetradecylpropylenediamine, N-tetradecenpropylenediamine, N-hexadecylpropylenediamine, N-eicosylpropylenediamine, N-eicosenylpropylenediamine, N-docosylpropylenediamine, and N-docosenylpropylenediamine. The compounds where the aliphatic N-substituent is an alkyl or alkenyl group containing at least 12 and preferably 16 - 20 C atoms seem to be particularly effective. Examples of N-aliphatic-substituted propylenediamines that seem to form particularly effective compounds are N-dodecyl- and N-hexadecyl-propylenediamines and especially 18 C alkyl-, alkenyl- and alkadienyl-substituted propylenediamines such as N-octadecyl-, N-octadecenyl- and N-octadecadienylpropylenediamine. Mixtures of N-aliphatic-substituted propylene diamines which are formed when the aliphatic N-substituent is derived from mixed fatty acids from natural fats and oils form very effective compounds for use in compositions according to the invention. In such cases, the aliphatic N-substituent is a straight-chain, monovalent hydrocarbon radical with from 10 - 20 C atoms. Examples of such mixtures of N-aliphatic-substituted propylenediamines are N-"tallow" ("cattle fat")-propylenediamine, N-"soybean oil"-propylenediamine and N-"coconut oil"-propylenediamine where the respective N-substituents are mixed alkyl- and cross-linked alkyl groups derived from animal Halg fatty acids (C-^-C-^g), soybean oleic fatty acids (C-^g-C20): and coconut fatty acids (Cg-C18).

These N-aliphatic-substituted propylene diamines can be prepared by converting commercial fatty acids to their corresponding nitriles and then reducing the nitriles with hydrogen to the primary amine. This primary amine is then treated

with acrylonitrile to produce the corresponding cyanopropyl(aliphatic)amine which is then hydrogenated to alkyl substituted propylenediamine. Examples of marketed N-aliphatic-substituted propylene diamines are "Duomeen-T" and "Duomeen-S" which have general formulas RNHC^CI^CtL-jNf^, where R is derived from "tallow" fatty acids and soy fatty acid, respectively .

The monocarboxylic acid amine in the alkyl-substituted diamine is prepared by mixing the acid with the diamine in equimolar amounts. Particular examples of preferred acids are 2-ethylhexanoic acid, oleic acid, stearic acid, capric acid, decylenic acid, undecylenic acid, lauric acid, myristic acid, palmitic acid, ricinoleic acid, linoleic acid, arachidic oleic acid, behenic acid oil, erucic acid oil, octacosinic acid oil and mixtures of these prepared from coconut oil, tallow oil and soybean oil.

Particular examples of these amide derivatives are: N-hexadecylpropylenediamine monooleate, N-octadecylpropylenediamine monooleate, N-octadecylpropylenediamine stearate, N-tallow propylenediamine monooleate, N-soybean oil propylenediamine monooleate and N-coconut oil propylenediamine stearate.

A preferred cleaning agent derivative from the above class is prepared by reacting 1 mol of oleic acid marketed under the trademark "Acintol F.A. No. 1" with 1 mol of N-"tallow oil"-propylenediamine marketed under the trademark "Kema-mine D-974" at a temperature between 50 and 105°C until 1 mole of water has been removed.

The second cleaning agent component in the mixture is produced by reacting compounds with the general formula:

where R" denotes an aliphatic hydrocarbon residue with 10 - 15 C atoms, with a monocarboxylic acid with 10 - 20 C atoms, selected from those previously described. Such starting materials are commercially available and can be reacted at temperatures up to about 105°C in equimolar amounts during the elimination of 1 mole of water.

A preferred compound is prepared by reacting 1 mole of oleic acid ("Acintol F.A. No. 1") with N-tridecyloxypropylethylendiamine ("Adogen 583").

The additive combination with cleaning action according to the invention can also be prepared by simultaneously reacting, in a container, equimolar amounts of N-alkyl-substituted propylenediamine and N-alkoxypropyl-propylenediamine derivatives with 2 equivalents of monocarboxylic acid to form a mixture of cleaning compounds. In the production of such combined cleaning mixtures, as mentioned, the A and B diamine derivatives are present in the final combination in a weight ratio of 1:9 to 9:1. Naturally, the separately produced cleaning agents can be mixed in the above weight ratio and then the petrol added, so that the total content of cleaning agent is 0.003 - 0.15% by weight of the petrol. Naturally, each individual cleaning agent can also be added directly to the petrol in suitable weight ratios and concentrations.

The advantages which can be obtained by using the invention can be understood more clearly in connection with the following examples which show the improved results obtained by adding the second cleaning component to the first. It was unexpectedly found that the combination of said cleaning agents gave superior results in relation to the use of only one or only the other additive in the same gasolines and under the same conditions.

Example 1

In a test apparatus with the designation ISD (Induction System Deposit = system for developed coatings) in the form of a bench apparatus, the performance of the cleaning mixtures in question in a petrol intended especially for oil engine forsbk was measured. This bench facility was designed specifically for military and commercial organizations and is described in detail in a publication entitled "A Bench Technique for Evaluating the Induction System Deposit Tendencies of Motor Gasolines" by A.A. Johnston and E. Dimitroff, SAE Transactions, Volume 75 (1967')., Publication No. 660783. In the experiment, a stream of fuel is placed in a stream of air on a preweighed and heated coating-collecting aluminum tube. When the gasoline hits the heated rudder, a flash vaporization occurs from a thin film of gasoline, leaving varying amounts of coating depending on the fuel's deposition tendencies.

In order to demonstrate the synergistic effect of one component in addition to the other, with regard to increasing their individual effects as antifouling cleaners, different concentrations of N-"tallow oil" propylene diamine monooleate, designated component A, and N- (3-tridecyl-oxypropyl)-propylenediamine monooleate with the designation component B, in the above bench sample, when added to petrol with analytical values as described in table I.

In table II are the results of the bench trial and it can be seen that the cleaning agent combination causes a significantly lower deposition rate or less amount of coating than each additive used separately.

Example 2

The effect of the additive mixture is demonstrated more realistically by comparing its effect as a cleaning agent with regard to keeping valves and carburetors clean in a standard V-8 car engine with minor modifications so that two gasolines can be compared simultaneously. Removable aluminum sleeves were placed in the throttle openings in two research carburettors and the coating weight for the deposit collected on these sleeves is a measure of the additive's effect. The result of a 24-hour test is shown in table III with unleaded petrol as fuel, of the type described in example 1. The results shown in table III show that additive A is improved by a factor of approx. 10 percent, while additive B is improved by a factor of approx. 20 percent.

Claims (3)

1. Gasoline-based fuel, characterized in that it contains 0.003 - 0.15% by weight of a two-component additive combination consisting of at least one compound of general formula A: and at least one compound of general formula B: where R denotes an aliphatic hydrocarbon residue with 10-20 C atoms, R' denotes an aliphatic hydrocarbon residue with 9-19 C atoms, and R" denotes an aliphatic hydrocarbon residue with 10-15 C atoms, the weight ratio between component A and component B is in the range 1:9 to 9:1. 2. Fuel according to claim 1, characterized in that component A is N-"tallow" propylenediaminomonooleate and component B is N-(3-tridecyloxypropyl)propylenediaminomonooleate. 3. Two-component additive combination for use in the fuel according to claim 1, characterized in that it consists of a reaction product from the reaction of a monocarboxylic acid with 10 - 20 C atoms with a mixture of an N-alkyl substituted propylene diamine derivative where the alkyl substituent is an aliphatic group with 10 - 20 C atoms and an N-(3-tride-cyloxypropyl)propylenediamine, so that the molar ratio between the monocarboxylic acid in the reaction mixture for each of the propylene-diamine derivatives is 2:1.