JP2001526300A - Method for degassing fuel - Google Patents

Abstract

(57) According to the method of the present invention for defoaming fuel, a compound of the formula (I): Is added to the fuel in an effective amount. The R ¹ , R ² and R ³ groups in the formula are, independently of one another, an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms, an aryl or alkylaryl group, or a compound of formula (II): 2] Wherein A ^- is an anion, n is a number of 2 or 3, p is a number of 1 to 3, R ⁴ is 7 to 21 carbon atoms and 0, 1, 2 Alternatively, it is an alkyl or alkenyl group containing three double bonds.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a method for defoaming fuels, more particularly diesel fuel, the use of certain quaternary ammonium compounds as fuel defoamers, and the use of these quaternary ammonium compounds. The present invention relates to a diesel fuel containing an ammonium compound.

BACKGROUND OF THE INVENTION Hydrocarbon mixtures used in fuels, more specifically in diesel fuels,
When filling a storage container such as a fuel tank or a storage tank of an automobile, it has an undesirable property of generating air bubbles together with air. This results in a delay in the filling process and an inadequate filling of the tank. Therefore, in practice, it is common to add a defoamer to the fuel. These defoamers are expected to be effective at low concentrations and have no effect on the fuel combustion process (e.g., by the formation of residues that adversely affect engine performance). Is done.

[0003] Various defoamers for fuels are known from the literature. These are usually silicone-containing compounds, for example as described in EP 773 278 A1. However, such additives can lead to undesired coating of engine filter surfaces or catalysts with silicon dioxide formed during combustion of the fuel.

In addition, recent fuels have been provided with various additives, such as corrosion inhibitors, friction modifiers (used to reduce wear) and engine cleaning additives. However, complicated and expensive tests must be performed to prevent the individual additives from interacting with each other. Accordingly, there is an increasing need for additives with a broad spectrum of action.

[0005] Accordingly, it was an object of the present invention to provide a silicone-free additive for defoaming fuel. Surprisingly, it has been found that certain quaternary ammonium salts have excellent properties as fuel defoamers.

[0006] The present invention is a method for defoaming fuel, comprising the following formula (I):

Embedded image Wherein R ¹ , R ² and R ³ independently of one another are an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms, an aryl or alkylaryl group, or the following formula (II):

Embedded image Wherein A ⁻ is an anion, n is a number of 2 or 3, p is a number of 1 to 3, R ⁴ is 7 to 21 carbon atoms and 0 An alkyl or alkenyl group containing one, two or three double bonds] to the fuel.

DETAILED DESCRIPTION OF THE INVENTION The compounds of the formula (I) are known and are mainly used as fabric softening components or for antistatic finishing of fabrics. Examples of compounds of formula (I) include:
International Patent Application Publication No. WO 94/06899 and German Patent Application Publication No. DE 4203
489A1 (Henkel KGaA), which disclose quaternary diesteramine compounds in fabric softeners. EP 239 910 A2 also describes a textile treatment composition containing quaternary mono- and diesteramine compounds that are readily biodegradable.

[0008] It is known from the applicant's German patent application DE 196 495.85.8 that the compounds of the formula (I) can also have a corrosion inhibiting action. This document describes liquid media,
More specifically, a method for protecting metal surfaces against corrosion in crude oil is disclosed. However, this document contains no mention of the defoaming action of these compounds. It is also not clear from this document that these compounds are suitable as additives for fuels, more specifically for diesel fuels.

[0009] Fuel in the present application is understood to be any energy producing substance whose free combustion energy is converted into mechanical work. These include all types of automotive and aviation fuels that are liquid at room temperature / normal pressure. For example, automotive fuels for automotive and truck engines typically contain hydrocarbons, such as gasoline or relatively high boiling petroleum fractions.

[0010] The method of the present invention is particularly suitable for degassing diesel fuel. Diesel fuel is a substantially non-flammable mixture of liquid hydrocarbons used as fuel for constant pressure combustion or compression ignition engines. The composition of these fuels depends on the manufacturing method and varies. Diesel fuel is obtained from tar obtained in the low temperature carbonization of lignite or anthracite, or from gas oil by cracking. Typical products have a density between 0.83 and 0.88 g / cm ³ , a boiling point between 170 and 360 ° C and a flash point between 70 and 100 ° C.

In the method of the present invention, a compound represented by the formula (I) is added to a fuel in an effective amount. The effective concentration is preferably from 5 to 1000 ppm, more preferably from 10 to 50 ppm, based on the whole fuel. The compound represented by the formula (I) is an effective defoaming agent for fuel and also has a corrosion inhibiting effect.

The compounds of the formula (I) are mono-, di- or tri-fatty acid amine ester compounds which have been industrially quaternized and can be obtained by known synthetic methods (see, for example, European Patent Application See published EP293955A2 and EP293953A2). These quaternary compounds can be, for example, tertiary mono-, di- or trialkanolamines (preferably triethanolamine or triisopropanolamine or methyldiethanolamine or dimethylethanolamine), and saturated or unsaturated linear or It can be obtained by reaction with a branched C _8-22 fatty acid or a derivative thereof (eg, ester or chloride). The ester formed in the reaction with the alkanolamine is then quaternized using, for example, methyl chloride, benzyl chloride or dimethyl sulfate. Suitable fatty acids are, for example, saturated fatty acids, such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid or arachiic acid and mixtures thereof. Suitable unsaturated fatty acids are, for example, linoleic acid, linoleic acid or linolenic acid. Suitable derivatives are, in particular, alkyl esters, preferably methyl esters, of the abovementioned fatty acids. Also suitable are naturally occurring fatty acid mixtures from both animals and plants. Coconut fatty acids and palm kernel fatty acids are particularly preferred.

Preferably, compounds of formula (I) wherein p is 1 and n is 2 are used in the process of the invention. It is particularly preferred to use a compound in which the anion is selected from the group consisting of halide, methosulphate and methosphate in the process according to the invention. The preferred anion is chloride.

The use of mixtures of the abovementioned compounds of the formula (I) in the process according to the invention has proved to be particularly advantageous, since they have been shown to exhibit a particularly good defoaming effect. A group R ¹ and R ² are represented by the formula (II), a compound wherein R ³ of formula (I) is an alkyl group or a benzyl group containing from 1 to 4 carbon atom, R ¹ Contact And R ² is a methyl group and R ³ is a C _1-4 alkyl group or a benzyl group.
A mixture with the compound of formula (1) in a weight ratio of 2: 1 to 1: 2 is preferred. Mixtures of these compounds with a weight ratio of 1: 1 are preferably used in the process according to the invention.

[0015] The present invention also provides a defoaming agent for fuels, more specifically for diesel fuels, having the formula
It relates to the use of the compounds of formula (I). For this purpose, the compounds of the formula (I) can be added to the fuel directly or in the form of a solution or dispersion in a suitable solvent. Particularly suitable solvents are short-chain alcohols containing 1 to 6 carbon atoms, more particularly ethanol, propanol and isopropanol, or aliphatic or aromatic hydrocarbons, such as hexane, heptane or toluene. The solution or dispersion preferably contains the compound of formula (I) in an amount of from 10 to 80% by weight.

The invention further relates to a diesel fuel containing the compound of formula (I) in an amount of from 5 to 1000 ppm. The diesel fuel of the present invention is preferably a low sulfur diesel fuel having a sulfur content of at most 0.2% by weight, preferably at most 0.005% by weight. The diesel fuel may contain other conventional additives such as friction modifiers, flow improvers, wax hardeners or other conventional corrosion inhibitors. However, this diesel fuel preferably does not contain any additional corrosion inhibitors.

Example 1 Preparation of Additive Additive 1 (E1) Caprylic acid methyl ester (279.7 g, 1.75 mol) and triethanolamine (74.5 g, 0.5 mol) were used as a catalyst. Titanium tetrabutyrate (0.5
% By weight, based on the total weight) into a 500 ml stirred reactor. The mixture is then reduced to at least 90% of the theoretically produced methanol (48 g).
Was stirred at 185 ° C. for 10 hours until was distilled off. Excess and unreacted methyl caprylate was distilled off in a thin-layer evaporator at 160 ° C./3×10 ⁻² mbar pressure. The yield contains 2.67% of titratable nitrogen and has a hydroxyl number (OHV
) Was 13 and the amount of the low-viscosity yellow-colored residue was 228.0 g.

The residue obtained (105.1 g, 0.2 mol, based on titratable nitrogen) is 250
dimethyl sulfate (24.2 g, 0.19 mol) in 8 ml of stirred reactor.
It was added dropwise at 5 ° C. The reaction mixture was stirred at 90 ° C. for a further 5 hours and subsequently concentrated. The solid residue was then recrystallized from ethyl acetate. A product containing 0.02% of residual titratable nitrogen was obtained in a yield of 62.8 g.

Additive 2 (E2) Coconut fatty acid methyl ester (444.4 g, 2.0 mol) and dimethylethanolamine (198.0 g, 2.2 mol) were added to titanium tetrabutylate (0.2) as a catalyst. %, Based on the total amount) into a 1000 ml stirred reactor. The reaction mixture was then heated and stirred at reflux. The product was then distilled under a pressure of 10 mbar. The main fraction was a low viscosity liquid containing 4.43% of titratable nitrogen.

For quaternization, 173.6 g (0.55 mol, based on titratable nitrogen) dissolved in isopropanol (60 g) were introduced into the reactor. After heating to 80 ° C., benzyl chloride (66.4 g, 0.52 mol) was added dropwise, followed by stirring at 85 ° C. for 5 hours. The final product of medium viscosity contained 80% of isopropanol and had a residual content of titratable nitrogen of 0.13%.

Defoaming test Diesel (50 ml) was introduced into a 100 ml gas jar and shaken 10 times.
Next, the time required until the generated bubbles were destroyed was measured. The measurement was stopped when the bubble layer collapsed and a bubble-free surface became visible. Additive-free diesel and a defoamer according to the invention in the form of a solution in toluene
The measurement was carried out using diesel added at a concentration of 0 ppm (active substance). The improved defoaming effect was particularly evident when the two additives E1 and E2 were added in a 1: 1 weight ratio according to the invention. The results are shown in Table 1 below.

[0022]

[Table 1]

Corrosion Test The corrosion inhibition properties were tested by a corrosion test according to ASTM D665-92.
For this purpose, steel specimens were immersed for 24 hours at a temperature of 60 ° C. in 330 ml of a diesel oil / water mixture (10 parts by volume of oil for 1 part by volume of water). The specimen was then washed with water and visually inspected for corrosion as compared to the control specimen.
Specimens were evaluated under the NACE scheme. For this purpose, the surface of the test piece showing rust was measured and evaluated according to the following scheme.

[0024]

[Table 2]

The results are shown in Table 3 below. A diesel / water mixture containing a defoamer according to the invention at a concentration of 10 ppm (active substance) was used. The test was performed at three different pHs.
Performed by value.

[0026]

[Table 3]

It will be seen that the defoamer of the present invention also provides good corrosion inhibition results. The favorable results with a mixture of defoamers E1 and E2 are particularly emphasized.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10L 1/22 C10L 1/22 B (72) Inventor Gunter Uphuus Day 40789 Monheim, Robert, Germany Federal Republic of Germany Koch-Strasse 45 (72) Inventor Bernd Butti Federal Republic of Germany Day-40667 Meerbusch, Im Bachgrund No. 5 (72) Inventor Peter Neumann Federal Republic of Germany Day-40589 Dusseldorf, Boschstrasse 30 ( 72) Inventor Frank Bongart, Federal Republic of Germany Day 40670 Meerbusch, Hinsbecker Wech 9th F-term (reference) 4D011 CB01 CB11 4H006 AA02 AA03 AB44 AB68 AD40 BT12 BU50 4H013 CD06

Claims (10)

[Claims] A method for defoaming a fuel, comprising the following formula (I): Wherein R ¹ , R ² and R ³ independently of one another are an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms, an aryl or alkylaryl group, or the following formula (II): 2] Wherein A ⁻ is an anion, n is a number of 2 or 3, p is a number of 1 to 3, R ⁴ is 7 to 21 carbon atoms and 0 An alkyl or alkenyl group containing one, two or three double bonds] to a fuel. 2. The method according to claim 1, wherein the fuel is a diesel fuel. 3. The process according to claim 1, wherein the compound of formula (I) is added to the fuel in an amount of 5 to 1000 ppm, preferably in an amount of 10 to 50 ppm. 4. A compound represented by the formula (I) wherein R ¹ and R ² are a group represented by the formula (II) and R ³ is an alkyl group or a benzyl group containing 1 to 4 carbon atoms. The method according to any of claims 1 to 3, characterized in that it is added to a fuel. 5. Adding a compound of formula (I) wherein R ¹ and R ² are methyl groups and R ³ is an alkyl group or benzyl group containing 1 to 4 carbon atoms to the fuel. The method according to claim 1, wherein: 6. A mixture of compounds of formula (I) according to claim 4 and 5 is added to the fuel in a weight ratio of 1: 2 to 2: 1, preferably 1: 1. The method according to claim 1, wherein 7. The method according to claim 1, wherein a compound represented by the formula (I) wherein the value of n is 2 and the value of p is 1 is added to the fuel. Method. 8. Use of a compound of formula (I) as a defoamer for fuels. 9. The compound represented by the formula (I) according to claim 1,
Diesel fuel contained in ppm amount. 10. The method according to claim 9, which does not contain an additional corrosion inhibitor.
The diesel fuel described in the above.