KR19980701301A - FUEL COMPOSITIONS - Google Patents

Abstract

A fuel oil composition comprising a major proportion of a liquid hydrocarbon middle distillate fuel oil having a sulphur content of not greater than 0.2 % by weight of the fuel oil and a minor proportion of a hydroxy amine which improves the lubricity of the fuel oil. The inclusion of the hydroxy amine in the fuel also markedly reduces the foaming tendency of the fuel oil.

Description

Fuel composition

US A-4,409,000 discloses a fuel additive that is generally liquid, which provides purification power for vaporizers and engines. Mixtures of one or more hydroxy amines and one or more hydrocarbon soluble carboxyl-based dispersants having a particular general formula have been proposed for the purpose of inhibiting sludge formation in vaporizers and engines. The only example relates to the use of such mixtures of components in gasoline as described above. Apart from the fact that the composition provides purifying power of the vaporizer and the engine, no information is provided on the properties provided by such a composition.

US A-2,527,889 discloses polyhydroxy alcohol esters as primary anti-corrosion additives in diesel engine fuels, while UK A-1,505,302 describes ester mixtures including, for example, glycerol monoesters and glycerol diesters as diesel fuel additives. And the mixture is described as inducing benefits such as less wear of the fuel injector, piston ring and cylinder liner.

However, UK A-1,505,302 is concerned with overcoming the operational disadvantages of corrosion and abrasion by acidic combustion products which are residues of combustion chambers and exhaust systems. The document states that this drawback is due to incomplete combustion under certain operating conditions. Typical diesel fuels available at the time of this document contained, for example, 0.5 to 1% by weight sulfur as elemental sulfur, based on the weight of the fuel.

For environmental reasons, namely to reduce sulfur dioxide emissions, the sulfur content of diesel fuels has been reduced in many countries or will be reduced. Thus, the sulfur content of the heating oil and diesel fuel is limited to a maximum of 0.2% by weight by the CEC and the maximum content in the diesel fuel in the second stage is 0.05% by weight. Full conversion up to 0.05% may be required in 1996.

In addition to reducing the sulfur content, methods of making fuels with low sulfur content also reduce the content of other components of the fuel, such as polyaromatic and polar components. Reducing one or more of the sulfur, polyaromatic and polar component contents of the fuel may lead to new problems in the use of the fuel, i.e. reducing the lubrication of the fuel to the injection system of the engine, for example fuel injection of the engine. Pumps can fail relatively early in engine life, where failures occur, for example, in high pressure fuel injection systems such as rotary sprinkler pumps, high pressure rotary sprinklers, inline pumps, unit injectors and injectors. This severe failure is not due to the corrosive wear described in UK A-1,505,302.

As noted above, such failures can occur early in the engine life, whereas the wear problems disclosed in UK A-1,505,302 occur later in engine life. Problems arising from using low sulfur sulfur fuels are described, for example, in D. Wei and H. Spikes, Wear, Vol. 111, No. 2, p. 217, 1986; And R. Caprotti, C. Bovington, W. Fowler and M. Taylor, SAE Paper 922183; SAE fuels and lubes meeting Oct. 1992; San Francisco, USA.

It is now known that the above wear problems resulting from the use of low sulfur fuels can be reduced or met by providing some additives in the fuel. Further advantages also arise using the same additives.

The present invention relates to the use of additives for supplying low sulfur fuel oils with improved lubricity and other advantages and to fuel oil compositions containing the additives.

According to the present invention there is provided a fuel oil composition comprising a large amount of liquid hydrocarbon intermediate distillate fuel oil having a sulfur content of 0.2% by weight or less of the fuel oil and a small amount of one or more hydroxy amines represented by the formula:

Where

R ¹ is an alkenyl radical or alkyl radical having one or more double bonds, having 4 to 50 carbon atoms, or a radical represented by the formula:

[Wherein,

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are independently hydrogen or lower alkyl radicals;

R ⁸ is an alkenyl radical or alkyl radical having one or more double bonds, containing 4 to 50 carbon atoms;

R ⁹ is an alkylene radical containing 2 to 35 carbon atoms, for example 2 to 6 carbon atoms;

p, q and v are integers from 1 to 4;

a, b and c may each be 0, provided that at least one of a, b or c is an integer from 1 to 75.]

A second object of the present invention is the use of a fuel oil composition as defined in the first object of the present invention as a compression ignition (diesel) engine fuel for adjusting the wear rate of an engine injection system during engine operation.

A third object of the present invention is a method of operating a compression ignition (diesel) engine comprising providing a fuel oil composition defined in the first object of the present invention as a fuel of an engine to adjust the wear rate of the engine injection system.

Examples herein demonstrate the wear reduction effects of hydroxy amine additives as defined in the first object of the present invention when using fuel oils having a sulfur content of 0.2% by weight or less.

Without wishing to be bound by theory, in the use of the composition in a compression ignition internal combustion engine, the additives may contain at least a monomolecular or multimolecular layer adhesive on the surface of the injection system, in particular the injection pump moving in contact with one another, over the operating conditions of the engine Partially produced, the composition may have reduced wear, reduced friction, or increased electrical contact resistance in any test where two or more loads are in relative motion under non-hydrodynamic lubrication conditions when compared to compositions that do not contain additives. Will generate one or more of the following:

It has been found that the inclusion of additives in fuel oils greatly reduces the foaming tendency of fuel oils, resulting in the further advantage that the vesicles normally added can be reduced or even eliminated.

The features of the invention are described in more detail below.

additive

As noted above, the additive may be a single hydroxy amine compound or mixtures thereof, and is known to be able to create at least a partial layer on a particular surface of the engine. This means that the layer formed is not necessarily complete on the contact surface. Thus, the formed layer may apply only a portion of the contact surface area, for example at least 10%, or at least 50%. The formation of such layers and the degree of application of the contact surfaces can be demonstrated, for example, by electrical contact resistance or capacitance.

A test embodiment that can be used to demonstrate one or more of reduced wear, reduced friction or increased electrical contact resistance in accordance with the present invention is the High Frequency Reciprocating Rig test described below.

The identified hydroxy amine compounds suitable for use in the present invention may contain R ¹ or R ⁸ groups, which are alkyl or alkenyl groups attached to a nitrogen atom and having one or more double bonds, which groups are 4 to It contains 50 carbon atoms, preferably 8 to 30 carbon atoms, more preferably 12 to 25 carbon atoms. The hydroxy functional group is directly moiety (if a is 1 as described above

Is provided by one or more hydroxy alkyl groups attached to a nitrogen atom indirectly (eg when a is 2 or more) or through an oxyalkylene or polyoxyalkylene linking group. The oxyalkylene unit, which is a hydroxy alkyl group and any linking group, may contain 2 to 6 carbon atoms and may be optionally substituted with lower alkyl radicals. The term lower alkyl refers to alkyl groups containing up to 6 carbon atoms. Preferably, when p, q and v are present they are 1.

The hydroxyalkyl group and any linking group oxyalkylene unit may together form a chain having up to 75 units, including terminal hydroxy alkyl groups. Preferably the number of oxyalkylene units does not exceed 10. The most preferred number represented by a, b, and c in the structural formula is c, where each a, b, and c are present.

The radicals R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are preferably hydrogen or methyl.

When R ⁹ is present in the structural formula, R ⁹ is preferably an alkylene radical containing 2 to 6 carbon atoms and may be straight or branched chain of carbon atoms.

Suitable hydroxy amines can be prepared by reacting an amine substituted with a suitable R ¹ or R ⁸ with the remaining amine functional groups and an alkylene oxide such as ethylene oxide or propylene oxide. Suitable ethoxyamines are sold under the Ethomeen and Ethanolomeen trade names from Amak Company.

The concentration of hydroxy amine effective to significantly improve the lubricity of the fuel is extremely low and can be easily determined by the abrasion test identified in the Examples. Generally, a noticeable reduction in wear is observed using as little additive as on the order of 5 ppm by weight of fuel. Preferred concentrations range from 10 ppm to 0.2% by weight. Higher concentrations may be used, but the wear test should be used to determine the optimal concentration. For economic reasons, the minimum effective amount should be used. Preference is given to concentrations between 25 and 1000 ppm.

A noticeable decrease in the fuel's foaming tendency is observed at lower concentrations of additives, while concentrations as low as 1 ppm can have a significant foaming reduction effect.

Fuel oil

The additives of the present invention are effective when used with liquid hydrocarbon middle distillate fuel oils containing up to 0.2% by weight sulfur.

Preferably, the sulfur concentration is 0.05% by weight or less, for example 0.01% by weight or less, and may be as low as 0.005% by weight or 0.0001% by weight or less. The technique describes methods for reducing the sulfur concentration of hydrocarbon distillate fuel oils, such as solvent extraction, sulfuric acid treatment and hydrodesulfurization.

Intermediate distillate fuel oils to which the present invention can be applied generally boil within a range from about 100 to about 500 ° C, for example from about 150 to about 400 ° C. The fuel oil may comprise an atmospheric distillate or vacuum distillate, or a blend of cracked gas oil or any proportion of distillate that has been directly and thermally and / or catalytically cracked. The most common essential oil distillates are petroleum, injection fuels, diesel fuels, heating oils and heavy fuel oils, and diesel fuels are preferred in the practice of the present invention for the above reasons. The heating oil may be a direct atmospheric distillate or may contain, for example, up to 35% by weight of vacuum gas oil or cracked gas oil or both.

The additive may be incorporated into the bulk fuel oil by methods known in the art. Conveniently, the additive may be incorporated in the form of a concentrate comprising a mixture of additives and a liquid carrier medium that is compatible with the fuel oil, and the additive is dispersed in the liquid medium. This concentrate preferably contains from 3 to 75% by weight, more preferably from 3 to 60% by weight, most preferably from 10 to 50% by weight of additives, preferably in a solution in oil. Examples of carrier liquids include organic solvents including hydrocarbon solvents such as petroleum fractions such as naphtha, petroleum and heater oils; Aromatic hydrocarbons; Paraffinic hydrocarbons such as hexane and pentane; Alkahol; Isoparaffin; And alkoxyalkanols. The carrier liquid should of course be chosen to be compatible with the additive and the fuel.

Auxiliary additives

The additives of the present invention may be used alone or in a mixture of one or more additives. The additive may be one or more additives known in the art, such as detergents, antioxidants (to prevent fuel degradation), corrosion inhibitors, demulsifiers, mist eliminators, metal deactivators, antifoams, cetane improvers, auxiliary solvents, package compounds It can be used in admixture with one or more of the agent and the intermediate distillate deignition improver.

The following examples illustrate the invention. The results are then tabulated using the following materials and procedures.

additive

A. Chemical Formula Hydroxy amine

fuel

I: middle distillate fuel oil having the following characteristics

Sulfur content (% by weight) 0.01

Viscosity at 20 ° C. (cSt) 2.486

Density at 15 ° C. (㎏ / dm ³ ) 0.8136

II: Standard Petroleum Fuels as Commercially Available

III: middle distillate fuel oil having the following characteristics

Sulfur Content (wt%) 0.18

Viscosity at 20 ° C. (cSt) 4.904

Density at 15 ° C. (㎏ / dm ³ ) 0.8462

Example 1

Additive A is dissolved in Fuel I and Fuel II at various concentrations, and the resulting compositions are described in D. Wei and H. Spikes, Wear, Vol. 111, No. 2, p. 217, 1986; R. Caprotti, C. Bovington, W. Fowler and M. Taylor, SAE paper 922183; SAE fuels and lubes meeting Oct. Tested using a high frequency reciprocating machine (HFRR) described in 1992, San Francisco.

This test is known to provide a measure of the lubricity of the fuel.

HFRR test

The results are expressed in terms of wear tread diameters. In addition, friction coefficients were measured. The tests were conducted at different temperatures as specified. The concentration of the additive used is shown in the following table.

Additive A (Concentration ppm, weight / weight) Friction coefficient Wear mark diameter (mm) 20 ℃ 60 ℃ 20 ℃ 60 ℃ Fuel Ⅰ 050100500 0.480.370.240.22 0.550.380.320.22 0.580.520.380.31 0.670.600.580.42 Fuel Ⅱ 050100500 0.340.320.260.24 0.350.320.260.24 0.590.530.350.34 0.770.520.500.45

The results show improved lubricity using additive A.

Example 2

Additive A was added to Fuel Oil III at various concentrations and defoaming performance was measured at 0 ° C. The test used was as follows.

Each sample was stirred vigorously for a period of time to observe the time in seconds at which the bubbles collapsed. The results of untreated fuel and treated fuel are compared in the following table.

Additive A Concentration (ppm, weight / weight) Bubble Collapse Time (sec) (average of 2 scales) Fuel Ⅲ 0550500 83.5403515.5

The test results indicate that in the presence of additive A the foaming tendency of the fuel is significantly reduced.

Claims (10)

A fuel oil composition comprising a large amount of liquid hydrocarbon intermediate distillate fuel oil having a sulfur content of 0.2 wt% or less of the fuel oil and a small amount of one or more hydroxy amines represented by the formula: Where R ¹ is an alkenyl radical or alkyl radical having one or more double bonds, having 4 to 50 carbon atoms, or a radical represented by the formula: [Wherein, R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are independently hydrogen or lower alkyl radicals; R ⁸ is an alkenyl radical or alkyl radical having one or more double bonds, containing 4 to 50 carbon atoms; R ⁹ is an alkylene radical containing 2 to 35 carbon atoms; p, q and v are each an integer from 1 to 4; a, b and c may each be 0, provided that at least one of a, b or c is an integer from 1 to 75. The method of claim 1, A fuel oil composition having a sulfur content of 0.05% by weight or less. The method of claim 2, The fuel oil composition has a sulfur content of 0.01% by weight or less. The method according to any one of claims 1 to 3, A fuel oil composition wherein R ¹ or R ⁸ , if present, contains 8 to 30 carbon atoms. The method according to any one of claims 1 to 4, A fuel oil composition in which a, b and, where present, c do not exceed 10. The method according to any one of claims 1 to 5, A fuel oil composition wherein R ² to R ⁷ are hydrogen or methyl. The method according to any one of claims 1 to 6, A fuel oil composition wherein the concentration of hydroxy amine is 1 to 2000 ppm by weight of the fuel oil. The method according to any one of claims 1 to 7, Hydroxy Amine Formula A fuel oil composition which is a compound of. Use of a fuel oil composition according to any one of claims 1 to 8 as a fuel of a compression ignition engine for adjusting the wear rate in an engine injection system during engine operation. A method of operating a compression ignition engine comprising adjusting the wear rate of an engine injection system by supplying a fuel oil composition according to any one of claims 1 to 8 to the engine fuel.