KR20070037358A - Additive concentrate - Google Patents

Abstract

The present invention relates to an additive concentrate comprising a lubricity improver dissolved in a solvent. Lubricant improvers are 10 to 90 weight percent of the concentrate and are salts formed by the reaction of carboxylic acids with di-n-butylamine or tri-n-butylamine. The concentrate is stable at significantly low temperatures.

Description

Additive Concentrate {ADDITIVE CONCENTRATE}

The present invention relates to additive concentrates and uses for improving the properties of fuel oils, in particular intermediate distillate fuels such as diesel fuels, kerosene and jet fuels.

Attention to the environment has led to the need for reduced sulfur content fuels, in particular diesel fuels, heated base oils and kerosene. However, purification methods that produce fuels of low sulfur content result in lower viscosity and lower content of other components of the fuel (eg, polycyclic aromatics and polar compounds) that contribute to the lubricity of the fuel. . In addition, sulfur-containing compounds are generally considered to provide some anti-wear properties, and the result of a reduction in the proportion of other components that provide lubricity with a decrease in these ratios is a problem reported in fuel pumps in diesel engines. Reduced the number of Problems arise in ware, for example cam plates, plungers, rollers, spindles and drives, which can lead to unexpected pump failures that relatively shorten the life of the engine.

In order to meet the more stringent demands on the exhaust gas, higher pressure fuel systems are generally introduced, including built-in pumps, rotary pumps, common rail pumps and unit injector systems, which are more stringent than conventional devices. It is expected that the problem will worsen in the future, because it is expected to require, and at the same time lower sulfur levels in fuel are more widely required.

Historically, typical sulfur content in diesel fuel has been less than 0.5% by weight. In Europe, maximum sulfur levels have been reduced from 0.20% to 0.05%, and in Sweden, fuel grades of levels below 0.005% (grade 2) and less than 0.001% (grade 1) are used. Fuel oil compositions containing sulfur at levels below 0.05% by weight are referred to herein as fuels with a low sulfur content.

Such low sulfur fuels may contain additives that improve their lubricity. There are several types of additives. In WO 94/17160, a sulfur content comprising an improved lubricity carboxylic acid ester, more particularly an ester in which the acid residue contains 2 to 50 carbon atoms and the alcohol residue contains one or more carbon atoms Start this low fuel. In US Pat. No. 3273981, mixtures of dimeric acids, for example dimers of linoleic acid and partially esterified polyhydric alcohols, are described for the same purpose. In US Pat. No. 3287273, the use of selectively hydrogenated dimer acid glycol esters is described. Other materials used as lubricity improvers or anti-wear agents, and other materials used include sulfided dioleyl norbornene esters (European patent EP-A-99595), beaver oil (US Pat. No. 4375360 and EP-A EP-A). -605857) and methanol-containing fuels, various alcohols and acids having 6 to 30 carbon atoms, acid and alcohol ethoxylates, mono and di-esters, polyol esters and olefin-carboxylic acid copolymers and vinyl alcohol polymers (also US patents) 4375360).

Such additives are mainly provided in the form of additive concentrates, wherein the active species are optionally dissolved in the solvent along with other additives. Although highly effective as a lubricity additive, it has been observed that certain carboxylic acids and carboxylic acid esters as well as other known lubricity additives have the disadvantage of poor solubility at low temperatures. This poor solubility is observed with regard to the solvent used to provide the additive concentrate (mainly hydrocarbon based) and with respect to the fuel to which the additive is added. This places limitations on the storage and use of certain known lubricious additive concentrates at low environmental temperatures.

EP 0 798 364 A1 describes the use of salts formed by the reaction of carboxylic acids and aliphatic amines in particular to improve the lubricity of diesel fuels. The amines used have hydrocarbyl groups and amines, such as oleyl amines (described), having from 2 to 50 carbon atoms, preferably from 8 to 20 carbon atoms. There is no discussion of the low temperature behavior of salts in this document.

US 6,277,158 describes a concentrate containing n-butylamine oleate as a friction modifier for addition to motor gasoline. The inventors point out that despite substantial research on a wide range of friction modifier compounds, n-butylamine oleate is one of only two compounds that provide effects when used with the desired stability and surfactant in the temperature range. Concentrates containing n-butylamine oleate did not indicate the amount of compound present in the concentrate but showed stability at −20 ° C. for extended periods of time.

US Pat. No. US2002 / 0095858 relates to fuel oil compositions containing additives formed by reacting a mono- or dicarboxylic acid having 6 to 50 carbon atoms with an amine having at least one branched alkyl substituent. The additive indicates that it is an effective lubricity improver for the fuel. Data is shown to indicate that the additive itself has good low temperature properties (eg, pour point) and is stable when held at −25 ° C. for 3 days. To demonstrate the advantageous properties of the additives, they are compared with similar species derived from amines which are somewhat more linear than oleic acid neutralized with branched alkyl groups, mainly tri-n-butylamine. The data show that the comparative compound has poorer low temperature properties and crystallizes after 3 days at -25 ° C. There is no data concerning any additive concentrates, ie compounds dissolved in carrier fluids or solvents.

US 2002/0014034 describes the use of additives to improve the lubricity of fuel oils. Suitable additives may be formed by reaction with an acid mixture consisting of N, N-dibutylamine and 70% fat and 30% resin-based acid. The additive shows solubility in diesel fuel in an amount of 5% by weight. Although HFRR data are presented, there is no discussion of the low temperature properties of the additives.

The present invention is based on the discovery of additive concentrates containing certain salts derived from certain aliphatic amines having significantly improved low temperature solubility compared to the almost related salts. Salts are effective lubricant improvers for fuels with low sulfur content. In addition, the salt used in the present invention has the advantage of having a relatively high flash point. This leads to advantages in terms of ease and in the risks associated with their handling and transport.

According to a first aspect, the present invention provides an additive concentrate in which a lubricant improving agent comprising a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine is dissolved in a solvent, wherein the lubricant improving agent is an additive concentrate. 10 to 90% by weight of; When the additive concentrate is retained at −30 ° C., it provides an additive concentrate that remains clear and clear for at least 14 days.

Preferably, the lubricity improver comprises 10 to 80% by weight of the concentrate, more preferably 20 to 80% by weight, for example 33 to 75% by weight, the concentrate is transparent for at least 14 days when kept at -30 ° C. It stays clear.

In a particularly preferred embodiment, the lubricity improver comprises 33-50% by weight of the concentrate and the concentrate remains clear and clear for at least 14 days when retained at -40 ° C.

In a further preferred embodiment, the lubricity improver comprises 33-50% by weight of the concentrate and the concentrate remains clear and clear for at least 28 days when retained at -30 ° C.

In the present invention, the use of the term 'salt' describing a product formed by the reaction of a carboxylic acid with an amine should not be taken to mean that the reaction necessarily forms pure salts. As the salt forms in the reaction, the reaction product contains such salts but because of the completion of the reaction, it is believed that other species will also be present. The term 'salt' should therefore be taken to include pure salt species as well as mixtures of species formed during the reaction of carboxylic acids with amines.

The term 'transparent and clear' as used herein to describe the concentrate will be readily understood by those skilled in the art. Concentrates are essentially particles that are not solid, and are to be taken in the sense that they are completely visible to the naked eye and without any clouding or phase separation.

It was observed that concentrates containing salts formed from di-n-butylamine or tri-n-butylamine exhibit particularly good low temperature properties. This makes it possible to store concentrates containing high amounts of active ingredient under conditions of low temperature environments without costly and complex heat storage. We observe that salts prepared from both shorter-chain linear di-amines such as di-n-ethylamine and longer-chain linear di-amines such as dihexylamine are less effective. I was surprised at this. It was also surprising to note that even the corresponding salts prepared using mono-n-butylamine were significantly less effective.

Easily, either di-n-butylamine or tri-n-butylamine is used, although a mixture of the two may be used if necessary. Most preferably, the salts are anaerobic by reaction with di-n-butylamine.

As the carboxylic acid, a compound corresponding to the formula [R '(COOH) _x ] _y where each R' is independently a hydrocarbon group having 2 to 45 carbon atoms and x is an integer of 1 to 4 is suitable. . Preferably, R 'is a hydrocarbon group having 8 to 24 carbon atoms, more preferably 12 to 20 carbon atoms. Preferably, x is 1 or 2, more preferably x is 1. Preferably y is 1 in which case the acid has a single R 'group. Alternatively, the acid can be a dimer, trimer or more expensive oligomeric acid, in which case y is greater than 1, for example 2, 3 or 4 or more. R 'is an alkyl or alkenyl group which may be suitably linear or branched. Examples of carboxylic acids that can be used in the present invention include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, neodecanoic acid, arachidic acid, behenic acid, lignoseric acid, sertric acid, montanic acid, Contains melisic acid, caprolic acid, oleic acid, ellide acid, linoleic acid, linolenic acid, coconut oil fatty acid, soybean fatty acid, tall oil fatty acid, sunflower oil fatty acid, fish oil fatty acid, rapeseed oil fatty acid, resin oil fatty acid and palm oil fatty acid do. Mixtures of two or more acids in any ratio are also suitable. Anhydrides of carboxylic acids, derivatives thereof and mixtures thereof are also suitable. In a preferred embodiment, the carboxylic acid comprises tall oil fatty acid (TOFA). It was observed that TOFA with a saturation content of less than 5% by weight is particularly suitable. As is known in the art, TOFAs contain small but varying amounts of rosinic acid and its isomers. Preferably, TOFAs having an abiotic acid content of less than 5% by weight, for example less than 2% by weight, are used.

In another preferred embodiment, the carboxylic acid comprises rapeseed oil fatty acid.

In another preferred embodiment, the carboxylic acid comprises soybean fatty acid.

In another preferred embodiment, the carboxylic acid comprises sunflower oil fatty acid.

Aromatic carboxylic acids and their alkyl derivatives as well as aromatic hydroxy acids and their alkyl derivatives are also suitable. Exemplary examples include benzoic acid, salicylic acid and acids derived from these species.

Preferably, the carboxylic acid has an iodine of at least 80g / 100g, preferably at least 100g / 100g, for example at least 130g / 100g or at least 150g / 100g. This was observed to further improve the low temperature solubility of the salts of the present invention.

Thus, a particularly preferred embodiment of the present invention is that the lubricant improving agent is tall oil fatty acid and di-n-butylamine, tall oil fatty acid and tri-n-butylamine, rapeseed oil fatty acid and di-n-butylamine, rapeseed oil fatty acid and Salts formed by the reaction of tri-n-butylamine, soybean fatty acid and di-n-butylamine, soybean fatty acid and tri-n-butylamine, sunflower oil di-n-butylamine and sunflower oil tri-n-butylamine It will include.

Preferably, the flash point of the salt is at least 50 ° C, more preferably at least 60 ° C.

Salts can be readily prepared by mixing carboxylic acids and amines. The order in which one component is added to the other component is not important. The molar ratio of amount of acid to amount of amine is suitably 10: 1 to 1:10, preferably 10: 1 to 1: 2, more preferably 2: 1 to 1: 2, for example about 1: 1 In one embodiment, a molar ratio of 1.1: 1 to 1: 1.1 has been observed to be appropriate. The reaction can be carried out at room temperature, but is preferably heated to, for example, 40 ° C.

Preferably, the solvent is a hydrocarbon solvent, such as an aromatic hydrocarbon solvent. Examples of hydrocarbon solvents include petroleum fractions such as naphtha, kerosene, diesel and heated oils; Aromatic hydrocarbons such as aromatic fractions such as products sold under the trade name SOLVESSO; Alcohols and / or esters; And paraffin hydrocarbons such as hexane, pentane and isoparaffin. The additive concentrate may also contain additional additives as needed. Such additional additives are known in the art and include, for example, surfactants, antioxidants (to avoid fuel degradation), corrosion inhibitors, antifogants, demulsifiers, metal deactivators, antifoams, cetane improvers, co-solvents, packages Compatibilizers, reodorants, additives for improving regeneration of particulate collection, intermediate distillate cold flow improvers and other lubricity additives.

According to a second aspect, the present invention provides a fuel oil composition comprising, in the first aspect, a large amount of fuel oil and a small amount of the additive concentrate according to the first aspect.

Preferably the oil is a fuel oil, for example petroleum fuel oil, in particular intermediate distillate fuel oil. Such distillate fuel oils generally boil in the range of 110 ° C to 500 ° C, for example 150 ° C to 400 ° C. The fuel oil may comprise an atmospheric distillate, a vacuum distillate, a pyrolyzed gas oil, or a blend of any proportion of direct driven and thermally and / or purified steam such as catalytically pyrolyzed and hydrogen-pyrolyzed distillates. The most common petroleum distillate fuels are kerosene, jet fuel, diesel fuel, heater oil and heavy fuel oil. The heated base oil may be a direct atmospheric distillate or may contain small amounts, for example up to 35% by weight of vacuum gas oil, pyrolyzed gas oil or both.

Other examples of fuel oils include Fischer-Tropsch fuels. Fischer-Tropsch fuels, also known as FT fuels, include fuels described as liquid (GTL) fuel in gas, liquid (BTL) fuel in biomass and coal conversion fuel. To produce this fuel, syngas (CO + H ₂ ) is first generated and then converted to normal paraffins by a Fischer-Tropsch process. The normal paraffins are then modified by methods such as catalytic pyrolysis / purification or isomerization, hydropyrolysis and hydroisomerization to yield various hydrocarbons such as iso-paraffins, cyclo-paraffins and aromatic compounds. The resulting FT fuel can be used as such or in combination with other fuel components and fuel types such as the fuels mentioned herein. Also suitable are fuels derived from plant or animal sources such as FAME. These may be used alone or in combination with other types of fuel.

Preferably, the fuel oil has a sulfur content of 0.05% by weight or less, more preferably 0.035% by weight or less, in particular 0.015% by weight or less. Fuels with much lower sulfur content are also suitable, for example, less than 50 ppm by weight sulfur, preferably less than 20 ppm by weight, for example up to 10 ppm.

Preferably, the amount of salt in the additive concentrate used is at a level of 5 to 1000 ppm by weight, more preferably 10 to 500 ppm, even more preferably 10 to 250 ppm, in particular 10 to 150 ppm, for example 50 to 150 ppm, in the fuel oil. exist.

According to a third aspect, the present invention provides the use of an additive concentrate according to the first aspect for improving the lubricity of fuel oils having a sulfur content of less than 0.05% by weight.

According to a fourth aspect, the present invention includes a lubricant improving agent comprising dissolving 10 to 90% by weight of a salt formed by reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine in a hydrocarbon solvent. The additive concentrate is stored at -30 ° C to provide a method for maintaining a clear and clear for at least 14 days.

The additives of the present invention may contain a salt alone or a mixture of one or more salts.

In the following, the present invention is described by way of examples.

Example

Example 1

Tall oil fatty acid (TOFA-1) (50.0 g, 173 mmoles) having a saturation content of about 2% and a rosinic acid content of about 1.8% was added to the beaker with stirring. Then di-n-butylamine (22.36 g, 173 mmole) was added to the beaker. An exotherm of about 38.3 ° C. with two components reacting was measured. The ammonium species FTIR analysis of the reaction product is compared with the disclosed acid represents a strong carboxylic acid peak decreases at 1710cm ^-1, as well as the appearance at 1553 and 1399cm ^-1 corresponding to the carboxylate asymmetric and symmetric stretching at 2300 to 2600cm ^-1 The appearance of a corresponding broad range of peaks was seen. This clearly indicated the formation of salts. The flash point of the reaction product was 67 ° C.

Example 2

Example 1 was repeated using tri-n-butylamine at the position of di-n-butylamine. Tall oil fatty acid (TOFA-1) (30.0 g, 94.5 mmol) having about 2% saturated content and about 1.8% rosin acid content was added to the beaker with stirring. Tri-n-butylamine (17.52 g, 94.5 mmol) was then added to the beaker. An exotherm at about 13 ° C. was measured in which the two components reacted. The ammonium species FTIR analysis of the reaction product is compared with the disclosed acid represents a strong carboxylic acid peak decreases at 1710cm ^-1, as well as the appearance corresponding to the carboxylate asymmetric and symmetric stretching at 1571 and 1371cm ^-1 at 2300 to 2600cm ^-1 The appearance of a corresponding broad range of peaks was seen. This clearly indicated the formation of salts. The flash point of the reaction product was 90 ° C.

Example 3

Example 1 was repeated with tall oil fatty acid (TOFA-2) having a saturation content of about 2% and a rosinic acid content of about 0.8%.

Example 4

Example 2 was repeated with tall oil fatty acid (TOFA-2) having a saturation content of about 2% and a rosinic acid content of about 0.8%.

Example 5

Rapeseed oil fatty acid (33.87 g) was added to the solvent (Atasol 150, 50 g) at about 30 ° C. and stirred until well mixed. Di-n-butylamine (16.13 g) was then charged to the mixture. The exotherm in which the two components showed a reaction was measured. After the exotherm was reduced, stirring was maintained for an additional 4 hours. The product was pumped below the flash point of the solvent.

Example 6 (comparative example)

Example 1 was repeated using di-n-ethylamine instead of di-n-butylamine. The flash point of the obtained product was 42 ° C.

Example 7 (comparative example)

Example 3 was repeated using di-n-ethylamine instead of di-n-butylamine. The flash point of the obtained product was 42 ° C.

Example 8 (comparative example)

Example 1 was repeated using di-n-hexylamine instead of di-n-butylamine. The flash point of the obtained product was 122 ° C.

Example 9 (comparative example)

Example 3 was repeated using di-n-hexylamine instead of di-n-butylamine. The flash point of the obtained product was 122 ° C.

Stability test

Additive concentrates of the salts of Examples 1-4 were filled as 33, 50 and 75% by weight solutions in Solvesso 100 and tested for low temperature stability at -30 ° C and -40 ° C with similar solutions of Comparative Examples 5-8. The results are shown in Table 1 below. In the table, the data refers to the number of days the test sample remains clear and clear. All tests are run for a maximum of 28 days, and the results of '28' in the table do not necessarily indicate a decline at 28 days. From the results obtained, the concentrates according to the invention showed improved stability at high concentrations and low temperatures as compared to the examples containing salts produced in linear amines of longer or shorter chain lengths.

Example 10 (comparative example)

As a further comparison, salts were prepared by reacting n-butylamine with TOFA-1 and TOFA-2 following the same procedure as in Examples 1 and 3. Concentrates containing 50% by weight in Solvesso 100 showed only very limited stability at -40 ° C (3 days for TOFA-1 salt). Concentrates containing 75% by weight in Solvesso 100 showed no stability at -40 ° C.

HFRR test

The salts prepared in Examples 1 to 4 above were described in detail in Table 2 in terms of two low sulfur diesel fuels using High Frequency Reciprocating Rig (HFRR) according to BS EN ISO 12156-1 (2000). Presented). The results are shown in Table 3. The HFRR value for untreated fuel 1 was 664 μm and 518 μm for untreated fuel 2.

It is evident from the results presented in Table 3 that the additive concentrate of the present invention is an effective lubricity improver for diesel fuels with low sulfur content.

The salts produced in Example 5 were tested in many diesel fuels. The material was used as a 50 wt% solution in Solvesso 150 and added to diesel fuel at a processing rate of 100 wppm (calculated based on active ingredient content). HFRR test results are shown in Table 4 below. Each value in the table was the average of many tests. For example, the names of fuels using Korean ULSD 1 and Korean ULSD 2 indicate that two different fuels of the same general type are used.

Good improvement in lubricity was observed for all fuels. In addition, a 50% by weight solution of the salt of Example 5 in Solvesso 150 was tested for low temperature stability. Samples remained clear and clear when retained for 28 days at -30 ° C.

The present invention provides an additive concentrate comprising salts with improved flash point and high flash point as an effective lubricity improver, particularly for fuels with low sulfur content.

Claims (10)

An additive concentrate comprising a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine, is an additive concentrate dissolved in a solvent, wherein the lubricant improver is included in 10 to 90% by weight of the additive concentrate. , An additive concentrate that is maintained clear and clear for at least 14 days when the additive concentrate is held at -30 ° C. The method of claim 1, An additive concentrate wherein the lubricity improver is comprised between 33 and 50% of the additive concentrate and which remains clear and clear for at least 14 days when the additive concentrate is held at -40 ° C. The method of claim 1, An additive concentrate wherein the lubricity improver comprises 33-50% of the additive concentrate and which remains clear and clear for at least 28 days when the additive concentrate is held at -30 ° C. The method according to any one of claims 1 to 3, An additive concentrate wherein the carboxylic acid comprises a fatty acid or fatty acid mixture. The method according to any one of claims 1 to 4, An additive concentrate in which the carboxylic acid comprises tall oil fatty acid or rapeseed oil fatty acid. The method according to any one of claims 1 to 5, An additive concentrate wherein the solvent is a hydrocarbon solvent, such as an aromatic hydrocarbon solvent. A fuel composition comprising a large amount of fuel oil and a small amount of the additive concentrate according to any one of claims 1 to 6. The method of claim 7, wherein A fuel composition comprising a middle distillate fuel oil having a sulfur content of 0.05% by weight or less. Use of the additive concentrate according to any one of claims 1 to 6 for improving the lubricity of fuel oils having a sulfur content of 0.05% by weight or less. Storing an additive concentrate containing a lubricity improver at −30 ° C. comprising dissolving from 10 to 90% by weight of the salt formed by the reaction of the carboxylic acid with di-n-butylamine or tri-n-butylamine in a hydrocarbon solvent. To remain transparent and clear for more than 14 days.