EP0780460B1

EP0780460B1 - Gasoline additive concentrate

Info

Publication number: EP0780460B1
Application number: EP96309357A
Authority: EP
Inventors: Alan M. Schilowitz
Original assignee: ExxonMobil Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1995-12-22
Filing date: 1996-12-20
Publication date: 2001-06-27
Anticipated expiration: 2016-12-20
Also published as: NO970968D0; ATE202595T1; EP0780460A1; DE69613549T2; NO315126B1; DE69613549D1; NO970968L

Abstract

The present invention is a gasoline additive concentrate which remains liquid at low temperatures of about 0 DEG F which contains a fatty acid, ester or mixtures thereof in combination with an alcohol, an amine or a mixture thereof.

Description

The present invention relates to a gasoline additive concentrate containing solubilizers to maintain the concentrate in the liquid state at low temperatures.
U.S. Patent 4,617,026 is directed to a method for reducing the fuel consumption in an automotive internal combustion engine by employing a gasoline fuel containing an effective fuel consumption reducing amount of an additive which is a hydroxyl-containing ester of a monocarboxylic acid and a glycol or trihydric alcohol, said ester additive having at least one free hydroxyl group.
U.S. Patent 5,279,626 is directed to a fuel additive concentrate having an enhanced shelf life, the concentrate comprising a major amount of detergent/dispersant, a minor amount of demulsifier and an amount of solvent stabilizer sufficient to enhance the shelf life of the fuel additive package. The solvent stabilizer is formed from at least one aromatic hydrocarbon solvent and at least one alkyl or cyclic alkyl alcohol wherein the solvent stabilizer composition contains more than 50 wt% aromatic hydrocarbon solvent and 10 to less than 50 wt% alcohol. The demulsifiers include organic sulfonates, polyoxyalkylene glycols, oxyalkylated phenolic resins and the like. Other components can be present in the concentrate including anti-oxidants, corrosion inhibitors, emission control additives, lubricity additives, antifoamants, biocides, dyes, octane or cetane improvers and the like. Corrosion inhibitors include dimers and trimer acids such as those produced from tall oil fatty acids, oleic acid, linoleic acid, and the like.
European Patent Publication EP 482 253 A discloses a middle distillate fuel with reduced emissions. The fuel contains an ashless dispersant such as an alkenyl succinimide of an amine. It may also contain a hindered phenol antioxidant, and one or more other conventional fuel additives including demulsifying agents, metal deactivators, antifoam agents, corrosion inhibitors, lubricity additives, friction modifiers and solvents.
US Patent 4 565 547 describes a fuel composition containing a detergent system to remove deposits. The detergent system comprises a C₁₈ fatty acid, an ammonia/amine mixture, and an ester of a higher fatty acid. The amine is either a C₁ - C₁₀ alkylamine, a C₂ - C₁₀ alkanolamine or morpholine. The fuel may also contain a solubilising auxiliary solvent such as an aliphatic alcohol.
UK Patent Publication 1 074 232 A describes a jet fuel containing as lubricity additive the reaction product or a mixture of a hydroxy amine or polyamine with a dialkyl ester of a dicarboxylic fatty acid.
WO Patent Publication 95/02654 describes a diesel fuel containing a significant proportion of alcohol. To assist the solubility of the alcohol in the fuel a fatty acid and/or an organic ester is added.
UK Patent Publication 2 269 824 describes a middle distillate fuel containing, as a wax anti-settling additive, the reaction product of a C₁₂ - C₂₂ fatty amine with a C₁₆ - C₂₄ carboxylic acid. The additive is contained in a solvent mixture of non-polar and weakly polar solvents. The additive also acts to prevent the formation of an emulsion of the distillate fuel and water.
US Patent 4 797 134 describes a gasoline with improved combustion and hence reduced emissions, containing an additive composition comprising (a) an organic peroxide, (b) a detergent, for example a mixture of an amine and a carboxylic acid, and (c) a suitable hydrocarbon solvent such as fuel oil.
US Patent 4 451 265 describes a hybrid fuel which is a microemulsion of diesel fuel and water. The fuel additionally contains alcohol and a surfactant system which is the reaction product of N,N-dimethylethanolamine and a C₉ - C₂₂ fatty acid.
WO Patent Publication 95/03377 describes an additive combination for improving the cold flow properties of a middle distillate fuel. The additive combination comprises a copolymeric ethylene flow improver and one or more co-additives selected from an acylated amine ashless dispersant/ detergent, a fatty acid ester lubricity additive, an oil-soluble nitrate or peroxy cetane improver, and a silicon-based or acylated polyamine anti-foam agent.
Most gasolines are additized by injecting a homogeneous, low viscosity and liquid additive concentrate into the gasoline while it is being loaded into trucks at the terminal rack. Commonly such additives are diluted in an aromatic solvent (e.g., xylene, aromatic 100, heavy aromatic naphtha) to produce a homogeneous, low viscosity fluid which is suitable for rack injection.
Obviously, the additive solution must be fluid, homogenous and low viscosity under all atmospheric conditions encountered at such outdoor truck loading facilities. Unfortunately, additives such as Tolad 9103 (a mixture of polymerized fatty acids, non-polymerized fatty acids and heavy aromatic naphtha, commercially available from Petrolite Corp.) is not suitable for additization under low temperature. It turns solid by 0°F within one day.
It has been discovered that fatty acids, dimers and trimers of such acids and the esters of such acids, useful as anti friction and wear reducing additives in gasoline and diesel fuels are formulated into an additive concentrate which remains liquid at low temperatures of about -18°C (0°F) and lower by the additional presence in the concentrate of an alcohol, an amine or a mixture of alcohol and amine. The fatty acids and their esters are typically derived from naturally occurring fats and oils and includes those known as tall oil acids and their esters.
In one aspect the present invention provides an additive concentrate for gasoline comprising a lubricity additive selected from saturated and unsaturated fatty acids, dimerized or trimerized saturated and unsaturated fatty acids, esters of such fatty acid and dimerized or trimerized fatty acids and mixtures thereof in an aromatic solvent, said lubricity additive being present in the solvent in an amount of 85wt% or less and containing a compatibilizer which remains liquid to a temperature of at least about 0°C (32°F) and which comprises a mixture of a C₂ to C₁₀ alcohol and a C₁₂ to C₇₅ amine having at least one nitrogen atom wherein the compatibilizer is present in a total amount of from 10 to 50wt% based on the weight of lubricity additive and the weight ratio of alcohol to amine is from 2:10 to 10:1.
In another aspect the present invention provides the use of a C₂-C₁₀ alcohol or a C₁₂ - C₇₅ amine having at least one nitrogen atom, or a mixture thereof which remains liquid to at least 0°C (32°F) as a compatibilizing agent in an additive concentrate for gasoline which concentrate comprises a lubricity additive selected from saturated and unsaturated fatty acids, dimerized or trimerized saturated and unsaturated fatty acids, esters of such fatty acid and dimerized or trimerized fatty acids and mixtures thereof in an aromatic solvent, said lubricity additive being present in the solvent in an amount of 85wt% or less, the said compatibilising agent maintaining the additive concentrate in the liquid state at a low temperature of -18°C (0°F) or lower.
The concentrate comprises fatty acids, dimers or trimers of fatty acids, their esters and mixtures thereof in an aromatic solvent diluent and further a C₂ to C₁₀ alcohol, preferably a C₂ to C₈ alcohol, most preferably ethanol, which remains liquid at temperatures of at least as low as 0°C (32°F), a C₁₂ to C₇₅ amine having at least one nitrogen, preferably a C₁₂ to C₁₈ amine and which has a glass transition temperature or is liquid at temperatures of at least as low as 0°C (32°F), and mixtures of such alcohols and amines.
The concentrate comprises a lubricity additive selected from the group consisting of saturated or unsaturated fatty acids, dimerized and trimerized saturated or unsaturated fatty acids, their esters and mixtures thereof, preferably the acid(s), in an aromatic solvent, preferably an aromatic solvent of 8 to 14 carbons, the acid(s), ester(s) or mixture thereof being present in the solvent in an amount of about 85 wt% or less, preferably about 50 wt% or less, more preferably 30 wt% or less, and a compatibilizer selected from the group consisting of an alcohol, an amine or a mixture thereof wherein, the alcohol or amine, preferably alcohol, used individually is present in an amount of at least about 30 wt% preferably about 35 wt%, more preferably about 40 wt% most preferably about 50 wt% based on the acid(s), ester(s) or mixture thereof, preferably when the lubricity additive component concentration in the diluent is about 50 wt% or less, preferably about 30 wt% or less, most preferably about 30 wt%, and the combination alcohol plus amine is used in an amount of about 10 to 50 wt%, more preferably about 10 to 20 wt% based on the acid(s), ester(s) or mixture thereof, preferably when the lubricity additive component concentration in the solvent is about 30 wt% and higher, preferably about 50 wt% and higher. The weight ratio of alcohol to amine in the mixture is from 2:10 to 10:1, more preferably 3:10 to 10:5 most preferably 1:1.
The invention is further understood with reference to the following examples. The product names Tolad 9103, Pluradyne FD-100, Hitec 4956, Armeen HT-97, Ethomeen C/12 and Exal 8 are trade marks.

EXAMPLE 1

The data tabulated below (Table 1) (blends 17 and 18) demonstrate that additional aromatic solvent (i.e., Aromatic 100 an aromatic solvent with an average carbon number between 9 and 11) does not effectively keep Tolad 9103 lubricity additive in the fluid state. There may be some very high level of aromatic solvent which may be sufficient to keep Tolad 9103 fluid at low temperatures. However, in practice it is desirable to keep the total amount of injected material at a minimum. This reduces transportation cost of the total package. Typical injection systems also have a maximum injection volume capacity. Large amounts of volatile aromatic solvents are also undesirable from an environmental viewpoint. They increase air discharge of volatile organic compounds.

EXAMPLE 2

The following blends (Table 2) contain 10 grams of Aromatic 100 solvent and 3 grams of Tolad 9103 in addition to various compatibilizing agents. Data below demonstrate that alcohol is an effective compatibilizer of Tolad 9103. Exxal 8 (iso-octanol) and ethanol are both effective. In addition, BASF Pluradyne FD-100 (poly isobutenyl monoamine having approximately 70 carbons) is also very effective. Hitec4956, a mannich base polyamine fuel detergent sold by Ethyl, is partially effective. Armeen HT-97 an amine which is not liquid at room temperature, did not function as a compatibilizer. Ethomeen C/12 is an ethoxylated cocoa alkylamine purchased from Akzo Chemical Co.

EXAMPLE 3

The following blends (Table 3) contain 10 grams of Aromatic 100 and 5 grams of Tolad 9103. The higher concentration of Tolad 9103 necessitates more compatibilizing agent. Only one compatibilizer was most effective. This was a 50/50 mixture of Ethanol and Ethomeen C/12. Note that this 50/50 mixture was less effective in the table above, when only 3 grams of Tolad 9103 was used. A repeat of this experiment confirmed that the combination of ethanol and Ethomeen C/12 is most effective with the higher dosage of Tolad.
Another compatibilizer which is partially effective in the table below is a mixture of Exxal 8 (iso-octanol) and Ethomeen C/12.

EXAMPLE 4

The data tabulated below (Table 4) demonstrate that the compatibilizer is best if it contains more than 1 part alcohol to 9 parts amine.

EXAMPLE 5

The data tabulated below (Table 5) demonstrate that the most preferred compatibilizer is effective at low concentrations. The concentration of amine plus alcohol compatibilizer should be about 3 parts or more compatibilizer to 25 parts lubricity additive.
The additive concentrate may, of course, contain other typical components such as detergents, carrier fluids, octane boosters, antioxidants, metal corrosion inhibitor (especially copper corrosion inhibitors), and the like.

Claims

An additive concentrate for gasoline comprising a lubricity additive selected from saturated and unsaturated fatty acids, dimerized or trimerized saturated and unsaturated fatty acids, esters of such fatty acid and dimerized or trimerized fatty acids and mixtures thereof in an aromatic solvent, said lubricity additive being present in the solvent in an amount of 85wt% or less and containing a compatibilizer which remains liquid to a temperature of at least 0°C (32°F) and which comprises a mixture of a C₂ to C₁₀ alcohol and a C₁₂ to C₇₅ amine having at least one nitrogen atom wherein the compatibilizer is present in a total amount of from 10 to 50wt% based on the weight of lubricity additive and the weight ratio of alcohol to amine is from 2:10 to 10:1.
The concentrate of claim 1 wherein the alcohol is a C₂ to C₈ alcohol.
The concentrate of claim 1 wherein the alcohol is ethanol.
The concentrate of claim 1, 2 or 3 wherein the amine is a C₁₂ to C₁₈ amine.
The concentrate of any preceding claim wherein the amount of compatibilizer is from 10 to 20 wt% based on weight of lubricity additive.
The concentrate of any preceding claim wherein the weight ratio of alcohol to amine is from about 3:10 to 10:5.
The concentrate of any preceding claim wherin the amount of lubricity additive is at least 30wt%, based on the weight of aromatic solvent.
The concentrate of any preceding claim wherein the lubricity additive is selected from saturated and unsaturated fatty acids, dimerized and trimerized saturated and unsaturated fatty acids and mixtures thereof.
The concentrate of any of claims 1 to 7 wherein the lubricity additive is selected from the esters of saturated and unsaturated fatty acids, esters of dimerized and trimerized saturated and unsaturated fatty acids and mixtures thereof.
Use of a C₂ - C₁₀ alcohol or a C₁₂ - C₇₅ amine having at least one nitrogen atom, or a mixture thereof which remains liquid to at least 0°C (32°F) as a compatibilizing agent in an additive concentrate for gasoline which concentrate comprises a lubricity additive selected from saturated and unsaturated fatty acids, dimerized or trimerized saturated and unsaturated fatty acids, esters of such fatty acid and dimerized or trimerized fatty acids and mixtures thereof in an aromatic solvent, said lubricity additive being present in the solvent in an amount of 85wt% or less, the said compatibilising agent maintaining the additive concentrate in the liquid state at a low temperature of -18°C (0°F) or lower.