Fuel additive, additive-containing fuel compositions and method of manufacture

Abstract

The present invention relates to fuel additives, fuel compositions and methods of manufacture in which the additives are provided to impart desired properties to fuels. These properties include, without limitation, reduction of nitrogen oxide and particulate emissions from the exhaust stream of internal combustion engines using the fuels. Preferred embodiments of an additive form of the composition include a nitrogen-containing compound selected from the group consisting of urea, cyanuric acid, triazine, ammonia and mixtures thereof, a carrier blend comprising an alkoxylated alcohol, a polyalkylene glycol ester and an alkanolamide and water. The additive may be provided in a concentrate form by addition of a solvent or may be provided as a final form fuel composition. A method of additive manufacture and is disclosed.

Description

[0001] This invention is related generally to fuel additives and to fuels formulated with the additives and a method of manufacture.[0002] Reduction of internal combustion engine exhaust emissions is a fundamental problem confronting the automotive industry worldwide. Nitrogen oxide ("NO.sub.x") emissions are a class of engine exhaust emissions which are coming under increasingly strict regulatory scrutiny because of their asserted affect on the environment. NO.sub.x emissions from internal combustion engines are, for example, asserted to be precursors in the formation of ozone and are further asserted to be responsible for the formation of other types of air pollution, such as smog.[0003] Diesel engines present a further problem for the automotive and transportation industry in that the exhaust emissions from these type of engines typically include large amounts of particulates together with NO.sub.x. The particulate emissions are present in the black smoke discharged from the engi...

AI Technical Summary

Benefits of technology

0056] The inventive composition is highly effective in solubilizing nitrogen-containing compounds in the fuel. The nitrogen-containing matter enters the engine combustion chamber as part of the fuel and reacts during combustion to reduce NO.sub.x emissions. By providing the nitrogen-containing compound as a component of the host fuel it is possible to avoid any necessity for the use of complex and costly mechanical apparatus used to feed nitrogen-containing compounds to the engine combustion chamber or to the engine exhaust stream. The invention is powerfully efficacious versus prior art compositions, such as U.S. Pat. No. 5,746,783 (Compere et al.), because less nitrogen is required in the fuel and because far less constituents are required to keep the nitrogen in the fuel, a benefit which provides important cost-savings benefits.

0057] Without wishing to be bound by any particular theory, it is believed that the fuel additive of the, invention is effective in producing a stable, single phase additive, concentrate and final form fuel in large part because of the nature of the carrier blend. The nonionic carrier blend is highly efficacious in solubilizing low molecular weight polar nitrogen-containing compounds into non-polar matrices, such as hydrocarbon-containing fuels.

0058] Again, and without wishing to be bound by any particular theory, it is believed that combustion of the nitrogen-containing composition(s) in the fuel within the engine cylinder causes the nitrogen-containing composition to become decomposed and to form reactive species which react with the NO.sub.x emissions. It is thought that the cyanuric acid, triazine and ammonia react to form urea intermediaries which are further decomposed to react with the NO.sub.x emissions. The resultant reactions produce nitrogen gas (N.sub.2)and water. By providing the nitrogen-containing composition as an integral component of the fuel, it is possible to continuously maintain the level of the reactive nitrogen-containing composition throughout the combustion process thereby maximizing the amount of NO.sub.x emission reduction.

Problems solved by technology

Reduction of internal combustion engine exhaust emissions is a fundamental problem confronting the automotive industry worldwide.

Diesel engines present a further problem for the automotive and transportation industry in that the exhaust emissions from these type of engines typically include large amounts of particulates together with NO.sub.x.

While these emission-control devices are effective in decreasing particulate emissions, they do not appear to be effective in reducing NO.sub.x emissions.

However, these known emission control systems and strategies have associated disadvantages.

All of the aforementioned NO.sub.x-reducing systems are disadvantageous because of the extensive and costly mechanical structure required for operation of the systems.

While possibly effective in reducing NO.sub.x emissions, this system disadvantageously requires costly mechanical and catalytic components.

The system of the Rao patent disadvantageously requires the use of complex and costly mechanical apparatus in order to introduce the correct amount of reducing agent into the combustion chamber.

These compositions, while efficacious in certain applications, are not optimally effective in reducing NO.sub.x emissions and are not effective in solubilizing NO.sub.x-reducing agents.

While reportedly effective in reducing diesel a fuel emissions generally (as a result of reducing the percentage of diesel fuel in the composition) the Aluned composition does not disclose any specific assertion of NO.sub.x or particulate emission reduction.

The composition of the Compere patent is disadvantageous because it requires higher levels of urea than are needed to reduce NO.sub.x.

Moreover, the composition requires higher levels of solubilizing agent to maintain the urea in the composition than are practical or economical.

It is expected that a fuel containing the composition would have lower BTU and a lower cetane number / index with resulting disadvantages, such as potentially causing the fuel to be outside of standard specifications.

In addition it can be demonstrated that the use of a fuel containing this composition would not be clear or homogeneous at the higher fuel dilutions utilized in the industry.

Further, low sulfur and ultra low sulfur diesel fuels presently being manufactured lack lubricity as a result of the low sulfur content of the fuels.

Reduced lubricity contributes to engine wear and reduces the distance that the vehicle can travel per unit volume of fuel.

Moreover, a significant material-handling issue confronting the possible use of non-ionic surfactants in fuel compositions involves the lack of liquidity of many non-ionic surfactants.

The addition of solvents adds to the cost of transport and, potentially, may create difficulties in mixing the additive with the fuel.

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