An aviation fuel is formulated with manganese-containing compounds. The composition may include relatively high amounts of manganese up to about 500 mg Mn/l. A manganese-containing additive may reduce the smoke created during the combustion of the aviation fuel. Additionally, the aviation fuel composition may include manganese to improve octane and include a phosphorus-containing scavenger to reduce manganese oxide engine deposits. Further, isooctane is added in order to, with the manganese-containing compound, improve the octane number of the fuel.

An aviation gasoline composition comprising an impure iso-octane fraction, at least one xylene and at least one C.sub.4 or C.sub.5 alkane, wherein the impure iso-octane fraction in said composition is a fraction comprising at least 90 mol % iso-octane and having a final boiling point of at least 180 C. and is present in the composition in an amount in the range of from 30 to 80 vol. % based on the composition, the composition is substantially free of any lead compounds, the composition has a motor octane number of at least 94 and the composition has a final boiling point of at most 170 C. The composition of the present invention may be made by blending together an impure iso-octane fraction, xylene, at least one C.sub.4 or C.sub.5 alkane, optionally ethyl tertiary butyl ether, and optionally methylcyclopentadienyl manganese tricarbonyl and may be used in a spark ignition aviation engine, either alone or in combination with methanol or a methanol and water mixture.

An aviation fuel is formulated with manganese-containing compounds. The composition may include relatively high amounts of manganese up to about 500 mg Mn/l. A manganese-containing additive may reduce the smoke created during the combustion of the aviation fuel. Additionally, the aviation fuel composition may include manganese to improve octane and include a phosphorus-containing scavenger to reduce manganese oxide engine deposits. Further, isooctane is added in order to, with the manganese-containing compound, improve the octane number of the fuel.

An aviation fuel is formulated with manganese-containing compounds. The composition may include relatively high amounts of manganese up to about 500 mg Mn/l. A manganese-containing additive may reduce the smoke created during the combustion of the aviation fuel. Additionally, the aviation fuel composition may include manganese to improve octane and include a phosphorus-containing scavenger to reduce manganese oxide engine deposits.

A process based on the combined use of yttrium and magnesium to inhibit vanadium corrosion of high temperature parts of thermal equipment. The combined use of yttrium and magnesium, applied in a variable yttrium/magnesium ratio, compared with conventional magnesium inhibition, may reduce emission of magnesium vanadate and minimize losses of performance due to fouling of the high temperature parts, including in the presence of alkali metals. Further, compared with inhibition based on yttrium alone, it may reduce the inhibition cost and reinforce the protection against combined vanadium pentoxide and sodium sulfate corrosion.

A fuel additive composition comprises (a) a Mannich reaction product and (b) a polyetheramine where the weight ratio on an actives basis of component (a) to component (b) is 1:4-10. A fuel composition and a method for removing intake valve deposits and combustion chamber deposits in a spark-ignited internal combustion engine comprise the fuel additive composition which is very effective in removing the deposits.

A fuel additive includes methyl tert-butyl ether in an amount between 35% and 55% by weight, saturated hydrocarbons in an amount between 25% and 35% by weight and methylcyclopentadienyl manganese tricarbonyl in an amount between 3% and 12% by weight.

A method of introducing additives to an air intake system of an engine in order to overcome one or more of the various problems created by formulation of additives in fuels. The method controls at least one of the amount, aerosol particle size and timing of introduction of additives based on information relevant to operation of the engine. The introduced additives form an air-additive mixture and are carried by the airflow in the air-intake system to the combustion chamber of the engine. Another aspect of the invention is an additive introduction system that includes one or more containers for additives, a control system for determining at least one of the amount, aerosol particle size and timing of introduction of the additives, and a device to introduce the additives into the air intake system under the control of the control system.

In order to blend fuels to meet specific regulatory and industry requirements, for instance octane requirements, different octane blending components can be used. One added component includes a composition of higher aromatics content. Unfortunately, this aromatic content may increase the particulate emissions of an internal combustion engine when the high aromatic fuel is combusted in that engine. As explained herein, reducing the aromatics content and replacing that octane increasing requirement with an alternative octane enhancer results in a formulated fuel that will have lower particulate emissions in the real-world driving of that engine as compared with a fuel having higher aromatic content.

The invention relates to a material consisting of a preparation made from a mixture of ferrocene and an inert flameproof material such as plaster, the material being presented in the form of granules and being suitable for spreading over a hydrocarbon fire in a simple and rapid manner such that, under the effect of the heat from the fire, the ferrocene contained in the granulated material is diffused progressively and homogeneously in a vapour phase over the base of the flames, so as to optimise the combustion of the hydrocarbon and to reduce the emission of smoke and unwanted particles.