Iron-containing fuel additive for reducing particulates generated during combustion

An oil soluble fuel additive for mixing with a liquid hydrocarbon fuel for reducing smoke during combustion of the hydrocarbon fuel, the additive comprising:

• an oil-based solvent;
• an oil-soluble iron compound dissolved in the solvent;
• at least one other oil-soluble transition metal compound dissolved in the solvent selected from the group of platinum-group metal compounds, manganese, cerium, and mixtures thereof;
• and
• optionally, an additional metal compound dissolved in the solvent, the additional metal compound comprising a metal selected from the group consisting of an alkaline earth metal, a rare earth metal, a lanthanum series metal, or an actinide series metal.

A liquid fuel suitable for use in a jet turbine engine, comprising:

• a jet-fuel-grade kerosene;
• and
• a fuel additive dissolved in the kerosene, the fuel additive comprising:
• an oil-soluble iron compound present in the hydrocarbon in a range from about 1 ppm to about 50 ppm;
• an oil-soluble platinum-group compound selected from the group of Pt compounds, Pd compounds, Ir compounds, and mixtures thereof, the platinum-group compound being present in the liquid fuel in a range from about 0.01 ppm to about 10 ppm;
• and
• at least one of an oil-soluble manganese compound or a magnesium compound present in the liquid hydrocarbon in a range from about 1 ppm to about 100 ppm.

A liquid fuel suitable for use in a jet turbine engine, comprising:

• a jet-fuel-grade kerosene;
• and
• a fuel additive dissolved in the kerosene, the fuel additive consisting essentially of:
• an oil-soluble iron compound present in the hydrocarbon in a range from about 1 ppm to about 50 ppm;
• an oil-soluble manganese compound present in the liquid hydrocarbon in a range from about 1 ppm to about 100 ppm;
• and
• optionally, at least one of an oil-soluble platinum-group compound, an alkaline earth metal compound, or cerium.