Kerosene
Kerosene is a combustible liquid fuel, also derived from crude oil, sitting between gasoline and diesel in terms of weight and refining profile. It’s a hydrocarbon mix with molecules typically having 10 to 16 carbon atoms, extracted during distillation at a boiling range of about 150–275°C (302–527°F). Lighter than diesel but heavier than gasoline, it’s less volatile than gas and has an energy content of roughly 35 megajoules per liter (or 125 MJ per gallon), making it a versatile middle-ground fuel.
Kerosene’s cleaner burn compared to coal or wood made it a staple in the past, but it’s not without downsides, spills can pollute, and burning it still pumps out CO2. It’s less common in road vehicles because it lacks the ignition properties of gasoline or diesel for those engines.
Kerosene Types
- Jet A - Used mainly in the U.S., has a higher freezing point.
- Jet A-1 - International standard, lower freezing point.
- Jet B - A blend with gasoline, used in extremely cold conditions.
- Hydrocarbons (95-99%)
- Alkanes (Paraffins) - Straight and branched chains like n-decane and n-dodecane. Typically 60-75%. These contribute to kerosene’s clean-burning properties.
- Cycloalkanes (Naphthenes) - Cyclic saturated hydrocarbons, like methylcyclohexane. About 10-20%.
- Aromatics - Monocyclic and polycyclic compounds, like toluene and naphthalene. Usually 10-25%, with stricter limits (e.g., <8-25% for aviation kerosene like Jet A-1 to reduce smoke and emissions).
- Additives (<1-5%, depending on use)
- Antioxidants - Hindered phenols to prevent oxidation during storage.
- Static Dissipators - Conductive compounds to reduce static charge risks in aviation fuel.
- Corrosion Inhibitors - Carboxylic acids or amines to protect fuel systems.
- Anti-icing Agents - Ethylene glycol monomethyl ether in jet fuels to prevent ice formation (0.1-0.3%).
- Lubricity Enhancers - Fatty acid derivatives for pump and injector durability.
- Biocides - Used in some storage scenarios to prevent microbial growth.
- Dyes - Red or blue for tax/grade identification in non-aviation kerosene.
- Trace Impurities (<1%)
- Sulfur Compounds - Thiophenes, mercaptans (typically <0.003% or 30 ppm in aviation kerosene, up to 0.3% in heating kerosene).
- Nitrogen/Oxygen Compounds - Trace amines, phenols from crude oil.
- Metals - Nickel, vanadium in parts per billion (ppb).