Kerosene types and gradations

Kerosene is a quite generic term and also known as Paraffin, lamp oil, Jet-Fuel or Petroleum and can be used in camping stoves, heaters and lamps. It is usually made from crude oil by cracking and distillation. The distillation is done at different temperatures in order to obtain different fractions based on their boiling- and condensation temperature. The substances in a fraction have a certain molecule size because the molecule size strongly relates to the boiling point and condensation point. Kerosene products have a boiling range of approximately 150 to 290 °C (302 to 554 °F) and a carbon range of approximately C9 –C16. Usually a treatment with hydrogen is also done prior to the distillation. Besides breaking larger molecules into smaller ones it will also transform aromatic benzene rings into cyclohexane and transform sulfur into H2S which is then removed. Labels will often state: Dearomatized and desulphurized. The resulting mixtures of substances that have common properties such as molecule size, boiling point, and flash-point are sold under different names and labels. Kerosene in particular is sold in different molecule size gradations. The larger the molecules, the larger it’s flash-point. If the molecule size is not mentioned on a product label, the flash-point often is. Besides usage as fuel it is also used as lubricant and as solvent. Hence the flammability of WD40 and paint additives such as brush cleaners (turpentine, white spirit).

The range of carbon atoms per molecule is often found on the label on bottles with lamp oil, turpentine, white gas, kerosene for heaters etc. The longer the molecules are the more energy content. Also the oxygen demand will increase with the increase of the molecule length. A lack of oxygen will often result in yellow flames instead of blue ones. Smaller molecules are easier to ignite.

Camping gas C3-C4 In other words Butane and Propane. Easy to ignite as there is no need for preheating to ensure gasification. Soot formation on cookware due to yellow flames is rare. In recent decades this became the most popular camping fuel due to its ease of use. Downside is that the heat output per volume is small and canisters are sometimes difficult to find. Another downside is usage under cold weather conditions. Due to the boiling point at -1 ºC from Butane it can become liquid and pressure int he canister will be lost.

Camp fuel C5-C9
Usually Light Hydrotreated Distillate CAS number 68410-97-9 is the main ingredient in Camp fuel. The most famous is Coleman Fuel, other brands are Crown camp fuel and Primus Power Fuel. Labels will show a flame symbol to indicate it’s high flammability. The flashpoint is far below 0 ºC. The liquid itself can be set afire with a lighter so it can be used as a preheating material for camping stoves. Normal automotive fuel can be used as an alternative. However this can lead to clogging of the generator in most camping stoves. A cleaner less smelling alternative is Alkylate Fuel such as Aspen 4.

Petroleum C9-C11. Not very often found due its lower flashpoint at 39 ºC and therefore tighter rules for transport and storage. Although lubricants such as WD40, low aromatic paint thinner and brush cleaner tend to use this grade of petroleum. Labels will often show a flame symbol to indicate it’s high flammability. Although it is nearly impossible to set it afire with just a lighter. Having the flashpoint at 39 ºC would suggest that maybe in hot tropical weather conditions you might succeed in doing so. This grade can be used in classic camping stoves such as the Primus 96, Primus 210, Optimus 45 etc. Just like other kerosene grades it is necessary to preheat camping stoves with alcohol or camp fuel. Usually it will burn with a nice blue flame and it is easier to ignite in cold weather conditions then heavier petroleum grades.

Petroleum C10-C13 Very often sold as petroleum for classic kerosene stoves, wick stoves and oil lamps. Unlike Petroleum C9-C11 it is not labeled with a flame symbol for high flammability. It’s flashpoint is 65 ºC. Therefore regulations for storage and transport are less strict. As a result it is one of the most common found petroleum grades.

Petroleum C14-C17. Not very often found. Petroleum grades with C14 and higher components will burn safely and good in Kerosene heaters but will flare up with yellow flames in most camping stoves.

Grades of Paraffins (Kerosene) made by Sasol. Source:

Lamp oil: C10-C13 + C8-C26. Perfect for oil lamps because it will produce nice yellow flames. Unsuitable for most camping stoves as it will lead to smoke, smell and flare up of yellow flames. Easily available in supermarkets and camping supply shops. Please note that products sold as ”lamp oil” can contain all kinds of kerosene gradations as flat wick lamps will easily burn on it. Some sellers of classic oil lamps advise to stay away from products labeled as lamp oil and instead use refined colorless grades of kerosene to avoid soot formation.

Kerosene for kerosene heaters: C11-C16. The molecule range is a on the high side but not too much. In this way the flashpoint and boiling point are high enough to avoid dangerous situations but is still low enough to ensure a complete burning of the fuel so smell is avoided. By using kerosene with relatively high molecule sizes the heat output per volume is also higher. Most suppliers of kerosene for heaters will sell 2 different grades; suitable for indoor usage and suitable for outdoor usage only. The last one is made by classic cracking and distillation while the other is made synthetically with the so called Fischer–Tropsch process. In this process gasses (small molecules) are combined into larger molecules that are liquid. Hence the name GTL fuel, Gas To Liquid. These fuels have a extreme low aromatic compound content. Since aromatic compounds are liquids at room temperature while the starting materials for this fuel are gasses they simply cannot be there. They are known for smooth and clean burning.

Published by dreweszuur


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