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Propane VS Butane – Their Similarities and Differences

propane gas cylinder

Propane and butane are two gases that are strikingly similar to each other yet considerably different. Often, one is used and preferred over the other one in certain circumstances and conditions, even though they are known to be extremely similar in characteristics, behaviour and properties. What are the key differences between these two gases and what makes them identical? Let’s discover it in this blog.

Similarities Between Propane and Butane

  • Propane and Butane are both “hydrocarbon gases”

Hydrocarbons are molecules composed of hydrogen and carbon atoms, and they can exist in various forms such as gases, liquids, or solids. Propane has three carbon atoms and eight hydrogen atoms, while butane has four carbon atoms and ten hydrogen atoms. Both propane and butane are commonly used as fuels for heating and cooking appliances due to their flammable nature and high energy content.

• Propane and Butane are both colourless

Both propane and butane are colourless, meaning that they do not have any visible colour. This is because pure propane and butane do not absorb any visible light in the electromagnetic spectrum. However, it is important to note that when propane or butane is mixed with other gases or impurities, it can take on a yellowish or brownish tint.

  • Propane and Butane are both eco-friendly

Propane and butane are both comparatively eco-friendly when compared to other fossil fuels. Their combustion is effective, they are both renewable sources of energy and produce lower emissions than standard fossil fuel when used. Using a propane gas cylinder or a butane gas cylinder instead of fossil fuels or harmful toluenes will greatly help the ecosystem deal with the rising levels of pollution.

  • Propane and Butane are obtained from same sources

Propane and butane are both derived from petroleum and are produced through a refining process that separates and purifies the hydrocarbon compounds from its component compounds. Petroleum products like natural gas or crude oil can be used to obtain propane and butane.

The natural gas/crude oil is first extracted and separated from its component substances. After that it is refined, compressed and distributed into containers for transport such as a propane gas cylinder or a butane gas cylinder

  • Propane and Butane are both flammable and reactive

Propane and butane, both being hydrocarbon gases, are also similar in one dangerous attribute – they both are reactive and flammable. Even a slight ignition can be the cause of fires and explosions. That is why it is always recommended to handle these gases with care.

Propane and butane are also highly combustible, meaning that they react rapidly with oxygen in the air to release energy in the form of heat and light. This property makes them useful as fuels for heating, cooking, and powering engines. Propane is known for violently reacting with oxidizing agents such as chlorine dioxide while butane is also known for reacting to similar oxidizing agents.

Differences Between Propane and Butane:

  • Propane and Butane have different weights and densities

Propane and butane both are gases that are heavier than air. Compared to air (1.225 kg/m³), butane and propane weigh 2.5436 kg/m³ and 1.898 kg/m³ respectively. This difference allows them to be used in a variety of ways and makes them both more versatile and compatible with each other. Propane is also more dense than butane.

Propane can be used in places where a lighter gas is required such as pipes that travel upwards or vents that travel upwards, whereas butane can be used in places where you don’t want the gas to travel much higher up, like a storage unit or a butane gas cylinder.

• Propane is odourless while Butane has a petroleum-odour

Pure propane is odourless and colourless. That’s why sometimes an odorant is added to propane for detection in case of leaks or mishaps. On the other hand, butane has a significant petroleum odour that helps it to be distinguished easily. The odour of petroleum in butane can be described as a faint yet recognizable odour.

• Propane and Butane have different boiling points

Perhaps the most important factor that differentiates these two gases is their standard boiling point. Propane has a boiling point of -42 °C which makes it incredibly liquefied under elevated pressures.

Butane has a standard boiling point of -1 °C which makes propane burn significantly hotter than butane, thus making it useful in industrial uses or indoor/home uses where it is favoured more than propane, while propane is favoured extremely well for outdoor combustion conditions thanks to its low boiling point.

• Propane burns a little hotter than Butane

Butane has a higher boiling point than that of propane, making it easier for propane to create more heat and release more energy than butane. Propane can reach up to levels such as 3,560˚ F while burning, releasing intense and clean heat waves while butane can reach up to 2,610 °F while burning, which is still good and very useful in most conditions.

• Propane and Butane have different vapor pressures

Propane and butane have different vapor pressures which make them behave differently than each other in certain conditions and environments. Vapor pressure is the rate of pressure at which a liquid or solid turns into a gas.

Butane’s lower vapor pressure makes it suitable for pressurized environments like when it’s used as a propellant for aerosol canisters while propane’s denser attributes hold more litres in containers such as a one-kilogram LPG cylinder or a standard propane gas cylinder.

Propane has at least triple the vapor pressure of that of butane. The higher vapor pressure of propane makes it a better choice for colder climates.


Both propane and butane have their unique features and benefits. The choice between the two depends on your specific needs and intended use. Here at Kenny Fuels, we supply both propane gas cylinder and butane gas cylinder to all parts of Wexford, Wicklow, and Carlow. We believe in offering our customers the best quality fuel at affordable rates. Place your orders on our website today.


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