Figure 1. A butane torch for kitchen use (specifically for crème brûlée).[1]

Butane is an alkane with the chemical formula [math]\ce{C4H10}[/math], as shown in Figure 2. As a type of hydrocarbon, it can undergo hydrocarbon combustion which releases heat energy. Butane is one of the hydrocarbon components of raw natural gas, which is a type of fossil fuel.[2] Butane is usually removed from natural gas before being shipped to customers, but then butane is sold separately as a fuel itself.

At typical temperatures and pressures butane is a gas and either by itself, or mixed with propane ([math]\ce{C3H8}[/math]), makes liquefied petroleum gas (LPG).[3] The percent of butane and propane in LPG varies based on what LPG is used for and the climate of where it is used.[3] LPG could even be entirely propane.

Butane is also commonly mixed with propane in camping fuel in order to maintain higher pressures at low temperatures.[4] Butane is as well one of the main components in lighter fluid and is commonly used in cigarette lighters, portable stoves and butane torches. Figure 1 shows a butane torch used for cooking purposes.


Figure 2. Space filling model of butane, the white spheres represent hydrogen and the black spheres represent carbon.[5]

Below is a table of some of the basic properties of butane.

Formula C4H10
Molar mass 58.12 grams/mole
Energy density 49.5 MJ/kg[6]
Melting Point -138oC[7]
Boiling Point -0.5oC[7]

Combustion Reaction

Butane releases its chemical energy by undergoing hydrocarbon combustion. Below is a hydrocarbon combustion animation showing the net reaction that occurs when butane combines with oxygen.

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O + Heat Energy (Enthalpy)

The hydrocarbon combustion reaction releases heat energy and is an example of an exothermic reaction. The reaction also has a negative enthalpy change (ΔH) value.

For Further Reading


  1. [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons accessed 1/29/2015.
  2. “NATURAL GAS FAQs,” Pacific Northern Gas RSS. [Online]. Available: http://www.png.ca/natural-gas-faqs/. [Accessed: 24-May-2017]
  3. 3.0 3.1 Hahn, E. (2020). What is the Percentage of Propane and Butane in LPG Gas Mixture - Which Gas is Present in LPG. [online] Elgas.com.au. Available at: https://www.elgas.com.au/blog/1972-lpg-contains-which-gases-gases-present-in-lpg-gases-used [Accessed 26 Jan. 2020].
  4. MSR.(2014). MSR ISOPRO - Performance Boosting Fuel for your Canister Stove [Online]. Available: http://www.cascadedesigns.com/msr/stoves/stove-accessories/msr-isopro/product [February 16, 2015].
  5. "Butane-3D-space-filling". Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Butane-3D-space-filling.png#mediaviewer/File:Butane-3D-space-filling.png
  6. Glenn Elert. (2015). The Physics Hypertextbook - Chemical Potential Energy [Online]. Available: http://physics.info/energy-chemical/ [February 16, 2015].
  7. 7.0 7.1 Charles E. Ophardt. (2003). Virtual Chembook - Hydrocarbon Boiling Points [Online]. Available: http://www.elmhurst.edu/~chm/vchembook/501hcboilingpts.html [February 16,2015].