Ethanol

Figure 1. Space filling model of ethanol, here the black is carbon, the white is hydrogen and the red is oxygen.[1]

Ethanol is a simple alcohol, also referred to as ethyl alcohol or drinking alcohol. It is a common alcohol that can be burned as fuel. It's chemical formula is C2H6O and it is a clear, colourless liquid with a characteristic alcoholic odour.[2] Ethanol is primarily used as a solvent when making varnishes and perfumes and as a preservative for biological specimens. As well, ethanol is used as a disinfectant and is consumed as a drink.[3] A special type of ethanol, known as bioethanol is used as a gasoline additive or an alternative fuel source.

Similar to other hydrocarbons such as butane, ethanol undergoes hydrocarbon combustion when used as fuel.

Production

Ethanol can be produced in two ways, using either petroleum or biomass. The ethanol produced using biomass is known as bioethanol, and this process is explained on the bioethanol page. For the petroleum production, in large chemical plants raw materials separated from petroleum can be converted to ethanol through hydration processes, which is basically letting the raw materials react with water. Usually the process requires a catalyst (often phosphoric acid) added under an excess of high pressure steam to the reaction chamber to increase the reaction rate, so that more ethanol will be produced.

Properties

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

Formula C2H6O
Molar mass 46.07 grams/mole
Energy density 29.7 MJ/kg[4]
Melting Point -114.1oC[2]
Boiling Point 78.2oC[2]

Combustion Animation

Ethanol is used as a combustible fuel. Below is an animation showing the net reaction that occurs during the combustion of ethanol. It should be noted that ethanol requires oxygen to undergo combustion. While the CO2 will eventually be taken up in plant matter, it isn't immediate, see carbon dioxide atmospheric residence time.

References

  1. "Ethanol-3D-vdW" Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Ethanol-3D-vdW.png#mediaviewer/File:Ethanol-3D-vdW.png
  2. 2.0 2.1 2.2 National Center for Biotechnology Information. (2015). Properties of Ethanol [Online]. Available: http://pubchem.ncbi.nlm.nih.gov/compound/ethanol#section=Top [February 16,2015].
  3. Infoplease. (2012). Uses of Ethanol [Online]. Available: http://www.infoplease.com/encyclopedia/science/ethanol-uses.html [February 16, 2015].
  4. Glenn Elert. (2015). The Physics Hypertextbook - Chemical Potential Energy [Online]. Available: http://physics.info/energy-chemical/ [February 16, 2015].

Authors and Editors

Jordan Hanania, James Jenden, Kailyn Stenhouse, Jason Donev