ethanol

Alcohol found in beer, wine, cider, spirits, and other alcoholic drinks. When pure, it is a colourless liquid with a pleasant odour, miscible with water or ether; it burns in air with a pale blue flame. The vapour forms an explosive mixture with air and may be used in high-compression internal combustion engines.

It is produced naturally by the fermentation of carbohydrates by yeast cells. Industrially, it can be made by absorption of ethene and subsequent reaction with water, or by the reduction of ethanal (acetaldehyde) in the presence of a catalyst, and is widely used as a solvent.

Ethanol is used as a raw material in the manufacture of ethoxyethane (ether), trichloroethanol (chloral), and triiodomethane (iodoform). It can also be added to petrol, where it improves the performance of the engine, or be used as a fuel in its own right (as in Brazil). In August 2001 it was discovered that when ethanol is added to petrol it boosts the oxygen content, reducing the emissions of air-polluting gases. Crops such as sugar cane may be grown to provide ethanol (by fermentation) for this purpose.

In the USA, mainly in the mid-western states, 10% ethanol is added to petrol.