Ethanol
Introduction
Ethanol, also known as ethyl alcohol, is a volatile, flammable, colorless liquid that is the principal type of alcohol found in alcoholic beverages. It is also used in thermometers, as a solvent, and as a fuel. In common usage, it is often referred to simply as alcohol or spirits.
Chemistry
Ethanol is a molecular compound with the chemical formula C2H5OH. It consists of two carbon atoms (C), six hydrogen atoms (H), and one hydroxyl group (OH). The hydroxyl group (-OH) is what classifies ethanol, and any other compounds with this group, as an alcohol.
Production
Ethanol can be produced both synthetically from petrochemicals such as ethylene, and by fermentation of sugars by yeast. The latter method is more common for the production of alcoholic beverages, while the former is more common for industrial uses.
Synthetic Production
In the petrochemical industry, ethanol is produced by the hydration of ethylene in the presence of a catalyst such as phosphoric acid. The reaction is as follows:
C2H4 + H2O → C2H5OH
Fermentation
In the production of alcoholic beverages, ethanol is produced by the fermentation of sugars by yeast. The process is as follows:
C6H12O6 → 2 C2H5OH + 2 CO2
This process is used in the production of wines, beers, and spirits.
Uses
Ethanol has a wide range of uses, from being a psychoactive drug in alcoholic beverages, to being a solvent in the chemical industry, to being a fuel for engines.
Alcoholic Beverages
Ethanol is the principal type of alcohol found in alcoholic beverages. It is produced by the fermentation of sugars by yeast.
Solvent
Ethanol is a good solvent and is used in a wide range of products including paints, varnishes, and perfumes.
Fuel
Ethanol is also used as a fuel for engines, particularly in flex-fuel vehicles which can run on a blend of gasoline and ethanol.
Health Effects
Ethanol has a number of effects on the human body. It is a psychoactive drug and its consumption can lead to short-term effects such as euphoria, reduced anxiety, and sociability. Long-term effects can include physical dependence and a range of health problems including liver disease and neurological damage.
Environmental Impact
The production and use of ethanol as a fuel can have a number of environmental impacts. On the positive side, it is a renewable resource and its combustion releases less greenhouse gases than the combustion of fossil fuels. However, the cultivation of crops for ethanol production can lead to deforestation and loss of biodiversity.