Uses of Alcohols
Methanol’s main use is as a chemical feedstock. Industrially methanol is converted to methanal (formaldehyde) by catalytic oxidation. Methanal is used in the manufacture of plastics, paints, explosives, textiles and cosmetics.
Methanol is used as a solvent for inks, adhesives, resins and dyes. It is also used as a solvent in the pharmaceutical industry. It is used in antifreeze for automotive radiators and screen wash.
Methanol is seeing increasing use as a fuel for internal combustion engines. It is also used as an additive in petrol to improve combustion.
The alcohol content of alcoholic drinks such as wines and beers is ethanol.
Ethanol, like other alcohols undergoes complete combustion when heated in the presence of air. It burns with a clean smokeless flame and is used as a transportation fuel or is blended with petrol.
Ethanol + air → carbon dioxide + water
2C2H5OH(l) + 6O2(g) → 4CO2(g) + 6H2O(l)
In countries like Brazil with limited natural oil supplies but ideal conditions for growing sugar cane, large scale fermentation is used to produce ethanol to be used as a fuel. Ethanol produced by fermentation is a renewable fuel. This is because the sugar cane can be replaced or grown again. It is also a more carbon friendly source of fuel because the glucose provided for the fermentation is produced by the plants by absorbing carbon dioxide from the atmosphere. When the ethanol is burnt the carbon dioxide returns to the atmosphere. The long term impact of using sugar cane as a source for fuel in Brazil is that in order to meet increasing demand rainforests may be cleared to make way for the extensive land required for farming sugarcane. This will impact the local ecosystems and the sugarcane may not have the same carbon dioxide removal potential as the rainforests they replace.
Ethanol is used as a solvent. It is also used to dissolve organic compounds which are not soluble in water. It is used in perfumes, cosmetics, paints, detergents and inks.
Ethanol has antiseptic properties it slows or stops the growth of micro-organisms (germs). Ethanol causes proteins in the micro-organisms to change their shapes not allowing them to carry out their functions properly. The loss in shape of a protein in called denaturation and it happens when the bonds that hold the protein together to maintain its specific shape are broken. For this reason ethanol is used in hand sanitisers and hand wipes.
Propanol’s main use is as a solvent. It is widely used as a solvent in printing ink. It is also used in the manufacture of cosmetics and in the pharmaceutical industry. Like ethanol, propanol also has antiseptic properties and is used in hand sanitisers and hand wipes.
Butanol is used in the manufacture of butyl ethanoate an ester used as synthetic fruit flavouring in the food and confectionary industry.
Butanol is used as a solvent perfumes, cosmetics, paints, detergents and inks.
There is increasing use of butanol as a biofuel produced from the fermentation of sugars and carbohydrates (bio-butanol) as a transportation fuel.