Energy

What it is for

Coal is a widely used energy source and it is the main fuel source for the production of electric energy. Many countries strongly depend on electricity deriving from coal: in 2010 China consumed 1713,4 million toe, USA 524 million toe and India 277  million toe (Source: BP Statistical Review of World Energy 2011). In electric energy plants the coal is burnt to heat water until it turns into steam that, under pressure, turns a turbine, which is connected to a generator. The mechanic energy of rotation is then transformed into electric energy. Approximately 39% of the electricity produced in the world comes from coal. Moreover, in developing countries the use of coal is still important for household tasks: heating and food cooking. The steel and metal industry uses coke: it is a solid and hard fuel obtained by heating the coal at high temperature. Coke is the raw material to produce steel. Other industrial processes use coal gases to produce fertilisers, pharmaceuticals, pesticides, etc. Tar is also obtained from coal through distillation. The natural dislike of its colour and smell did not prevent the chemistry experts of the 1700s from discovering its virtues: wood painted with tar becomes water proof and resilient against microbes. Moreover, in developing countries coal is still used for household tasks: heating and food cooking.