Uses of coal Research Paper Example | Topics and Well Written Essays - 1000 words

Uses of coal - Research Paper Example Coal is a fossil fuel and is the altered remains of prehistoric vegetation that originally accumulated in swamps and peat bogs. The energy we get from coal today comes from the energy that plants absorbed from the sun millions of years ago. All living plants store solar energy through a process known as photosynthesis. When plants die, this energy is usually released as the plants decay. Under conditions favorable to coal formation, the decaying process is interrupted, preventing the release of the stored solar energy. The energy is locked into the coal. Coal formation began during the Carboniferous Period - known as the first coal age - which spanned 360 million to 290 million years ago. The build-up of silt and other sediments, together with movements in the earth's crust - known as tectonic movements - buried swamps and peat bogs, often to great depths. With burial, the plant material was subjected to high temperatures and pressures. This caused physical and chemical changes in th e vegetation, transforming it into peat and then into coal. (World Coal Association) Coalification The quality of each coal deposit is determined by: varying types of vegetation from which the coal originated depths of burial temperatures and pressures at those depths length of time the coal has been forming in the deposit The degree of change undergone by a coal as it matures from peat to anthracite is known as coalification. Coalification has an important manner on coal's physical and chemical properties and is referred to as the 'rank' of the coal. Ranking is determined by the degree of transformation of the original plant solid to carbon. The ranks of coals, from those with the least carbon to those with the most carbon, are lignite, sub-bituminous, bituminous and anthracite. Initially the peat is transformed into lignite or 'brown coal' - these are coal-types with low organic maturity. In contrast to other coals, lignite is quite soft and its color can array from dark black to various shades of brown. Over many more millions of years, the continuing effects of temperature and pressure produces further change in the lignite, progressively increasing its organic maturity and transforming it into the range known as 'sub-bituminous' coals. (World Coal Association) Further chemical and physical changes occur until these coals became harder and blacker, forming the 'bituminous' or 'hard coals'. Under the right conditions, the progressive increase in the organic maturity can continue, finally forming anthracite. (World Coal Association) In addition to carbon, coals contain hydrogen, oxygen, nitrogen and varying amounts of sulphur. High-rank coals are high in carbon and therefore heat value, but low in hydrogen and oxygen. Low-rank coals are low in carbon but high in hydrogen and oxygen content. Coal is one of the world’s most important sources of energy, fuelling almost 40% of electricity worldwide. In many countries this figure is much higher: Poland rel ies on coal for over 94% of its electricity; South Africa for 92%; China for 77%; and Australia for 76%. Coal has been the world’s fastest growing energy source in recent years – faster than gas, oil, nuclear, hydro and renewables (The Coal Resource). Coal has a very long and varied history. Some historians believe that coal was first used commercially in China. There are reports that a mine in northeastern China provided coal for smelting copper and for casting coins around 1000 BC. One of the earliest known references to coal was made by the Greek philosopher and scientist Aristotle, who referred to a charcoal like rock. Coal cinders found among Roman ruins in England indicate that the Romans used energy from coal before AD 400. Chronicles from the Middle Ages provide the first evidence of coal mining in Europe and even of an international trade as sea coal from exposed coal seams on the English coast was gathered and exported to Belgium. (The Coal Resource). Coal ha s played this significant role for centuries –