Coal and Petroleum Test - 9

When dead plants and animals get buried deep under the earth, they get decomposed by the action of anaerobic bacteria. Hydrogen and oxygen escape as gases leaving behind carbon. As years pass, layers of carbon atoms are added one above the other forming a stony substance called coal, this process is called carbonization.

Coal is of four different varieties: peat, lignite, bituminous and anthracite. Among these, peat is the low grade quality coal. It is formed during the starting stage of coal formation. It has the lowest percentage of carbon around 10%-20%.

Anthracite is a fine quality coal. It contains the highest percentage of carbon. It contains 94-98% carbon.

As oxygen is a supporter of combustion, fuels burn in oxygen to produce heat and light.

Natural gas is a mixture of methane, ethane, propane, butane, carbon dioxide, nitrogen and oxygen. But methane CH₄ constitutes a major percentage of about 85.

Gobar gas (produced by the decomposition of animal dung, domestic and agricultural waste in the presence of anaerobic bacteria) contains methane in bulk (50-68%) and other gases in relatively low proportions, i.e. CO₂(25−35

Generally, gases are liquified by applying high pressure (or) low temperature. In LPG cylinders especially, the gas is liquified by applying high pressure and it is stored in cylinders.

In fractional distillation of petroleum, the vapours with the highest boiling point cannot move up in the fractionating column, (as they have low vapour pressure). So, the liquids with high boiling points condense in the lowest (tray) portion of the fractionating tower.

Kerosene oil is more suitable than petrol in oil lamps because kerosene oil is less volatile than petrol. It costs less and is easy to handle.

Kerosene is mainly gused as a fuel in jet engines.