Petroleum is a fossil fuel that naturally occurs in the liquid form created by the decomposition of organic matter beneath the surface of the earth millions of years ago. These fossil fuels are then refined into usable substances such as petrol, kerosene etc. It is formed by the combination of hydrocarbons and other substances, mainly sulphur. When first collected in its natural form, it is termed as crude oil.
When petroleum is heated in the refinery petrol will be isolated at the temperature of 35-70°C.