Petrochemicals are hydrocarbons, obtained from naturally occurring raw materials viz. petroleum, natural gas, coal etc. Coal was initially the basic raw material for organic chemical industry. However the basic feedstock has changed recently from coal to petroleum. This is attributed to the recent innovation and technological advance in the field of chemical industry based on petroleum feedstock. The handling and processing cost of petroleum based raw materials to down-stream products are cheaper than that of based on coal even though the cost of coal is cheaper than the petroleum based feedstock.