chem- chap: fossil fuels

fossil fuels

main sources of energy used to generate electricity, some modes of transport are powered directly by fossil fuels, some powered electricity

fossil are known as hydrocarbons

hydrocarbons consist of hydrogen and carbon only

• formed from the decomposition of plants (charcoal) and animals (natural + crude oil) that lived millions of years ago

natural gas is a gaseous fossil fuel containing mainly methane (CH4)

eqn: methane + oxygen → carbon dioxide + water

CH4(g)2O2(g) → CO2(g) +2H2O(g)

before natural gas get transported

undergoes process called liquefaction to produce LNG (liquified natural gas )

LNG is safer for consumers

compared to the gaseous form of natural gas as it does not burn too easily

crude oil ( aka petroleum) is a mixture of hydrocarbons

these hydrocarbons have different properties, they can be separated into different groups of hydrocarbons before each group can be used

crude oil and natural gas are common forms of fossil fuels

they are considered as non-renewable sources of energy,

• thre are limited quantities of crude oil and natrual gas

• they cannot be replaced fast enough for our rate of use

when fossil fuels are burnt in the presence of oxygen

the main products formed are carbon dioxide and water, this process is known as combustion and generates thermal energy