4b

Mixture of hydrocarbons

• It is heated, vaporised in a fractional distillation tower (hotter at the bottom, cooler at the top) • Gases travel until the temperature is lower than the boiling point, then they turn into a liquid (except natural gases, which stay as gases and bitumen that comes off at the bottom and never turns into a gas) The boiling point and viscosity decrease as you go down Flammability increases as you go up

• Natural gases • Petrol / Gasoline • Kerosine • Diesel • Fuel oil • Bitumen

Home heating

Car fuel

Plane fuel

Bus/Lorrie fuel

Boat/Power station fuel

Roads

A substance that releases energy when burnt

• In car engines • If the temperature is high enough, Nitrogen in the air reacts with oxygen to form nitrogen oxygen

• Fuels can contain impurities such as sulfur • When these impure fuels are burnt, sulfur dioxide is produced

Spliting larger alkanes(less value) into smaller alkanes(more value) and alkenes (and/or hydrogen) Requires: Heat(600-700 ºC), Catalyst(silica or alumina) Longer alkane –> Shorter Alkane + Alkene

• Produces smaller, more valuable in demand hydrocarbons. • Less demand for longer alkanes • That are used for fuels or polymers