Alkanes as Fuels

Carbon Monoxide is formed if alkanes burn incompletely

• Carbon monoxide is poisonous - molecules bind to same sites on haemoglobin molecules in red blood cells as oxygen molecules meaning oxygen can't be carried around the body.
• Can be removed from exhaust gases by catalytic converters.
• Oxygenates are added to petrol to reduce carbon monoxide emissions - they help the fuel to combust fully

Unburnt hydrocarbons and oxides of nitrogen contribute to smog

• Engines don't burn all the fuel molecules - some come out as unburnt hydrocarbons
• Oxides of nitrogen are produced when the high pressure and temperature in a car engine cause the nitrogen and oxygens atoms in the air to react together
• The hydrocarbons and nitrogen oxides react in the presence of sunlight to form ground level ozone - a major component of smog
• Low level ozone irritates eyes, aggrivates respiratory problems and causes lung damage
• Catalytic converters on cars remove unburnt hydrocarbons and oxides of nitrogen from the exhaust

Sulphur Dioxide

• Burning fossil fuels which contain sulphur causes acid rain
• Sulphur burns to produce sulphur dioxide gas which enters the atmosphere, dissolves in the moisture and is converted into sulphuric acid
• Acid rain destroys trees, vegetation, buildings, statues and fish in lakes
• Can be removed using calcium oxide which is basic

Carbon Footprint - tells you how much effect something has on the environment

Carbon Neutral - carbon neutral activities have no overall carbon emission into the atmosphere

Bioethanol is pretty much carbon neutral

• produced by fermentation of sugar from crops like Maize
• all the carbon dioxide released when the fuel is burned was removed by the plant as it grew
• still carbon emissons if you consider whole process - making fertilisers and powering agricultural machinery will involve burning fossil fuels