Pollution from cars: production and effects of pollutants

Production:

• Evaporative emissions and incomplete combustion

Effects:

• Contributes to formation of photochemical smog, causing respiratory problems

Way to reduce pollutant:

• Reduced by catalytic converters and oxygenates, but this means CO2 is increased

Production:

• Incomplete combustion of hydrocarbons

Effects:

• Toxic to humans as it decreases the uptake of oxygen by the blood

Way to reduce pollutant:

• Reduced by catalytic converters and oxygenates, but this means CO2 is increased
• Reduced in lean burn engines, but this may mean CxHy is increased

Production:

• Complete combustion of hydrocarbons

Effects:

• Causes the greenhouse effect and global warming

Way to reduce pollutant:

• Hydrogen is the only petrol alternative which doesn't produce CO2

Production:

• Nitrogen from the air reacts with oxygen from the air in the high temperatures of the engine

Effects:

• Contributes to the formation of photochemical smog, causing respiratory problems
• Causes acid rain

Way to reduce pollutant:

• Reduced by catalytic converters but this means that CO2 is increased
• Reduced in lean burn engines, but this may mean CxHy is increased

Production:

• Sulphur in petrol reacts with oxygen in the air in the heat of the engine

Effects:

• Causes acid rain which erodes limestone buildings and damages forests and lakes

Way to reduce pollutant:

• Low sulphur petrol can be produced by desulphurisation