L8: Reducing pollution Flashcards
What are some ways of reducing pollution?
Catalytic converters, low sulphur petrol and wet scrubbing
Where are catalytic converters used?
In car engines
Why are catalytic converters used?
To stop the release of carbon monoxide (sometimes there is not enough oxygen) and nitrogen oxides into the athmosphere
What is the reaction taking place in the catalytic converter?
carbon monoxide + nitrogen oxide -> carbon dioxide and nitrogen
Why are catalytic converters useful?
Because carbon dioxide is less harmful than carbon monoxide and nitrogen is not harmful
How does the use of low sulphur petrol help pollution?
Because sulphur dioxide causes acid rain, harming the environment
What is reduced in a catalytic converter?
Nitrogen oxide to nitrogen
What is oxidised in a catalytic converter?
Carbon monoxide to carbon dioxide
Where is wet scrubbing (gas scrubbing) used?
In factories because that is where fuel is burned
Where do the waste gases pass through in a factory?
A wet scrubber
What is sprayed on the waste gases?
An alkaline slurry of lime (calcium hydroxide) and water
What does the spray react with?
Sulphur dioxide
What is the product formed in the wet scrubber?
Calcium sulphate
How is calcium sulphate used?
It is sometimes sold as building plaster
What other liquid can be used to spray the waste gases?
seawater
