C1aL19 Reducing Sulphur Problems
Key Words
Acid rain - rain that has reacted with sulphur dioxide to form an acidic solution
Coal - a sedimentary rock formed by compressing plant material. Used as a fuel.
Environment - our surroundings, and the things that live there.
Fossil fuels - fuels derived from living things that caught the sun's energy millions of years ago.
Hydrogen sulphide - H2S, a poisonous and foul-smelling gas, stinking of rotten eggs.
Natural Gas - methane.
Oil - crude oil, a foul sticky liquid from which petroleum products are made.
Resource - supply of fuel.
Scrubber - device that removes sulphur dioxide from waste gases.
Sulphur compounds - compounds of sulphur (really?).
Sulphur Dioxide - SO2, a toxic and irritating gas given off when coal is burned.
Grade E
Fossil fuels are:
- Coal,
- Oil,
- Natural Gas.
In addition, most fossil fuels contain a certain amount of sulphur. This burns to form sulphur dioxide, SO2:
sulphur + oxygen ® sulphur dioxide
Both carbon dioxide and sulphur dioxide dissolve in water to make acid rain.
Sulphur can be removed from fuels to reduce the amount of sulphur dioxide. Or the sulphur dioxide can be removed from the waste gases.
Grade C
Sulphur in fuels is in the form of hydrogen sulphide (H2S), a poisonous gas that has the characteristic smell of rotten eggs. The hydrogen sulphide is dissolved in a solvent and the sulphur extracted.
In power stations, the sulphur dioxide is removed using equipment called a scrubber. A mixture of limestone and water is injected and the sulphur dioxide reacts with the calcium carbonate to form calcium sulphate or gypsum.
Grade A
While acid rain is generally experienced downwind (mostly to the East) of polluters, it has also been observed in the West. It is thought that the pollution comes from ships. Marine diesel engines are huge machines, dwarfing even the huge engines found in railway locomotives. They use huge amounts of fuel oil, and shipping in the Atlantic Ocean is thought to be contributing to acid rain in the West.