Environmental Problems

Environmental Problems

1. Gases and Particles

   • Power Stations burn a lot of fossil fuels to make electicity
   • Cars are also a major culprit in burning fossil fuels
   • Most fuels such as crude oil and coal contain hydrogen and carbon.
     • During combustion the carbon and hydrogen are oxidised so that carbon dioxide and water vapour are released into the atmosphere. Energy (heat) is also produced.
       • hydrocarbon + oxygen ---> carbon dioxide + water vapour
       • If the fuel contains sulphur impurities, the sulfur will be released as sulfur dioxide when the fuel is burnt.
       • Oxides of nitrogen will also form if the fuel is burnt at a high temprature
       • When there's plenty of oxygen, all the fuel burns, this is called complete combustion
         • If there isn't enough oxygen, some of the fuel doesn't burn. This is called partial combustion
           • Under these conditions, solid particles (particulates) of soot (carbon) and unburnt fuel are released. Carbon Monoxide is also released (poisonous)

2. Acid Rain

   • Sulfur dioxide is one of the gases which causes acid rain.
     • When the sulfur mixes with clouds it forms dilute sulfuric acid. This then falls as acid rain.
       • In the same way, oxides of nitrogen cause acid rain by forming with clouds.
   • Negative Effects
     • Acid rain causes lakes to become acidic and many plants and animals die as a result
     • Acid Rain kills trees and damages limestone buildings and ruins stone statues
     • Links between human health and acid rain have been suggested
     • Governments have recognized the environmental impacts and agreements have been put in place to reduce the sulfur dioxide emissions
   • Reducing Acid Rain
     • Most of the sulfur can be removed from fuels before they're burnt, but it costs more to do it
     • Also removing sulfur from fuels takes more energy. This is usually comes from burning more fuel, which releases more of the greenhouse gas carbon dioxide
     • However, petrol and diesel are starting to be replaced by low-sulfur versions.
     • Power stations now have acid gas scrubbers to take out harmful gases out before they release into the atmosphere.
     • The other way to reduce acid rain is to simply reduce our burning of fossil fuels.