• Carbon dioxide gas is pumped through the reactor to take the heat away, and the hot gas then heats water to make steam. • The steam drives turbines which drive generators. Modern nuclear power stations use the same type of turbines and generators as conventional power stations.
Petroleum (/)
How is petroleum used?
• The thick crude oil that comes from the ground is a complex mixture of compounds. It is necessary to separate the compounds. The separated substances have two main uses:
World Fuel Resources
Petroleum or Oil Power reserves Total used in 1990 130 billion tonnes 2.2 billion tonnes Natural Gas 158 billion cubic metres 1.5billion cubic metres Coal 950 billion tonnes 2.2 billion tonnes
•
Non-Renewable energy sources:
2.Nuclear Energy
What are Nuclear Power?
• Nuclear power is generated using Uranium, which is a metal mined in various parts of the world. Some military ships and submarines have nuclear power plants for engines. • Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels
From the above table, the present world's estimated oil reserves may be used up in the next 50 to 60 years.
Coal
• Coal is the plants ,that grew in swampy areas about 300 millions ago, died to form layers of decaying material. • Heat, pressure and the action of bacteria changed the decaying plants into coal.
Integrated Science Renewable and Nonrenewable energy sources
Introduction of sources of energy
Non-Renewable
1. Fossil Fuels 2. Nuclear
Renewable
1. 2. 3. 4. 5. Wind Solar Tidal Hydropower Geothermal
Disadvantages
• Pollution Burning any fossil fuel produces carbon dioxide, which contributes to the "greenhouse effect", warming the Earth. Burning coal produces more carbon dioxide than burning oil or gas. It also produces sulphur dioxide, a gas that contributes to acid rain. We can reduce this before releasing the waste gases into the atmosphere. Mining coal can be difficult and dangerous. • Strip mining destroys large areas of the landscape.
Petroleum
1. How was petroleum formed?
• Petroleum was formed from small sea animals and plants that lived millions of years ago. After they died, heat; pressure; and the action of bacteria changed the remains into oil. The oil formed was then trapped as small drops inside the pores of rocks.
Disadvantages
• It is very, very dangerous. • It must be sealed up and buried for many years to allow the radioactivity to die away. • It is reliable, but a lot of money has to be spent on safety - if it does go wrong, a nuclear accident can be a major disaster. People are increasingly concerned about the safety.
Advantages
• Nuclear power costs about the same as coal, so it's not expensive to make. • Does not produce smoke or carbon dioxide, so it does not contribute to the greenhouse effect. • Produces huge amounts of energy from small amounts of fuel. • Produces small amounts of waste.
•
Natural Gas
• Natural gas is found together with oil and sometimes with coal. • The gas consists mainly of methane CH4.
Natural Gas (/)
• The major fossil fuels are – coal (煤), – petroleum (石油) and – natural gas (天然氣).
• Fossils fuels are non-renewable (非再生能 源) energy sources. • This is because fossil fuels take millions of years to form. Once they are used up they can never be replaced.
How it works
• Nuclear power stations work in pretty much the same way as fossil fuel-burning stations, except that a "chain reaction" inside a nuclear reactor makes the heat instead. • ቤተ መጻሕፍቲ ባይዱhe reactor uses Uranium rods as fuel, and the heat is generated by nuclear fission. Neutrons smash into the nucleus of the uranium atoms, which split roughly in half and release energy in the form of heat.
• In some countries, the gas is carried by pipes to homes and factories for heating and cooking.
HOW NATURAL GAS IS STORED AND DELIVERED
How is petroleum used?
Non-Renewable energy sources: 1.Fossil Fuels
What are fossil fuels ?
• A fuel is any substance used as a source of energy, including heating, transport, electricity generation and other uses. • Most of the world’s energy is provided by the burning of fossil fuels (化石燃料). • Coal, Oil and Gas are called "fossil fuels”because they are natural combustible substances formed originally from dead plants and animals.