Coal does have a future, and China is planning to build six hundred coal-fired power stations over the next twenty years.
Global warming is a global problem, and any global solution must involve China. The way forward is not for Britain, Europe and the United States and other countries to tell China not to build coal-fired power stations but for them to demonstrate to her that clean zero carbon coal-fired power stations are technically and commercially viable, and Britain has a major part to play in this, as both Greenpeace and Friends of the Earth acknowledge. For Britain unilaterally to adopt an energy policy based on “Wind Good Coal Bad” would be economically catastrophic for Britain while having no impact at all upon that is happening in America and China, which is where the Planet can be saved.
Coal is impure carbon, formed from plants that grew on land and in swamps. The stages in its formation are
Peat bogs are very important wildlife habitats for a large number of plants and animals and other organisms. Peat is used as a fuel in rural parts of Scotland and Ireland, and also in other parts of the World, but as a fuel it is mostly cut by local people to meet a local need. Although peat produces carbon dioxide when it is burnt the alternative to peat would usually be other fossil fuels which would need to be transported into the area by truck so producing even more carbon dioxide. The real danger to the World's peat bogs comes not from cutting peat for fuel but digging them up to make peat-based composts for sale in garden centres, draining them to turn into farmland, and acid rain and other pollution which kills the mosses and other plants whose roots bind the peat together and prevent it from being eroded by wind and rain. Draining them is environmentally catastrophic because, apart from the destruction of an irreplaceable wildlife habitat, they store vast quantities of carbon dioxide which is released back into the atmosphere as the peat dries out.
Lignite is widely used in power stations but is seldom used for any other purpose; bituminous coal and anthracite are used in power stations and for many other purposes; graphite has many uses, including of course in “lead” pencils, but is not used as a fuel because although it is practically pure carbon the way the carbon atoms in it are arranged makes it very difficult to burn. Coal by itself usually means bituminous coal although sometimes includes lignite and anthracite.
Coal has been burnt as a fuel for hundreds of years. The Industrial Revolution was fuelled by coal, the first railways were built to carry coal, for more than a hundred and fifty years the World’s railways were powered by coal, and today coal provides most of the World’s electricity.
Burning coal produces carbon dioxide, and the smoke from it also contains many other substances including sulphur dioxide , cadmium, mercury and carcinogenic tars. Until about sixty years ago most air pollution came from burning coal. In the 1950s more people died in London from air pollution than had been killed in air raids during the Second World War. Since then many “smokeless” fuels such as Coalite® have been produced and many different ways of removing most of the pollutants from power station waste gases have been developed, although most of today's coal-fired power stations still release their carbon dioxide into the atmosphere. Today however it is possible to build a totally clean coal-fired power station, in which all the carbon dioxide is safely buried and all the other pollutants removed.
The carbon dioxide from all fossil fuel (coal, gas and oil) power stations can be buried in old oil and gas fields: we can be certain that these do not leak because if they had leaked in the past the oil and gas would have escaped to the surface millions of years ago. The same method can be used for any fixed installation, but not unfortunately moving objects such as cars and aeroplanes.
There are two ways of building a carbon-free coal (or oil or gas) fired power station. The first is to build a conventional power station and bury the carbon dioxide after the fuel has been burnt; the second is to use the fuel to produce hydrogen. This process uses steam and produces carbon dioxide as well as hydrogen. In effect
Underground gasification of coal (UGC) is a very exciting way of converting coal into hydrogen without the need to dig it out of the ground. Boreholes carry the oxygen and steam into the coal seams and bring out the hydrogen, carbon dioxide and other gases. This technique can be used where mining (whether deep or opencast) is uneconomic, impractical or environmentally undesirable.
There are lots of other very exciting developments in this area taking place in Britain, particularly in Scotland and on Teeside, but the Government is being slow to make decisions about their future.
In the past, as well as producing lots of carbon dioxide and other pollutants, coal fired power stations have also been very inefficient, often converting less than 30% of the energy in the coal into electricity, but the efficiency of modern coal power stations is very much higher: in Denmark efficiencies of 90% are being achieved. It is also possible to use the low temperature waste heat from the cooling water to warm local buildings: this was being done at Battersea Power Station in the 1950s, but not again for another fifty years.
Oil and gas (more correctly, petroleum and the petroleum gases) are formed from the incomplete decomposition of tiny marine animals. They are mainly hydrocarbons, compounds of carbon and hydrogen. The ratio of gas to oil depends upon the temperature at which the decomposition took place: the higher the temperature the greater the proportion of gas. Because the deeper you go into the Earth’s crust the hotter it is, fields containing a high proportion of gas are, or at any rate were once, much deeper than those containing mainly oil.
Coal is very much more plentiful in the Earth’s crust than oil or gas. Many countries, including Russia and China, the United States, and Britain and most other European countries, have reserves of coal adequate for all their energy needs for several hundred years. However, many countries with large coal reserves have no, or almost no, reserves of oil or gas. In today’s economic and political climate any country with plenty of coal but no oil or gas might think it wise to develop an energy policy which does not require it to import more than 75% of its energy.
Almost everything we can get from oil and gas can also be made from coal, by a process called hydrogenation. In effect we use coal, oxygen and steam to make hydrogen and carbon dioxide, as above, and then use the hydrogen and more coal to make methane and other hydrocarbons. In 1933, before Adolf Hitler came to power, Germany was importing 85% of its oil, but Hitler introduced a massive hydrogenation programme and by 1944 Germany was obtaining 85% of its oil products such as petrol and diesel from coal. During the Second World War the Allies had not realised the importance of the hydrogenation plants to the German war effort until after the end of the War and as a result had not attempted to destroy them. South Africa has massive coal reserves but no oil or gas, and continued to develop hydrogenation after the Second World War in order to counter the oil sanctions imposed by the international community because of its Apartheid policies. The United States has coal reserves to meet all of its energy needs for more than a thousand years but currently obtains only 30% of its energy from coal. It is currently planning to make more use of hydrogenation of coal in order to reduce its dependence on imported oil.
Hydrogenation of coal produces carbon dioxide, and so does burning the fuels (methane, petrol, diesel etc) produced. If we wish not only to reduce our dependence on imported oil and gas but also to reduce our carbon dioxide emissions it would be better to use the coal to produce hydrogen, bury the carbon dioxide produced, and use the hydrogen as a fuel. There is more about this on the Hydrogen as a fuel page.
