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Depending on the grade, coal is mostly carbon and is therefore a
major contributor to greenhouse gas emissions. For the unit energy
obtained, it is the most polluting fossil fuel. It is also rich in other
major pollutants, such as sulfur, mercury, radioactive elements etc.
It is derived from vegetable matter which has become partially or totally
petrified by pressure, heat and chemical changes. Coal is found in many
countries throughout the world, although it is not always exploited.
Composition
This section is an edited excerpt
from Wikipedia[1]
The table is a classification of different coal types,
according to German sources. The nomenclature may vary from
country to country.
| Name |
Volatiles % |
C Carbon % |
H Hydrogen % |
O Oxygen % |
S Sulfur % |
Heat content kJ/kg |
Bituminous |
| Lignite |
45-65 |
60-75 |
6.0-5.8 |
34-17 |
0.5-3 |
<28470 |
No |
| Flame coal |
40-45 |
75-82 |
6.0-5.8 |
>9.8 |
~1 |
<32870 |
Yes |
| Gas flame coal |
35-40 |
82-85 |
5.8-5.6 |
9.8-7.3 |
~1 |
<33910 |
Yes |
| Gas coal |
28-35 |
85-87.5 |
5.6-5.0 |
7.3-4.5 |
~1 |
<34960 |
Yes |
| Fat coal |
19-28 |
87.5-89.5 |
5.0-4.5 |
4.5-3.2 |
~1 |
<35380 |
Yes |
| Forge coal |
14-19 |
89.5-90.5 |
4.5-4.0 |
3.2-2.8 |
~1 |
<35380 |
Yes |
| Non baking coal |
10-14 |
90.5-91.5 |
4.0-3.75 |
2.8-3.5 |
~1 |
<35380 |
Yes |
| Anthracite |
7-12 |
>91.5 |
<3.75 |
<2.5 |
~1 |
<35300 |
No |
Use of coal
About 4.6 billion tonnes of coal are used annually for the
generation of electricity, especially in the USA, China and
India. Another 1.6 million tonnes are used for other industrial
purposes, such as in the metallurgical industries, coking and
coal gas generation, plus domestic use. It is widespreadly used
in China for cooking.
Environment
For further details on the effects on the environment, see
also
Energy safety.
The following information is an
edited excerpt from Wikipedia
There are a number of adverse environmental effects of coal
mining and burning.
These effects include:
- release of
carbon dioxide and
methane, both of which are
greenhouse gases, which are causing
climate change, according to the
IPCC. Coal is the largest contributor to the human-made
increase of CO2 in the air.
- waste products including
heavy metals and
radionuclides of uranium, thorium, radon etc.
- vast quantities of sterile ash and fly ash to dispose of
-
acid rain
- interference with groundwater and water table levels
- impact of water use on flows of rivers and consequential
impact on other land-uses
- dust nuisance
- subsidence above tunnels, sometimes damaging
infrastructure
- rendering land unfit for other uses.
- coal-fired power plants without effective fly ash
capture are one of the largest sources of human-caused
background radiation exposure.
- vast quantities of
aerosols affecting the earth's
albedo
Human H&S
The following is quoted directly from the
EEWiki article on
Energy safety.
It is impossible to obtain reliable data on deaths related to mining
the coal, transporting it, burning it and being affected by the
pollution that is produced. It is estimated that between 5 000 and 10
000 are killed in mine accidents each year, on average. On top of that,
at least double this figure die from pneumoconiosis. Assuming that half
the coal mined is used to generating electricity, this means that 20 000
people, as a minimum, die prematurely each year before the coal is even
burned to produce electricity.
It is possibly ironic that the country which suffered the worst
nuclear disaster is also one of the countries with the worst statistics
for mining accidents, in terms of the quantity of coal mined. Ukraine
has consistently suffered from various types of mining accident over the
years.
The following quotation from the
Earth Policy Institute (© 2004, with
tacit permission) illustrates the effects of pollution from coal burning
plant in the USA.
In the United States, 23,600 deaths each year can be attributed to
air pollution from power plants. Those dying prematurely due to
exposure to particulate matter lose, on average, 14 years of life.
Burning coal also is responsible for some 554,000 asthma attacks,
16,200 cases of chronic bronchitis, and 38,200 non-fatal heart
attacks each year. Atmospheric power plant pollution in the United
States racks up an estimated annual health care bill of over $160
billion.
Other figures quote
an annual death toll of 400 000 in China.
It is difficult to find corresponding figures for India and other
countries. It nevertheless seems probable, even using the most
conservative data, that the number of persons dying prematurely each
year from coal-burning electricity generation must be in the hundreds of
thousands (and not necessarily in the countries which produce the
pollution!
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