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►Fossil Fuels:
Fossil fuels are fuels that result
from the fossilization process of living tissue after millions of years.
Fossil fuels, chiefly coal, oil and natural gas, now supply most of the
world's energy. Only a small amount comes from renewable sources.
By the year 2050, renewable sources could provide forty percent of the
energy needed in the world. Use of renewable energy can help both to
slow global warming and to reduce air pollution. These fossil fuels,
coal, oil, and natural gas also emit greenhouse gases when burned. The
world may be supplied with enough coal to last over 100 years The
world's oil supply is also estimated to last over 100 years. Natural Gas
supplies are projected to last over 100 years.
Percentage of CO2 comes from Oil, Natural Gas,
and Coal
Coal |
Natural Gas |
OIL |
Country (region) |
36.90% |
18.40% |
44.70% |
World |
18.20% |
30% |
51.80% |
Canada |
33.70% |
21.30% |
45% |
United States |
24.80% |
19% |
56.20% |
European Union |
81.50% |
1.10% |
17.40% |
China |
25.50% |
9.90% |
64.60% |
Japan |
Coal:
Evolutionary Stages of Coal
Development:
Coal comes in several developmental
stages, peat, lignite, bituminous and anthracite forms of coal.
The first two stages are very inefficient producing a small amount of
energy per mass of fuel. Lignite can be gasified to natural gas which is
a particularly clean burning fuel in itself.
Lignite has also been liquefied to produce liquid petroleum fractions.
But the gasification and liquefaction process are very expensive and are
not cost effective unless the cost of crude petroleum reaches 60.00 a
barrel or more.
Bituminous (soft coal) and Anthracite (hard coal) are the stages of coal
most often mined, processed , and used as fuel.
The extraction of the coal from the ground can be very expensive. Most
coal deposits lie well below the surface of the earth.
When carbon reacts with the oxygen in the air, carbon dioxide and carbon
monoxide are produced.
C + O2 ----> CO2(g)
and
C + 1/2 O2 ----> CO(g)
The CO2 is the major product of
combustion and is of itself not particularly harmful. Carbon Monoxide,
CO, is an insidious toxic gas. Its toxicity lies in the fact that CO can
bind to hemoglobin in the blood thus depriving life giving Oxygen of its
vehicle to reach the cells. It also deprives waste gas, CO2, of the
hemoglobin so that evacuation of waste gases is not possible.
Just 50 parts per million of CO in the air can cause dizziness, nausea,
and irritability.
A thousand parts per million can result in loss of consciousness. 10,000
parts per million can result in death within 10 minutes. .
Coal that has sulfur impurities will cause the sulfur to undergo
combustion:
S + O2 ----> SO2
and
2S + 3O2 ----> SO3
Crude Petroleum :
Crude petroleum is a complex mixture
of hydrocarbons resulting in a mixture that has dissolved gases. Crude
petroleum is not particularly useful in its natural state. Crude
petroleum has to be processed before it can be used efficiently. This
refining process involves fractional distillation which yields fractions
of the petroleum such as natural gas, gasoline, kerosene, diesel, light
oils
(low viscosity), heavy oils (high viscosity), and waxes (solid
hydrocarbons). Other refining processes can be done to improve the
burning efficiency (monitored as octane rating), Catalytic cracking
processes, polymerization processes and others can add to the burning
efficiency of the various fractions like gasoline.
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