Environmental Impact from fossil fuels

previous Energy conversion

Coal, Oil and Natural gas have their relative merits in terms of availability, price and thermal performance. Table 1.3 below is constructed for comparison of the heat capacity, CO₂ and SO₂ production by the three fossil fuels. The 4th column is of particular importance in comparing all three fuels; it represents the quantity of carbon dioxide emitted for every unit of energy produced.

Coal produces the highest amount of Carbon dioxide for a given output of energy; then oil, then Natural gas which produces nearly half the emission of coal and a third less than that of oil.

The results displayed in table 1.3 for the production of CO₂ mass per unit energy compares well with data published by the UK government, Action on Energy, the values found in this chapter are lower than those quoted in the reference, the difference is that the calculations shown in this chapter were only concerned with the combustion process itself; there other knock on effect in the calculations when the life cycle of the fuel is considered, hence the addition of energy used to transport, process the fuel, and to include distribution losses.

Fuel	Calorific Value MJ/kg	CO₂ kg / kg fuel	CO₂ / Energy kg / MJ	SO₂ kg / kg fuel
Coal	26	2.361	0.091	0.018
Oil	42	3.153	0.075	0.040
Natural Gas	55	2.750	0.050	0

Table 1.3 Environmental impacts of fossil fuels

Energy world-wide

The consumption of energy by humankind has evolved over the ages. It began with the invention of fire, man relied on wood burning to cook and to provide warmth and light for millions of years. As civilization evolved, the needs for energy became greater and other sources were sought. In the long search, man discovered coal. Over the years coal provided much greater resource for energy, encouraging man to push its use into further applications.

A major leap in the nineteenth century was achieved by the discovery of oil in the Middle East. This unfortunate discovery eventually led to TWO World wars as the leading industrial nations attempted to dominate the world market and to secure the energy supply for their huge manufacturing industries. The oil crises due to the Arab-Israeli war in 1973 resulted in tripling of oil prices, this was a major shock for non producing countries, particularly in Europe, on one hand it has put tremendous increase on the energy consumer’s budget;

The discovery of oil pushed the competition for manufacturing beyond the industrialized countries own borders. This competition for shares in the exports market put so much strain on the consumption of fossil fuel. Hubbert put foreword his caution when he published his famous curve (1956), Figure 1.2. It is clear that the oil reserves of the world are consumed unsustainably and will be exhausted within this century. Humans have to find a new source or sources of energy to replace oil.

However, on the positive side, the depletion of oil can be considered as a major advantage to humankind and the environment, it will force consumers to reduce the excessive consumption of energy, it will help man to review manufacturing processes and attempt to increase energy efficiency, and probably it has already pushed governments to search for newer sources of energy. Substantial funds are allocated for the research into renewable resources such as Hydropower, wind turbines and solar energy.

Energy consumption world-wide has continued to rise, it is estimated that in 1900, the world consumption was around 22 EJ and by 1960 it rose to 128 EJ; this reached 564 EJ in 2000.

The continued increase in population and the associated increase in manufacturing industry to cater for greater dependence of man on energy driven devices and the culture of multi-car ownership has put even greater importance for energy. It is interesting to note that the energy consumption for individuals have increased by 10 folds over the century mentioned above. This is another proof that we are becoming too excessive and becoming too dependant on energy far greater than we did before.