Alternatives to Petroleum
In 2008, the top 15 oil consuming nations used nearly 60 million barrels of oil per day. The United States accounted for roughly 19,500,000 of that, followed by China at 7,831,000. The world’s top oil producers in 2006, measured by barrels produced per day, were Saudi Arabia, Russia, and the United States.
It is estimated that peak oil either has been reached, in 2006, or will be reached by 2020. Peak oil is the point when extraction of crude becomes increasingly more difficult and costly. The result is high energy costs for everything from home heating to transportation. Roughly 90% of all vehicles in the world run on oil-derived products. This accounts for roughly 70% of all petroleum used. In the United States, petroleum constitutes 40% of the nation’s total energy use, most of which goes to the transportation industry. As fuel costs continue to rise, the infrastructure of modern society is being threatened Alternatives to the use of fossil fuels in general, and petroleum in particular, have been sought for many reasons including the limited supply of readily accessible reserves, national security, environmental impact, and profit.
As the primary use of petroleum is for transportation, replacing its use in that setting has been the target of most investigations. The transportation industry accounts for 14% of greenhouse gas emissions and is exceeded only by industrial processes and electrical generation that rely upon coal. The retrieval, processing, and distribution of fossil fuels accounts for another 11.3% of greenhouse gas emissions. Alternatives to petroleum have included alcohol, solar, wind, hydrogen, and biofuels.
The following table illustrates the energy densities of common fuels. When energy is standardized by energy density, the amount of energy in a given volume, it is easier to compare.
|
Item |
Energy per Kilogram |
Energy Per Liter |
|
Gasoline |
47.2 megajoules |
34 megajoules |
|
Diesel |
45.4 megajoules |
38.6 megajoules |
|
Hydrogen |
143 megajoules |
5.6 megajoules |
|
Uranium |
20 terajoules |
N/A |
|
Coal |
24 megajoules |
20 megajoules |
|
Lithium-ion battery |
720 kilojoules |
N/A |
|
Gasohol (E10) |
43 megajoules |
33.18 megajoules |
|
Gasohol (E85) |
33.1 megajoules |
25.6 megajoules |
|
Biodiesel |
42 megajoules |
33 megajoules |
|
Ethanol |
30 megajoules |
24 megajoules |
|
|
|
|
|
Joule = The
amount of energy expended in applying a force of one newton over a distance
of one meter. By example, one joule is the approximate amount of energy
required to lift a small apple one meter off of the ground. For a 1000 kg car
to acceleration from 0 to 100 km/hr requires approximately 365 kilojoules.
That would require 10 mL of gasoline or 67 mL of hydrogen from the above
table. |
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