Environmental Engineering Reference
In-Depth Information
geria)—imposed an embargo on oil exports to the countries supporting Israel. As a
result, oil prices increased 400 percent in 6 months. This was compounded in 1979
with events in Iran and the war with Iraq, which led to another round of crude oil
price increases.
Figure 4.1 The evolution of the price of oil
Prices fell off dramatically in the 1980s, to historical levels, but has more re-
cently increased to almost US$100 per barrel, due to upheavals in the Middle East,
particularly Iraq and Libya (the main sources of the oil used in the US, Europe, and
Japan).
Figure 4.1
charts this evolution in the price of oil in nominal and constant
2009 dollars.
Like oil, gas is trapped in porous underground rock formations, predominantly
composed of sandstone. Its chief combustible component is methane (CH
4
). Other
energy-relevant components of natural gas include butane, ethane, and propane.
