Environmental Engineering Reference
In-Depth Information
Table 6.6
Sources of natural gas imports for the United States
Country
Percentage
Canada
82.1
Trinidad
9.7
Egypt
2.5
Nigeria
2.1
Algeria
1.7
Others
1.9
TOTAL
100.0
Source:
Energy Information Administration (2008).
Countries Forum, meets each year and will probably formally declare its
solidarity in the near future. Many of the nations in the forum are the
same ones that belong to OPEC—Iran, Qatar, United Arab Emirates,
Nigeria, Algeria, and Venezuela. It is not a group that the United States
would like to depend on for an essential resource.
America's natural gas imports are mostly from Canada and are deliv-
ered by pipeline (table 6.6). In part, the dominance of Canadian imports
refl ects a desire to avoid sources in the volatile Middle East. But mostly
it refl ects the fact that shipping gas by tanker ship across the ocean is a
complicated and expensive process. To permit large amounts of natural
gas to be transported across the ocean requires liquefying it. Liquefaction
converts gas at room temperature to 1/600 of its original volume. Natural
gas liquefi es at −258°F. It must be cooled at the shipping terminal,
pumped into heavily insulated cargo holds, and then heated as it is dis-
charged at the receiving terminal. New receiving terminals for liquefi ed
natural gas (LNG) are being built along America's coastline as fast as
possible because of our soaring rate of imports. As of February 2009,
nine terminals were in operation, 7 more were under construction,
sixteen more were federally approved but not yet under construction,
and nine more were proposed.
17
In early 2007, less than 10 percent of
global natural gas production was transported as LNG.
Unconventional Sources of Natural Gas
Production of natural gas in the United States from conventional sources
(subsurface wells) has been declining for a number of years, but our
domestic supply has been fairly level because production of gas from
unconventional sources has been rising. It now supplies more than 40
