Geology Reference
In-Depth Information
doubled between 2003 and 2009 to 110,000. That is a miniscule number, represent-
ing only 0.1 percent of all vehicles on the road, but it is growing.
The Dallas-Fort Worth Airport runs 500 maintenance vehicles on gas (and al-
lows hydrofracking beneath its runways). AT&T is buying 8,000 CNG-powered
vehicles, giving it the largest commercial NGV fleet in the country. School buses,
garbage trucks, and other municipal vehicles are switching.
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CNG is not ideal. It has to be stored at high pressure in bulky tanks. An average-
sized CNG tank provides only a quarter of the traveling distance of gasoline tanks.
Retrofitting vehicles with CNG equipment is costly, and refueling infrastructure
is not widely available. There are only 1,500 public CNG stations in the United
States, compared with 115,000 regular filling stations. Still, CNG is catching on
among fleet-delivery vehicles (FedEx and UPS trucks, for instance) and public
buses. Some 20 percent of local buses already run on CNG or LNG.
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Natural gas could also power ships. In an effort to save fuel and reduce emis-
sions, ferries in Argentina, Uruguay, Finland, and Sweden are already powered by
LNG. In 2014, a new LNG ferry will start plying the St. Lawrence River in Que-
bec. And in a New York City pilot project, one of the Staten Island ferries is being
retrofitted from a low-sulfur diesel to an LNG power plant; the switch will cut fuel
consumption in half and reduce greenhouse gas emissions by 25 percent. Such pilot
programs could lead to similar conversions on much bigger, oceangoing container
ships. The research firm IHS CERA projects that by 2030 a third of all cargo carri-
ers will be fueled by LNG.
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In Europe, regulators are pressuring shippers to reduce emissions, especially
on inland waterways. Royal Dutch Shell has chartered two LNG-powered tanker
barges to work on the Rhine River. The barges emit 25 percent less carbon dioxide
than their oil-burning competitors, and are quieter.
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Another way to fuel transport is through gas-to-liquids (GTL) technology,
which uses heat and chemistry to convert natural gas into liquid fuel (similar to the
way crude oil is converted into gasoline). The technology uses catalysts to turn gas
into longer-chained hydrocarbons, like diesel and kerosene, or various petrochem-
icals. There are now several GTL plants operating around the world. Shell's $19
billion Pearl facility in Qatar (jointly owned by the Qataris) is by far the largest,
and Shell may build a similar facility on the Gulf of Mexico.
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