Natural
gas is liquefied by cooling it to -160 °C (-260 °F) at atmospheric pressure. At that temperature, LNG occupies 1/600th
the volume of natural gas at atmospheric temperature and pressure. The high energy density of LNG makes it useful for energy
storage in double-walled, vacuum-insulated tanks.
LNG accounts for an increasing amount of natural gas consumption worldwide, and is produced in dozens of large-scale liquefaction
plants. These are operated by distribution utilities for seasonal storage, and by companies that ship natural gas by tanker
across oceans.
Because LNG is a relatively new fuel for trucking, many existing liquefaction plants aren't designed to serve the needs of
truckers and aren't located in places convenient for truck refueling. As LNG becomes more widely used for vehicles, production
facilities will change to accommodate this economic activity.
Data from the Department of Energy Alternative Fuels Data
Center provides information about the location of LNG refueling stations in the U.S. Cummins Westport expects that the
initial users of LNG trucks will be fleets whose vehicles return to the fleet yard at night for refueling. Over time, as more
facilities become available on public highways, long range truck operators may also consider using LNG.
Natural
gas was formed from the buried remains of tiny plants and sea animals that died more than 200 million years ago. Under the pressure and heat of
built-up sand and silt—sometimes thousands of feet thick—these energy-rich materials slowly decayed, then changed form until all that
was left were concentrations of natural gas in layers of rock.
Natural gas is removed from the earth by drilling wells into the rock, then using pipes to bring the gas to the surface. In most wells, the
pressure of the natural gas is enough to force it to the surface and into the gathering lines that run to central collection points.
Natural gas has a simple chemical make-up: one atom of carbon and four atoms of hydrogen (CH4). That's what makes
it burn so cleanly. Oil and coal, the other fossil fuels, are more chemically complex. They contain higher proportions of carbon, sulphur and
nitrogen.
Currently, natural gas supplies one-fourth of the energy needed to efficiently run the world's homes, businesses, vehicles, industries and
power plants. Over the next 20 years, consumption of natural gas is expected to grow by 50 percent.
According to the Gas Vehicle Report,
there are more than 10 million natural gas vehicles on the road around the world today and over 15,000 refueling stations.
Natural
gas was formed from the buried remains of tiny plants and sea animals that died more than 200 million years ago. Under the pressure and heat of
built-up sand and silt—sometimes thousands of feet thick—these energy-rich materials slowly decayed, then changed form until all that
was left were concentrations of natural gas in layers of rock.