Cummins Westport Inc. - Alternative Fuels

Alternative Fuels - Liquefied Natural Gas

What is Liquefied Natural Gas (LNG)?

Refueling of a typical Liquefied Natural Gas (LNG) storage tank.

Natural gas is liquefied by cooling it to -160 Celsius (-260 F) at atmospheric pressure. Why bother? Because 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 about 4% 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.

Cummins Westport engines can accept a wide range of natural gas fuel compositions. Use our Fuel Performance Specification Calculator to ensure compatibility.

What is Natural Gas?

World Energy Consumption. Natural gas provides almost one-fourth of the world's energy needs. (source: BP Statistical Review of World Energy 2007, BP p.l.c.)

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 molecule of carbon and four molecules 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.

For more information on alternative fuels, visit our Alternative Fuels Links page.

ALTERNATIVE FUELS

Compressed Natural Gas
Liquefied Natural Gas
Liquid Propane Gas
Hydrogen-Enriched CNG
Biomethane
Fuel Specifications
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