The most common forms of natural gas are liquid and gas, but what you might not know is that a significant number of commercial vehicles utilize the gaseous form compressed to pressures above 3,100 pounds per square inch.
Compressed natural gas, or CNG, is what you get when gas is placed under pressure but remains clear, odorless and non-corrosive. It can be used in place of gasoline, diesel fuel and propane. Those fuels produce more undesirable gases than CNG, which is considered to be a safer form of natural gas.
Once the gas has been compressed, it is then stored in hard containers for later distribution. These storage tanks, which are designed to last more than 20 years, are typically made up of thick-walled steel, aluminum or composite materials.
Natural gas is considered a valuable resource for fueling vehicles because of the low cost and the fact that it burns cleaner than gasoline or diesel fuel. Natural gas vehicles have experienced an average reduction of 80 percent in ozone-forming emissions in comparison to gasoline vehicles.
CNG is a common source of fuel for commercial vehicles. Taxi cabs, medium-duty trucks, postal vehicles, transit buses and school buses are among the commercial applications for utilizing CNG. Natural gas powers more than 12 million vehicles on the road today.
There has even been limited usage of a home refueling appliance for people with CNG vehicles. In California, the FuelMaker Corporation unveiled such an appliance several years ago, allowing owners of CNG vehicles to refuel their vehicles overnight from their household natural gas line.
With rising gas prices, interest in CNG as an alternative fuel source has surged over the past several years. There are around 12,000 CNG fueling stations in the world right now, and about 500 of them are located in the United States.