CNG stands for "compressed natural gas." It is a substitute for gas, propane and diesel fuel. CNG is made when natural gas is compressed to less than 1% of its volume at standard atmospheric pressure.
CNG is cheaper than gasoline, and therefore a more popular alternative to many. While CNG vehicles are not as numerous as regular gasoline powered vehicles, many people today are converting their gas cars to bi-fuel vehicles. This can be done with a kit, but should be done by a professional. An extra tank needs to be added to the car and takes up some room, usually in trunk. If a car is a bi-fuel vehicle, the type of gas powering the engine can be changed by the flip of a switch.
The CNG is housed in a large chamber tank. In this tank the gas is kept at approximately 3600 pounds of pressure per square inch. As the gas leaves the tank it travels through high pressure lines to the regulator where the pressure is reduced to the amount required by the fuel injector of the vehicle.
A solenoid valve lets the CNG to move from the regulator, to the fuel injectors and to the engine. As it enters the combustion chamber it is then ignited and gives the vehicle power, just as gasoline does.
Fueling up a CNG powered car is similar to fueling up a car that uses regular gasoline. There are CNG fuel stations available, but many people are choosing to install home filling stations so their CNG tanks can be filled in the overnight hours.
Except for the cost being slightly cheaper than regular gasoline, the benefits of operating a CNG vehicle are mainly related to the environment. The CNG can produce up to 90% less polluting agents while it is burned, and it gives off up to 40% less greenhouse gas emissions.
The negative side of CNG powered vehicles are that the cars are not easy to find or you have to go through the process of conversion, CNG filling stations are harder to find, and a tank of CNG gives fewer miles than a tank of regular gasoline. When weighed with the positive benefits of using CNG, many are switching over to at least a bi-fuel vehicle to do their part to protect our environment.
