|
What is Natural Gas?
Natural gas is a naturally occurring gaseous petroleum accumulating beneath the earth's crust. It is composed of hydrocarbons made up mainly of methane which is typically about 85-99% of the total volume. Its other constituents include inert gases such as N2 and CO2 and nonhydrocarbon gases, vapours and water.
What is Compressed Natural Gas?
Compressed Natural Gas (CNG) is used as fuel for vehicles. Because natural gas is in its gaseous state at ambient conditions, it must be compressed to about 16-20 MPa to achieve practical energy density for storage on-board a vehicle.
What is Natural Gas Vehicle?
NGVs are vehicles that use natural gas as fuel. There are three types of NGVs currently available. The first type requires a retrofit conversion for liquid fueled engines to run on either bi-fuel or dual fuel. A bi-fuel conversion allows the engine to run on petrol or gas but not both simultaneously, while a dual fuel conversion allows the engine to operate on either a mixture of gas and diesel or diesel only. The second type is the conversion of liquid fueled engines to a dedicated natural gas set-up. The third type is the CNG Original Engine Manufactured (OEM) vehicle.
What are the advantages of natural gas as a vehicle fuel?
Natural gas has inherent clean burning properties that enable NGVs to produce lower pollutant emissions than petrol-powered vehicles. It is a lead-free fuel that produces virtually no sulfur oxides or particulates and up to 30% less CO2. Because it is clean burning, natural gas reduces the required maintenance on vehicles.
NGVs are safer than petrol-powered vehicles. Natural gas is lighter than air and therefore, dissipates quickly. Ignition is possible only when gas to air ratio is between 5-15% by volume. Its ignition temperature is much higher than the conventional fuel (CNG-800oC, Diesel-280oC and Gasoline-500oC). CNG fuel storage cylinders are made of thick-walled aluminum or steel and are subjected to severe tests to withstand both crashes and heat which are far better than the standard petrol tank of thin sheet metal or plastic.
|
