Natural Gas Engines
Compressed natural gas (CNG) is a cleaner fuel than gasoline (petrol, petroleum, benzene, call it what you like) and diesel and is used extensively in countries such as Argentina, Brazil, Canada, Iran, Italy, Pakistan, India, China and the USA, and is rapidly becoming popular in many other countries, including Thailand.
The energy efficiency of CNG is generally equal to that of gasoline, but lower compared to modern diesel engines. Gasoline engines converted to run on CNG suffer because of their low compression ratio, resulting in a reduction in delivered power of about 10 percent to 16 percent.
However, engines manufactured specifically to run on CNG use a higher compression ratio due to this fuel’s higher octane number of 120-130.
CNG is composed of methane, and is refined from natural gas found most frequently in oil-fields.