A Comprehensive Comparative Investigation of. Compressed Natural Gas as an Alternative Fuel in a Bi-Fuel Spark Ignition Engine

Nowadays, increased attention has beenfocused on internal combustion engine fuels. regarding environmental effects ofinternal combustion engines particularly as sources of pollutionand depletion offossil fuels, compressed natural gas has been introduced as an alternative togasoline and diesel fuels in many applications. a high research octane number which allows combustion at higher compression ratios without knocking phenomenon and with good emission characteristics ofunburned hydrocarbons and carbon monoxide are major benefits of compressed natural gas as an engine fuel. in this paper, natural gas as an alternative fuel in a spark ignition engine, has been considered. engine performance and exhaust emissions have been experimentallystudiedfor both natural gas and gasoline fuels in a wide range ofengine operating conditions.