Alternative types of internal combustion
Compressed or liquefied natural gas
Natural gas is a mixture of hydrocarbons, mainly methane (CH4 ). The highlights that make natural gas an interesting alternative fuel are, mainly, it is clean burning, and produce significantly fewer harmful emissions than re-formulated gasoline or diesel when used in natural gas vehicles and its commercial availability to end users. Because of its gaseous nature, when used as a vehicle engine fuel, natural gas must be stored onboard either in a compressed gaseous state (CNG) or a liquefied state (LNG). As an interesting fact, it can be mentioned that Sweden is the leading natural gas user in the world. Natural gas is domestically produced and readily available to end-users through the utility infrastructure. In addition, commercially available medium and heavy-duty natural gas engines have demonstrated over 90% reductions of carbon monoxide (CO) and particulate matter and....