甲烷[Methane]，最簡單的烴（碳氫化合物），化學式CH4。在標準狀態下是一無色氣體。一些有機物在缺氧情況下分解時所產生的沼氣其實就是甲烷。
液化石油氣的主要成分為丙烷[Propane],C3H8
http://en.wikipedia.org/wiki/Liquefied_petroleum_gas
LPG has a higher calorific value (94 MJ/m³ equivalent to 26.1kWh/m³
than natural gas (methane) (38 MJ/m³ equivalent to 10.6kWh/m³
, which means that LPG can not simply be substituted for natural gas.