Methane ndi mtundu wina wa gasi wachilengedwe, omwe amapangidwa makamaka ndi alkanes, kuphatikizapo methane, ethane, propane, ndi butane, ndi methane kukhala chigawo chachikulu.
Motsutsana, gasi wa malasha ndi gasi wopangidwa ndi zinthu zosakanikirana zoyaka, ndi carbon monoxide kukhala chigawo chake chachikulu.