Natural gas component (6)
I believe the answer is:
ethane
'natural gas component' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ethane that I've seen before include "Ate hen (anag) - hydrocarbon gas" , "Fuel" , "Chemical" , "Flammable gas; eat hen (anagram)" , "Athene (anag.); a colourless gas" .)