Fuel prejudice about orgy, oddly (6)

'fuel' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'prejudice about orgy oddly' is the wordplay.
'prejudice' becomes 'bias' (biasing is a kind of prejudicing).
'about' means one lot of letters goes inside another.
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
The alternate letters of 'orgy' are 'og'.
'bias' placed around 'og' is 'BIOGAS'.

Can you help me to learn more?