Board Thread:Speculation House/@comment-25479664-20160418125948/@comment-25479664-20160418181219

Also even if Remnant doesn't have fossil fuels, they still have the capacity to make biofuels. Assuming that autotrophic prokaryotes still exist, Remnant can make biofuel from:

Feces (yeah its disgusting, but it produces methane, which can be concentrated and stored, though it generally doesn't burn very well

Corn (popcorn needs corn, and corn can be made into ethanol)

Various other oily vegetables, fruits, and nuts

Algae

AND not to mention that we see loads of firearms that don't use dust propellants, which means that remnant can manufacture those (though things like gunpowder can't be used as fuel for anything more complex than a missile).

Even we know that relying on just one source of fuel is too bad; during WW2, Hitler was so desperate to secure oil fields in Russia and the Middle East that he led an entire campaign to take the Suez Canal. He didn't diversify his energy production (though really noone did at the time), and well, he couldn't fuel his mechanized forces and lost WW2. NOW most armies are at least researching alternate fuels so that if their main supplies are tapped they have a backup.