Waste to energy, landfill methane, waste to jet fuel

[NNadir]

4. Fischer Tropsch is of course a topic worthy IMO of discussion by scientists.

The topic is, however, very broad.

The point you raise is a thermodynamic question. In general, under most conditions, practically all conditions, waste to energy wastes energy, but under certain circumstances this is justifiable.

Waste to energy programs using what might be "waste" heat, can actually recover some exergy from that heat, at least under conditions where high temperatures are involved.

As for E&E, thermodynamics is not a popular topic over at E&E; much of what is written there either deliberately ignores the topic or pretends it doesn't exist. In my view, after much experience with that forum, science is definitely not a "thing" there.