I dunno. I agree you’d need some kind of motivation for such a system, but if you settle for straight-on survival you end up with a system that turns on its creators any time the interests of Skynet and Humanity conflict. Forex, if the nations of the world all start holding hands ...
The amount of biogas required, in fact, is strictly dependent on its quality, meaning that the higher the quantity of impurities, the less effective the conversion into hydrogen will be. Moreover, the lower LHV of the landfill gas leads to a higher quantity of biogas that undergoes oxidation...