One of the biggest problem areas that a military force faces in a time of conflict is maintaining supply lines to the troops. Keeping troops fed and fueled is critical. To that end, being able to maximize fuel efficiency, and also getting fuel wherever possible is beneficial. Scientists at Purdue University have developed a portable biorefinery that can be used to turn trash and waste into energy and could easily be widely applicable for civilian use.
The unit separates organic food waste from other trash and processes each of these separately. The food waste is processed to produce ethanol, and the residual waste from that process then go to a gasifier to produce propane and methane. The ethanol and gas are then burned in a modified diesel engine with a generator to produce electricity. These types of units would be ideal in disaster areas for processing waste and generating power. Because the CO2 from the combustion process is not from fossil fuels, the entire process is relatively carbon-neutral. The unit runs on regular diesel initially to get the ethanol and gasification process started, but once fuel is being generated, it is self sustaining as long as it is fed waste. Including the diesel fuel used to initiate the process, the unit generated ninety percent more energy than was put in.
A system like this could be used at the neighborhood level to provide power and get rid of waste, or smaller scale units could potentially be at the residential level and even provide power back to the grid. This could greatly reduce the amount of waste that has to go to landfills. since the only waste is a some ash. The ash has about a 30 to 1 volume reduction compared to the original input material.
[Source: Purdue University]