U.S. Army to Generate Electricity from Kitchen Waste
San Francisco Gate reports that the US Army is preparing to deploy to Iraq two 4-ton "tactical biomass refineries" designed to turn piles of trash into electricity. "Each can run for 20 hours on a ton of trash, producing enough power to light a small village."
The novel machines were built by defense contractors and Purdue University scientists as part of the Army's push to reduce troops' diesel fuel use in Iraq, where convoys are frequently targeted by insurgents.
The design sounds quite elegant, yet it is complex; so the first step is to field test the prototype in Iraq.
Nate Mosier, an assistant professor of agricultural and biological engineering who is overseeing the work at Purdue, said the refineries are unique in their ability to burn multiple fuels at once. They're also portable, designed to fit snugly into a standard shipping container.
The trash-to-energy process begins when unfiltered garbage is fed into a chute, falling into a grinder that chews the trash into small pieces.
Organic food waste heads to a bioreactor where an industrial fermenting process produces ethanol. In another chamber, plastic, cardboard and other trash items are heated to create low-grade propane or methane.
Those gases and the ethanol are then combusted in the refinery's modified diesel engine, which powers a 60-kilowatt generator [possibly similar to the one pictured].
About 10 percent of the electricity the refineries produce are used for the machines' power needs, but the remaining 90 percent would be available for the troops.
Like all trash to energy projects, utility hangs on reliability and maintenance cost. If you only have one and it breaks or needs an overhaul, you are in a black out. So, you'd still need diesel fuel backup for those periods.
And they better be careful not to have a few bullets left on the cafeteria trays!
Via::SF Gate, "Army to Turn Trash Into Power in Iraq" Image credit::Defense Link, Photo Archive, "U.S. Air Force airmen, assigned to the 62nd Aircraft Maintenance Squadron, work together pushing an 86 diesel generator in place at McChord Air Force Base, Wash., Jan. 24, 2006..." (excerpted)