With a zero carbon footprint, the improved TGER 2.0 prototype reduces the volume of waste in 30 to one ratio. According to ECBC scientist James Valdes, 30 cubic yards of trash could be reduced to one cubic yard of ash. (Army)
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The Army is the biggest service by number of personnel, but it uses less fuel than the Air Force or the Navy. A look at the numbers:
21 million barrels: Army’s use of petroleum fuel in fiscal 2011.
$560 million: Army’s 2013 budget request for operational energy initiatives
$4.1 billion: The request through 2017; $3.3 billion is for new equipment, and $832 million is for research.
The Army is working on turning trash into energy to reduce dependence on fuel convoys and local garbage-hauling contractors in the war zone.
The prototype Tactical Garbage to Energy Refinery 2.0 has completed field trials to power a 550-person camp that generates 2,500 pounds of trash per day.
The project, still in the early stages, represents a dramatically different way to use resources.
Take Camp Victory in Iraq, which in 2008 was using 12,000 gallons of JP-8 fuel per day to run eight incinerators that burned the camp's trash. Cost estimates for burning that much JP-8, commonly used as jet fuel, was about $25,000 per day.
Rather than burning fuel to burn garbage, TGER 2.0 uses a hybrid system that combines two complementary technologies, advanced fermentation and thermal decomposition, to convert 2,000 pounds of garbage — paper, plastic, packaging and food waste — into electricity for a standard 60-kilowatt diesel generator.
The refinery can reduce 30 cubic yards of trash to one yard of benign ash.
"You can throw it on your garden," said James Valdes, scientific adviser for biotechnology at Edgewood Chemical Biological Center, which helmed the testing of the refinery.
There are other advantages, such as the safety of soldiers.
"Troops in theater have to truck in fuel and truck out garbage, and that's dangerous on both counts," Valdes said. "You also have to have contractors to take care of the trash, and they might be a risk. And where they take the trash might be a [public relations] problem and a public health problem."
There has been no public decision yet to mass-produce the refinery. But as the Army draws down from large-scale combat operations, the service has an opportunity to examine "novel technologies for the future force," such as this one, Valdes said.
"It's got real civilian applications, and if you picture a post-Katrina or post-Sandy event, where there's not enough fuel and plenty of trash, you could really put them to use," Valdes said.
How it works
The system works by converting trash into both a synthetic gas and ethanol, and it blends the two, injecting the mixture into a generator. It replaces the diesel fuel normally used to run the generator, which produces the electricity.
Because fermentation, the biological process used to make ethanol, does not handle plastic, the creators adapted a chemical process known as gasification, which uses high temperatures and pressure, with little oxygen, to transform the carbon-containing materials into a synthetic gas. The process doesn't burn the trash but transforms it chemically.
"These weren't new technologies, but when we looked at the waste streams a base camp generates, we realized that one or the other technology wouldn't be sufficient for the trash stream or the power we wanted to put out," Valdes said.
In 2005, Valdes developed the idea for the first garbage-to-energy refinery under a small-business innovation program, and he fielded the first prototype to Camp Victory in 2008 under the Rapid Equipping Force.
"We couldn't find a program of record that was funding tactical alternative sources of power, so we essentially created one out of the [small business innovation] program," Valdes said.
The original prototype was developed with SAIC, Defense Life Sciences and Purdue University.
Iraq was the best place for the three-month test because it supplied enough heat, dust and trash to learn what pieces of TGER 1.0 would work and what would break in an austere environment.
"We wanted to really stress the system," Valdes said. "Everything works perfectly in the laboratory, but this is the first of this type of system that has been fielded in that type of environment."
Though incinerators are simpler and a better-known technology, they need to consume fuel to run and do not typically generate power. Their heat can be captured to create steam heat, but it's not a very efficient process, Valdes said.
In 2011, Valdes' team built the new TGER prototype, which includes a more efficient gasification system, easier-to-use controls and a steam system that keeps melted plastic trash from gumming up the works.
The previous version's gasification system provided 135 BTUs per cubic foot of synthetic gas, and the newest version generates 550 BTUs per cubic foot.
The total output could power as many as two 60-kilowatt generators, possibly one-third.
The hope is to interest a formal Army acquisitions office and eventually field the devices.
The Army is readying reports on the tests, which ended in September, Valdes said.