by Mr. Don Kennedy
The year was 2008, and with the ongoing war, Iraq was a dangerous landscape for Soldiers on the ground, especially convoys traveling to and from base camps. Soldiers transporting fuel frequently encountered roadside bombs and enemy ambushes. Those risks can now be reduced with the Tactical Garbage to EnergyRefinery (TGER) prototype.
“If you’re a forward operating base, you don’t want a local contractor coming in to haul your garbage out, because you don’t know if they’re good guys or bad guys. You also don’t want to be hauling fuel in, because those convoys are targets and risk the lives of Soldiers and contractors,” said Dr. James J. Valdes, the Army’s scientific advisor for biotechnology at the U.S. Army Edgewood Chemical Biological Center (ECBC), Aberdeen Proving Ground (APG), MD. ECBC is the Army’s principal research and development center for chemicaland biological defense technology, engineering and field operations.
For 90 days, Camp Victory in Baghdad was home to the first two prototypes of TGER, deployable machines tactically designed to convert military field waste into immediately usable energy for forward operating bases (FOBs). The trailer-mounted biorefinery system uses hybrid technology to support a 550-person unit that generates about 2,500 pounds of trash per day; it converts about 2,000 pounds of that garbage—paper, plastic, packaging and food waste—into electricity using a standard 60-kilowatt diesel generator.
THE PRESSING PROBLEM
At the height of the war in Iraq, eight incinerators were operating around the clock to burn waste generated by Camp Victory, according to Valdes. Nearly 12,000 gallons of fuel per day were needed to power the incinerators.
“It was very expensive. During the expeditionary phase of warfare, it can cost as much as $400 per gallon for fuel … because the fuel has to be flown in by plane or helicopter. It’s also a security risk,” Valdes said.
The senior technologist identified a need to generate power tactically for small units in theater, using a method that would not just dispose of trash but could also produce energy to sustain base camps, eliminate the cost burden and reduce security hazards. Camp Victory provided the opportunity to test the TGERs in theater.
“We picked a forward operating base in Iraq because we wanted to really stress the system. All other waste-to-energy systems had been tested in laboratories or under ideal conditions and temperature climates. What we really wanted to do was stress it with heat, sand and real-world trash in a low-infrastructure environment,” Valdes explained.
“You know that old Chinese saying, ‘Be careful what you wish for, you might get it’? Well, we got it. We learned an awful lot over there about what works, what doesn’t work and what’ll break.”
TGER’s hybrid technology uses thermochemical and biocatalytic components to produce two different kinds of fuel. The thermochemical component turns trash into synthetic gas through a gasification process, while the biocatalytic component produces ethanol from liquid waste. The two different fuels are then blended together to power the generators.
Of the lessons learned while the TGER was deployed in Iraq, the most valuable was that the downdraft gasifier had a tendency to get clogged if there was too
much plastic in the fuel pellets. In addition, a large percentage of the synthetic gas was inert and could not be used as viable fuel. As ECBC’s project director for TGER, Valdes led a team that successfully re-engineered a new prototype, TGER 2.0, to address concerns that surfaced during testing.
A horizontal gasifier with an auger device was developed to rotate the trash, eliminating the mechanical step of pelletizing it. The TGER 2.0 prototype also injects steam into the gasifier, which allows a larger conversion of output gasto become energetic. According to Valdes, the old system produced 135 BTUs (British thermal units) per cubic foot of gas, whereas the TGER 2.0 prototype produces 550 BTUs, more than tripling the amount of usable energy.
TGER 2.0 also features an automated interface with a touch-screen panel, making it easier for workers to input information and monitor every part of the machine, from oxygen levels in the gasifier to ethanol production and power output. It used to take three techniciansto operate the machine. Now it takes two people: one to feed the garbage and another to monitor progress. Valdes hopes that as the prototypes advance, TGER eventually could require only one technician or Soldier to operate.
The advanced prototype was shipped back to the manufacturer for modifications after a final 80-day field trial at APG, where the green technology was tested to see how long it could run at maximum garbage input. The result: Within two hours of powering on, TGER 2.0 can
make synthetic gas that enables a generator to run at about 75 percent power. Within 12 hours, alcohol is produced and blended with the synthetic gas to run the generator at full power at a steady state.
As part of the U.S. Army Research, Development and Engineering Command, ECBC has been pursuing opportunities to address critical issues for the warfighter with greater efficiency and productivity. Biotechnology is one area that Valdes is tapping into.
“Over the billion years or so that we’ve had life in various forms on this planet, nature has evolved ways to manufacture very complex things, from chemicals to people,” Valdes said. “Bio-manufacturing is the ability to harness nature to manufacture things that you cannot produce through synthetic chemistry. It’s harnessing the power of nature and the information in the genes to make products that are very difficult or impossible to manufacture chemically.”
The environmentally friendly TGER 2.0 has a zero carbon footprint, reducingthe volume of waste in a 30:1 ratio. For example, 30 cubic yards of trash becomes one cubic yard of ash, a benign soil additive tested by the U.S. Environmental Protection Agency that is safe enough to use for rose bushes.
The new TGER prototype is useful not just in military applications; it also could be transitioned to the commercial sector, said Valdes.
“Longer term, we will be talking to the PMs [project managers] about transitioning it, but we’ll also be talking to some companies that support oil and gas operations in places such as Mongolia and parts of the world that are difficult to have camps in,” he explained.
Oil and mining operations, campsites, hospitals, mess halls and even areas recovering from natural disasters such as Hurricane Sandy are just a few of the places where the green technology could prove beneficial. ECBC and SAIC recently entered into a cooperative research and development agreement to speed commercialization of the technology.
“TGER is geared toward a smaller base camp, but industrial operations start off small and build up. They still have to get rid of garbage, and they have to somehow get energy into remote outposts. If you think about it, there are far more commercial opportunities for TGER than there are Army applications,” Valdes said.
ECBC and SAIC are also working with TGER Technologies Inc., Defense Life Sciences LLC and Purdue University.
For more information about ECBC, visithttp://www.ecbc.army.mil/ or call 410-436-7118.
MR. DON KENNEDY is the communications and public affairs officer for ECBC at APG. An eight-year veteran of the U.S. Navy, he has also served as chief of media production at the U.S. Army John F. Kennedy Special Warfare Center and School, and managing editor for the Mid-Atlantic region of the Navy’s largest newspaper, The Flagship. He holds a B.A. in English and history from Christopher Newport University.