It’s an age-old aspiration—converting garbage into something useful. That’s exactly what Battelle and other organizations are attempting to do with funding by the Defense Advanced Research Projects Agency (DARPA) for its new ReSource program.
Common military practice is to carry out or burn in place things such as empty water bottles, food packaging and human waste. DARPA’s ReSource program calls for a portable, self-contained system that can quickly convert energy-dense waste into a useful substance to support expeditionary operations and stabilization missions. This solution can solve waste logistical challenges while providing a stopgap for resupply of critical materials, which could mean the difference between life and death in the field.
DARPA has selected Battelle to develop a prototype system that uses minimal power—approximately the same as a household dishwasher—and runs autonomously with minimal intervention. For the input material, Battelle selected two of the most common plastics—polyethylene and polyethylene terephthalate. Polyethylene is commonly used in milk jugs and food packaging, and polyethylene terephthalate comprises things such as single use water bottles and food trays. The team had the choice of a variety of food, pharmaceutical and chemical outputs and selected gun lubricant because the material is both critical to warfighters in the field.
Battelle’s proposed solution will house and monitor genetically engineered microorganisms in banks of bioreactors to degrade plastic and upgrade it into a useful material. Because bacteria self-replicate, don’t use a lot of power and are shelf-stable for a long time in their dormant phase, they are ideally suited for this type of process. The challenge is to make the bacteria work fast enough.
“These processes are very slow in nature. We are working to accelerate these reactions from months to hours,” said Battelle Principal Research Scientist Jake Lilly. “Synthetic biology is all about harnessing and tailoring biology to do atypical processes that are beneficial to mankind.”
The project will also rely on the team’s materials science expertise, particularly in polymers, to determine the chemistry needed to prepare waste plastics for microbes to convert one substance into another. Systems engineering capabilities will also be essential to creating a complete and ruggedized system with an intuitive user interface that can be used with little training by any warfighter in the field.
If successful, the technology has potential to be used for a variety of other applications and the potential to redefine the lifecycle of consumer plastics.