Turning food waste into fertiliser in Pittsburgh

Pittsburgh International Airport is actively working to cut back aviation-related emissions, through a new partnership with Pittsburgh-based Ecotone Renewables.

Joining the airport’s xBridge innovation program, one of the company’s digesters has been stationed outside the landside terminal and nicknamed ZEUS translating as Zero Emissions Upcycling System.

Launched in 2020, ZEUS aligns well with the programme which has a proven record of working with both established and startup technology companies to develop tech solutions for aviation and other industries at PIT.

Inside the 8ft by 20ft cargo container is a complex system of pipes and tanks that takes the concept of composting waste and supercharges it – approximately eight times faster than normal composting.

Fully automated and self-sufficient, the fertiliser tank is drained once a week via a spigot mounted on the exterior.

“Food waste is bad for business,” said Dylan Lew, CEO and co-founder of Ecotone. “I think we’ve created an amazing solution for our customers because we not only reduce waste odours and greenhouse gas emissions, but when it comes down to the bottom line, we reduce costs.”

Employees from the landside Dunkin’ concession drop in over 200kg of food waste a week via a chute on the outside of the container.

The surplus coffee grounds offer robust nutrients for fertiliser, and sugary waste such as donuts and muffins are prime sustenance for the bacteria and microbes that are critical to the digestion process. The waste is then ground up, mixed with collected rainwater and fed through the system.

Three weeks later, 50 gallons of nutrient-rich fertiliser is made and ready to sell, along with leftover biogas that is purified and used to power the system.

According to the United Nations, aviation accounts for 2% to 4% of global carbon emissions with 8 percent of greenhouse gas emissions produced by food waste in landfills worldwide.

Giving back to the community, Ecotone donates 10% of its ‘Soil Sauce’ fertiliser to local community gardens in Pittsburgh. The remainder is sold to local farmers and home gardeners in 50+ retailers.