Waste-to-Fuel Open House draws crowds to sustainable energy production

Experimental anaerobic digester explores university's options for waste conversion

M.C. Tilton
October 23, 2015


On a hill above The Ridges, beside the Ohio University Compost Facility, a huge grey pillowy bladder sits inside an almost unbearably hot glasshouse. The bladder churns food waste and compost and turns it into fuel. It’s an interactive process that makes for a perfect open house – and that’s just what Assistant Professor Sarah Davis and Research Scientist Kim Miller did at their Waste to Fuel: Bioenergy open house on Oct. 7.

The bladder is an integral part of a larger system of anaerobic digesters. Developed and built from scratch by Voinovich School of Leadership and Public Affairs researchers Davis and Miller, the digestion system is co-located at the Ohio University Compost Facility, which is the largest in-vessel composting system at any college or university in the nation. More than 70 visitors attended the open house, providing them a unique opportunity to explore the next generation of energy production for transforming waste not only into fertilizer, but also a sustainable energy source.

Campus food waste is already composted at a facility on The Ridges, but the facility receives more and more waste each year. Davis and Miller’s digester takes some of that excess waste and processes it into a useable fuel source: methane. Four dry digesters and a wet one absorb compost and produce biogas and fertilizer. The fertilizer is tested on hydroponic plants in the glasshouse, and the biogas is placed in bags that are transferred to propane tanks.

The system that Davis and Miller built is suitable for families who produce their own fuel, as is common in Costa Rica, where the bladder was manufactured. The methane compressed from the small system is ready to run in a generator or be burned for heat – or both.

“We really wanted to integrate a sustainable energy system to make it more holistic,” Miller said. “The opportunity we have to make useable fuel here is truly unique.”

In fall 2014, Davis received an Ohio University Foundation 1804 Fund grant to build the anaerobic digester. Because it is sensitive to outdoor temperatures, the actual digestion process began in May 2015 and will continue through warm months.

In addition to the inside look at the anaerobic digester, visitors enjoyed tours of the Ohio University Compost Facility and bioenergy crops planted in the Land Lab at The Ridges.

The Advanced Bioenergy Systems: Waste to Fuel project is a joint effort among Davis, Miller, Director of Facilities Management Steve Mack, student designers, research assistants and many other collaborators. Although the digester operates as an experiment now, the researchers hope to determine if the methane biogas production is a viable and sustainable option that the university can pursue on a large scale.