Feasibility Study for a Campus Digester
Fall 2015 - Spring 2016
In fiscal year 2014, Duke University and the School of Medicine produced over 1,900 tons of compostable waste. The majority of this waste makes its way to landfills, where it produces methane, a potent greenhouse gas, and leachate that can pollute ground and surface water.
Anaerobic digestion technology can mitigate these problems, allowing for organic waste to be diverted and used to produce methane. Captured methane can then be used as an alternative fuel, and by-products from the digestion process can also be used as fertilizers and soil amendments. But to integrate such technology into the existing waste management system on the Duke campus poses significant operational challenges.
This project set out to identify those challenges, assess how they might be answered and pave the path for a significant contribution to the University’s goal of climate neutrality by 2024.
Team members conducted a feasibility study comprised of a food waste audit at Duke, a survey of relevant federal, state and university policies and an economic modeling exercise.
The team identified several obstacles to operation of an on-campus digester, and the economic feasibility analysis indicated that such a digester would not be cost-competitive given the low electricity rates paid by Duke and the low price of natural gas. However, the team members concluded that a small food-waste digester could be justified on the basis of its educational value if students were allowed to design and build it on campus, using it as a learning lab.
Amanda Duggan, Andrew Seelaus, Wusi Fan, Heng Ye, Yeon Ji, Jake Steinberg
Marc Deshusses, Jay Golden, Brian Murray
Duke Carbon Offsets Initiative, Facilities Management Department, Pratt School of Engineering
Air & Climate, anaerobic digestion, composting, Energy, Research, Waste, waste