Sourcing Energy from Waste in the Circular City: Integrated Anaerobic Digestion Toward Long-Term Decarbonization of Cities

Long term decarbonization strategies within the built environment can look to alternative energy mechanisms which redirect waste resources as inputs to other systems. Circular City models of sustainability accordingly look for potentials to close loops, turning waste into resources and reducing pollution. Organic material such as food waste contains significant energy which can be processed by the unique metabolisms of microbes into useful gasses and heat. Anaerobic digesters are one such technology which harness microbial capabilities of fermentation to sustainably process resources and harvest energy in a controlled environment from what would otherwise be merely wasted. We seek here to explore this underutilized potential and ask what it means for buildings, communities, and their designers, who seek to advance increasing sustainability and reduce waste and pollution in the built environment. Case studies and associated carbon footprint impacts will be calculated and analyzed. Finally, opportunities to leverage this long term decarbonization approach will be discussed, and potential environmental impacts to the carbon cycle contemplated.

Keywords: Circular City, Anaerobic Digestion, Waste-to-Energy, Systems Integration, Sustainability