Converting food waste to usable energy in the urban environment through anaerobic digestion

Abstract

Urban sustainability is a subject of recent focus in North America, and Canada specifically. As our urban areas continue to grow and consume large quantities of energy and produce massive amounts of waste, we are faced with the challenge of how to manage this situation in a way which is both responsible and sustainable. One feasible urban waste-to-energy technology is anaerobic digestion. Anaerobic digestion (AD) has been a usable energy source for over 100 years and is currently being employed in several countries around the world in rural settings to generate electricity and heat, but it has yet to make a large migration to the urban environment even though it is a viable and mature process. Applied to the organic waste produced in urban environments, anaerobic digestion could provide a critical solution to growing garbage problems while simultaneously reducing external energy requirements. As landfills across Canada and the rest of the world are filled to their limits, a carbon-neutral process which can locally generate electricity and heat while providing up to 50% volatile solid reduction is something to be seriously considered. As fuel prices continue to inflate, the cost of transporting waste outside of cities to landfills will continue to rise. Large portions of this waste could be retained, digested, reduced, and converted into useable energy in the urban environment providing valuable energy. This paper investigates the feasibility of urban anaerobic digestion and provides a case study from the downtown campus of Concordia University in Montreal, Canada.