Food Waste Diversion from Landfills: A Cost-Benefit Analysis of Existing Technological Solutions Based on Greenhouse Gas Emissions

Landfill disposals of food result in fugitive emissions of methane-a powerful greenhouse gas (GHG). This desktop study focuses on the cost and GHG emissions associated with food waste diversion from landfills using aerobic digesters with liquid outputs (ADLO). Despite the emerging popularity of ADLO units for food waste disposal, their cost and the GHG emissions associated with their use have not been independently quantified and compared to those of other food waste management options. This study compared landfill disposals, the currently available composting services, electric food dehydrators, and in-sink waste disposal units (garbage grinders). For a food waste production rate of 30 kg d(-1), the landfill base case showed the lowest cost at USD 23 week(-1). The modeled ADLO cost ranged from USD 20-42 week(-1), depending on performance. Dehydrator costs were high at USD 29 week(-1), largely due to the high energy intensity of the process. The cost of the current centralized composting was USD 51 week(-1). The ADLO option with good performance was estimated to produce 5% of the GHG emissions of a landfill. This study showed that well-performing ADLO technology can be economically competitive with landfills and centralized composting and can markedly reduce GHG emissions.