Feasibility Assessment of Low-Volume Anaerobic Digestion Systems for Institutional Food Waste Producers

Anaerobic digestion (AD) has gained popularity as an effective way to treat organic materials, produce clean energy, and reduce greenhouse gas emissions. There is a significant number of large-scale AD facilities operating world-wide, largely treating livestock wastes, and used primarily for electricity production in industrialized countries. At the same time, there are millions of small, household-scale ADs deployed in developing countries, mostly to provide biogas resources for heating and cooking. Decentralized low-volume AD systems could provide a local, renewable energy source (for electricity, heating, or both), reduce or eliminate waste disposal costs, and limit discharges of high strength wastes. The purpose of this study was to evaluate the feasibility of deploying low-volume anaerobic digestion (LVAD) systems at institutions generating significant food waste, using Rochester Institute of Technology (RIT) as a case study. Mass flows and energy balance, net present value (NPV), and discounted payback period (DPP) were used to assess the feasibility of implementing an anaerobic digestion system utilizing the campus organic waste resources. Our study showed that a positive NPV can be achieved if subsidies and incentives were applied to offset the initial capital investment. However, the economics can be improved by driving down equipment cost and accepting food waste from other establishments to generate revenue from tipping fees.