Techno-Environmental Analysis of Generating Animal Feed from Wasted Food Products

摘要

The scope of this thesis was to investigate the technological and environmental parameters related to producing animal feed from wasted food products (FFP). An analysis was conducted to understand both the global and local (New York) factors affecting food waste diversion to feed. In the case of New York, the State has great potential resources for FFP, however, it is currently lacking in both visibility and a motivating factor to incentivize industry growth.;Published literature was analyzed to understand deployment of FFP operations in other global regions, including Japan, Korea, and Europe. Food waste resources available in New York State were then characterized and quantified, and a life cycle assessment (LCA) was performed on an existing FFP operation to evaluate the net impact on greenhouse (GHG) gas emissions. It was determined that the net GHG benefit was -422 kg CO2 eq. per ton of food waste processed, with by far the largest contribution (82%) being associated with the credit applied for avoidance of conventional animal feed. The greater GHG benefit realized with the subject New York State FFP operation relevant to prior studies was largely attributed to the much lower feedstock moisture content in the New York State case. The "break-even" moisture content, i.e. the point at which emissions from FFP operation exactly match the credit from conventional feed avoidance, is strongly dependent on the type of heating fuel used for feedstock drying. For the subject New York State FFP facility using wood chips and scrap food packaging for heating, the break-even moisture content was about 80%. Heating instead with natural gas dropped this critical moisture content to approximately 60%. With relatively dry feedstock, the range of GHG emissions for FFP operations is favorable compared to other food waste utilization pathways, including direct feeding to animals, composting, and anaerobic digestion.