Environmental impact analysis of food waste anaerobic digestion and products utilization process

Anaerobic digestion technology is a widely used technology for food waste treatment. It can produce clean fuel gas and realize harmless treatment of waste. Different ways of utilizing the digestion products vary depending on the market demand and production technology. In this paper, life cycle assessment (LCA) was conducted to analyse the environmental impacts of different processes in food waste anaerobic digestion treatment and compare different utilization strategies of digestion products especially the digestate. The results of this study indicated that the incineration of digestate had advantages in most environmental impacts except global warming potential (GWP), compared with composting as fertilizers. Besides that, incineration had the lower energy efficiency due to drying heat demand. The high energy conversion efficiency of internal combustion engine contributed much to reducing environmental impacts. It's worth mentioning that the sufficient combustion performance of micro-turbine resulted in smaller global warming potential (GWP) and eutrophication potential (EP).