Life cycle assessment of the present and proposed food waste management technologies from environmental and economical inpact perspectives

• Main Authors: Ahamed, Ashiq, Yin, Ke, Ng, Bernard Jia Han, Ren, Fei, Chang, Victor Wei-Chung, Wang, Jing-Yuan
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2016
• Subjects: LCA; Food waste; Hydrothermal carbonization; Anaerobic digestion; Incineration
• Online Access: https://hdl.handle.net/10356/80709; http://hdl.handle.net/10220/40741
• Institution: Nanyang Technological University

Proper food waste management has been a growing concern for densely populated urban cities, like Singapore. The current practice of incineration is questionable in terms of environmental and economic sustainability. In order to alleviate the environmental impacts and improve resource recovery, alternative solutions for food waste management i.e. food waste-to-energy biodiesel and anaerobic digestion has been proposed through life cycle assessment. The functional unit of the study was set to be 1 tonne of food waste. The systems boundary included the collection, processing, waste conversion and disposal of food waste. Process data were obtained from lab-scale experiments, literature, and from SimaPro 7.3 libraries. The impact categories were assessed in terms of acidification potential, eutrophication potential, global warming potential for 100 years, and cumulative energy demand using the CML 2 baseline 2000 version 2.05 method and the CED version 1.08 method. A cost-benefit analysis was also performed for the studied scenarios. The life cycle assessment results have shown that food waste-to-energy biodiesel system is favored for food waste with oil content >5% and anaerobic digestion for oil content ≤5%. The cost-benefit analysis results have shown that anaerobic digestion is the best choice if applicable in the local environment. Otherwise, food waste-to-energy biodiesel is the preferred choice over incineration. In conclusion, this study presents the advantages of anaerobic digestion and food waste-to-energy biodiesel system in comparison with incineration of food waste. The results of this study suggest a need for adaptive strategy based on food waste type and composition, and provide decision makers in Singapore with insights into the three food waste management strategies and directions to improve the existing system.