Life Cycle Assessment of Plastic Waste End-of-life Treatments in Singapore
Ken Shaun Yap, Yong Jie Leow, Si Ying Chung, Clarice Loke, Daren Zong Loong Tan, Zhiquan Yeo, Jonathan Sze Choong Low
Abstract
In Singapore, about 900,000 tonnes of plastic waste is being disposed of annually, making it one of the major waste streams. However, at 4% recycling rate (in 2019 and 2020), plastic waste has one of the lowest recycling rate compared to other waste streams such as metal and paper. Most of the plastic waste would be incinerated at waste-to-energy (WTE) plants. In a bid to address the environmental impacts of the various plastic waste end-of-life (EOL) pathways in Singapore, life cycle assessment (LCA) was performed, whereby the treatment of 1 kg of plastic waste was selected as the functional unit. The EOL pathways include domestic mechanical recycling, baling for overseas recycling, and WTE incineration. Three environmental impacts were considered, i.e. global warming potential, cumulative energy demand and water depletion. These indicators were used for hotspot analysis to identify areas within the system boundary that could be prioritised for mitigation actions, as well as sensitivity analysis to ascertain the robustness of the LCA results and their sensitivity to some uncertainty factors in the study.