Decarbonising waste-to-energy: A life cycle assessment study

With Waste-to-Energy (WtE) plants expected to play an expanding role in managing municipal solid waste (MSW), it is critical that the sector decarbonises if climate targets are to be met. Here we investigate the climate and environmental performance of capturing and sequestering (CCS) carbon emissions from WtE via process modelling and Life Cycle Assessment (LCA), exploring multiple scenarios, including e.g. carbon capture rates and MSW composition, to identify trades-offs and preferable scenarios. The LCA results show that, despite associated energy penalties, carbon capture significantly lowers climate change impacts, with WtE qualifying as a Carbon Dioxide Removal technology for capture rates above 50 %. We also find that CCS increases impacts in all other environmental categories and that the waste composition plays a key role in determining the environmental performance. Overall, we argue that economics is the chief deployment challenge, particularly because of additional transportation costs due to dispersed nature of waste.