Closing the loop of membranes by recycling end-of-life membranes: Comparative life cycle assessment and economic analysis

Abstract

Membrane technology has been widely adopted in various industries. However, the inappropriate disposal of end-of-life (EoL) membrane is an urgent issue impeding the sustainability of membrane technology. Herein, we proposed a closed-loop pattern for membrane use by employing upcycling EoL low-pressure membranes and downcycling EoL high-pressure membranes. Life cycle assessment and economic analysis showed that applying the closed-loop recycling strategy could reduce the environmental impacts by 22–27%, in which 24% CO2-eq emissions would be saved with about 27.1% economic advantages, thanks to the reduction of new membrane production and EoL membrane disposal. Sensitivity analysis indicated that more benefits would be achieved through membrane recycling if the project lifetime or the recycled membrane lifetime were extended. Monte Carlo analysis suggested that the closed-loop scenario had less potential to create more environmental impacts than the non-recycling scenario. These results implied that the closed-loop recycling pattern provided a promising paradigm for sustainable membrane application.