Thermodynamic analysis to assess the environmental impact of end-of-life recovery processing for nanotechnology products.

The objective of this study is to use thermodynamic analysis to evaluate the environmental impact of nanotechnology products during the end-of-life (EOL) material recovery stage. A case study of the high-temperature metal recovery (HTMR) process used to recycle lithium-ion (Li-ion) batteries is presented. Previous research has shown that the melting behavior of nanomaterials may deviate from their corresponding bulk materials. The melting temperature of superheated nanomaterials in Li-ion batteries may exceed the process smelting temperature and result in nanomaterials contaminating the recovered material streams. Therefore, the smelting process must be operated at higher temperatures to ensure the full melting of the nanomaterials, resulting in higher energy consumption and process emissions. The environmental impact from the existing HTMR process is examined as well as the impact associated with operations at the higher smelting temperatures. Thermodynamic analysis, consisting of energy and exergy analyses, provides quantitative information on the resulting environmental impacts and the corresponding overall exergy loss, which may occur when recycling nanomaterial-containing Li-ion batteries.