End-Of-Life Analysis of Nanotechnology Products: A Case Study Focusing on the High Temperature Battery Recycling Process

摘要

The objective of this study is to evaluate the environmental impact of nanotechnology products during the end-of-life (EOL) material recovery stage. Various engineering analysis techniques are used including computer simulation, life cycle assessment (LCA) and thermodynamic exergy analysis. A case study based on Li-ion batteries and a conventional high-temperature material recovery (HTMR) process is presented. Preliminary findings indicate that nanomaterials may have significant impacts on the environmental behavior of the recovery process. First, shredders equipped with traditional filtration systems may release nanoparticles into the atmosphere; process outputs may be contaminated by unexpected nanostructures; and, process wastes may contain hazardous or toxic nanomaterials. Simulation methods are used to investigate the penetration of nanoparticles through commercial filter media. Secondly, due to the unusual melting behavior of nanomaterials, the melting temperature of superheated nanoparticles in the Li-ion batteries may exceed the process smelting temperature and result in the contamination of nanomaterials in the recovered materials. Therefore, the smelting process must be operated at higher temperatures to assure the full melting of the nanomaterials, resulting in higher energy consumption and process emissions. The increased emissions are quantified using the Gabi 4.2 LCA software package. In addition, the first and second laws of thermodynamics provide quantitative information on these impacts and the change in overall exergy loss and efficiency that may occur when recycling nano-enabled lithium batteries.