Date of Award
Doctor of Philosophy in Industrial Engineering - (Ph.D.)
Mechanical and Industrial Engineering
Reggie J. Caudill
Athanassios K. Bladikas
Paul G. Ranky
Sanchoy K. Das
Previous research has shown that thermodynamic properties including melting point and specific heat capacity of nanomaterials may be higher than that of their corresponding bulk materials. The melting point elevation and specific heat capacity enhancement of nanomaterials may result in increased energy consumption and waste gases emission at the end-of-life (EOL) stage where the products containing nanomaterials are recycled by high temperature metal recovery (HTMR) process.
In this dissertation, the effect of physical characteristics of nanomaterials, referred to as physicochemical parameters, on their melting temperature and specific heat capacity was investigated. In addition, physical, chemical, and thermodynamic properties of nanomaterials embedded inside commercially available lithium-ion (Li-ion) battery were examined by various characterization techniques including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Thermodynamic analysis techniques with life cycle assessment (LCA) were used to investigate the environmental impacts of nanomaterials during the EOL material recovery stage due to their unusual thermodynamic properties.
As opposed to the energy analysis result, the exergy analysis showed that the chemical reactions that occur during the reduction and smelting processes are the primary sources of exergy loss. If the smelting temperature is increased to fully melt down nanomaterials with unusually high melting point, under assumptions of constant heat flux, the smelter may operate for a longer period of time resulting in substantial amount of exergy loss and carbon dioxide emission. It was also shown that the reduction process consumes larger amount of energy to raise the temperature of nanomaterials with specific heat capacity enhancement, as opposed to bulk materials. Design for environment (DFE) guideline was developed to improve process performance and risk management. Potential vulnerabilities to recycling of nanomaterials as well as recommended product design and process modifications are summarized.
Finally, a novel exergy footprint was formulated as a sustainable and environmental impact metric that provides a meaningful understanding of the environmental impact of a product or a process. The consumption and flow of exergy in the US economy is defined in terms of five functional categories: materials, transportation, food, water, and direct energy carriers. To illustrate the exergy footprint calculation, the environmental impact associated with the HTMR process measured in terms of exergy loss and exergy consumption were compared to the exergy consumption at a national level.
Olapiriyakul, Sun, "End-of-life analysis of nanotechnology products" (2009). Dissertations. 189.