A. Vardelle, A. Moign, University of Limoges, Limoges, France; J. G. Legoux, National Research Council Canada (CNRC-NRC), Boucherville, QC, Canada; N. J. Themelis, Columbia University, New York, NY
The environmental strategies of European Union on resources and wastes are based on lifecycle thinking. In surface finishing, they encourage the substitution of conventional wet deposition processes that involve chemicals and effluents by “dry” processes, such as thermal spraying. However, all metal finishing processes have certain impacts on human health, ecosystems, and resources. The life cycle assessment (LCA) methodology is internationally used for identifying, comparing and reducing the environmental impacts of processes and products. It requires quantifying the resources used (materials and energy) and emissions (solid, liquid and gaseous wastes) at all stages of the process (raw materials extraction, manufacturing, use and end-of-life). This study is an LCA comparison of various thermal spray processes (plasma spraying, twin-wire arc spraying, and cold spray) and electroplating for the formation of nickel coatings. It was done using a peer-reviewed database of upstream materials and energy (EcoInvent), and the LCA program SimaPro (Eco-Indicators-99). The uses of materials and energy, and the corresponding emissions of each coating process, were converted to impact scores to human health, ecosystems, and resource depletion (fossil and mineral resources).
Summary: The environmental strategies of European Union on resources and waste are based on lifecycle thinking. In surface finishing, they encourage the substitution of conventional wet deposition processes that involve wastewater and chemicals by dry processes as thermal spray processes. However, all the metal finishing processes have certain impacts on human health, ecosystems, and resources.
A life cycle assessment (LCA) is an internationally recognized methodology that provides a framework and methods for identifying, comparing and improving environmental impacts associated with a process. It typically requires quantifying resources used (materials and energy) and emissions (solid, liquid and gaseous wastes) at all stages of the process. Impacts account for raw materials extraction, energy, manufacturing, use and end-of-life. In addition, as prices for metals and energy are rising everywhere, this methodoly may help to identify the most energy- and material intensive stages of a process and thus, help to reduce the operating costs.
In this work, we use the LCA framework to compare various thermal spray processes (plasma spraying, twin-wire arc spraying and cold spray) and electroplating for the elaboration of nickel coatings which can be produced by the various technologies included in this study.
We utilize a commonly use LCA program, SimaPro and a peer-reviewed database of upstream materials and energy, EcoInvent to conduct an upstream analysis. The results are converted to impact scores along the different environmental dimensions proposed by the methodology called Eco-Indicator 99. They involve impacts to human health, ecosystems and resource depletion (fossil and mineral resources).
