Life cycle assessment of repurposed waste electric and electronic equipment in comparison with original equipment

Abstract

Reuse is considered as a priority alternative for the management of Waste from Electrical and Electronic Equipment (WEEE). The reason is that it is thought that reuse always has a lower environmental impact. However, few studies have evaluated in detail the environmental impacts of reuse, and even fewer have analysed cases of reuse for a purpose other than the original one. In this study, life cycle assessment (LCA) following the ISO 14040 standard, was employed to assess the environmental impacts of two preparing for reuse processes of desktop computer considered as WEEE, whose results were repurposed products with industrial application: a programmable logic controller (PLC) and a perimeter security system (PSA). These scenarios were compared with other equivalents in which the products come from virgin raw materials. The results showed a worse environmental performance of repurposed PLC than one original, due mainly to differences in distribution and use stages. The greater weight, the shorter lifespan and mainly the higher operating power were responsible for the greater negative effects of the reuse scenario. However, repurposed PSA has a lower negative impact than original equipment in all environmental categories analysed. This was mainly due to its lower operating power and also not having demanding technical characteristics. Therefore, in this case, the usage profile, the composition and the lifespan can be considered as the main factors that determine the environmental advantage of repurposed products. The main conclusion of this work is that the environmental viability of the reuse of WEEE depends on the existing commercial alternatives for the application of the new product obtained; being one of the main factors the power consumption and the lifespan. This constitutes an important aspect to take into account when developing regulations, strategies and policies to prevent the implementation of WEEE management systems with environmental impacts greater than other alternatives. Further, the specific information about environmental performance of repurposing can contribute to the development of new processes of preparing for reuse. In this way, the commercialization of new products from these processes is favoured, which contributes to improving the environmental management of WEEE and the development of the circular economy.