A Novel Hybrid Network Optimization Model for Printed Circuit Boards Recycling: A Circular Economy Perspective

Due to the rapid advances in technology, increasing consumption rates and continuously released new products lead to shorter product life cycles, putting the sustainability issue under the spotlight. This, in turn, creates an unmanageable amount of waste that needs immediate care. Electrical and electronic equipment is one of the major contributors to this waste given that millions of metric tons of electronic waste are generated across the world each year, and only an insignificant percentage of which is recycled. The recycling of printed circuit boards, which accounts for considerable monetary value in waste electrical and electronic equipment has long been ignored due to the serious challenges in collection, dismantling, and recycling processes. In this study, the open-loop and closed-loop supply chain involving circular economy objectives is designed in order to increase the recyclability of valuable metals including gold, silver, copper, and palladium. In this regard, a mixed-integer linear programming model is developed that aims at maximizing the profit from the flow in the supply chain network. The model was tested with actual data obtained from a printed circuit board firm in Turkey that aimed optimal distribution in its supply chain. The results reveal that the product/material flows, which have an impact on the revenues, were among the most important factors affecting profitability. Considering the circular economy objectives, the revenue obtained in the hybrid open-loop and closed-loop supply chain is predominantly provided by the reuse and repair activities. In addition, the boundaries of the proposed model are tested with sensitivity analyses and the results are discussed extensively with conclusions on managerial implications.