Towards sustainable recycling processes: Wasted printed circuit boards as a source of economic opportunities

In modern society, use of natural resources poses a great challenge. However, the circular economy paradigm has defined a new concept of waste, proposing it as a business opportunity. Of particular interest in this paradigm is 'waste electrical and electronic equipment' (WEEE), given its high growth rate, and 'wasted printed circuit boards' (WPCBs), which are the most valuable component of WEEE. Although WPCB recycling is currently dominated by large firms, the present work evaluates the economic feasibility of hydrometallurgical processes, as used within small and medium enterprises (SMEs). Discounted cash flow (DCF) is used as a reference methodology and net present value (NPV) is used as an economic performance index. The analysis is conducted on three categories of WPCBs (low-, medium- and high-grade) and 15 categories of e-waste. The results underline the key role played by the market price of Au and Pd, plus the purchase cost of WPCBs. Accordingly, sensitivity, scenario and risk analyses are conducted on these variables and a break-even point (BEP) analysis is used to define the exact values for which economic feasibility is verified. NPV is shown to vary from 6.8 million E for medium-grade WPCBs to 63.0 million E for high-grade WPCBs in a baseline scenario, with a negative (unprofitable) result (NPV of -2.8 million E) for low-grade WPCBs.