Environmental performance analysis of innovative mechanical separation for recycling of waste printed circuit boards

The accumulation of electronic waste (e-waste) poses growing environmental challenges, amplified by the release of toxic brominated compounds in traditional recycling approaches. Printed circuit boards (PCBs), a key component of e-waste, provide an opportunity for resource recovery through advanced mechanical separations. This study evaluates the environmental performance of a developed mechanical separation process for PCBs using the Environmental Footprint 3.1, IPCC Global Warming Potential, and Cumulative Energy Demand methods. The analyzed process attempts to recover enriched outputs, including a copper concentrate and an epoxy and ceramics concentrate, aiming at delivering an efficient metals recovery, producing phenolic derivatives, and reducing bromine emissions in downstream materials recovery. Results reveal that 7–12% of the initial waste PCBs is liberated as an epoxy-rich concentrate, which, alongside the copper fraction, demonstrates potential for impact mitigation across the recycling chain. However, the process requires a cumulative energy demand of 1658.7 MJ and emits 99.9 kg CO2-eq per ton of PCBs. Size reduction was identified as the most energy-intensive step, due to the high energy demand of millimeter-scale material reduction needed for the inertial and electrostatic separations. Sensitivity analysis highlighted the influence of regional energy profiles, with a lower dependence on fossil-based electricity significantly reducing impacts. The study also noted the disproportionate impact of recovered materials, with the copper concentrate showing a high price-weighted CO2-eq of 0.28 kg and 4.6 MJ energy demand per kg of liberated copper concentrate. The environmental impact per unit of economic gain for the copper concentrate evolves over the process to an order of magnitude higher than that of the initial input, with transportation dominating the impact. These findings emphasize the potential of advanced mechanical separation to address e-waste concerns, while identifying areas for improvement toward a more sustainable recycling framework.