Process optimization of adsorbent production from waste printed circuit board non-metallic fractions based on...

The non-metallic fraction (NMF) generated during waste printed circuit board (WPCB) recycling represents a major challenge for electronic-waste management because of its limited recycling opportunities and potential environmental burden. Although NMF can be converted into value-added ion-exchange adsorbents, the environmental implications of adsorbent production remain largely unexplored. To address this knowledge gap, a cradle-to-gate life-cycle assessment was conducted to quantify the climate-change impact (CC) and cumulative energy demand (CED) of ion-exchange adsorbent production from WPCB-derived NMF. Four production routes differing in water consumption and moisture-management strategy were evaluated to identify preferable process configurations and major environmental hotspots. Substantial differences were observed among the evaluated routes. On the basis of 1 kg NMF processed, CC decreased from 33.1 to 5.18 kg CO₂-eq, while CED decreased from 737 to 126 MJ across the scenarios. Relative to the baseline configuration, the concentrated-paste route reduced CC and CED by approximately 84% and 83%, respectively. Electricity consumption associated with moisture removal and thermochemical conversion was the dominant contributor to both indicators, whereas potassium hydroxide became increasingly important as electricity-related burdens declined. These findings demonstrate that process-design optimization, particularly improved moisture management, can substantially reduce the CC and CED associated with WPCB-derived NMF valorization.