Pyrolysis and catalytic reforming of ABS/PC and PCB using biochar and e-waste char as alternative green catalysts for oil and metal recovery

Abstract

This paper studied pyrolysis and catalytic reforming processes of ABS/PC and PCB as representatives of e-waste for possibility of energy and metal recovery. Y-Zeolite (YZ), ZSM-5, biochar (BC), electronic waste char (EWC), iron oxide loaded YZ (Fe/YZ), Fe/ZSM-5, Fe/BC and Fe/EWC were used as catalysts. Pyrolysis and catalytic reforming were performed at 500 °C. Results showed that the ABS/PC had high yield of oil (40–75%) whereas PCB showed limit amount of oil yield (lower than 8%). Catalysts increased single-ring hydrocarbon products in pyrolysis oil of both ABS/PC and PCB. Iron oxide originally in BC and EWC had the debromination effect during catalytic reforming process. Maximum debromination performance for ABS/PC and PCB feedstock was 91% (Fe/BC) and 68% (Fe/EWC), respectively. Metal compound in char was significantly high in case of PCB (16.025 wt%) and relatively low from ABS/PC (1.141 wt%). This research showed that using renewable catalyst precursors such as biochar or char from e-waste itself during pyrolysis and catalytic reforming was a promising method to recover low-bromine oil and metal. This could save cost on catalyst and increase possibility for implementation.