Worldwide, the waste generated by the food industry sector is expected to increase due to demographic extension and consumer-driven society effect. One type of this waste is represented by animal bone. This study explores the valorization of biochar obtained from chicken bone waste (CBW) pyrolysis at 500–700 °C. The biochar obtained at 700 °C showed better characteristics, such as higher porosity, specific surface area and dielectric proprieties. Further on, the biochar was activated through microwave (MW) treatment to improve its structure and morphology. The activated biochar was investigated as microwave susceptor material and catalyst support for microwave-assisted pyrolysis of low-density polyethylene (LDPE) packaging waste. Compared to common microwave susceptors, the activated biochar proved good microwave absorption capabilities, reaching temperatures of 450 °C. Additionally, the biochar was used as catalyst support, doped with silicon, titanium, and zinc oxides with applications in plastic pyrolysis. As catalyst in microwave-assisted pyrolysis (MAP) of LDPE, it enhanced the gas yield of the process, obtaining a pyro-gas composition rich in hydrogen (43%). These findings prove the dual functionality of the CBW-derived biochar, providing a new sustainable solution for converting chicken bone and plastic waste into value-added products. Graphical abstract