Combined valorization of bone waste as feedstock and support material for ex-situ catalytic pyrolysis

This study explores the ex-situ catalytic pyrolysis of chicken wing bones to improve product yield and quality compared to non-catalytic pyrolysis. Novel catalysts were developed from the biochar obtained by pyrolyzing chicken bone waste, primarily composed of hydroxyapatite. The chicken bone biochar (CBB) was further enhanced with ZSM-5 zeolite and cobalt nanoparticles to improve catalytic performance. All catalysts underwent NH₃-TPD, XRD, SEM-EDAX, and BET analyses. Pyrolysis was conducted at 500 °C for 22 min, with the ex-situ catalyst chamber maintained at 400 °C. Catalyst addition reduced liquid yields but increased gas production significantly. The Co/CBB_HZSM5 catalyst generated 8 % H₂ (four times more than the non-catalytic case), 13.5 % CH₄, and nearly 23 % H₂+CO (syngas). Catalysts also enabled diverse reaction pathways, producing a range of valuable chemicals. CBB proved effective for generating ketones, amides, fatty acids, cyclic ureas, lactams, and dicarboximides. CBB_HZSM5 favored ester formation, while Co/CBB_HZSM5 was optimal for producing aromatics, amines, and nitriles. The generated gases have promising energy applications, especially syngas and methane. The bio-oil also showed energy potential, with Co/CBB_HZSM5 yielding a high heating value of 23 MJ/kg, making it a viable biofuel. Overall, this catalytic pyrolysis approach offers a sustainable, circular solution for managing organic waste, transforming it into valuable chemicals and fuels. • Innovative Catalyst: Biochar catalyst support from chicken wing bone waste. • Catalytic Enhancement: Co nanoparticles and HZSM5 boosted gas yields and diversity. • Synthesis: Selective production of esters, aromatics, and ketones. • Energy Potential: Production of syngas and methane for energy applications. • Sustainable Valorization: Circular economy through waste-to-value conversion.