Energy and material recovery from bone waste: Steam gasification for biochar and syngas production in a circular economy framework

The food industry generates large amounts of bone waste, which presents both environmental and economic challenges. This study investigates the potential of bone waste as a feedstock for the production of energy carriers (syngas) and biochar through steam gasification, contributing to sustainable energy and circular economy strategies. The raw feedstock characterised by low carbon (<20 %) and high ash content (with large amounts of Ca and P) was subjected to steam gasification at 800 °C, 900 °C and 1000 °C to obtain the biochar developed at the surface. Biochar generated at 800 °C exhibited the highest surface area and micropore volume, making it ideal for catalysis or energy storage purposes. This biochar was then applied to the Py-GC-MS of biomass to investigate its catalytic properties. Kinetic analysis using isoconversional methods revealed that the addition of bone-derived biochar to biomass reduced the apparent activation energy in the primary devolatilization stage, facilitating a more efficient conversion process. These findings highlight the feasibility of using bone waste as a resource for the development of advanced biofuels and catalysts, aligning with the sustainability goals and waste valorisation principles.