Chicken meat and bone meal valorization by hydrothermal treatment and anaerobic digestion: Biofuel production and nutrient recovery

• DOI: 10.1016/j.renene.2023.01.005
• Publication Date: 2023-01-03T13:30:30Z
• Authors: A. Sarrion; R.P. Ipiales; M.A. de la Rubia; A.F. Mohedano; E. Diaz
• Keywords: Struvite; Biogas; Digestate; Bone meal

In this work, chicken meat and bones (C-MBM) waste is treated through a sequence of stages including hydrothermal treatment (HTT), nutrient recovery anaerobic digestion, with the aim evaluating their potential synergy as circular economy approach. HTT was carried out at 170, 200 230 °C, under non-acidic acidic conditions using 0.5 M HCl (HTT-A). Phosphorous from process water recovered by chemical precipitation addition Mg salt, liquid effluent anaerobically to degrade organic matter produce methane-rich biogas. Hydrochar obtained presented poor combustion characteristics, while HTT-A yielded bio-oil high higher heating value (≈38 MJ/kg), good combustibility performance reactivity. More than 95% phosphorous (as phosphate) almost 100% nitrogen (being 30% NH4–N) content in C-MBM were solubilized upon HTT-A, these nutrients mainly retained hydrochar reactions. Chemical P NH4–N allowed recovering crystalline solid identified struvite struvite-apatite mixture, negligible heavy metals content. High methane production (250–300 mL CH4/g CODadded) removal (up 75%) achieved tests. proves be suitable for material energetic valorization C-MBM, within framework, which allows obtain value-added products (hydrochar/bio-oil, biofertilizers biogas).