Hydrogen Production from Solid Food Waste by Combined Hydrothermal Pretreatment and Aqueous-Phase Catalytic Reforming

Production of sustainable hydrogen will play a key role as the main energy vector for the transition to a decarbonized economy. Of particular interest is the conversion of biomass into hydrogen, adding value to streams that would otherwise go unused. This study demonstrates efficient hydrogen production from orange juice extraction waste using hydrothermal pretreatment and aqueous-phase reforming. Key parameters─temperature, time, initial pH, and biomass concentration─were optimized using Pt-based catalysts (3–5 wt %) on carbon black with enhanced stability. The highest hydrogen yields were achieved under mild hydrothermal conditions (100–120 °C, 1 h), with ca. 1.0 g/L initial total organic carbon (TOCo) and pH 4. Increasing Pt loading not only improved the hydrogen yield but also increased catalyst deactivation. Under optimal conditions, 84% TOC conversion, 77% carbon conversion to gas, and 69 mmol H₂/gTOCo were obtained, with hydrogen comprising 54% of the product gas. This integrated approach is promising for converting agroindustrial residues into clean hydrogen.