Optimized Co‐Gasification of Industrial Sludge and Waste Wood Pellets Using Reduced Slag as Bed Material in a Fluidized Bed Reactor

This study presented an innovative co‐gasification approach using industrial sludge (IS) and waste wood pellets (WP)—two common industrial wastes—within a bubbling fluidized bed reactor. Additionally, reduced slag, a Ca‐ and Mg‐rich byproduct of blast furnace operations, was used as the bed material, effectively preventing bed agglomeration commonly induced by alkali metals released during IS gasification. The synergistic behavior between IS and WP was confirmed by thermogravimetric and FTIR analyses, with a 20% WP blend enhancing pyrolysis performance and a 60% WP blend achieving the lowest activation energy (62.67 kJ/mol). Air–steam gasification conditions were optimized using the Taguchi method to maximize system performance under varying objectives. Key parameters included sludge blending ratio (BR), equivalence ratio (ER), steam‐to‐biomass ratio (S/B), and catalyst loading. Optimal operational conditions were identified, resulting in hydrogen concentration of 12.61%, CO concentration of 20.49%, H 2 /CO ratio of 0.82, cold gas efficiency (CGE) of 44.85%, and an exergy efficiency of 32.91%. These findings not only demonstrate the technical feasibility and substantial potential of converting difficult‐to‐treat IS into clean and valuable energy sources but also offer practical guidance for future industrial‐scale applications and the advancement of waste‐to‐energy technologies.