Thermal conversion of organic furniture waste to hydrogen fuel via catalytic air gasification over monolithic spinel-type oxide-supported nickel catalysts

Furniture waste sawdust, as a byproduct of the furniture industry, is discharged in huge amounts annually. However, traditional strategies applied for their treatment have resulted in crucial environmental issues. As an eco-friendly alternative option to treat Furniture waste sawdust, this study developed a catalytic gasification technology using spinel-type oxide (AB₂O₄)-supported Ni catalysts under an air atmosphere to generate H₂-rich gas. To this end, different metals are substituted as A cation in the spinel structure, followed by wash-coating on the monolithic reactor and impregnation with Ni to prepare Ni/MAl₂O₄ (M = Ca, Co, Ba, Zn, Zr, Mg, or Cu) catalysts. The employment of catalysts greatly enhanced the gas yield and H₂ and CO selectivities, while significantly reducing the CO₂, CH₄, and C₂-C₄ generation, attributable to stimulated dry- and steam-methane reforming reactions. In particular, the highest gas yield (81.67 wt%) and H₂ selectivity (32.19 vol%), lowest CO₂, and almost zero CH₄ and C₂-C₄ contents are obtained over Ni/CoAl₂O₄ catalyst, owing to the high oxygen transfer potential, appropriate basicity, and high Ni dispersion. Furthermore, a considerably enhanced gas yield and slightly increased H₂ selectivity are observed when the gasification temperature is increased from 700 to 800 °C, reaching the maximum at 87.31 wt% and 32.87 vol%, respectively. Moreover, different catalyst-to-feedstock ratios from 1/5 to 1/20 gently influenced the gas yield and composition. Overall, the emerging potential of monolithic spinel-type oxide-supported Ni catalysts for hydrocarbon cracking, along with the use of waste materials as feedstock, can open new prospects for the economical and eco-friendly generation of H₂ via gasification technology.”