Characteristics of syngas and biochar from wood-based waste furniture gasified in a one-tonne-scale mobile high-temperature gasification system

• One-tonne-scale mobile downdraft gasification of waste wooden furniture demonstrated. • Three-stage cleaning; oil–water separator shows highest impurity removal. • 25% feedstock moisture yields highest LHV; moisture dominates syngas quality. • Raising 850–1050 °C increases biochar surface area, pore volume, and defects. • Mobile gasification of furniture waste cuts CO2 via syngas use and biochar storage. The disposal of wood-based waste furniture presents significant environmental and waste management challenges. In this study, a downdraft high-temperature gasifier equipped with a three-stage impurity removal system is used to convert one metric ton wood-based waste furniture into syngas and biochar. Among the three stages of impurity removal, the oil–water separator demonstrates the highest effectiveness. The syngas composition and its lower heating value (LHV) show slight variation across all impurity removal stages. In contrast, feedstock moisture content is found to critically influence syngas quality. In our work, 25 % moisture content is identified as the optimal condition for producing syngas with the highest LHV. The results indicate that feedstock moisture content has a greater impact on syngas quality than impurity removal. A temperature-dependent porous structure is observed in biochar. As gasification temperature increases from 850 to 1050 °C, specific surface area, total pore volume, and defect density increase. The reduction of CO 2 emissions through syngas (as a fossil fuel substitute), biochar (via carbon sequestration), and the mobile system (eliminating the need for gathering or transportation) indicates that high-temperature gasification is an environmentally friendly method for furniture disposal.