Abstract

This study investigates the potential of torrefied rubberwood pellets (TWP) as a sustainable biofuel, using waste from southern Thailand's wood processing industry. A multi-criteria framework combining experimental analysis, CO<inf>2</inf> emission, and an Economic Environmental Index (EEI) was employed to optimize torrefaction conditions and evaluate industrial scalability. The optimal conditions were identified to be 288 °C for 30 min, resulting in a volumetric energy density of 16.10 GJ m⁻³ and an eco-efficiency of 0.16 %Y<inf>E</inf> (kg CO<inf>2_eq</inf>/kg biomass)⁻¹ USD⁻¹. This demonstrates a critical balance between energy quality and environmental impact. Compared to conventional wood pellets, torrefaction reduced CO<inf>2</inf> emissions by 27 %. GIS mapping was used to plan regional logistics routes, while scenario analyses demonstrated enhanced profitability (EEI ratio: 2.73) and carbon credit opportunities, reducing 2275 kg CO<inf>2_eq</inf> per ton of coal replaced. The study establishes TWP as a carbon-negative biofuel suitable for power generation and cement production, supporting Thailand's transition to a circular bioeconomy. By bridging technological innovation with regional waste valorization, this research provides a replicable model for sustainable biomass utilization in tropical agro-industrial contexts.