Life Cycle Assessment of Biodiesel Production from Dipterocarpus alatus Oleoresin Using Potassium-Loaded Zeolite Y Catalyst Derived from Rice Husk Silica

This study investigates the life cycle and catalytic performance of biodiesel production from Dipterocarpus alatus oleoresin using a heterogeneous base catalyst derived from potassium-loaded Zeolite Y synthesized from rice husk silica (K/NaY). The catalyst was prepared via wet impregnation of KOH onto NaY, followed by calcination at 550 °C for 4 h to ensure potassium dispersion and framework stability. Transesterification was performed under optimized conditions at a methanol-to-oil molar ratio of 16:1, 3 wt% catalyst loading, and 60 °C for 90 min. The maximum biodiesel yield achieved was 96.7%, while the catalyst maintained above 80% yield after four successive reuse cycles, demonstrating excellent reusability. Fuel characterization by thin-layer chromatography (TLC) and gas chromatography with flame ionization detection (GC-FID) revealed that methyl oleate and methyl palmitate were the dominant components, meeting key specifications of ASTM D6751 and EN 14214 standards. A cradle-to-gate life cycle assessment (LCA) was conducted using a functional unit of 1 MJ biodiesel, applying the ReCiPe 2016 midpoint methodology with SimaPro v9.3 software. Results showed a global warming potential (GWP) of 0.027 kg CO₂-eq/MJ, substantially lower than fossil diesel (0.094 kg CO₂-eq/MJ). Overall, the findings confirm both the catalytic efficiency and environmental sustainability of K/NaY catalysts derived from rice husk, highlighting their potential for scalable industrial biodiesel applications.