Optimization of Sulfonated Carbon Catalyst Synthesis Based on Cocoa Pod Husk (Theobroma Cacao) Waste from Papua for Enhanced Biodiesel Conversion

The increasing dependence on fossil fuels in Indonesia presents significant challenges in terms of energy security, economic resilience, and environmental sustainability. As a renewable energy source, biodiesel offers a promising alternative; however, its production efficiency relies heavily on the use of low-cost, effective, and eco-friendly catalysts. This study focuses on the development of sulfonated activated carbon catalysts derived from cocoa pod husks (AC-۲۵), an abundant agricultural by-product in Papua, for biodiesel synthesis. Cocoa pod husks were dried at ۱۰۵ °C, carbonized at ۵۵۰ °C, chemically activated with phosphoric acid (۲۰ and ۳۰ %), and subsequently sulfonated using concentrated sulfuric acid. The catalysts were characterized using BET surface area analysis, FTIR spectroscopy, and SEM imaging. BET analysis showed a substantial surface area increase from raw carbon AC-۲۵ (۳۰.۰۸ m۲/g) to ۳۰۴.۷۸ m۲/g and ۴۱۲.۷۷ m۲/g for catalysts activated with ۲۰ % and ۳۰ % H۳PO۴, respectively. FTIR confirmed the presence of phosphate and sulfonic groups, while SEM revealed a transformation from compact to porous morphology. Catalyst performance, evaluated through transesterification of waste cooking oil with methanol, demonstrated that both catalysts produced biodiesel meeting SNI ۷۱۸۲:۲۰۱۵ standards. GC–MS analysis identified methyl palmitate and methyl oleate as dominant FAME components, with the ۳۰ % catalyst yielding a simpler and purer composition (≈۱۰۰ % total FAME) compared to the ۲۰ % catalyst. These results align with previous studies reporting enhanced activity with higher sulfonation levels and confirm the potential of cocoa pod husk waste as a sustainable precursor for high-performance solid acid catalysts in biodiesel production.

کلیدواژه ها:

Agricultural waste valorisation ، Cocoa pod husk ، Sulfonated activated carbon ، Biodiesel production ، Renewable Energy