Sintesis dan Karakterisasi Serbuk Bunga Sepatu dan Karbon Aktif Kayu Ulin sebagai Prekursor Katalis Pirolisis Plastik

Abstract

Plastic waste pyrolysis requires catalysts that are thermally stable, accessible, and economically viable. This study synthesizes and characterizes a biomass-based catalytic material derived from hibiscus flower powder and activated Ulin wood carbon. Hibiscus petals were dried under sunlight for 6 h, oven-dried at 55 °C for 1 h, ground, and sieved to 200 mesh. Ulin wood carbon was reduced by high-energy milling, sieved to 200 mesh, activated in 3 M NaOH using 8 g carbon for 12 h, washed to pH 6–7, and dried at 105 °C for 8 h. UV–Vis analysis showed that hibiscus powder contained 676.62 mg EQ/100 g flavonoids, 2305.06 mg GAE/100 g phenols, 369.69 ppm antioxidant activity, and 122.40 ppm anthocyanins. Activated Ulin carbon contained 166.28 mg EQ/100 g flavonoids, 32.04 mg GAE/100 g phenols, 0 ppm antioxidant activity, and 0.54 ppm anthocyanins. Thermal, morphological, functional group, and crystallinity analyses were conducted using TGA-DTA, SEM, FTIR, and XRD. The results indicate that hibiscus contributes oxygenated bioactive compounds, whereas activated Ulin carbon provides a carbonaceous support structure. The combined characteristics suggest potential use as a sustainable catalyst precursor for plastic waste pyrolysis.

Keywords: Hibiscus flower; ulin wood carbon; activated carbon; biomass catalyst; plastic waste pyrolysis