| Abstrakt: |
The advantages offered by biomass-based heterogeneous catalysts, such as being easily separated from reaction products, being used many times, having low production costs, and being widely available in nature. One of the heterogeneous catalysts that can be used is a sodium silicate catalyst, especially one obtained by impregnating Na metal on a SiO2 matrix derived from biomass ash. In this study, palm leaves have the potential to be used as raw material for the SiO2 matrix because their utilization has yet to be optimal. This research aims to synthesize, characterize, and apply a sodium silicate catalyst based on palm leaves ash in the production of biodiesel from Refined, Bleached, Deodorized, Palm Oil (RBDPO). SiO2 was obtained by calcining palm leaves at a temperature of 700 °C for 3 hours, followed by washing using 1 N HCl solution. In this research, variations in the mole ratio of NaOH: SiO² were carried out in the synthesis of sodium silicate, namely 1:1, 1.5:1, 2:1, and 2.5:1. This research also evaluates the reusability of the sodium silicate catalyst and the effect of washing using methanol on the biodiesel yield produced. The best sodium silicate catalyst was obtained at a NaOH: SiO2 molar ratio of 1.5:1, with a biodiesel yield of 74.485 % and an ester content of 97.293 %. SEM analysis shows the presence of a porous structure on the catalyst. The existence of the Si-O-Na group has been confirmed using FTIR. BET-BJH analysis has confirmed the presence of a mesoporous structure in the catalyst, with a surface area of 6.4343 m²/g and a pore size of 5.3127 nm. The resulting sodium silicate catalyst can be used up to three times, with a yield of 62.388 %. Catalyst regeneration using methanol is capable of producing biodiesel with a yield of 45.198 %. [ABSTRACT FROM AUTHOR] |
