Synthesis and Characterization of Biosilica from Rice Husks as a Catalyst for the Production of Biodiesel

The synthesis of silica particles from rice husk is a research based on natural materials and is classified as green material. Preparation of biosilica catalyst from calcined rice husk ash was carried out by the hydrothermal method using rice husk ash mixed with NaOH solution at a ratio of 1:5 (w/v) with the reaction temperature of 110-120°C, the pressure of 0.15-0.2 MPa for 15-30 minutes. Biosilica results are then continued with the calcination process at a temperature of 200-500°C for one hour. Biosilica with calcination is then compared to biosilica without calcination. These two kinds of biosilica are then characterized to determine their performance. The biosilica characteristic test that was carried out included X-Ray Fluorescence (XRF), Scanning Electron Microscopy(SEM), and Brunauer-Emmett-Teller (BET). The XRF test results show that biosilica with calcination process has higher silica and silica oxide content than that without calcination. The surface morphology of biosilica with calcination and without calcination gives an uneven surface and consists of lumps and with uneven distribution on the surface of the biosilica sample. Biosilica with calcination process has a larger surface area, pore volume, and radius than biosilica without calcination process.