SILICA EXTRACTION FROM SUGARCANE BAGASSE AS PRECURSOR IN ANALCIME ZEOLITE SYNTHESIS

• Main Author: Juwita Sari, Aisyah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/33935
• Institution: Institut Teknologi Bandung

Pure analcime (ANA) zeolite was synthesized by using natural silica from sugarcane bagasse ash with hydrothermal method. Zeolites are crystalline aluminosilicate material which has pores in the micro size (< 2 nm). One of the natural zeolite which has much applications in the industrial field is analcime (ANA). Analcime, widely used as absorbents, is effective in water purification and heterogeneous catalysts in various chemical reactions. Even, it has been used in the development of nanoelectronic technology. Although it is a natural zeolite, analcime was found in certain regions in the America, Europe, and Australia. There is no natural analcime exist in Indonesia. Therefore, the synthesis analcime zeolite is important to be able to do. Generally, analcime synthesis uses commercial silica precursors such as fumed silica, Ludox and tetraethyl ortho silicate (TEOS). Besides commercial silica, natural silica from biomass waste can became a sources for zeolite synthesis. One of biomass waste with high silica content is sugarcane bagasse (SCB), resulting from the sugar and ethanol industry. Burning sugarcane bagasse produces sugarcane bagasse ash (SCBA) which is known containing silica about 50-70% by weight. The high silica in sugarcane bagasse ash can be used as silica source in synthesis low cost of analcime. In addition, this process can be one of the solution to manage the waste product of sugar industry. Sugarcane bagasse ash has been obtained from burning processes of bagasse with variation temperature 300, 350, 400, 450, 500 and 600 °C. Silica was extracted by using NaOH solution. In silica polymerization step, we treated the variation of pH (4, 5, and 6) to obtain a high percentage of silica yield. The highest percentage of silica yield (5.76%) was produced in 600 °C and pH 6. The analysis of silica by using X-ray fluorescence (XRF) has got the data of SiO2 and Al2O3, 69 089% and 29.171% respectively. Characterization by X-Ray Diffraction (XRD) showed that the silica is in crystalline phases ?-quartz and cristoballite. Scanning Electron Microscope (SEM) showed the morphology of the resulting silica was spherical shape with particle size about 80 nm. Analcime zeolite synthesis was prepared by hydrothermal method at 170 °C for 72 hours with the following molar composition precursor; 1 SiO2: 0,248 Al2O3 : 0.229 NaOH: 0.24 TPA- Br: 30H2O. The pure analcime phase without impurities was confirmed by XRD data. Furthermore, SEM images showed irregular morphology trapezohedral with particle size about 80 µm. We also synthesized zeolites using commercial silica source, Cab-O-Sil (fumed silica) with the same molar ratio of precursors with the previours work. Synthesis by using Cab-O-Sil was carried out with TPA-Br (as Zeolite 1), absence of TPA-Br (as Zeolite 2), and absence of alumina (as Zeolite 3). The aim of difference treatment in Zeolite 1 and 2 was to investigate the effect of TPA-Br as organic template. In the first treatment, has been found mordenite (MOR) framework and small quantities of MFI. While the second treatment only MOR frameworkwas found. The purpose of the last treatment was to investigate the effect of alumina existence, and MFI framework was found in this treatment. The effect of the silica source in zeolite synthesized, was studying by comparing analcime zeolite and Zeolite I. Silica from sugarcane bagasse ash which contain crystalline, a-quartz and cristobalite, is directed to the formation of ANA zeolite.