ALUMINOSILICATE SYNTHESIZED FROM Cyclotella striata SILICA AS A CATALYST FOR SYNTHESIS OF ETHYL TERT-BUTYL ETHER

• Main Author: LAELALUGINA (NIM:20516045), AMILA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25451
• Institution: Institut Teknologi Bandung

The availability of seawater and sunlight in Indonesia supports the growth of marine <br /> <br /> microorganism called diatom. Diatoms possess unique silica cell walls with diverse cell <br /> <br /> morphologies. Many modified diatomaceous silica has been performed for various applications <br /> <br /> such as biosensors, solar cells, and drug delivery materials. However, the application of <br /> <br /> diatomaceous silica as a catalyst to synthesize ETBE has not been reported yet. In this research, <br /> <br /> silica obtained from Cyclotella striata strain TBI was converted into aluminosilicate and then <br /> <br /> used to catalyze ETBE synthesis. The steps of the present research included cultivation of C. <br /> <br /> striata cells using Batch method, isolation of C. striata silica, aluminosilicate synthesis at low <br /> <br /> temperature, aluminosilicate transformation into acid catalyst through protonation, and <br /> <br /> determination of catalytic activity of aluminosilicate for ETBE synthesis. C. striata cells <br /> <br /> cultivated with initial cell density 2×105 cells/mL for 15 d had a cylinder in shape with a <br /> <br /> diameter 8–20 &#956;m and its biomass density of 1.25±0.28 g/L. The silica content in dried C. striata <br /> <br /> biomass analyzed by TGA was 40% (w/w). The percentage of purified C. striata silica confirmed <br /> <br /> by XRF was 100%. After C. striata silica transformed, vibration bands of Si-O-Al in <br /> <br /> aluminosilicate molecule were identified at wave numbers of 1231 and 553 cm–1. The <br /> <br /> aluminosilicate molecules were crystalline that similar to ZSM-5. The aluminosilicate crystals <br /> <br /> were sphere in shape with a diameter range of 0.6–1.7 &#956;m. The activated aluminosilicate <br /> <br /> converted ethanol and tert-butanol into ETBE as a main product. The highest amount of ETBE is <br /> <br /> obtained at 70 oC. The results showed that aluminosilicate synthesized from the C. striata silica <br /> <br /> was a promising catalyst for ETBE synthesis.