DEVELOPMENT OF PRODUCTION OF HYDROTREATING CATALYST SUPPORTS FROM INDONESIAN MINERAL SOURCES: TRANSFORMATION OF GIBBSITE INTO BOEHMITE

• Main Author: Zahra Ustaqien, Alika
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82024
• Institution: Institut Teknologi Bandung

Indonesia is rich in bauxite ore resources, with around 1,000 million metric tons of reserves, ranking sixth globally in terms of bauxite reserves and ore production. This abundance presents an excellent opportunity for the country to meet the growing demand for high-quality catalyst supports like gamma alumina. However, the majority of the alumina found in Indonesia is still in the form of gibbsite, which cannot be directly transformed into gamma alumina. Thus, the gibbsite extracted from bauxite must undergo a process of transformation into boehmite crystals before it can be synthesized into gamma alumina. The conversion of gibbsite to boehmite was successfully achieved through the hydrothermal method. Various operating conditions were explored to determine the optimal operating conditions for producing boehmite with quality comparable to commercial boehmite. Parameters investigated include reaction time (3, 4, 5, and 6 hours), reaction temperature (170, 180, 190, and 200°C), HNO3 concentration (3, 5, 7, and 9 M), and the addition of commercial boehmite seeds (0.5, 1.0, 1.5, and 2%). The synthesized gamma alumina and boehmite underwent characterization using X-ray diffraction to determine crystallinity and peak positions. Additionally, the surface area and pore volume were analyzed using Nitrogen-Sorption. The optimum operating conditions, resulting in the best boehmite characteristics, were identified as utilizing a 5 M HNO3 solution with 1% boehmite seeds, operating at 170°C for 5 hours. Under these conditions, a yield of 91.62%, with a surface area of 241 m2/g and a pore volume of 0.26 cm3/g, was achieved. The optimal sample, C122, was used to synthesize gamma alumina via the sol-gel method. Sample C122 successfully served as a precursor for gamma alumina production. The resulting gamma alumina, labelled GA- 2, exhibited a surface area of 181 m2/g and a pore volume of 0.29 cm3/g.