Conversion Gibbsite to Boehmite as Raw Material for ????-Alumina Support

• Main Author: Calvin
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/38475
• Institution: Institut Teknologi Bandung

Gamma (?) alumina is the most commonly used type of catalyst support. It can only be synthesized from boehmite, while Indonesia is rich in gibbsite. Gibbsite can be converted to boehmite, so ?-alumina has the opportunity to be synthesized from Indonesia’s gibbsite. Therefore, further research and development on gibbsite conversion technology into boehmite is needed to optimize Indonesia's gibbsite potential and reduce our dependence on imported boehmite. In this study, synthesis of boehmite from gibbsite was carried out by hydrothermal method. In this method, water and alkali can be used as a reaction media. Variations of experiment that have been done are heating temperatures at 150°C, 175°C, and 200°C; heating time in 2,5 hours, 5 hours, and 8 hours; NaOH and KOH concentration of 1.5 M and 3 M. Characteristics of the result, such as crystallinity and peak amounts then analyzed using XRD analysis. Samples that have crystallinity and peaks amount similar to commercial boehmite (Catapal) are then analyzed further using BET to determine the surface area, pore volume, and diameter of the pores. Furthermore, boehmite product and commercial are synthesized further to ?-alumina support and the results are analyzed using BET to compare the characteristics that obtained. Synthesis of boehmite from gibbsite with the best characteristics in terms of crystallinity and peak numbers was obtained at heating temperature of 175°C and a heating time in 5 hours with NaOH and KOH as the reaction medium. Boehmite product has a percent crystallinity of 52,4%-53,1%; XRD peak numbers 21-24; pore diameter 0,0225-0,0248 ?m; surface area 26,4 m2/g-41,1 m2/g; and pore volume 0,06-0,1 cm3/g. The synthesized supports from boehmite have a surface area of 68,6-84,1 m2/g and pore volume of 0,17-0,19 cm3/g which is still smaller compared to the support that synthesized from Catapal boehmite and boehmite CHALCO. In addition, the synthesized boehmite has not succeeded in forming a gel in the sol-gel method.