Synthesis of γ-Al2O3 catalyst support from Kaolin of Indonesian origin

Abstract

Kaolin has been identified as a potential raw material for the production of γ-Al2O3 for hydrotreating catalyst support. This work explores the technical feasibility of applying the potassium hydroxide (KOH) extraction synthesis route on kaolin from the Belitung Island in Indonesia. The application of a published synthesis method to Belitung kaolin requires an approximately twofold increase in kaolin calcination time, an increase in kaolin calcinations temperature from 950 to 1000°C, and a tenfold increase in metakaolin extraction time, to obtain a specific surface area higher than 200 m2/g. The highest specific surface area of 233 m2/g was obtained when the kaolin was calcined at 1000°C for 24 hours, and the metakaolin was extracted by concentrated KOH solution for 12 hours. Phase characterization of the final product confirmed the formation of γ-Al2O3, but with the inclusion of low-surface area α-Al2O3 phase.