Synthesis of -Al2O3 Catalyst Support from Kaolin of Indonesian Origin

Abstract

Abstract. Kaolin has been identified as a potential raw material for the production of -Al 2 O 3 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 calcination temperature from 950 to 1000 o C, and a tenfold increase in metakaolin extraction time, to obtain a specific surface area higher than 200 m 2 /g. The highest specific surface area of 233 m 2 /g was obtained when the kaolin was calcined at 1000 o 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 -Al 2 O 3 , but with the inclusion of low-surface area -Al 2 O 3 phase.

A new samarium complex of 1,3-bis(pyridin-3-ylmethyl)thiourea on boehmite nanoparticles as a practical and recyclable nanocatalyst for the selective synthesis of tetrazoles

“…In fact, boehmite is aluminum oxide hydroxide (γ-AlOOH), which is the most stable alumina phase in nature after gibbsite [12][13][14][15] . Moreover, boehmite turns into γ-Al 2 O 3 , δ-Al 2 O 3 , θ-Al 2 O 3 , and α-Al 2 O 3 at temperatures of 450 °C, 900 °C, 1000 °C, and 1200 °C, respectively 16 .…”

“…In fact, boehmite is aluminum oxide hydroxide (γ-AlOOH), which is the most stable alumina phase in nature after gibbsite [12][13][14][15] . Moreover, boehmite turns into γ-Al 2 O 3 , δ-Al 2 O 3 , θ-Al 2 O 3 , and α-Al 2 O 3 at temperatures of 450 °C, 900 °C, 1000 °C, and 1200 °C, respectively 16 .Nowadays, it is accepted that boehmite consists of double layers of octahedron structure from oxygen and a central aluminum atom with a cubic orthorhombic unit cell in which aluminum is surrounded by six oxygen atoms [17][18][19] . The two layers are connected via hydrogen bonds 20 .…”