A Comparative Study of Different Al-based Solid Acid Catalysts for Catalytic Dehydration of Ethanol

Abstract

In this present study, the catalytic dehydration of ethanol over three different Al-based solid acid catalysts including H-beta zeolite (HBZ), modified H-beta zeolite with γ-Al₂O₃ (Al-HBZ) and mixed γ-χ phase of Al₂O₃ (M-Al) catalysts was investigated. The ethanol dehydration reaction was performed at temperature range of 200 to 400^oC. It revealed that all catalysts exhibited higher ethanol conversion with increased temperatures. At low temperatures (ca. 200 to 250^oC), diethyl ether (DEE) was obtained as a major product for all catalysts. However, with increased temperatures (ca. 300 to 400^oC), ethylene was a major product. Among all catalysts, HBZ exhibited the highest ethanol conversion giving the ethylene yield of 99.4% at 400^oC. This can be attributed to the largest amount of weak acid sites present in HBZ, which is related to the Brønsted acid. It should be mentioned that HBZ also rendered the highest yield of DEE (ca. 35.3%) at 250^oC. As the results, HBZ catalyst is promising to produce ethylene and DEE from ethanol, which is considered as cleaner technology.