Liquid phase catalytic dehydration of glycerol to acrolein over Brønsted acidic ionic liquid catalysts

Abstract

Liquid phase dehydration of glycerol to acrolein catalyzed by Brønsted acidic ionic liquids (BAILs) using semi-batch reaction technique was investigated. For the BAILs catalysts, the acrolein yields were in an order of [Bmim]H2PO4>[Bmim]HSO4>[BPy]HSO4>[PSPy]HSO4>[N2224]HSO4>[PSPy]H2PO4>[BPy]H2PO4>[N2224]H2PO4. When [Bmim]H2PO4 and [Bmim]HSO4 were used as the catalysts at 270°C with the molar ratio of catalyst to glycerol of 1:100, the acrolein yields were 57.4% and 50.8%, respectively, at complete conversion of glycerol. The BAILs with [Bmim] cation and moderate acidity favored the formation of acrolein in liquid phase glycerol dehydration.