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

Liquid phase dehydration of glycerol to acrolein catalyzed by Brّnsted 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.