Sorption enhanced reactive process for the synthesis of glycerol ethyl acetal

Abstract

The synthesis of glycerol ethyl acetal via acetalisation of glycerol with acetaldehyde, using dimethyl sulfoxide as solvent, in a fixed bed adsorptive reactor packed with Amberlyst-15 wet, operated isothermally at 303 K, was investigated. The study comprised the determination of fundamental adsorption equilibrium data, performing several breakthrough experiments with non-reactive pairs of the species involved in the synthesis of the acetal and fitting the results by Langmuir competitive isotherms. The response of the fixed bed to reactive mixtures was also analysed demonstrating that a conversion of approximately 79% could be achieved at the steady state when an equimolar mixture of acetaldehyde, glycerol and dimethyl sulfoxide was fed to the reactor at 5.0 mL min(-1). Additionally, considering the adsorption data gathered, and accounting for the reaction kinetics, the effects of the dispersive plug flow, the velocity variations due to the changes of the bulk composition and the internal and external mass transfer mechanisms, it was possible to develop a mathematical model that could effectively describe the dynamic behaviour of a fixed bed adsorptive reactor applied to the synthesis of glycerol ethyl acetal.