Chromatographic reactors: Esterification of glycerol with acetic acid using acidic polymeric resins

Reactive chromatography is an attractive method for chemical synthesis because chemical reactions and product separation occur simultaneously in the same unit. In this work, the synthesis of triacetine, starting from glycerol and acetic acid, using reactive chromatography on acidic polymeric resins is investigated. The study proceeds first to the characterization of the adsorption equilibria of the involved multicomponent mixtures and then to the study of the kinetics of the relevant reactions using a batch reactor. Next, the separation-reaction process is investigated using a fixed-bed chromatographic column. The obtained data are compared with the predictions of a mathematical model, whose kinetic and equilibrium parameters were estimated from the batch experiments mentioned above. It is shown that, although this synthesis requires three steps in series, the chromatographic reactor can produce high-purity (i.e., food-grade) triacetine with high conversions. It is found that the presence of water in the resin at the end of the regeneration step has a strongly detrimental effect on the final triacetine purity.