Ethyl levulinate ketalization with glycerol promoted by H,Y-Zeolite: Kinetic analysis in batch and continuous milli-reactor scale

Ketals from levulinic acid are considered emerging compounds which have obtained growing interest in last years. Their possible applications are different, from additives for fuels to plasticizers, polymers and solvents. Ketals can be obtained starting from levulinic acid and its esters. The advantages in using the esters, such as ethyl levulinate, can be found in avoiding the occurrence of the competitive esterification reaction. In this work, the attention was focused on the reaction between ethyl levulinate and glycerol to obtain the five-membered ketal. The reaction was made in the presence of H,Y-zeolite as catalyst investigating the kinetics in batch reactor and in a continuous milli-reactor simulating all the experimental data with a mathematical model. The activation energy was measured both without catalyst (Ea = 104 kJ/mol) and for the catalyzed experiments (Ea = 48 kJ/mol). The reaction showed an endothermic behavior as demonstrated by the reaction enthalpy (ΔrH = 41 kJ/mol). The feasibility of the operation in flow was demonstrated using a milli-reactor. From data interpretation, the fluid– solid mass transfer coefficient was calculated for each volumetric flow. The present study tracks the basis for a future scale-up of the process.