Solketal Production from Glycerol Ketalization with Acetone: Catalyst Selection and Thermodynamic and Kinetic Reaction Study

In this work, the main results of a thermodynamic and kinetic study of glycerol ketalization to produce solketal in the presence of a solvent are presented. A catalyst and a solvent screening was carried out leading to the selection of Amberlyst-35 ion-exchange resin and ethanol as the most suitable materials for this reaction. A parametric study allowed one to determine reaction equilibrium and kinetic parameters in a batch reactor in the absence of external mass-transfer limitations. Regarding reaction thermodynamic equilibrium, a standard enthalpy of -20.1 +/- 1.1 kJ mol(-1) and a Gibbs free energy of 1.4 +/- 0.3 kJ mol(-1) were obtained. Reaction kinetics was studied assuming different reaction rate laws to fit the experimental data obtained: Pseudo-Homogeneous (PH), Langmuir-Hinshelwood-Hougen-Watson (LHHW), and Eley-Rideal (ER). The experimental results revealed that the reaction kinetics behavior could be accurately described by the LHHW reaction rate law, considering the presence of internal mass-transfer resistances. The activation energy for the overall reaction was found to be 69.0 +/- 6.6 kJ mol(-1).