Intraparticle diffusion model to determine the intrinsic kinetics of ethyl levulinate synthesis promoted by Amberlyst-15

Levulinic acid and its esters are considered very versatile chemical compounds used for a wide range of derivatives. Traditionally ethyl levulinate is synthesized in batch reactors, using homogeneous catalysts (H₂SO₄, H₃PO₄). Several investigations were reported on solid acid catalysts, as zeolites, sulfated oxides, sulfonic ion-exchange resins. Amberlyst-15 showed high potentials: to design a continuous reactor, it is necessary to investigate the stability of the catalyst and the kinetics of the reaction. In the present work, we demonstrated that the resin is stable for more than 5 days. Kinetic and mass transfer phenomena were studied, evaluating the partition and take-up of the used resin when put in contact with reactants and products. Two different samples of Amberlyst-15 were used, characterized by different size, demonstrating that bigger particles lead to higher intraparticle diffusion limitations.