Granular activated carbon for the recovery of the main pear aroma compound: Viability and kinetic modelling of ethyl-2,4-decadienoate adsorption

Methyl and ethyl esters of 2,4-decadienoic acids are considered the main responsible compounds for the typical flavour impact of pears. In this work, the adsorption on granular activated carbon (GAC) was the selected method for extracting ethyl-2,4-decadienoate from an aqueous phase, examining the possibility of recovery of this valuable aroma component from the aqueous fruit juice. Equilibrium and kinetic data were obtained in fixed-bed column experiments. The experimental variables under study were the concentration of the ethyl-2,4-decadienoate in the feed solution, in the range 0.20–0.39 mol m−3 and the length of the GAC bed. Equilibrium data were fitted to the Freundlich isotherm, obtaining the characteristic parameters. For the analysis of the kinetic data, a mathematical model accounting for effective pore diffusion was proposed. The value of the intraparticle diffusivity was obtained using an estimation procedure to give Dp∗=2.47×10-9 m2 s−1. This value, higher than the molecular diffusion coefficient indicates an important contribution of surface diffusion to the effective pore diffusivity parameter. Finally, the application of the adsorption model using the estimated value of Dp∗ simulated satisfactorily well the breakthrough curves under the operation conditions.