Equilibrium thermodynamics and mass transfer parameters estimation of the products of synthesis of piperonal by high performance liquid chromatography

Resumo

The reaction sequences applied to essential oil of Piper hispidinervum D.C (long pepper) leads to formation of a multicomponent mixture composed, mainly, by piperonal, safrole, isosafrole and terpinolene. Due to importance of the piperonal for the pharmaceutical industry is that proposed separate it by high performance liquid chromatography. In this paper, it was studied the adsorption and mass transfer phenomena of these compounds using ethanol/water 70/30 (v/v) as mobile phase and C₁₈ as stationary phase at 35 ^oC. Regarding to adsorption, the piperonal is the component that has the lowest affinity and terpinolene, the greatest with stationary phase. Regarding to mass transfer, effective diffusion and axial dispersion coefficients were around 10^{- (10 to 11)} and 10^{- (7 to 8)} m².s^-1, respectively. The internal resistance to mass transfer controls the overall mass transfer and parallel diffusion model describes the intra-particle transport mechanism.