Preparation of Isoamyl Acetate by High Performance ZSM-5 Zeolite Membrane

Abstract

A high performance ZSM-5 zeolite membrane is applied to remove H₂O from the esterification of acetic acid and isopentanol by pervaporation. The influences of reaction conditions on the isoamyl acetate yield are studied in detail. Compared with the traditional esterification of acetic acid and isopentanol, the esterification with “membrane extractor” has a well isoamyl acetate yield at low reaction temperature. With the reaction temperature, acetic acid/isopentanol molar ratio and effective membrane surface area to esterification mixture ratio volume of 100°C, 3.0/1.0, 2.0 wt% NaHSO₄, and 0.26 cm²/cm³, respectively, the isoamyl acetate yields was 98.39%, the membrane flux and separation factor (H₂O to organic) were 0.21 kg·m⁻²·h⁻¹ and 1040, respectively. Further, the ZSM-5 zeolite membrane shows good long–term stability and reproducibility for the pervaporation-esterification, the isoamyl acetate yields of the esterification-pervaporation for intermittent 8 times or continuous 160 h still remained at 97.73% and 98.30%, respectively. In addition, the ZSM-5 zeolite membrane still retained the typical MFI diffraction peaks and morphology by XRD and SEM characterization after long-term PV–esterification .