Synthesis of geranyl acetate by esterification of geraniol with acetic anhydride through heterogeneous catalysis using ion exchange resin

This work aims to synthesize geranyl acetate through heterogeneous catalysis using the ion exchange resin Lewatit (R) GF 101 from the geraniol esterification reaction with acetic anhydride. The reaction was monitored by gas chromatography and the chemical structure of geranyl acetate was confirmed by mass spectrometry and nuclear magnetic resonance spectroscopy. Fourier transform infrared spectroscopy confirmed the sulfonic group responsible for the catalysis. The optimal experimental condition for geranyl acetate synthesis (temperature at 40 degrees C, catalyst content at 7% wt and molar ratio of geraniol to acetic anhydride at 1:4) was obtained from an experimental design analysis. The reaction showed the highest combined values for geraniol conversion (98.28%) and selectivity to geranyl acetate (96.48%). The complete geraniol conversion was achieved at 70 min of reaction with 95.94% selectivity. The value obtained for the main reaction kinetic constant was 31 times greater than that of the secondary reaction found by pseudo-homogeneous model. Furthermore, the reaction rate was controlled only by the geraniol decay, an expected behavior due to the excess of acetic anhydride used. The catalyst reuse was investigated and after 3 cycles a low loss of the catalytic activity was observed, maintaining high conversion (94.43%) and selectivity (97.19%). (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study focuses on synthesizing geranyl acetate using the ion exchange resin Lewatit (R) GF 101 and achieved optimal experimental conditions for high selectivity and conversion rates. The reaction kinetics revealed a significant difference between the main and secondary reactions, and the catalyst showed good reusability with minimal loss of activity after multiple cycles.