A comparative study on the synthesis of ethyl propionate in a pervaporation membrane reactor

Abstract

In this study, esterification of propionic acid with ethanol over a tungstophosphoric acid catalyst was conducted in a batch reactor and in a pervaporation membrane reactor (MR). The performance of the esterification was determined in terms of the propionic acid conversion. Effects of the reaction temperature within the range of 50 °C–70 °C, the initial molar ratio of reactants (1:1, 2:1, 3:1), and the catalyst concentration (10–20 g cat/kg reactant) on the propionic acid conversion were investigated. A poly(vinyl alcohol) membrane was prepared and used to remove the water from the reaction media simultaneously. Conversion results of the batch reactor (BR) and the MR were compared. Results showed that the conversion of the reaction was improved by using MR. As the highest conversion of 80.7% was obtained in the BR, 92.9% of acid conversion was achieved in the MR at 70 °C when the alcohol:acid molar ratio was 3:1. The conversion of the propionic acid-ethanol esterification was enhanced between the values from 15% to 27% by using MR. Activation energy of the reaction carried out in the MR was found as 39.6 kJ/mol.