Direct esterification in helical continuous-flow microreactors under an aqueous environment: optimization, reaction kinetics, and process intensification

Abstract

This study presents an optimized process for producing long-chain alkyl acrylates via direct esterification in a helical continuous-flow microreactor. Addressing the inefficiencies of traditional batch esterification, such as low energy efficiency and slow mass transfer, this method utilizes continuous-flow chemistry for more effective, eco-friendly, and cost-efficient production. The microreactor, with a 10 m long and 0.5 mm diameter helical microchannel, which active volume was 3.925 ml, was examined for its performance influenced by reactant-catalyst ratios, temperature, and residence time. Results show significantly improved yields of myristyl acrylate (over 89 % in 300 s, respectively) while the residence time was 300 s at 110 ± 10 °C, with a molar ratio of 1-tetradecanol to acrylic acid of 1.3 and a catalyst to acrylic acid molar ratio of 0.1. Additionally, a second-order reaction kinetic model was developed to better understand the reaction dynamics in this setup. This research underscores the potential of integrating helical continuous flow with esterification, offering a novel approach to studying these mechanisms.