Lipase-catalyzed synthesis of isoamyl acetate in an ionic liquid/n–heptane two-phase system at the microreactor scale

Abstract

A continuously operated ψ-shaped microreactor was used for lipase-catalyzed synthesis of isoamyl acetate in the 1-butyl-3-methylpyridinium dicyanamide/n-heptane two-phase system. The chosen solvent system with dissolved Candida antarctica lipase B, which was attached to the ionic liquid/n-heptane interfacial area due to its amphiphilic properties, was shown to be highly efficient and enabled simultaneous esterification and product removal. At preliminarily selected conditions regarding the type of acyl donor, its molar ratio to alcohol and enzyme concentration, 48.4 g m⁻³ s⁻¹ of isoamyl acetate was produced, which was almost three-fold better as compared to the intensely mixed batch process. This was mainly a consequence of efficient reaction–diffusion dynamics in the microchannel system, where the developed flow pattern comprising of intense emulsification provided a large interfacial area for the reaction and simultaneous product extraction.