Esterification of fusel oil using reactive distillation – Part I: Reaction kinetics

Fusel oil is a mixture of C2–C5 alcohols such as ethanol, n-propanol, iso-butanol and iso-amyl alcohol. It is expected that reactive distillation (RD), which is a proven intensification strategy for esterification of individual alcohols can also be a promising option for simultaneous esterification of all the alcohols in fusel oil. To evaluate its feasibility and design a unit on large scale, kinetic and phase equilibrium models are necessary. In this work, we experimentally investigate reaction kinetics for all the esterification and trans-esterification reactions of the different constituents of fusel oil with acetic acid. The reactions are performed in the presence of cation exchange resin, Amberlyst-15, in a batch reactor over a wide range of parameters such as temperature, mole ratio and catalyst loading. A unified Langmuir–Hinshelwood–Hougen–Watson (LHHW) model is proposed for the reacting system consisting of all the alcohols and the experimental data is used to estimate the model parameters. The predictions are in line with the experimental data for individual alcohols as well as their mixtures. A feasible process based on reactive distillation is simulated in ASPEN PLUS using the kinetics developed in this work.

• We present a process for value addition to fusel oil by esterification using RD. • A unified LHHW kinetic model is presented for the different reactions involved. • Applicability of the developed kinetic model to a feasible RD process is shown.