Today, at the threshold of the 21st century, rising apprehensions about the instability of oil prices, energy security, and adverse effects of fossil fuels on the environment, have made it imperative to search for alternative energy resources that are clean and sustainable. Among various biofuels, bioethanol is very promising. Bioethanol obtained from the fermentation of biomass is dilute and needs to undergo recovery and dehydration before its use as a fuel. This separation step is one of the energy-intensive steps in bioethanol production, which continues to motivate continual advances in bioethanol separation design. Hence, this review paper focuses on the recent advancements in the development of bioethanol recovery and dehydration processes. It is organized in the form of an annotated bibliography, whereby 54 journal papers and book chapters from the year 2008 to 2016 are summarized based on a classification according to separation technology employed. In addition, quantitative performance indicators (namely, cost and energy required for separation) in the papers/book chapters reviewed are presented on a consistent basis (per unit of bioethanol produced). All these will be useful to researchers and practitioners for technology selection and/or further advances in bioethanol separation.

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Isobaric vapor−liquid equilibrium for the binary system of tert-butyl alcohol (TBA) + glycerol were obtained at local atmospheric pressure of 95.9 kPa and subatmospheric pressures of 66.6 and 79.9 kPa over the entire composition range using a modified Othmer-type ebulliometer. Wilson and NRTL models were used for correlating the experimental data. The results suggest that the NRTL model represented the experimental data better with lower RMSD and AAD values. Furthermore, at local atmospheric pressure of 95.9 kPa, the densities and refractive indices for the three binary systems TBA + glycerol, TBA + water, and water + glycerol involved in the dehydration of TBA by extractive distillation were measured over the entire composition range from 303.15 to 333.15 K. The volumetric properties in terms of excess molar volume, partial molar volume, and isobaric thermal expansivities as well as molar refractivity were evaluated and analyzed for the three different binary systems. A Redlich−Kister polynomial was used to the fit the excess molar volume and deviations in molar refractivity. Different empirical mixing relations were also investigated for predicting the refractive indices of the three binary mixtures and are reported in terms of their average percentage deviation.

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