Alcohol production: downstream processes

The separation of bioethanol and biobutanol from dilute fermentation broth is an energy-intensive unit in the bioliquid fuel production chain. To well-address the technical barriers and improve the separation efficiency, in recent years, plenty of research has been carried out not only focusing on the improvement of the conventional distillation processes but also aiming to establish and applying the alternative nondistillation techniques for high-purity bioalcohol production. In this Chapter, the current advances in the distillation and nondistillation techniques for bioethanol and biobutanol separation are summarized. Principles, breakthroughs, and technical trends of the separation processes are discussed. We also make a perspective on the emerging field of integrated techniques and conclude by discussing the future direction toward the predictive understanding of bioalcohol separation.