Advances and challenges in bio-based 2,3-BD downstream purification: A comprehensive review

Bio-based 2,3-butanediol (2,3-BD) is gaining prominence as an alternative to costly petroleum production. It finds diverse applications in chemicals, food, cosmetics, and more, notably as a polybutadiene rubber component. Recent advancements in 2,3-BD purification and increased concentration in fermentation solutions (exceeding 150 g/L) resulted from identifying 2,3-BD-producing bacteria and understanding productivity factors. Nevertheless, challenges arise from its high boiling point, hydrophilicity, complex fermentation broth composition, and costly separation from the broth (accounting for 50–70 % of production costs). The development of a cost-effective and effective separation method for 2,3-BD is essential. Recent developments in separation techniques, such as solvent extraction, pervaporation, and others, have been comprehensively reviewed for their in-situ and ex-situ applications. A techno-economic evaluation of these innovative approaches demonstrates significant reductions in energy consumption (up to 54.8 %) and downstream separation expenses (ranging from 25.8 % to 61.2 %), highlighting their potential to enhance the industrial production of 2,3-BD.