2,3-Butanediol (2,3-BDO) is a key bio-based platform chemical with wide-ranging applications in fuels, synthetic rubber, pharmaceuticals, and polymer industries. The sustainable production of 2,3-BDO via microbial fermentation of renewable biomass has gained significant attention as an alternative to fossil-based routes. However, the efficient recovery of 2,3-BDO from fermentation broth remains a critical challenge, primarily due to its high boiling point, strong hydrophilicity, and relatively low concentration in aqueous systems. These characteristics render conventional separation processes, particularly distillation, highly energy-intensive and economically unfavorable. This review systematically summarizes the current advances in downstream processing technologies for 2,3-BDO recovery, including distillation, liquid–liquid extraction, gas stripping, adsorption, membrane-based separation, and the emerging salting-out extraction method. The fundamental principles, advantages, limitations, and recent developments of each technique are critically analyzed. In particular, salting-out extraction is highlighted as an effective strategy for enhancing the partitioning of hydrophilic compounds and reducing energy consumption. Furthermore, hybrid separation processes that integrate multiple techniques, as well as in situ product recovery (ISPR) approaches, are discussed for their potential to improve process efficiency and alleviate product inhibition during fermentation. Finally, future perspectives are proposed, focusing on the development of green solvents, advanced membrane materials, and intensified hybrid systems. These innovations are expected to enable more efficient, cost-effective, and sustainable recovery of 2,3-BDO, thereby facilitating its large-scale industrial application within emerging biorefinery frameworks.
Cai et al. (Tue,) studied this question.