Energy-efficient recovery process of 2,3-butanediol using 2-heptanol extraction

Abstract The high boiling-point of 2,3-butanediol requires high-pressure steam for its recovery from fermentation broth when distillation is directly implemented, as it vaporizes large amounts of water; such a process is expensive and not ecofriendly. Herein, 2-heptanol is proposed as an efficient extraction solvent, and the development of a combined extraction/ distillation process for energy-efficient recovery of 2,3-butanediol is presented. Information regarding the thermodynamic equilibrium model for process simulation was obtained from molecular simulation, and partially verified by experimental measurements. The feasibility of heat recovery was examined using pinch technology. The proposed process consumes more than a third less energy than the current extraction/distillation processes, resulting in a third lower total annualized costs. Because 98 % of feedstock water was removed by extraction with a low solvent/feed ratio, the energy demand of the distillation process was significantly lowered due to the use of 2-heptanol.