Recovery of 1,4-butanediol from aqueous solutions through aqueous two-phase systems with K2CO3

Abstract

1,4-butanediol (BDO) can be produced by the biotechnological route; however, the process of separating BDO from fermentation broths is energy-intensive due to its high boiling point and complete miscibility with water, which motivates to propose separation routes that involve energy savings. Therefore, an aqueous two-phase system was proposed for the recovery of BDO from aqueous solutions using K2CO3 as a phase-forming agent, without the need for additional solvent. The liquid-liquid equilibrium of the system K2CO3 + BDO + H2O was determined at 25 °C and the ENRTL-RK thermodynamic model was used to correlate the experimental data and perform the process simulation in Aspen Plus. Applying this technique, it was possible to concentrate a BDO solution from 12.5% w/w to 84.58% w/w in a liquid-liquid extraction stage with a recovery of 99.59%. Therefore, K2CO3 is a dehydrating agent that could be used for the recovery of BDO obtained by fermentation.