Salt induced phase separation extraction of 2,3-Butanediol from aqueous solutions: Recovery and recycling of potassium triphosphate

A novel salt (potassium triphosphate, K5P3O10) induced phase separation to extraction of 2,3-butanediol (BDO) from aqueous solution and its recycling were studied. This paper investigated factors influencing salt induced phase separation (SIPS) extraction efficiency, including salt type and concentration, solute content, equilibrium time and temperature, and solution pH. With BDO concentration 15% (w/w) and K5P3O10 concentration 600 g center dot kg- 1, this system can achieve complete phase equilibrium within 8 min, the extraction efficiency, distribution coefficient and selectivity for BDO were 99.5 +/- 0.5%, 2406.1 +/- 174.5, 5940.2 +/- 260.9 respectively. Moreover, the process only has two steps (shaking and standing), the extraction time was about 15 min, which was much shorter than that in previous studies reported. In addition, there was no need for solvent in extraction process, after dehydration, the purity of the product is 91.0%. Reused six times, the recovery of salt and extraction ef-ficiency of BDO almost did not change. Finally, the binodal curves and solid-liquid equilibria line of novel SIPS system were also determined at 298.15 K. As a green technology in chemical industry, this method has the advantages of high extraction efficiency and provides a potential for separation and refining of BDO for its convenience, economy, and easy to scale-up.