Partition behavior of hydrophilic diols in an ethanol/ammonium sulfate salting-out extraction system

It is important to investigate the partition behavior of hydrophilic alcohols at different process parameters in order to have a deep understanding of the salting-out extraction technique and to design suitable downstream processes. First, phase diagram data of ethanol/ammonium sulfate at 293.15K were obtained, and the reliability of binodal curve and tie line data were proved by Merchuk, Othmer-Tobias, and Bancroft equations, respectively. Then, the partition behavior of five short-chain diols was studied. For different tie lines, the partition coefficient changed linearly with an increase in tie line length. The concentration of diols also had a significant effect on the partition behavior due to the similarity between diols and ethanol. Further, the effect of temperature was increased as the hydrophobicity of the diols increased, and the partition behavior of diols was correlated with their hydrophobicity, implying that the solutes with higher hydrophobicity could be extracted more effectively. These findings are useful for designing an economic and efficient salting-out extraction process for diverse products.