초록
<P><B>Abstract</B></P> <P>Salting-out extraction is an efficient technique for the separation of bio-based chemicals from fermentation broths. So far, salting-out extraction of 2,3-butanediol has mainly focused on systems composed of organic solvents and salts, while less attention has been given to the green solvent ― ionic liquids. In this research, imidazolium ionic liquids were used to examine the recovery of 2,3-butanediol from fermentation broths. The influences of the temperature and concentration of 2,3-butanediol on phase formation were determined using two systems of 1-butyl-3-methylimidazolium chloride ([C<SUB>4</SUB>mim][Cl])-K<SUB>2</SUB>HPO<SUB>4</SUB> and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([C<SUB>2</SUB>mim][CF<SUB>3</SUB>SO<SUB>3</SUB>])-K<SUB>2</SUB>HPO<SUB>4</SUB>. The partition behaviors of 2,3-butandiol and ionic liquids, and the selectivity of 2,3-butanediol over glucose and organic acids were investigated and compared at different concentrations of ionic liquids and K<SUB>2</SUB>HPO<SUB>4</SUB>. Most of 2,3-butanediol and ionic liquids were distributed to the top phase, whereas different trends of partition coefficient variation were observed. Under the condition of 25% [C<SUB>2</SUB>mim][CF<SUB>3</SUB>SO<SUB>3</SUB>]-30% K<SUB>2</SUB>HPO<SUB>4</SUB> (<I>w/w</I>), the recovery of 2,3-butanediol and [C<SUB>2</SUB>mim][CF<SUB>3</SUB>SO<SUB>3</SUB>] was 95.7% and 99.5%, respectively, and selectivity for glucose, succinic acid and lactic acid was 2.59, 115 and 20.8, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Partition of 2, 3-butandiol in ionic liquid-based aqueous two-phase systems. </LI> <LI> [C<SUB>2</SUB>mim][CF<SUB>3</SUB>SO<SUB>3</SUB>]- and [C<SUB>4</SUB>mim][Cl]-K<SUB>2</SUB>HPO<SUB>4</SUB> systems were studied. </LI> <LI> Different trends of partition coefficient variation were observed. </LI> <LI> Selectivity for glucose, succinic acid and lactic acid was investigated. </LI> <LI> 95.7% 2,3-Butanediol and 99.5% [C<SUB>2</SUB>mim][CF<SUB>3</SUB>SO<SUB>3</SUB>] were distributed to the top phase. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>