Salt effects on liquid-liquid equilibria in the ternary water/n-butanol/HMF system and solvent effects on HMF separation from water

Abstract

Experimental liquid-liquid equilibrium data of the ternary system composed of water, n-butanol and 5-hydroxymethylfurfural (HMF) as well as of quaternary systems containing water, n-butanol, HMF and salts are presented at 298.15 K and 1 bar. Salt effects of KCl, Na2SO4, Al2(SO4)3, NH4NO3, CH3COONa, C2H5COONa and C3H7COONa were studied. The quaternary system water/n-butanol/HMF/Na2SO4 was also investigated at 303.15 K due to the maximum Na2SO4 solubility in water near this temperature. HMF distribution ratios (Dw(HMF)) and HMF separation factors (αw(HMF,water)) were the parameters used to evaluate the salting-out effects on HMF and the extraction selectivity. The association behaviour of HMF in binary water/HMF and ternary water/HMF/LiCl mixtures was studied by means of DLS. The influence of different extractive solvents on the HMF distribution behaviour and on the HMF extraction selectivity was evaluated using corresponding LLE data from literature.