Ion exchange separation for recovery of monosaccharides, organic acids and phenolic compounds from hydrolysates of lignocellulosic biomass

This paper describes two effective ion exchange chromatography processes to separate and recover monosaccharides, organic acids and phenolic compounds from two kinds of hydrothermal liquefaction (HTL) hydrolysates derived under different temperatures. Anion exchange resin Amberlyst A21 (OH−) and cation exchange resin Amberlite IR-120 (Na+) were selected to separate synthetic solution and real hydrolystes by column chromatography. The results showed that glucose and acetic acid could be successfully separated by anion resin with purities of 87% and 98%, respectively. Acetic acid and phenol could be recovered by cation resin with purities up to 97% and 81%. In separation processes of real HTL hydrolysates, monosaccharides and organic acids in hydrolysate derived from low-temperature HTL were separated by anion exchange resin with recoveries of about 80% and 90%, respectively. Phenolic compounds in high-temperature HTL hydrolysate were recovered by cation exchange resin with recovery of about 70%.