Transport of monosaccharides contained in an ionic liquid/aqueous mixture via a supported liquid membrane

Lignocellulosic materials are renewable biomass that can be utilized in the development of biofuels such as ethanol. Hydrolysis of hemicellulose and cellulose, contained in pretreated biomass, produces monosaccharides that are fermented to produce ethanol. Since lignocellulosic materials possess resistance to hydrolysis, the methods currently involved are not cost-effective for large scale ethanol production. Ionic liquid pretreatment of biomass is a relatively new approach that has gained popularity due to its capability of decrystallizing cellulose effectively. The cellulose contained within an ionic liquid is more readily available for hydrolysis by acids or bases to their constituent monosaccharides. These monosaccharides need to be separated from the other constituents (lignin and other impurities), which may inhibit the downstream fermentation process. This technique can be implemented to produce high quality feed solutions for fermentation thus increasing the yield of ethanol produced. The work conducted aims to achieve this separation by transporting the monosaccharides (glucose and xylose) contained in an ionic liquid (1-ethyl-3-methylimidazolium acetate)/aqueous mixture via a supported liquid membrane impregnated with phenylboronic acid and quaternary amine (Aliquat 336) extractants and the diluent, 2-nitrophenyl octyl ether. The monosaccharides are transported to an aqueous neutral receiving phase. Comparisons are made to similar trials where the departure phase is an aqueous pH 11 buffer