13-30: Separation of sugars from biomass hydrolysate using plasticized liquid membranes

Pretreatment and saccharification of lignocellulosic biomass results hydrolysate that is rich in monomeric sugars such as glucose and xylose. However, hydrolysates often contains potential contaminants, such as phenolics, which can have deleterious effects on downstream process steps such as fermentation. Less than optimal utilization of biomass sugars due to these contaminants may lead to unfavorable process economics.

Plasticized liquid membranes (PLM) can be used to selectively remove sugars from the hydrolysate, thereby eliminating the problems associated with contaminants and producing a desirable sugar feedstock. PLMs are lipophilic in nature and are robust in a variety of aqueous environments. In this research, PLMs containing carrying agents such as quaternary ammonium salts and/or complexing agents such as aryl boronic acids are tested with model glucose/xylose solutions, the sugars most commonly found in biomass hydrolysate. Composition of the membranes was varied by changing concentrations of the carrying agents and plasticizing agents. The effects of the membrane porosity, thickness, and composition on sugar flux and membrane stability are reported.