Process for Isolating C5 Sugars from Biomass Hydrolyzate

Technology University of Louisville researchers have developed a novel process for isolating C5 sugars from biomass hydrolyzate that yields xylose and minor quantities of arabinose as solids both of which are widely used in food medicinal and industrial applications. This process part of C5-based biorefinery initiative is a low-cost non-thermal process that eliminates the need for traditional high-energy consuming steps such as evaporation concentration or ion exchange. This C5-based biorefinery uses "captive" high hemicellulose containing lignocellulosic feedstock as a starting material and coexists with cellulose-based biorefineries to produce high value products like bicyclopentane (BCP; a high energy density component of jet fuel) and facilitates the production of a C6-platform of products in addition to the C5-platform. The three-step xylose isolation process begins with phenylboronic acid (PBA) complexation of xylose to form furanose diester XDE which is cleanly extracted into organic phase. The second and key step of the process precipitates a liberated xylose as D-xylopyranose to afford the monosaccharide for use in subsequent synthetic transformations. The final step of the process recovers PBA from the polymer and regenerates the polymer-diol for subsequent runs of the isolation cycle allowing for the solvents and reagents to be recycled for multiple uses. This process effectively reduces the number of high energy consuming concentration and precipitation steps used by current methods. Further use of inexpensive reagents and mild conditions make this technology economically feasible for biofuel production and the selective hydrolysis process allows for isolation of arabinose and xylose as mixed or high purity sugars. Applications: This technology has potential applications in two primary market areas: biofuel and renewable energy.