(471b) Fractionation of Lignocellulosic Materials for Biorefinery: Lignins and Hemicelluloses

Lignocellulosic materials represent an abundant carbon-neutral renewable resource for the production of bioenergy and biomaterials. A concept for converting renewable lignocellulosic materials to valuable biofuels, chemicals, and biomaterials generally has been referred to as biorefinery. Lignin, one of the three main constituents of lignocelluloses, is undervalued as a by-product of the biorefinery. Hemicelluloses are heterogeneous polymers of pentoses (xylose and arabinose), hexoses (mannose, glucose and galactose), and sugar acids, which are usually degraded during the biorefinery. The development of value-added products from lignin and hemicelluloses will greatly improve the economics of these processes. However, value added applications from lignins and hemicelluloses need a proper investigation of their inherent properties, which significantly affect their applications. In this paper, the recent research in our group on fractionation and structural characterization of lignin and hemicelluloses from lignocellulosic materials for biorefinery has been reviewed. The structural features of the lignin and hemicelluloses obtained were elucidated by various destructive and non-destructive techniques. It was believed that the in-depth investigation of the structure features of lignin and hemicelluloses will be beneficial to understand the potential of these materials for future value added applications. Moreover, novel functional biopolymers and biomaterials, such as ionic hydrogels and nanocomposite films, from hemicelluloses were developed. The results showed that the ionic hydrogels had high water adsorption capacity and showed rapid and multiple responses to pH, ions, and organic solvents, which may allow their use in several areas such as adsorption, separation, and drug release systems. The effective method developed makes it possible to produce hemicellulose-based biomaterials with improved mechanical properties.