Fractionation of birch wood biomass into valuable chemicals by the extraction and catalytic processes.

For the first time, the process of extraction fractionation of "hemicelluloses-free" birch wood in an ethanol medium into cellulose product and ethanol lignin is studied and optimized. The composition and structure of cellulose product and ethanol lignin obtained by extraction fractionation of "hemicellulose-free" birch wood and other products of their subsequent transformations are characterized by methods of infra-red spectroscopy, nuclear magnetic resonance, X-ray diffractometry, scanning electron microscopy, BET surface area analysis, high-performance liquid chromatography, gel permeation chromatography, gas chromatography, and chemical and elemental analysis. The possibility of producing enterosorbents from birch ethanol lignin that are more effective than the commercial enterosorbents "Polyphepan" based on hydrolyzed lignin is established. A new approach to the biorefinery of birch wood into xylose, levulinic acid and enterosorbents is proposed based on the integration of an optimized process of extraction fractionation of "hemicellulose-free" birch wood in ethanol medium, alkaline isolation of xylan and its hydrolysis to xylose, cellulose product conversion into levulinic acid and ethanol lignin processing to enterosorbents. [ABSTRACT FROM AUTHOR]