Development of Total Utilization Method of Woody Waste by Green Technology

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Woody biomass is renewable resources that can be converted into useful materials and energy. The amount of carbon contained in woody waste annually occurred and emitted into environment in Japan is about 30-40% of carbon consumed to produce a variety of petrochemicals from oil. The development of industrial technique for converting a raw material into useful materials and products completely without generating pollutants such as waste gas, wastewater, and solid waste materials is expected significantly for the global environmental protection on the base of zero emission. The holocellulose, i.e. cellulose and hemicellulose, in woody waste such as wood chips, baggase, bamboo, bark, and sweet sorghum are natural organic resources utilizable for the production of sugars. However, the holocellulose are with difficulty converted into sugars by direct biological means in a native state because a lignin network covers the holocellulose layers in the cell walls. Various different physical, chem … More ical and biological pretreat-ments have been attempted to degrade the lignin in the biomass or to remove it from the holocellulose surface. In recent years, a steam explosion that consists of steam hydrolysis with a high temperature and pressure and a mechanical treatment of the hydrolyzed product with a sudden reduction of the pressure, has been attractive as an effective pretreatment for depolymelizing the lignin in woody biomass. In this work, the treatment and conversion system of plant biomass waste into useful materials was developed for zero emissions by using steam explosion and various conversion methods. This system was a significant conversion approach without generating pollutants, i.e. waste gas, wastewater, and solid waste materials. The conversion of woody wastes into useful materials was studied for the effective utilization of its components such as holocellulose, water-soluble material, methanol-soluble lignin, and Klason lignin. The holocellulose, water-soluble material, methanol-soluble lignin, and Klason lignin were converted into useful materials, i.e. lactic acid or antibacterial violet pigment and methane gas, monosaccharides and oligosaccharides, epoxy resin without an estrogenic activity, and activated carbon, respectively. The amounts of useful materials and products produced from each component were estimated, and the reduction of pollutants generated in their production process and waste treatment, and the detoxification of the lignin resin were confirmed. Less