Chapters authored
Liquefaction of Wood by Ionic Liquid Treatment
Part of the book: Ionic Liquids
Microscopic Investigations on Woody Biomass as Treated with Ionic Liquids
Woody biomass is one of the most promising renewable alternatives to fossil resources. However, some physical and chemical treatment is required to convert their chemical components into biofuels and valuable chemicals because of their low degradative properties. Recently, there has been considerable interest in ionic liquid treatment for biorefinery, and many fundamental studies on the reactivity of wood with ionic liquids have been performed from a chemical and morphological point of view. This chapter highlights the findings regarding morphological and topochemical features of wood cell walls in the degradation process as a result of ionic liquid treatment. Bright-field microscopy and scanning electron microscopy have revealed the swelling behavior of cell walls and the detailed ultrastructural features of wood tissues treated with ionic liquid. Polarized light microscopy and confocal Raman microscopy have clarified the changes in cellulose crystallinity and distribution of chemical compositions such as polysaccharides and lignin during ionic liquid treatment at the cellular level.
Part of the book: Microscopy and Analysis
Depolymerization of Native Lignin into Vanillin, Vanillic Acid, and Other Related Compounds via Alkaline Aerobic Oxidation: Reaction Mechanisms and Process Control Using Organic Cations
Vanillin is one of the platform chemicals in industry, which is used not only as a traditional fragrance but also as a raw material for medicines and polymer materials. Industrial vanillin production by alkaline aerobic oxidation of lignin is carried out with degradation of lignosulfonate at temperatures around 170°C under pressurized air in the presence of Cu2+ as a catalyst. However, this method has problems such as low vanillin yields and by production of sulfur-containing wastewater, and various studies have been conducted to solve them. Research on the mechanism of the vanillin formation reaction by aerobic oxidation of lignin and the search for a method to control this reaction has also been conducted. In this chapter, we review relevant studies from the above perspective, mainly those conducted by the authors’ research group.
Part of the book: From Biomass to Biobased Products