Utilization of Sub- and Supercritical Water for Nano-Catalyst Synthesis and Waste and Biomass Processing

• Published in: Waste and biomass valorization Vol. 13; no. 1; pp. 51 - 66
• Main Authors: Yoko, Akira, Seong, Gimyeong, Tomai, Takaaki, Adschiri, Tadafumi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.01.2022; Springer Nature B.V
• Subjects: Biomass; Catalysts; Cellulose; Chemical synthesis; Engineering; Environment; Environmental Engineering/Biotechnology; Fractionation; Hydrothermal reactions; Hydrothermal treatment; Industrial Pollution Prevention; Metal oxides; Nanoparticles; Original Paper; Oxidation; Reforming; Renewable and Green Energy; Waste Management/Waste Technology; Waste materials; Lignin; Cubic CeO; nanocatalysts; Supercritical hydrothermal synthesis; Heavy oil; Cellulose
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-021-01483-1

Two techniques using subcritical and supercritical water are introduced herein: supercritical hydrothermal synthesis of metal oxide nanoparticles and hydrothermal processing of waste and biomass. Recent progress of supercritical hydrothermal synthesis method is reviewed particularly for oxidation catalysts. Then hydrothermal treatment methods for biomass and waste are summarized from the viewpoint of phase behavior, homogeneous reaction, and reaction with catalysts. Fractionation of valuable materials through reforming of biomass and waste using the characteristic properties of the hydrothermal reaction field is emphasized. Cellulose and lignin, the major components of woody materials, and heavy oil as a representative waste material have been studied intensively for treatment under hydrothermal conditions. Process design aspects are discussed to provide a future scope of related technologies. Graphic abstract