Yoshito Oshima / Professor / Division of Environmental Sciences
Department of Environment Systems / Environmental Risk Assessment Laboratories / Fundamentals and Application of Supercritical Fluid Technology

Career Summary
1986: Graduated, Faculty of Engineering, The University of Tokyo
1991: Doctor of Engineering from The University of Tokyo
1991: Research Associate, The University of Tokyo
1995: Lecturer, The University of Tokyo
2000: Associate Professor, The University of Tokyo
2003: Professor, The University of Tokyo
Educational Activities
Graduate School: Environmental Technology Development, Safety for Environment and its Systems
Research Activities
Development of techniques to reduce environmental burden through the use of supercritical fluids (1992-present):
"Supercritical fluid" refers to a fluid in which the critical points of temperature and pressure for the material are being exceeded. Dramatic physical changes are possible depending on the operating conditions of the material.

In particular, the ionic content and dielectric constant of supercritical water varies extensively depending on temperature and/or pressure. Consequently, it becomes possible to select a reaction based on one's objective ranging from an ionic atmosphere suitable for inorganic reactions, to one implementing the dissolution of organics, which is equivalent to a non-polar solvent.

Taking advantage of these properties, it is expected that this new, inexpensive, environmentally-friendly reaction media will replace conventional organic solvents.
For example, a waste disposal process which utilizes supercritical water will provide techniques for very efficient high-speed dissolution and detoxification of industrial and experimental waste fluids. This new countermeasure technique also brings more social attention to the serious environmental issues of waste disposal.

Our laboratory has many research goals, covering a broad range of topics: Destruction harmful waste products using oxidation reactions of supercritical water, organic synthesis using solid catalysts, and synthesis of inorganic materials such as nanoparticles and polymers.

In regard to all of these fields, by designing, analyzing, and controlling reactions based on the study of chemical reaction rate and reaction engineering, we are advancing research over an extensive range, from fundamental research related to chemical reactions of supercritical fluids to the development of new engineering application technologies.

1) Rumiko Hayashi, Masato Onishi, Masakazu. Sugiyama, Seiihiro Koda and Yoshito Oshima, "Kinetic Analysis on Alcohol Concentration and Mixture Effect in Supercritical Water Oxidation of Methanol and Ethanol by Elementary Reaction Model", J. Supercritical Fluids, 40(1), 74-83 (2006)
2) Kengo Tomita and Yoshito Oshima, "Stability of Manganese Oxide in Catalytic Supercritical Water Oxidation of Phenol", Industrial & Engineering Chemistry Research, 43, 7740-7743 (2004).
3) Junichi Otsu and Yoshito Oshima, "New Approaches to the Preparation of Metal or Metal Oxide Particles on the Surface of Porous Materials Using Supercritical Water: Development of Supercritical Water Impregnation Method", Journal of Supercritical Fluids, 33(1), 61-67 (2005).
Other Activities
The Society of Chemical Engineers, Japan
The Chemical Society of Japan
The Japan Petroleum Institute
Japan Society of Safety Engineering
Future Plan
Needless to say, securing environmental safety in experimental research is a prerequisite for the purposes of driving science and technology research in support of the foundation of a technological powerhouse.

Subsequent to the development of universities and research institutes into independent administrative entities, outfitting of safety-health control systems is spreading in correspondence with laws and regulations.

Unfortunately, however, the present condition is that this is not enough to fully realize the embodiment of safe environmental philosophy in actual research environments.

In order to resolve this dissociation between the ideal and reality and to implement environmental safety philosophy, it is important to have a voluntary attitude towards risk-control which goes beyond observing rules and regulations.

Therefore, we plan to develop and spread logical and versatile risk visualization tools to support quantitative evaluation by researchers themselves.

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