(302f) Daizo Kunii, the Chemical Engineer

I graduated from the University of Tokyo (UT) wherein I learned a lot from Prof. Daizo Kunii at the Kunii Laboratory. Every day at lunchtime, he used to fondly share his experiences with us. After graduating from the Aerospace Engineering Department, Young Daizo Kunii had the opportunity to work in the Chemical Engineering Department of UT, which was an entirely different field. He said he made every effort for his boss to recognize him and finally succeeded when he came up with a new scientific theory on radiation heat transfer with his strong background in mathematics. Simultaneously, he also summarized a design method for a furnace.

Nowadays, the importance of inter-, multi-, and trans- disciplinary research is recognized on every issue, but Prof. Kunii demonstrated it more than half a century ago. He had the opportunity to study the development of a new process for coal gasification and waste treatment. Moreover, he was attracted by fluidized bed technology. He recognized the importance of an engineering viewpoint, solution engineering, and needs-oriented research during this period. He always told us that organizing different researchers is similar to conducting an orchestra; the chemical engineer being the conductor. Interestingly, one of the research topics of Kunii laboratory is the methodology of invention wherein a new idea is created from other ideas with processes similar to mathematics (multiplication, transfer matrix, reverse matrix, etc.).

Prof. Daizo Kunii was a chemical engineer. I owe a lot to him for his teachings about the engineering sense and the method of invention, namely: mixing the unmixable and organizing. Hence, after graduating from UT, I focused on the fusion (multiplication) of different researches to create a new research field, similar to what Prof. Kunii did during his younger years; this was achieved by organizing different fields of researchers.

Particularly, materials can be categorized into three phases: gas, liquid, and solid. However, some physical chemistry textbooks said that there is one more phase, which is the supercritical phase. Thus, I tried to use the supercritical state for several reactions (organic, inorganic, coal, petroleum, biomass, wastes, etc.) and in material synthesis.

Supercritical water provides an excellent hydrothermal synthesis reaction atmosphere to control phase behavior, reaction kinetics, and equilibrium with minimal changes in temperature and pressure. Interestingly, in the supercritical state, water and organic matter form a homogeneous phase, thus, resulting in organic-inorganic hybridization. This new process of mixing the unmixable can lead to the development of new materials, which cannot be synthesized by any other methods, such as nanomaterials with extremely high catalytic activity, hybrid materials of ceramics and polymers, and fluidic ceramics. Our proposed supercritical hydrothermal synthesis process was commercialized not only in Japan but also in other countries. With this, I have a feeling that I can finally realize what I learned from Prof. Daizo Kunii, that is, chemical engineering.