Dr. Takeshi Sako is professor emeritus at Shizuoka University in Japan. He received his PhD from Tokyo Metropolitan University. He worked on chemical engineering at National Institute of Advanced Industrial Science and Technology for 22 years. He became professor at Department of Materials Science and Technology at Shizuoka University in 2000. He was deans of Faculty of Engineering and Graduate School of Integrated Science and Technology from 2013 to 2017. He has worked on the supercritical/subcritical fluid technology for more than 30 years. In particular, he is interested in the application of this technology to the field of energy and earth environment. He has studied the production of many kinds of bio-fuels from waste/unused materials, the recycling of waste plastics and the decomposition of toxic substances using supercritical /subcritical water, supercritical methanol and supercritical carbon dioxide. He received the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology on “Study of earth environmental protection technology using supercritical/subcritical fluids” in 2011.