Phase Interface Science for Energy Efficient Society/CRDS-FY2010-SP-05
Executive Summary

This report proposes that the government should strategically promote the basic research on "Phase Interface Science for Energy Efficient Society," which must be a key for highly efficient energy utilization.

In order to overcome global issues such as global warming and resource exhaustion and establish a sustainable well-being society, it is indispensable to attain ultimate energy efficiency as well as to develop novel energy technologies by keeping a wide range of perspective from the supply side to the demand side. Unfortunately, there is no confirmed single energy resource that can substitute enormous fossil energy consumption economically and quantitatively, even if we envision the year of 2030. Therefore, it is mandatory to satisfy the following two requirements for energy technologies to be developed regardless of renewables or non-renewables, i.e., a substantial volume which meets huge global energy consumption, and a sufficiently low cost to be competitive against conventional energy supplies. Considering the energy issues broadly from viewpoints of revolutionary and quantitative contributions, it becomes clear that we should promote research for basic science, design, manufacturing and control technologies for phase interface phenomena.

In any energy device or system, interfaces or boundaries exist between different materials and different phases such as solid, liquid and gas, where mechanical, chemical and/or electromagnetic phenomena take place. All losses, which hider the achievement of theoretically best possible performance of energy technologies, originate from irreversibility in the energy conversion, transport and storage processes, and they take place mostly at phase interfaces. It is thus crucial to drastically reduce these losses for much better energy saving and energy efficiency and for new energy introduction. In other words, the performances and efficiencies of real energy systems can be pushed toward the best limiting values by exploring the entire fundamental processes of energy transport and conversion and also by enabling designs that minimize the irreversible losses. For example, Fig. 1 shows phase interface phenomena found in an integrated gasification fuel cell system (IGFC), which is considered as an ultimate power generation system in the future. Analyses and advanced design methodologies of various phase interfaces, e.g., fuel cell electrodes, gas turbine blades, gasification and exhaust gas catalysis surfaces, lean burn combustion flame interfaces, gas separation membranes, will as a whole lead to ever more efficient energy utilization and global warming prevention. As in this example, deepening the basic phase interface science and developing control/ optimization technologies will enable drastic reduction of energy losses and creation of unprecedented functional processes. This will eventually strengthen the nation's lasting competitiveness in the energy related technologies through drastic improvement in the efficiencies and costs of conventional as well as new technologies.

In order to achieve these goals, analyses for understanding phase interface processes and elementary steps as well as design sciences for optimizing and controlling the phase interfaces are required. Phase interface phenomena take place at multiple levels from nano, meso to macroscopic scales. In order to exploit breakthroughs in nano scale material research for designing macroscopic scale systems, it is required to handle comprehensively the phenomena of diverse scale ranges across tera orders. Development of measurement techniques and modeling and simulation tools, which can holistically analyze and design multi-scale systems, will make it possible to reflect fruitages from advanced basic research in real applications. In addition, collaboration and amalgamation of analytical and synthetical researchers is indispensable. A breakthrough can be achieved only when multidisciplinary scientists and researchers, e.g., material, chemical, mechanical, electrical, physical and mathematical researchers, are invited to gather together and collaborate under the shared mission objective for energy. In addition, it is very important that the basic research outcomes should eventually be integrated into mass production processes. In order to facilitate this knowledge transfer, it is recommended to feedback required functions and also environmental constraints to early stages of basic research. It would help if institutional measures are taken to form researchers' networks between academia and industry, and social and economical needs are taken into account when thematic prioritization is made in the basic research.

Phase interface phenomena are the processes that energy carriers are transferred and converted between different materials and phases, and in fact they are found in every human activity. Thus, the outcomes of phase interface science research will produce extensive spill-over effects being applied not only to energy related technologies but also to a much wider range of applications, so their impacts on the industry and the society will be enormous.