Research Contents

Area of research deals mainly with the idea of a “decarbonization toward the realization of sustainable energy, industry, and society,” covering some keywords of decarbonized system, energy system design, carbon-free secondary energy, process integration and optimization, advanced energy conversion, thermal engineering, heat transfer, energy saving, waste-to-energy, renewable energy, hydrogen, energy storage (including battery and electric vehicle), and energy utilization. Below are several research contents performed currently in our laboratory. However, as the research is developing, newer research topics are added and conducted at any time.

 当研究室は持続可能な社会の実現を目指し、高効率かつクリーンなエネルギーシステムの構築を行う。各個のエネルギー変換プロセス・要素技術内のミクロからマクロスケールまでの現象を解析・モデル化し、それらを統合化・体系化する。また、化学エネルギーだけではなく、電力の高度生産・利用および化学エネルギーとの相互変換・利用についても検討を行う。 以下に、当研究室で現在行われている研究内容をいくつか紹介する。しかし、研究の発展に伴い、随時新しい研究テーマが追加され、実施されています。

Integrated Energy Systems for Multigeneration

Design, integration, and optimization of industrial and energy systems are conducted, including the introduction of clean and carbon-free energy sources (both primary and secondary), creation of systems and networks for their interconversion and utilization, and building new integrated or retrofitting systems. Integration and optimization of the overall system, as well as individual energy conversion processes, are performed. To model a feasible and dynamic system, various big data are utilized to establish optimal operating parameters, e.g., by big data-based machine learning and genetic algorithm, and to evaluate overall system operation. In addition to technical evaluation, this study will also conduct economic feasibility studies.


Keywords: multigeneration, process design, computational fluid dynamics, renewable energy, exergy recovery, energy efficiency, process integration, power generation, big data, data-driven, genetic algorithm, prediction, optimization

Mutual co-utilization of secondary energy sources
Integrated renewable-based multi-generation systems

Clean Hydrogen Production, Storage, and Utilization

Highly efficient hydrogen production, storage, and utilization systems are modeled and analyzed based on the concepts of exergy recovery and process integration. Hydrogen production employs chemical looping, which is able to separate CO2 and produce highly pure hydrogen. The chemical looping system under development consists of three reactors (reduction, oxidation, and combustion), and oxygen carriers are circulated between the reactors. In this study, both experiments and simulations are conducted to establish the process, increase efficiency, and solve problems for demonstration. For hydrogen storage, to achieve higher efficiency and performance in metal hydride hydrogen storage, a triply-periodic minimum surface (TPMS) structure is introduced as the basic structure, and its optimal structure, operating conditions, and system integration are verified. The TPMS structure is lightweight, very strong, and has a large surface area per volume. Therefore, it is expected that the performance of conventional metal hydride hydrogen storage can be greatly improved by efficiently utilizing the properties of the TPMS structure. Numerical models, calculations, and experiments are conducted to verify not only the development of elemental technology but also the possibility of application. Regarding hydrogen utilization, advanced combustion simulations (turbulence models and detailed chemical reactions) are developed to model and analyze complex and difficult-to-visualize hydrogen and ammonia combustion flames to achieve a more accurate prediction of hydrogen combustion phenomena. It also aims to establish a digital twin technology in hydrogen combustion by using accumulated data and machine learning techniques to achieve short-time and low-resource calculations.


Keywords: chemical looping, low-rank fuel, biomass, hydrogen storage, triply periodic minimal surface, metal hydride, combustion, large eddy simulation, hydrogenation, dehydrogenation, carbon capture and storage (CCS), liquid organic hydrogen carrier, ammonia

Chemical looping CO2-free hydrogen production (left) and triply periodic minimal surface structure for metal hydride-based hydrogen storage
Hydrogen combustion simulation and prediction

Energy Management System and Energy Storage

This topic deals with the development of future energy systems, covering multi-disciplinary fields of mechanical, chemical, and electrical engineering. There are several main topics in this section: the development of environmentally-friendly iron-based redox flow battery, optimization of nanoscale structure for electrochemical energy storage systems (electrolyzer, fuel cell, etc.), the utilization of electric vehicle (EV) and battery in energy systems, and adoption of hydrogen as energy storage in the electrical grid system. In the case of battery and EV utilization, both of them have the potential to perform ancillary services to the grid, such as frequency regulation and energy storage. Furthermore, the analysis of hydrogen storage in a massive electrical grid system, instead of pumped-hydro and battery, is developed and analyzed. In the future energy system, both hydrogen and battery (including EVs) have great potential as they perform important roles as energy storage and carriers, including in industrial systems.


Keywords: redox flow battery, energy storage, microstructure, community energy management systems (CEMS), electric vehicle (EV), battery, charging station, ancillary services, queueing, renewable energy

Advanced Utilization of Low-Rank Energy Sources and Wastes for Efficient Energy Production

Keywords: waste-to-energy, industrial wastes, agricultural wastes, energy conversion, hydrothermal, process design, secondary energy source, recycling

Hybrid renewable and waste-to-synthetic natural gas

Advancement in Elemental Technologies

Keywords: heat transfer enhancement, drying, exergy recovery, heat coupling, fluid dynamics

Main Measurement Facilities in Lab

Thermogravimetry and differential thermal analysis (TG-DTA)Rigaku TG-DTA EV02
Gas chromatography (GC) TCD and FID (with methanizer)Shimadzu GC-2014
Gas chromatograph (GC) TCDGLS GC-3200
Fourier transform infrared spectroscopy (FTIR) with ATRShimadzu IRXross + QATR 10
Raman System StellarNet (532 nm, 200 – 5250 cm-1) with adjustable CW laser 0 – 100 mW
Mass spectrometry (MS)Ulvac Qulee with YTP-H BGM2-202
X-ray diffraction (XRD)Rigaku MiniFlex 600
Battery test systemScribner 580 (eight channels)
CellTest Multichannel PotentiostatSolartron CellTest 1470E
Potentiostat/GalvanostatMetrohm Dropsens ST400
High-speed cameraChronos 2.1-HD
UV-VisShimadzu UV-1900i
LCR meterLCR-6200
Gas analyzerTesto 350 (with six gas sensors: CO, CO2, O2, NO, NO2, SOx)
Combustion test chamber
Photo reactor system
Power AnalyzerHioki 3920
pH meterEutech PCWP300
and many others …