Hydrogen energy provides a wide range of benefits for the environment, and for energy security, because it can reduce CO₂ emissions, can be used for energy storage and transmission and has fuel flexibility. On the other hand, in terms of combatting climate change, it is important to reduce CO₂ throughout the entire supply chain, because there are cases when CO₂ is emitted such as when hydrogen is produced from fossil fuels. To widespread use of hydrogen energy and tackle climate change problems, Ministry of the Environment conducts Hydrogen Program. This paper describes what MOE aims to realize by using hydrogen energy, and MOE’s program of R&D, supply chain demonstration, and LCA guideline.

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Potential environmental and energy security benefits associated with the use of hydrogen and fuel cells are promising. However, most hydrogen and fuel cell technologies are still underdeveloped. In order to realize a “hydrogen society” where hydrogen is as a major source of energy, a long-term strategy in research and development is needed to make a significant reduction in the associated cost and energy loss. Towards this objective, the Ministry of Economy, Trade and Industry（METI）has implemented and supported a research and development project called “Development of technology for storage and transportation of innovative hydrogen energy” since FY 2013. In this project, elemental technologies needed to realize a “hydrogen society” by around 2030 have been developed. In this paper, an outline of the project and its related activities are introduced.

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Upon the assumption that hydrogen energy system contributes to the realization of the low carbon society, a key step toward the sustainable society, the prospects of possible hydrogen energy system in 2050 is briefly presented. By using the global and long-term intertemporal optimization energy model GRAPE under severe CO₂ emission constraints, hydrogen is shown to have the domestic demand of eight hundred Mtoe（ca. 3 trillion Nm³/year）in Japan. Hydrogen is expected to be produced mainly from overseas renewable energy, and transported and stored in the form of the energy carriers, namely liquid hydrogen, organic hydride and ammonia. Globally hydrogen is mostly consumed in the transportation sector, but it will specifically attain the Japanese market as the fuel for hydrogen-fired power generation.

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Objective. The author tried to explain the energy and environmental issue with a way which amateur could understand. While explaining the energy flow in Japan, the author tried to give a model how CO₂ emission could be reduced in the future. Importance of CO₂ free hydrogen and the evaluation with LCA method is to be discussed.

Results and Discussion. The Japanese population and energy demand are subjected to decrease 1% annually up to 2050. In order to access to the government road map of CO₂ reduction 3 kinds of fossil fuels（oil, LNG and coal）must be reduced annually 2%, 1%, and 1% respectively. At the same time CO₂ free energy source（renewable, atomic, and CO₂ free hydrogen energy）must be increased to keep the total energy demand at an appropriate level. Importance of CO₂ free hydrogen energy is pointed out. The new technologies which are now under development are shown, especially for the case of utilizing ammonia as a fuel. Finally, two examples to introduce CO₂ free ammonia from abroad are shown. Tentative LCA are also discussed there.

Conclusions. Tentative values of carbon foot print of ammonia fuels are shown, which are about 1/4 and 1/10 of the value of gasoline for natural gas based ammonia with EOR operation and renewable electricity based ammonia, respectively. Further work is expected to examine these values in the future.

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Japan has a national goal of reducing greenhouse gas emissions in 2030 to 26% below 2013 levels. Energy efficiency improvement and low carbon power generation technologies will provide the primary source of greenhouse gas reductions. On the other hand, the feed-in tariff（FIT）program that began in 2013 triggered explosive growth of renewable power sources, particularly photovoltaic generations because of its short lead-time and high tariff level. However, mass introduction of renewable power sources causes serious instability issues in power systems. One of these issues is that the mass introduction impacts to the transient stability in power systems. Since it could lead to a massive blackout in the worst case, the power system must be very carefully managed to maintain the transient stability. Another issue is that outputs of photovoltaic and wind power generations fluctuate, causing frequency instability. These fluctuations must be absorbed so as to keep stable frequency in each power system, which is called LFC, load frequency control. Issues on LFC are omitted in this article due to the page limit. In this article, we introduced the constraints on the transient stability in the power generation mix in Kyushu region, taking massive installation of photovoltaic systems into consideration. Next we described on our mathematical model of economic load dispatch for Kyusyu district, taking transient stability into consideration. Computed results quantified suppression of photovoltaic generation in each primary grid, and indicated that the suppression concentrated on specific power transmission lines. Furthermore we investigated the way to efficiently utilize the suppressed power, including estimation of economic feasibility to produce hydrogen utilizing electrolysis.

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Hydrogen is a secondary energy that can be produced from various kinds of primary and renewable energies, that emits no environmental emissions at its use phase and that can be applied to variety of technologies. In terms of the environmental advantages of hydrogen, however, the conventional counterpart technologies that are competitive with hydrogen technologies differ by the purpose of utilising hydrogen. Moreover, the hydrogen supply chain cannot be completely zero emissions due to energies and materials inputs to the processes comprising the supply chain. This article describes the points of attention when evaluating the value of hydrogen from life cycle perspective and introduces the results of life cycle GHG emissions associated with intercontinental supply chain of hydrogen from renewables using energy carriers to address issues for conducting life cycle inventory analysis of hydrogen.

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The objective of this article is to clarify the current status and issues of risk assessment for transporting hydrogen from production facility to hydrogen station for fuel cell vehicles. These clarifications were conducted through the comparison of hydrogen and dangerous materials transport in risk assessment studies. Hydrogen is one of the dangerous materials. Its transport to hydrogen station is still validation phase as against well-established dangerous materials transport. The risk assessment for hydrogen transport hence has the same framework as that for dangerous materials transport. As in the framework, there are the accident scenario creating, risk analysis, risk evaluation, and risk reduction. The difference in hydrogen and dangerous materials transport exists in accident scenario creating and risk analysis. In terms of creating accident scenario, hydrogen transport targets at virtual hydrogen supply system while dangerous materials transport targets at specific transport route. Risk analysis for hydrogen transport is based on a qualitative analysis whereas that for dangerous materials transport covers both qualitative and quantitative analysis. The issues of risk assessment for hydrogen transport are divided into two parts. The first part is the redefinition of risk associated with hydrogen transport. Risk assessment for hydrogen transport need to explore not only engineered risk but also psychological and social risk, such as social disorder and security. The second part is to close a gap between hydrogen and dangerous materials transport in risk assessment. Therefore, future risk assessment for hydrogen transport needs to create accident scenario suitable for unknown system and to effectively-use rich accident data for dangerous materials transport.

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Objective. In the construction industry, a large percentage of the disposed material parts, such as concrete and wood, are recycled in accordance with the “Construction Material Recycling Law.” Similar laws govern the recycling policies in other industries. PVC pipes are recycled by the “Japan PVC Pipe and Fittings Association” in Japan, and most of the recycled material is exported. Thus, observing the trends of the recycling system prevailing in East Asia, the aim of this research is to quantitatively comprehend the situation of the recycling system in Japan. In this study, we examine the PVC scrap material flow in Japan and other East Asian countries and quantitatively evaluate the PVC emissions and utilization of the recycled materials in each country.
Results and Discussion. In this paper, we analyze the material flow of PVC products by investigating the amount of PVC production, emission, recycling, and final disposal. Firstly, we examined the amount of PVC produced in each country. PVC pipes are one of the main PVC products, with approximately 20% to 30% demand. On the other hand, the demand for PVC window frames differs in each country. In Korea and China, the frame is a popular product; however, in Japan and Taiwan, there is little demand. Secondly, we estimated the amount of emission. PVC scrap emissions in Japan peaked at 1,310 kton in 1999 and dropped to 1,180 kton in 2011. In Korea, they peaked at 600 kton in 2008 and dropped to 550 kton in 2011, whereas in Taiwan, they peaked at 900 kton in 2000 and dropped to 520 kton in 2011. The demand in China is rapidly increasing. The Chinese emission amounts have been the largest among the four countries since 1999. The Chinese emissions were 7,110 kton in 2011. Finally, we examined the amount of recycling and final disposal. In Japan, 11% of the total emissions are collected and recycled; 8% of the collected emissions are exported, and 3% are used as recycled material. Finally, 89% of the total emissions are disposed. In contrast, other East Asian counties, such as Korea and China, established a recycling system to manage the emitted scrapped PVC materials. In addition, they import recycled materials. Therefore, the status on PVC emissions’ management differs between these countries because of the differences in their emission problems and demands for PVC materials. While Korea and China focus on demand, Japan adopts policies that focus on the amount of emissions.
Conclusions. The present analysis of the material flow reveals that a large amount of scrapped PVC materials emitted in Japan are exported and used in other East Asian countries. This system is affected by the demand in other countries. Therefore, reconstructing the rigid PVC recycling system of Japan should target the recycling situation of East Asia as a whole.

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