From 2014 to 2018 Bunro Shiozawa served as Deputy Program Director of the SIP “Energy Carriers” initiative in Japan. Over the last year he has published a ten-part series of articles that describe and reflect on the research supported by the initiative. Part 4 covers ammonia combustion technologies. The first half of the article was posted on September 23, 2020, in Shiozawa's English translation. The second half follows.

ANNOUNCEMENT: The Japanese Government’s Cabinet Office and the Japan Science and Technology Agency have released an English-language video that summarizes the accomplishments of the Cross-Ministerial Strategic Innovation Promotion Program’s Energy Carriers initiative.  The release coincides with the end-of-March conclusion of Energy Carriers’ work, and anticipates this month’s formal activation of the Green Ammonia Consortium.

Hydrogen is the primary fuel source for fuel cells. However, the low volume density and difficulty in storage and transportation are major obstacles for the practical utilization. Among various hydrogen carriers, ammonia is one of the promising candidates because of its high hydrogen density and boiling point and ease in liquefaction and transportation. The reaction temperature of ammonia cracking to nitrogen and hydrogen, being about 600°C or higher, is close to the operating temperature of solid oxide fuel cells (SOFCs). The integration of these two devices is beneficial in terms of heat and energy managements and will lead to the…

Hydrogen is the primary fuel source for fuel cells. However, the low volume density and difficulty in storage and transportation are major obstacles for the practical utilization. On-site generation of hydrogen from its carrier is an effective method for the fuel supply. Among various hydrogen carriers, ammonia is one of the promising candidates. Ammonia has high hydrogen density. The boiling point of ammonia is relatively high, leading to the ease in liquefaction and transportation. Hydrogen can be produced from ammonia with a mildly endothermic process. The reaction temperature of ammonia cracking is about 600˚C or higher which is close to…

To demonstrate the progress of the SIP "Energy Carriers" program, the Japan Science and Technology Agency last week released a video, embedded below, that shows three of its ammonia fuel research and development projects in operation. R&D is often an abstract idea: this video shows what it looks like to generate power from ammonia. As it turns out, fuel cells aren't hugely photogenic. Nonetheless, if a picture is worth a thousand words, this will be a long article.

In the last 12 months ... In July 2017, 19 companies and three research institutions came together to form the Green Ammonia Consortium. Before this development, it was unclear whether ammonia would find a significant role in Japan’s hydrogen economy. In the wake of this announcement, however, ammonia seems to have claimed the leading position in the race among potential energy carriers.

Earlier this month the Eguchi Laboratory at Kyoto University announced advances in ammonia-fueled solid oxide fuel cell technology.  The lab was able to produce a functioning fuel cell with a power output of one kilowatt.  The device attained “direct current power generation efficiency” in excess of 50% and reached 1,000 hours of continuous operation.

Ammonia is a promising hydrogen carrier because of its high hydrogen density, low production cost, and ease in liquefaction and transport. Ammonia decomposes into nitrogen and hydrogen through a mildly endothermic process. The ammonia decomposition temperature is close to the operating conditions of solid oxide fuel cells (SOFCs). Therefore, the integration of these two devices is beneficial in terms of efficient heat and energy managements and will lead to the development of simplified generation systems. We have investigated three types of ammonia-fueled SOFC systems. In one system, ammonia is directly supplied to the anode chamber. Ammonia decomposes into nitrogen and…

Current progress in development of NH3-fueled solid-state fuel cell systems T. Okanishi*, K. Okura, J. Yang, H. Muroyama, T. Matsui, M. Kishimoto, M. Saito, H. Iwai, H. Yoshida, K. Eguchi, Kyoto University; H. Iwai, K. Inaoka, S. Suzuki, Y. Takahashi, Noritake; T. Horiuchi, H. Yamasaki, Nippon Shokubai; S. Matsumoto, H. Kubo, Toyota Industries; J. Kawahara, A. Okabe, Mitsui Chemical; Y. Kikkawa, T. Negishi, S. Watanabe, Tokuyama