Solid oxide fuel cells with direct internal reforming of ammonia-methane mixed fuel

• Project/Area Number: 21K18689
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Iwai Hiroshi 京都大学, 工学研究科, 教授 (00314229)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000); Fiscal Year 2023: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2022: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2021: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 改質 / 混合燃料 / 固体酸化物形燃料電池 / 燃料極 / 実験

Outline of Research at the Start

固体酸化物形燃料電池(SOFC)にアンモニアと加湿メタンの混合燃料を直接供給することによるSOFCの新規温度制御法の実現性を実験的に明らかにする。典型的なSOFC燃料極であるNi-YSZやNi-GDCの混合多孔質体を主な対象として、アンモニア、メタン、水蒸気の混合ガスを供給し、排出ガスの組成を調べることで燃料極における改質・分解反応の基礎特性を明らかにする。またアンモニアによるメタン水蒸気改質反応の抑制現象の原因を解明する。さらに混合燃料に対する反応速度モデルを提案し、その妥当性を検証する。

Outline of Final Research Achievements

The feasibility of a new operation method for solid oxide fuel cells, in which a mixture of ammonia and methane gas is directly supplied as fuel, was experimentally clarified. This could be a new method to manage the temperature distribution in the cell as well as to make effective use of the excess heat generated from the electrochemical reactions. It was found that the ammonia decomposition reaction proceeds preferentially over the methane steam reforming reaction in the mixed gas, and the oxidation reaction of the produced hydrogen proceeds as the main reaction of the electrochemical reaction.

Academic Significance and Societal Importance of the Research Achievements

本研究を通じて、アンモニア-メタン混合燃料を用いることによる新たなセル温度制御手法の実現性を示すとともに、セル性能予測に必用な混合燃料供給時の起電力のの簡易予測手法を確立した。さらに小型セルによる実験により、発電性能の基礎特性を取得することができた。アンモニアとメタンの組み合わせに限らず、広く混合ガス燃料を直接供給するSOFCの理解が進むことが期待される。

Research Products

• [Presentation] 固体酸化物形燃料電池の燃料極内空隙における水素生成反応がガス輸送及び電極性能に与える影響 (2024)
  • Author(s): 小堀孝文，Guo Yuting， 岸本将史，岩井裕
  • Organizer: 日本機械学会関西支部第99回定時総会・講演会
• [Presentation] Numerical approach to understanding the internal phenomena of solid oxide fuel cells (2023)
  • Author(s): Hiroshi Iwai
  • Organizer: The 9th Asian Symposium on Computational Heat Transfer and Fluid Flow
  • Int'l Joint Research / Invited
• [Presentation] Ni-YSZ燃料極におけるメタン・アンモニア混合燃料の改質・分解特性とOCVの実験的考察 (2023)
  • Author(s): 細溝暉人，Guo Yuting，岸本将史，岩井裕
  • Organizer: 第32回SOFC研究発表会
• [Presentation] Effect of Catalyst Support in Ni-Based Catalysts on Reaction Characteristics of Humidified Methane-Ammonia Mixed Gas (2022)
  • Author(s): Akihito Hosomizo, Sora Nozaki, Masashi Kishimoto, Hiroshi Iwai
  • Organizer: 7th International Conference on Contemporary Problems of Thermal Engineering
  • Int'l Joint Research
• [Presentation] Reaction characteristics of methane-ammonia mixed gas on Ni-based catalysts: effects of catalyst support (2022)
  • Author(s): Sora Nozaki, Akihito Hosomizo, Masashi Kishimoto, Hiroshi Iwai
  • Organizer: 22nd Tsinghua-Seoul National-Kyoto University Thermal Engineering Conference
  • Int'l Joint Research
• [Presentation] Reforming of Methane-Ammonia Mixed Fuel on Ni-based SOFC Anode: Effects of Oxide (2021)
  • Author(s): Sora Nozaki, Masashi Kishimoto, Hiroshi Iwai
  • Organizer: The Second Asian Conference on Thermal Sciences
  • Int'l Joint Research