Proposal for accident prevention technology through the elucidation of the initiation mechanism of the chain self-heating decomposition reaction of nitrous oxide

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04483
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Chiba Institute of Technology
• Principal Investigator: Wada Yutaka 千葉工業大学, 工学部, 教授 (20553374)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 亜酸化窒素 / 自己発熱分解 / 分解メカニズム / 触媒

Outline of Final Research Achievements

This study aims to prevent significant incidents in spacecraft by elucidating the sudden explosion phenomena of nitrous oxide, which is anticipated for use in such vehicles. Nitrous oxide possesses a high vapor pressure, and when utilized as an oxidizer for rocket engines, it obviates the need for a pressurization mechanism, thereby simplifying the system. Consequently, we applied thermal energy to nitrous oxide and potential contaminants to investigate the presence or absence of a chain self-heating decomposition reaction. While reactions were observed in hydrocarbons, no self-heating decomposition reaction was found in fluororesin materials. In graphite materials, reactions were more likely to occur with smaller particle sizes, suggesting that the degree of heat transfer within the material influences the reaction. Furthermore, we uncovered the possibility that nitration may promote the reaction.

Free Research Field

航空宇宙工学

Academic Significance and Societal Importance of the Research Achievements

これまで，亜酸化窒素の連鎖的な自己発熱分については炭化水素系の物質と反応することが知られていたが，そのきっかけとなる減少についての言及はなかった．本実験を実施したことにより，炭化水素系の物質の熱分解物質と，亜酸化窒素から遊離した酸素とが反応することがきっかけとなり全体的な亜酸化窒素の連鎖反応につながっていることを突き止めた．連鎖反応のきっかけが，可燃性ガスと酸素との混合気の反応であることを明らかにしたことは本研究が初めてであり，今後亜酸化窒素を用いる際に安全な運用を行うための指標として成果をまとめいてく予定である．