Study on novel risk assessment for inerting systems under the limiting oxygen concentration

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15249
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 25020:Safety engineering-related
• Research Institution: Fukuoka University (2022); Yokohama National University (2019-2021)
• Principal Investigator: SHIOTA KENTO 福岡大学, 工学部, 助教 (30827837)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: イナーティングシステム / 限界酸素濃度 / 毒性ガス / リスク / 危険性解析

Outline of Final Research Achievements

The objective of this study was to obtain knowledge that will contribute to the proposal of novel risk management methods for inerting systems below the limiting oxygen concentration (LOC). From this study, the behaviour of the formation of toxic gases from the reaction of hydrocarbons such as propane under oxygen concentration conditions below the LOC was identified from calculations and experiments. The findings that contribute to a novel risk assessment method include: the formation of toxic gases such as ammonia when the substance of interest in the process produces saturated hydrocarbons in an inert atmosphere; the fact that the formation behaviour of toxic gases can be easily predicted computationally from the rate of production of saturated hydrocarbons; and the fact that the risk of toxic gases is not limited to acute toxicity but should also include the risk to society in the assessment.

Free Research Field

安全工学関連

Academic Significance and Societal Importance of the Research Achievements

今までの研究では、可燃性ガスを取扱うプロセスにおける不活性ガスを導入し酸素濃度を低くすることで火災・爆発の危険性に着目しているが、本研究はそのような環境下における毒性ガスの生成の挙動や危険性について着眼し、それらについて解析・考察した点に学術的に意義がある。また、今回の研究から明らかになった毒性ガスの生成が及ぼす危険性について、人体・環境への毒性に留まらず社会生活への影響を考慮したとして扱うべきだという点は社会的に意義があり、今後起こりうる自然災害などに起因した複合災害のリスク評価を考えるうえで重要な視点であると考えられる。