Exploring the Potential of HFC-125a Hydrate for Innovative Fire Suppression: A Gas Hydrate Technology Approach

Abstract

This study explores the applicability of gas hydrate technology as an innovative approach to fire suppression, focusing on the novel use of HFC-125a hydrate as a superior retardant for class B liquid fires. Two sequential steps were performed, involving the novel formation and pelletization of HFC-125a hydrate with an emphasis on the significance of subcooling on formation kinetics. We achieved a 15% hydrate conversion in 9 min and 70% within 19 min for pelletization. Raman spectra revealed HFC-125a encapsulation in large 5 12 6 4 hydrate cages. Flame suppression tests, conducted in small pool fire (lab-scale) and pool fire (practical) setups, demonstrated the exceptional fire suppression capabilities of HFC-125a hydrate powder (0.1−0.5 mm) compared to conventional NH 4 H 2 PO 4 and ice powders. Notably, the HFC-125a hydrate powder successfully prevented reignition, unlike NH 4 H 2 PO 4 . In the pool fire system, the HFC-125a hydrate powder outperformed a commercialized aerosol. A novel gun-type sprayer facilitated the application of hydrated powder on a fire flame, showcasing practical feasibility. The mechanism involves the endothermic nature of the hydrate absorbing heat and releasing encapsulated HFC-125a gas upon disintegration. This gas retorts to remove oxygen, creating an uninhabitable atmosphere for combustion and effectively preventing reignition. Overall, this study establishes the feasibility of gas hydrate-based technology, specifically the use of novel HFC-125a hydrates in powder form, as a promising fire suppression agent. The findings provide insights for the future development of hydrate-based fire extinguishment methods.