The reaction pathway analysis of phosphoric acid with the active radicals: a new insight of the fire-extinguishing mechanism of ABC dry powder
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Dry powder fire-extinguishing agent is one of Halon substitutes due to its superior fire-extinguishing performance, non-toxicity, and environmental friendliness. As one of the most widely used dry powders, ABC dry powder has attracted wide attention. Understanding its reaction mechanism is important to the design of more efficient compound dry powder based on it. When ABC dry powder was applied to the flame, ammonium dihydrogen phosphate (the main fire-extinguishing component of ABC dry powder) would rapidly decompose into phosphoric acid (H3PO4) and ammonia. Therefore, in order to figure out the chemical reaction mechanism of ABC dry powder and active radicals, the main focus of this paper is on the H3PO4. Analysis of the electrostatic potential on van der Waals surface of H3PO4 was carried out. Besides, detailed theoretical investigation has been performed on the mechanism, kinetics, and thermochemistry of the reactions of H3PO4 with H, OH, and CH3 radicals and further decomposition of H3PO4 using M06-2X/6-311G(d,p)//CCSD(T)/cc-pVTZ level of theory. Mayer bond order for all intrinsic reaction coordinate points was also calculated. Finally, it is theoretically proved that ABC dry powder extinguishes the fire mainly by chemical inhibition on H and OH radicals.
KeywordsABC dry powder Thermal decomposition H3PO4 Reaction mechanism Fire suppression mechanism
We are grateful to the High-Performance Computing Center of Nanjing Tech University for supporting the computational resources.
This work was supported by the National Natural Science Foundation of China (No.51704171), Postdoctoral Science Foundation of China (General Program) (No. 2016M601796), Planned Projects for Postdoctoral Research Funds of Jiangsu (No. 1601033C), Six Talent Peaks Project of Jiangsu (No. 2014-XCL-010), and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
- 1.Steacie EWR (1954) Atomic and free radical reactions2nd edn. Reinhold Pub, CorpGoogle Scholar
- 2.Burden MC, Burgome JH and Weitierg FJ, Weinberg (1955) The effect of methyl bromide on the co’nhstion of some fuel-air mixtures. Paper presented at Fifth Symposium (International) on Conibustion. Uuiv. RLttsbuxgh, Aug. 30-Sept. 5.1. 647–651. https://doi.org/10.1016/S0082-0784(55)80089-6 CrossRefGoogle Scholar
- 3.Tapscott RE (1987) The ozone impact mitigation program, annual meeting of the national. Fire Protection Association, Cincinnati, Ohio, USAGoogle Scholar
- 4.Mather JD, Tapscott RE (1999) Tropodegradable halocarbons and main group element compound. Proceeding of halon options technical working conference. Albuquerque, NM, USAGoogle Scholar
- 10.Ewing CT, Faith FR, Romans JB, Hughes JT, Carhart HW (1992) Flame extinguishment properties of dry chemicals: extinction weights for small diffusion pan fires and additional evidence for flame extinguishment by thermal mechanisms. J. Fire. Prot. Eng. 4:35–51. https://doi.org/10.1007/BF01041422 CrossRefGoogle Scholar
- 11.Brooks J, Berezovsky J, Dwyer MO (2002) Aerosol fire suppression for high rise structural applications via aircraft distribution using metalstorm technologies. Proceedings of halon options technical working conference (HOTWC). Albuquerque, NM, NIST SP 984Google Scholar
- 24.Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Scalmani G, Barone V, Petersson GA, Nakatsuji H, Li X, Caricato M, Marenich AV, Bloino J, Janesko BG, Gomperts R, Mennucci B, Hratchian HP, Ortiz JV, Izmaylov AF, Sonnenberg JL, Williams-Young D, Ding F, Lipparini F, Egidi F, Goings J, Peng B, Petrone A, Henderson T, Ranasinghe D, Zakrzewski VG, Gao J, Rega N, Zheng G, Liang W, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Throssell K, Montgomery Jr JA, Peralta JE, Ogliaro F, Bearpark MJ, Heyd JJ, Brothers EN, Kudin KN, Staroverov VN, Keith TA, Kobayashi R, Normand J, Raghavachari K, Rendell AP, Burant JC, Iyengar SS, Tomasi J, Cossi M, Millam JM, Klene M, Adamo C, Cammi R, Ochterski JW, Martin RL, Morokuma K, Farkas O, Foresman JB, Fox DJ (2016) Gaussian 16, revision A.03. Gaussian, Inc., Wallingford CTGoogle Scholar
- 28.Mishra BK, Lily M, Chandra AK, Bhattacharjee D, Deka RC, Chandra AK (2014) Theoretical investigation of atmospheric chemistry of volatile anaesthetic sevoflurane: reactions with the OH radicals and atmospheric fate of the alkoxy radical (CF3)2CHOCHFO: thermal decomposition vs. oxidation. New J. Chem. 38:2813–2822. https://doi.org/10.1039/C3NJ01408H CrossRefGoogle Scholar
- 30.Gour NK, Deka RC, Singh HJ, Mishra BK (2014) Theoretical studies on kinetics, mechanism and thermochemistry of gas-phase reactions of CF3CHFCF2OCF3 with OH radicals and Cl atoms and fate of alkoxy radical at 298 K. J. Fluor. Chem. 160:64–71. https://doi.org/10.1016/j.jfluchem.2014.08.001 CrossRefGoogle Scholar
- 39.Opoku F, Asare-Donkor NK, Adimado AA (2015) Theoretical studies of the decomposition of Zn[(iPr)2PSSe]2 single-source precursor in the gas phase for the chemical vapor deposition of binary and ternary zinc chalcogenides. Comput Theor Chem 1058:1–11. https://doi.org/10.1016/j.comptc.2015.01.020 CrossRefGoogle Scholar
- 43.Bridgeman AJ, Cavigliasso G, Ireland LR, Rothery J (2001) The Mayer bond order as a tool in inorganic chemistry. J Chem Soc Dalton Transactions. https://doi.org/10.1039/B102094N
- 45.Ruscic B, Litorja M, Asher RL (1999) Ionization energy of methylene revisited: improved values for the enthalpy of formation of CH2 and the bond dissociation energy of CH3 via simultaneous solution of the local thermochemical network. J. Phys. Chem. A 103(43):8625–8633. https://doi.org/10.1021/jp992403v CrossRefGoogle Scholar