Evaporation and diffusion behavior of fuel mixtures of gasoline and kerosene

• Published in: Fire safety journal 2012-04, Vol.49, p.47-61
• Main Authors: Okamoto, Katsuhiro, Hiramatsu, Muneyuki, Miyamoto, Hiroki, Hino, Tomonori, Honma, Masakatsu, Watanabe, Norimichi, Hagimoto, Yasuaki, Miwa, Koji, Ohtani, Hideo
• Format: Article
• Language: English
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Diffusion; Energy; Evaporation rate; Exact sciences and technology; Fire behavior of materials and structures; Fire protection; Fuels; Gasoline; Kerosene; Vapor pressure
• ISSN: 0379-7112
• DOI: 10.1016/j.firesaf.2011.12.013

Kerosene is widely used in lamps and stoves and is less of a fire hazard than other fuels, such as mineral spirits, due to its flash point being above 40°C and low vapor pressure at normal ambient temperatures. At room temperature and pressure, the concentration of vapor above a kerosene spill is well below the lower flammability limit, but gasoline addition to kerosene will increase the vapor pressure and the ignitability of kerosene. The aim of this paper is to accurately predict the evaporation and diffusion behavior of fuel mixtures of gasoline and kerosene in an arbitrary mixture ratio. While the vapor pressures of gasoline and kerosene, which are both multi-component liquid fuels, decrease with the progress of evaporation, it is demonstrated that the vapor pressures can be expressed by exponential functions of weight loss fractions. The vapor pressures, evaporation rates and flash points of gasoline/kerosene mixtures can be modeled accumrately by treating them as two-component mixtures, using empirically-derived constants for each component, which this paper gives. Furthermore, a predictive model of a concentration distribution of vapor above a fuel mixture spill on a floor was derived. Ignition experiments of fuel vapor were carried out, and the model was experimentally verified. The method presented in this paper can provide useful information to estimate the fire hazard in scenarios where a fuel mixture of gasoline and kerosene in an arbitrary mixture ratio is spilt on a floor. ► An evaporation model of gasoline/kerosene mixtures was presented. ► Clausis–Clapeyron equation was established in fuel mixtures. ► Mass transfer coefficients of fuels were obtained from evaporation tests. ► Flash points of degraded fuel mixtures rose up to around 40°C.