EFFECTS OF COOKING ON THE THERMAL IGNITION BEHAVIOR OF VEGETABLE OIL

摘要

The Frank-Kamenetskii theory for thermal ignition of self-heating materials is a powerfulrnapproximation that historically has been applied to predict safe storage temperatures. An exothermicallyrnreacting material is at risk of potentially undergoing thermal ignition during storage if it is stored above thernmaterial‟s experimentally determined critical ambient temperature (T_(cr)). This condition can potentially leadrnto runaway reaction of reactive chemicals, or so called “spontaneous ignition” of combustible materials.rnVegetable-derived and some animal-derived oils (i.e., edible oils) are known to be susceptible tornexothermic oxidation of their unsaturated bonds in the component fatty acids. A greater degree ofrnunsaturation (i.e., polyunsaturation) will lead to greater reactivity. Edible oil contamination can be detectedrnin fire debris through fatty acid methyl esters (FAME) analysis, and the degree of unsaturation is used tornqualitatively characterize the material‟s propensity to self-heat.rnAlthough the potential for spontaneous combustion of edible oil-contaminated cellulosic materials is wellknownrnanecdotally, there is a lack of controlled experimentation and predictive methods for estimating therncritical criteria. This paper provides the results of critical ignition temperature analysis for new and usedrncooking oils following the parallel reaction model of Bowes. By applying Bowes‟ method, effective kineticrnparameters for the Frank-Kamenetskii model were determined. Using these parameters and thernconcentration dependence, the critical conditions for edible oil-contaminated cellulosic materials can bernpredicted. The paper will discuss the current results of the testing and analysis.