Characterizing the autoignition behavior of simple paraffins and alcohols; comparisons and implications

Abstract

Autoignition temperature is defined as the minimum temperature at which a fuel will spontaneously combust in air without an ignition source. Although autoignition temperatures are essential information for the safe handling of fuels, reported literature values are widely variable. In the context of process safety, the need for an improved understanding of autoignition phenomenon is made apparent by the continuing occurrence of autoignition incidents in the process industries. This publication seeks to address some shortcomings in the combustion literature with respect to this topic. In this study, the autoignition characteristics of three paraffins and three alcohols were determined using the ASTM E659 method. In particular, each fuel's autoignition temperature was determined in both quartz and borosilicate test flasks. In the case of each fuel, autoignition temperatures were found to be independent of glassware and well within the margins of experimental error and the spread in reported literature values. Although autoignition temperatures for each fuel were consistent between flask types, this study shows that some fuels' overall ignition behavior changed between quartz and borosilicate glassware. To that end, this work presents shortcomings in the ASTM E659 standard and provides suggestions for improvements.