Ignition characteristics, conditions of criticality and disappearance of criticality of cumene hydroperoxide reaction by modeling approach

The thermal explosion problem of cumene hydroperoxide exothermic reaction which is used in chemical industries for production of some chemical materials is investigated. The analytical solutions of the problem to determine the margin between ignition and non-ignition systems are presented. The solution offers different analytical expressions which relate between the critical parameters for both steady and unsteady-states in different planes of solutions for different cases. The numerical solutions in different planes offer different trajectories of solution as sub-critical (non-ignition) and supercritical (ignition). Also from the numerical solution the relations between the critical parameters are presented. The critical behaviors from both analytical and numerical solutions are concise and pertained the same results.     

Reconsidering autoignition in the context of modern process safety: Literature review and experimental analysis

Autoignition is regarded as the spontaneous combustion of a fuel without an apparent ignition source. With respect to fires and explosions in the process industries, the autoignition hazard is one that requires management and consideration. Despite the importance of understanding the autoignition hazard, the literature on the topic is often disappointingly sparse and inconsistent. Experimental methods don't adequately represent real-world conditions and are complicated by experimental error, invoking the need for a reconsideration of autoignition as it pertains to process safety. This work utilized the ASTM E659 method to study potential experimental error for the purpose of improving the process safety community's understanding of autoignition phenomena. Of interest to this study were effects of humidity and suspected occurrences of cool flames, two sources of error which have not been fully explained in the literature. For the fuels tested, results show that humidity has only a slight effect on overall autoignition behavior. However, this study's examination of cool flames suggests that they could be a common occurrence in this testing method. Analysis of these experiments show that cool flames can feature significant exothermic effects and are thus of concern from a perspective of risk management. In addition, this work proposes a novel criterion for a more conservative assessment of autoignition experiments, which results in less subjectivity of analysis.