Risk Analysis Based on the Criticality Classes and Their Determination Using Accelerating Rate Calorimetry

Abstract

The scope of this paper is to incorporate thermokinetic parameters determined by Accelerating rate calorimetry (ARC) into risk analysis framework. This approach provides a reliable way for identification and consequent prevention of the risks resulting from the thermal hazards of the assessed processes. ARC is used to determine adiabatic temperature rise (ΔTad), self-accelerating decomposition temperature (SADT) and time to maximum rate (TMR). The other two temperatures are known from the process characteristics: process temperature (Tp) and maximal temperature for technical reasons (MTT). The relation among these temperatures determines the critical class of an assessed process. Event tree analysis (ETA) was used to construct the prefinished event tree for every particular class, which universally describes developments of thermal runaway scenarios. The critical scenarios are consequently analysed using Layer of protection analysis (LOPA) in order to obtain probability of a particular scenario. New method is demonstrated on phenol plant explosion, where the explosion of cumene hydroperoxide (CHP) occurred.