Thermal Runaway Hazards of Cumene Hydroperoxide with Contaminants

Cumene hydroperoxide (CHP) has been used in producing phenol and acetone by catalytic cleavage and as an initiator in polymerization. However, many severe fires and explosions have occurred because of its thermal instability and incompatibility. In fact, CHP has been given a hazard classification of flammable type or Class III by the National Fire Protection Association (NFPA). To date, however, its reactive and incompatible hazards have not yet been clearly identified. In this study, the thermal decomposition and runaway behaviors of CHP with about 1 wt % incompatibilities such as H2SO4, HCl, NaOH, KOH, Fe2O3, FeCl3, and Fe2(SO4)3 were analyzed by DSC thermal analysis and VSP2 adiabatic calorimetry. The thermokinetic data obtained via calorimetry, such as onset temperature, heat of decomposition, adiabatic temperature rise, and self-heat rate, were also compared with those of CHP in cumene. Hydroxide ion and ferric ion were found to be quite incompatible with CHP. The worst case of thermal runaway of CHP was observed when it was mixed with hydroxides (in the production or storage of CHP). The adiabatic self-heat rate of 15 wt % CHP was 9 °C min-1 in VSP2, which increased quite dramatically to a value of 100 °C min-1. This study reveals that thermal hazards of CHP influenced by incompatibilities should not be overlooked. The different thermokinetic data affected by the incompatibilities are the key issues for ERS (Emergency Relief System) design in CHP-related processes using DIERS technology. The decomposition pathway of CHP in various impurities was proposed by use of chromatography in product analyses.