REACTORS, KINETICS, AND CATALYSIS Thermal Decomposition of Cumene Hydroperoxide: Chemical and Kinetic Characterization I. Di Somma, R. Andreozzi, M. Canterino, and V. Caprio Universita ` di Napoli ‘‘Federico II’’, p.le V. Tecchio, 80-80125-Napoli, Italy R. Sanchirico Istituto di Ricerche sulla Combustione (CNR), p.le V. Tecchio, 80-80125-Napoli, Italy DOI 10.1002/aic.11487 Published online April 9, 2008 in Wiley InterScience (www.interscience.wiley.com). Thermal decomposition process of cumene hydroperoxide (CHP) in cumene has been investigated by different researchers from chemical and kinetic point of view although its reactive characteristics have not yet been fully identified. The major dis- crepancy in the literature data is represented by different reaction nth-order and auto- catalytic kinetics suggested. In the present work CHP thermal decomposition is studied by means of isothermal experiments, adiabatic and scanning calometry on commercial hydroperoxide samples. The most simple autocatalytic scheme is adopted for the analy- sis of the data collected on CHP solutions in cumene at different initial concentrations (80%–30% w/w) allowing to estimate the kinetic parameters regulating the process. A characterization of the intermediate and product distribution at varying reaction time is attempted. The effect on the system reactivity of the addition of small quantities of carbinol or acetophenone or a-methylstyrene to the CHP solution in cumene is also studied. Ó 2008 American Institute of Chemical Engineers AIChE J, 54: 1579–1584, 2008 Keywords: cumene hydroperoxide, thermal decomposition, autocatalytic kinetics, decomposition products, calorimetry Introduction Cumene hydroperoxide (CHP) is an important intermediate for the production of phenol (along with acetone) 1 and dicu- mylperoxide. It is also used as an initiator in polymerization processes. 2 It is currently produced through the oxidation with air of cumene. Incidents have been documented in the past in the oxidation reactors, 3 vacuum evaporator 4 and stor- age tanks. 5 For example, Kletz reported that an explosion occurred in an oxidation column when—as a result of a problem to the feed—the liquid inside was left at 382 K without cooling and exploded after 5 h from the beginning of the process deviation. 6 Due to its tendency to undergo vio- lent thermal decomposition, its behavior has been investi- gated by different researchers 3,7 from chemical and kinetic points of view, although its reactive characteristics have not yet been fully identified. In particular the major discrepancy among the literature data is represented by the order of reac- tion for the decomposition of CHP in cumene. Different nth order (n 5 1/2 for Duh et al., n 5 1 for K. Hattori et al.), and autocatalytic kinetics 8 have been proposed, from which no clear indications may be derived when a prediction of the system behavior is required. It is noteworthy to observe that very different data may be obtained for example in the calcu- lation of adiabatic time-to-maximum rate (TMR) of a CHP This article contains supplementary material available via the Internet at http:// www.interscience.wiley.com/jpages/0001-1541/suppmat. Correspondence concerning this article should be addressed to I. Di Somma at idisomma@unina.it. Ó 2008 American Institute of Chemical Engineers AIChE Journal June 2008 Vol. 54, No. 6 1579