THERMAL-STABILITY ANALYSIS VIA ELUCIDATION OF HAZARDOUS REACTION STOICHIOMETRIES

Many accidents that occur in the chemical processing industries such a s thermal runaways are due to unstable reactive systems. A good unders tanding of these systems requires knowledge of the stoichiometries of the reactions that lead to instabilities, which are typically decompos itions and/or polymerizations. A screening test to elucidate these sto ichiometries is presented. It eliminates implausible stoichiometries f rom a candidate set due to their thermodynamic infeasibility. We use c omputational chemistry coupled with statistical thermodynamics to esti mate the thermodynamic properties of the unfamiliar species typically involved in such reactions. The real life runaway due to product insta bility in a process to manufacture tetrahydrofurfuryl benzenesulfonate is treated as a case study. Hartree-Fock and Density Functional Theor y calculations are performed to test for thermodynamic feasibility, le ading to several postulated stoichiometries corresponding to hazardous thermal decomposition. (C) 1998 Elsevier Science Ltd. All rights rese rved.