Thermal Decomposition of 2-Pentanol: A Shock Tube Study and RRKM Calculations.

A single pulse shock tube was used to study the thermal decomposition of 2-pentanol in the temperatures between 1110 and 1325 K. Three major decomposition products are methane, ethylene, and propylene. The minor products detected in lower concentration are ethane, acetylene, acetaldehyde, 1-pentene, and 2-pentene. The rate coefficient for the overall decomposition of 2-pentanol was found to be k(1110-1325 K) = (4.01 ± 0.51) × 10 exp(-(36.2 ± 4.7)/RT) s, where the activation energies are given in kcal mol. To simulate reactant and product distribution over the experimentally studied temperatures between 1110 and 1325 K, a reaction scheme was constructed with 34 species and 39 reactions. In addition to this, the temperature and pressure dependent rate coefficients were computed for various unimolecular dissociation pathways using RRKM theory. The high pressure limit rate coefficient for overall decomposition of 2-pentanol was obtained to be k(500-2500 K) = (9.67 ± 1.11) × 10 exp(-(67.7 ± 2.9)/RT) s. The calculated high pressure rate coefficients and experimentally measured rate constants are in good agreement with each other. The reaction is primarily governed by the unimolecular elimination of water.