A W1 computational study on the kinetics of initial pyrolysis of a biodiesel model: methyl propanoate

Abstract

This work reports on the thermochemistry and kinetics of methyl propanoate (MePr) initial pyrolysis using the high ab initio multi-level composite W1 method over the temperature range 400–2000 K. Pyrolysis of MePr was simulated using ten complex bond fission reactions (R1–R10) and seven simple bond fission pathways (R11–R17). Rate coefficients of MePr decomposition have been estimated using transition state theory (TST) combined with tunneling through a one-dimensional Eckart barrier (Eck). Statistical Rice–Ramsperger–Kassel–Marcus (RRKM) tight theory has been also used in a pressure range of 0.001–100 atm. Our estimated rate coefficients are in strong agreement with previous literature and strongly pressure-dependent especially at high temperatures. In addition, thermodynamic parameters for MePr and some species involved in its decomposition reactions have been computed and compared with previous literature.