An experimental and modeling study of methyl propanoate pyrolysis at low pressure

Methyl propanoate (MP) pyrolysis in a laminar flow reactor was studied at low pressure (30 Torr) within the temperature range from 1000 to 1500 K. About 30 products were detected and identified in the pyrolysis process using the photoionization mass spectrometry, including H2, CO, CO2, CH3OH, CH2O, CH2CO, C1 to C4 hydrocarbons and radicals (such as CH3, C2H5 and C3H3). Their mole fraction profiles versus temperature were also measured. For the unimolecular dissociation reactions, the rate constants were calculated by high precision theoretical calculations. Based on the theoretical calculations and measured mole fraction profiles of pyrolysis species, a kinetic model of MP pyrolysis containing 98 species and 493 reactions was developed. The model simulates the primary decomposition process well with the calculated rate constants. According to the rate of production analysis, the decomposition pathways of MP and the formation channels of both oxygenated and hydrocarbon products were discussed. It is concluded that the main decomposition pathway is MP → CH2COOCH3 → CH3CO + CH2O → CO.