Experimental and kinetic modeling study of benzyl alcohol pyrolysis

摘要

The pyrolysis of benzyl alcohol (A1CH_2OH) at 30 and 760 torr was studied in a flow tube reactor. The synchrotronradiation photoionization and molecular-beam mass spectrometry (MBMS) techniques were usedto identify and quantify 35 intermediates and products including some small species, several monophenylring species, and a large number of polyaromatic hydrocarbons (PAHs). A comprehensive chemical kineticreaction model involving 376 species and 2171 reactions was developed with reasonable prediction. Accordingto the rate-of-production analysis, the consumption of A1CH 2 OH is mainly proceeded with theH-abstraction reactions with H atoms and OH radicals under both pressures. H-abstractions and unimoleculardissociation dehydrogenation reactions also play important roles in the subsequent formationof PAHs. Phenyl radicals, benzene (A1), and benzyl (A1CH_2 ) radicals are important intermediates in thepyrolysis of A1CH_2 OH, which provide various ways for the formation of PAHs. Sensitivity analysis presentsthat the most significant sensitive reaction of A1CH_2 OH consumption is the unimolecular initiation reactionby the C –O bond breaking from A1CH 2 OH under both pressures. The combination of A1CH_2 radicalswith H atoms to form toluene (A1CH 3 ) has the most inhibiting influence on the A1CH 2 OH consumptionunder both pressures, while it has little sensitive effects for the oxidation process of A1CH_2 OH consumption.The comparison of the A1CH_2 OH pyrolysis and oxidation results show that the peak mole fractionsof A1 increase, while the peak mole fractions of phenol (A1OH) decrease with the increase of equivalenceratio ( ?) under the same pressure. It should be noted that the peak mole fractions of benzaldehyde(A1CHO) are relatively stable with various conditions. These results provide a theoretical basis for furtherstudy of the combustion chemical kinetics of A1CH_2 OH and its application in bio alternative fuel.