Experimental and kinetic modeling studies of phenyl acetate pyrolysis at atmospheric pressure

Abstract

Phenyl acetate (CH3COOC6H5, PA) shares a similar aryl acetate group with vitamin E acetate, which is thought to be responsible for producing pulmonary toxic ketene in e-cigarettes. Hence, PA is reported to be a model compound of vitamin E acetate in producing ketene. To better understand the pyrolysis chemistry of vitamin E acetate, pyrolysis of PA in a jet-stirred reactor was investigated by using synchrotron vacuum ultraviolet photoionization mass spectrometry at atmospheric pressure and at temperature range of 700 – 1025 K. Several key products such as acetylene, ethylene, carbon monoxide, formaldehyde, carbon dioxide, vinyl acetylene, 1,3-butadiene, 1,3-cyclopentadiene, benzene, phenol, etc., and especially, ketene, were identified and measured. By extending the phenyl formate pyrolysis model, a detailed PA pyrolysis model containing 735 species and 3365 reactions was constructed and validated against the current experimental results of PA pyrolysis. Rate of production analysis and sensitivity analysis show that the main reaction pathways of PA pyrolysis are the unimolecular decomposition forming phenol and ketene, followed by the C–CH3 bond cleavage forming phenoxycarbonyl and methyl. The corresponding products of these two reactions and of the subsequent reactions, including phenol, ketene and carbon monoxide, etc., are demonstrated to be the key products in PA pyrolysis. Toxic aromatic compounds, such as benzene, toluene and ethylbenzene, etc., also have relatively high mole fractions in PA pyrolysis.