High-Temperature Dissociation of Neopentanol: Shock Tube/Photoionization Mass Spectrometry Studies

Abstract

The pyrolysis mechanism of 2,2-dimethyl­propan-1-ol (neopentanol) has been investigated at high temperatures (1128–1401K) and high pressures (5 and 15 bar). The experiments were performed in a miniature shock tube coupled to a time-of-flight mass spectrometer. Cations were generated by tunable vacuum ultraviolet photoionization resulting in multidimensional data sets containing mass and photoionization spectra and the time histories of species. At the elevated temperatures and pressures of this work, neopentanol was determined to dissociate primarily by the scission of a C–C bond yielding tert-butyl and hydroxymethyl radicals. These promptly form isobutene and formaldehyde by H-atom elimination. In the structurally similar molecule neopentane, roaming radical reactions have previously been found to be important under conditions close to the present work (1260–1459 K, 1.1 bar). There are two possible roaming radical reactions for neopentanol. However, no experimental evidence for these reactions was found at the elevated pressures in this study, and the dissociation of neopentanol is dominated by bond scission yielding radical products.

Combustion in a Sustainable World: From Molecules to Processes

“…21 The pyrolysis of neopentanol, a further alternative alcohol fuel, was investigated by Banyon and Tranter in a miniature shock tube coupled to a time-of-flight mass spectrometer. 22 Although roaming radical reactions had previously been identified for the structurally similar neopentane, the authors found no experimental evidence for these reactions in the pyrolysis of neopentanol at the studied pressures of 5 and 15 bar. 22 Low-temperature reactions in the oxidation of limonene, a potential biojet fuel, and the formation of highly oxygenated intermediates is the subject of the contribution by Dbouk et al 23 They used a sophisticated combination of Fourier transform infrared spectroscopy and high-resolution Orbitrap mass spectrometry with either electrospray ionization or atmospheric pressure chemical ionization, upon direct injection or after prior separation by ultrahigh-performance liquid chromatography, to identify a large number of C x H y O z species with up to five oxygen atoms.…”

“…Burnett et al studied the pyrolysis chemistry of 2-propanol, a promising alternative fuel in the alcohol family, in a rapid compression machine at elevated pressures and moderate temperatures, using fast-gas sampling and gas chromatography for species detection . The pyrolysis of neopentanol, a further alternative alcohol fuel, was investigated by Banyon and Tranter in a miniature shock tube coupled to a time-of-flight mass spectrometer . Although roaming radical reactions had previously been identified for the structurally similar neopentane, the authors found no experimental evidence for these reactions in the pyrolysis of neopentanol at the studied pressures of 5 and 15 bar …”

“…The pyrolysis of neopentanol, a further alternative alcohol fuel, was investigated by Banyon and Tranter in a miniature shock tube coupled to a time-of-flight mass spectrometer . Although roaming radical reactions had previously been identified for the structurally similar neopentane, the authors found no experimental evidence for these reactions in the pyrolysis of neopentanol at the studied pressures of 5 and 15 bar …”