Abstract: i-Butanol (iC(4)H(9)OH) pyrolysis has been studied in a flow reactor with synchrotron vacuum ultraviolet photoionization mass spectrometry combined with molecular-beam sampling technique. The pyrolysis species were identified and their mole fractions were determined. Three pressures of 30, 150 and 760 Torr were selected to study the pressure effect of i-butanol chemistry. A detailed kinetic model consisting of 186 species and 1294 reactions was developed to simulate i-butanol high temperature chemistry. To enhance the accuracy, the model was further validated by the species profiles in shock tube pyrolysis, laminar premixed flames, oxidation data from jet-stirred reactor, ignition delay times, and flame speeds. Good agreement between the predicted and measured results was obtained. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.