A thermal decomposition study of pine wood under ambient pressure using thermogravimetry combined with synchrotron vacuum ultraviolet photoionization mass spectrometry

As pyrolysis is the initial step involved in thermochemical processes of biomass, understanding of the pyrolytic behavior of biomass is crucial to biomass thermochemical conversions. This work presents a new facility for studying the pyrolysis behavior of solid fuels. The experimental setup contains a thermogravimetry system connected with a home-made reflectron time-of-flight mass spectrometer via a single-stage molecular beam sampling interface, and a tunable vacuum ultraviolet (VUV) light generated from synchrotron source is used for soft photoionization. Evolution of the gaseous products of pine wood pyrolysis was examined at a heating rate of 20°C/min in a nitrogen environment at atmospheric pressure. Experiments were performed at the photon energies of 10.0, 10.5 and 11.0 eV, and mass spectra of gaseous products were recorded by the time-of-flight mass analyzer every five seconds. Species with the mass range of m/z 20–220 are presented and possible formation pathways of typical products are discussed.