Pyrolysis Study of Rice Husk and Rice Straw by Vacuum Ultraviolet Photoionization Mass Spectrometry

The pyrolysis of rice husk and rice straw were studied by tunable synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV PIMS). Main pyrolysis products of rice husk and rice straw were identified with mass spectra obtained at different photon energies. The work investigated the relation between pyrolysis products and reaction temperature, according to the mass spectra of rice husk and rice straw pyrolysis at different temperatures. Although the TGA spectra showed that the tendency of the TGA spectra of rice husk and rice straw were similar, their mass spectra were different obviously, especially that the m/z 96 and m/z 114, which came from the pyrolysis of hemicellulose, changed with temperature differently. The time-dependent profiles of some characteristic products showed that the pyrolysis products from hemicellulose appear rapidly at low temperature, while large proportion of lignin underwent slower thermal decomposition at wider temperature range during the overall pyrolysis process.