FLASH PYROLYSIS OF COAL SUB-STRUCTURES ADSORBED ON A CARBOSIEVE

Model compounds representing coal sub-structures have been pyrolyzed adsorbed on a carbosieve, which is suggested to mimic the coal matrix. The adsorption apparently diminishes the vapour pressure of the model compounds, enabling the subsequent flash pyrolysis. The carbosieve does not influence the eventual product distribution. Its material donates only minor amounts of hydrogen and carbon to reactive intermediates during the pyrolysis process. Thus, the application of the technique apparently is rather advantageous for studies of pyrolytic reactions of compounds exhibiting medium to high volatility. Reactions, including mechanistic studies, are investigated by pyrolysis-gas chromatography/mass spectrometry in combination with deuterium labelling of selected sub-structures. The applicability of the technique is illustrated with selected examples, comprising benzene, phenol, benzoic acid, thiophenol and phenyl azide.