New approach to the characterization of pyrolysis coal products by gas chromatography-mass spectrometry

Abstract A method for the characterization of coal thermal behaviour, based on gas chromatographic-mass spectrometric analysis of the pyrolysate, is presented. Twelve different coal samples, representative of the entire coal rank, were selected for this study. The pyrolysis products, obtained at 800°C, were first collected and then analysed in two GC-MS systems. The sampling apparatus consisted of three different traps in order to separate the products into three fractions on the basis of their volatility. The GC-MS analysis was also arranged according to this criterion. A packed column, coupled to a double-focusing magnetic mass spectrometer, was used for the volatile fractions of the pyrolysate and a capillary column, coupled to a quadrupole analyser, was employed for the analysis of the condensed fraction. Sampling and analysis procedures were carried out separately, thus allowing careful optimization of the strategy for the characterization of the pyrolysate. The condensate was analysed in the selected-ion monitoring mode for the determination of different classes of compounds. Some evaluations and comparisons, extrapolated from the results obtained, are presented.