Comparison of thermal breakdown in coal pyrolysis and liquefaction

摘要: Abstract The courses of the thermal breakdown reactions in coal pyrolysis and liquefaction were compared using similar maceral concentrate samples parallel experiments. A wire-mesh a flowing-solvent reactor used, both reactors providing for rapid removal products from reaction zone order to suppress secondary reactions; product structures therefore expected be relatively free reactor-related effects. An attempt was made distinguish between effects density, solvent power donor ability media surrounding particles during breakdown. Products characterized by size exclusion chromatography, u.v.-fluorescence FT-i.r. spectroscopy. results suggest that sensitivity yields changes heating rate is related competing rates volatile release resolidification within pyrolysing mass: presence locally available hydrogen — e.g. species appears shift this competition favour greater slower resolidification. This explains absence direct effect on at high tetralin:coal ratios. Broad similarity found hexadecane experiments, where sample those ‘dry’ observed. Molecular mass distributions extending higher levels observed extracts than tars; however, it remains possible aromatic nuclei with ranges cluster sizes original may tar extract molecules.