Fluorescence and Micro-FTIR characteristics of typical liptinite at low temperature thermal conversion

The subgroups and contents of liptinite have significant influence on yields of tar and gas in pyrolysis.The heating stage microscope, fluorescence analysis and Micro-FTIR were used to study the characteristics of typical liptinite at low temperature thermal conversion. The results showed that the relative fluorescent intensities decreased and the maximum fluorescence wavelength increased as the pyrolysis temperature increase. The fluorescence characteristics of resinite and suberinite began to change at 240 ℃, and remarkable changed at 280−320 ℃. The fluorescence characteristics of sporinite, cutinite, and bituminite A began to change at 280 ℃, and remarkable changed at 320−360 ℃. The fluorescence characteristic of alginite began to change at 280 ℃, and lasting changed till 400 ℃. The fluorescence characteristic of bituminite B changed at 320−360 ℃. The absorption peak of aliphatic compound in alginite was strongest, and the peaks of bituminite, resinite, cutinite, and sporinite decreased in turn. The aliphatic compounds and oxygen-containing groups of liptinite group decreased and the content of aromatic hydrocarbon relatively increased as the temperature increase. The aromatization degree of liptinite group was low and basically remain unchanged at low temperature thermal conversion. The hydrogen-rich degrees and the change of aliphatic chains of liptinite group confirmed well with the fluorescence characteristics.