Gas production from the pyrolysis of oil shale as affected by Fe 2 O 3

In this study, the effects of Fe2O3 on the formation of noncondensed gas and the higher heating value (HHV) of pyrolysis gas during the pyrolysis of oil shale were studied by using the horizontal tube furnace retorting test bed and Fourier infrared spectrometer. In order to exclude the impact of other mineral matter on oil shale retorting process, this research adopts washing oil shale with HCl-HF-HNO3 to obtain LongKou oil shale organic matter. Based on the ash composition analysis of pyrite, equivalent amounts of Fe2O3 (0, 2.5, 8, 40%), with the same Fe content as pyrite, were directly loaded onto the organics. Research indicates that Fe2O3 can facilitate the decomposition of large molecules in organic matter, resulting in the production of more CO and enhancing the overall HHV of pyrolysis gas. However, excessive amounts of Fe2O3 can lead to the conversion of CO into CO2 and inhibit the formation of C2H6, thereby reducing the HHV of pyrolysis gas. When the addition of Fe2O3 increases from 2.5% to 8%, the gas conversion rate rises from 37.45% to 41.94%, and the maximum HHV of pyrolysis gas also increases from 41.35 to 41.79 MJ/Nm3. Nevertheless, when the addition of Fe2O3 reaches 40%, the maximum HHV of pyrolysis gas drops to only 35.43 MJ/Nm3.