Isothermal pyrolysis and char combustion of oil shales

reportYields and rates of hydrocarbons evolved during pyrolysis of oil shales have been measured with improved accuracy. Green River and New Albany oil shales were heated in a fluidized sand bed, and volatile pyrolysis products were transferred to a combustion tube and burned. Resulting H20 and C02 were detected in real time by mass spectrometry. Residual char was subsequently burned to allow complete C and H balances. Good closure was obtained. Proportions of organic C and H released as pyrolysis products and retained as char were determined. Shale oil loss due to the presence of oxidized shale in the fluidized bed was measured accurately. We find that all of the experimental apparatus that the pyrolysis gas contacts must be near pyrolysis temperature to avoid condensation of heavy oil which subsequently forms coke and secondary products. We observe a faster release of products with all transfer lines at 450°C than when they are at 300°C. The current uncertainty in pyrolysis rates is due in part to such difficulties with experimental technique