Thermal processing of high ash, solid carbonate fuel, esp. oil shale - by mixing with solid heat carrier at high temp.

摘要

The process causes thermal decompsn. of the fuel at 475-500 degrees C, into a vapour/gas mixt. and a solid residue, by mixing with an ash-contg. heat carrier consisting of the solid residue preheated to 870-950 degrees C. Preheating the carrier increases the decompsn. of carbonates present, with formation of CaO and MgO. These combine with acid gases and vapours (H2S, CO2 and phenols boiling at >=350 degrees C) during the thermal decompsn. and reduce their concn. in the prods. In an example, oil shale of 12 mm size is dried and preheated to 120-150 degrees C with flue gas, and mixed with a solid heat carrier preheated to 870-950 degrees C. 33m3 gas contg. only 1.5 vol.% CO2 and no H2S, 13 kg. gasoline and 150 kg. resin contg. 12% phenols are obtd. per tonne shale.