COMBUSTION CHARACTERISTICS OF HYDRORETORTED ALABAMA OIL-SHALE

Pressurized fluidized bed hydroretorting of beneficiated eastern USA o il shale leaves sufficient carbon (15-27 wt%) in the retorted shale to warrant utilization of that calorific value by combustion. A sample o f hydroretorted shale from a bench scale unit test (oil yield was 233% of Fischer Assay) was used as a feedstock for combustion tests using air. The tests were conducted at 815-1080-degrees-C, 0.1-7 MPa and res idence times from 1 to 30 min in a thermobalance unit and a continuous (0.5 kg h-1) fluidized bed laboratory scale unit. Thermobalance tests indicate that combustion of the shale begins at 260-315-degrees-C dep ending on the oxygen partial pressure used. Carbon conversions up to 1 00%, with greater than 99.5% recovery, of the gross calorific value of the shale were achieved.