Combustion characteristics of hydroretorted Alabama oil shale

摘要

Pressurized fluidized-bed hydroretorting of beneficiated Eastern US oil shale leaves sufficient carbon (15 to 27 wt %) in the retorted shale to warrant utilization of that calorific value by combustion. A sample of 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(degrees) to 1080(degrees)C, 0.1 to 7 MPa and residence times from 1 to 30 minutes in a thermobalance unit and a continuous (0.5 kg/h) fluidized-bed laboratory-scale unit. Thermobalance tests indicate that combustion of the shale begins at 260(degrees) to 315(degrees)C depending on the oxygen partial pressure used. Carbon conversions up to 100% with greater than 99.5 % recovery of the gross calorific value of the shale were achieved.