COMBUSTION CALORIMETRY OF OIL SHALES

Samples of raw oil shale and spent shale from combustion-retorting experiments are burned in a calorimeter to determine their heats of combustion. The shales are mixed with an equal amount of benzoic acid to achieve complete combustion. A platinum crucible with a basket is used to allow minimal contact of sample with platinum. This design reduces quenching effects by permitting oxygen to completely surround the sample. The heats of combustion, -ΔHc, for raw shale range from 1150 to 1250 cal g-1 while those for spent shale range from -65 to -15 cal g-1. The precision of the analysis gives a standard deviation of approximately 5 cal g-1. Uncertainties in the sulfur correction and the gas correction, Δn, have the largest effect on the accuracy of the analysis. © 1979.