The Fischer assay is a standardized laboratory test for determining the oil yield from
oil shale to be expected from a conventional
shale oil extraction. A 100 gram oil shale sample crushed to <2.38 mm is heated in a small aluminum
retort to 500 °C (930 °F) at a rate of 12°C/min (22°F/min), and held at that temperature for 40 minutes.[1] The distilled vapors of oil, gas, and water are passed through a
condenser and cooled with ice water into a graduated
centrifuge tube. The oil yields achieved by other technologies are often reported as a percentage of the Fischer Assay oil yield.
The original Fischer Assay test was developed in the early low temperature coal retorting research by
Franz Joseph Emil Fischer and Hans Schrader.[2] It was adapted for evaluating oil shale yields in 1949 by K. E. Stanfield and I. C. Frost.[3]
^Heistand, Robert N. (1976).
"The Fischer Assay, standard method?"(PDF). San Francisco: Symposium on oil shale, tar sands, and related materials—production and utilization of synfuels. Archived from
the original(PDF) on 2012-02-11. Retrieved 2008-08-18.