(Equivalent Test Method: ISO 8708)
GENERAL
This test provides an estimate of the yields of fractions of various boiling ranges, and is therefore valuable in technical discussions of a commercial nature. This test method corresponds to the standard laboratory distillation efficiency referred to as 15/ 5. This test method can be used for any petroleum product except LPG, very light napthas, and fractions having initial boiling points above 400° C. This test method employs a fractionating column having an efficiency of 14 to 18 theoretical plates operated at a reflux ratio of 5:1.
TEST SUMMARY
A weighed sample of 1 to 30 L of stabilized crude petroleum is distilled to a maximum temperature of 400° C in a fractionating column having an efficiency at total reflux of at least 14 but not greater than 18 theoretical plates. A reflux ratio of 5 to 1 is maintained at all operating pressures. Temperature, pressure, and other variables are recorded at intervals and at the end of each cut or fraction. The mass and density of each fraction or cut are obtained. Distillation yields by mass are calculated from the mass of all fractions. Distillation yields by volume of all fractions are calculated from mass and density. From these data the TBP curves in mass or volume %, or both, versus atmospheric equivalent temperature are drawn.
TEST PRECISION
The repeatability of this test method is being reviewed. Following reproducibility can be obtained:
Bias of this test method has not been determined.