EXPLANATION
This is a complex procedure involving many interacting variables. It is most important that at the time of first use of a new apparatus, its components be checked in detail as described in the method. This method describes a procedure for distilling heavy hydrocarbon mixtures having initial boiling points greater than 150° C (300° F), such as heavy crude oils, petroleum distillates, residues, and synthetic mixtures. It employs a potstill with a low pressure drop entrainment separator operated under total takeoff conditions. The maximum achievable temperature, up to 565° C (1050° F) is dependent upon the heat tolerance of the charge.
TEST SUMMARY
A weighed volume of the sample is distilled at absolute pressures between 6.6 and 0.013 kPa (50 and 0.1 mm Hg) at specified distillation rates. Cuts are taken at preselected temperatures. Records of vapor temperature, operating pressure, and other variables are made at intervals, including at each cut point. The mass and density of each fraction are obtained. From this the distillation yields by mass and volume are calculated.
TEST PRECISION
The bias of this test method has not been determined.