ASTM D2892 for distillation of crude petroleum (15-Theoretical Plate Column)
8. Sampling
8.1 Obtain a sample for distillation in accordance with instructions given in Practice D4057 or D4177. The sample must be received in a sealed container and show no evidence of leakage.
8.2 Cool the sample to between 0 and 5°C by placing it in a refrigerator for several hours (preferably overnight) before opening.
8.3 If the sample appears waxy or too viscous, raise the temperature to 5°C above its pour point.
8.4 Agitate the sample by whatever means are appropriate to its size to ensure that it is well-mixed.
8.5 Determine the water content of the sample by Test Method D4006 or any other suitable method. If the water content exceeds 0.3 % volume, the sample shall be dehydrated prior to fractional distillation. A suitable practice for dehydration of wet crude oil samples is described in Appendix X1.
NOTE 3 - Attempts to distill wet crude oil samples in glass columns might result in breakage of the glassware, which poses a potential fire hazard. Moreover, the presence of water will effect the accuracy of distillation yield in the naphtha region. These effects are more pronounced for heavy crude oils, containing low amounts of hydrocarbons boiling below 100°C, than for light crudes where there is usually sufficient hydrocarbon vapor generated to form an azeotrope and drive the water vapors through the column without problems.
9. Preparation of Apparatus
9.1 Clean and dry the distillation column and all the ancillary glass apparatus before the distillation begins.
9.2 Ensure that the system is leak-free and all heaters, control devices, and instruments are on and in working order. A clock or other timing device should be ready for use.
