In petroleum refining, there are three different distillation methods used to generate laboratory data. The three distillation methods are: True Boiling Point Distillation (TBP), ASTM Distillation (ASTM), and Equilibrium Flash Vaporization (EFV). They all have their different purposes and all are vital in a different way. The degree of separation for the various methods are vastly different, with the greatest degree of separation occurring in True Boiling Point Distillation and the lowest degree of separation occurring in Equilibrium Flash Vaporization. Each of these methods have different applications in a given refinery.

The first of the three methods, True Boiling Point Distillation, uses a batch distillation operation that incorporates more than 100 theoretical plates and a high reflux ratio of 100. It is an ideal method used to generate the best separation possible, and is used to characterize crude oils and constitute a significant component of crude assay.

The second, ASTM Distillation, also uses batch operation, the difference from True Boiling Point Distillation is that it operates without the presence of contact plates, and has a reflux ratio of zero. This method is used for refinery products and property calculations and correlations for distillate fractions

The third and final method, Equilibrium Flash Vaporization, involves heating a flowing feed and the separation of the liquid and vapor in a flash drum, and generates the lowest degree of separation of any of the methods. This method provides useful data for flashing operations in the refinery.

References:

https://cms.psu.edu/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=F20C6357261A4AE2A750C141B721E8C1