There are multiple distillation methods used in the industrial processes of refining crude oil. Three notable processes of distillation are True Boiling Point, ASTM Distillation, and Equilibrium Flash Vaporization. The best process in petroleum refining for distillation is determined by three factors, the number of plates, the reflux ratio, and the steam-to-feed ratio. These parameters are what dictates why the order of the distillation methods previously mentioned are in descending order of best separation methods.

True Boiling point Distillation (TBP) uses a distillation operation that utilizes more than 100 theoretical plates and a high reflux ratio. This is used in petroleum refining not only as the idealized method for best possible separation in distillation but also is used to characterize crude oils and create a significant component of crude essay.

ASTM Distillation is not as good of a separation method as TBP but is usually used for refinery products and property calculations and correlations for distillate fractions. This method does not operate in the presence of contacts plates and has a reflux ratio of 0. This method works in contrast with the TBP Distillation method.

Equilibrium Flash Vaporization has a heater that heats a flowing feed.  The heated feed then is deposited into a flash drum and involves the separation of the liquid and vapor. Equilibrium Flash Vaporization is useful for obtaining data for flashing operations within a refinery.