Crude oil is a raw material which is composed of different chemical with varying chain lengths of hydrogen and carbon atoms. To separate the hydrocarbons into their different fractions, distillation techniques can be used. There are commonly three different distillation methods used in petroleum refining. The first of these methods is True Boiling Distillation (TBP). With petroleum processing the boiling rang of the crude gives an indication of the quantities of the various products present.¹ TBP provides a reliable tool for characterizing of crude oil and petroleum in terms of their boiling point distribution.¹ It completes this by separating the individual components of the crude into individual mixtures components in order of boiling point.¹ Refiners use this information to model the crude distillation column.¹ However TBP is costly and takes significant time to analysis so it’s not always the best method or most practical for daily monitoring of crude distillation unit operation.¹

The second method of distillation is ASTM Distillation. In this process atmospheric distillation of petroleum products is performed using batch distillation unit to determine quantitatively the boiling range characteristics of the products.² By performing a simple batch distillation the boiling range can be found.² The information generated then can be used to find composition, properties, and the behavior of the fuel during storage and use. It also creates limits of use of petroleum products in commercial contract agreements, process refinery, control application, and for compliance to regulatory rules.

The last form of distillation is Equilibrium Flash Vaporization (EFV). This process Involved heating a flowing feed and separating of liquid and vapor in a flash drum.³ This process generates information about the vapor-liquid equilibrium, which can then be used for the design of equipment to separate the different components of a crude hydrocarbon mixture.⁴ This type of data is often reported as an isobaric curves on a plot showing vaporization vs. temperature.

References

1. BOILING POINT DISTRIBUTION OF CRUDE OILS BASED ON TBP AND ASTM D-86 DISTILLATION DATA Petroleum & Coal ISSN 1337-7027 Petroleum & Coal 53 (4) 275-290, 2011 Angel Nedelchev, Dicho Stratiev, Atanas Ivanov, Georgy Stoilov Lukoil Neftochim Bourgas

2. Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure

3. 3.FSC 432: Petroleum Processing- Equilibrium Flash Vaportization- Course Webpage

4. D. F. Othmer, E. H. Ten Eyck, S. Tolin Equilbrium Flash Vaporization of Petroleum Crude Oils or Fractions- Method and Apparatus for Determination-