(653j) Characterization of Heavy Petroleum Fractions and Its Application in Design and Operation of Upgrading Related Processes

As needs for use of heavy and unconventional oils are on the rise, conversion of these oils into light and middle distillates is becoming increasingly important. The nature and constituents of heavy oils and heavy residues are significantly different from those of light and conventional oils [1]. In this presentation first the differences between light and heavy oils especially from compositional and elemental points of views are discussed. Heavy oils are rich in elements such as sulfur, nitrogen and metals. Methods used for characterization of light and conventional oils cannot be directly used for heavy oils and their fractions. Traditional methods used for estimation of thermophysical properties of light fractions are not applicable to those of heavy fractions. In the second phase of this presentation we discuss appropriate characterization methods for heavy fractions and residues. Properties and specification which can be measured in laboratory to characterize heavy oils and fractions are discussed. It will be shown how the amounts of hydrogen, nitrogen, sulfur and metals in a heavy fractions can be estimated from those of its original crude oil. Data for properties of very heavy residues are used to demonstrate accuracy of several characterization methods in representing amounts of various compounds in the mixture. In addition method of experimental measurement on the rate of dissolution of light gases into heavy oils for upgrading purposes under different conditions of temperature and pressure is presented.

In the final stage latest processes developed for upgrading heavy oils and heavy residues, advantages and disadvantages of each process are reviewed [2]. A set of data measured on conversion of a heavy petroleum fraction into lighter products at different operating conditions are used to demonstrate how product specifications and conversions can be estimated using feed specifications and appropriate characterization method. In summary several characterization schemes utilizing measurable properties for heavy oils and residues will be presented which can be used to properly estimate thermodynamic and physical properties needed for optimum design and operation of upgrading units.

[1] Riazi, M. R., “Characterization and Properties of Petroleum Fractions,” ASTM International, 2005. 430p. (2^nd Print: 2007)

Web: http://www.astm.org/BOOKSTORE/PUBS/MNL50.htm

[2] Riazi, M. R., Eser, S., Agrawal, S. S., Pena Diez, J. L., “Petroleum Refining and Natural Gas Processing” ASTM International, Conshohocken, PA, USA, 2013. 811p.

Web: http://www.astm.org/BOOKSTORE/PUBS/MNL58.htm