Bitumen (bitumen
60/70) is a mixture of aromatics, resins, saturates and asphaltenes.
The saturates are nonpolar material including branched, cyclic saturated hydrocarbons
and linear hydrocarbons. The asphaltenes and resins have polar substituents.
Asphaltenes are insoluble in an excess of pentane (or heptanes) whereas the
resins are miscible with pentane (or heptanes).
amount of asphaltenes, aromatics, saturates and resins in bitumen (bitumen 60/70) may be measured whit
a SARA (Saturate, Aromatic, Resin and Asphaltene) analysis method. amounts of
asphaltenes, resins, saturates, and aromatics in bitumen (bitumen 60/70) is dependent on the
geographical location of the bitumen (bitumen
60/70) and the test method used.
heavy petroleum liquids have an API (American Petroleum Institute gravity)
gravity of less than 20°. Extra heavy petroleum liquids is defined as a dense petroleum
liquids with an API (American Petroleum Institute gravity) gravity of less than 10°. Bitumen (bitumen 60/70) has an API gravity
of less than 10° and an extremely high viscosity. Bitumen (bitumen 60/70) is distinguished from extra heavy petroleum
liquid by the degree in which it has been degraded from the original crude oil.
Often bitumen (bitumen 60/70) is present as a solid and does not flow at 25
Degrees Celsius temperature.
After extraction of bitumen (bitumen 60/70) it must be transported from the producer to
refineries for processing. The transportation of bitumen (bitumen 60/70) by pipeline requires
that the viscosity of bitumen (bitumen 60/70) be low enough so that the pumping
requirements and the size of the pipeline are economically optimal. There are
several methods which bitumen (bitumen 60/70)
may be transported by pipeline. These
methods include; core annular flow; dilution; oil/water emulsion formation;
heating; and partial field upgrading.
Dilution is a conventional method that producers have used to transport bitumen (bitumen 60/70) . Dilution requires
large quantities of diluent to reduce the viscosity and make the bitumen (bitumen
60/70) easier to pump through the pipeline. At the refinery, the diluent
is typically separated from the bitumen
(bitumen 60/70) and pumped back to the production site via separate
pipelines for reuse.
Typically, in order for pipeline transportation of bitumen (bitumen
60/70) to be possible, diluent is
added to the bitumen (bitumen 60/70) to prepare a mixture of bitumen (bitumen
60/70) and diluent. Diluents are
mixtures of hydrocarbon solvents or hydrocarbon solvents which are added to the
bitumen to improve the movement of the
bitumen through a conduit.
