Q:
What is bitumen?
A:
Bitumen has been described as
hydrogen-deficient oil. In order to be used, bitumen needs
to be upgraded by either removing most of the carbon, a
process known as "coking," or adding hydrogen,
a process known as "hydrogenation" or "hydrocracking."
This has to be done because bitumen contains extremely large
hydrocarbon molecules. The natural gas you burn in your
furnace or stove consists of one or two carbon atoms surrounded
by 4 to 6 hydrogen atoms. These natural gases are known
as methane and ethane.
The
gasoline you use in your car is mostly octane: a chain of
8 carbon atoms surrounded by 18 hydrogen atoms. Diesel oil
can consist of a chain of 20 to 30 carbon atoms and up to
62 hydrogen atoms.
The
longer the carbon chain the higher the temperature at which
it boils, the harder it is to get it to burn, and the thicker
or more "viscous" the oil. Bitumen is often composed
of molecules containing as many as 2000 carbon atoms! As
a result it is almost impossible to get it to burn, it will
not boil, and it is extremely thick and tarry. It is often
described as similar to cold molasses in consistency. In
its natural state it cannot be refined into useful products
such as diesel oil or gasoline or natural gas. To do this
the long chain molecules have to be split into smaller pieces
by taking carbon out and adding hydrogen to the resulting
synthetic oil.
