Refining processes for oil sands
adds hydrogen atoms or removes carbon atoms, which
converts the bitumen into a product similar to
conventional light crude oil.
Upgrading is usually a two stage
process. First, bitumen is heated and hydrogen is
added under high pressure to break down the large
hydrocarbon molecules into simpler, smaller
compounds. This process is called hydro-cracking.
Some upgraders also use a process called coking,
which removes carbon from the bitumen to produce
lighter hydrocarbons and coke, a carbon material
that resembles finely ground asphalt. During the
second stage, hydrogen is added to the hydrocarbon
compounds to stabilize them and remove impurities
such as sulphur. This process is called
hydro-treating. After this process, the oil is ready
to be further broken down, like the crude oil in a
distilling tower that breaks up the oil into
different products using heat.