Overall carbon cost of fuel from Canadian oil sands
Gasoline and diesel fuel extracted and refined from Canadian oil sands will release about 20% more carbon into the atmosphere over the oil’s lifetime than fuel from conventional crude sources in the United States, according to a study by the University of California and Stanford University.
The researchers used a life-cycle, or “well-to-wheels,” approach, gathering publicly available data on 27 large Canadian oil sands production facilities. The study found the additional carbon impact of Canadian oil sands was largely related to the energy required for extraction and refining.
Canadian oil sands are extracted using 2 processes, both of which are energy intensive. Oil close to the surface can be mined, but still must be heated to separate the oil from the sand. Deeper sources of oil are extracted on-site, also called in situ extraction, requiring even more energy when steam is injected underground, heating the oil to the point it can be pumped to the surface. The extracted oil product, known as bitumen, can be moved to refineries in the United States or refined on-site to upgraded synthetic crude.