Fuel for thought

The use of low-quality sources of petroleum, such as tar sands, will dramatically raise global greenhouse gas emissions according to a new study.

The work is reported in the paper ‘Risks of the oil transition’, published in the new Institute of Physics online journal, Environmental Research Letters (ERL).

Lead author Professor Alex Farrell of the University of California, Berkeley said: ‘Liquid fuels for transportation are increasingly coming from a wide range of sources other than conventional petroleum. We call this the oil transition and we conclude that the environmental risks associated with this transition are much bigger than the risk to a country’s economy or the security of their fuel supply.’

According to the report, tar sands are currently one of the biggest unconventional sources for petroleum. Bitumen, a very think mixture of organic liquids, is mined from the tar sands. Natural gas is then bubbled through the bitumen to separate the impurities, mostly sulphur. The use of natural gas for removing impurities and then in refining tar sands into oil is a highly energy intensive process itself, even before the resulting oil is refined into gasoline and then burned in vehicles.