Carbon dioxide could be stored underground for millions of years

The SACS (Saline Aquifer CO2 Storage) project is being carried out by a team of researchers from the oil industry, power generating companies and research institutions around Europe. The team has been studying the effect of pumping carbon dioxide into a layer of porous sandstone between the Shetland Islands and Norway.

The carbon dioxide used in the SACS research has been separated from methane extracted from Sleipner Field in the North Sea by the Norwegian company, Statoil. The methane contains 9% carbon dioxide, higher than is permitted, so instead of venting the carbon dioxide to the atmosphere as would usually occur, it is being returned underground – although not in the exact same place that it has been extracted from.

However, the real benefit to the environment will come when fossil fuel power stations are able to capture carbon dioxide from their emissions – which could then be stored underground, Dr Andrew Chadwick of the British Geological Survey – one of the members of the team – said to edie.

This is a long-term solution, he says. “There are naturally occurring CO2 fields in the United States and they have been there for millions of years.” There are also oil and gas fields in places such as the North Sea that have the potential for carbon dioxide storage, he said.

Chadwick is keen to point out that the SACS project is completely different to a scheme that another group of researchers had intended to carry out last year to pump carbon dioxide into the water at the bottom of the ocean. That would have had serious consequences for marine life in the area, he said.

The SACS method of sequestration is completely safe environmentally, he says. Objections by environmental groups are “more philosophical than practical”, he explains, with groups preferring emission reductions rather than sequestration.