What do the Adriatic coast, Oman, Papua New Guinea and Caledonia have in common?
They all have large deposits of Peridotite – a silicate rock that could play a huge part in mitigating climate change.
Scientists at the Earth Science Research Centre at Sultan Qaboos University in Oman have been examining how Peridotite might be used to absorb carbon dioxide. Peridotite readily reacts with carbon dioxide, converting it into calcite, a solid mineral:
“Oman is one of the few places where the rock appears on the earth’s surface. It also boasts the largest such rock formation in the world stretching more than 600 kilometres, with a width of 150 kilometres and a depth of 3 kilometres.”
This exposed rock absorbs 100,000 tons of carbon dioxide every year from the atmosphere above Oman. However, researchers believe that far more carbon dioxide could be locked up in the rock simply by drilling and pumping liquefied carbon dioxide into the rock. Alternatively, pulverised rock could be mixed into liquefied carbon dioxide until it forms a calcite solid.
This all sounds promising until the awkward matter of cost is brought into the discussion. Although much cheaper that other CCS storage options, drilling, and/or pulverising Peridotite turns out to be far too expensive at present to make it worthwhile. For example, in 2012 Dutch companies commissioned the Oman scientists to drill, pulverise and transport a shipment of Peridotite to the Netherlands. However, the plan failed due to the high costs involved.
For the time being, the cheapest and easiest way of dealing with carbon emissions is simply not to make them in the first place… trying to clean up afterwards will always by expensive by comparison.