CarbFix is a project in Iceland intended to lock away carbon dioxide by reacting it with basaltic rocks. Work on the project began in 2007. The CarbFix team involves American and Icelandic researchers including Iceland geologist Sigurdur Reynir Gislason serving as chief scientist, project technical manager Bergur Sigfusson, manager Juerg Matter who works with Columbia University's Lamont-Doherty Earth Observatory and scientific overseer, Wallace S. Broecker (also with Columbia). Reykjavik Energy has supplied almost half the $10 million spent thus far on CarbFix. Other sponsors include U.S. and Icelandic universities. In addition to finding a new method for permanent carbon dioxide storage, another objective of the project is to train scientists for years of work to come.
Contents
Theory
Carbonated water is injected into the rock and hopefully reacts with the Ca and Mg present. This is called enhanced weathering, calcium and magnesium are present in basalt - but rarely as simple oxides where the equations would be simple:
However silicate minerals of these elements are common in basalt, so an example reaction might be:
as a result CO2 is locked away with no dangerous byproducts.
Practicalities
Drilling and injecting carbonated water at high pressure into basaltic rocks at Hellisheidi is not without cost.
This 10 million dollar project is due to commence carbon injection in October 2011. The funding was supplied by the University of Iceland, Columbia University, France's National Centre of Scientific Research, the United States Department of Energy, the EU, Scandinavian funds and Reykjavik Energy.
Possible problems
These reactions are exothermic and reversible if the rock is later heated.
The nearby Hengill volcano, generated a swarm of low magnitude earthquakes as a result of pumping water without the CO2, with 250 quakes being reported on 13 September 2011. There have been earthquakes reported there due to the water pumping previously. Proceedings at the 2010 World Geothermal Congress reported that reinjection at Hellisheidi had induced seismic activity.
Other gases
There are reports that not only CO2 is intended to be fixed. Hydrogen sulfide may also be injected.
Current status
The CarbFix project showed in 2016 that 95% of the injected 250 tonnes of CO2 were solidified into calcite in 2 years, using 25 tonnes of water per tonne of CO2.