Carbfix is an Icelandic company that has developed an approach to capturing and storing CO2 in water, and its injection into subsurface basalts. Once in the subsurface, the injected CO2 reacts with the host rock forming stable carbonate minerals, thus providing storage of the captured gas.
Approximately 200 tons of CO2 were injected into subsurface basalts in 2012. Research results published in 2016 showed that 95% of the injected CO2 was solidified into calcite within 2 years, using 25 tons of water per tonne of CO2. Since this time this approach has been upscaled at Hellisheiði and ongoing research is implementing this approach at other sites across Europe.
Background
Carbfix was founded by the then Icelandic President, Dr Ólafur Ragnar Grímsson, Einar Gunnlaugsson at Reykjavík Energy, Wallace S. Broecker at Columbia University, Eric H. Oelkers at CNRS Toulouse (France), and Sigurður Reynir Gíslason at the University of Iceland to limit the Greenhouse gas emissions in Iceland. Reykjavik Energy supplied the initial funding for Carbfix. Further funding has been supplied by The European Commission and the Department of Energy of the United States. In addition to finding a new method for permanent carbon dioxide storage, another objective of the project was to train scientists.
Method
CO2 is captured either by its dissolution in water from power plant exhaust, or directly from the atmosphere by air capture followed by its dissolution in water. The carbonated water is injected into the subsurface where it reacts with the Ca and Mg present in the rock. Calcium and magnesium are present in rocks - but rarely as oxides where the reactions would be simply:
CaO + → CaCO3
MgO + CO2 → MgCO3
However silicate minerals of these elements are common in many rocks, such as basalt, so an example reaction might be: Mg2SiO4 + 2CO2 → 2MgCO3 + SiO2 as a result CO2 is locked away with no dangerous byproducts.
Practicalities
Drilling and injecting carbonated water at high pressure into basaltic rocks at Hellisheiði has been estimated to cost less than $25 a ton.
This project commenced carbon injection in 2012. 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, Nordic funds and Reykjavik Energy.
These funding sources include the European Union's Horizon 2020 research and innovation programme under grant agreements No. 764760 and 764810. The European Commission through the projects CarbFix (EC coordinated action 283148), Min-GRO (MC-RTN-35488), Delta-Min (PITN-GA-2008-215360), and -REACT (EC Project 317235). Nordic fund 11029-NORDICCS; the Icelandic GEORG Geothermal Research fund (09-02-001) to S.R.G. and Reykjavik Energy; and the U.S. Department of Energy under award number DE-FE0004847.
Cost is around US$25 per tonne of CO2.
Challenges
This approach requires substantial water and the presence of reactive rocks, which are not available in all localities.
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 due to the injection of waste water in the area. Proceedings at the 2010 World Geothermal Congress reported that reinjection at Hellisheiði had induced seismic activity.
Criticisms
In March 2023, Carbfix was criticised in the Icelandic media when Mannlíf, an electronic news publication, revealed that the partnership's head of communications had been an outspoken climate change denialist. Ólafur Teitur Guðnason, Carbfix's principal media spokesperson, worked as a columnist for Viðskiptablaðið, an Icelandic right-wing newspaper, during the years 2004–2007. In his articles, Ólafur Teitur had expressed doubts that climate change was caused by human actions and maintained that media coverage of environmental affairs was fearmongering. Ólafur Teitur replied with a Facebook post, stating that his former position was wrong and he had changed his mind since then: "I would find it burdensome if my earlier views would cast aspersions to the great work done by my colleagues at Carbfix since 2007." In a follow-up piece, Mannlíf claimed that Ólafur Teitur's columns had all the characteristics of fake news, presenting propaganda and pseudoscience as scientific facts.