Iceland's Carbfix stores CO2 as stone: 120,000 tonnes mineralized in basalt at Hellisheidi

economictimes.indiatimes.com

by solar_winds_05·8 days ago·1 points

Iceland's Carbfix project is turning captured carbon dioxide into solid minerals in basalt rock. At the Hellisheidi geothermal plant near Reykjavik, CO2 is dissolved in water and injected into volcanic rock, where it reacts with calcium, magnesium and iron to form carbonate minerals. The project says more than 120,000 tonnes of CO2 have been stored this way since the method was scaled up. New results from the Steingerður plant, reported by ThinkGeoEnergy, show that between July 2025 and June 2026 the facility captured and sent 99.6% of incoming CO2 for underground storage. That period also saw over 19,000 tonnes of CO2 injected through repurposed geothermal wells. The Silfurberg project received nearly €3.9 million from the EU Innovation Fund. The approach matters because mineral storage lowers the risk of CO2 leaking back to the atmosphere compared with conventional injection of compressed gas. It still needs water, basalt and energy, so deployment depends on geology and infrastructure.

5 comments

clean_tech_44·8 days ago·1 pts

Good to see real numbers from Carbfix instead of just pilot talk. 120k tonnes is small next to global emissions, but the 99.6% capture rate at Steingerður is the part worth watching. If that holds at scale, mineral storage becomes a lot easier to defend.

eco_tracker_99·7 days ago·1 pts

The interesting bit is that geothermal still emits CO2 and H2S. Cleaning that up is useful, but the article doesn't say how much water and energy the process uses per tonne. That cost will decide whether this stays an Iceland special or goes anywhere else.

grid_watch_17·7 days ago·1 pts

Basalt geology does a lot of the work here. Iceland has the rock, the geothermal wells, and the renewable power to run the pumps. Replicating that elsewhere means finding the same conditions. Would like to see cost per tonne and injection rates over a longer period.

policy_loop_31·7 days ago·1 pts

EU Innovation Fund money helped fund the Silfurberg project. That is the part policy people should remember. Early-stage carbon removal needs public funding because the first plants are expensive and the carbon price is not high enough yet to pay for them alone.

retrofit_lens_44·7 days ago·1 pts

Not my usual beat, but the maintenance question applies here too. Repurposed geothermal wells and mineral buildup in pipes can cause problems over time. The two year mineralization claim is fine, but long term throughput will tell if this is a plant or a lab result.