About the Project

The CO₂ fixation in basaltic rock in SW Iceland

The reduction of anthropogenic CO₂ emissions is considered one of the main challenges of this century. By capturing CO₂ from variable sources and injecting it into suitable deep rock formations, the carbon released is returned back where it was extracted instead of freeing it to the atmosphere.  This technology might help to mitigate climate change as injecting CO₂ at carefully selected geological sites with large potential storage capacity can be a long lasting and environmentally benign storage solution. The CO₂ at Hellisheidi Iceland will be stored as solid calcium carbonate mineral in basaltic rock. 

Why basalt and why Iceland?

Basaltic rocks are one of the most reactive rock types of the Earth’s crust and contain reactive minerals and glasses with high potential for CO₂ sequestration. More than 90% of Iceland is made of basalt.

The project at Hellisheidi

A mixture of water and steam is harnessed from 2000 m deep wells at Hellisheidi geothermal power plant. The steam contains geothermal gases, i.e. CO₂. It is planned to dissolve the CO₂ from the plant in water at elevated pressure and then inject it through wells down to 400-800 m, just outside the boundary of the geothermal system. The liquid will react with calcium from the basalt and form calcite. This process occurs naturally and the mineral calcite is stable for thousands of years in geothermal systems. The proposed experiment will aim at accelerating these natural processes. 

Near zero CO₂ emission

It shall be kept in mind that the amount of pores in the basaltic rock is limited. Therefore, the results from the Hellisheidi experiment will not safe the world’s climate. However, the experiment might demonstrate that a “near zero CO₂ emission” geothermal power plant is a possibility and even the option to store the main part of Iceland’s CO₂ emission in a safe way.  This technology, if proved successful, can then be exported to other basaltic terrains of the Earth. 

Project consortium

The University of Iceland, Reykjavik Energy, CNRS in Toulouse and Columbia University in N.Y., have established a research group. Reykjavik Energy, one of the world’s leading companies in harnessing geothermal energy, will provide the infrastructure of its geothermal fields at Hellisheidi, and create a natural laboratory for the research. The area has been extensively studied.
The research will be a combined program consisting of field scale injection of CO₂ at Hellisheidi, laboratory based experiments, large scale plug-flow experiments, study of natural CO₂ waters as natural analogue and state of the art geochemical modelling.

Knowledge for the future

The bulk of the research will be performed by PhD students at the University of Iceland, thereby generating the human capital and expertise to apply the advances made in the project in the future.