Mineral Sequestration of CO2 Commences in Iceland
A field scale injection of CO2 into basalts in Hellisheidi, Iceland, was started in late January this year. It is a part of the international CarbFix project, a combined industrial and academic research program, led by power and utility firm Orkuveita Reykjavikur and the University of Iceland. The physical injection is preceded by various theoretical work, laboratory research, modeling and design of the process.
Three Main Objectives
CarbFix is aimed at three principal objectives;
- increase measurably our understanding of the long‐term fate of CO2 injected into the subsurface,
- to develop new technology to facilitate safe and permanent geologic carbon storage, and
publicize the results of this research allowing them to be applied internationally.
Unique to CarbFix is its connection to the Hellisheidi geothermal power plant, allowing for capture of otherwise emitted CO2 in addition to CO2 transport and mineral sequestration.
Rather than injecting CO2 directly into basaltic formations, CarbFix scientists and technicians have developed a technology to dissolve CO2 in water during injection. Once dissolved CO2 is no longer buoyant compared to pore fluids, improving considerably security due to decreased leakage risks. This approach of solubility trapping also promotes mineralization of injected CO2 and thus facilitates the safe long-term sequestration of CO2 in the subsurface.
Two Exploratory Injection Phases
The first phase of the injection, which started late January and has to date proceeded as planned, involves a month long injection of about 170 tons of pure CO2 from a geothermal well. The main objective of the first phase is to validate the developed injection technology and provide a platform for a full carbon capture and storage (CCS) cycle at Hellisheidi power plant.
The second phase of the injection will involve a six-month-long injection of 1,200 tons of geothermal gas mixture from the Hellisheidi power plant. The gas mixture consists of approximately 75% CO2 and 25% H2S. A critical part of this phase is the currently ongoing development of a new technology aimed at separating geothermal flue gas from Hellisheidi power plant into streams of gases that can be disposed of back into the geothermal system.
Orkuveita Reykjavikur is committed to decreasing gas emissions from its geothermal power plants. Collaboration with academic research institutes in the development of new methods and technology is an important part of that commitment. These new methods aim at decreasing gas emissions in a more environmentally friendly way than currently available industrial methods.