Categories
Carbon Capture

61: Turning carbon in the air into stone

Problem:

There is virtually blanket scientific consensus that atmospheric CO₂ is the root cause of this rapid AGW, and that humanity must stop burning fossil fuels to halt it. Recently, however, there has also been growing consensus that decarbonisation on its own will not be enough.

Solution:

Capture the air and store it safely.


Several direct air capture (DAC) systems are in operation, in Iceland, in Switzerland, In Canada and in the USA.

In 2006, CarbFix was initiated jointly by the 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 University of Iceland to limit GHG emissions in Iceland.

Before the injection into subsurface basalt started in CarbFix, the consensus within the scientific community was that it would take decades to thousands of years for the injected CO₂ to mineralise.

During the first 6 years of the project, the main focus was to optimize the method through lab experiments, studies of natural analogues, and characterization of the CarbFix pilot injection site, often referred to as the CarbFix1, located 0.6 mi ( 3 km) SW of the Hellisheidi power plant in south-west Iceland. Design and construction of gas capture, injection and monitoring equipment was carried out simultaneously.

From January to March 2012, 193 tons (175 tonnes) of pure CO₂ were dissolved and injected into subsurface basalt at about 1600 ft (500 m) depth at about 35°C, and from June to August, 73 tonnes of 75% CO₂-25% H2S gas mixture from the Hellisheidi geothermal plant were injected under the same conditions.

Research results published in 2016 would indicate that 95% of the injected CO₂ had been solidified into calcite within 2 years, using 25 tonnes of water per tonne of CO₂.

Following the success of the pilot injections, the process was scaled up to industrial scale at Hellisheidi geothermal power plant, with injection of 65% CO₂-35%H2S gas mixture at about half a mile (800 m) depth and about 230°C at the Husmuli injection site, located 1 mi (1,5 km) northeast of the power plant.

The injection has been an integral part of the operation of the Hellisheidi Power Plant since June 2014.

In 2016, the injection operations at the Hellisheidi Plant were scaled up again, doubling the amount of gases injected. In 2017, 10,000 tonnes of CO₂ were “digested” by CarbFix.

The injection is ongoing today and at the end of 2018, approximately 37,500 tons (34,000 tonnes) of CO₂ had been captured and injected at Hellisheidi.

At current capturing capacity, approximately 1/3 of the CO₂ and about 3/4 of the H2S emissions from the plant are being re-injected, or approximately (11,ooo tons (10,000 tonnes) of CO₂ and about 6,000 tonnes of H2S annually

Reykjavik Energy had 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 for years of work to come.

Several universities and research institutes have participated in the project under the scope of EU funded sub-projects, including Amphos 21, Climeworks and the University of Copenhagen.

Recently carbon capture and storage approach has been upscaled at Hellisheiði and ongoing research is implementing this approach at other sites across Europe, thanks to the ubiquity of basalt which covers most of the oceanic floors and around 10% of the continents. Large basaltic areas are to be found in Siberia, Western India, Saudi Arabia and the Pacific Northwest.

In June 2019, A Letter of Intent was signed between the Prime Minister of Iceland, Reykjavík Energy, the Aluminium and Silicon Industry in Iceland (Elkem, Fjarðarál, PCC and Rio Tinto), the Ministry for the Environment and Natural Resources, the Ministry of Industries and Innovation and the Ministry of Education, Science and Culture for exploring further exploitation of the CarbFix method for large emitters in Iceland was signed in Reykjavík.

The companies will each look for ways to realize carbon neutrality in 2040, as stated in the announcement from the Government Offices.

Tomorrow’s solution: Climeworks of Switzerland

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