In May of this year, British media outlet The Guardian made drastic changes to its style guide when it comes to discussing the environmental crises facing the world. Instead of climate change, Guardian’s Environment Editor Damian Carrington wrote, the preferred terms would be “climate emergency, crisis or breakdown;” and “global heating” would be favoured over “global warming.”
While scientists had previously designated that a 2°C rise in global temperatures was the threshold to avoid ecological disaster, they recently lowered that threshold to 1.5°C. According to the World Meteorological Organisation, the planet is already one degree warmer than it was before widespread industrialisation. To avoid climate catastrophe, it’s increasingly clear that we will not only have to drastically reduce carbon emissions, we will also need to sequester some of the carbon that is currently in the atmosphere. Some technologies for storing carbon – like trees – have existed for millennia. Others, like the CarbFix project developed in Iceland, are virtually brand new.
A rough start
We’ve driven 30 minutes outside of Reykjavík to Hellisheiði power station. Providing electricity and hot water to the Reykjavík capital area since 2006, it’s the world’s third-largest geothermal power plant. It’s also the site of an important project in the global fight against climate change: CarbFix. Since 2012, CarbFix has been capturing carbon dioxide, dissolving it in water, pumping it into the ground, and turning it to stone, thus permanently removing it from the atmosphere.
Geoscientist Dr. Sandra Ósk Snæbjörnsdóttir has been working on research and development of the CarbFix project since 2012. After watching a safety video and donning helmets, goggles, and vests, she takes us on a tour to show us the technology that’s been reported on by the likes of the BBC and The New York Times.
How does CarbFix work?
- Steam from Hellisheiði power station’s turbines is collected. The steam is over 99.5% water vapour and under 0.5% geothermal gases. The most abundant are carbon dioxide (CO2) and hydrogen sulphide (H2S), but the steam also contains gases such as hydrogen, nitrogen and argon.
- The steam is channelled into a tower where it is “showered” with water. Because CO2 and H2S are water soluble, they dissolve to form a sort of sulphurous soda water. The remaining gases, which are less water-soluble, are released through the cooling tower of the power plant.
- The slightly acidic, carbon-infused soda water is then injected into porous basalt rock around 800m (2,626ft) below the earth’s surface.
- The soda water fills the cavities in the porous basalt, where the CO2 and H2S react with metals such as calcium, magnesium, and iron which are released from the rock.
- Within two years, the soda water solidifies into carbonate minerals such as calcite in the case of CO2 – and sulphide minerals such as pyrite (fool’s gold) in the case of H2S, and small amounts of other minerals.
- The carbon is now permanently stored underground – out of the atmosphere for good.
The seed for CarbFix was planted in 2006, the same year the Hellisheiði power station activated its first two turbines. “A professor from Columbia University named Wallace S. Broecker held a lecture here. He introduced the idea of using the natural process which occurs when CO2 and basalt meet in order to bind carbon dioxide,” Sandra tells us. “In 2007 the project formally began.”
Our fist stop is a small, green building the size and shape of a shipping container. “That was our first trial lab,” Sandra tells us, “We call her Geirþrúður. We had all kinds of adventures there while we were trying to get this project off the ground.” First a gas-filtering tower was destroyed, then frost damage impeded progress. When the team was finally ready to pump down the gases, some nearby road works blasted the gas pipeline and the whole project came to a standstill. “The technicians that worked there never called the lab Geirþrúður,” Sandra smiles. “They called her Chernobyl.”
Finally, in 2012, CarbFix conducted its first experiments pumping carbon dioxide into the ground. “We started by pumping down only CO2, but then we did experiments with a mix of hydrogen sulphide [H2S] and CO2.” The reason for this is that when the power plant was opened, it released much more hydrogen sulphide than was expected. The gas caused all sort of issues such as damage to equipment and risk for workers at the site. “On still days, there was a sulphur stink in Reykjavík. There was a risk at one point that this power station would lose its operating license.”
The CarbFix project has changed all that. “Now we are binding around 70-80% of the hydrogen sulphide from the power station, which is about 6,000 tonnes per year, and are binding around one third of the carbon dioxide the station produces, or around 12,000 tonnes per year. We’re tackling a local problem and a global problem at the same time.”
Location, location, location
Hellisheiði has all the raw ingredients necessary for applying CarbFix’s method: power, water, and abundant basalt. “The Achilles heel of this method is that you need a lot of water to pump down the gas.” That’s no problem for Hellisheiði, which injects about 900 litres (240 gallons) of water back into the geothermal reservoir per second. The CarbFix project is also able to use the station’s existing injection wells for injecting gas into basalt, eliminating the need for additional drilling. “All we did was take two of the wells and add a gas pipeline.” Sandra points to a small building, roughly eight by eight metres and two stories tall, dwarfed by all the huge structures around it. “This is the only building we had to add in order to capture our gas.”
In order for CO2-infused soda water to transform into stone below the earth’s surface, it requires the right type of rock. Luckily, Hellisheiði power station sits on top of seemingly endless amounts of basalt, an extremely reactive rock whose calcium and magnesium react with CO2 to form calcite. Another perk of basalt: its porous structure can accommodate virtually limitless amounts of carbon. “Basalt is amazing, it’s like a sponge. You can store a huge amount of CO2 in each square metre. If we were to use all of the water we re-inject to pump down CO2 in this area alone, we could pump down a million tonnes,” Sandra enthuses. Basalt is not only plentiful in Iceland, it’s one of the most common types of rock around the world. “In theory we could bind all the CO2 in the world in basalt.”
On neutral ground
Since 2014, CarbFix has been running smoothly, sequestering and fixating about a third of the carbon dioxide that Hellisheiði power station produces. The next goal, Sandra says, is upping that proportion to make the power station completely carbon neutral. It’s a goal which could happen within the next few years. The CarbFix project itself is in constant development. “We’re trying to find ways to increase the functionality of this method,” Sandra tells us. “We are experimenting now with using seawater to pump the carbon down. The sea floor is basalt and there is a lot of basalt along coastlines. And in places where there maybe isn’t a lot of fresh water that could be used, it would be possible to use seawater instead. The first experiments are very promising.”
In a European project for zero-emission geothermal energy called GECO, the CarbFix team is also looking at different types of rock from Turkey, Italy, and Germany, to see if it could be used to fixate carbon where basalt is not available. “We’re always trying to make the process more efficient. Hopefully it will be used as widely as possible,” Sandra says.
Scaling up
It’s clear that capturing carbon dioxide directly from an emissions source is a positive environmental step. Yet, the reader may wonder, what about emissions that are released directly into the atmosphere, like those from aviation or cars? CarbFix is addressing those emissions in an EU-funded project in co-operation with Swiss company Climeworks. A small white device on Hellisheiði known as “The Arctic Fox” uses technology developed by Climeworks to capture carbon dioxide directly from the atmosphere. The fox has the capacity to capture about 50 tonnes of carbon dioxide per year. That may seem like a small number compared to what the power station is sequestering from its turbines, but the device’s inventors are currently in negotiations to scale up the operations at Hellisheiði.
In Switzerland, CO2 captured using Climeworks’ technology has been put to use in greenhouses and in making carbonated beverages for Coca Cola. “These kinds of projects are part of the process of getting more experience with the tools and developing them further,” Sandra explains. At the moment, Climeworks’ direct air capture technology requires a significant amount of energy and comes with a fairly high price tag. According to a <i>New York Times</i> article published earlier this year, it costs the company between $500-600 (€440-530) to remove a single tonne of carbon from the air. Yet, Sandra says, it’s crucial to support such technologies in their development. “It’s important that as many small projects as possible have the chance to develop and as much experience is gained in as little time as possible, that’s what we need in order to scale up.”
We have the answers
The cost of sequestering Hellisheiði’s emissions is much lower than that of Climeworks’ direct air capture devices. “Here we pay $25 [ISK 3,100/€22] per tonne that we pump down. That includes the cost of the infrastructure, pumping, and labour,” Sandra says. “I know how much money we need to make Hellisheiði carbon neutral. It’s not insurmountable.” The same applies to tackling climate change on a global level, according to Sandra. “We can’t solve this problem without paying a price. But it’s not insurmountable. Though it will get more expensive the longer we wait and the worse the problem gets. It makes a difference if we work quickly, do what we can, and learn about this technology that we’re developing.”
In a world of bad news about climate change, speaking to Sandra is a breath of fresh air. Technology, she says, is ready to take on the huge challenge. “The International Energy Agency did an assessment in 2016 and concluded that with the technology that currently exists or is being developed, we can solve climate change. We don’t need any new discoveries. We just have to speed up the use of the technology that we already have.”
Realism vs. hope
In June, Icelandic government officials, power companies, and aluminium factories signed a joint statement of intent to investigate how the CarbFix method could be applied to big industry in Iceland. The metal industry is one of the biggest contributors to Iceland’s carbon footprint, so the success of the venture could prove crucial in the country’s ability to meet the Paris Agreement goals. However well carbon sequestration may help offset big industry emissions, Sandra warns that it cannot solve the climate emergency alone. “It will never be the case that we can apply this solution and just continue on as we are.”
Carbon fixation technologies do have their opponents, most of whom criticise ventures like CarbFix for validating the belief that technology will singlehandedly solve climate change – with no need for a drastic reduction in emissions. “The criticism of carbon binding projects has been that they will allow people to continue to burn coal and oil and such. In order to reach the Paris Agreement goals, we need to reduce emissions, but we will also need to sequester carbon. Even if we completely stop burning fossil fuels, there are many industrial processes we will need to continue which produce a ton of emissions, like making steel and aluminium. CarbFix could be a solution to tackle those emissions.”
“I think we should always emphasise that there is no magic solution to climate change,” Sandra continues. “We need many solutions. I hope that CarbFix is one of them.” Though it may not be the magic solution, carbon fixation technology can give the public hope, and that’s not something to be discounted either, says Sandra. “I think it’s alright to give people a bit of hope. It’s so hard to constantly be killing everyone’s hope all the time. Then nothing is done.”
Shifting tide
Sandra herself is far from hopeless. She feels that the conversation around climate change is reaching a critical point. “You can feel it. A lot is changing in a really short time. This year alone there’s been a definite change in people’s mentality, people are becoming aware.” Now it’s time to really pull up our sleeves, says Sandra. “When I started my doctorate, the mantra in the science community was that when people open their eyes, scientists will be ready with the solutions. And I think that time is coming now.”
